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Sample records for aprons wharves

  1. Sinopec Invests Heavily for Pipelines, Wharves to Increase Efficiency

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ Sinopec recently said that it would earmark less than 8 billion yuan (US$966.2 million) to complete construction of two pipelines and three wharves by 2006 to improve its downstream operating efficiency.

  2. Probabilistic Assessment for Seismic Performance of Pile-Supported Wharves

    Directory of Open Access Journals (Sweden)

    Hamid Heidary Torkamani

    2013-03-01

    Full Text Available The main objective of this study is to investigate the influence of uncertainties associated with the material properties on the seismic performance of pile-supported wharves. For this purpose a two-dimensional finite difference model, representing typical pile-supported wharf structures from western United States has been constructed using software FLAC2D. Incremental dynamic analysis has been applied to evaluate the response of wharf structure under different levels of seismic loading. The uncertainties at both structural and geotechnical parameters have been investigated using a tornado diagram and a first-Order Second-Moment (FOSM analysis. It has been found that the uncertainties at the dead load of structure, friction angle of rock fill and the porosity of rock fill contribute most to the variability of the displacement ductility factor of the pile-supported wharf structures. Based on the results, design considerations have been provided.

  3. Debris Aprons in the Tempe/Mareotis Region of Mars

    Science.gov (United States)

    Chuang, F. C.; Crown, D. A.

    2003-12-01

    Martian debris aprons are considered to be geomorphic indicators of ground ice, and thus are important in understanding the climate and volatile inventory on Mars. Their presence suggests storage of ice in the Martian regolith, either currently or in the recent geologic past. Recent studies of aprons have focused on the eastern Hellas and Deuteronilus/Protonilus Mensae regions of Mars, which have some of the highest apron concentrations on the planet. However, there are several other locales that have significant populations of aprons. We have initiated a new study of aprons located along the northern lowlands-southern cratered highlands boundary in the Tempe/Mareotis Fossae region (43-55N, 274-294E). Seventy-three apron complexes have been identified in Viking images, and we further document their surface textures, morphometric properties, and topographic characteristics using MOC narrow-angle images, MOLA PEDR profile data, and THEMIS daytime (VIS and IR) and nighttime (IR) images. Debris apron complexes generally consist of one or more lobate deposits that surround individual massifs or small knobs, but have also been observed along the bases of escarpments and inner crater walls. The Tempe/Mareotis aprons have a similar planimetric morphology to those observed elsewhere on Mars. A series of distinctive textures are observed on the surfaces of Tempe/Mareotis aprons that can be attributed to differences in preservation state. Smooth, pitted, ridge and valley, and knobby textures characterize upper apron materials, which often appear to be mantled by a fine-grained deposit. Smooth and ridged erosional textures appear to form in low-lying areas where upper apron material has been removed. The degradation of upper apron material generally begins with a smooth, mantled surface that is gradually removed by sublimation, melting, and/or aeolian activity, which leaves behind a hummocky surface texture composed of knobs, ridges, or both. Further degradation produces

  4. 'Do lead rubber aprons pose an infection risk?'

    International Nuclear Information System (INIS)

    This study was carried out in order to establish whether infection control measures were being undertaken sufficiently on lead rubber aprons within a diagnostic imaging department in the east of England. This study involved the swabbing of a sample of 15 lead rubber aprons used within different areas of the department. Swabs were taken from the area on the underside of the shoulders and from the front of the apron. Each apron was firstly swabbed to determine the current level of microorganism contamination (determination of baseline data) and then again after recommended cleaning with detergent and water (the production of a standard). Comparisons were then made between the number of microorganisms' present (colony forming units/cm2) pre and post-cleaning at each location. Additionally, post-cleaning data was compared for each location. All aprons were found to be contaminated with microorganisms, those identified were Coagulase-negative staphylococci, Staphylococcus aureus, Bacillus, Diphtheroids and some fungal spores. No Methicillin resistant strains of Staphylococcus aureus (MRSA) were identified. Recommended cleaning with detergent and water was found to significantly reduce the amount of microorganisms present (the detergent used was Hospec general purpose neutral liquid detergent). Comparisons of the sample sites found that the front of the apron had lower levels of microorganism contamination post-cleaning than the site at the underside of the shoulders. The results suggest that the lead rubber aprons were not being cleaned sufficiently which has infection control implications for the department. In order for cross contamination to be kept to a minimum an effective infection control policy needs to be employed and this should be to carry out regular cleaning with detergent and water which has been shown can significantly reduce contamination.

  5. APRON: A Cellular Processor Array Simulation and Hardware Design Tool

    Directory of Open Access Journals (Sweden)

    David R. W. Barr

    2009-01-01

    Full Text Available We present a software environment for the efficient simulation of cellular processor arrays (CPAs. This software (APRON is used to explore algorithms that are designed for massively parallel fine-grained processor arrays, topographic multilayer neural networks, vision chips with SIMD processor arrays, and related architectures. The software uses a highly optimised core combined with a flexible compiler to provide the user with tools for the design of new processor array hardware architectures and the emulation of existing devices. We present performance benchmarks for the software processor array implemented on standard commodity microprocessors. APRON can be configured to use additional processing hardware if necessary and can be used as a complete graphical user interface and development environment for new or existing CPA systems, allowing more users to develop algorithms for CPA systems.

  6. Radio-protective aprons during radiological examinations of the thorax: An optimum strategy

    International Nuclear Information System (INIS)

    The current work investigates the most effective type/position of aprons for postero-anterior (PA) and lateral projections of the chest. Two apron-types were investigated: 'Mavig' half apron and Amray light plus' wrap-around apron. The half apron was positioned at the X-ray tube or image receptor side of an anthropomorphic phantom for PA and lateral projections. Radiation dose at positions corresponding to ovaries, uterus and testes was measured with thermoluminescent dosemeters. The wrap-around apron offers a higher level of protection for PA and lateral projections compared with the half apron, regardless of where the latter was positioned, with dose reductions of up to 88% compared with no apron. For the PA position, the half apron should be positioned in a gender-specific way, facing the X-ray tube for females and the image receptor for males. With all apron types/positions, gonadal dose is still clearly evident, from internal scatter, emphasising the importance of other protective practices such as collimation. (authors)

  7. Lead aprons - should they be used for dental x-rays?

    International Nuclear Information System (INIS)

    When dental x-rays are performed it is now becoming increasingly common for dentists to offer their patients a lead apron to wear. However not all dentists are offering lead aprons. Are some dentists being negligent, and should the use of lead aprons for dental patients be mandatory? This article hopefully answers these questions, and in so doing presents a clear picture of what happens when the dentist presses the exposure button on the x-ray machine. (author). 1 tab

  8. Z Specification of Gate and Apron Control Management at Airport

    Directory of Open Access Journals (Sweden)

    Nazir Ahmad Zafar

    2014-01-01

    Full Text Available Modelling of an air traffic control (ATC system is an open issue and has become a challenging problem due to its complexity and increase of traffic at airports and in airspace. Consequently, automated ATC systems are suggested to improve efficiency ensuring the safety standards. It is reported that the number of collisions that occurred at airports surface is three times larger than in airspace. Further, it is observed that gates and aprons congestions cause significant delays at airports; hence, effective monitoring and guidance mechanisms are required to control ground air traffic. In this paper, formal procedure of managing air traffic from gate to enter in the active area of airport for taxiing is provided using Z notation. An integration of gate and apron controllers is described to manipulate the information for correct decision making and flow management. Graph theory is used for representation of airport topology and appropriate routs. In static part of the model, safety properties are described in terms of invariants over the critical data types. In dynamic model, the state space is updated by defining pre- and postconditions ensuring the safety. Formal specification is analysed using Z/Eves tool.

  9. Evaluation of lead aprons and their maintenance and management at our hospital.

    Science.gov (United States)

    Matsuda, Mitsumasa; Suzuki, Toshiyasu

    2016-06-01

    Lead aprons are worn by medical workers to reduce the effects of the radiation doses to which they are exposed during radiography and surgery performed with radioscopic apparatus. Regarding the management of such aprons, the Radiation Protection Section of the Japanese Society of Radiological Technology issued the "Guidelines for the Management of Lead Aprons" in 2000, and common management criteria have been set for all institutions. However, we found that the lead aprons used in operating rooms had not been closely inspected before 2014 in our hospital. Thus, we examined the extent of damage of such aprons in our operation room via computed tomography (CT) scout imaging, as well as visual and tactile inspections. Although no abnormality was detected upon visual and tactile inspections, CT images revealed that protective aprons used for 6 years or more had damaged internal radiation shields, thus risking radiation exposure. In response to these results, we fully realized the need to examine the date of the initial use of currently used lead aprons, to routinely perform visual and tactile inspections, and to regularly evaluate the extent of damage to the internal radiation shields via fluoroscopy in cooperation with the radiation management section. PMID:26842670

  10. Intelligent transportation systems in the planning and coordination of aircraft traffic at the airport apron

    OpenAIRE

    Pavlin, Stanislav; Roguljić, Slavko

    2015-01-01

    Airport aprons are areas for aircraft handling, parking and maintenance. According to international rules the number of positions at the apron has to be at least equal to the number of aircraft staying at any one time at the airport. The air traffic at Split Airport increased rapidly in the mid-90s when it became the UN logistics base for Bosnia and Herzegovina. There were nomeans nor free space for further expansion of the apron, so the traffic had to be reorganised and re-coordinated. Alter...

  11. The availability of appropriately fitting personal protective aprons and jackets for angiographic and interventional radiology personnel

    International Nuclear Information System (INIS)

    Purpose: This study explored the availability of personal protective equipment, lead or lead-free aprons or jackets, in angiographic and interventional radiology suites in the Republic of Ireland with a focus on the sizes available, appropriateness of fit and purchasing practices. Methods: All centres providing an angiographic or interventional radiology service in the Republic of Ireland were invited to participate with data being collected by means of a postal questionnaire exploring the above issues. Results: The mean number of aprons or jackets available across the centres who responded to the survey was 18.4 with the majority of these, 72%, being medium or large in size. Clinical specialists in three centres identified that there were insufficient aprons or jackets sized extra small or extra large within their departments and only one centre had a purchasing policy in place where individual staff were assigned a personal apron or jacket. Conclusion: Ill-fitting aprons or jackets will reduce the shielding provided to certain body regions by personal protective equipment. The use of over-sized aprons or jackets by staff is of particular concern based on the potential for inadvertent exposure to tissues where cancers may potentially be induced due to poor armhole fit. It is important to carefully consider purchasing practices and range of personal protective equipment sizes available in order to ensure that all staff receive the greatest possible protection from occupational radiation exposure

  12. 'Do lead rubber aprons pose an infection risk?'

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, Helen [Diagnostic Radiographer, Queen Elizabeth Hospital, Kings Lynn NHS Trust (United Kingdom); Strudwick, Ruth M., E-mail: r.strudwick@ucs.ac.u [School of Health, Science and Social Care, University Campus Suffolk, IP4 1QJ (United Kingdom)

    2010-11-15

    This study was carried out in order to establish whether infection control measures were being undertaken sufficiently on lead rubber aprons within a diagnostic imaging department in the east of England. This study involved the swabbing of a sample of 15 lead rubber aprons used within different areas of the department. Swabs were taken from the area on the underside of the shoulders and from the front of the apron. Each apron was firstly swabbed to determine the current level of microorganism contamination (determination of baseline data) and then again after recommended cleaning with detergent and water (the production of a standard). Comparisons were then made between the number of microorganisms' present (colony forming units/cm{sup 2}) pre and post-cleaning at each location. Additionally, post-cleaning data was compared for each location. All aprons were found to be contaminated with microorganisms, those identified were Coagulase-negative staphylococci, Staphylococcus aureus, Bacillus, Diphtheroids and some fungal spores. No Methicillin resistant strains of Staphylococcus aureus (MRSA) were identified. Recommended cleaning with detergent and water was found to significantly reduce the amount of microorganisms present (the detergent used was Hospec general purpose neutral liquid detergent). Comparisons of the sample sites found that the front of the apron had lower levels of microorganism contamination post-cleaning than the site at the underside of the shoulders. The results suggest that the lead rubber aprons were not being cleaned sufficiently which has infection control implications for the department. In order for cross contamination to be kept to a minimum an effective infection control policy needs to be employed and this should be to carry out regular cleaning with detergent and water which has been shown can significantly reduce contamination.

  13. Aqueous Alteration of Endeavour Crater Rim Apron Rocks

    Science.gov (United States)

    Ming, D. W.; Mittlefehldt, D. W.; Gellert, R.; Clark, B. C.; Morris, R. V.; Yen, A. S.; Arvidson, R. E.; Crumpler, L. S.; Farrand, W. H.; Grant, J. A., III; Jolliff, B. L.; Parker, T. J.; Peretyazhko, T.

    2014-12-01

    Mars Exploration Rover Opportunity is exploring Noachian age rocks of the rim of 22 km diameter Endeavour crater. Overlying the pre-impact lithologies and rim breccias is a thin apron of fine-grained sediments, the Grasberg fm, forming annuli on the lower slopes of rim segments. Hesperian Burns fm sandstones overly the Grasberg fm. Grasberg rocks have major element compositions that are distinct from Burns fm sandstones, especially when comparing interior compositions exposed by the Rock Abrasion Tool. Grasberg rocks are also different from Endeavour rim breccias, but have general compositional similarities to them. Grasberg sediments are plausibly fine-grained materials derived from the impact breccias. Veins of CaSO4 transect Grasberg fm rocks demonstrating post-formation aqueous alteration. Minor/trace elements show variations consistent with mobilization by aqueous fluids. Grasberg fm rocks have low Mn and high Fe/Mn ratios compared to the other lithologies. Manganese likely was mobilized and removed from the Grasberg host rock by redox reactions. We posit that Fe2+ from acidic solutions associated with formation of the Burns sulfate-rich sandstones acted as an electron donor to reduce more oxidized Mn to Mn2+. The Fe contents of Grasberg rocks are slightly higher than in other rocks suggesting precipitation of Fe phases in Grasberg materials. Pancam spectra show that Grasberg rocks have a higher fraction of ferric oxide minerals than other Endeavour rim rocks. Solutions transported Mn2+ into the Endeavour rim materials and oxidized and/or precipitated it in them. Grasberg has higher contents of the mobile elements K, Zn, Cl, and Br compared to the rim materials. Similar enrichments of mobile elements were measured by the Spirit APXS on West Spur and around Home Plate in Gusev crater. Enhancements in these elements are attributed to interactions of hydrothermal acidic fluids with the host rocks. Interactions of fluids with the Grasberg fm postdate the genesis

  14. The Alberta Pregnancy Outcomes and Nutrition (APrON) cohort study : rationale and methods

    NARCIS (Netherlands)

    Kaplan, Bonnie J.; Giesbrecht, Gerald F.; Leung, Brenda M. Y.; Field, Catherine J.; Dewey, Deborah; Bell, Rhonda C.; Manca, Donna P.; O'Beirne, Maeve; Johnston, David W.; Pop, Victor J.; Singhal, Nalini; Gagnon, Lisa; Bernier, Francois P.; Eliasziw, Misha; McCargar, Linda J.; Kooistra, Libbe; Farmer, Anna; Cantell, Marja; Goonewardene, Laki; Casey, Linda M.; Letourneau, Nicole; Martin, Jonathan W.

    2014-01-01

    The Alberta Pregnancy Outcomes and Nutrition (APrON) study is an ongoing prospective cohort study that recruits pregnant women early in pregnancy and, as of 2012, is following up their infants to 3 years of age. It has currently enrolled approximately 5000 Canadians (2000 pregnant women, their offsp

  15. Formation and mantling ages of lobate debris aprons on Mars: Insights from categorized crater counts

    Science.gov (United States)

    Berman, Daniel C.; Crown, David A.; Joseph, Emily C. S.

    2015-06-01

    Lobate debris aprons in the Martian mid-latitudes offer important insights into the history of the Martian climate and the role of volatiles in Martian geologic activity. Here we present the results of counts of small impact craters, categorized by morphology, on debris aprons in the Deuteronilus Mensae region and the area east of Hellas basin. Mars Reconnaissance Orbiter (MRO) ConTeXt Camera (CTX) images were used to document crater populations on the apron surfaces. Each crater was assessed and categorized according to its morphological characteristics (fresh, degraded, or filled). Fresh and most degraded craters likely superpose recent mantling deposits, whereas filled craters contain mantling deposits and thus indicate a minimum formation age for the apron (i.e., the age since stabilization of the debris apron surface following some modification but prior to mantling). Size-frequency distributions (SFDs) were compiled using established methodologies and plotted to assess their fit to the isochrons. The range or ranges in crater diameter over which each distribution paralleled the isochrons was determined by visual inspection, and general age constraints were noted from SFDs for all craters on a given surface and from each morphological class. The diameter range of each SFD segment observed to parallel an isochron was then input into the Craterstats2 analysis tool to calculate specific age estimates. The aprons were assessed both individually and as regional populations, which improved interpretation of the results and demonstrated the value and limitations of both approaches. The categorized counts reveal three groups of ages: (a) filled impact craters at larger diameters (>~500 m) typically show the oldest ages, between ~300 Ma and 1 Ga, (b) smaller diameter filled and degraded craters reveal ages of resurfacing events between ~10 Ma and 300 Ma, and (c) fresh crater populations (<~100 m diameter) indicate mantling deposits of less than ~10 Ma in age. These

  16. Guidance on the use of protective lead aprons in medical radiology protection efficiency and correction factors for personal dosimetry

    International Nuclear Information System (INIS)

    Workers in clinical radiology wear lead aprons when standing in the vicinity of a patient being exposed to x-rays. A lead apron protects the person's trunk against radiation scattered rom the patient. Our research is focused on two main issues: 1. How much protection does a lead apron provide, and what are the main factors that determine the protection efficiency 2. How can measured badge dose be translated into a realistic estimate of the effective dose, and how does this depend on dosemeter placement Using a model for x-ray shielding and dosimetry we calculated equivalent organ doses and personal depth dose HP(10) for various exposure conditions, x-ray energies and types of aprons that occur in clinical practice. We concluded that apron model and fit are often more important than lead thickness. In others, increasing lead thickness of a badly chosen apron will not provide better protection. For many fluoroscopy applications an apron of good model and fit need not be thicker than 0.5 mm of lead (equivalent). In case of intensive and frequent interventional work lead we advise higher lead thickness (0.35 mm), and preferably additional neck shielding for protection of the oesophagus and thyroid. A well chosen lead apron reduces effective dose by 75%up to 90%. We also concluded that the dosemeter badge should always be worn outside the apron, at mid front of collar or chest. In our view this dosemeter position enables reliable evaluation of effective dose from badge readings. As a standard practice we recommend translating measured badge dose to effective dose by dividing by a factor of five, provide that the worker wears a suitable lead apron. Finally, some research was done on the subject of the protective effect of lead aprons for the uterus, and the relation of uterus dose and badge dose. Use of a lead apron is found to reduce uterus dose by a factor of 5 to 10. Our study shows that in case of worker pregnancy, exposure of the unborn child may de adequately

  17. The leaded apron revisited: does it reduce gonadal radiation dose in dental radiology

    Energy Technology Data Exchange (ETDEWEB)

    Wood, R.E.; Harris, A.M.; van der Merwe, E.J.; Nortje, C.J. (Ontario Cancer Institute, Princess Margaret Hospital, Toronto (Canada))

    1991-05-01

    A tissue-equivalent anthropomorphic human phantom was used with a lithium fluoride thermoluminescent dosimetry system to evaluate the radiation absorbed dose to the ovarian and testicular region during dental radiologic procedures. Measurements were made with and without personal lead shielding devices consisting of thyroid collar and apron of 0.25 mm lead thickness equivalence. The radiation absorbed dose with or without lead shielding did not differ significantly from control dosimeters in vertex occlusal and periapical views (p greater than 0.05). Personal lead shielding devices did reduce gonadal dose in the case of accidental exposure (p less than 0.05). A leaded apron of 0.25 mm lead thickness equivalent was permeable to radiation in direct exposure testing.

  18. Apron layout design and flight-to-gate assignment at Lanseria International airport

    Directory of Open Access Journals (Sweden)

    Leonard, T.

    2013-05-01

    Full Text Available Air traffic is continuously increasing and more efficient air transport systems are required to handle the air travel demand. The study investigates the expansion of Lanseria International Airport in Gauteng, South Africa. Expansion of Lanseria requires a study of the airport apron layout to ensure efficient passenger-aircraft flow as well as the efficient flow of aircraft to and from the airport. The candidate layout designs are based on the layout concept of the Hartsfield-Jackson Atlanta International Airport in Atlanta, USA. In the study, different airport apron layouts were compared, including the existing layout of Atlanta Airport, via a simulation model of each. Designs based mainly on passenger transfer distance between the terminal building and aircraft were evaluated. The cross-entropy method was used to develop a generic flight-to-gate assignment program that minimises passenger transfer distances.

  19. The leaded apron revisited: does it reduce gonadal radiation dose in dental radiology

    International Nuclear Information System (INIS)

    A tissue-equivalent anthropomorphic human phantom was used with a lithium fluoride thermoluminescent dosimetry system to evaluate the radiation absorbed dose to the ovarian and testicular region during dental radiologic procedures. Measurements were made with and without personal lead shielding devices consisting of thyroid collar and apron of 0.25 mm lead thickness equivalence. The radiation absorbed dose with or without lead shielding did not differ significantly from control dosimeters in vertex occlusal and periapical views (p greater than 0.05). Personal lead shielding devices did reduce gonadal dose in the case of accidental exposure (p less than 0.05). A leaded apron of 0.25 mm lead thickness equivalent was permeable to radiation in direct exposure testing

  20. SU-E-I-56: Diagnostic Lead Apron Radiation Exposure Comparison Between Manufacture-Stated and Measurements

    International Nuclear Information System (INIS)

    Purpose: Several vendors of diagnostic lead apron used routinely in radiology/fluoroscopy claim to manufacture 0.5 mm lead equivalent shielding. The purpose of this investigation was to address the concern of the weight of lead aprons versus the radiation protection they provide. Methods: Seven diagnostic lead aprons were measured and compared for their radiation transmission and attenuation characteristics. The measurements were performed on a Philips Integris. Two settings were used, normal (76 kVp, 14.3 mA) and high (110 kVp, 12.3 mA) to represent typical patient and large patient thickness. Plastic water was placed on the table to represent patient scatter. A Capintec PM-500 ion chamber was placed at approximate chest height where hospital personnel would stand. An uncovered, i.e. lead-unhindered, ion chamber reading was taken to establish the baseline reading of an unprotected personnel. The ion chamber was then wrapped with 0.5mm 99.9% pure Pb material to establish the measurement reading when a diagnostic lead apron attenuates as adequately as 0.5mm Pb. The lead aprons were measured one at a time with the ion chamber fully covered and enclosed within the aprons. Results: On Normal fluoroscopy setting, the 0.5mm pure Pb showed a transmission of 0.4%. No aprons showed a transmission value as low as 0.5mm Pb. The lowest transmission value measured from the aprons was 2.0%, having a 1.5% higher transmission than pure lead. On High fluoroscopy setting, the lowest apron transmission measurement was at 2.8%, which was comparable to the 0.5mm pure Pb which gave a transmission of 3.0%. Conclusion: At Normal fluoroscopy setting, the 0.5mm Pb provided an attenuation that could not be matched by any apron measured. At High fluoroscopy setting, only one apron exhibited comparable transmission values as 0.5mm pure Pb

  1. Apron layout design and flight-to-gate assignment at Lanseria International airport

    OpenAIRE

    Leonard, T.; J. Bekker

    2013-01-01

    Air traffic is continuously increasing and more efficient air transport systems are required to handle the air travel demand. The study investigates the expansion of Lanseria International Airport in Gauteng, South Africa. Expansion of Lanseria requires a study of the airport apron layout to ensure efficient passenger-aircraft flow as well as the efficient flow of aircraft to and from the airport. The candidate layout designs are based on the layout concept of the Hartsfield-Jackson Atlanta I...

  2. Comparison of seismic reflection data to a synthetic seismogram in a volcanic apron at Site 953

    OpenAIRE

    Funck, Thomas; Lykke-Andersen, H.

    1998-01-01

    The volcanic apron of Gran Canaria at Site 953 is characterized by numerous, closely spaced reflectors, allowing a highresolution stratigraphic correlation. The calibration of the presite survey seismic data (during the Meteor Cruise 24) with regard to the lithology and stratigraphy found at the drill site was achieved by computing a synthetic seismogram serving as the link between seismic and borehole data. Because logging data were available for only 53% of the hole, velocity and d...

  3. Experimental Study of the Scour Regimes Downstream of an Apron for Intermediate Tailwater Depth Conditions

    Directory of Open Access Journals (Sweden)

    Paolo Espa

    2014-01-01

    Full Text Available The local scour of a non-cohesive bed due to a 2-D submerged horizontal jet is investigated experimentally in presence of a protection apron. Previous researches conducted without protection apron demonstrate that, when the tailwater depth is either deep or shallow, the equilibrium state characteristics of the scoured bed profile are mainly a function of the densimetric Froude number. However, when the submergence is between these two extremes, at fixed Froude number, three different scour regimes are possible. For relatively shallow tailwater depths, the jet mainstream directs towards the free surface (surface jet scouring regime, determining shallow and elongated scour profiles. For relatively large tailwater depths, the jet remains attached to the channel bottom (bed jet scouring regime, leading to deeper and shorter scour profiles. For intermediate conditions, the flicking of the jet between the erodible bed and the water free-surface is possible. When this instability occurs, the shape of the scour hole rapidly changes as a response of the jet mainstream position (bed-surface jet scouring regime. This paper aims to give an experimental description of the three mentioned regimes when a protection apron partly reduces the action of the flow on the loose bed. Scour hole profile evolution and velocity profile measurements obtained by LDA and ADV velocimetry are discussed.

  4. Control of downy mildew in sunflower with a new metalaxyl formulation apron XL-35 E.S.

    OpenAIRE

    Shirshikar S.P.

    2005-01-01

    Sunflower (Hellanthus annuus L) is susceptible lo diseases of various kinds Downy mildew is a destructive disease in many sunflower-growing countries. The disease is mainly seed-transmitted in nature. Hence, in the period 2000-2003. a new emulsion form of metalaxyl fungicide. Apron XL-35 E.S., was evaluated for its efficacy as seed dressing in I he management of sunflower downy mildew disease at Oilseeds Research Station. Latur (M.S). The three years of experimentation revealed that Apron XL-...

  5. Fabrication of indigenous lead-free low cost bilayer radiation protective apron and dosimetric analysis for effective shielding

    International Nuclear Information System (INIS)

    Protective aprons play a key role in the radiation protection of personnel in radiology departments. They are worn in examination rooms during radiological examinations and their specific function is to provide shielding against secondary radiation. Practically, they are used for a variety of diagnostic imaging procedures including angiography, fluoroscopy, mobiles and theatre, and are designed to shield approximately 75% of radiosensitive red bone marrow. For many years, the protective aprons play a key role in the radiation protection of personnel in imaging departments was made of lead. However, lead garments must be treated as hazardous waste for disposal and are heavy, causing back strain and other orthopedic problems for those who must wear them for long periods of time. They are worn in examination rooms during radiological examinations and their specific function is to provide shielding against secondary radiation. Originally, protective aprons consisted of lead-impregnated vinyl or rubber with a shielding equivalent given in millimetres of lead. The main purpose of this study was to fabricate light weight low cost non lead based bilayered radiation protective aprons

  6. Physical analysis of the shielding capacity for a lightweight apron designed for shielding low intensity scattering X-rays

    Science.gov (United States)

    Kim, Seon Chil; Choi, Jeong Ryeol; Jeon, Byeong Kyou

    2016-07-01

    The purpose of this paper is to develop a lightweight apron that will be used for shielding low intensity radiation in medical imaging radiography room and to apply it to a custom-made effective shielding. The quality of existing aprons made for protecting our bodies from direct radiation are improved so that they are suitable for scattered X-rays. Textiles that prevent bodies from radiation are made by combining barium sulfate and liquid silicon. These materials have the function of shielding radiation in a manner like lead. Three kinds of textiles are produced. The thicknesses of each textile are 0.15 mm, 0.21 mm, and 0.29 mm and the corresponding lead equivalents are 0.039 mmPb, 0.095 mmPb, 0.22 mmPb for each. The rate of shielding space scattering rays are 80% from the distance of 0.5 m, 86% from 1.0 m, and 97% from 1.5 m. If we intend to approach with the purpose of shielding scattering X-rays and low intensity radiations, it is possible to reduce the weight of the apron to be 1/5 compared to that of the existing lead aprons whose weight is typically more than 4 kg. We confirm, therefore, that it is possible to produce lightweight aprons that are used for the purpose of shielding low dose radiations.

  7. The Marquesas archipelagic apron: Seismic stratigraphy and implications for volcano growth, mass wasting, and crustal underplating

    Science.gov (United States)

    Wolfe, Cecily; McNutt, Marcia K.; Detrick, Robert S.

    1994-07-01

    Multichannel seismic lines, sonobuoy and gravity data across the Marquesas Islands are used to study volcano growth, island mass wasting, and crustal underplating at island chains with overfilled moats. The Marquesas bathymetry reflects the changing thickness of the sedimentary infill rather than the basement topography. The moat contains two major regions of differing seismic stratigraphy: (1) the moat edges, where a unit of continuous layered reflectors is present containing minor lenses of chaotic diffractors and, (2) the central moat, where the deep moat basins are overfilled by an acoustically opaque unit of discontinuous reflectors of up to 2 km thickness, in places capped by a ponded unit. Plate flexure models require broad underplating of the crust by low-density (crustal?) material at the Marquesas Islands to explain the depth to volcanic basement and gravity observations. The seismic velocities and seismic stratigraphy, as well as the general structure of the islands and surrounding seafloor, indicate the apron is mostly debris from island mass wasting. Reflectors of the outermost moat generally onlap the flexural arch in the lower section and offlap and overfill it in the upper section. In the central moat, reflectors change shape from concave up in the lower section to convex in the upper section. Three-dimensional diffusion models of sedimentaion, which incorporate a time-dependent seafloor deflection from progressive island loading and vary sediment influx as islands are formed and mass waste, suggest that three main factors make the moat stratigraphy at the Marquesas different from Hawaii: (1) the Marquesas moat is overfilled, while the Hawaiian moat is underfilled, (2) sediment diffusivities are lower at the Marquesas,and (3) the Marquesas islands are separated by deep sedimentary basins, in contrast to Hawaii, where islands are separated by a shallow ridge.

  8. Experimental determination of foetal doses received during conventional X rays explorations of troncus. Influence of the lead apron

    International Nuclear Information System (INIS)

    The aim of this paper is to assess the real doses received by pregnant women during some X rays conventional explorations of thorax and abdomen. The procedure that has been used is the measurement of doses by the use of thermoluminescent dosimeters located on the uterus position of a Random Phantom, and simulating different conventional X rays explorations. The results of such measurements are compared with other data published in ICRP 34, which were our reference. We have obtained smaller doses with the measurements than those derived from ICRP 34. The causes of these differences are analysed. The influence of the use of lead apron to protect abdomen during thorax examination is also analysed, computing the real value of this protection. We conclude that it seems interesting to obtain measurements of theses doses with our own equipment and techniques, because it offers a more realistic approximation to real doses received by patients. (author)

  9. An evaluation of the shielding effectiveness of lead aprons used in clinics for protection against ionising radiation from novel radioisotopes.

    Science.gov (United States)

    Deb, Pradip; Jamison, Robert; Mong, Lisa; U, Paul

    2015-07-01

    The purpose of this study is to evaluate the effectiveness of personal radiation shields currently worn in hospital and other diagnostic environments. This study was performed with four different radioisotopes; (18)F, (99m)Tc, (124)I and (131)I. (18)F results showed a decrease in dose with 0.5-mm Pb shielding but the reduction provided does not warrant its use clinically. (124)I testing demonstrated that dose enhancement can occur in greater shield thicknesses. PET isotope (124)I can be adequately shielded using 0.25-mm Pb equivalent aprons but any higher thickness increase the wearer's dose. As a result more shielding does not always equal more protection. The (131)I test showed that no dose reduction occurred, even when tested with up to 1.25-mm Pb equivalent shielding. Novel radioisotopes being used in the laboratory and clinic should be individually tested as each requires specific shielding testing. PMID:25848112

  10. Inteligentni transportni sistemi pri načrtovanju in usklajevanju gibanja in parkiranja letal na ploščadi letališča: Intelligent transportation systems in the planning and coordination of aircraft traffic at the airport apron:

    OpenAIRE

    Pavlin, Stanislav; Roguljić, Slavko

    2004-01-01

    Airport aprons are areas for aircraft handling, parking and maintenance. According to international rules the number of positions at the apron has to be at least equal to the number of aircraft staying at any one time at the airport. The air traffic at Split Airport increased rapidly in the mid-90s when it became the UN logistics base for Bosnia and Herzegovina. There were nomeans nor free space for further expansion of the apron, so the traffic had to be reorganised and re-coordinated. Alter...

  11. A look at one of the world`s largest apron feeder drives - Alberta Oil Sands Project

    Energy Technology Data Exchange (ETDEWEB)

    Persson, O. [Hagglunds Drives Canada Inc., Vancouver, BC (Canada)

    1999-10-01

    Various types of equipment to transport tar sands to processing plants are discussed, with special attention to the advantages of hydraulic direct drives over conventional electro-mechanical drives. A hydraulic direct drive such as the Hagglund Drive has exceptional starting torque capacity due to the high torque capability of the hydraulic motor. As such, it can be particularly useful in applications where shock loads occur with some frequency, or where many starts and stops are needed. Application of the Hagglund drive to power one of the world`s largest apron feeders in the Alberta Oil Sands is described as an illustration of the exceptional reliability, productivity and performance of this equipment. It has about one five-hundredth of the inertia of an equivalent high speed drive with gear reducer, a feature which is particularly significant in the case of feeders which are known to suffer much downtime due to chain related problems. These types of drives have also been used to great advantage in the process industries like pulp and paper, chemical, rubber and plastics, recycling and steel. 1 tab., 1 fig.

  12. A look at one of the world's largest apron feeder drives - Alberta Oil Sands Project

    Energy Technology Data Exchange (ETDEWEB)

    Persson, O. (Hagglunds Drives Canada Inc., Vancouver, BC (Canada))

    1999-01-01

    Various types of equipment to transport tar sands to processing plants are discussed, with special attention to the advantages of hydraulic direct drives over conventional electro-mechanical drives. A hydraulic direct drive such as the Hagglund Drive has exceptional starting torque capacity due to the high torque capability of the hydraulic motor. As such, it can be particularly useful in applications where shock loads occur with some frequency, or where many starts and stops are needed. Application of the Hagglund drive to power one of the world's largest apron feeders in the Alberta Oil Sands is described as an illustration of the exceptional reliability, productivity and performance of this equipment. It has about one five-hundredth of the inertia of an equivalent high speed drive with gear reducer, a feature which is particularly significant in the case of feeders which are known to suffer much downtime due to chain related problems. These types of drives have also been used to great advantage in the process industries like pulp and paper, chemical, rubber and plastics, recycling and steel. 1 tab., 1 fig.

  13. Efficacy of aprons equivalent to 0.5 mm of lead in PET procedures using the Monte Carlo method; Eficacia de aventais equivalentes a 0,5 mm de chumbo em procedimentos PET usando o metodo Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, R.B.; Amaral, A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Campos, L., E-mail: amaral@ufpe.br [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil). Dept. de Fisica

    2012-07-01

    In positron emission tomography (PET), health staff is exposed to 511-keV photons, which is a result of the positron annihilation process. This energy is about four times greater than the 140 keV commonly found in studies based on single photon emission computed tomography (SPECT). Besides this different level of energy, 0.5 mm lead-equivalent aprons have being used either in SPECT or PET procedures. In this context, this work was designed for evaluating the effectiveness of such aprons in individual radioprotection of health professionals involved in positron emission tomography. For this, by using MCNP4C-based Monte Carlo simulations, the average energy delivered per particle to the regions corresponding to operational quantities Hp(10) and Hp(0.07) were calculated for two conditions of individual exposures: wearing and not wearing a 0.05 mm lead-equivalent apron. The results obtained pointed out that Hp(10) has similar value in both situations. On the other hand, for the region corresponding to Hp(0.07), wearing this lead apron will improve this dose in about 26%. On the basis of this work, 0.5 mm lead equivalent aprons do not offer adequate protection for medical staff working on positron emission tomography. (author)

  14. A Comparison and Analog-Based Analysis of Sinuous Channels on the Rift Aprons of Ascraeus Mons and Pavonis Mons Volcanoes, Mars

    Science.gov (United States)

    Collins, A.; de Wet, A.; Bleacher, J.; Schierl, Z.; Schwans, B.

    2012-01-01

    The origin of sinuous channels on the flanks of the Tharsis volcanoes on Mars is debated among planetary scientists. Some argue a volcanic genesis [1] while others have suggested a fluvial basis [2-4]. The majority of the studies thus far have focused on channels on the rift apron of Ascraeus Mons. Here, however, we broadly examine the channels on the rift apron of Pavonis Mons and compare them with those studied channels around Ascraeus. We compare the morphologies of features from both of these volcanoes with similar features of known volcanic origin on the island of Hawai i. We show that the morphologies between these two volcanoes in the Tharsis province are very similar and were likely formed by comparable processes, as previous authors have suggested [5]. We show that, although the morphologies of many of the channels around these volcanoes show some parallels to terrestrial fluvial systems, these morphologies can also be formed by volcanic processes. The context of these features suggests that volcanic processes were the more likely cause of these channels.

  15. Boulder aprons indicate long-term gradual and non-catastrophic evolution of cliffed escarpments, Stołowe Mts, Poland

    Science.gov (United States)

    Duszyński, Filip; Migoń, Piotr

    2015-12-01

    Caprock-crowned escarpments are characteristic geomorphic features of the sandstone tableland of the Stołowe Mountains (SW Poland). Their mid- and lower slopes truncate weaker sedimentary formations but are littered with sandstone boulders of various size, often more than 5 m long, which form nearly continuous aprons. A model of escarpment retreat by rock fall has been widely accepted in literature but in the Stołowe Mountains it has never been tested against field evidence; in addition no rock fall events except one minor fall in 1921 have been recorded in historical times. In this paper we erected five hypotheses of how escarpments may have evolved through time to result in widespread boulder presence on the slopes. Mapping boulder extent and slope morphology, run-out distance simulations using Conefall software, and rock strength determinations using the Schmidt hammer carried out on boulders along eight representative slope profiles provide data about characteristics of the boulder covers. Systematic decrease in intact rock strength with an increasing distance from the sandstone cliffs suggests that the boulder aprons are diachronic and record long-term retreat of escarpments. There exists no conclusive evidence of widespread boulder downslope movement, although in a few localities shallow landslides have rafted boulders far away from the cliff lines. Modelling exercise shows that the actual extent of boulders is 2-3 times bigger than suggested by Conefall predictions. These findings, coupled with observations along the cliff lines themselves, lead us to propose a model of free face in situ disintegration as the most likely hypothesis to explain block detachment and release from rock faces. As cliff lines recede and the slope surface below is lowered, remnant boulders occupy a position increasingly further away from escarpment rims, but experience little actual movement. This model complements the existing models of tableland evolution which tend to emphasize

  16. UTILIZAÇÃO DO AVENTAL COMO AUXILIAR NO PÓS-OPERATÓRIO DA ACROBUSTITE OU ACROBUSTITE-FIMOSE THE USE OF AN APRON AS AID FOR ACROBUSTITIS OR ACROBUSTITIS-PHIMOSIS POSTOPERATIVE

    Directory of Open Access Journals (Sweden)

    Luiz Antônio Franco da Silva

    2007-09-01

    Full Text Available

    Foi utilizado um avental protetor em 15 bovinos, reprodutores, submetidos a operação de acrobustite ou acrobustite-fimose. O acessório mostrou-se eficiente, prático e diminuiu as possibilidades de complicações durante o pós-operatório.

    PALAVRAS-CHAVE: Bovino; prepúcio; cirurgia.

    A protective apron was used in 15 bulls submitted to acrobustitis and acrobustitis-phimosis surgery. The apron was efficient to reduce complication on postoperative.

    KEY-WORDS: Bovine; preputium; surgery.

  17. Evaluation of the attenuation of the lead aprons with different lead equivalences for use in radiology services; Avaliacao da atenuacao de aventais plumbiferos com diferentes equivalencias de chumbo para uso em servicos de radiologia

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel, Juliana, E-mail: juliana.pimentel@pucrs.br [Hospital Sao Lucas (HSL/PUCRS), Porto Alegre, RS (Brazil); Borgonhi, William Mello, E-mail: borgonhi@gmail.com [Instituto Pro Universidade Canoense (IPUC), Canoas, RS (Brazil); Vanni, Stefania, E-mail: stevannni87@gmail.com [Assessoria em Fisica Medica (AFIM), Porto Alegre, RS (Brazil)

    2014-07-01

    This work has the aim to evaluate the attenuation of personal protective gear of lead rubber with equivalence of 0.25 and 0.50 mmPb, the scattered radiation. It was used as a radiation emitter, a x-ray equipment brand GE® Model XR6000 with maximum voltage of 150 kVp, the maximum electric current of 630 mA. How spreader object was used a cylindrical acrylic simulator with measures 32 cm by 15 cm. To collect the measurements was used the ionizing chambers Fluke Biomedical® Victoreen® model 451B-DE-SI. The individual protective clothing evaluated were two rubber aprons with equivalence of 0.25 and 0.50 mmPb. To perform the experiment the simulator equipment was placed on the table aligned with the primary beam with focus-film distance of one meter. Were used as exposure parameters 85 kVp, 80 mA and 2.5 sec. Recordings were carried out at distances from 50 to 250 cm, ranging from 25 to 25 cm. For each distance were made four measures in the air and four measures with each VPI in front of the meter, checking the equivalent dose rate and tabling the values obtained. For aprons with equivalence 0,25mmPb average attenuation obtained was 94.05%, with standard deviation of 1.36. As for the aprons with 0,50mmPb the affected attenuation was 97.6%, with deviation of 0.75. From the results of this assessment, it is evident the importance of radiological protective clothing in the routines of individuals occupationally exposed to X-ray.

  18. 车床溜板箱防撞装置的改进设计与应用%The design and application of the improvement of the anti-collision device in the lathe apron

    Institute of Scientific and Technical Information of China (English)

    盖立武; 王成; 吴婷婷; 赵亮

    2013-01-01

    The traditional anti-collision device in the lathe apron can only prevent the apron from vertically colliding onto the chuck or tail stock in some specific situation. The improved device is composed of a set of guide rods and five processing button located differently. The innovated device can not only have the previous function, but also keep the small feeding carriage or blade carrier motor from bumping onto the tail stock vertically and horizontally. So the new anti-collision device can be in functionality of protection, regardless of the any position of the tail stock in the guide way. And the real applications demonstrate ; compared with the traditional one, the initiated device expands the scale of security protection and shortens the time of regulation.%针对传统的车床溜板箱防撞装置只能防止溜板箱在某一特定情况下沿纵向与卡盘或尾座的碰撞,设计了一套由导向杆和5个位于溜板箱上不同位置的行程开关所组成的防撞装置.此防撞装置既可以防止溜板箱在纵向与卡盘或尾座的碰撞,又可防止小滑板(或刀架电动机)在纵向和横向上与尾座的碰撞,因此尾座不论在导轨的任何位置上,此防撞装置均能起到保护作用.实际运用显示:改进后的车床溜板箱防撞装置与以前的防撞装置相比较,安全防护范围扩大了,调整时间缩短了.

  19. Analysis and design for structural stress of T320 floor boring apron%T320落地镗溜板箱结构应力分析与设计

    Institute of Scientific and Technical Information of China (English)

    杨顺田; 杨天雄; 彭美武

    2012-01-01

    In order to solve rough machining problem of the above 300 tons large and super large components of mill,large,ultra-heavy boring and milling machine is required in urgentTherefore,T320 digital display type boring machine was developed in this contextThrough studying the machine column, the thermal equilibrium system as well as the inertia parameters matching and the spindle apron structure, the machine column was designed particularly into a closed cross-section of welded structures with the shock filler being injected into,which may change the traditional casting structural design;Then through cloud analysis on the contact state of the apron with columns and track,the structure was optimized;Temperature compensation system was adopted to ensure the heat balance of bearing system,and meet the extra requirements for rough machining large pieces ,which main design highlights the characteristics of large, heavy machine design.%为了解决300t以上特大型焊接件、特大型轧机的粗加工难题,急需大型、超重型落地铣镗床.T320数显落地镗就是在这种背景下研制的.通过对机床立柱、热平衡系统、惯量参数匹配与主轴溜板箱结构等内容的研究,特别是将机床立柱设计成封闭式截面的焊接结构,并在其结构内注入防震填料,改变了传统的铸件结构设计;再通过对溜板箱与立柱和轨道的接触状态云分析,对其结构进行优化;采用温度补偿系统保证轴承热系统平衡,满足了特大型件的粗加工要求,其主要设计思想彰显出大型、超重型机床设计的特色.

  20. Experimental study on mechanism of energy dissipation and erosion control of aprons for sluices%闸下海漫柔性加糙体消能防冲机理试验

    Institute of Scientific and Technical Information of China (English)

    史国庆; 文恒; 牟献友

    2011-01-01

    Based on the laboratory hydraulic model tests, the distribution of three-dimensional velocity after raising the roughness of the aprons by means of scrap tires was measured. The results show that the bottom velocity of water obviously decreases and the average velocity of the whole cross-section is approximately equal. With the increase of the tires, the average turbulence intensity and the additional shear stress and the fluid mixing increase so as to improve the efficiency of energy dissipation.%通过室内水工模型试验,量测了采用废旧轮胎加糙后三维流速的分布.结果表明:加糙后近底流速明显降低,但整个断面的平均流速近似相等;随着轮胎排数的增加,水流紊流强度平均值增大,附加切应力增大,流体质点间相互混掺的情况加剧,从而使消能效率得以提高.

  1. Surface Subsidence Control of a Tianjin Metro Shield Tunnel Passing under a Parking Apron%天津地铁盾构隧道下穿停机坪施工地表沉降控制

    Institute of Scientific and Technical Information of China (English)

    赵敏; 徐增伟

    2016-01-01

    以天津地铁二号线盾构隧道下穿滨海国际机场停机坪工程为对象,文章运用ANSYS软件对盾构掘进过程进行了数值模拟分析,分析了不同工况下的地层位移和地表沉降。模拟结果表明:在盾构的顶进作用下,地层位移的下沉最大值出现在隧道的拱顶处,隆起最大值出现在仰拱处,地表发生前隆后沉的现象;两条隧道同时开挖引起的地表沉降量大于右线隧道开挖60 m后再开挖左线隧道所引起的沉降量;在顶进压力0.2 MPa、注浆压力0.35 MPa时引起的地表沉降量约为5 mm,符合机场相关要求。根据模拟结果对盾构下穿停机坪掘进施工提出了控制措施,实测结果显示,地表沉降和隆起值在安全范围内,盾构隧道施工对停机坪的正常运营影响很小。%In this paper, based on a shield tunnel of Tianjin Metro line 2 passing beneath Binhai International Air⁃port, the ground displacement and surface subsidence are analyzed under different conditions by means of simulat⁃ing the shield excavation process through ANSYS software. Simulation results show that under the shield-jacking ef⁃fect, the maximum subsidence occurs at the crown and the maximum upheaval occurs at the invert of the tunnel, which first causes ground surface heaves and then subsides; the ground subsidence caused by simultaneous con⁃struction of two tunnel tubes is greater than that caused by constructing the left tube after the right tube has been ex⁃cavated 60 meters;in a scenario with 0.2 MPa jacking pressure and 0.35 MPa grouting pressure, the ground subsid⁃ence is about 5 mm, conforming to the requirements of airport operation. According to the simulation results, corre⁃sponding control measures for shield driving beneath an adjacent parking apron are put forward. The measured re⁃sults indicate that surface subsidence and heaving are controlled within the scope of safety limits, and shield tunnel

  2. Research on Cooperative Schedule for Container Terminal Apron Based on Firefly Algorithm%基于萤火虫算法的集装箱码头前沿协同调度研究

    Institute of Scientific and Technical Information of China (English)

    陈文

    2014-01-01

    This paper analyzes the operation resource assignment problem in container terminal apron. It proposes a joint schedule strategy for berth and quay crane under the mode of continuous berth layout,establishes a berth assignment mode according to the feature of location preference by container vessels,establishes the quay crane schedule strategy ac-cording to the constrains of expected departure time of the container vessels and their handling states,and makes the solu-tion to the joint schedule model by adopting the firefly optimal algorithm. Through simulation experiments,the schedule re-sults under berthing in order and different number of vessels are compared and analyzed. The results show that the coopera-tive schedule strategy and optimization algorithm are effective.%针对集装箱码头前沿作业资源调度问题,构建了连续泊位划分方式下的泊位和岸桥的联合调度策略。针对船舶具有偏好位置的属性,建立了泊位分配策略;根据船舶的期望离港时间约束和过程作业情况,建立了岸桥的调度策略;采用萤火虫优化算法对联合调度模型进行了求解,通过仿真实验,对顺序靠泊和不同船舶数量条件下调度结果进行了比较分析。实验结果显示用该算法求解联合调度问题是有效的。

  3. End-Pleistocene to Holocene paleoenvironmental record from piston corer samples and the challenge of stratigraphic correlation of playa sediment data with a connected alluvial apron from Damghan Basin, Iran

    Science.gov (United States)

    Büdel, Christian; Hoelzmann, Philipp; Wennrich, Volker; Majid Padashi, Sajed; Baumhauer, Roland

    2015-04-01

    The study yields a first characterization and correlation of the end-Pleistocene to Holocene sediment archive of playa and playa lake deposits in the Damghan Basin, northern Iran. The Basin sediments are deposited since Mio- and Pliocene, which is valid for the connected alluvial fans, too. These are covering the area between the playa and mountains and while prograding from the mountain ranges they deliver gravels and fine-sediments to the basins sink. The processes on the studied alluvial apron are described and dated already and can be explained in seven morphodynamic phases, which are linked to a general lake level high-stand in north-east Iran at about 8000-9000 years ago. If and how these phases are passed on from the alluvial record down to the playa sediment record is aim of this study. Today the salt pans margins are highly affected by salt tectonic drifting and access was suboptimal. Only here drilling could be performed through about 280 centimeters of salt-crust unfrequently intercalated with loamy layers. For yielding undisturbed playa sediment records sampling was performed with inliner-tubes deployed in a piston corer (Kullenberg type). Thus at two different drilling sites in summation seven cores could be taken, down to a maximum depth of 129 cm and 1000 cm. Back in Germany the cores had been opened and initially described, photographed and optically scanned with a core logger. Regarding future studies, the aim was a best possible comprehensive documentation of the cores. Therefore basically grainsize measurements (laser diffraction), multi element analyses (XRF, ICP-OES, titrimetry) and mineralogical measurements (XRD) had been deployed on samples taken from every single previously identified layer. Continuous elemental data was secured by use of a XRF-scanning core logger. The sedimentological description together with laboratory element analyses shows saline conditions in the first three meters coincide with general coarser grain sizes. The next

  4. THE APPLICATION OF MASSING HANDLING THEORY FOR EVALUATION OF THE APPLICATION OF WHARVES AND LOADING FACILITIES IN THE MARITIME PORT

    Directory of Open Access Journals (Sweden)

    Zbigniew Matuszak

    2016-09-01

    Full Text Available This work presents the general characteristics of the port system. It defines sets and functions describing the structure and work of the port. Moreover, it characterizes foundations of the massive handling theory. It provides basic literature information about selected processes and models of the massive handling theory. On the example of a transportation company serving the loading on ships in the port of Szczecin, it shows the loading method. The material loading onto ships was the sodium water glass. There are observation results of operation times comprising the data available to determine parameters of the massive handling theory. Operations covered in the analysis include: the arrival of the ship at the port’s road, waiting for enter the port, passing through the fairway, waiting for loading, loading, determination of the cargo’s weight, preparation of documents and waiting for leaving the port. It presents critical remarks about possibilities of using the data obtained to describe loading cargo on a ship with the use of elements of the massive handling theory.

  5. From loom to machine: Tibetan aprons and the configuration of place

    NARCIS (Netherlands)

    C.H. Harris

    2012-01-01

    In this paper I examine how objects become connected to place in complex and contradictory ways. Over the past ten to fi fteen years, rapid transformations in Chinese manufacturing and transportation networks have signifi cantly altered the production, marketing, and consumption of commodities made

  6. Apron strings of working mothers: Maternal employment and housework in cross-national perspective.

    Science.gov (United States)

    Treas, Judith; Tai, Tsui-O

    2012-07-01

    This paper asks whether maternal employment has a lasting influence on the division of household labor for married women and men. Employing multi-level models with 2002 ISSP survey data for 31 countries, we test the lagged accommodation hypothesis that a long societal history of maternal employment contributes to more egalitarian household arrangements. Our results find that living in a country with a legacy of high maternal employment is positively associated with housework task-sharing, even controlling for the personal socialization experience of growing up with a mother who worked for pay. In formerly socialist countries, however, there is less gender parity in housework than predicted by the high historical level of maternal employment. PMID:23017854

  7. Iron-Manganese Redox Reactions in Endeavour Crater Rim Apron Rocks

    Science.gov (United States)

    Ming, D. W.; Mittlefehldt, D. W.; Gellert, R.; Peretyazhko, T.; Clark, B. C.; Morris, R. V.; Yen, A. S.; Arvidson, R. E.; Crumpler, L. S.; Farrand, W. H.; Grant, J. A., III; Jolliff, B. L.; Parker, T. J.; Schroder, C.

    2015-01-01

    The Mars Exploration Rover Opportunity has been exploring Noachian age rocks and outcrops on the rim of the 22 km diameter Endeavour crater since August 2011. The Cape York area is a low-lying rim of Endeavour that contains 3 distinct lithologies: 1) the stratigraphically lowest Matijevic fm of pre-impact lithology, 2) Shoemaker fm of impact breccias, and 3) the stratigraphically highest rim lithology Grasberg fm of post-impact sediments that drape the lower slopes of the rim. The sulfate-rich sediment of the Burns fm lies unconformably over the Grasberg fm. Ca-sulfate veins were discovered in Grasberg fm sediments; the sulfates precipitated from aqueous fluids flowing upward through these materials. Opportunity investigated the chemistry and morphology of outcrops in the Matijevic fm that have Fe(sup 3+)-rich smectite detected by orbital signatures returned by CRISM on MRO. Matijevic fm also contains "boxwork" fractures with chemistry consistent with an Al-rich smectite and veins that appear to be rich in Ca-sulfate. More recently on Cape Tribulation, Opportunity has characterized two S-, Mg- and Mn-rich rich rocks overturned and fractured by the rover's wheels on Cook Haven. Those rocks have been dubbed "Pinnacle Island" and "Stuart Island" and will be referred to as the "Island" rocks. The objectives of this study are to characterize the Fe and Mn contents in the Cape York materials, including the two Island rocks, and to provide a model for Mn mobilization and precipitation. Detailed geochemistry of Endeavour rim rocks is presented in a companion paper. Geochemical trends and elemental associations were obtained from data returned by the Alpha Particle X-ray Spectrometer (APXS) on Opportunity.

  8. Structuring of Gender in Israeli Society through Children's Reading and Textbooks: Where Is Mom's Apron?

    Science.gov (United States)

    Shachar, Rina

    2012-01-01

    This study examines changes that have transpired in the reflection of gender structuring in children's books over several decades. The issue of gender in the education system, the structuring of gender stereotypes, and their influence on the distribution of roles between males and females in society are discussed. The study examines children's…

  9. Capricious, or tied to history’s apron strings? Floristic regions in north-west European brambles (Rubus subgenus Rubus, Rosaceae)

    NARCIS (Netherlands)

    Haveman, R.; Bijlsma, R.J.; Ronde, de I.; Schaminee, J.H.J.

    2016-01-01

    Aim To classify and describe distributional patterns in apomictic Rubus subgenus
    Rubus in north-west Europe and to characterize the major regions by
    statistically derived character species.
    Location North-western Europe, in particular Ireland, the United Kingdom,
    the Netherlands, Den

  10. UTILIZAÇÃO DO AVENTAL COMO AUXILIAR NO PÓS-OPERATÓRIO DA ACROBUSTITE OU ACROBUSTITE-FIMOSE THE USE OF AN APRON AS AID FOR ACROBUSTITIS OR ACROBUSTITIS-PHIMOSIS POSTOPERATIVE

    OpenAIRE

    Luiz Antônio Franco da Silva; Maria Clorinda Soares Fioravanti; Naida Cristina Borges; Mauro Inácio Carneiro; Carla Afonso da Silva

    2007-01-01

    Foi utilizado um avental protetor em 15 bovinos, reprodutores, submetidos a operação de acrobustite ou acrobustite-fimose. O acessório mostrou-se eficiente, prático e diminuiu as possibilidades de complicações durante o pós-operatório.

    PALAVRAS-CHAVE: Bovino; prepúcio; cirurgia.

  11. 77 FR 37043 - Notice of Agreements Filed

    Science.gov (United States)

    2012-06-20

    ... authorizes Wan Hai to charter slots to PIL in the trade from California to China. Agreement No.: 200163-004.... Gregory, Secretary. BILLING CODE 6730-01-P ... Wharves, Port of Houston Authority, Lake Charles Harbor and Terminal District, Manatee County...

  12. 46 CFR Sec. 3 - Terminal operating contract.

    Science.gov (United States)

    2010-10-01

    ... terminals; stowing and snugging cargo in the space on the terminal; issuing and receiving proper receipts... Facilities as used in this agreement means piers, wharves, warehouses, covered and/or open storage space... not discriminate against any employee or applicant for employment because of race, color,...

  13. 77 FR 14584 - Notice of Passenger Facility Charge (PFC) Approvals and Disapprovals

    Science.gov (United States)

    2012-03-12

    ... loader. Reconstruct a portion of the west terminal apron. Replace west terminal apron lights. Reconstruct a portion of the east terminal apron (approximately 18,256 square yards). Modify supplemental wind cones. Runway 8/26 pavement rejuvenation. Purchase snow removal equipment--high-speed snow plow....

  14. 78 FR 76389 - Notice of Passenger Facility Charge (PFC) Approvals and Disapprovals

    Science.gov (United States)

    2013-12-17

    ... operating at Southwest Florida International Airport (RSW). Determination: Approved. Based on information... vehicles and equipment. Extend and rehabilitate apron (airline). Demolish old passenger terminal...

  15. Personnel dosimetry in fluoroscopy

    International Nuclear Information System (INIS)

    Physicians who frequently perform fluoroscopic examinations are exposed to high intensity radiation fields and should use protective equipment such as lead aprons, thyroid shields and lead glasses. Standard individual dosimeters are worn under the lead apron in order to measure a dose that is representative of effective dose. However, large parts of the body are not protected by the apron (e.g. arms, head). Given a protection factor for the apron of about 100, an important irradiation of a body part not under the apron could go undetected. A study was conducted to analyse this situation by measuring dose using two dosimeters, one over-apron and one under-apron, for radiologists performing frequent fluoroscopic examinations. Measurements made over six-month period show that, indeed, the use of a single under-apron dosimeter is inadequate for personnel monitoring. Large doses to the head and arms are going undetected by this technique. A method for weighting the doses measured by under- and over-apron dosimeters to obtain a value better representative of the effective dose will be proposed. (authors)

  16. Personnel dosimetry in fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Baechler, S.; Gardon, M.; Bochud, F.; Sans-Merce, M.; Verdun, F.R. [University Institute for Radiation Physics, Lausanne (Switzerland); Trueb, Ph. [Federal Office of Public Health, Berne (Switzerland)

    2006-07-01

    Physicians who frequently perform fluoroscopic examinations are exposed to high intensity radiation fields and should use protective equipment such as lead aprons, thyroid shields and lead glasses. Standard individual dosimeters are worn under the lead apron in order to measure a dose that is representative of effective dose. However, large parts of the body are not protected by the apron (e.g. arms, head). Given a protection factor for the apron of about 100, an important irradiation of a body part not under the apron could go undetected. A study was conducted to analyse this situation by measuring dose using two dosimeters, one over-apron and one under-apron, for radiologists performing frequent fluoroscopic examinations. Measurements made over six-month period show that, indeed, the use of a single under-apron dosimeter is inadequate for personnel monitoring. Large doses to the head and arms are going undetected by this technique. A method for weighting the doses measured by under- and over-apron dosimeters to obtain a value better representative of the effective dose will be proposed. (authors)

  17. Individual monitoring of medical staff working in interventional radiology in Switzerland using double dosimetry

    International Nuclear Information System (INIS)

    Physicians who frequently perform fluoroscopic examinations are exposed to high intensity radiation fields. The exposure monitoring is performed with a regular personal dosimeter under the apron in order to estimate the effective dose. However, large parts of the body are not protected by the apron (e.g. arms, head). Therefore, it is recommended to wear a supplemental dosimeter over the apron to obtain a better representative estimate of the effective dose. The over-apron dosimeter can also be used to estimate the eye lens dose. The goal of this study was to investigate the relevance of double dosimetry in interventional radiology. First the calibration procedure of the dosimeters placed over the apron was tested. Then, results of double dosimetry during the last five years were analyzed. We found that the personal dose equivalent measured over a lead apron was underestimated by ∼20% to ∼40% for X-ray beam qualities used in radiology. Measurements made over five-year period confirm that the use of a single under-apron dosimeter is inadequate for personnel monitoring. Relatively high skin dose (>10 mSv/month) would have remained undetected without a second dosimeter placed on the apron.

  18. ESO at the IAU General Assembly

    Science.gov (United States)

    2003-09-01

    The 25th General Assembly of the International Astronomical Union was held in Sydney,Australia, from 13-24 July 2003. For two weeks the world of professional astronomy descended on Darling Harbour. In the early days it was used for receiving fresh produce and timber from Parramatta and the north coast, but with time had become a somewhat derelict dock area. Following massive redevelopment of the old wharves in the course of the 1980s, it now constitutes a spectacular example of contemporary urban renovation, with shopping malls, hotels, restaurants, museums and other leisure facilities, as well as the magnificent Sydney Convention and Exhibition Centre (SCEC).

  19. Bonneville Project: CFD of the Spillway Tailrace

    Energy Technology Data Exchange (ETDEWEB)

    Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.; Romero Gomez, Pedro DJ

    2012-11-19

    US Army Corps of Engineers, Portland District (CENWP) operates the Bonneville Lock and Dam Project on the Columbia River. High spill flows that occurred during 2011 moved a large volume of rock from downstream of the spillway apron to the stilling basin and apron. Although 400 cubic yards of rocks were removed from the stilling basin, there are still large volumes of rock downstream of the apron that could, under certain flow conditions, move upstream into the stilling basin. CENWP is investigating operational changes that could be implemented to minimize future movement of rock into the stilling basin. A key analysis tool to develop these operational changes is a computational fluid dynamics (CFD) model of the spillway. A free-surface CFD model of the Bonneville spillway tailrace was developed and applied for four flow scenarios. These scenarios looked at the impact of flow volume and flow distribution on tailrace hydraulics. The simulation results showed that areas of upstream flow existed near the river bed downstream of the apron, on the apron, and within the stilling basin for all flows. For spill flows of 300 kcfs, the cross-stream and downstream extent of the recirculation zones along Cascade and Bradford Island was very dependent on the spill pattern. The center-loaded pattern had much larger recirculation zones than the flat or bi-modal pattern. The lower flow (200 kcfs) with a flat pattern had a very large recirculation zone that extended half way across the channel near the river bed. A single flow scenario (300 kcfs of flow in a relatively flat spill pattern) was further interrogated using Lagrangian particle tracking. The tracked particles (with size and mass) showed the upstream movement of sediments onto the concrete apron and against the vertical wall between the apron and the stilling basin from seed locations downstream of the apron and on the apron.

  20. 身影(英文)

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Zhang Jing: Putting on a Cerise Apron to Make Noodles张静:系着水红色围裙的面馆老板If you roamed around the streets in the eastern suburbs of Xi'an, the capital city of Northwest China's Shaanxi Province, you'd see a small, but thriving, noodle restaurant and a smiling young woman with a cerise apron standing at the gate to greet each customer during peak hours. Her happy and confident smile and her cerise apron certainly make her

  1. Late Amazonian Glaciations in Utopia Planitia, Mars

    Science.gov (United States)

    Osinski, G. R.; Capitan, R. D.; Kerrigan, M.; Barry, N.; Blain, S.

    2012-03-01

    We present evidence from western Utopia Planitia, including lineated valley fill and lobate debris aprons, for widespread glaciations over a large expanse of the northern plains and dichotomy boundary during Late Amazonian times.

  2. 46 CFR 153.214 - Personnel emergency and safety equipment.

    Science.gov (United States)

    2010-10-01

    ... lifting an injured person from a pumproom or a cargo tank. (b) In addition to any similar equipment... minutes capacity each. (2) A set of overalls or large apron, boots, long sleeved gloves, and goggles,...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... ray (radiograph) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Imaging with ... or other positioning devices will be used to help you maintain the proper position. A lead apron ...

  4. Exposure of the orthopaedic surgeon to radiation

    International Nuclear Information System (INIS)

    We monitored the amount of radiation received by surgeons and assistants during surgery carried out with fluoroscopic assistance. The radiation was monitored with the use of MYDOSE MINIX PDM107 made by Aloka Co. Over a one year period from Aug 20, 1992 to Aug 19, 1993, a study was undertaken to evaluate exposure of the groin level to radiation with or without use of the lead apron during 106 operation (Group-1). In another group, radiation was monitored at the breast and groin level outside of the lead apron during 39 operations (Group-2). In Group-1, the average exposure per person during one year was 46.0 μSV and the average exposure for each procedure was 1.68 μSV. The use of the lead apron affirmed its protective value; the average radiation dose at the groin level out-side of the apron was 9.11 μSV, the measured dose beneath the apron 0.61 μSV. The average dose of exposure to the head, breast at groin level outside of the lead apron, were 7.68 μSV, 16.24 μSV, 32.04 μSV respectively. This study and review of the literature indicate that the total amount of radiation exposure during surgery done with fluoroscopic control remains well within maximum exposure limits. (author)

  5. Development of measurement method using TLD for workers occupation personally exposed to 125I seed source in the implant

    International Nuclear Information System (INIS)

    Objective: To explore the method for measuring and calculating both absorbed dose and effective dose received in organ and tissues of occupational workers by using TLDs for the implantation of 125I seed sources. Methods The experiments with 60Co γ-rays were carried out for the stability. A group of TLD chips was exposed to 125I seed sources to establish standard dose curve for air kerma. During the 125I seed implantation, the TLD chips were pasted to 13 locations like thyroid inside and outside the lead aprons worn by occupational workers to measure average absorbed dose and calculate the absorbed doses and effective to organs and tissues. Results: For 3 cases of prostate cancers with implantation of 125I seeds, the worker's organs and tissues received the absorbed dose 0.02 -3.80 μ Gy and effective dose 0.06- 1.81 μSv outside lead aprons and the highest absorbed dose 2.35 μ Gy and effective 0.02 μSv inside lead aprons, respectively, with more than 65.9% of rays shielded. For 3 cases of brain cancers with implantation of 125I seeds, the workers received the absorbed dose 0.23 - 11.31 μGy and effective dose 0.88-4.07 μSv outside lead aprons and the highest absorbed dose 2.22 μ Gy and effective dose 0.09 μSv inside lead aprons, respectively, with more than 54.5% of rays shielded. For 3 cases of lung cancers with implantation of 125I seeds, the workers received the absorbed dose 0.03 - 14.78 μGy and effective dose 0.35 -7.59 μSv outside lead aprons and the highest absorbed dose 4.09 μGy and effective 0.22 μSv inside lead aprons, respectively, with more than 58.4% of rays shielded. For 2 cases of mediastinum cancers with implantation of 125Iseeds, the workers received the absorbed dose 0.06 - 74.91 μGy and effective dose 0.83-17.96 μSv outside lead aprons and the highest absorbed dose 10.29 μGy and effective 0.5 μSv inside lead aprons, respectively, with more than 85% of rays shielded. For one case of ovary cancer with implantation of 125I seeds

  6. Radiation exposure to anesthesiologist and nurse in the orthopedic room

    International Nuclear Information System (INIS)

    We report the radiation exposure dose received by the anesthesiologist and nurse in the orthopaedic operating room, when a fluoroscopic image intensifier is in use. This study was done in 12 femoral neck fracture operations performed from January to May 1995. Radiation was monitored with the MYDOSE MINIX PDM 107 made by Aloka Co. which were attached in front and behind the nurse's lead apron, in front of the lead apron of the anesthesiologist. The average imaging time was 9.78 min. The average radiation dose in front of the anesthesiologist is lead apron was 2.08μSV, and in front and behind the nurse's lead apron were 5.67μSV, 0.08μSV respectively. This study and review of the literature indicate that the operating room anesthesiologist and nurse receive a lower exposure than the orthopaedist. We can disregard the problem of radiation exposure to the anesthesiologist and nurse during an orthopaedic operation when they wear lead aprons and stand far from the patient. (author)

  7. Estimation of staff lens doses during interventional procedures. Comparing cardiology, neuroradiology and interventional radiology

    International Nuclear Information System (INIS)

    The purpose of this article is to estimate lens doses using over apron active personal dosemeters in interventional catheterisation laboratories (cardiology IC, neuroradiology IN and radiology IR) and to investigate correlations between occupational lens doses and patient doses. Active electronic personal dosemeters placed over the lead apron were used on a sample of 204 IC procedures, 274 IN and 220 IR (all performed at the same university hospital). Patient dose values (kerma area product) were also recorded to evaluate correlations with occupational doses. Operators used the ceiling-suspended screen in most cases. The median and third quartile values of equivalent dose Hp(10) per procedure measured over the apron for IC, IN and IR resulted, respectively, in 21/67, 19/44 and 24/54 μSv. Patient dose values (median/third quartile) were 75/128, 83/176 and 61/159 Gy cm2, respectively. The median ratios for dosemeters worn over the apron by operators ( protected by the ceiling-suspended screen) and patient doses were 0.36; 0.21 and 0.46 μSv Gy-1 cm-2, respectively. With the conservative approach used (lens doses estimated from the over apron chest dosemeter) we came to the conclusion that more than 800 procedures y-1 and per operator were necessary to reach the new lens dose limit for the three interventional specialties. (authors)

  8. Estimation of staff lens doses during interventional procedures. Comparing cardiology, neuroradiology and interventional radiology.

    Science.gov (United States)

    Vano, E; Sanchez, R M; Fernandez, J M

    2015-07-01

    The purpose of this article is to estimate lens doses using over apron active personal dosemeters in interventional catheterisation laboratories (cardiology IC, neuroradiology IN and radiology IR) and to investigate correlations between occupational lens doses and patient doses. Active electronic personal dosemeters placed over the lead apron were used on a sample of 204 IC procedures, 274 IN and 220 IR (all performed at the same university hospital). Patient dose values (kerma area product) were also recorded to evaluate correlations with occupational doses. Operators used the ceiling-suspended screen in most cases. The median and third quartile values of equivalent dose Hp(10) per procedure measured over the apron for IC, IN and IR resulted, respectively, in 21/67, 19/44 and 24/54 µSv. Patient dose values (median/third quartile) were 75/128, 83/176 and 61/159 Gy cm(2), respectively. The median ratios for dosemeters worn over the apron by operators (protected by the ceiling-suspended screen) and patient doses were 0.36; 0.21 and 0.46 µSv Gy(-1) cm(-2), respectively. With the conservative approach used (lens doses estimated from the over apron chest dosemeter) we came to the conclusion that more than 800 procedures y(-1) and per operator were necessary to reach the new lens dose limit for the three interventional specialties. PMID:25848117

  9. Dynamic Interaction Behavior between Jumbo Container Crane and Pile-Supported Wharf under NearField and Far-Field Ground Motions

    Directory of Open Access Journals (Sweden)

    J. R. LI

    2016-02-01

    Full Text Available Playing an important role in local and national seaport activities, container wharves are susceptible to structural failure and damage during earthquake events. Therefore, factors that affect the seismic response of crane–wharf structures under different types of earthquake ground motions should be elucidated. In this paper, 3D finite element models were established to investigate the differences of natural vibration characteristics between the wharf and crane–wharf structures. The dynamic response of a typical pile-supported wharf structure and the interaction behavior of a crane and wharf structural system under seismic actions of near-field and far-field ground motions were studied by performing numerical simulation and time-history response analysis. Axial force–moment relation curves were adopted to analyze the elastic–plastic limit state of the wharf structure under different ground motions. Results showed that the consideration of the container crane increased the natural vibration period of the pile-supported wharf structure and affected the dynamic characteristics of the structure. Compared with the far-field earthquake ground motion, the nearfield earthquake exerted a more significant impact on the structural dynamic response that controlled the elastic–plastic limit state. With the presence of a crane, the moment and shear force of the pile-top decreased and the location of the extreme value moved down obviously. The findings demonstrated that considering the crane changed the failure mechanism of the wharf structure, and the eccentric effect of the crane may amplify the dynamic response as the peak ground acceleration increases. The results provide reference for the seismic design and the evaluation of the seismic response of container wharves.

  10. Radiation dose in vertebroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Mehdizade, A.; Lovblad, K.O.; Wilhelm, K.E.; Somon, T.; Wetzel, S.G.; Kelekis, A.D.; Yilmaz, H.; Abdo, G.; Martin, J.B.; Viera, J.M.; Ruefenacht, D.A. [Neuroradiology DRRI, Geneva University Hospital, Rue Micheli-du-Crest 24, 1211, Geneva 14 (Switzerland)

    2004-03-01

    We wished to measure the absorbed radiation dose during fluoroscopically controlled vertebroplasty and to assess the possibility of deterministic radiation effects to the operator. The dose was measured in 11 consecutive procedures using thermoluminescent ring dosimeters on the hand of the operator and electronic dosimeters inside and outside of the operator's lead apron. We found doses of 0.022-3.256 mGy outside and 0.01-0.47 mGy inside the lead apron. Doses on the hand were higher, 0.5-8.5 mGy. This preliminary study indicates greater exposure to the operator's hands than expected from traditional apron measurements. (orig.)

  11. REVIEW ON LOCAL SCOUR DUE TO JETS

    Institute of Scientific and Technical Information of China (English)

    Arindam SARKAR; Subhasish DEY

    2004-01-01

    The safety of an apron of the energy dissipator is threatened by the large-scale scour in the downstream of the apron due to the erosive action of a horizontal jet issuing from a sluice opening. Also, large-scale deposition of the scoured sediments due to an impinging jet in a plunging pool type energy dissipator affects the passage of flow adversely in the downstream channels. Owing to the significant practical importance, the problem of local scour due to jets has been studied by many investigators. In this paper, a comprehensive review of the up-to-date investigations on local scour due to horizontal and impinging jets is presented including all possible aspects, such as scouring process, parameters affecting scour, time variation of scour,velocity distribution on the apron and within the scour hole, development of boundary layer thickness, bed shear stress, scour estimation formulas and protection works.

  12. Dosemeter readings and effective dose to the cardiologist with protective clothing in a simulated interventional procedure

    International Nuclear Information System (INIS)

    A personal dosemeter issued for individual monitoring is calibrated in terms of personal dose equivalent, usually HP(10). In general it yields a reasonable estimate of effective dose (E) when the exposed person does not wear protective clothing. In interventional cardiology, however, a lead equivalent apron is worn and often a thyroid collar. A correction factor will then be necessary to convert a dosemeter reading to E. To explore this factor an interventional cardiology procedure is simulated based on exposure conditions typical for a modern hospital in the BENELUX area. The dose to the cardiologist is investigated using Monte Carlo simulation of radiation transport. It is concluded that a personal dosemeter may best be worn outside the apron at a central position high on the chest for least dependence on the beam direction. It will overestimate E by roughly a factor of 20 (apron and thyroid collar of 0.25 mm Pb). (authors)

  13. The influence of a drop-hydraulic structure on the mountain stream channel regime - case study from the Polish Carpathians

    Directory of Open Access Journals (Sweden)

    Artur RADECKI-PAWLIK

    2013-06-01

    Full Text Available Basic hydraulic parameters such as shear stress, stream power, unit stream power and water velocities were calculated and measured within the region of a drop hydraulic structure erected on the Kasinczanka stream in the Polish Carpathians. Besides examining the hydrodynamics of the stream the study investigated also the distribution of grain size in the bed-load at the upstream and downstream aprons of the structure. It was revealed that grains deposited at the upstream apron were finer than those deposited at the downstream apron. At the same time, shear stresses and unit stream power values were found to be quite stable upstream of the drop structure, but to change significantly along the stream channel downstream of the structure’s energy dissipating pool

  14. Fuel element storage pond for nuclear installations

    International Nuclear Information System (INIS)

    In a fuel element storage pond for nuclear installations, with different water levels, radioactive particles are deposited at the points of contact of the water surface with the pond wall. So that this deposition will not occur, a metal apron is provided in the area of the points of contact of the water surface with the bond wall. The metal apron consists of individual sheets of metal which are suspended by claws in wall hooks. To clean the sheets, these are moved to a position below the water level. The sheets are suspended from the wall hooks during this process. (orig.)

  15. Utjecaj tretmana sjemena na sadržaj ulja u zrnu

    OpenAIRE

    ŠIMIĆ, BRANIMIR; Krizmanić, Miroslav; Liović, Ivica; Miljić, Anto; Bilandžić, Marijan; Popović, Ruža

    2006-01-01

    Zrno suncokreta specifičnih je svojstava s obzirom na genotip, proces dorade sjemena, tretman i skladištenje a uslijed toga često dolazi do promjene kemijskog sastava zrna. Ovim istraživanjem utvrđena je promjena kemijskog sastava zrna (sadžaj ulja, %/ST) opadanje energije klijanja i klijavosti sjemena suncokreta, a ispitivanje je obavljeno na netretiranom (kontrola) i tretiranom sjemenu (T1 : Apron 35 DS + Geocid ST-35 i T2 : Apron 35 DS + Chinok 600FS). Analizirano je sjeme dva hibrida sunc...

  16. Utjecaj uvjeta tretmana sjemena na kemijski sastav zrna suncokreta

    OpenAIRE

    ŠIMIĆ, BRANIMIR; Popović, Ruža; Andrić, Luka; Plavšić, Hrvoje; Ivanišić, Ilonka; Tihomir ČUPIĆ; Jurković, Zorica

    2005-01-01

    Istraživanjem je utvrđen utjecaj tretmana sjemena na kemijski sastav zrna suncokreta (Fakir i Apolon) tijekom skladištenja od 12 mjeseci. Naturalni i tretirani uzorci sjemena suncokreta s insekticidima Apron + Chinok, te Apron + Geocid, upakirani su u papirnatu dvoslojnu natron vreću i uskladišteni u betonsko-montažno skladište (vlaga zraka 60-75% i temperatura 20-25oC). Nakon 12 mjeseci sadržaj ulja u zrnu izmjeren je spektroskopskom metodom nuklearne magnetne rezonancije (NMR). Rezultati...

  17. Dose assessment of the patient and the helper in emergency head computed tomography

    International Nuclear Information System (INIS)

    Computed Tomography (CT) becomes more and more important and is frequently used in modern diagnostic techniques. CT offers an effective diagnosis on lesion and pathology; however, it also delivers a radiation dose to patients. Besides, in some special emergency cases, the patient may require someone to help him in the examination room to perform the head CT, due to the patient lost intellectual and operational capacity. This study evaluated the delivered radiation dose and the risk of radiation-induced cancer for the patient and for the helper after carrying out the emergent head CT examination. A Rando phantom with thermoluminescent dosimeter (TLD) chips inside relevant organs was used to simulate the patient during head CT examination. An effective dose of 2.06 ± 0.16 mSv and 1.46 ± 0.07 mSv without and with wearing the lead apron were found respectively, considering ICRP 60 recommendation. ICRP 103 recommendations the readings would have been 1.29 ± 0.15 mSv and 0.71 ± 0.04 mSv. The effective dose determined from the dose-length product (DLP) method (2.19 mSv) was similar to the value (2.06 ± 0.16 mSv) estimated by TLD method considering the ICRP 60 recommendation (without lead apron). Assuming a 5% total risk for fatal cancer per Sv in the general population, risk of radiation-induced cancer for patients were 1.03 × 10−2% (without lead apron) and 7.80 × 10−3% (with lead apron) for ICRP 60, and were 6.45 × 10−3% (without lead apron) and 3.55 × 10−3% (with lead apron) for ICRP 103. The dose received by the helper was assessed by wearing a personal badge. The helper during emergent head CT examination may receive a personal dose equivalent (Hp(10)) of 19.36 ± 5.89 μSv and 138.81 ± 101.28 μSv with and without lead apron, respectively, at distance of 0.3–1 m from the center of CT scanner. Based on the observed dose reduction of a factor of 7.17 we recommend that helpers wear lead apron in the CT examination room.

  18. Identification of irradiated crab using EPR

    Energy Technology Data Exchange (ETDEWEB)

    Maghraby, A. [Radiation Dosimetry Department, National Institute for Standards (NIS), Ministry of Scientific Research, Haram, 12211- Giza, P.O. Box: 136 (Egypt)]. E-mail: maghrabism@yahoo.com

    2007-02-15

    EPR spectroscopy is a fast and powerful technique for the identification of irradiated food. Crab exoskeleton was divided into six parts: dactyl, cheliped, carapace, apron, swimming legs, and walking legs. Samples of the exoskeleton were prepared and irradiated to Cs-137 gamma radiation in the range (1.156-5.365 kGy). EPR spectra of unirradiated as well as irradiated samples were recorded and analyzed. Response to gamma radiation was plotted for each part of the exoskeleton, dactyl was found to be the most sensitive part, followed by the apron (38%), cheliped (37%), walking legs (30%), swimming legs (24%), and carapace (21%) relative to the dactyl response.

  19. Identification of irradiated crab using EPR

    International Nuclear Information System (INIS)

    EPR spectroscopy is a fast and powerful technique for the identification of irradiated food. Crab exoskeleton was divided into six parts: dactyl, cheliped, carapace, apron, swimming legs, and walking legs. Samples of the exoskeleton were prepared and irradiated to Cs-137 gamma radiation in the range (1.156-5.365 kGy). EPR spectra of unirradiated as well as irradiated samples were recorded and analyzed. Response to gamma radiation was plotted for each part of the exoskeleton, dactyl was found to be the most sensitive part, followed by the apron (38%), cheliped (37%), walking legs (30%), swimming legs (24%), and carapace (21%) relative to the dactyl response

  20. Characterization of Textiles Used in Chefs' Uniforms for Protection Against Thermal Hazards Encountered in the Kitchen Environment.

    Science.gov (United States)

    Zhang, Han; McQueen, Rachel H; Batcheller, Jane C; Ehnes, Briana L; Paskaluk, Stephen A

    2015-10-01

    Within the kitchen the potential for burn injuries arising from contact with hot surfaces, flames, hot liquid, and steam hazards is high. The chef's uniform can potentially offer some protection against such burns by providing a protective barrier between the skin and the thermal hazard, although the extent to which can provide some protection is unknown. The purpose of this study was to examine whether fabrics used in chefs' uniforms were able to provide some protection against thermal hazards encountered in the kitchen. Fabrics from chefs' jackets and aprons were selected. Flammability of single- and multiple-layered fabrics was measured. Effect of jacket type, apron and number of layers on hot surface, hot water, and steam exposure was also measured. Findings showed that all of the jacket and apron fabrics rapidly ignited when exposed to a flame. Thermal protection against hot surfaces increased as layers increased due to more insulation. Protection against steam and hot water improved with an impermeable apron in the system. For wet thermal hazards increasing the number of permeable layers can decrease the level of protection due to stored thermal energy. As the hands and arms are most at risk of burn injury increased insulation and water-impermeable barrier in the sleeves would improve thermal protection with minimal compromise to overall thermal comfort. PMID:25925745

  1. Radiation dose measurement for patients and staff during cardiac catheterization

    International Nuclear Information System (INIS)

    The primary objective of this study was to determine the patient and staff dose during cardiac catheterization procedures in Ahmed Gasim Hospital, Khartoum Bahry. A survey of patient and staff exposure was performed covered 2 Cath Lab units from 2 manufacturers. The measurements involved 50 operations. The medical staff was monitored using TLD chips (LiF: Mg, Cu, P). The main operator who was closer to the patient and the x-ray tube, was monitored at six positions (forehead, neck chest - over the lead apron, waist - under the lead apron, leg, and hand), while the exposure to the assistant was measured at two positions (chest - over the lead apron, and hand), where the technologist and the circulator were monitored at one position (chest - over the lead apron). patient exposure was measured using the DAP meter. The main operator and the rest of the staff received 0.14, 0.01 mSv/y respectively. The estimated patient dose rate was found to be 125 mGy/min which considered higher than the recommended DRL for the continuous high mode fluoroscopy used in interventional radiology (100 mGy/min). The study concluded to the fact that the main operator received relatively high dose which is a direct result to the poor radiation protection in the department. (Author)

  2. 40 CFR 60.730 - Applicability and designation of affected facility.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Applicability and designation of affected facility. 60.730 Section 60.730 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... granules industry; and tunnel kilns, tunnel dryers, apron dryers, and grinding equipment that also...

  3. Nano particles as the primary cause for long-term sunlight suppression at high southern latitudes following the Chicxulub impact - evidence from ejecta deposits in Belize and Mexico

    DEFF Research Database (Denmark)

    Vajda, Vivi; Ocampo, Adriana; Ferrow, Embaie;

    2015-01-01

    Life on Earth was sharply disrupted 66 Ma ago as an asteroid hit the sea-floor in what is today Yucatan Peninsula, Mexico. Approximately 600 km3 of sedimentary rock were vapourized, ejected into the atmosphere and subsequently deposited globally as an ejecta apron and fallout layer. Proximal ejecta...

  4. Staff lens doses in interventional urology. A comparison with interventional radiology, cardiology and vascular surgery values.

    Science.gov (United States)

    Vano, E; Fernandez, J M; Resel, L E; Moreno, J; Sanchez, R M

    2016-03-01

    The purpose of this work is to evaluate radiation doses to the lens of urologists during interventional procedures and to compare them with values measured during interventional radiology, cardiology and vascular surgery. The measurements were carried out in a surgical theatre using a mobile C-arm system and electronic occupational dosimeters (worn over the lead apron). Patient and staff dose measurements were collected in a sample of 34 urology interventions (nephrolithotomies). The same dosimetry system was used in other medical specialties for comparison purposes. Median and 3rd quartile values for urology procedures were: patient doses 30 and 40 Gy cm(2); personal dose equivalent Hp(10) over the apron (μSv/procedure): 393 and 848 (for urologists); 21 and 39 (for nurses). Median values of over apron dose per procedure for urologists resulted 18.7 times higher than those measured for radiologists and cardiologists working with proper protection (using ceiling suspended screens) in catheterisation laboratories, and 4.2 times higher than the values measured for vascular surgeons at the same hospital. Comparison with passive dosimeters worn near the eyes suggests that dosimeters worn over the apron could be a reasonable conservative estimate for ocular doses for interventional urology. Authors recommend that at least the main surgeon uses protective eyewear during interventional urology procedures. PMID:26583458

  5. Dødsulykker ved bygningsbrande

    DEFF Research Database (Denmark)

    Leth, Peter Mygind; Gregersen, Markil Ebbe Gregers; Sabroe, Svend

    1998-01-01

    accidents with candles (9%). The largest risk groups were chronic alcoholics, handicapped and elderly people. In conclusion, warnings should be issued against smoking in bed and use of loose-fitting clothing while cooking on an open fire. Protective aprons and devices for use while smoking, self...

  6. Microbial lifestyles that enable survival in lithifying habitats

    DEFF Research Database (Denmark)

    Tamez-Hidalgo, Paulina

    2010-01-01

    The precipitation of carbonates in the travertine forming Narrow Gauge hot spring in Yellowstone National Park occurs at a rapid rate, whereby microorganisms that colonize the ponds and apron facies are required to overcome lithification. CO2-fixation by autotrophic microorganisms in this cation-...

  7. Mexican Folkart for Children.

    Science.gov (United States)

    Dominguez, Graciela; And Others

    Directions, suggested materials, and illustrations are given for making paper mache pinatas and masks, cascarones, Ojos de Dios, maracas, dresser scarf embroidery, burlap murals, yarn designs, paper plate trays, paper cut designs, the poppy, sarape aprons, and paper Mexican dolls. Filled with candy and broken, the pinata is used on most Mexican…

  8. 29 CFR 776.27 - Construction which is related to covered production.

    Science.gov (United States)

    2010-07-01

    ... construction of new appurtenances of a covered production establishment such as parking aprons, access roads..., within the State, of construction materials, such as sand, gravel, brick and other construction materials...) Construction of a new factory building, even though its use for interstate production upon completion may...

  9. Optimisation of staff protection

    International Nuclear Information System (INIS)

    It is important to minimize the radiation dose received by staff, but it is particularly important in interventional radiology. Staff doses may be reduced by minimizing the fluoroscopic screening time and number of images, compatible with the clinical objective of the procedure. Staff may also move to different positions in the room in an attempt to reduce doses. Finally, staff should wear appropriate protective clothing to reduce their occupational doses. This paper will concentrate on the optimization of personal shielding in interventional radiology. The effect of changing the lead equivalence of various protective devices on effective dose to staff has been studied by modeling the exposure of staff to realistic scattered radiation. Both overcouch x-ray tube/undercouch image intensified and overcouch image intensifier/undercouch x-ray tube geometries were simulated. It was deduced from this simulation that increasing the lead apron thickness from 0.35 mm lead to 0.5 mm lead had only a small reducing effect. By contrast, wearing a lead rubber thyroid shield or face mask is a superior means of reducing the effective dose to staff. Standing back from the couch when the x-ray tube is emitting radiation is another good method of reducing doses, being better than exchanging a 0.35 mm lead apron for a 0.5 mm apron. In summary, it is always preferable to shield more organs than to increase the thickness of the lead apron. (author)

  10. Patient and radiographer perspectives of two lead shielding devices for foetal dose reduction in CT scanning

    International Nuclear Information System (INIS)

    Aim: In many UK hospitals pregnant patients undergoing chest CT scans have lead shielding placed over their abdomen/pelvis in order to reduce foetal radiation dose. In the majority of cases conventional lead aprons are used even though these are not designed for the task. The purpose of the study was to compare these aprons with a new shielding device, from both patient and radiographer perspectives. Materials and methods: The study was performed using 35 volunteer radiographers who alternately acted as both radiographer and pregnant patient; pregnancy was simulated at the time of the study. In both roles the volunteers experienced the two products and then completed a questionnaire to determine the relative merits of the products in terms of weight, manoeuvrability and fit to patient shape. The study received local ethics committee approval (09/H1304/33). Results: Both patients and radiographers showed a strong preference for the new shielding device with average favourable ratings of 83% for radiographers and 72% for patients compared with 27% and 17% for the lead aprons. The new device was particularly favoured in terms of manoeuvrability (97% vs. 46%), fit to patient shape (91% vs. 17%) and the perceived weight reduction on the patient's abdomen. Conclusions: A new shielding device for foetal radiation protection in all stages of pregnancy has been evaluated and has been shown to be preferred by both patients and radiographers when compared to conventional lead aprons.

  11. Ranging Behaviour of Commercial Free-Range Laying Hens.

    Science.gov (United States)

    Chielo, Leonard Ikenna; Pike, Tom; Cooper, Jonathan

    2016-01-01

    In this study, the range use and behaviour of laying hens in commercial free-range flocks was explored. Six flocks were each visited on four separate days and data collected from their outdoor area (divided into zones based on distance from shed and available resources). These were: apron (0-10 m from shed normally without cover or other enrichments); enriched belt (10-50 m from shed where resources such as manmade cover, saplings and dust baths were provided); and outer range (beyond 50 m from shed with no cover and mainly grass pasture). Data collection consisted of counting the number of hens in each zone and recording behaviour, feather condition and nearest neighbour distance (NND) of 20 birds per zone on each visit day. In addition, we used techniques derived from ecological surveys to establish four transects perpendicular to the shed, running through the apron, enriched belt and outer range. Number of hens in each 10 m × 10 m quadrat was recorded four times per day as was the temperature and relative humidity of the outer range. On average, 12.5% of hens were found outside. Of these, 5.4% were found in the apron; 4.3% in the enriched zone; and 2.8% were in the outer range. This pattern was supported by data from quadrats, where the density of hens sharply dropped with increasing distance from shed. Consequently, NND was greatest in the outer range, least in the apron and intermediate in the enriched belt. Hens sampled in outer range and enriched belts had better feather condition than those from the apron. Standing, ground pecking, walking and foraging were the most commonly recorded activities with standing and pecking most likely to occur in the apron, and walking and foraging more common in the outer range. Use of the outer range declined with lower temperatures and increasing relative humidity, though use of apron and enriched belt was not affected by variation in these measures. These data support previous findings that outer range areas tend to be

  12. 赛络集聚纺专件器材的选择和管理%Selection and Management of the Accessories and the Parts for Siro-compact Spinning

    Institute of Scientific and Technical Information of China (English)

    魏俊虎

    2012-01-01

    In order to stablize the quality of siro-compact spinning,analysis is done to the imapct and the effect of the accessories and the parts on siro-compact spinning.Suggestion is given to selection and management of the accessories and the parts including the cot,the apron,the lattice apron,the ring,the traveller,the carbon fiber top apron cradle,the spacer with press bar,and the neumatic and the phneumatic and plate spring supported top arms.Comparative analysis of the production data of the two top arms and the impact of the conventional top apron cradle with the spacer and the carbon top apron cradle with the press bar on siro-compact spinning.Conclusion is made that selection and management of the accessories and the parts should be reinforced for better spinning quality of siro-compact spinning production.%为了稳定赛络集聚纺成纱质量,分析了专件器材对赛络集聚纺的影响和作用。分别对胶辊、胶圈、网格圈、钢领、钢丝圈、碳纤上销和压力棒隔距块及气动和板簧摇架等专件器材的选择和管理提出建议。通过对比,分析两种摇架的生产数据和普通上销及隔距块与碳纤上销及压力棒隔距块对赛络集聚纺的影响,最后强调加强赛络集聚纺专件器材的选用与管理,以进一步提高赛络集聚纺的成纱质量。

  13. Evaluation of radiation protection in interventional orthopedic procedures in Khartoum state

    International Nuclear Information System (INIS)

    In this study an evaluation of radiation safety and protection in interventional orthopedic procedures for the staff in three theatres in Khartoum state was conducted. To evaluate radiation protection program and staff knowledge with regard to radiation protection a questionnaire was designed and distributed among the staff there. Integrity check was conducted on the available radiation tools ( lead aprons) to ensure that they provide optimal protection when positioned appropriately. Also dose rate was measured around the theatre to evaluate the level of leakage radiation. Finally the absorbed dose to orthopedic specialists was measured during several procedures. The study showed the absence of most of the radiation protection and safety procedures that ensure the protection of of workers and lack of radiation protection program. The integrity check conducted on lead aprons showed uncapable crack in about 24% of the checked aprons. And in spite of this, there was no action taken to withdraw those faulty aprons or to replace them due to the acute shortage of the aprons available in the three centers and this will cause unjustified radiation exposure to the staff. The level of radiation around the theatres was found to fall within the acceptable limit according to the international commission of radiation protection (ICRP) recommendations that -if implemented -could improve the status of radiation protection in interventional orthopedic procedures. The improve. The important recommendations are to establish a single regulatory authority in Sudan independent from any user or promotion of radiation as well as to conduct periodically training courses for orthopedic staff on radiation protection in orthopedic interventional procedures.(Author)

  14. Acceso a los nuevos muelles en el puerto de Pasajes (España

    Directory of Open Access Journals (Sweden)

    Martínez Cebolla, Carlos

    1966-09-01

    Full Text Available This article describes the entry to the new wharves at Pasajes Harbour. This access route provides a means of entry of vehicles to the wharves, passing over the railway lines, and over the main N-1 national Madrid to Irun highway. The efficiency of this arrangement will be highly appreciated by the users of the harbour, and by foreign tourists, since Pasajes is close to the Irun-Behobia frontier. But the main purpose of this article is to describe the method of prestressing of one of the bridges involved in this project. It is one of the first applications of this system in Spain, though it is likely to become very widely used, due to its general efficiency. This project was inaugurated by the Minister of Public Works on March 28, 1966.En el presente artículo se describe la obra de los accesos a los Nuevos Muelles en Pasajes. Estos accesos tienen por objeto permitir la entrada y salida de vehículos a los muelles por encima de las vías de la Renfe y del Puerto y, además, sin producir ningún corte de circulación en la carretera nacional N-1 de Madrid a Irún. Su estética y funcionalidad será apreciada por los usuarios del Puerto y por los extranjeros, ya que se encuentra a pocos kilómetros de la frontera de Irún-Behobia. Pero el motivo principal del artículo ha sido la descripción de la solución de pretensado que se ha dado a uno de los puentes. Es una de las primeras obras ejecutadas en España de este tipo, aun cuando, lógicamente y dentro de unos años será un tipo de obra corriente, precisamente por la gran necesidad que hay de ellas. La obra fue inaugurada por el Excmo. Sr. Ministro de Obras Públicas el día 28 de marzo de 1966.

  15. Glass FRP reinforcement in rehabilitation of concrete marine infrastructure

    International Nuclear Information System (INIS)

    Fiber reinforced polymer (FRP) reinforcements for concrete structures are gaining wide acceptance as a suitable alternative to steel reinforcements. The primary advantage is that they do not suffer corrosion and hence they promise to be more durable in environments where steel reinforced concrete has a limited life span. Concrete wharves and jetties are examples of structures subjected to such harsh environments and represent the general class of marine infrastructure in which glass FRP (GFRP) reinforcement should be used for improved durability and service life. General design considerations which make glass FRP suitable for use in marine concrete rehabilitation projects are discussed. A case study of recent wharf rehabilitation project in Canada is used to reinforce these considerations. The structure consisted of a GFRP reinforced concrete deck panel and steel - GFRP hybrid reinforced concrete pile cap. A design methodology is developed for the hybrid reinforcement design and verified through testing. The results of a field monitoring program are used to establish the satisfactory field performance of the GFRP reinforcement. The design concepts presented in the paper are applicable to many concrete marine components and other structures where steel reinforcement corrosion is a problem. (author)

  16. Seismic Demands for Pile-Supported Wharf Structures with Batter Piles

    Directory of Open Access Journals (Sweden)

    Rouhollah Amirabadi

    2012-09-01

    Full Text Available This study develops an optimal Probabilistic Seismic Demand Model (PSDM for pile-supported wharves whit batter plies. Four bins with twenty non-near-field ground motions and three typical pile-supported wharf structures from western United States ports are used to determine an optimal PSDM by using Probabilistic Seismic Demand Analysis (PSDA. PSDA is used to compute the relationship between Engineering Demand Parameters (EDPs and earthquake Intensity Measures (IMs. An optimal PSDM should be practical, sufficient, effective and efficient-all tested through several IM-EDP pairs. It has been found that for these types of structures, the optimal model comprises a spectral IM, such as spectral acceleration and one of several EDPs. These EDPs are considered for local (moment curvature ductility factor, intermediate (displacement ductility factor and horizontal displacement of embankment and global (differential settlement between deck and behind land response quantities. The considered PSDMs are a critical component in performance-based seismic design and seismic risk assessment. Results can be used in probabilistic framework for performance-based design developed by Pacific Earthquake Engineering Research (PEER center.

  17. DISTRIBUTION OF BACTERIA IN SHELLFISH CULTURE AREA AROUND QINGDAO

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Bacteria numbers in water of coastal shellfish culture area around Qingdao were examined in April, August and October 1998 respectively. The results showed that the total numbers of heterotrophic and coliform bacteria in waters of the area and the specific geographical area varied with seasons. The highest populations were recorded during summer, I.e. 1.0×104~4.5×106cell/ml and 3.0×100~2.4×103cell/100ml, and with average values of 1.61×105cell/ml and 1.24×102cell/100ml respectively. The second highest populations occurred in autumn, and the lowest were in spring. The numbers of coliform bacteria were relatively low in waters near the mouths of bays and open part of the shellfish culture area, while those in waters near the estuaries of big rivers, wharves, navigation routes or the area in front of downtown areas were much higher than other areas. Single-index assessment of the environment quality of shellfish culture was made to indicate that the water sanitary quality in most of these areas are very good, however, some parts were serious polluted by the faeces of warm-blood animals. These results provided theoretical reference for the programming and organizing of shellfish culture.

  18. PRIVATE AND PUBLIC ENTERPRISE: FLETCHER CONSTRUCTION AND THE BUILDING OF NEW ZEALAND

    Directory of Open Access Journals (Sweden)

    Astrid Baker

    2002-01-01

    Full Text Available This paper shows how a New Zealand company, Fletcher Construction, created wealth in partnership with the state. The first Labour government was elected in 1935 with a firm commitment to full employment and a broad social security system. Because Labour’s determination to get things done through local industry coincided with James Fletcher’s, and then his son’s, drive for company expansion and profits. Fletchers’ design or construction of roads, wharves, saw-mills, flour mills, pulp mills, paper mills, factories, railway stations, university buildings, hospitals, department stores, office blocks, houses, and ownership and management of stone quarries, brickworks and forests, left a mark in almost every town and city in the country. Many projects required building methods and materials new to New Zealand, the innovative use of traditional materials, large-scale plant, specialist, skilled staff and technical know-how from United States and British construction and engineering firms. In this way Fletcher projects drew together many different suppliers, equipment makers, skilled tradesmen and financiers. As a provider of employment in construction and manufacturing, with easy access to established business and political leaders and a powerful influence on policy making, the company became a potent force in New Zealand’s full employment welfare state.

  19. Seismic Risk Assessment of Italian Seaports Using GIS

    International Nuclear Information System (INIS)

    Seaports are crucial elements in the export and import of goods and/or on the flow of travellers in the tourism industry of many industrialised nations included Italy. Experience gained from recent earthquakes (e.g. 1989 Loma Prieta in USA, 1995 Hyogoken-Nanbu and 2003 Tokachi-Oki in Japan) have dramatically demonstrated the seismic vulnerability of seaport structures and the severe damage that can be caused by ground shaking. In Italy, the Department of Civil Protection has funded a research project to develop a methodology for the seismic design of new marginal wharves and assessment of existing structures at seaports located in areas of medium or high seismicity. This paper shows part of the results of this research project, currently underway, with particular reference to the seismic risk assessment through an interactive, geographically referenced database (GIS). Standard risk assessment have been carried out for the Gioia Tauro port in Calabria (Italy) using the empirical curves implemented by the National Institute of Building Sciences (NIBS, 2004)

  20. Aircraft Detection in High-Resolution SAR Images Based on a Gradient Textural Saliency Map

    Directory of Open Access Journals (Sweden)

    Yihua Tan

    2015-09-01

    Full Text Available This paper proposes a new automatic and adaptive aircraft target detection algorithm in high-resolution synthetic aperture radar (SAR images of airport. The proposed method is based on gradient textural saliency map under the contextual cues of apron area. Firstly, the candidate regions with the possible existence of airport are detected from the apron area. Secondly, directional local gradient distribution detector is used to obtain a gradient textural saliency map in the favor of the candidate regions. In addition, the final targets will be detected by segmenting the saliency map using CFAR-type algorithm. The real high-resolution airborne SAR image data is used to verify the proposed algorithm. The results demonstrate that this algorithm can detect aircraft targets quickly and accurately, and decrease the false alarm rate.

  1. Evaluation of radiation exposure of workers caring for the patient after administration of radionuclide I-131 based on the Monte Carlo

    International Nuclear Information System (INIS)

    In the paper using the Monte Carlo method ( code MCNPX) were calculated absorbed doses in organs caregivers, from which thereafter was set the value of the equivalent dose in these organs by appropriate formulas and then effective doses in selected geometries using protective shielding devices. The results show that using of shielding aprons equivalent of 1 mm of lead will reduce the exposure of workers caring for patients after administration of the radionuclide I-131 by about 30%. If the caregiver without protective shielding aprons is located between two patients, the gamma rays will be reduced by about 18% due to averted body of caregiver, while the worker's personal dosimeter located at the chest will register approximately 40% lower value of personal dose equivalent. (authors)

  2. X-ray face mask and bib device

    International Nuclear Information System (INIS)

    An x-ray protective face mask is made of a relatively transparent lead containing radiation shielding plastics material, and is removably attachable to a chest or bib shield for application of the device to and support upon the shoulders of a technician or a patient. Alternatively, the face mask is formed of a lens portion supported in a plastics frame, upon the lower portion of which is removably attached a bib shield that in turn is removably attachable to an apron. The frame of the face mask, bib shield and apron are preferably lined with lead sheets to protect the neck, face, chest and body of the technician from the random secondary or scatter x-ray beams. The face mask and bib shield can be formed of a moulded plastics material as a unitary device, the lens portion being attached to the frame therefor. (author)

  3. Effects of hygiene-sanitary measures on microbiological safety of finished product in butter production plant

    OpenAIRE

    Memiši Nurgin; Škrinjar Marija; Vesković-Moračanin Slavica

    2012-01-01

    This work presents the results of investigations of the effects of hygienesanitary measures at critical points in the technological process of butter production on its quality and microbiological safety. With this object in mind, hygiene safety was checked using the swab method at the machine for churning and packing butter (125 g packages and bulk butter), the equipment, hands and clothing (work aprons) of employees directly engaged on the machines. The ev...

  4. Finite Element Analysis on the Pre-load Structures of the Central Solenoid for the HT-7U Device

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The central solenoid is an important part of the HT-7U device. In this paper, the computational analysis of the stress and the displacement on the pre-load structures of the central solenoid have been made by the finite element analysis system COSMOS/M2.0 under room and/or operating temperature. According to the analytical results, the clip aprons and compression plates are all satisfied with safety design criteria.

  5. Potential hydroelectric power. Vertical turbine: spillway combine Broadwater Dam. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Willer, D.C.

    1979-04-23

    A feasibility study was made of the hydroelectric power potential at Broadwater Dam in western Montana. Two alternative configurations for the potential project were evaluated and the economics of four possible sources of project funding were assessed. The configurations analyzed were an apron-mounted configuration, in which the turbine-generator units are located on the downstream apron of the existing dam, and a conventional configuration, in which the units are located in a new powerhouse adjacent to the existing dam. The funding sources considered were the Department of Energy loan program, the United States Bureau of Reclamation PL-984 loan program and conventional revenue bonds, both taxable and tax-exempt. The optimal project alternative was determined to be the apron-mounted configuration. The final choice of funding would be dependent on the power purchaser. It was shown that, regardless of the configuraton or funding source selected, the project would be feasible. The cost of the apron-mounted configuration, which would consist of four turbine-generator units for a total installed capacity of 9.76 MW, was estimated as $13,250,000 with financing provided by either a PL-984 loan or tax-exempt bonds. The cost per installed kilowatt was therefore $1,350, and the cost per kilowatt-hour was 19.6 mills. The average annual energy was estimated to be 56.44 million kWh, the equivalent of approximately 87,000 barrels of oil per y. It is therefore recommended that the Montana Department of Natural Resources and Conservation proceed with the project and that discussions be initiated with potential power purchasers as soon as possible.

  6. Installation of dental x-ray units

    International Nuclear Information System (INIS)

    The purpose of the x-ray units is to perform intra oral perapical and occlusal examinations. Radiation requirements include, 1.5mm A1 filtration tube (upto 70kv), focus film distance between 10cm and 20cm for 60kv or less, a field defining spacer cone with a diameter of 6cm beam on the film must be used, an apron (lead) to protect the patient, a long cable 1 metre long for operator

  7. Estimation of staff doses in complex radiological examinations using a Monte Carlo computer code

    International Nuclear Information System (INIS)

    The protection of medical personnel in interventional radiology is an important issue of radiological protection. The irradiation of the worker is largely non-uniform, and a large part of his body is shielded by a lead apron. The estimation of effective dose (E) under these conditions is difficult and several approaches are used to estimate effective dose involving such a protective apron. This study presents a summary from an extensive series of simulations to determine scatter-dose distribution around the patient and staff effective dose from personal dosimeter readings. The influence of different parameters (like beam energy and size, patient size, irradiated region, worker position and orientation) on the staff doses has been determined. Published algorithms that combine readings of an unshielded and a shielded dosimeter to estimate effective dose have been applied and a new algorithm, that gives more accurate dose estimates for a wide range of situations was proposed. A computational approach was used to determine the dose distribution in the worker's body. The radiation transport and energy deposition was simulated using the MCNP4B code. The human bodies of the patient and radiologist were generated with the Body Builder anthropomorphic model-generating tool. The radiologist is protected with a lead apron (0.5 mm lead equivalent in the front and 0.25 mm lead equivalent in the back and sides) and a thyroid collar (0.35 mm lead equivalent). The lower-arms of the worker were folded to simulate the arms position during clinical examinations. This realistic situation of the folded arms affects the effective dose to the worker. Depending on the worker position and orientation (and of course the beam energy), the difference can go up to 25 percent. A total of 12 Hp(10) dosimeters were positioned above and under the lead apron at the neck, chest and waist levels. Extra dosimeters for the skin dose were positioned at the forehead, the forearms and the front surface of

  8. Literature Review on Possible Alternatives to Tar for Antiskid Layers

    OpenAIRE

    Xiao, Y

    2010-01-01

    In airports, there are different areas such as runways, taxiways, aprons and parking areas. For runways, good skid resistance and water drainage of the surface layer is necessary. Tar, because of its good adhesion properties and other advantages as mentioned above, is widely used in thin, high skid resistance surfaces. Tar however is toxic and carcinogenic because of its high benzene content. This material did not meet the Dutch environmental standards. In the Netherlands and many other count...

  9. Is extremity monitoring recommended for interventional cardiologists?

    International Nuclear Information System (INIS)

    Interventional Cardiology procedures are normally associated with long exposure times and high doses in patients and cardiologists. The aim of this study is to estimate the personal dose equivalent at several points on the staff's body to verify the places on the body that receive the highest doses and to evaluate the necessity of extremity additional monitoring. The dosimetric measurements have been carried out in a hemodynamic room during procedures of Coronary Angiography (CA) and Percutaneous Transluminal Coronary Angioplasty (PTCA). The dosimetry was done using LiF:Mg,Ti thermoluminescent dosimeters at different points on the medical staff's body (left and right wrists and above and under the lead apron). To CA procedures, the highest doses measured were 0.52 mSv for the left wrist of main doctors and 0.38 mSv above the lead apron of assistant cardiologist. To PTCA procedures, the highest doses obtained were 1.19 mSv above the lead apron of main doctors and 2.81 mSv for the left wrist of assistant doctor. Doses at PTCA procedures were higher than CA procedures. For main cardiologists, the dose in the left wrist was higher than in the right one, which are sometimes higher than the dose on the chest above the lead apron. This indicates the recommendation of additional extremity monitoring of hemodynamic main doctor. To assistant cardiologists the use of only one individual monitor at this position is enough. Besides the measurement of doses, to apply the concepts of radiation protection is important to reduce the doses received by staff and patients. (author)

  10. Accuracy of effective dose estimation in personal dosimetry: a comparison between single-badge and double-badge methods and the MOSFET method.

    Science.gov (United States)

    Januzis, Natalie; Belley, Matthew D; Nguyen, Giao; Toncheva, Greta; Lowry, Carolyn; Miller, Michael J; Smith, Tony P; Yoshizumi, Terry T

    2014-05-01

    The purpose of this study was three-fold: (1) to measure the transmission properties of various lead shielding materials, (2) to benchmark the accuracy of commercial film badge readings, and (3) to compare the accuracy of effective dose (ED) conversion factors (CF) of the U.S. Nuclear Regulatory Commission methods to the MOSFET method. The transmission properties of lead aprons and the accuracy of film badges were studied using an ion chamber and monitor. ED was determined using an adult male anthropomorphic phantom that was loaded with 20 diagnostic MOSFET detectors and scanned with a whole body CT protocol at 80, 100, and 120 kVp. One commercial film badge was placed at the collar and one at the waist. Individual organ doses and waist badge readings were corrected for lead apron attenuation. ED was computed using ICRP 103 tissue weighting factors, and ED CFs were calculated by taking the ratio of ED and badge reading. The measured single badge CFs were 0.01 (±14.9%), 0.02 (±9.49%), and 0.04 (±15.7%) for 80, 100, and 120 kVp, respectively. Current regulatory ED CF for the single badge method is 0.3; for the double-badge system, they are 0.04 (collar) and 1.5 (under lead apron at the waist). The double-badge system provides a better coefficient for the collar at 0.04; however, exposure readings under the apron are usually negligible to zero. Based on these findings, the authors recommend the use of ED CF of 0.01 for the single badge system from 80 kVp (effective energy 50.4 keV) data. PMID:24670903

  11. Depositional Patterns and Oil/Gas Accumulation Features of Sha-3 Member Turbidites in Dongying Depression, Bohai Bay Basin

    Institute of Scientific and Technical Information of China (English)

    BaiGuoping; ZhangShanwen

    2004-01-01

    Recent exploration results indicate that a significant exploration potential remains in the Dongying Depression of the Bohai Bay Basin and the undiscovered oil and gas are largely reservoired in subtle traps including turbidite litholigeal traps of the Sha-3 Member. In order to effectively guide the exploration program targeting turbidites, this study will focus on the depositional models of the Sha-3 Member turbidites and oil/gas accumulation characteristics in these turbidites. Two corresponding relationships were found. One is that the East African Rift Valley provides a modem analog for the depositionai systems in the Dongying Depression. The other is that the depositional models of line-sourced slope aprons, single point-source submarine fan and multiple source romp turbidite, established for deep.sea turbidites, can be applied to interpret the depositional features of the turbidite fans of three differant origins: slope turbidite aprons, lake floor turbidite fans and delia-fed turbidite fans in the Sha-3 Member. Updip sealing integrity is the key factor determining whether oil/gas accumulates or not in the slope aprons and lake floor fans. The factors controlling oil/gas migration and accumulation in the delta-ted turbidite fans are not very clear. Multiple factors rather than a single factor probably played significant roles in these processes.

  12. Dosimetry in Interventional Radiology - Effective Dose Estimation

    International Nuclear Information System (INIS)

    Interventional radiological procedures can lead to significant radiation doses to patients and to staff members. In order to evaluate the personal doses with respect to the regulatory dose limits, doses measured by dosimeters have to be converted to effective doses (E). Measurement of personal dose equivalent Hp(10) using a single unshielded dosimeter above the lead apron can lead to significant overestimation of the effective dose, while the measurement with dosimeter under the apron can lead to underestimation. To improve the accuracy, measurements with two dosimeters, one above and the other under the apron have been suggested (double dosimetry). The ICRP has recommended that interventional radiology departments develop a policy that staff should wear two dosimeters. The aim of this study was to review the double dosimetry algorithms for the calculation of effective dose in high dose interventional radiology procedures. The results will be used to develop general guidelines for personal dosimetry in interventional radiology procedures. This work has been carried out by Working Group 9 (Radiation protection dosimetry of medical staff) of the CONRAD project, which is a Coordination Action supported by the European Commission within its 6th Framework Program.(author)

  13. Interim report of the JHPS expert committee on radiation protection of the lens of the eye (2). The dosimetry method for the lens of the eye of workers in Japan

    International Nuclear Information System (INIS)

    A brief review is given of the history and methodology of external dosimetry for the lens of the eye. Under the 1989 revision to domestic radiological protection regulations, the concept on the effective dose equivalent and the dose limit to the lens of the eye (150 mSv/y) both introduced in the ICRP 1977 recommendations has changed nationwide the external monitoring methodology in non-uniform exposure situations to the trunk of a radiological worker. In such situations, which are often created by the presence of a protective apron, the worker is required to use at least two personal dosemeters, one worn on the trunk under the apron and the other, typically, at the collar over the apron. The latter dosemeter serves the dual purpose of providing the dose profile across the trunk for improved effective dose equivalent assessment and of estimating the dose to lens of the eye. The greater or appropriate value between Hp(10) and Hp(0.07), given by the dosemeter, is generally used as a surrogate of Hp(3) for recording the dose to the lens of the eye. The above-mentioned methodology was continued in the latest 2001 revision to the relevant regulations. (author)

  14. Management of diagnostic x-ray radiation in developing countries

    International Nuclear Information System (INIS)

    The purpose of this study is to provide a simple, inexpensive, and effective method to prevent the scattering of x-ray radiation by using a lead apron in the x-ray rooms of developing countries. In developed countries, the scattering of x-ray radiation among patients and radiographers in diagnostic x-ray rooms has been minimized by various methods. However, in some developing countries, scattered x-ray radiation has not yet been adequately contained. The policy of As Law As Reasonably Achievable (ALARA) requires that patients who are waiting for their examinations must be protected from scattered x-ray radiation. However, from the author's experience, protection from scattered x-ray radiation in x-ray rooms is often insufficient in developing countries. In addition, major public hospitals in big cities are overwhelmed with patients because radiology resources in developing countries are concentrated in the big cities. Moreover, the situation is made worse by short working hours in public hospitals. Hours from 10 a.m. to 3 p.m. are typical. Because of the circumstances, radiographers, who are in a rush to finish all of the examinations within their normal working hours, sometimes allow patients to enter the x-ray rooms while they are waiting for their examinations. Chest and abdominal x-rays are the most common kinds of diagnostic x-ray examination in developing countries. Thus, in this study, anthropomorphic chest and abdominal phantoms were x-rayed for measuring the scattered x-ray radiation with and without protection using a 0.25mmPb lead apron at specific points from the anthropomorphic phantoms in the x-ray room. The lead apron was hung on a mobile apron-hanger and placed next to the anthropomorphic phantom. The scattered radiation dosimetry for chest x-rays proves that this simple method reduces scattered x-ray radiation to 15% at one-meter point and to almost 0% at the two-meter point from the anthropomorphic phantom in the x-ray room. Lead aprons are

  15. The colossal task of Ouranos

    International Nuclear Information System (INIS)

    Ouranos is a new consortium on climatology and adaptation to climate change consisting of researchers from Hydro-Quebec, the Quebec government and the Meteorological Service of Canada who are analyzing the long-range trends and regional impacts of climate change. One general trend that has been pointed out by the Intergovernmental Panel on Climate Change (IPCC) is that the average global temperature rose faster in the past century (+0.6 degrees C) than in the preceding thousand years. It is expected to rise 1.6 to 6 degrees C by the end of the twenty-first century. The rise in temperature has already resulted in a global loss of snow cover, glacial melt at the North Pole, increased precipitation worldwide, and rising sea levels. The IPCC cautions that the world's climate system could break down within a few decades if emissions of carbon dioxide and other greenhouse gases continue at the current rate. The signs of climate change that have already been observed in Quebec include a high number of stationary weather patterns that are expressed in long cold snaps in winter and severe summer droughts. Decision makers are faced with the challenge of how to manage water resources and predict the impact of changes in precipitation on forest fire frequency and insect infestation. In addition, they must determine if adjustments should be made to the design of treatment plant intakes, the height of harbour wharves, and dike dimensions. In order to help plan the future, Ouranos has invested $2.5 million into a supercomputer that will be drawing the North American weather map for the period 2040-2065 to evaluate various scenarios through a reliable meteorological model. 4 figs

  16. Development of double dosimetry algorithm for assessment of effective dose to staff in interventional radiology

    International Nuclear Information System (INIS)

    Medical staff involving interventional radiology(IR) procedures are significantly exposed to the scatter radiation because they stand in close proximity to the patient. Since modern IR techniques are often very complicated and require extended operation time, doses to IR workers tend to increase considerably. In general, the personal dose equivalent at 10 mm depth, Hp(10), read from one dosimeter worn on the trunk of a radiation worker is assumed to be a good estimate of the effective dose and compared to the dose limits for regulatory compliance. This assumption is based on the exposure conditions that the radiation field is broad and rather homogeneous. However, IR workers usually wear protective clothing like lead aprons and thyroid shield which allow part of the body being exposed to much higher doses. To solve this problem, i.e. to adequately estimate the effective doses of IR workers, use of double dosimeters, one under the apron and one over the apron where unshielded part of the body exposed, was recommended. Several algorithms on the interpretation of the two dosimeter readings have been proposed. However, the dosimeter weighting factors applied to the algorithm differ significantly, which quests a question on the reliability of the algorithm. Moreover, there are some changes in the process of calculating the effective dose in the 2007 recommendations of the International Commission on Radiological Protection(ICRP): changes in the radiation weighting factors, tissue weighting factors and the computational reference phantoms. Therefore, this study attempts to set a new algorithm for interpreting two dosimeter readings to provide a proper estimate of the effective dose for IR workers, incorporating those changes in definition of effective dose. The effective doses were estimated using Monte Carlo simulations for various practical conditions based on the vogel reference phantom and the new tissue weighting factors. A quasi-effective dose, which is determined

  17. Estimation of the Dose of Radiation Received by Patient and Physician During a Videofluoroscopic Swallowing Study.

    Science.gov (United States)

    Morishima, Yoshiaki; Chida, Koichi; Watanabe, Hiroshi

    2016-08-01

    Videofluoroscopic swallowing study (VFSS) is considered the standard diagnostic imaging technique to investigate swallowing disorders and dysphagia. Few studies have been reported concerning the dose of radiation a patient receives and the scattering radiation dose received by a physician during VFSS. In this study, we investigated the dose of radiation (entrance skin dose, ESD) estimated to be received by a patient during VFSS using a human phantom (via a skin-dose monitor sensor placed on the neck of the human phantom). We also investigated the effective dose (ED) and dose equivalent (DE) received by a physician (wearing two personal dosimeters) during an actual patient procedure. One dosimeter (whole body) was worn under a lead apron at the chest, and the other (specially placed to measure doses received by the lens of the eye) outside the lead apron on the neck collar to monitor radiation doses in parts of the body not protected by the lead apron. The ESD for the patient was 7.8 mGy in 5 min. We estimated the average patient dose at 12.79 mGy per VFSS procedure. The physician ED and DE during VFSS were 0.9 mSv/year and 2.3 mSv/year, respectively. The dose of radiation received by the physician in this study was lower than regulatory dose limits. However, in accordance with the principle that radiation exposure should be as low as reasonably achievable, every effort should be made (e.g., wearing lead glasses) to reduce exposure doses. PMID:27318941

  18. Measuring the Weathertight Performance of Flashings

    Directory of Open Access Journals (Sweden)

    Mark Bassett

    2015-01-01

    Full Text Available Residential buildings are now better engineered to manage rainwater following the leaking building problem in New Zealand. The next challenge is to improve the weathertightness of medium-rise buildings which often use joint details widely applied on low-rise buildings but are subject to higher wind pressures and surface runoff rates. This study begins to address this challenge by measuring the water leakage performance limits of the following common flashings with static and dynamic rain and wind loads to see how their performance might be improved: (a Horizontal H and Z jointers between direct fixed sheet claddings; (b The window head flashing in a cavity wall; (c A horizontal apron flashing at the junction between a roof and wall. At this stage, water penetration resistances have been measured but the data has not yet been discussed in the context of wind pressures and rain loads on mid-rise buildings. All of the joints were found to resist water leakage to pressures equivalent to the hydrostatic head of the upstand, so long as there were no air leakage paths through the joint. When vents were added, or openings were present that might arise due to construction tolerances, then the onset pressure for leakage was found to fall by as much as 50%. Vents, of course, are essential for ventilation drying in rainscreen walls and even with vents present, the onset of leakage was at generally at least twice the 50 Pa wet wall test pressure applied in New Zealand. Opportunities were found to improve the way vented joints deal with runoff by enlarging the gap between the cladding and flashing. This prevented the outer joint volume from filling with water and occluding the vents. The apron flashing was found to cope better than a window head joint with runoff, because of the larger 35 mm vertical gap between the cladding and apron.

  19. Laminae development in opal-A precipitates associated with seasonal growth of the form-genus Calothrix (Cyanobacteria), Rehai geothermal area, Tengchong, Yunnan Province, China

    Science.gov (United States)

    Jones, Brian; Peng, Xiaotong

    2015-04-01

    The western discharge apron at Meinuquan (Rehai geothermal area, Yunnan Province, China), which incorporates the upper terrace, terrace front, and lower terrace, is covered with laminated opal-A precipitates that have formed from the spring waters that flow across its surface. Laminae are formed of silicified Calothrix mats or featureless opal-A that contains no microbes, scattered spherical and rod-shaped microbes, and/or rare Calothrix. Rapid silicification of the Calothrix led to preservation of their basal heterocysts, vegetative cells, trichomes, tapering filaments, and laminated and splayed sheaths. The Calothrix mats grew during the dry season when there was maximum sunlight because of low cloud cover. During this time, the mats grew under stable conditions because the water that flowed across the discharge apron was sourced from the springs, and temperature and water geochemistry was more or less constant. Growth of the Calothrix mats decreased during the wet season (April to late September) when sunlight is reduced due to the extensive cloud cover associated with the monsoonal rains. During the wet season, water flowing over the discharge apron is a mixture of rainwater, runoff from the surrounding hillsides, and spring water. Such variable flow conditions, water temperatures, and water geochemistry curtailed microbe growth and impacted silica precipitation. The precipitates at Meinuquan are like those associated with some Icelandic hot springs. Although growth of Calothrix is controlled by sunlight in both settings, the periods of maximum sunlight in China (October-March) and Iceland (June-August) are at different times of the year because of their geographic locations.

  20. Laboratory reconstruction of personal doses in interventional radiology and cardiology

    International Nuclear Information System (INIS)

    People working in interventional cardiology represent one of the most occupationally exposed groups. As recommended by the ICRP, these workers should be equipped with two personal dosemeters, one of them worn on the neck outside the protective collar and the second one on the trunk under the protective apron. It is proved that this double dosimetry method provides more precise estimate of effective dose. In connection with the new lower limit of the eye lens dose, the demands on the eye lens dose estimate increase. The aim of our experiment was to examine the relation between eye lens dose and the quantities Hp(10),Hp(3) or Hp(0.07) measured with conventional personal dosemeters worn on neck and chest. Irradiation conditions imitating the common operation of interventional radiology were created in the laboratory. The patient's body was substituted for a slab PMMA phantom (30 cm x 30 cm x 15 cm). An anthropomorphic Random phantom representing a physician was clothed in a protective apron and a collar, with equivalent of 0.5 mm Pb for both. Three personal multicomponent whole-body thermoluminescent dosemeters (TLD), which allow to measure personal dose equivalents Hp(10),Hp(3) and Hp(0.07), were fixed the Random phantom, one on the collar on the neck and two on the chest over and under the apron. The use of the third dosemeter outside the apron, beyond the recommended double dosimetry, was motivated by the fact that the double dosimetry is not preferred in the Czech Republic yet. Moreover, a special TLD called EYE-D, measuring Hp(3), was employed to determine eye lens dose. It was placed on the Random phantom's temple in the proximity of the eye closer to the radiation source. The utilized PMMA slab phantom was irradiated with X-ray source with the quality RQR5 in four typical irradiation geometries, i.e. radiation beam entered the patient from the front, back, left and right side, which was simulated by the respective arrangement of both the phantoms

  1. Child's organism's burden in radiological examinations in stomatology

    International Nuclear Information System (INIS)

    Plastic holders were developed for fixing a photographic film in the patient's mouth in stomatological radiodiagnostic examinations of children. The holder serves to reduce the radiation burden of children. In addition, patient's gonads are protected with a shield, a lead apron or a cloth with a lead lining at least 1.5 mm thick. Also developed was a protective shield from a 2.0 mm lead sheet for intraoral examinations. The shield is to be installed in children stomatology offices. (H.S.)

  2. Dental radiology in preventive dentistry

    International Nuclear Information System (INIS)

    Preventive measures in dental radiography for radiation protection of both the patients and occupational personnel (and at the same time giving maximum diagnostic yield) are described. The amount of X-radiation to the patients can be reduced by filtration and collimation of X-ray beam, eliminating tube-head leakage and using lead impregnated aprons while radiographing children and female patients in their reproductive age. Exposure of the operator can be minimized by the proper choice of his position and distance from the radiation source and placing a barrier between him and the source. (M.G.B.)

  3. Occupational radiation doses in interventional radiology: Simulations

    International Nuclear Information System (INIS)

    In interventional radiology, occupational radiation doses can be high. Therefore, many authors have established conversion coefficients from the dose-area product data or from the personal dosemeter reading to the effective dose of the radiologist. These conversion coefficients are studied also in this work, with an emphasis on sensitivity of the results to changes in exposure conditions. Comparison to earlier works indicates that, for the exposure conditions examined in this work, all previous models discussed in this work overestimate the effective dose of the radiologist when a lead apron and a thyroid shield are used. Without the thyroid shield, underestimation may occur with some models. (authors)

  4. Development of gonad protectors to be used in children radiology from recycled materials

    International Nuclear Information System (INIS)

    The use of medical radiology as a diagnostic tool has become a common practice and its benefits are undeniable, however, the radiological protection of patients has become a constant concern of the international community. Since children have a longer life expectancy, the risks of stochastic effects increase significantly. Thus, this study developed and designed gonads protectors, taking into account the anatomy, dimensions and ages of pediatric patients, reducing exposure to the primary beam by 94%. Furthermore, as a result of a secondary objective,success was obtained in reusing discarded as defective aprons. (author)

  5. Uranium Mill Tailings Remedial Action Project (UMTRAP), Slick Rock, Colorado, Revision 1, Volume 3. Calculations, Final design for construction

    International Nuclear Information System (INIS)

    Volume three contains calculations for: site hydrology--rainfall intensity, duration, and frequency relations; site hydrology-- probable maximum precipitation; erosion protection--rock quality evaluation; erosion protection--embankment top and side slope; erosion protection--embankment toe apron; erosion protection-- gradations and layer thicknesses; Union Carbide site--temporary drainage ditch design; Union Carbide site--retention basin sediment volume; Union Carbide site--retention basin sizing; Burro Canyon site temporary drainage--temporary drainage facilities; and Union Carbide site temporary drainage--water balance

  6. Cerebral angiography: a device to reduce exposure to the eye lens

    International Nuclear Information System (INIS)

    A simple inexpensive eyeshield, made of thin sheets of lead apron material laminated to a 5- x 15-cm sheet of x-ray film base, which is taped to the temple nearest the lateral x-ray tube prior to the completion of standard simultaneous biplane posteroanterior (PA) and lateral angiograms, results in a significant reduction in radiation exposure to the lens of the eye. The shield protects the eye lens without significantly impairing the quality of the radiographs. Compared with reported radiation exposure for standard cerebral vascular angiography, use of this device can produce a 20-fold drop in radiation exposure to the lens

  7. Emissions of NOx, particle mass and particle numbers from aircraft main engines, APU's and handling equipment at Copenhagen Airport

    Science.gov (United States)

    Winther, Morten; Kousgaard, Uffe; Ellermann, Thomas; Massling, Andreas; Nøjgaard, Jacob Klenø; Ketzel, Matthias

    2015-01-01

    This paper presents a detailed emission inventory for NOx, particle mass (PM) and particle numbers (PN) for aircraft main engines, APU's and handling equipment at Copenhagen Airport (CPH) based on time specific activity data and representative emission factors for the airport. The inventory has a high spatial resolution of 5 m × 5 m in order to be suited for further air quality dispersion calculations. Results are shown for the entire airport and for a section of the airport apron area ("inner apron") in focus. The methodology presented in this paper can be used to quantify the emissions from aircraft main engines, APU and handling equipment in other airports. For the entire airport, aircraft main engines is the largest source of fuel consumption (93%), NOx, (87%), PM (61%) and PN (95%). The calculated fuel consumption [NOx, PM, PN] shares for APU's and handling equipment are 5% [4%, 8%, 5%] and 2% [9%, 31%, 0%], respectively. At the inner apron area for handling equipment the share of fuel consumption [NOx, PM, PN] are 24% [63%, 75%, 2%], whereas APU and main engines shares are 43% [25%, 19%, 54%], and 33% [11%, 6%, 43%], respectively. The inner apron NOx and PM emission levels are high for handling equipment due to high emission factors for the diesel fuelled handling equipment and small for aircraft main engines due to small idle-power emission factors. Handling equipment is however a small PN source due to the low number based emission factors. Jet fuel sulphur-PM sensitivity calculations made in this study with the ICAO FOA3.0 method suggest that more than half of the PM emissions from aircraft main engines at CPH originate from the sulphur content of the fuel used at the airport. Aircraft main engine PN emissions are very sensitive to the underlying assumptions. Replacing this study's literature based average emission factors with "high" and "low" emission factors from the literature, the aircraft main engine PN emissions were estimated to change with a

  8. The proof and the pudding what mathematicians, cooks, and you have in common

    CERN Document Server

    Henle, Jim

    2015-01-01

    Tie on your apron and step into Jim Henle's kitchen as he demonstrates how two equally savory pursuits-cooking and mathematics-have more in common than you realize. A tasty dish for gourmets of popular math, The Proof and the Pudding offers a witty and flavorful blend of mathematical treats and gastronomic delights that reveal how life in the mathematical world is tantalizingly similar to life in the kitchen. Take a tricky Sudoku puzzle and a cake that fell. Henle shows you that the best way to deal with cooking disasters is also the best way to solve math problems. Or take an L-shaped billi

  9. The quality evaluation program for plutonium pits at the U.S. DOE Pantex plant.

    Science.gov (United States)

    Vickers, L; Eifert, E

    2000-11-01

    The United States Department of Energy Pantex Plant quality evaluation program for plutonium pits is an extensive program that includes 1) weigh and leak check system; 2) radiography; and 3) dye penetrant testing. Successful completion of these diagnostics qualifies a pit to remain in the active status stockpile program. The use of lead aprons and a robot when handling the plutonium pits minimizes personnel exposures to ionizing radiation. All personnel exposures to ionizing radiation at Pantex Plant are As Low As Reasonably Achievable. PMID:11045519

  10. Root parsley protection against damping off

    OpenAIRE

    Bogdan Nowicki

    2013-01-01

    Seed treatment ofroot parsley was done to protect Petroselinum santivum seedlings against damping off. Fungicides used as seed dressers were applied in 3 doses: 3, 5 and 10 g/kg. Seeds were treated with 7 dressers (Table l) used separately and in mixture with 3 g/kg of Rovral 50 WP (50% iprodione) and 1 g/kg of Apron 35 SD (35% metalaxyl). Two seed samples of Berlińska cultivar were used: first sample was strongly infected by Alternaria petroselini and A.radicina both 27,6% and also by Fusari...

  11. Dosimetric essay in dental radiology

    International Nuclear Information System (INIS)

    A neck study was observated in the tiroids glands,laryngeal zone, sensitive organs for the ionizing radiation for increase dental xray exams. Was selected 29th patients with radiography prescription complete (in the Odontology Faculty Clinics Uruguaian). It took radiographies with and without tiroids necklace and apron lead using dosemeters. Dosimetric studies had demonstrated good dose between patients. For measuring the radiation dose have been used TLD thermoluminescence dosimetric and Harshaw 6600 for read it. The thyroids necklace use and odontology postgrading for training course for dentistry was the two recommendations advised

  12. Modelling and Analysis of the Gobustan: Sundial Observatory

    Science.gov (United States)

    Rustamov, Abasali; Rustamova, Gunay

    2015-05-01

    The well-known boat carvings of Gobustan Rock Carvings Preserve with a crosses or strokes on board and sun image on the prow are calendrical inscriptions. Moreover, the "year boat" from eastern niche of Stone No.1 used in conjunction with a gnomon, to indicate solar time periods. The bull, ram, ibex and some time boat with the sinuous brook carved on the niche apron evidence relevant to the work zodiac creation. Decisive fact for this conclusion is the formation in the northern niche silhouette lion head, eating the sun in the summer.

  13. Language Policy and Minority Language Education in Nigeria: Cross River State Educational Experience

    OpenAIRE

    Roseline I. Ndimele

    2012-01-01

    The politics of language is a very sensitive issue in Nigeria as language can hardly be detached from the apron strings of the people’s senses of identity and loyalty. This paper examines the concept of language policy and planning in Nigeria and its implication for education in the minority languages, with emphasis on the languages of Cross River State. The study discovers that there is no robust and well-articulated language planning framework in the country but only a language provision of...

  14. Geologic Mapping of Ascraeus Mons, Mars

    Science.gov (United States)

    Mohr, K. J.; Williams, D. A.; Garry, W. B.

    2016-01-01

    Ascraeus Mons (AM) is the northeastern most large shield volcano residing in the Tharsis province on Mars. We are funded by NASA's Mars Data Analysis Program to complete a digital geologic map based on the mapping style. Previous mapping of a limited area of these volcanoes using HRSC images (13-25 m/pixel) revealed a diverse distribution of volcanic landforms within the calderas, along the flanks, rift aprons, and surrounding plains. The general scientific objectives for which this mapping is based is to show the different lava flow morphologies across AM to better understand the evolution and geologic history.

  15. Distribution and habitat utilization of the gopher tortoise tick (Amblyomma tuberculatum) in Southern Mississippi

    Science.gov (United States)

    Ennen, J.R.; Qualls, C.P.

    2011-01-01

    The distribution of the gopher tortoise tick (Amblyomma tuberculatum) has been considered intrinsically linked to the distribution of its primary host, gopher tortoises (Gopherus polyphemus). However, the presence of G. polyphemus does not always equate to the presence of A. tuberculatum. There is a paucity of data on the ecology, habitat preferences, and distribution of A. tuberculatum. The goals of this study were to assess the distribution of A. tuberculatum in southern Mississippi and to determine which, if any, habitat parameters explain the distribution pattern of A. tuberculatum. During 2006-2007, we examined 13 G. polyphemus populations in southern Mississippi for the presence of A. tuberculatum, and we measured a suite of habitat parameters at each site. Only 23% of the G. polyphemus populations supported A. tuberculatum, suggesting a more restricted distribution than its host. The results of our multivariate analyses identified several habitat variables, e.g., depth of sand and percentage of sand in the topsoil and burrow apron, as being important in discriminating between sites with, and without, A. tuberculatum. Amblyomma tuberculatum was only found at sites with a mean sand depth of >100 cm and a mean percentage of topsoil and burrow apron sand composition >94.0 and 92.4, respectively. Thus, environmental factors, and not just its host's range, seem to influence the distribution of A. tuberculatum. ?? American Society of Parasitologists 2011.

  16. Evaluation of radiological protection and dose of skin entrance in paediatric dentistry examinations; Avaliacao da protecao radiologica e da dose de entrada na pele em exames de odontologia pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Khoury, Helen Jamil [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Vasconcelos, Flavia Maria Nassar de [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Silveira, Marcia Maria Fonseca da [Universidade de Pernambuco (UPE), Recife, PE (Brazil). Fac. de Odontologia; Couto, Geraldo Bosco Lindoso [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Fac. de Odontopediatria; Brasileiro, Izabela Vanderley

    2005-07-01

    In this work the radiological protection conditions and dose at the entrance of pediatric patients undergoing dental intraoral radiographs were evaluated. The study was conducted in two clinics of the dentistry course at the Federal University of Pernambuco, Recife, PB, Brazil, equipped with conventional X-ray apparatus, with 60 and 70 kV. 254 exams of 113 patients between the ages of 3 to 12 years were evaluated. The skin entrance dose was estimated using TLD-100 thermoluminescent dosemeters. During the examination were also recorded information regarding the time of exposure, radiographic technique used, use of thyroid protectors and lead apron, angle and distance of the cone Locator to the patient's skin. The results showed that the input skin doses ranged from 0.3 mGy to 10mGy. The lead apron was used in 71% of exams while the thyroid shield was only used in 58% of the exams. The exposure times ranged from 0,5s to 1,5s. From the results it can be concluded that the radiological procedures are not optimized and that in some cases the patient dose is high.

  17. Modeling Mass Movements on Mars

    Science.gov (United States)

    Bulmer, M. H.; Glaze, L.; Barnouin-Jha, O.; Murphy, W.; Neumann, G.

    2002-05-01

    Slope failure and the resulting movement of material downslope on Mars has never been witnessed, making careful data analyses combined with physical modeling the only way to understand their emplacement process. Evidence exists for varying types of landsliding on Mars. They are a significant geomorphic agent in the modification of the surface of Mars and their emplacement style remains contentious. Furthermore, little is known about the slope forming materials and the processes that govern the triggering, failure, and deposition of landslides. We are examining the emplacement of a range of mass movement types in varying geologic settings on Mars by building on detailed landslide field and modeling studies we have conducted on Earth. We have identified a spectrum of different landslide types on Mars ranging from small gully failures such as those in Nirgal Vallis, lobate debris aprons, to large rock avalanches such as those in Ganges Chasma. The deposits associated with gullies and small debris aprons have characteristics analogous to alluvial fans, rock chutes, talus slopes, and debris flows on Earth. The large landslides on Mars have similar attributes to terrestrial rock avalanches and rockslides. Detailed studies on Earth have shown unique topographic and morphological differences between these mass movement types, which have been well documented and that we have examined. We are using Mars Global Surveyor (MGS) data to conduct new geomorphic, topographic and theoretical modeling studies on the emplacement of landslides on Mars at resolutions comparable to those on Earth.

  18. Technical knowledge assessment in radiology in patients protection in collective environments and more radiosensitive organs

    International Nuclear Information System (INIS)

    The use of X-rays in medical fields has increased significantly in recent years, since various therapeutic procedures can be performed without the need for surgery, which presents the greatest risk to the patient. An example of this increase is the practice of cardiac catheterization, this procedure fluoroscopy is used for placement of central venous catheters and temporary pacemakers, and long-term use increases the risk of exposure to X-rays to the patient, doctor and his assistants. This has been observed with concern by many researchers, since many companies did not fit the standards of radiation protection. This failure can lead to exposure of professionals, patients and caregivers. It is therefore of fundamental importance, the use of personal protective equipment such as aprons and thyroid plumbíferos protectors, for dose reduction produced by the primary and secondary radiation. This study evaluated the knowledge of radiology professionals in Goiânia, on the use of lead apron in collective environments and use of guards in sensitive parts of patients to radiation. Through an information gathering technique based on a questionnaire with closed questions. From dista and focuses on the knowledge of professionals. The results showed that there is a serious deficiency as regards the most radiosensitive organ protection of patients when they are exposed to X-ray beams. (author)

  19. Scatter radiation breast exposure during head CT: impact of scanning conditions and anthropometric parameters on shielded and unshielded breast dose

    Energy Technology Data Exchange (ETDEWEB)

    Klasic, B. [Hospital for pulmonary diseases, Zagreb (Croatia); Knezevic, Z.; Vekic, B. [Rudjer Boskovic Institute, Zagreb (Croatia); Brnic, Z.; Novacic, K. [Merkur Univ. Hospital, Zagreb (Croatia)

    2006-07-01

    Constantly increasing clinical requests for CT scanning of the head on our facility continue to raise concern regarding radiation exposure of patients, especially radiosensitive tissues positioned close to the scanning plane. The aim of our prospective study was to estimate scatter radiation doses to the breast from routine head CT scans, both with and without use of lead shielding, and to establish influence of various technical and anthropometric factors on doses using statistical data analysis. In 85 patient referred to head CT for objective medical reasons, one breast was covered with lead apron during CT scanning. Radiation doses were measured at skin of both breasts and over the apron simultaneously, by the use of thermo luminescent dosimeters. The doses showed a mean reduction by 37% due to lead shielding. After we statistically analyzed our data, we observed significant correlation between under-the-shield dose and values of technical parameters. We used multiple linear regression model to describe the relationships of doses to unshielded and shielded breast respectively, with anthropometric and technical factors. Our study proved lead shielding of the breast to be effective, easy to use and leading to a significant reduction in scatter dose. (author)

  20. Methodology of high dose research in medical radiodiagnostic; Metodologia de investigacao de doses elevadas em radiodiagnostico medico

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, Adriana E.; Martins, Cintia P. de S., E-mail: ird@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-11-01

    This work has as main purpose to study occupational exposure in diagnostic radiology in medical cases of high doses recorded in 2011 at the national level . These doses were recorded by monitoring individual of the occupationally exposed individuals (OEI's). This monitoring of the doses received by ionizing radiation has as main objective to ensure that the principle of dose limitation is respected. In this study it were evaluated doses of 372 OEI's radiology in different Brazilian states. Doses were extracted from the database of Sector Management Doses of the Institute for Radioprotection and Dosimetry - IRD/CNEN-RJ, Brazil. The information from the database provide reports of doses from several states, which allows to quantify statistically, showing those with the highest doses in four areas: dose greater than or equal to 20 mSv apron and chest and dose greater than or equal to 100 mSv apron and chest. The identification of these states allows the respective Sanitary Surveillance (VISA), be aware of the events and make plans to reduce them. This study clarified the required procedures when there is a record of high dose emphasizing the importance of using protective radiological equipment, dosimeter and provide a safety environment work by maintaining work equipment. Proposes the ongoing training of professionals, emphasizing the relevance of the concepts of radiation protection and the use of the questionnaire with their investigative systematic sequence, which will allow quickly and efficiently the success the investigations.

  1. Distribution and habitat utilization of the gopher tortoise tick (Amblyomma tuberculatum) in Southern Mississippi.

    Science.gov (United States)

    Ennen, Joshua R; Qualls, Carl P

    2011-04-01

    The distribution of the gopher tortoise tick ( Amblyomma tuberculatum ) has been considered intrinsically linked to the distribution of its primary host, gopher tortoises ( Gopherus polyphemus ). However, the presence of G. polyphemus does not always equate to the presence of A. tuberculatum . There is a paucity of data on the ecology, habitat preferences, and distribution of A. tuberculatum . The goals of this study were to assess the distribution of A. tuberculatum in southern Mississippi and to determine which, if any, habitat parameters explain the distribution pattern of A. tuberculatum . During 2006-2007, we examined 13 G. polyphemus populations in southern Mississippi for the presence of A. tuberculatum , and we measured a suite of habitat parameters at each site. Only 23% of the G. polyphemus populations supported A. tuberculatum , suggesting a more restricted distribution than its host. The results of our multivariate analyses identified several habitat variables, e.g., depth of sand and percentage of sand in the topsoil and burrow apron, as being important in discriminating between sites with, and without, A. tuberculatum. Amblyomma tuberculatum was only found at sites with a mean sand depth of > 100 cm and a mean percentage of topsoil and burrow apron sand composition > 94.0 and 92.4, respectively. Thus, environmental factors, and not just its host's range, seem to influence the distribution of A. tuberculatum. PMID:21506776

  2. Prevalence and Antibiotic Susceptibility of Salmonella species Isolated from Beef and its Related Samples in Techiman Municipality of Ghana

    Directory of Open Access Journals (Sweden)

    Frederick Adzitey

    2015-08-01

    Full Text Available Salmonella species are important foodborne pathogens that have been implicated in a number of foodborne outbreaks. A total of 240 beef and its related samples obtained from the Techiman Municipality of Ghana were screened using the conventional method in the Food and Drug Administration-Bacteriological Analytical Manual (FDA-BAM-USA. The overall prevalence of Salmonella species was 57.08%. The prevalence of Salmonella species ranged from 33.30% to 75.00% in the meat and its related samples (table, knife and apron, and 6.30% to 93.80% at the various meat sale points (locations where meat is sold. Prevalence of Salmonella species was significantly higher in meat (75.00%, table (60.00% and knife (60.00%, than apron (33.33%. The most contaminated meat sale point was Kenten and Main markets (93.75% and the least contaminated sale point was Sansema junction (6.25%. All the Salmonella species were susceptible to ciprofloxacin but resistant to vancomycin. Intermediate resistances occur for all the antibiotics except ciprofloxacin and vancomycin. The Salmonella species also exhibited 23 antibiotic resistant patterns with the pattern EVa (erythromycin and vancomycin being the commonest (exhibited by nine different isolates. Multiple antibiotic index (MAR index ranged from 0.11 to 0.67. This study revealed that beef and its related samples in Techiman markets are contaminated with Salmonella.

  3. Scatter radiation breast exposure during head CT: impact of scanning conditions and anthropometric parameters on shielded and unshielded breast dose

    International Nuclear Information System (INIS)

    Constantly increasing clinical requests for CT scanning of the head on our facility continue to raise concern regarding radiation exposure of patients, especially radiosensitive tissues positioned close to the scanning plane. The aim of our prospective study was to estimate scatter radiation doses to the breast from routine head CT scans, both with and without use of lead shielding, and to establish influence of various technical and anthropometric factors on doses using statistical data analysis. In 85 patient referred to head CT for objective medical reasons, one breast was covered with lead apron during CT scanning. Radiation doses were measured at skin of both breasts and over the apron simultaneously, by the use of thermo luminescent dosimeters. The doses showed a mean reduction by 37% due to lead shielding. After we statistically analyzed our data, we observed significant correlation between under-the-shield dose and values of technical parameters. We used multiple linear regression model to describe the relationships of doses to unshielded and shielded breast respectively, with anthropometric and technical factors. Our study proved lead shielding of the breast to be effective, easy to use and leading to a significant reduction in scatter dose. (author)

  4. Occupational exposure doses in interventional procedures in Bosnia and Herzegovina

    International Nuclear Information System (INIS)

    Monitoring of occupationally exposed workers in Bosnia and Herzegovina started in 1960's and it was interrupted in 1992. Dosimetry service resumed in 1999 when the International Atomic Energy Agency provided Radiation Protection Centre with Harshaw 4500 Thermoluminescence dosemeter (TLD)-reader and the first set of TLDs. The highest doses are received by professionals working in interventional procedures (radiology, cardiology, gastroenterohepatology etc.). Number of these procedures is increasing each year (just in cardiology this increase is 24 % per year). Results from two TLDs are used to estimate effective dose. One is worn under the apron (chest level), and the other above (neck level). Calculation is performed using Niklason's methodology. Total number of occupationally exposed persons in interventional radiology is 90. The collective dose they receive is 67 person mSv, while the mean dose is 0.77 mSv (based on 12-month period). Highest doses are received by physicians (3.7 mSv), while radiographers and nurses receive 2.1 and 1.9 mSv respectively. This occurs due to the fact that physicians stand closer to the source (patient). The lead apron is proven to be the most efficient radiation protection equipment, but, also, lead thyroid shield and glasses can significantly lower doses received by professionals. The use of this equipment is highly recommended. (authors)

  5. Utilização dos métodos de biossegurança nos consultórios odontológicos da cidade de Porto Alegre-RS

    Directory of Open Access Journals (Sweden)

    Lucas R. Galvani

    2004-01-01

    Full Text Available The infection control in dental offices became a big challenge to clinicians that act in dentistry. During clinical procedure, clinicians should use methods to avoid the risk of infection and cross-transmission. The purpose of this study was to verify in 445 dental-surgeons, randomly chosen, in the city of Porto Alegre (RS, whether they use the following methods of prevention: gloves, mask, protection glasses, apron, beret, or none of these. The obtained results were: 331 CDs are clinicians (70,33% and 132 are specialists (29,67%. From this, 433 use apron (97,30%, 387 use gloves (86,96%, 297 use mask (66,74%, 153 use protection glasses (34,38%, 12 did not use any kind of protection (2,7%, being 11 clinicians and 1 specialist. With such results, it´s important make up clinicians mind about the usage of methods that control the infection risks and cross-transmission mainly those graduated more than 10 years ago

  6. Microfacies analysis of the Upper Triassic (Norian) "Bača Dolomite": early evolution of the western Slovenian Basin (eastern Southern Alps, western Slovenia)

    Science.gov (United States)

    Gale, Luka

    2010-08-01

    The Slovenian Basin represents a Mesozoic deep-water sedimentary environment, situated on the southern Tethyan passive margin. Little is known about its earliest history, from the initial opening in the Carnian (probably Ladinian) to a marked deepening at the beginning of the Jurassic. The bulk of the sediment deposited during this period is represented by the Norian-Rhaetian "Bača Dolomite", which has, until now, been poorly investigated due to a late-diagenetic dolomitization. The Mount Slatnik section (south-eastern Julian Alps, western Slovenia) is one of a few sections where the dolomitization was incomplete. Detailed analysis of this section allowed us to recognize eight microfacies (MF): MF 1 (calcilutite), MF 2 (pelagic bivalve-radiolarian floatstone/wackestone to rudstone/packstone), MF 3 (dolomitized mudstone) with sub-types MF 3-LamB and MF 3-LamD (laminated mudstone found in a breccia matrix and laminated mudstone found in thin-bedded dolomites, respectively) and MF 3-Mix (mixed mudstone), MF 4 (bioturbated radiolarian-spiculite wackestone), MF 5 (fine peloidal-bioclastic packstone), MF 6 (very fine peloidal packstone), MF 7 (bioclastic wackestone) and MF 8 (crystalline dolomite). The microfacies and facies associations indicate a carbonate slope apron depositional environment with hemipelagic sedimentation punctuated by depositions from turbidites and slumps. In addition to the sedimentary environment, two "retrogradation-progradation" cycles were recognized, each with a shift of the depositional setting from an inner apron to a basin plain environment.

  7. Effect of Radiation Monitoring Method and Formula Differences on Estimated Physician Dose during Percutaneous Coronary Intervention

    Energy Technology Data Exchange (ETDEWEB)

    Chida, K.; Morishima, Y.; Masuyama, H.; Chiba, H.; Katahira, Y.; Inaba, Y.; Mori, I.; Maruoka, S.; Takahashi, S.; Kohzuki, M.; Zuguchi, M. (Dept. of Radiological Technology, School of Health Sciences, Faculty of Medicine, Tohoku Univ., Sendai (Japan))

    2009-02-15

    Background: Currently, one or two dosimeters are used to monitor radiation exposure in most cardiac laboratories. In addition, several different formulas are used to convert exposure data into an effective dose (ED). Purpose: To clarify the effect of monitoring methods and formula selection on the estimated ED for physicians during percutaneous coronary interventions (PCIs). Material and Methods: The ED of physicians during cardiac catheterization was determined using an optically stimulated luminescence dosimeter (Luxel badge). Two Luxel badges were worn: one beneath a personal lead apron (0.35-mm lead equivalent) at the chest and one outside of the apron at the neck. Results: The difference in the average ED of seven physicians was approximately fivefold (range 1.13-5.43 mSv/year) using the six different formulas in the clinical evaluation. The estimated physician ED differed markedly according to both the monitoring method and formula selected. Conclusion: ED estimation is dependent on both the monitoring method and the formula used. Therefore, it is important that comparisons among laboratories are based on the same monitoring method and same formula for calculating the ED

  8. Optimizing radiation protection of the operator during cardiac catheterization by minimizing the effective dose

    International Nuclear Information System (INIS)

    Radiation exposure dosimetry for the personnel is based on measurements of phantom studies. To determine effective dose values for different X-ray equipment, TLD-measurements were performed using an Alderson Phantom in the patient position and a second phantom in the typical position of the personnel. Various types of protective clothing as well as fixed shields were considered in the calculations. Additional thyroid protection collars reduce the effective dose by a factor of 1.8-2.6. In the sense of effective dose X-ray protective clothing with 0.35 mm lead equivalent and an additional thyroid protection collar provide a better protection against radiation than an apron with 0.5 mm lead equivalent without collar. The doses of the unshielded organs (thyroid, parts of the active bone marrow) contribute significantly to the effective dose of the staff. Therefore an additional shielding of these organs reduces the effective dose more than an increase of the lead equivalency of the existing apron. We recommend face shields and thyroid protection collars as a necessary part of anti-X protection for cardiac catherization laboratories. (author)

  9. Evaluation of radiological protection and dose of skin entrance in paediatric dentistry examinations

    International Nuclear Information System (INIS)

    In this work the radiological protection conditions and dose at the entrance of pediatric patients undergoing dental intraoral radiographs were evaluated. The study was conducted in two clinics of the dentistry course at the Federal University of Pernambuco, Recife, PB, Brazil, equipped with conventional X-ray apparatus, with 60 and 70 kV. 254 exams of 113 patients between the ages of 3 to 12 years were evaluated. The skin entrance dose was estimated using TLD-100 thermoluminescent dosemeters. During the examination were also recorded information regarding the time of exposure, radiographic technique used, use of thyroid protectors and lead apron, angle and distance of the cone Locator to the patient's skin. The results showed that the input skin doses ranged from 0.3 mGy to 10mGy. The lead apron was used in 71% of exams while the thyroid shield was only used in 58% of the exams. The exposure times ranged from 0,5s to 1,5s. From the results it can be concluded that the radiological procedures are not optimized and that in some cases the patient dose is high.

  10. Bacteriological Monitoring of Radiology Room Apparatus in the Department of Radiological Technology and Contamination on Hands of Radiological Technologists

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seon Chil [Dept. of Radiologic Technology, Daegu Health College, Daegu (Korea, Republic of)

    2008-12-15

    Distribution of microorganisms were examined for the bucky tables in the radiology rooms of the department of radiological technology, the aprons, handles of various apparatus, handles of mobile radiological apparatus, and hands of the radiological technologists. As a result, relatively larger amounts of bacteria were found on the handles of the mobile radiological apparatus and the aprons. Among the isolated bacteria, Acinetobacter baumanni (7.3%), Klebsiella pneumoniae (6.7%), Staphylococcus aureus (3.9%), Serratia liquefaciens (1.7%), Enterobacter cloaceae (0.6%), Providenica rettgeri (0.6%) are known as the cause of nosocomial infection (hospital acquired infection). In addition, similar colonies were also found on the hands of the radiological technologists such as microorganisms of Klebsiella pneumoniae (8.4%), Staphylococcus aureus (6.6%), Yersinia enterocolotica (5.4%), Acinetobacter baumanni (4.2%), Enterobacter cloaceae (2.4%), Serratia liquefaciens (1.8%), Yersinia pseuotuberculosis (18%), Enterobacter sakazakii (1.2%), and Escherichia coli (0.6%). In particular, this result indicates clinical significance since Staphylococcus aureus and Escherichia coli show strong pathogenicity. Therefore, a continuous education is essential for the radiological technologists to prevent the nosocomial infection.

  11. Bacteriological Monitoring of Radiology Room Apparatus in the Department of Radiological Technology and Contamination on Hands of Radiological Technologists

    International Nuclear Information System (INIS)

    Distribution of microorganisms were examined for the bucky tables in the radiology rooms of the department of radiological technology, the aprons, handles of various apparatus, handles of mobile radiological apparatus, and hands of the radiological technologists. As a result, relatively larger amounts of bacteria were found on the handles of the mobile radiological apparatus and the aprons. Among the isolated bacteria, Acinetobacter baumanni (7.3%), Klebsiella pneumoniae (6.7%), Staphylococcus aureus (3.9%), Serratia liquefaciens (1.7%), Enterobacter cloaceae (0.6%), Providenica rettgeri (0.6%) are known as the cause of nosocomial infection (hospital acquired infection). In addition, similar colonies were also found on the hands of the radiological technologists such as microorganisms of Klebsiella pneumoniae (8.4%), Staphylococcus aureus (6.6%), Yersinia enterocolotica (5.4%), Acinetobacter baumanni (4.2%), Enterobacter cloaceae (2.4%), Serratia liquefaciens (1.8%), Yersinia pseuotuberculosis (18%), Enterobacter sakazakii (1.2%), and Escherichia coli (0.6%). In particular, this result indicates clinical significance since Staphylococcus aureus and Escherichia coli show strong pathogenicity. Therefore, a continuous education is essential for the radiological technologists to prevent the nosocomial infection.

  12. Lower Permian Dry Mountain trough, eastern Nevada: preliminary basin analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, D.L.; Snyder, W.S.; Spinosa, C.

    1987-08-01

    The Lower Permian Dry Mountain trough (DMT) is one of several basins that developed during the Late Pennsylvanian to Permian along the western edge of the North American continent. A tectonic mechanism has been suggested for the subsidence of the DMT, possibly due to reactivation of the Antler orogenic belt during the waning stages of Ancestral Rocky Mountain deformation. The DMT records marked subsidence with the appearance during the Artinskian (latest Wolfcampian) of a deeper water facies that consists of thin-bedded silty micrites and micritic mudstones rich in radiolarians and sponge spicules, characterized by a relative abundance of ammonoids, and rarer conodonts and Nereites ichnofacies trace fossils. Taxa recovered from a distinctive concretionary horizon at various locations provide an Artinskian datum on which to palinspastically reconstruct the DMT paleogeography. These taxa include ammonoids: Uraloceras, Medlicottia, Marathonites, Crimites, Metalegoceras, properrinitids; and conodonts: Neogondolella bisselli, Sweetognathus whitei, S. behnkeni, and Diplognathodus stevensi. The western margin facies of the DMT consists of Permian Carbon Ridge/Garden Valley Formations. Here, lowermost black Artinskianage euxinic micrites, considered a potential source rock for petroleum generation, are overlain by base-of-slope carbonate apron deposits, which, in turn, are overlain by base-of-slope carbonate apron deposits, which, in turn, are overlain by a thick, eastwardly prograding conglomerate wedge. Seismic profiles across Diamond Valley indicate a 3.0-4.6-km thick Tertiary sequence above the Paleozoic strata.

  13. Dune field reactivation from blowouts: Sevier Desert, UT, USA

    Science.gov (United States)

    Barchyn, Thomas E.; Hugenholtz, Chris H.

    2013-12-01

    Dune field reactivation (a shift from vegetated to unvegetated state) has important economic, social, and environmental implications. In some settings reactivation is desired to preserve environmental values, but in arid regions reactivation is typically a form of land degradation. Little is known about reactivation due to a lack of published records, making modeling and prediction difficult. Here we detail dune reactivations from blowout expansion in the Sevier Desert, Utah, USA. We use historical aerial photographs and satellite imagery to track the transition from stable, vegetated dunes to actively migrating sediment in 3 locations. We outline a reactivation sequence: (i) disturbance breaches vegetation and exposes sediment, then (ii) creates a blowout with a deposition apron that (iii) advances downwind with a slipface or as a sand sheet. Most deposition aprons are not colonized by vegetation and are actively migrating. To explore causes we examine local sand flux, climate data, and stream flow. Based on available data the best explanation we can provide is that some combination of anthropogenic disturbance and climate may be responsible for the reactivations. Together, these examples provide a rare glimpse of dune field reactivation from blowouts, revealing the timescales, behaviour, and morphodynamics of devegetating dune fields.

  14. Architecture and facies pattern of a sublacustrine fan, Jharia Basin, India

    Science.gov (United States)

    Dasgupta, Prabir

    2002-05-01

    A small sublacustrine fan deposit has been identified within a lacustrine succession belonging to the Barren Measure Formation (Middle Permian) of the Lower Gondwana deposits of Jharia Basin, India. The stratigraphic position of the fan and its structural relationship with the associated sediments suggest that the east-west aligned elongate trough formed in the central part of the basin experienced intrabasinal normal faulting of limited lateral extent, and accumulation of clastic input within the associated hangingwall syncline led to formation of this deposit. Three major framework components can be identified within this deposit: (a) sheet-like sandstone aprons, (b) channel-fill sandbodies and (c) lensoid massive beds of pebbly sandstone. The laterally extensive sheet-like bodies of sandstone, covering almost the whole of the older sediments, appear to be the product of deposition from unconfined sediment-laden flows during episodic flood events. The proximal part of the deposit is dominated by the successive deposition of sandstone aprons with a few channel plug sandbodies produced through rapid sedimentation from channelised sediment-laden turbulent flows. The distal part, on the other hand, is mainly represented by the stacked channel-fills with alternate sandstone aprons. Following the deposition of bedded sandstones, as the slope of the depositional surface reduced, turbulent flows with relatively less grain concentration extended towards the ambient waterbody through channels incised into the preexisting unconsolidated sediments. During this process of incision, the flows gradually became hyperconcentrated. The channels were ultimately filled-in by concordant bedsets in approximate conformity with the shape of the channel, either through bedload deposition or suspension fall-out from these submerged currents. A few massive channel-fills, indicating emplacement of liquefied sandflows, caused by slope instability during high-flood event, are also present

  15. The Swedish Bohus granite - a stone with a fascinating history

    Science.gov (United States)

    Schouenborg, Björn; Eliasson, Thomas

    2015-04-01

    One of the most well-known and well spread Swedish stone types used as building stones is the Bonus granite. It outcrops in an area north of Gothenburgh (SW Sweden), along the coastline, approximately 35 km wide and 85 km long. The granite continues into Norway as the Iddefjord granite. The Bohus granite is one of Sweden's youngest granites. Isotopic dating shows that the magma cooled at about 920 M years ago and thus marking the end of the Sveconorwegian orogoney. It is a composite granite massif area with several granitic intrusions but with rather homogeneous mineralogy. However, colour and texture varies quite a lot and the colour ranges from red to reddish grey although some pure grey varieties occur sparsely. The grain size ranges from medium grained to coarse grained and even with some porphyric parts. Quarrying in an industrial scale started 1842. The merchant A C Kullgren opened the first quarry and produced stones for the construction of the 86 km long Trollhättan channel connecting lake Vänern and the Atlantic ocean in the SW Sweden The stone was used for constructing harbors and wharves along the channel. Several quarries opened in the late 1800 around 1870 - 1890 and the export increased steadily with deliveries to Germany, Denmark, Holland, England and even to South America. The stone industries in Bohuslän (Bohus county), at its peak in 1929, engaged around 7 000 employees. During the depression in 1930 almost all of them became unemployed. However, as a curiosity, production and export continued to Germany for construction of Germania, the future World capital city ("Welthauptstadt Germania"), planned by Adolf Hitler and Albert Speer. About 500 stone workers were kept employed for this project during the late thirties. Today several varieties are still produced: Evja/Ävja, Tossene, Brastad, Näsinge, Broberg, Nolby, Allemarken and Skarstad. However, the number of stone workers is far from that of the early 1900. The Swedish production is mainly

  16. Triassic deep-marine sedimentation in the western Qinling and Songpan terrane

    Institute of Scientific and Technical Information of China (English)

    MENG; QingRen; QU; HongJie; HU; JianMin

    2007-01-01

    Triassic sequences in both the western Qinling and Songpan terrane are composed mostly of deep-marine sediments. A detailed study was carried out on main sedimentary facies of Triassic successions, showing that they resulted from diverse sedimentary processes, such as submarine debris-flows, turbidity currents, bottom-flows, suspension fallout, and fluidized sediment flows. Debris-flows are dividable into two types, gravelly and sandy debris-flows, respectively, and the sandy debris-flow deposits make up considerable portion of the Triassic successions concerned. Turbidite is characterized by occurrence of normal grading, and the whole Bouma sequences, though widely developed, are not totally attributed to true turbidity currents. The non-graded Ta division is thought to originate from sandy debris flows, whereas the rest divisions result from low-density currents or from bottom-current modification if they contain sedimentary structures related to traction currents. Four types of facies associations are distinguished within Triassic deep-marine successions: massive and thick-bedded coarse-grained facies association, medium- and thick-bedded sandstone with interlayered fine-grained facies association, interlayered thin-bedded fine-grained facies association, and syn-sedimentary slump/breccia facies association. Spatial distribution of the different facies associations suggests that Lower Triassic sedimentation occurred primarily in continental slope, submarine channels, and base-of-slope aprons in the Hezuo-Jianzha region of the western Qinling, whereas the Middle Triassic consists mainly of sedimentary facies of base-of-slope aprons and submarine incised valleys. The counterparts in the Dangchang-Diebu region, in contrast, are characterized by platform carbonates. The shallow-marine carbonates evolved into deep-marine facies since the Ladinian, indicative of rapid drowning of the Carnian carbonate platform in Middle Triassic times. Depositional history of Lower

  17. Assessment of occupational exposure in New Zealand from personal monitoring records

    International Nuclear Information System (INIS)

    This paper assesses recent occupational exposures in New Zealand based on doses reported by the National Radiation Laboratory (NRL) monitoring film service. Beginning in 1996, doses reported to monitored groups by NRL have been entered in a data base which records for each measured film details such as wearing position, wearing period and assessed dose. Although all details have not been systematically provided, the data base offers the potential for assessing cumulated doses to monitored personnel. In such an assessment matters to be taken into account are the handling of incomplete data, the derivation of effective doses from reported doses, particularly when protective clothing is being worn, and the treatment of doses below reporting levels. Algorithms for relating reported doses for badges worn with or without protective aprons and for different badge wearing positions (collar, under apron, over apron) have been developed based on published effective dose to Hp(10) ratios. For a sample of 2844 persons continuously monitored for more than one year only 52 (1.8 %) received doses exceeding 1 mSv/y, and 77 % received no detectable exposure at all. No individual approached the dose limit of 20 mSv/y recommended by the ICRP, and only one individual accumulated more than 5 mSv/y. As observed in a review of occupational exposures 15 years ago the highest mean annual dose was recorded by industrial radiographers, although the current mean dose at 0.8 mSv is well below the 2.3 mSv (effective dose equivalent) found over 1984/85 when a greater volume of industrial work was being carried out within the country. Nuclear medicine workers were again in second position with 0.65 mSv/y, but this was also less than the 1.4 mSv mean annual dose found over 1984/85. With the growth in interventional radiology, cardiologists emerge as a group with significant collar exposures, and also nurses and medical radiation technologists working in theatres where such work is carried out may

  18. Depositional architecture and evolution of the Late Miocene slope channel-fan-system in the northeastern shelf-margin of South China Sea

    Science.gov (United States)

    Jiang, Jing; Lin, Changsong; Zhang, Zhongtao; Tian, Hongxun; Tao, Ze; Liu, Hanyao

    2016-04-01

    The Upper Miocene in the Pearl River Mouth Basin of northwestern shelf-margin of South China Sea Basin contains a series of slope channel - fan systems. Their depositional architecture and evolution are documented in this investigation based on an integrated analysis of cores, logs, and seismic data. Four depositional-palaeogeomorphological elements have been identified in the slope channel-fan systems as follows: broad, shallow and unconfined or partly confined outer-shelf to shelf-break channels; deeply incised and confined unidirectionally migrating slope channels; broad or U-shaped, unconfined erosional-depositional channels; frontal splays-lobes and nonchannelized sheets. The slope channels are mostly oriented NW-SE, which migrated unidirectionally northeastwards and intensively eroded almost the whole shelf-slope zone. The channel infillings are mainly mudstones, interbedded with siltstones. They might be formed by gravity flow erosion as bypassing channels. They were filled with limited gravity flow sediments at the base and mostly filled with lateral accretionary packages of bottom current deposits. At the end of the channels, a series of small-scale slope fans developed and coalesced into fan aprons along the base of the slope. The unconfined erosional-depositional channels at the upper parts of the fan-apron-systems display compound infill patterns, and commonly have concave erosional bases and convex tops. The frontal splays-lobes representing middle to distal deposits of fan-apron-systems have flat-mounded or gull-wing geometries, and the internal architectures include bidirectional downlap, progradation, and chaotic infillings. The distal nonchannelized turbidite sheets are characterized by thin-bedded, parallel to sub-parallel sheet-like geometries. Three major unconformities or obvious erosional surfaces in the channel-fan systems of the Upper Miocene are recognized, and indicate the falling of sea-level. The depositional architecture of sequences

  19. 盾构施工安全穿越禄口机场复合地层段的数值模拟与监测分析%Numerical Simulation and Monitoring Analysis of Shield Construction Passing Through Complex Stratum in Lukou Airport

    Institute of Scientific and Technical Information of China (English)

    陈秋鑫; 李俊才; 刘光臣; 刘松

    2014-01-01

    盾构施工过程中由于土体挖除、管片和二衬设置,将在穿越过程引起机场滑行道和停机坪沉降或隆起,对机场正常运营产生不利影响;通过优化盾构机施工参数,从而降低盾构下穿过程中对机场的不利影响。基于ABAQUS有限元法,建立南京至高淳城际快轨下穿禄口机场复合地层段的有限元模型,分析盾构法施工引起的机场停机坪及滑行道变形特征,最终沉降最大值约为11 mm,最大隆起值约为2 mm,同时得到盾构施工工作参数。对比实际施工监测数据,针对施工风险提出更安全的盾构施工参数。%Due to soil excavation, pipe segment and secondary-lining setting-up, settlement or upheaval of taxiway and parking apron in the airport is likely to be induced especially during the time when shield machine is passing through under the airport, which adversely affects the normal operation of the airport. In this paper, shield construction parameters are adjusted to reduce the adverse effects towards the parking apron and the taxiway. Finite element model of intercity fast track between Nanjing and Gaochun passing through the complex stratum where the Lukou airport is located is established with ABAQUS software. The deformation of the parking apron and the taxiway caused by the construction is analyzed and the data show that the max sedimentation value is 11mm, while the max uplift value is 2mm. Meanwhile, operating parameters of the construction are obtained. Compared with the actual monitoring data, some safer shield construction parameters are recommended against construction risks.

  20. Quantification of microbial populations associated with the manufacture of vacuum-packaged, smoked vienna sausages.

    Science.gov (United States)

    Dykes, G A; Cloete, T E; von Holy, A

    1991-08-01

    Sources of contamination of vacuum-packaged vienna sausages by spoilage microorganisms were examined in a meat-processing plant. Microbial numbers present in the environment, on working surfaces and workers' hands and aprons were quantified by plate counting on selective media. Product line samples were taken at critical control points in the manufacturing process and analysed before and after preliminary incubation of vacuum-packaged samples at 25 degrees C for 24 h. In all samples the numbers of aerobic bacteria, Enterobacteriaceae, lactic acid bacteria and yeasts were determined by standard procedures. Contamination of sausage surfaces by lactic acid bacteria occurred as a result of the manufacturing and handling processes. The environment and specifically packers' hands, as well as working surfaces contributed to microbiological contamination of various types after removal of the peel from individual sausages. The preliminary incubation procedure allowed detection of low numbers of spoilage microorganisms. PMID:1911080

  1. Digital radiographic equipment in the Belgian dental office.

    Science.gov (United States)

    Gijbels, F; Debaveye, D; Vanderstappen, M; Jacobs, R

    2005-01-01

    A survey was performed among Belgian dentists to evaluate the use and management of digital radiographic equipment. The majority of respondents work as general dental practitioners. One out of eight sets of equipment for extraoral exposures is digital. For intraoral radiography, 30% of the equipment is digital. While exposure time is reduced by about 50% for digital intraoral radiography compared with conventional radiography, no differences can be found between different conventional film speed classes. Appropriate collimation of the radiation beam is only sparingly used. Beam aiming devices to hold the film and position the radiation beam are not used by the majority of dentists. While 25% of the respondents stand behind a protective wall during exposure, 8% of dentists remain next to the patient during exposure while assisting in holding the film inside the mouth. A minority of the latter practitioners wear lead aprons. PMID:16461489

  2. Crestal unconformities on an exposed Jurassic tilted fault block, Wollaston Forland, East Greenland as an analogue for buried hydrocarbon traps

    DEFF Research Database (Denmark)

    Surlyk, Finn; Korstgård, J.

    2013-01-01

    -rift unconformities. Crestal ridges are important elements in basin evolution, as they form drainage divides and sediment sources for aprons along footwall scarps and hangingwall deltas. A Middle Jurassic – lowermost Cretaceous footwall crest is exceptionally well exposed in the mountain Stratumbjerg in Wollaston...... Forland, East Greenland. Rifting and block tilting was initiated in the (?)Bajocian, intensified in the Oxfordian–Kimmeridgian, culminated in latest Jurassic, Volgian, time and faded out in the earliest Cretaceous. The main border faults of the westward tilted blocks trend roughly N–S. The first early syn......-rift block was formed in the Middle–Late Jurassic and was 40 km wide. During rift climax in the latest Jurassic it was fragmented into three blocks, each 10–15 km wide. The early syn-rift succession rests on thin Upper Permian evaporites and carbonates or directly on peneplaned crystalline basement. It is...

  3. Determination of effective dose for workers hemodynamics service using double dosimetry; Determinacion de la dosis efectiva para los trabajadores del servicio de hemodinamica usando doble dosimetria

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Lopez, M. A.; Lobato Munoz, M.; Jodar Lopez, C. A.; Ramirez Ros, J. C.; Jerez Sainz, M. I.; Pamos Urena, M.; Carrasco Rodriguez, J. L.

    2013-07-01

    The use of an additional dosimeter at the level of the neck above the lead apron we can provide an indication of the dose in the head (the Crystal dose). In addition, it is possible to combine the two readings of the dosimeter to provide an improved estimate of the effective dose. In the hemodynamics service of our Hospital we have maintained a worker for 3 years with the double dosimetry read monthly. With the readings from these dosimeters will do following algorithms, several estimates of the effective dose to see if, with working conditions that occur in this service, it would be necessary to extend this practice to the rest of the workers to get a better estimation of effective dose. (Author)

  4. Effective dose evaluation for workers assisting new-borns in nuclear medicine procedures

    International Nuclear Information System (INIS)

    Renal scintigraphy is a very frequent nuclear medicine procedure for new-borns when deemed necessary after prenatal ultrasounds investigation. The procedure requires the physical proximity of workers to the patient, particularly during the examination of new-borns, in order to keep the young patients still. The irradiation of nurses during kidney examination of new-borns has been measured by simulating the examination procedure with an Alderson Rando phantom stuffed with thermoluminescent detectors, positioned near a radioactive source obtained with a tank filled with a 99mTc solution. Measurements have been carried out both with and without radiation protection devices positioned on the Rando phantom. Different organ doses have been evaluated. The aim of this analysis is to evaluate the amount of dose reduction that can be achieved by utilising lead aprons, glasses and thyroid collars

  5. Climate change and coasts

    International Nuclear Information System (INIS)

    The investigation of climatic processes and behaviour examines the effects of climatic changes on human beings and the surrounding environment. The authors discuss, in a wide-subject perspective, the regional impacts of the greenhouse effect, increase of the sea level, and changed conditions of both precipitation and wind using the North and Baltic Sea as examples. In this effort, questions dealing with changes of water level, motion and (disturbance) of the sea and morphodynamic in the coastal apron, in reference to requirements on a future protection of the shore, are handled. In addition, not only the aspects of ecosystem-orientated adaption in the strip of land between the continent northern islands 'Wattenmeer' and ground landscape (Bodenlandschaft) are taken into consideration, but also the impact of these on human beings and their interest to use the coastal regions. (orig.). 102 figs., 9 tabs

  6. Radiation safety consideration during intraoperative radiation therapy

    International Nuclear Information System (INIS)

    Using in-house-designed phantoms, the authors evaluated radiation exposure rates in the vicinity of a newly acquired intraoperative radiation therapy (IORT) system: Axxent Electronic Brachytherapy System. The authors also investigated the perimeter radiation levels during three different clinical intraoperative treatments (breast, floor of the mouth and bilateral neck cancer patients). Radiation surveys during treatment delivery indicated that IORT using the surface applicator and IORT using balloons inserted into patient body give rise to exposure rates of 200 mR h-1, 30 cm from a treated area. To reduce the exposure levels, movable lead shields should be used as they reduce the exposure rates by >95 %. The authors' measurements suggest that intraoperative treatment using the 50-kVp X-ray source can be administered in any regular operating room without the need for radiation shielding modification as long as the operators utilise lead aprons and/or stand behind lead shields. (authors)

  7. An observation study of radiation exposure to nurses during interventional radiology procedure

    International Nuclear Information System (INIS)

    The purpose of this study was to prospectively measure the level of radiation exposure among nursing staff during interventional radiology procedures. All interventional radiology procedures performed at our institution between April 20 and June 19, 2009 were included in this study. Radiation exposure was measured as the equivalent dose penetrating tissue to a depth of 10 mm using electronic personal dosimeters attached outside (Ha) and inside (Hb) lead aprons. Effective dose (HE) was estimated by calculating from Ha and Hb. In total, data from 68 procedures were included in this study. Four nurses performed 71 nursing cares. The mean Ha was 0.70±1.0 μSv, while the mean Hb was 0.06±0.2 μSv. The mean HE was 0.14±0.3 μSv. The present findings indicate that during interventional radiology procedures, nurses were exposed to very low levels of radiation. (author)

  8. Determination of effective dose for workers hemodynamics service using double dosimetry

    International Nuclear Information System (INIS)

    The use of an additional dosimeter at the level of the neck above the lead apron we can provide an indication of the dose in the head (the Crystal dose). In addition, it is possible to combine the two readings of the dosimeter to provide an improved estimate of the effective dose. In the hemodynamics service of our Hospital we have maintained a worker for 3 years with the double dosimetry read monthly. With the readings from these dosimeters will do following algorithms, several estimates of the effective dose to see if, with working conditions that occur in this service, it would be necessary to extend this practice to the rest of the workers to get a better estimation of effective dose. (Author)

  9. Endoscopy dose examinations at the Sao Paulo University Hospital

    International Nuclear Information System (INIS)

    During some specific endoscopic examinations, radiographic and fluoroscopic images of patients are taken with the medical staff near to them. To evaluate the equivalent and effective doses in these occupational exposures, simulated examinations have been performed, using an anthropomorphic phantom in place of one of the members of the staff. Thermoluminescent dosimeters were attached in various positions of the phantom in order to determine some organ doses. From the comparison between the experimentally determined doses the International and the Brazilian recommended occupational dose limits, the maximum number of examinations that any member of the staff can perform, was calculated. If a protective apron is used, this number is limited by the high equivalent dose to the eye lens (average of 1.67 mSv/examination) of the staff's member. (authors). 3 refs., 4 tabs

  10. Radiation doses for X-ray diagnosis teeth in dental medicine

    International Nuclear Information System (INIS)

    X-rays are the first ionizing radiation, which are applied in medicine for diagnostic radiology and X-ray therapy. While in the beginning they are mainly used for X-ray photos of the chest /lungs and in severe fractures of the limbs, then in recent years they are widely applied in diagnostics of teeth in dental medicine. Considering that caries is a widespread disease, both in children and adults, and it requires repeated x-ray photographs of the damaged teeth for the individual, the total radiation doses, which reflect on people from the X-rays are at high values. In order to reduce external exposure to other organs /mainly thyroid gland/ by X-ray pictures of teeth, it should be used with special lead aprons with large coefficient of reduction. Keywords: doses of radiation, X-ray machines, dental, x-ray pictures of teeth, protection sources

  11. Lahar hazards at Agua volcano, Guatemala

    Science.gov (United States)

    Schilling, S.P.; Vallance, J.W.; Matías, O.; Howell, M.M.

    2001-01-01

    At 3760 m, Agua volcano towers more than 3500 m above the Pacific coastal plain to the south and 2000 m above the Guatemalan highlands to the north. The volcano is within 5 to 10 kilometers (km) of Antigua, Guatemala and several other large towns situated on its northern apron. These towns have a combined population of nearly 100,000. It is within about 20 km of Escuintla (population, ca. 100,000) to the south. Though the volcano has not been active in historical time, or about the last 500 years, it has the potential to produce debris flows (watery flows of mud, rock, and debris—also known as lahars when they occur on a volcano) that could inundate these nearby populated areas.

  12. A correlation study of eye lens dose and personal dose equivalent for interventional cardiologists

    International Nuclear Information System (INIS)

    This paper presents the dosimetry part of the European ELDO project, funded by the DoReMi Network of Excellence, in which a method was developed to estimate cumulative eye lens doses for past practices based on personal dose equivalent values, Hp(10), measured above the lead apron at several positions at the collar, chest and waist levels. Measurement campaigns on anthropomorphic phantoms were carried out in typical interventional settings considering different tube projections and configurations, beam energies and filtration, operator positions and access routes and using both mono-tube and biplane X-ray systems. Measurements showed that eye lens dose correlates best with Hp(10) measured on the left side of the phantom at the level of the collar, although this correlation implicates high spreads (41 %). Nonetheless, for retrospective dose assessment, Hp(10) records are often the only option for eye dose estimates and the typically used chest left whole-body dose measurement remains useful. (authors)

  13. Survey of radiologic practices among dental practitioners

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the factors that influence and contribute to patient exposure in radiologic procedures performed in the offices of 132 staff members within the dental department of a teaching hospital. A questionnaire was prepared in which data were requested on brands of film used, type of x-ray unit used, processing, and use of leaded apron, cervical shield, and film holder. Offices were also visited to evaluate performance of existing dental x-ray equipment. Both the Dental Radiographic Normalizing and Monitoring Device and the Dental Quality Control Test Tool were evaluated. The average exposure was equivalent to the class D film (220 mR), but only 13% of those surveyed used the faster class E film, which would reduce patient exposure in half. The survey indicates that dentists are not using the newer low-exposure class E film in their practices

  14. Medical dosimetry in Hungary

    Science.gov (United States)

    Turák, O.; Osvay, M.; Ballay, L.

    2012-09-01

    Radiation exposure of medical staff during cardiological and radiological procedures was investigated. The exposure of medical staff is directly connected to patient exposure. The aim of this study was to determine the distribution of doses on uncovered part of body of medical staff using LiF thermoluminescent (TL) dosimeters in seven locations. Individual Kodak film dosimeters (as authorized dosimetry system) were used for the assessment of medical staff's effective dose. Results achieved on dose distribution measurements confirm that wearing only one film badge under the lead apron does not provide enough information on the personal dose. The value of estimated annual doses on eye lens and extremities (fingers) were in good correlation with international publications.

  15. Paleomagnetism of San Cristobal Island, Galapagos

    Science.gov (United States)

    Cox, A.

    1971-01-01

    Isla San Cristobal, the most easterly of the Galapagos Islands, consists of two parts: a large volcano constitutes the southwest half of the island and an irregular apron of small cones and flows makes up the northeast half. As some of the younger flows on the flanks of the large volcano are reversely magnetized, the minimum age of the volcano is 0.7 my, which is the age of the Brunhes-Matuyama reversal boundary. The true age is probably several times greater. The cones and flows to the northeast are all normally magnetized. The between-site angular dispersion of virtual poles is 11.3?? - a value consistent with mathematical models for the latitude dependence of geomagnetic secular variation. ?? 1971.

  16. Evaluation of the use of personal protective equipment in radiodiagnostic services in Sergipe

    International Nuclear Information System (INIS)

    The theme ionizing radiation is frequently associated with danger. Therefore this subject induces to think about accessories to personal protection. These accessories can contain metal heavy (as example, lead) so that we have an efficient protection. Our analysis was done with the main objective of evidence that is not enough the radiodiagnostic services have personal protective equipment to disposal to the radiology technicians have an efficient protection, because the procedures with ionizing radiation will be safe only with the use accomplish of the security procedures and of adequate use and storing of personal protective equipment. In our analysis the accessories in question were the lead rubber X-ray protection aprons and thyroid gland protectors. We have tested these accessories through of a similar methodology utilized to checking the half-value layer of the X-ray units. It was investigated also the importance given to use of these accessories by the radiology technicians. (author)

  17. Radiation protection in interventional radiology

    International Nuclear Information System (INIS)

    The application of ionizing radiation in medicine seems to be a safe procedure for patients as well as for occupational exposition to personnel. The developments in interventional radiology with fluoroscopy and dose-intensive interventions require intensified radiation protection. It is recommended that all available tools should be used for this purpose. Besides the options for instruments, x-ray protection at the intervention table must be intensively practiced with lead aprons and mounted lead glass. A special focus on eye protection to prevent cataracts is also recommended. The development of cataracts might no longer be deterministic, as confirmed by new data; therefore, the International Commission on Radiological Protection (ICRP) has lowered the threshold dose value for eyes from 150 mSv/year to 20 mSv/year. Measurements show that the new values can be achieved by applying all X-ray protection measures plus lead-containing eyeglasses. (orig.)

  18. Conditions of radiation protection in medical stations

    International Nuclear Information System (INIS)

    The purpose of this study is to clear up what safety procedures are normally' observed for occupational and environmental radiology. 30 Public Medical station in Rio de Janeiro were investigated. A questionaire of 13 questions was prepared to be filled up by the professionals directly involved with the radiologic work, intending to evaluate, the personal and environmental aspect of radioprotection, the individual responsability of each worker and of the whole institution. It was also verified that knowledge of safety norms is doubtful and precarious in the despite of the fact that a great number of the people in question declare to have specific graduation for the activity. Only 45% from the total really make use of the dosimeters, the periodical medical examinations are not frequent (65%), and fewer employes make use of this lead apron (23%). We come to the conclusion that there is a remarkable bewilderment as for the personal observences about the work conditions in controlled areas. (author)

  19. Radiation protection of personnel and operators in interventional radiology

    International Nuclear Information System (INIS)

    The interventional radiology room is in controlled area. The operators and paramedical people are classified in A category. The operators are the most exposed. The pregnancy is a contraindication for the work in this sector. The radiation protection means are the work station quality (the installation must allow to position the X radiation tube under the table), the optimization of the exposure time, the wearing of leaded accessory (glasses, apron), the training and the information. The obligatory surveillance of the personnel exposure associates the monthly passive dosimetry and the active dosimetry. A dosimetry of extremities can complete the operators follow-up. A worker cannot be affected in this sector without a preliminary medical examination. (N.C.)

  20. The evaluation of mine geology disasters based on fuzzy mathematics and grey theory

    Institute of Scientific and Technical Information of China (English)

    L(U) Da-wei; WU Li-rong; LI Zeng-xue

    2007-01-01

    Mine geology disasters include mine water, mine solid waste, apron and slide,ground collapse sink and underground fracture, etc.. The subject was studied in many ways, and fuzzy mathematics was usually used. It may assure the result and distinguish the dangerous rank of different areas. But it has two defects: The first is the result is not very exact, especially the border; The second is it is short of quantity. Fuzzy mathematics and grey theory were used in order to solve the problem. Firstly, mathematical model was constructed by using grey theory, so as to evaluate and forecast the dangerous rank of mining geology disaster in different areas. Then different areas were analyzed and divided by fuzzy mathematics. By doing these, similitude rules are not only studied but also differences are discriminated. Through the practice it can be known that the result is more accurate than before.

  1. Seasonal erosion and restoration of Mars' northern polar dunes.

    Science.gov (United States)

    Hansen, C J; Bourke, M; Bridges, N T; Byrne, S; Colon, C; Diniega, S; Dundas, C; Herkenhoff, K; McEwen, A; Mellon, M; Portyankina, G; Thomas, N

    2011-02-01

    Despite radically different environmental conditions, terrestrial and martian dunes bear a strong resemblance, indicating that the basic processes of saltation and grainfall (sand avalanching down the dune slipface) operate on both worlds. Here, we show that martian dunes are subject to an additional modification process not found on Earth: springtime sublimation of Mars' CO(2) seasonal polar caps. Numerous dunes in Mars' north polar region have experienced morphological changes within a Mars year, detected in images acquired by the High-Resolution Imaging Science Experiment on the Mars Reconnaissance Orbiter. Dunes show new alcoves, gullies, and dune apron extension. This is followed by remobilization of the fresh deposits by the wind, forming ripples and erasing gullies. The widespread nature of these rapid changes, and the pristine appearance of most dunes in the area, implicates active sand transport in the vast polar erg in Mars' current climate. PMID:21292976

  2. Radiation dose to personnel during percutaneous renal calculus removal

    International Nuclear Information System (INIS)

    Radiation dose to the radiologist and other personnel was measured during 102 procedures for percutaneous removal of renal calculi from the upper collecting system. A mobile C-arm image intensifier was used to guide entrance to the kidney and stone removal. Average fluoroscopy time was 25 min. Exposure to personnel was monitored by quartz-fiber dosimeters at the collar level above the lead apron. Average radiation dose to the radiologist was 10 mrem (0.10 mSv) per case; to the surgical nurse, 4 mrem (0.04 mSv) per case; to the radiologic technologist, 4 mrem (0.04 mSv) per case; and to the anesthesiologist, 3 mrem (0.03 mSv) per case. Radiation dose to the uroradiologic team during percutaneous nephrostolithotomy is similar to that from other interventional fluoroscopic procedures and is within acceptable limits for both physicians and assisting personnel

  3. Radiation dose to personnel during percutaneous renal calculus removal

    Energy Technology Data Exchange (ETDEWEB)

    Bush, W.H.; Jones, D.; Brannen, G.E.

    1985-12-01

    Radiation dose to the radiologist and other personnel was measured during 102 procedures for percutaneous removal of renal calculi from the upper collecting system. A mobile C-arm image intensifier was used to guide entrance to the kidney and stone removal. Average fluoroscopy time was 25 min. Exposure to personnel was monitored by quartz-fiber dosimeters at the collar level above the lead apron. Average radiation dose to the radiologist was 10 mrem (0.10 mSv) per case; to the surgical nurse, 4 mrem (0.04 mSv) per case; to the radiologic technologist, 4 mrem (0.04 mSv) per case; and to the anesthesiologist, 3 mrem (0.03 mSv) per case. Radiation dose to the uroradiologic team during percutaneous nephrostolithotomy is similar to that from other interventional fluoroscopic procedures and is within acceptable limits for both physicians and assisting personnel.

  4. Hydrothermal alteration at the Roosevelt Hot Springs thermal area, Utah: characterization of rock types and alteration in Getty Oil Company well Utah state 52-21

    Energy Technology Data Exchange (ETDEWEB)

    Ballantyne, G.H.

    1978-11-01

    Getty Oil Company well 52-21 in the Roosevelt Hot Springs thermal area was drilled to 7500 feet in predominantly upper amphibolite facies metamorphic rocks. All lithologies in the drill hole are pervasively but weakly altered: the alteration assemblage is chlorite + sericite + clays with occasional traces of calcite, above 2300 feet, and chlorite + sericite + clays + calcite +- epidote below 2500 feet. A zone of increased alteration intensity from approximately 1800 feet to 2300 feet occurs within and adjacent to a dacite dike which cuts the metamorphic rocks. A second zone of stronger alteration extends from 6000 feet to the bottom of the drill hole. The drill hole which is located approximately 5000 feet south of the center of the silica apron known as the Opal Mound was apparently drilled beyond the influence of acid, high-sulfate brines such as have affected the upper portions of drill holes 72-16, 76-1 and University of Utah 1A and 1B.

  5. Radical abdominoplasty, including body shaping: representative cases.

    Science.gov (United States)

    Mühlbauer, W

    1989-01-01

    Even in the age of liposuction there exist certain situations for which abdominoplasty in its radical form is indicated--for example, redundant skin after radical weight loss, the stigmata of postpregnancy syndrome, and localized accumulation of adipose tissue--the lipodystrophies and resistant generalized obesity. Redundant skin after radical weight loss is resected simultaneously around the abdomen, the lumbar regions, the perineum, and the thighs. The typical stigmata of postpregnancy syndrome may be excised through an extended abdominoplasty combined with simultaneous excision and pexy of the inner aspects of the thighs leaving a "bikini" scar behind. A mastopexy may be added. Genetically predisposed localized lipodystrophies in the abdominal lumbar, and upper thigh region may be resected through a circular abdominoplasty with or without simultaneous resection of the perineum and inner thighs. Abdominal aprons often contain umbilical or ventral hernias that may need to be repaired simultaneously. Representative cases are presented and dangers and complications are discussed. PMID:2741749

  6. A History of the Danubian Costume in the XIXth Century

    Directory of Open Access Journals (Sweden)

    Cristina Partenie

    2013-08-01

    Full Text Available Nowadays we attach a great importance to the clothes we wear from the moment we buy or make them, to the moment we decide if they are appropriate with our personal style, the place where we wear them or when we use them. If the XIXth century tries to preserve the tradition with great accuracy the way it was transmitted from generation to generation, in the tumultuous XXth century we attend to the birth of a real industry of fashion. Some reminiscences remain, however, which gives us the opportunity to draw up a study in this regard. The present paper intends to add information regarding the folk costumes in Galati County, especially in the XIXth century. It is a short presentation of some of the most traditional clothes such as: skirt, apron, hood, shirt male and shirt female, decorative designs, footwear; without claiming to have finished the subject we intend to go on with further research.

  7. Dose computation algorithms for individual thermoluminescence dosimetry

    International Nuclear Information System (INIS)

    Dose computation algorithms have been developed for interpretation of the TL readings obtained from three CaSO4:Dy-Teflon dosemeters positioned in the presently used TLD badge, in terms of equivalent dose. Algorithms are based on parametrization of the response to the various pure and mixed fields. It identifies the radiation field type, position of the badge during use i.e. above or below the lead apron and provide the equivalent dose making use of the appropriate correction factors. These algorithms have been successfully tested for routine personnel dosimetry and will be of great advantage with the TL reading system being coupled with PC for envisaged automation in large scale personnel monitoring programme. (author). 4 refs

  8. Active electronic personal dosemeter in interventional radiology

    International Nuclear Information System (INIS)

    A recently developed active electronic personal dosemeter (AEPD) was utilised in order to measure the levels and the structure of occupational exposure to scattered X-ray radiation of medical staff who performed percutaneous revascularisation therapy that involves interventional radiology (IR) on the pelvis and upper leg arteries. The AEPDs, placed on the operators' and assistants' chests, that is, above the protective apron, continuously measured and recorded the received doses and, as a novelty, dose rates as a function of time, thus yielding a unique record of occupational doses and dose rates pattern at the working place. This paper presents and discusses one typical daily pattern in which seven percutaneous interventions were performed. (authors)

  9. Ichnology of Upper Cretaceous deep-sea thick-bedded flysch sandstones: Lower Istebna Beds, Silesian Unit (Outer Carpathians, southern Poland)

    Science.gov (United States)

    Rajchel, Jacek; Uchman, Alfred

    2012-04-01

    The Ophiomorpha rudis ichnosubfacies of the Nereites ichnofacies was recognized in thick- and very thick-bedded sandstones of the Lower Istebna Beds (Campanian-Maastrichtian), which were deposited mainly in deep-sea clastic ramps and aprons. It contains mainly Ophiomorpha rudis (produced by deeply burrowing decapod crustaceans) and rarely Zoophycos isp. and Chondrites isp. The impoverished Paleodictyon ichnosubfacies of the Nereites ichnofacies is present in the medium- and thin-bedded packages of flysch sandwiched between the thick- and very thick-bedded sandstones. They contain Chondrites isp., Phycosiphon incertum, Planolites isp., Arthrophycus strictus, Thalassinoides isp., Ophiomorpha annulata, O. rudis, Scolicia strozzii and Helminthorhaphe flexuosa. The relatively low diversity of this assemblage is influenced by limited areas covered by muddy substrate, which favours deep-sea tracemakers, and partly by a lowered oxygenation in the sediment.

  10. Thermoluminescent dosimetry in veterinary diagnostic radiology

    International Nuclear Information System (INIS)

    This paper presents the results of Environmental and Personnel Dosimetry made in a radiology area of a veterinary hospital. Dosimetry was realized using thermoluminescent (TL) materials. Environmental Dosimetry results show that areas closer to the X-ray equipment are safe. Personnel Dosimetry shows important measurements of daily workday in some persons near to the limit established by ICRP. TL results of radiation measurement suggest TLDs are good candidates as a dosimeter to radiation dosimetry in veterinary radiology. - Highlights: ► Personnel dosimetry in laboratory veterinary diagnostic was determined. ► Student workplaces are safe against radiation. ► Efficiency value of apron lead was determined. ► X-ray beams distribution into veterinarian laboratory was measured.

  11. Radiation exposure of an anaesthesiologist in catheterisation and electrophysiological cardiac procedures.

    Science.gov (United States)

    Andreoli, Stefano; Moretti, Renzo; Lorini, Ferdinando Luca; Lagrotta, Mariavittoria

    2016-01-01

    Sometimes, cardiac catheterisation and electrophysiological procedures, diagnostic and interventional, require an anaesthesiological support. The anaesthesiologist receives radiation doses depending on various factors, such as type of procedure and exposure modality, anaesthesiological technique, individual protective devices and operator experience. The aim of this study was to investigate the dose per procedure, the exposure inhomogeneity and the effective dose, E, of a senior anaesthesiologist in the haemodynamic laboratory of Ospedali Riuniti, Bergamo. The dose monitoring was routinely performed with sets of several thermoluminescent dosemeters and an electronic personal dosemeter. The study covered 300 consecutive procedures over 1 y. The anaesthesiologist wore a protective apron, a thyroid collar and glasses (0.5 mm lead-equivalent). PMID:25752757

  12. Operational Radiation Protection in veterinary centres

    International Nuclear Information System (INIS)

    Nowadays, there is a trend towards the use of digital radiography in the veterinary field. As a consequence, there could be a workload increase in the X-ray system and higher exposure for veterinarians and members of the public. In this study we analyze the influence of the X-ray machine output with with the radiation levels at the veterinarian position. We have considered the leads apron that each veterinarian center has and we have related its attenuation coefficient with the dose exposure at the veterinarian position. With the maximum workload, we have made a theoretical assessment for the primary barrier at 1 m of the X-ray focus.Despite there is a workload increase due to the digital technologies, the studied results show that is is very unlikely to be in excess of annual dose limit for the exposed workers. (Author) 5 refs.

  13. Estimating effective dose for a cardiac catheterisation procedure with single or double personal dosemeters

    International Nuclear Information System (INIS)

    In most countries of the European Union legislation requires individual determination and registration of the dose to radiological workers exposed to ionising radiation to check whether dose limits are exceeded. To assess stochastic risk, ideally effective dose (E) should be known. In practice, personal dose equivalent [Hp(10)] is used as it can be measured with a personal dosemeter. The dosemeter reading may provide a reasonable assessment of Hp(10), but it may deviate strongly from E, in particular in radiology procedures for medical diagnosis or intervention when protective clothing like lead-equivalent apron and thyroid collar is worn. In the literature various correction factors and algorithms to convert readings of single or dual dosemeters to an estimate of E can be found. An illustrative example of a cardiac catheterisation procedure, in which dose calculations are made by Monte Carlo simulation of radiation transport, shows that such corrections may still yield considerable overestimation. (authors)

  14. Syn-rift unconformities punctuating the lower-middle Cambrian transition in the Atlas Rift, Morocco

    Science.gov (United States)

    Álvaro, J. Javier; Ezzouhairi, Hassan; Clausen, Sébastien; Ribeiro, M. Luisa; Solá, Rita

    2015-04-01

    The Cambrian Tamdroust and Bab n'Ali Volcanic Complexes represent two magmatic episodes developed in the latest Ediacaran-Cambrian Atlas Rift of Morocco. Their rifting pulses were accompanied by accumulation of volcanosedimentary edifices (dominated by effusive lava flows in the former and explosive acidic aprons in the latter) associated with active tilting and uplift. Sealing of their peneplaned horst-and-graben palaeotopographies led to the onset of distinct onlapping geometries and angular discordances capping eroded basements ranging from the Ediacaran Ouarzazate Supergroup to the Cambrian Asrir Formation. Previous interpretations of these discordances as pull-apart or compressive events are revised here and reinterpreted in an extensional (rifting) context associated with active volcanism. The record of erosive unconformities, stratigraphic gaps, condensed beds and onlapping patterns across the traditional "lower-middle Cambrian" (or Cambrian Series 2-3) transition of the Atlas Rift must be taken into consideration for global chronostratigraphic correlation based on their trilobite content.

  15. Scattered radiation doses during cardiac studies using a U-arm type fluoroscopy system

    International Nuclear Information System (INIS)

    The advent of image intensifier systems incorporating a U-arm with parallelogram support, a greater awareness of scattered radiation levels is needed, in particular to cardiologists. Depending on the projection, the cardiologist can now be subjected to scatter from the primary side of the patient, giving rise to much higher levels of scattered radiation. Doses to cardiologists were measured for typical cardiac studies on such an image intensifier system. Doses to the eyes and thyroid were below the limits recommended by the ICRP, but if the principle of ALARA is to be adhered to consideration needs to be given to a secondary barrier, in addition to the lead apron, to provide protection to the eyes and thyroid of the cardiologist

  16. Scattered radiation dose to radiologist's cornea, thyroid and gonads while performing some x-ray fluoroscopic investigations

    International Nuclear Information System (INIS)

    The mankind has been immensely benefited from discovery of X-ray and it has found wide spread application in diagnosis and treatment. Radiation is harmful and can produce somatic and genetic effects in the exposed person. International Commission on Radiation Protection (ICRP) has recommended a system of dose limitation based on principle of ALARA. All the efforts should be made to keep the radiation dose to the radiation worker as low as possible. Fluoroscopy gives maximum dose to the patient and staff and hence we have attempted to quantify the scattered radiation dose to the cornea, thyroid and gonads of the radiologist performing fluoroscopic examinations such as barium meal, barium swallow, barium enema, myelography, histerosalpingography and fracture reduction. Thermoluminescence dosimetry (TLD) method using CaSO4:Dy TLD disc was employed for these measurements. Use of lead apron has reduced the dose to radiologist's gonad. (author). 3 refs., 4 tabs

  17. Effects of Priming in Combination with Fungicides on Germination and Infestation of Lettuce (Lactuca sativa L.)

    Institute of Scientific and Technical Information of China (English)

    HU Jin; Tylkowska K

    2005-01-01

    Two seed lots of lettuce (Lactuca sativa L.) cv. Krolowa Majowych were primed in polyethylene glycol (PEG) 8000 at -1.25MPa for 7 days in dark at 20℃. Two fungicide treatments combined with PEG were used to control fungi: 1) Funaben T (0.1%) and Apron 35 SD (0.02%) were added to -1.25 MPa PEG solution (PEG+F); 2) After seed priming and drying,Funaben T was mixed at 5 g kg-1 and Apron 35 SD at 1 g kg-1 of seeds (PEG then F dust). PEG, PEG+F and PEG then F dust treatments reduced significantly thermodormancy and increased the seed germination at 35℃ in both lots. PEG then F dust treatment had the best effect on reducing seed thermodormancy at 35℃, and increased seed germination to 64.5% in lot 1 and 72.0% in lot 2 compared to 0 in untreated. PEG and PEG then F dust treatments have accelerated germination speed at 20 and 15℃ in both lots. There was a significant reduction in seed infestation in which the seeds were treated with PEG+F and PEG then F dust compared to untreated seeds and PEG primed seeds. PEG priming enhanced seed infestation considerably by Alternaria alternata, Penicillium spp., Rhizopus spp. and Ulocladium spp. Mycological analysis showed higher frequency of Alternaria alternata and Ulocladium spp. in untreated seeds at 20℃. Priming in combination with fungicides significantly alleviated the infestation of fungi, especially Alternaria alternata infestation.

  18. Step back from the patient: Reduction of radiation dose to the operator by the systematic use of an automatic power injector for contrast media in an interventional angiography suite

    International Nuclear Information System (INIS)

    Background: During arterial interventional procedures, power injectors allow the operator to step back from the patient or exit the angiography suite during digital subtraction angiography (DSA) acquisitions. Increasing the distance to the radiation source reduces exposure to the operator and staff. Purpose: To systematically investigate the effect of increasing the distance between the radiation source and the operator during DSA acquisitions in a daily clinical setting, regarding radiation exposure to the operator and patient, as well as the duration of the procedure using a power injector to deliver contrast media. Material and Methods: Patients scheduled for arterial interventional procedures in the pelvis or lower extremities were consecutively included. In phase one (duration 6 weeks, 44 patients) contrast media were injected manually. In phase two (duration until the total dose area product [DAP] was equal to phase 1, 41 patients) the operator used a power injector and exited the suite whenever possible. Patient, procedure, and examination data were recorded. Collective dose to the operator's collar, lead apron, and hands was recorded using thermo luminescent dosimetry (TLD). Results: Our results showed a dose reduction of 50% to the operator's hands, lead apron, and thyroid collar when using a power injector during DSA, with no significant increase in DAP or procedure time when performing pelvic procedures. For lower extremity procedures there was a small but significant increase in procedure time and DAP. Pelvic procedures yielded substantially higher DAP than lower extremity procedures during both phases. Conclusion: Utilization of a power injector, thus allowing the operator to step back from the patient, facilitates a radiation dose reduction to the operator of approximately 50% with no significant increase in patient dose or procedure time during pelvic procedures

  19. Eye lens dose in interventional cardiology.

    Science.gov (United States)

    Principi, S; Delgado Soler, C; Ginjaume, M; Beltran Vilagrasa, M; Rovira Escutia, J J; Duch, M A

    2015-07-01

    The ICRP has recently recommended reducing the occupational exposure dose limit for the lens of the eye to 20 mSv y(-1), averaged over a period of 5 y, with no year exceeding 50 mSv, instead of the current 150 mSv y(-1). This reduction will have important implications for interventional cardiology and radiology (IC/IR) personnel. In this work, lens dose received by a staff working in IC is studied in order to determine whether eye lens dose monitoring or/and additional radiological protection measures are required. Eye lens dose exposure was monitored in 10 physicians and 6 nurses. The major IC procedures performed were coronary angiography and percutaneous transluminal coronary angioplasty. The personnel were provided with two thermoluminescent dosemeters (TLDs): one calibrated in terms of Hp(3) located close to the left ear of the operator and a whole-body dosemeter calibrated in terms of Hp(10) and Hp(0.07) positioned on the lead apron. The estimated annual eye lens dose for physicians ranged between 8 and 60 mSv, for a workload of 200 procedures y(-1). Lower doses were collected for nurses, with estimated annual Hp(3) between 2 and 4 mSv y(-1). It was observed that for nurses the Hp(0.07) measurement on the lead apron is a good estimate of eye lens dose. This is not the case for physicians, where the influence of both the position and use of protective devices such as the ceiling shield is very important and produces large differences among doses both at the eyes and on the thorax. For physicians, a good correlation between Hp(3) and dose area product is shown. PMID:25809107

  20. Occupational dose measurement in interventional cardiology, dosimetry comparison study

    International Nuclear Information System (INIS)

    The number of cardiology interventional procedures has significantly increased recently. This is due to the reliability of the diagnostic equipment to diagnose many heart disease. In the procedures the x-ray used results in increasing radiation doses to the staff. The cardiologists and other staff members in interventional cardiology are usually working close to the area under examination and receive the dose primarily from scattered radiation from the patient. Therefore workers in interventional cardiology are expected to receive high doses. This study overviews the status of occupational exposure at the three cardiology centers at three different hospitals in Khartoum compared with that received by workers at other medical practices (radiotherapy, nuclear medicine and diagnostic radiology) in the Institute of Nuclear and Technology (INMO) at El Gezira. The TLD Harshaw 6600 reader was used in the assessment of effective dose for Hp (10). Two TLDs were used by each worker at the three cardiology centres, one worn under a protective apron and the other worn outside and above the apron as specified by the ICRP. Each worker at the other sections was facilitated with one dosimeter to be worn on the chest. The annual doses received by 14 cardiologists, 13 nurses and 9 technologists at the three cardiology centres were in the range: (0.84-4.77), (0.15-2.08), (0.32-1.10) mSv respectively. In the INMO the annual doses received by 7 doctors, 5 nurses and 14 technologists were in the range: (0.12-0.51), (0.11-0.65), (0.03-1.39) mSv respectively. The results showed that the annual doses received by the workers do not exceed 20 mSv. The study also indicated that doses received by workers in interventional cardiology, in particular the cardiologists are high compared to that received at the other medical sections.(Author)

  1. Online software for the estimation of fetal radiation dose to patients and staff members in diagnostic radiology;Sistema online para o calculo de doses fetais de pacientes e trabalhadoras ocupacionalmente expostas em radiologia diagnostica

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Paulo Roberto; Groff, Sybele Guedes de Paulo, E-mail: pcosta@if.usp.b [Universidade de Sao Paulo (DFN/IFUSP), SP (Brazil). Inst. de Fisica. Dept. de Fisica Nuclear

    2009-07-01

    An online software, named 'Dose Fetal Web', which calculates the dose of the fetus and the radiological risks from both medical and occupational exposures of pregnant women is described. The software uses a mathematical methodology where coefficients for converting uterus to fetal dose, NUD, have been calculated by using Monte Carlo simulation. In the fetal dose from diagnostic medical examination of the pregnant patient, database information regarding output and other equipment related to parameters from the QA database, maternal and fetal parameters collected by ultrasound procedures were used for the fetal dose estimation. In the case of fetal dose of the pregnant staff member the database information regarding routine individual monitoring dosimetry, such as occupational dose and workload, were used for the estimation. In the first case suppose a 26 weeks pregnant patient had to undergo a single AP abdomen procedure (70 kVp peak tube voltage and total filtration 3mmAl), the fetal dose calculated by the software was 4.61 mGy and the radiological risks would be 5.0{center_dot}10{sup -4} and 0.14 to the probability of mental retardation induction and decline in the IQ score, respectively. In the second case, considering that the staff member can be pregnant, and assuming that she wore a 0,5 mm lead equivalent apron during every interventional radiology procedure and a personal dosimetry reading of 2 mGy{sub TLD}/month measured with the TLDs outside the apron, the fetal dose calculated by the software was 0.02 mSv/month. (author)

  2. Step back from the patient: Reduction of radiation dose to the operator by the systematic use of an automatic power injector for contrast media in an interventional angiography suite

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Anne Sofie F. (Oestfold Hospital Trust, Dept. of Radiology, Oslo Univ. Hospital, Oslo (Norway)), Email: annesof@online.no; Oesteraas, Bjoern Helge (The Intervention Centre, Oslo Univ. Hospital, Oslo (Norway); Faculty Div. of Clinical Medicine, Univ. of Oslo, Oslo (Norway))

    2012-04-15

    Background: During arterial interventional procedures, power injectors allow the operator to step back from the patient or exit the angiography suite during digital subtraction angiography (DSA) acquisitions. Increasing the distance to the radiation source reduces exposure to the operator and staff. Purpose: To systematically investigate the effect of increasing the distance between the radiation source and the operator during DSA acquisitions in a daily clinical setting, regarding radiation exposure to the operator and patient, as well as the duration of the procedure using a power injector to deliver contrast media. Material and Methods: Patients scheduled for arterial interventional procedures in the pelvis or lower extremities were consecutively included. In phase one (duration 6 weeks, 44 patients) contrast media were injected manually. In phase two (duration until the total dose area product [DAP] was equal to phase 1, 41 patients) the operator used a power injector and exited the suite whenever possible. Patient, procedure, and examination data were recorded. Collective dose to the operator's collar, lead apron, and hands was recorded using thermo luminescent dosimetry (TLD). Results: Our results showed a dose reduction of 50% to the operator's hands, lead apron, and thyroid collar when using a power injector during DSA, with no significant increase in DAP or procedure time when performing pelvic procedures. For lower extremity procedures there was a small but significant increase in procedure time and DAP. Pelvic procedures yielded substantially higher DAP than lower extremity procedures during both phases. Conclusion: Utilization of a power injector, thus allowing the operator to step back from the patient, facilitates a radiation dose reduction to the operator of approximately 50% with no significant increase in patient dose or procedure time during pelvic procedures

  3. Evidence for false-positive results for boldenone testing of veal urine due to faecal cross-contamination during sampling.

    Science.gov (United States)

    Sgoifo Rossi, C A; Arioli, F; Bassini, A; Chiesa, L M; Dell'Orto, V; Montana, M; Pompa, G

    2004-08-01

    European Directive 96/22/EC, which controls veterinary residues in animals, does not permit the presence of synthetic growth promoters in products of animal origin or in livestock. Boldenone is categorized in class A3 (growth promoters -- steroids) and is thus a banned substance. Testing of veal urine for banned substances is part of the European Union statutory programme for animals going into the food chain. In relation to this monitoring, three studies were conducted to investigate the apparent presence of the banned growth promoter boldenone in veal urine, which was suspected as being caused by interference from faecal contamination of the sample. In the first study, urine samples were collected at different times (time 0 and after 30 min) using (1) a conventional zoonotechnical apron and (2) a technique designed specifically to avoid faecal contamination ('kettle'). This resulted in samples that were, respectively, positive and negative for the presence of alpha-boldenone (alpha-BOL). In a second study, urine samples negative to alpha-BOL were collected from eight veal calves, but became positive after deliberate faecal contamination. In a third study, data obtained from the Italian RNP (Residual National Program) indicated that 18.1% of 3295 urine samples collected using the zootechnical apron were positive for alpha-BOL and 2.1% for beta-boldenone (beta-BOL), whilst of 902 samples collected using the kettle, beta-BOL was not detected in any samples and only 0.2% were positive to alpha-BOL, in concentrations lower than 2 ng ml(-1). These results further support the supposition that faecal contamination of the urine during sample collection can lead to false-positive results during boldenone analysis. PMID:15370825

  4. Logistics for evaluation of doses received by IOE due to handling 18FDG-radiopharmaceutical during processing (IEN/CNEN) and in radiodiagnostic (clinical)

    International Nuclear Information System (INIS)

    The objective of this study is to propose an improvement in radiological practices involving production, transportation and application of radiopharmaceutical 18F, by tracking the radiation doses received by occupationally exposed individuals (OEI) that develop production practices, transportation and application of some patients in hospitals and clinics in Rio de Janeiro, the radiopharmaceutical 18FDG. In light of the results and observations of how these practices are developed, it's necessary to evaluate and suggest a logistics to minimize the doses received by OEI during these practices, seeking improvements in the actions and procedures for radiological protection. In practice the production of the radiopharmaceutical, the study focuses on the time of withdrawal of 18FDG cell processing, where the technician is exposed to higher dose rates. At this stage, we take to accomplish, yet two other reviews: the first is the placement of electronic dosimeters inside and outside the lead apron, whose objective is to assess the attenuation capacity of the apron. This last procedure refers to the use of a phantom cylindrical containing TLD 700 dosimeter in order to evaluate, using a mathematical model (MCNP), the doses ends (hand) of the technician, the process of removing the radiopharmaceutical of the cell and to compare the dosimetric dose recorded in the ring. Regarding the transport of 18FDG, we take into account the doses recorded in the cabin of the vehicle and the doses recorded in the dosimeter of the carrier. Finally, the doses received by health professionals who handle 18FDG are analyzed, since its withdrawal from the packing until administration to the patient. (author)

  5. A study on reducing radiation dose in dental radiography for children, 1

    International Nuclear Information System (INIS)

    X-ray examination is one of the effective diagnoses in dentistry. And it is difficult to conduct a precise dental examination without X-ray films, especially in pedodontics. However, radiography may be attended with many radiation injury, and we must perform the complete protection of patients when taking X-ray radiography for children, because their tissues are much more sensitive to radiation than those of adult. Children have some radiosensitive immature organs such as the thyroid gland, eyes (crystalline lens), gonad etc., accordingly, it is very important to protect them from exposure of X-rey. It has been suggested that the thyroid gland is the most sensitive to radiation among many organs. We, therefore, establish a protector for children's thyroid gland as soon as possible. In this study, the auther had designed X-ray protecting rubber sheet which had various lead contents, for finding an optimum condition of the protector. Additionally, the sheltering effects were compared among ready-made protectors. 1. It was satisfactory for complete sheltering of direct beam that the rubber sheet contained 0.375 mmPb, 0.5 mmPb, and 0.75 mmPb, at the tubevoltage of 65 kVp, 70 kVp and 80 kVp, respectively. 2. The radiolucency ratio of Hagoromo Apron containing 0.25 mmPb was 0 % at 65 kVp, and that of X-ray Shield containing 0.50 mmPb was 0 % at 65, 70 kVp and 80 kVp too. 3. Among the ready-made aprons, there was one which had less lead content than the indicated value. (author)

  6. Determination of eye lens doses and identification of risk groups among radiation exposed workers. An Austrian pilot study

    International Nuclear Information System (INIS)

    On European level, in 2014 the dose limit for the lens of the eye of radiation exposed workers has been reduced from 150 to 20 mSv per year (2013/59/Euratom). Data about eye lens exposition measured under realistic operational conditions of Austrian radiation exposed workers is sparse and there is no information to verify, if all professional groups identified to be at risk for elevated eye doses will remain below the new annual dose limit. Therefore, financed by the Austrian Workers Compensation Board, AUVA, a pilot study has been initiated to answer this question. Based on published information professional groups of radiation exposed workers and operational tasks with an enhanced risk of elevated eye lens doses have been identified. By dosimetric measurements with volunteers (forehead dose meters and parallel measurements with whole-body TL-dose meters above and under the lead apron) realistic lens doses will be estimated during selected radiation exposed tasks. Comparison of yielded doses will show whether a TLD outside the apron could serve as an alternative to forehead dose meters dedicated to measure eye lens doses. Measurements with leaded protective eyewear based on IEC61331 yield results for lead equivalent in good agreement with manufacturers' information. Results for eye lens doses determined by use of a RANDO head phantom and a standardized phantom simulating a body in a typical exposition situation for interventional radiologists show that wearing of leaded goggles allows for a 90% dose reduction. Under such conditions the eye lens dose is dominated by backscatter and stray radiation from the operator's head and patient body. This has to be considered for the evaluation of protective effectiveness for leaded eye wear.

  7. Determination of eye lens doses and identification of risk groups among radiation exposed workers. An Austrian pilot study; Bestimmung der Augenlinsen-Dosis und Identifizierung von Risikogruppen bei beruflich strahlenexponierten Personen. Eine Pilotstudie in Oesterreich

    Energy Technology Data Exchange (ETDEWEB)

    Stadtmann, H.; Hranitzky, C.; Willer, H. [Seibersdorf Labor GmbH, Seibersdorf (Austria). Radiation Protection Dosimetry; Strebl, F.; Ernst, G. [Seibersdorf Labor GmbH, Seibersdorf (Austria). Radiation Safety and Applications; Aspek, W. [Allgemeine Unfallversicherungsanstalt (AUVA), Wien (Austria). Abt. Unfallverhuetung und Berufskrankheitenbekaempfung (HUB)

    2015-07-01

    On European level, in 2014 the dose limit for the lens of the eye of radiation exposed workers has been reduced from 150 to 20 mSv per year (2013/59/Euratom). Data about eye lens exposition measured under realistic operational conditions of Austrian radiation exposed workers is sparse and there is no information to verify, if all professional groups identified to be at risk for elevated eye doses will remain below the new annual dose limit. Therefore, financed by the Austrian Workers Compensation Board, AUVA, a pilot study has been initiated to answer this question. Based on published information professional groups of radiation exposed workers and operational tasks with an enhanced risk of elevated eye lens doses have been identified. By dosimetric measurements with volunteers (forehead dose meters and parallel measurements with whole-body TL-dose meters above and under the lead apron) realistic lens doses will be estimated during selected radiation exposed tasks. Comparison of yielded doses will show whether a TLD outside the apron could serve as an alternative to forehead dose meters dedicated to measure eye lens doses. Measurements with leaded protective eyewear based on IEC61331 yield results for lead equivalent in good agreement with manufacturers' information. Results for eye lens doses determined by use of a RANDO head phantom and a standardized phantom simulating a body in a typical exposition situation for interventional radiologists show that wearing of leaded goggles allows for a 90% dose reduction. Under such conditions the eye lens dose is dominated by backscatter and stray radiation from the operator's head and patient body. This has to be considered for the evaluation of protective effectiveness for leaded eye wear.

  8. Geologic Mapping of Ascraeus Mons, Mars

    Science.gov (United States)

    Mohr, K. J.; Williams, D. A.

    2015-12-01

    Ascraeus Mons is one of the three large shield volcanoes in the Tharsis Montes province on Mars. We are conducting geologic mapping of Ascraeus in ArcMap 10.3 at 1:1,000,000 scale using a CTX dataset as a primary basemap. The CTX dataset is supplemented by HRSC, HiRISE, THEMIS, and MOLA data. Our objective is to determine the areal extent, distribution, and age relationships of different lava flow morphologies on the main flank, rift apron, and associated small-vent field of Ascraeus Mons to: (1) identify and understand changes in effusive style across the volcano, and (2) provide insight into martian magma production rates. Our mapping, thus far, at a CTX resolution (~6 m/pixel) shows a variety of effusive styles on the flanks, rift aprons, and plains on and around Ascraeus Mons. Our plan to address (1) is to create a geologic map of Ascraeus Mons. We will use this map to determine where and how different lava flows were emplaced on the flanks and surrounding plains of Ascraeus Mons. We will determine relative ages of units using the emplacement of different geological units, impacts, tectonics, and erosion via superposition relations. We will relate eruptive styles by comparing how different flows are oriented around Ascraeus Mons. Our plan for (2) is to use CTX, MOLA and HRSC datasets to determine volumes of the emplaced lava flows. The volumes will be used to calculate yield strengths and viscosities of each flow. The yield strengths and viscosities will be used to calculate magma production rates. These will prove important to better understand the history and creation of Ascraeus Mons and other volcanoes on other planetary bodies.

  9. Online software for the estimation of fetal radiation dose to patients and staff members in diagnostic radiology

    International Nuclear Information System (INIS)

    An online software, named 'Dose Fetal Web', which calculates the dose of the fetus and the radiological risks from both medical and occupational exposures of pregnant women is described. The software uses a mathematical methodology where coefficients for converting uterus to fetal dose, NUD, have been calculated by using Monte Carlo simulation. In the fetal dose from diagnostic medical examination of the pregnant patient, database information regarding output and other equipment related to parameters from the QA database, maternal and fetal parameters collected by ultrasound procedures were used for the fetal dose estimation. In the case of fetal dose of the pregnant staff member the database information regarding routine individual monitoring dosimetry, such as occupational dose and workload, were used for the estimation. In the first case suppose a 26 weeks pregnant patient had to undergo a single AP abdomen procedure (70 kVp peak tube voltage and total filtration 3mmAl), the fetal dose calculated by the software was 4.61 mGy and the radiological risks would be 5.0·10-4 and 0.14 to the probability of mental retardation induction and decline in the IQ score, respectively. In the second case, considering that the staff member can be pregnant, and assuming that she wore a 0,5 mm lead equivalent apron during every interventional radiology procedure and a personal dosimetry reading of 2 mGyTLD/month measured with the TLDs outside the apron, the fetal dose calculated by the software was 0.02 mSv/month. (author)

  10. Eye lens dose in interventional cardiology

    International Nuclear Information System (INIS)

    The ICRP has recently recommended reducing the occupational exposure dose limit for the lens of the eye to 20 mSv y-1 , averaged over a period of 5 y, with no year exceeding 50 mSv, instead of the current 150 mSv y-1 . This reduction will have important implications for interventional cardiology and radiology (IC/IR) personnel. In this work, lens dose received by a staff working in IC is studied in order to determine whether eye lens dose monitoring or/and additional radiological protection measures are required. Eye lens dose exposure was monitored in 10 physicians and 6 nurses. The major IC procedures performed were coronary angiography and percutaneous transluminal coronary angioplasty. The personnel were provided with two thermoluminescent dosemeters (TLDs): one calibrated in terms of Hp(3) located close to the left ear of the operator and a whole-body dosemeter calibrated in terms of Hp(10) and Hp(0.07) positioned on the lead apron. The estimated annual eye lens dose for physicians ranged between 8 and 60 mSv, for a workload of 200 procedures y-1. Lower doses were collected for nurses, with estimated annual Hp(3) between 2 and 4 mSv y-1. It was observed that for nurses the Hp(0.07) measurement on the lead apron is a good estimate of eye lens dose. This is not the case for physicians, where the influence of both the position and use of protective devices such as the ceiling shield is very important and produces large differences among doses both at the eyes and on the thorax. For physicians, a good correlation between Hp(3) and dose area product is shown. (authors)

  11. Periglacial landforms on Mars as evidence of undersurface ice

    Science.gov (United States)

    Sik, A.

    -sized rock glaciers formed from the gravitational talus regions of the inner walls of the caldera. The most typical form is a young and active, lobate-shaped rock glacier bordered by steep side- and front slopes and with well-defined transversal furrows-and-ridges pattern on its surface. The second location is more isolated, in the Pleistocene it was a cirque-region of a normal glacier. Recently there is only one rock glacier in the area, so that is very well bordered. The geomorpological map of this form shows curvilinear pattern, as a result of plastic deformation of inner ice lens. The lower end of this rock glacier has bigger units and deeper troughs between them. Perhaps it is resulted from changing active and less active periods of movement, in connection with temperature oscillations. 5. Debris aprons on Mars From Viking Orbiter images fretted terrains of Mars has known as high-relief transition zones between the young, northern low-lying plains and the old, southern highlands of the planet [4]. Here the isolated highland-mesas are surrounded by plastic, skirt-like forms of rock debris: these are called debris aprons. Their formation is supported by the global cryosphere. Other morphological evidences of this latitude-specific ice-rich layer are the rampart craters, relief relaxation phenomena, poligon-shaped surface matrix, thermokarst-like features and indirectly the formation of outflow channels [5]. These debris aprons can extend to 15-25 km long, they have a convex shape, steep frontal- and side slopes and they are differs from gravitational talus or fluvial aprons, respectively. The source of their rock debris is the intensive physical weathering, and their ice emanates from the underlying layers, from the mesa's material or condense from the atmosphere [6]. Primarily the ice content-related mass movement mechanisms (continuous creep and episodic sliding) are responsible for the plastic appearance of these forms [7]. The detailed analysis of three Martian debris

  12. Modeling of Tsunami Currents in Harbors

    Science.gov (United States)

    Lynett, P. J.

    2010-12-01

    , there must be some limitations for predicting the turbulent flow structures, even if they are dominantly 2D-horizontal motions. In this paper, the turbulent motions due to long waves and currents, with a focus on port and harbor effects, is investigated. Recent work studying wind wave evolution inside harbors and tsunami effects inside and near harbors will be presented. Presented case studies will focus on the generation of turbulent eddies by structures such as breakwaters and wharves, and the controlling effects these eddies have on currents. The knowledge that these types of currents might occur in a harbor is very important for planning, and for emergency operations during such an event. Okal, E.A., Fritz, H.M., Synolakis, C.E., Raad, P.E., Al-Shijbi, Y., and Al-Saifi, M., 2006. Field survey of the 2004 Indian Ocean tsunami in Oman, 2004, Great Sumatra Earthquakes and Indian Ocean Tsunamis of December 26, 2004 and March 28, 2005, Earthquake Spectra 22 (S4), June 2006.

  13. Evidence for Recent Liquid Water on Mars: Basic Features of Martian Gullies

    Science.gov (United States)

    2000-01-01

    Water is the chief agent of weathering and erosion on Earth. Mars is a much drier, colder planet on which liquid water cannot exist very long at the surface because it will immediately begin to boil, evaporate, and freeze--all at the same time. However, new pictures from the Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) have provided an astonishing observation which suggests that liquid water may have played a role in shaping some recent gully-like features found on the slopes of various craters, troughs, and other depressions on the red planet.These pictures introduce the basic features of a martian gully. The figure on the left is an example from Mars, the figure on the right is a gully on Earth. In the Earth picture, rain water flowing under and seeping along the base of a recently-deposited volcanic ash layer has created the gully. For Mars, water is not actually seen but is inferred from the landforms and their similarity to examples on Earth.The landforms both on Earth and Mars are divided into three parts: the alcove, the channel, and the apron. Water seeps from between layers of rock on the wall of a cliff, crater, or other type of depression. The alcove forms above the site of seepage as water comes out of the ground and undermines the material from which it is seeping. The erosion of material at the site of seepage causes rock and debris on the slope above this area to collapse and slide downhill, creating the alcove.The channel forms from water and debris running down the slope from the seepage area. The point where the top of the channel meets the bottom of the alcove is, in many cases, the site where seepage is occurring. Channels are probably flushed-clean of debris from time to time by large flash floods of water released from behind an ice barrier that might form at the site of seepage during more quiescent times.The aprons are the down-slope deposits of ice and debris that were moved down the slope and through the channel

  14. Interpretation of 1.5-m resolution AUV bathymetry using ROV observations and samples at Davidson and Rodriguez Seamounts

    Science.gov (United States)

    Paduan, J. B.; Clague, D. A.; Caress, D. W.; Thomas, H.; Conlin, D.; Thompson, D.

    2010-12-01

    The summits and upper flanks of Rodriguez and Davidson Seamounts off California were mapped at 1.5-m resolution by the MBARI Mapping AUV. The seamounts were built by episodic eruptions on abandoned spreading ridges 10-12 and 10-15 Ma, respectively. They consist of ridges and elongate cones that parallel the old spreading axes, yet have strikingly different summit morphologies. Video observations and samples from prior ROV Tiburon dives are used to interpret the textures revealed in the AUV data, and are extrapolated to make geologic maps of the seamounts. The summit of Davidson is rugged and studded with cones of three general classes: completely smooth cones with nearly circular bases, mounds elongated into subparallel ridges, and disorganized mounds of rounded shapes. The elongated mound ridge-lines are roughly rectangular in cross-section, and smooth apron-like slopes descend below. They and the smooth cones occupy the highest points on the seamount but also occur deeper, whereas the disorganized mounds occur only deeper. Smooth, flat pockets lie between the cones. The disorganized mounds were identified as pillow lavas during ROV dives. The mounds that form ridges are blocky ’a’a-like flows, probably oriented over eruptive fissures. Lava samples vary from basalt to trachyte, and there is no correlation between the presumed fluidity of the lavas and occurrence of pillows. The smooth aprons below the blocky flows, and presumably the smooth cones, are glass-rich, volcaniclastic debris produced by explosive activity above. The debris has bedding parallel to the steep slopes, and has lithified into pavement. Pelagic sediment has accumulated between the cones. An inflated flow drained at its distal end in a valley between two ridges; collapses in the flow have drainback veneers like bath-tub rings on the inner surfaces. The summit of Rodriguez has no cones, but they dot the flanks. They are smooth with nearly circular bases and mounds elongated into ridges with

  15. Determining change of bathymetry with GPR method in Ordu-Giresun, a sea-filled airport in the Black Sea, Turkey

    Science.gov (United States)

    Kadioglu, Selma; Kagan Kadioglu, Yusuf

    2016-04-01

    Ordu-Giresun (OGU) is a newly-constructed airport, the first sea-filled airport in Turkey and in Europe, and the second airport in the world after Osaca-Japan. The airport is between Gulyalı district in Ordu city and Piraziz district in Giresun city in Black Sea -Turkey. A protection breakwater has been constructed by filling a rock approximately 7.435-m long and with an average height of 5.5 m. Then, the Black Sea has been filled until 1 m over the sea level, approximately the area is 1.770.000 m2 wide and includes a runway, aprons and taxiway covered by breakwater. The runway has a 1-m thickness, 3-km length and 45-m width, PCN84 strength, and stone mastic asphalt surface. The aprons has a 240 x 110 m length and PCN110 strength, the taxiway is 250 x 24 m wide. The airport was started to be constructed in July 2011 and it began to serve on 22th May 2015. The aim of this study was to determine the depth of the rock-filled layer and the amount of sinking of the bathymetry which has been determined before filling processing. In addition, before bathymetry determination, unconsolidated sediments had been removed from the bottom of the sea. There were four drilling points to control the sinking of the bathymetry. Therefore, six suitable Ground Penetrating Radar (GPR) profiles were measured, crossing these points with runway and aprons, using 250-MHz and 100-MHz shielded antennas. Starting points of the profiles were in the middle of the runway to merge between depth and thickness changing of the filled layer and bathymetry along the profiles. Surface topography changing was measured spaced 1 m apart with 1 cm sensitivity on each profile. At the same time, similarly the topography changing, bathymetry coordinates was re-arranged along the each profile. Topography corrections were applied to the processed radargrams and then the bottom boundary lines of the rock-filled layer were determined. The maximum height was 3.5 m according to the sea level, which was on the

  16. Estratigrafía, facies y evolución depositacional de la Formación Sauce Grande (Carbonífero Superior: Cuenca Sauce Grande, Sierras Australes, Buenos Aires, Argentina Stratigraphy, facies and depositional evolution of the Sauce Grande Formation (Upper Carboniferous: Sauce Grande Basin, Sierras Australes, Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    R. R. Andreis

    2003-06-01

    waques (Smw representan flujos de detritos finos y densos transicionales a flujos licuefactos. Las demás areniscas representan acción de oleaje o corrientes (Sr o por acreción frontal en barras transversales o dunas de arena por flujos traccionales (Sp. El comienzo de los procesos depositacionales de la Formación Sauce Grande fue caracterizado por una rápida transgresión en el Carbonífero tardío bajo condiciones de moderada subsidencia (procesos eustáticos. El megaciclo inferior se caracteriza por la sedimentación en un slope apron o debris apron localizado en las cercanías del talud continental, con fuerte agradación y rara progradación y depende del régimen termal de la base de los glaciares africanos de base fría, bajo condiciones de sistema de mar bajo. En el megaciclo medio significa una rápida fase de avance glaciar asociada a somerización isostática y el tope del apron habría sido retrabajado por olas y corrientes, creando una plataforma costa afuera casi emergente. En el megaciclo superior se produce un nuevo ascenso del mar (cortejo de mar alto, asociado al retroceso de los glaciares en el sector sudafricano y produce la transgresión tastubiana que se continúa en la Formación Piedra Azul. La disminucion del aporte se hace visible por la sistemática disminución en el espesor de las facies, una mayor frecuencia de facies Dmm1 y Smw y la interacción de depósitos pelíticos, que fueron depositados en plataformas de baja pendiente donde se han registrado avance y retroceso de los glaciares. Dos glaciohorizontes fueron identificados: el GH1 vinculado al megaciclo medio y el GH2 en el contacto entre las Formaciones Sauce Grande y Piedra Azul.The detailed analyses of the lithofacies (including their composition and the depositional processes related to the Sauce Grande Formation, represent the first siliciclastic sedimentation at the Sauce Grande Basin. Two profiles were studied: the North profile (with 826 m and the South profile (with 1095 m

  17. Medical radiation shielding effect by composition of barium compounds

    International Nuclear Information System (INIS)

    Highlight: ► Radiation shielding sheet was manufactured using BaSO4 and a combination of tourmaline, tungsten, silicon and rubber polymer. ► The particle packing of barium tends to be related to the tensile strength. ► The tensile strength was most excellent in the sheets containing rubber. ► The shielding ability of the tungsten and silicon combination with BaSO4 was the same as that of a 0.3 mm lead equivalent. - Abstract: Shielding aprons were manufactured from barium sulfate as a potential substitute for the lead aprons used most commonly for medical radiation shielding. Six types of radiation shielding sheets made from a combination of tungsten, molybdenum, rubber and silicon with a barium sulfate base were manufactured, and their transmission doses were compared with those of a lead standard. In the process of producing the radiation shielding sheets, the particle packing and porosity of the materials, appropriate weight-average molecular weight to number-average molecular weight ratio and tensile strength were investigated to determine the optimal mixing process. The transmission dose was measured by applying a lead equivalent test method () of X-ray protective supplies in the Korea Industrial Standard. The transmission doses of the lead standard with a thickness of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3 and 0.35 mm, as well as the six types of radiation shielding sheet were obtained at a tube voltage of 50, 80, 100, 120 and 150 kVp. According to the results, the combination of barium, tungsten, molybdenum and silicon recorded a dose of a 0.3 mm lead equivalent and its particle packing and porosity were 28–36% and 12–22%, respectively. Nevertheless, satisfactory shielding ability could be obtained with a porosity >20% and particle packing of 30%. Therefore, it is a potential replacement for lead sheet and can be considered a proper medical radiation shielding sheet with good economic feasibility.

  18. Radiation protection in radioimmunotherapy with yttrium-90

    International Nuclear Information System (INIS)

    Full text: Unsealed sources of radioactive isotopes have widely used in the clinical practise. For therapeutic use and with oncological aims, Yttrium-90 has been implemented recently in our hospital. Isotope injection is made by intravenous way slowly at an approximated rate of ten microlitres per second. Low-volume injection, less than ten millilitres, entails the possibility that an important fraction of the prescribed activity could be retained and not incorporated into the patient if a pumping injection system controlled in the distance had been used. To avoid this adversity and in order to get the therapeutic effect, in our hospital the injection is applied directly using a syringe by infirmary personnel of the nuclear medicine department. This circumstance and the radiation emission scheme of Yttrium-90 entails a meticulous radiation safety plan. Measurement of the radiation levels in some different phases of the treatment and at its end, was made by the medical physics department. Also, and before the injection, this department made with the received dose other additional measurements, using ant not using shielding materials, to choose the best option of radiation protection. The use of a syringe protector made of plastic with a thickness between 12 and 17 mm in combination with the use of a leaded apron of 0.25 mm lead thickness worn by the nurse, has been the chosen option. In addition, it was evaluated the most optimized positions for the injection, moving away the nurse from the patient to prevent the risk of radioactive contamination; also the worker was wearing double gloves, glasses and additional protection covering the leaded apron and preventing any kind of accidental contamination. Once the isotope is administrated and bio distributed in the patient's organism, it could be verified that the dose rate around it fell rapidly. The involved personnel were wearing all the time two thermoluminescent dosimeters: for body and for wrist. A maximum of one

  19. Use of personal radiation protection tools and individual dosimetric monitoring in a sample of interventional cardiologists in France, 2005-2009

    International Nuclear Information System (INIS)

    Interventional cardiologists (ICs) are repeatedly exposed to scattered ionising radiation during the cardiac procedures they perform, and radiation protection is an important issue for these medical professionals. The use of radiation protection tools is particularly relevant to this population. SISERI (Systeme d'Information de la Surveillance de l'Exposition aux Rayonnement Ionisants, that is, an information system for monitoring exposure to ionising radiation) is a register that stores personal dosimeter readings for dosimetric monitoring. This paper, based on data for a sample of French ICs from the O'CLOC epidemiological study, aims to provide an overview of the use of radiation protection equipment and dosimetric devices reported by ICs in a specific questionnaire as well as the dosimetric information found in the SISERI database for this population. Material and Methods - Annual information on interventional cardiology activity for the period from 01/01/2005 to 31/12/2009 was collected in an occupational questionnaire. ICs were asked to report the frequency in which they used individual dosimeter and radiation protection tools (lead apron, thyroid shield, eye-wear or face shield, ceiling-suspended shield) as follows: never (0% of the time), occasionally (50%), always (100%). We retrieved their medical radiation exposure information (monitored status and monthly effective doses) from the SISERI database for the period 2005-2009. Results - Information for 132 ICs (mean age in 2005 = 46 ± 7 years) was available. All ICs reported routine use of lead aprons, in contrast to their occasional use of lead eye-wear or face shields. During the study period, 49% reported systematic use of personal dosimeters, and 21% more regular use. On the other hand, 18% never used a dosimeter during this period. The SISTERI database included 92% of our population, 73% of whom had complete annual dose monitoring in SISERI (corresponding to at least 11 months per year of recorded data

  20. Radiation organ doses received in a nationwide cohort of U.S. radiologic technologists: methods and findings.

    Science.gov (United States)

    Simon, Steven L; Preston, Dale L; Linet, Martha S; Miller, Jeremy S; Sigurdson, Alice J; Alexander, Bruce H; Kwon, Deukwoo; Yoder, R Craig; Bhatti, Parveen; Little, Mark P; Rajaraman, Preetha; Melo, Dunstana; Drozdovitch, Vladimir; Weinstock, Robert M; Doody, Michele M

    2014-11-01

    In this article, we describe recent methodological enhancements and findings from the dose reconstruction component of a study of health risks among U.S. radiologic technologists. An earlier version of the dosimetry published in 2006 used physical and statistical models, literature-reported exposure measurements for the years before 1960, and archival personnel monitoring badge data from cohort members through 1984. The data and models previously described were used to estimate annual occupational radiation doses for 90,000 radiological technologists, incorporating information about each individual's employment practices based on a baseline survey conducted in the mid-1980s. The dosimetry methods presented here, while using many of the same methods as before, now estimate 2.23 million annual badge doses (personal dose equivalent) for the years 1916-1997 for 110,374 technologists, but with numerous methodological improvements. Every technologist's annual dose is estimated as a probability density function to reflect uncertainty about the true dose. Multiple realizations of the entire cohort distribution were derived to account for shared uncertainties and possible biases in the input data and assumptions used. Major improvements in the dosimetry methods from the earlier version include: A substantial increase in the number of cohort member annual badge dose measurements; Additional information on individual apron usage obtained from surveys conducted in the mid-1990s and mid-2000s; Refined modeling to develop lognormal annual badge dose probability density functions using censored data regression models; Refinements of cohort-based annual badge probability density functions to reflect individual work patterns and practices reported on questionnaires and to more accurately assess minimum detection limits; and Extensive refinements in organ dose conversion coefficients to account for uncertainties in radiographic machine settings for the radiographic techniques

  1. Spatially limited mud turbidites on the Cascadia margin: segmented earthquake ruptures?

    Directory of Open Access Journals (Sweden)

    C. Goldfinger

    2013-08-01

    Full Text Available A series of 23 thin, mostly mud-silt turbidites are found interspersed between larger, well-dated and regionally correlated paleoseismic sandy turbidites that extend along most of the Cascadia margin, northwestern United States. Investigation of the structure, distribution, and sedimentology of these thin mud-silt units supports the interpretation of these units as turbidites originating on the continental slope. Interpretation of mud turbidites is inhibited by bioturbation and lower response to analytical and imaging techniques; nevertheless most of the 23 interpreted beds exhibit most of the characteristics of coarser turbidites. These characteristics include sharp bases, fining upward sequences, darker color, increased gamma and CT density and magnetic susceptibility relative to the hemipelagic background, sparse microfossils, high lithic content, and evidence of transport from marine sources on the continental slope. New core data from sites south of Rogue Apron indicate that sandy and muddy turbidites may be correlated at least 150 km south to Trinidad Plunge Pool for the period ~ 4800 yr BP to present. Many of the mud turbidites initially described at Rogue Apron coarsen southward, becoming sandy turbidites. High-resolution Chirp seismic profiles reveal that turbidite stratigraphy along the base of the southern Cascadia continental slope is continuous, with little variation for at least 240 km along strike. The Chirp data show that turbidites along the Cascadia base of slope are ubiquitous, and likely not sourced solely from submarine canyon mouths, but may also have been delivered to the proximal abyssal plain as sheet flows from the open continental slope and coalescing local sources. Regional stratigraphy reveals that hemipelagic sedimentation rates and total Holocene turbidite thickness and mass are similar at widely separated sites, yet the total thickness of the Holocene section is greater by a factor of two in southern Cascadia

  2. Radiation exposure to patient and radiologist during transcatheter arterial embolization therapy for hepatocellular carcinoma. Multicenter study in Japan

    International Nuclear Information System (INIS)

    Transcatheter arterial embolization (TAE) is now most commonly used as a treatment of hepatocellular carcinoma. Present multicenter study was carried out to evaluate radiation exposure to patients and interventional radiologists during the procedure. Thirty-nine procedures of TAE for hepatocellular carcinoma in eight institutes were analyzed. Radiation exposure to the patients and the interventional radiologists were evaluated with LiF thermoluminescence dosimeters (TLDs) placed on the patient's skin at the posterior hepatic portion and the pelvis and the operator's forehead and abdomen (in front and back of the lead apron). A real-time dosimeter was also used to evaluate skin dose of the patient. TAE was performed by angiographic techniques, using a microcatheter advanced to the hepatic artery branch(es) under the guidance of X-ray fluoroscopy and digital subtraction angiography (DSA), and then injecting chemotherapeutic agents mixed with oily contrast material and followed by gelatin sponge particles. The mean fluoroscopic time was 21 minutes and the mean number of DSA acquisition was 6. TLD dosimetry showed that the mean entrance surface dose of the patient at the hepatic portion was 973±681 mSv (mean±SD), and the anterior skin dose at the pelvis was 0.98±0.69 mSv. The doses of the radiologist were 0.04±0.04 mSv at the forehead, 0.15±0.19 mSv at the abdomen in front of the lead apron, and 0.005±0.01 mSv behind it. The real-time dosimetry showed that 56% of the surface dose at the hepatic portion was from DSA and 44% was from fluoroscopy. The radiation exposure to the patients and the interventional radiologists during TAE for hepatocellular carcinoma was considered to be acceptable when proper techniques are used. Further effort to reduce radiation doses during the procedure will be directed toward both digital angiographic and fluoroscopic techniques. (author)

  3. Correlations between Archaeal Diversity and Geochemical Parameters in an Arsenic-Rich Hydrothermal System

    Science.gov (United States)

    Franks, M.; Omelon, C.; Engel, A. S.; Bennett, P.

    2009-04-01

    Characterizing microbial communities within their geochemical environment is useful for understanding microbial distribution and microbial adaptations to extreme physical and chemical conditions. The hydrothermal waters at El Tatio geyser field (ETGF) demonstrate extreme geochemical conditions, with discharge water from springs and geysers at local boiling temperature (85oC), arsenic concentrations of 0.5 mM, and inorganic carbon concentrations (DIC) as low as 0.2mM. Yet many of El Tatio's hundred plus hydrothermal features host extensive microbial mat communities. Recent work has shown correlations between the metabolic guilds of microorganisms present and variations in water chemistry. ETGF is a high-altitude hydrothermal basin with over 100 mapped hydrothermal features, located within a 30km2 area near the Chile-Bolivia border. The Na-Cl type waters have a circumneutral pH and contain abundant dissolved metals. Shallow runoff aprons extend tens of meters from some geyser features, where silica rapidly precipitates from cooling water. Thick mats, which appear microbial but consist primarily of silica, iron and arsenic mineral deposits, containing

  4. Radiation exposure to the surgeon during closed interlocking intramedullary nailing

    Energy Technology Data Exchange (ETDEWEB)

    Levin, P.E.; Schoen, R.W. Jr.; Browner, B.D.

    1987-06-01

    During interlocking intramedullary nailing of twenty-five femoral and five tibial fractures, the primary surgeon wore both a universal film badge on the collar of the lead apron and a thermoluminescent dosimeter ring on the dominant hand to quantify the radiation that he or she received. When distal interlocking was performed, the first ring was removed and a second ring was used so that a separate recording could be made for this portion of the procedure. At the conclusion of the study, all of the recorded doses of radiation were averaged. The average amount of radiation to the head and neck during the entire procedure was 7.0 millirems of deep exposure and 8.0 millirems of shallow exposure. The average dose of radiation to the dominant hand during insertion of the intramedullary nail and the proximal interlocking screw was 13.0 millirems, while the average amount during insertion of the distal interlocking nail was 12.0 millirems. Both of these averages are well within the government guidelines for allowable exposure to radiation during one-quarter (three months) of a year. Precautions that are to be observed during this procedure are recommended.

  5. Origins of Sinuous and Braided Channels on Ascraeus Mons, Mars - A Keck Geology Consortium Undergraduate Research Project

    Science.gov (United States)

    de Wet, A. P.; Bleacher, J. E.; Garry, W. B.

    2012-01-01

    Water has clearly played an important part in the geological evolution of Mars. There are many features on Mars that were almost certainly formed by fluvial processes -- for example, the channels Kasei Valles and Ares Vallis in the Chryse Planitia area of Mars are almost certainly fluvial features. On the other hand, there are many channel features that are much more difficult to interpret -- and have been variously attributed to volcanic and fluvial processes. Clearly unraveling the details of the role of water on Mars is extremely important, especially in the context of the search of extinct or extant life. In this project we built on our recent work in determining the origin of one channel on the southwest rift apron of Ascraeus Mons. This project, funded by the Keck Geology Consortium and involving 4 undergraduate geology majors took advantage of the recently available datasets to map and analyze similar features on Ascraeus Mons and some other areas of Mars. A clearer understanding of how these particular channel features formed might lead to the development of better criteria to distinguish how other Martian channel features formed. Ultimately this might provide us with a better understanding of the role of volcanic and fluvial processes in the geological evolution of Mars.

  6. Dynamic and Fatigue Analysis of an 18th Century Steel Arch Bridge

    International Nuclear Information System (INIS)

    Within the 'Oran-Tlemcen' railway line realization project (159 km), several bridges were built by the Railroads Algerian West Company. 7 km from the east of Tlemcen city, this railway line must cross a very broken mountainous collar, that's why the French engineer 'Gustave Eiffel' was solicited to construct a 68 m length bridge. In 1890, an arch steel truss bridge was realized. The bridge presents 300 m of apron curvature radius and, currently, is considered as one of the most important monuments of the Algerian historical heritage. Considering the age of the bridge and the evolution of the railway loads in time, it was essential to check the good behavior of the studied structure. For that, analyses to verify the physical and mechanical properties of the growth iron members are made. A finite element model of the bridge was built and numerical simulations were drawn. The structural vibration conducted analysis permit to understand the behavior of this particular structure, then to evaluate (in detail) the rate of the structure fatigue

  7. Chlorine-36 Exposure Dating of Recent Explosive Events on Mauna Loa, Hawaii

    Science.gov (United States)

    Hungerford, J. D.; Stone, J. O.; Fifield, K.; Trusdell, F. A.

    2002-12-01

    We have dated lavas and explosive debris from around the summit caldera of Mauna Loa using in-situ produced cosmogenic Cl-36. Explosive deposits occur as three debris aprons of blocks up to 2 meters. Within the ejecta debris are intrusive rocks (gabbros, pyroxenites), and vesicular and dense basalts. The pahoehoe substrate of the northwest fan has an apparent exposure age of 970 +/- 120 years, in good agreement with radiocarbon ages that range in age from 1090 - 1200 yr B.P. Three clasts from the NW fan have exposure ages ranging from 930+/-120 to 1140+/-120 years, indicating an explosive eruption occured very shortly after emplacment of the underlying flow. These ages should be regarded as upper limits until we have confirmed that Cl-36/Cl ratios are low in freshly erupted Mauna Loa basalt. Low initial ratios (<1e-15) are anticipated based on magmatic U, Th and Cl concentrations and likely magma chamber residence times. Low ratios would also result from assimilation of marine chloride with Cl-36/Cl <1e-15. However, assimilation of surficial material, or magmatic interaction with Cl-36 bearing groundwater might result in higher initial values. We are measuring samples from the 1975 and 1984 eruptions to investigate these possibilities.

  8. A correlation study of eye lens dose and personal dose equivalent for interventional cardiologists.

    Science.gov (United States)

    Farah, J; Struelens, L; Dabin, J; Koukorava, C; Donadille, L; Jacob, S; Schnelzer, M; Auvinen, A; Vanhavere, F; Clairand, I

    2013-12-01

    This paper presents the dosimetry part of the European ELDO project, funded by the DoReMi Network of Excellence, in which a method was developed to estimate cumulative eye lens doses for past practices based on personal dose equivalent values, H(p)(10), measured above the lead apron at several positions at the collar, chest and waist levels. Measurement campaigns on anthropomorphic phantoms were carried out in typical interventional settings considering different tube projections and configurations, beam energies and filtration, operator positions and access routes and using both mono-tube and biplane X-ray systems. Measurements showed that eye lens dose correlates best with H(p)(10) measured on the left side of the phantom at the level of the collar, although this correlation implicates high spreads (41 %). Nonetheless, for retrospective dose assessment, H(p)(10) records are often the only option for eye dose estimates and the typically used chest left whole-body dose measurement remains useful. PMID:23858492

  9. Bell Regio, Venus: Integration of remote sensing data and terrestrial analogs for geologic analysis

    Science.gov (United States)

    Campbell, Bruce A.; Rogers, Patricia G.

    1994-01-01

    The geology and surface morphology of Bell Regio (18-42 deg N, 32-58 deg E) are investigated using a combination of Magellan, Venera, and analogous terrestrial data. The properties of surface units are compared to either direct terrestrial analog measurements or to the behaviors predicted by theoretical models. Five major volcanic sources are identified from geologic mapping (Tepev Mons, Nefertiti corona, a large shield volcano east of Tepev, and two small edifices southeast of Tepev). The volcano Api Mons lies northeast of the main Bell uplift. The oldest volcanic units are associated with an extensive low shield volcano east of Tepev Mons and a small edifice southeast of Tepev. The annular flow apron of Tepev Mons formed next, with volcanism at a second small edifice on the southeast flank of Tepev Mons producing the youngest flow units. Comparisons between Magellan data, terrestrial radar images, and field topography profiles suggest that only three units resemble terrestrial a'a flows; the remainder are consistent with smoother pahoehoe-type surfaces. This suggests that most of the flow units were erupted at relatively low volume effusion rates (less than 100 cu m/sec) over long periods of time or had very low viscosities

  10. Tectonic controls on the geomorphic evolution of alluvial fans in the Piedmont Zone of Ganga Plain, Uttarakhand, India

    Science.gov (United States)

    Goswami, Pradeep K.; Pant, Charu C.; Pandey, Shefali

    2009-06-01

    The Piedmont Zone is the least studied part of the Ganga Plain. The northern limit of the Piedmont Zone is defined by the Himalayan Frontal Thrust (HFT) along which the Himalaya is being thrust over the alluvium of the Ganga Plain. Interpretation of satellite imagery, Digital Terrain Models (DTMs) and field data has helped in the identification and mapping of various morphotectonic features in the densely forested and cultivated Piedmont Zone in the Kumaun region of the Uttarakhand state of India. The Piedmont Zone has formed as a result of coalescing alluvial fans, alluvial aprons and talus deposits. The fans have differential morphologies and aggradation processes within a common climatic zone and similar litho-tectonic setting of the catchment area. Morphotectonic analysis reveals that the fan morphologies and aggradation processes in the area are mainly controlled by the ongoing tectonic activities. Such activities along the HFT and transverse faults have controlled the accommodation space by causing differential subsidence of the basin, and aggradation processes by causing channel migration, channel incision and shifting of depocentres. The active tectonic movements have further modified the landscape of the area in the form of tilted alluvial fan, gravel ridges, terraces and uplifted gravels.

  11. Quality assurance survey of x-ray installations in southern Rajasthan

    International Nuclear Information System (INIS)

    Amongst the man made ionising radiations, x-ray diagnostic procedures contribute the highest per capita radiation dose to population over and above the natural background radiation. Although the x - ray diagnostic procedures have revolutionised the medical diagnosis and treatment of many diseases, it is many a times being over-used as a routine diagnostic procedure like blood or urine test. The patient receives radiation dose in excess due to bad practice and bad equipment, and hence every x - ray machine should be subjected to periodic quality assurance (QA) test. Extensive radiation protection surveys and QA tests of 190 x-ray installations in southern Rajasthan was carried out. It was observed that the kVp calibration was within limit in only 43.6 % of the surveyed units. Similarly the mA linearity was within the prescribed limit in 22.9 % of the units. Out of 190 x - ray machines, 97 (51 %) were more than 10 years old and were never subjected to QA tests after installation. The detailed results of beam alignment test, congruency of optical and radiation field, kV0 linearity, timer linearity and availability of radiation protection equipment such as lead barrier and lead apron discussed. (author)

  12. How Well Does the Present Surface Inventory of Water on Mars Constrain the Past?

    Science.gov (United States)

    Clifford, S. M.; McCubbin, F. M.

    2016-01-01

    Over the past 40 years, estimates of the total outgassed inventory of water on Mars have ranged from a global equivalent layer (GEL) approximately 7-1000 m deep. However, Carr and Head have recently argued that it is not the total inventory of outgassed water that is important, but the amount that exists in climatically exchangeable surface and near surface reservoirs - suggesting that any exchange with water in the deep subsurface is precluded by the existence of a thick cryosphere, at least during the Amazonian and Hesperian. Based on this assumption and their estimate of the present day near-surface inventory of H2O (approximately 34 m GEL, stored as ice in the polar layered deposits (PLD), lobate debris aprons, ice-rich latitude dependent mantles, and as shallow ground ice), they extrapolate the evolution of this inventory backward in time, taking into account the introduction of new water by volcanism, outflow channel activity, and the loss of water by exospheric escape. They conclude that, at the end of the Noachian, Mars had a near-surface water inventory of approximately 24 m and approximately 62 m by the end of the Hesperian - inventories that Carr and Head argue were incompatible with the existence of a former ocean.

  13. An outer ramp to basin plain transect: Interacting pelagic and calciturbidite deposition in the Eocene-Oligocene of the Tuscan Domain, Adria Microplate (Italy)

    Science.gov (United States)

    Ielpi, Alessandro; Cornamusini, Gianluca

    2013-08-01

    The interaction of ramps, basin plains and turbidite systems on the scale of tens of km has been rarely observed in fossil examples. Deep marine Eocene-Oligocene beds are exposed in the axial zone of the Chianti Mountains, Italy, and compose a regionally continue stratigraphic succession known as the Scaglia Toscana Formation. The formation was deposited in the Tuscan Domain of the Adria Microplate. This research aims at depicting its depositional architecture and evolution in the type area. Stratigraphic and sedimentologic analyses were performed on a ca. 25 km-long transect that includes depositional systems sectioned both in the down- and along-dip directions. Shaly-carbonate deposits compose a complex of interacting ramps, basin plains and turbidite floor fan systems. Ramp deposits accumulated above the lysocline and in oxic conditions. Basin plain beds were deposited below the lysocline and were subject to episodes of oxygen depletion. Turbidity flows fed elongate fan lobes characterized by poor channelisation. The basin palaeogeography hampered the development of slope apron turbidite systems. The Eocene-Oligocene geodynamic setting of the Tuscan Domain was characterized by the evolution of a peripheral bulge and by the early structuring of a foredeep basin. Syn-sedimentary tectonism acted a primary role in the basin-scale arrangement. However other mechanisms also contributed to the local facies distribution, including the disposition of sediment-source areas and intrabasinal confinement morphologies, as well as relative oscillations of the depositional surface with respect to the lysocline and oxycline.

  14. Statistical survey of ten criteria established by Portaria 453 of Brazilian Ministry of Health for dentists who use X-rays

    International Nuclear Information System (INIS)

    In July 1998, the Ministry of Health (MS) published the Guidelines for Radiological Protection in Medical and Dental Radiodiagnosis that became known as Portaria 453 - Ordinance 453. This study is designed to evaluate the dentists of Rio de Janeiro on the knowledge and application of the criteria laid down by Ordinance. For this, it was sent to dentists, a form with 13 questions. The issues are related to the use of personal protective clothing (VPI), working procedures for the exam and processing of the image, radioprotection training and quality control. Of 1528 dentists, only 40% have a copy of the Ordinance. Regarding the use of VPI, 94% has lead apron and 76% thyroid shield. Only 63% of dentists observe patients during exposure to X-rays. In 96% of doctor's rooms the revelation of the film is made in a portable box, 71% of these use the visual method to stop processing. The results show the need for greater dissemination of the Ordinance by the odontologist's associations; for an educational work on the topics discussed and training that allow the dentists be prepared to apply the correct work procedures in the production of diagnostic imaging with X-rays

  15. Heathrow Terminal 5 Excavation Archive (Data Paper

    Directory of Open Access Journals (Sweden)

    Framework Archaeology

    2014-06-01

    Full Text Available Framework Archaeology is a Joint Venture agreement between Oxford Archaeology (OA and Wessex Archaeology (WA to provide archaeological services to BAA (formerly British Airports Authority, now Heathrow Airport Holdings Ltd. Given the potential scale of some of BAA's projects, the joint venture enables Framework Archaeology to draw on the full resources of both OA and WA, including site staff, specialist managers, administrative support, and technical facilities. In 1993, BAA plc and Heathrow Airport Limited submitted a joint planning application to develop an additional passenger terminal complex (Terminal 5, together with the provision of aircraft aprons and taxiways, and include the realignment of rivers and landscaping. The resulting archaeological excavations were undertaken as three main phases of work. Excavations in 1996 by the Museum of London Archaeology Service of approximately 4 ha of sludge stockpile areas (site code POK96. Between 1999-2000 Framework Archaeology excavated approximately 21 ha in the Perry Oaks sludge works and adjacent areas (WPR98. Framework Archaeology also undertook excavations between 2002-2007 as part of the construction of Terminal 5 (PSH02, TEC05 covering a further 50 hectares. Importantly the aim of the Terminal 5 archaeological programme was to move beyond the description and recovery of archaeological remains and to arrive at an understanding of the history of human inhabitation and the practical ways in which people established their presence in the material, social and political conditions of their day.

  16. Attitude of the Korean dentists towards radiation safety and selection criteria

    International Nuclear Information System (INIS)

    X-ray exposure should be clinically justified and each exposure should be expected to give patients benefits. Since dental radiographic examination is one of the most frequent radiological procedures, radiation hazard becomes an important public health concern. The purpose of this study was to investigate the attitude of Korean dentists about radiation safety and use of criteria for selecting the frequency and type of radiographic examinations. The study included 267 Korean dentists. Five questions related to radiation safety were asked of each of them. These questions were about factors associated with radiation protection of patients and operators including the use of radiographic selection criteria for intraoral radiographic procedures. The frequency of prescription of routine radiographic examination (an example is a panoramic radiograph for screening process for occult disease) was 34.1%, while that of selective radiography was 64.0%. Dentists' discussion of radiation risk and benefit with patients was infrequent. More than half of the operators held the image receptor by themselves during intraoral radiographic examinations. Lead apron/thyroid collars for patient protection were used by fewer than 22% of dental offices. Rectangular collimation was utilized by fewer than 15% of dental offices. The majority of Korean dentists in the study did not practice radiation protection procedures which would be required to minimize exposure to unnecessary radiation for patients and dental professionals. Mandatory continuing professional education in radiation safety and development of Korean radiographic selection criteria is recommended.

  17. Passive and Active Protective Clothing against High-Power Laser Radiation

    Science.gov (United States)

    Hennigs, C.; Hustedt, M.; Kaierle, S.; Wenzel, D.; Markstein, S.; Hutter, A.

    The main objective of the work described in this paper was the development of passive and active protective clothing for the protection of the human skin against accidental laser irradiation and of active protective curtains. Here, the passive systems consist of functional multi-layer textiles, providing a high level of passive laser resistance. In addition, the active functional multi-layer textiles incorporate sensors that detect laser exposure and are, by means of a safety control, able to deactivate the laser beam automatically.Due to the lack of regulations for testing and qualifying textiles to be used as laser PPE, test methods were defined and validated. Additionally, corresponding testing set-ups were developed.Finally, the gap with respect to standardization was bridged by the definition of a test procedure and the requirements with respect to laser PPE.The developments were demonstrated by a set of tailored functional passive and active laser-protective clothing prototypes (gloves, jackets, aprons, trousers) and active curtains as well as by a prototype testing rig, providing the possibility to perform the specified low-power and high-power textile test procedure.

  18. Dual guidance (CT and fluoroscopy) vertebroplasty: radiation dose to radiologists. How much and where?

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Lesbats, Virginie; Marcy, Pierre-Yves; Amoretti, Marie-eve; Maratos, Yvonne; Ianessi, Antoine; Boileau, Pascal [Centre hospitalier universitaire, Radiology Department, Nice (France); Hauger, Olivier [CHU de Bordeaux, Unite d' Imagerie Osteo-articulaire, Hopital Pellegrin, Bordeaux (France)

    2010-12-15

    The goal of this study was to evaluate the radiation received by the practitioner when performing percutaneous vertebroplasty guided by CT and fluoroscopy for specific anatomical sites: orbits, hands, ankles, and thorax (under lead-lined apron). Twenty-four vertebroplasties were performed on 18 patients. The anatomical site that was most exposed to radiation was the right hand (0.37 mSv on average). This study demonstrates a significant correlation between the irradiation dose and fluoroscopy duration, reflecting both the quantity of primary-beam radiation and backscattered radiation. The right hand (P = 0.03), left hand (P = 0.02), and the left orbit (P < 0.0001) are the anatomical zones that are the most affected by the combination of these two types of radiation, with cumulative irradiation doses of 0.45, 0.2, and 0.14 mSv, respectively. There was a significant correlation between the patient weight and radiation of the left hand (P = 0.03), the left orbit (P = 0.03), and the thorax (P = 0.02), confirming the major influence of backscattered radiation. The most irradiated anatomical sites limiting the number of interventions are the left orbit and the right hand. (orig.)

  19. Fundamental study of a real-time occupational dosimetry system for interventional radiology staff

    International Nuclear Information System (INIS)

    Real-time monitoring of the radiation doses received by interventional radiology (IR) staff has become highly desirable. However, occupational doses are rarely measured in real time, due to the lack of a feasible method for use in IR. Recently, the i2 system by RaySafe™ has been introduced to measure occupational exposure in IR in real time. The i2 system consists of several personal dosimeters (PDs) and a base station with a display and computer interfacing. We evaluated the fundamental performance (dose linearity, dose-rate dependence, angular dependence, batch uniformity and reproducibility) of the i2 system. The dose linearity of the i2 was excellent (R2 = 1.00) The i2 exhibited slight dose-rate dependence (∼20%) at very high dose rates (250 mGy h−1). Little angular dependence (within 20%) was observed between 0° and ±45°, in either the vertical or horizontal direction. We also found that the PD was highly sensitive (about 200%) at angles behind it, e.g. 180°. However, this backscattered radiation is not a problem, in general, due to the placement of the i2 sensor (PD) on the lead apron. We conclude that the i2 system facilitates accurate real-time monitoring and management of occupational doses during IR. (note)

  20. Analysis of occupational doses in interventional radiology and cardiology installations

    International Nuclear Information System (INIS)

    The relationship between patient dose (PD) and occupational dose (OD) is not easily predictable in interventional radiology installations due to a large number of factors which can modify the occupational risk (OR). In the present work an analysis is made of the four main aspects which influence OR, namely, x-ray beam used, radiation protection (RP) tools available (aprons, thyroid protectors, gloves, screens, etc) and their regular use, type and number of procedures performed (diagnostic or therapeutic, complexity level, etc), and RP training level of the specialists. High filtration x-ray beams can entail a decrease of 20% in OD. A regular use of ceiling mounted faceplates can involve dose savings up to 65%. Mean values of dose per procedure for interventional radiologists are something greater (about 15%) than those recorded for cardiologists, except for the dosimeters placed on left forearm and shoulder. The ratio between OD and PD range around 100 μSv/1,000 cGy.cm2. The influence of the staff RP training level on OD is difficult to assess. In the IC Service from the Madrid San Carlos University Hospital (SCUH), PD have been reduced in above 30% and OD in a factor of 3, after running some training programmes. (author)

  1. Medical staff radiation exposure in electrophysiology procedures: First results during biventricular ICD implantation

    International Nuclear Information System (INIS)

    Cardiac resynchronization therapy (CRT) requires a very long fluoroscopy time due to the need to monitor the placement of the device and electrodes inside the patient’s body at every step of the procedure. Aim of this study was to analyse staff X-ray exposure during the intervention, measuring Hp(10) values with electronic dosimeters worn by medical staff. The scattered X-ray field was characterized using a spectrometric CdTe (cadmium-telluride) detector to define the radiation field impinging on the operator and thereby identify the correct dosimeter position for accurate measurement (i.e., above or under the shielding apron). In particular, knowledge of the X-ray spectrum yields information on photon flux and the energy distribution of the X-rays. Dosimetric data were then recorded in a series of 20 consecutive patients, obtaining a first set of Hp(10) data that can be used to estimate the risk for the electrophysiologist performing this procedure.

  2. Evaluation of X-Ray Protective Measurements in Intraoral Radiography Equipped Centers in Yazd

    Directory of Open Access Journals (Sweden)

    D.Goodarzi Pour

    2005-02-01

    Full Text Available Statement of Problem: A few decades have past from using radiographic technology as an accurate paraclinical method and always protective measurements is applicated against ionizing radiation. As dentalradiography is a routine procedure in dentistry the importance of protective strategies is clear.Propose: The aim of this descriptive study is to evaluate the protection principles in centers which haveintraoral radiographic devices in Yazd.Material and Methods: We have considered all three aspects of practitioner, environment and patientprotection using questionnaire and visiting those centers.Results: 33/7% of dental offices ,10 clinics ,3 institution and faculty of dentistry had intraoral radiographicequipments. Stablishment of protection principles for radiographer was favorable. 7.7% of centers had x-ray room with leaded walls, 23.1% had curtain , in 69/2% of centers radiographers stood in correct position anddistance while taking radiograph. Regarding to protection of environment, beams leakage control in 23.1% dental offices, 70% of clinics, all institution and faculty of dentistry have done.Conclusion: Non of the centers used rectangular localizator, thyroid shield, film holder and just some centers used leaded apron in specific circumstances. We have concluded that patient protection constitute less consideration. Generally lack of protective consideration is related to deficient knowledge of operators. Lackof information about protection equipments causes decrease of demanding of these tools and ultimately lack of these equipments in the market.

  3. Optimisation of radio-guided interventional procedures in vascular surgery

    International Nuclear Information System (INIS)

    Vascular surgery has evolved in the past twenty-five years, with the appearance of endovascular techniques which are assuming an increasingly important place in the therapeutic arsenal against peripheral vascular pathologies. These techniques require the use of an X-ray image intensifier (XRII) which exposes the medical personnel, ancillary staff and patient to ionising radiation. The most common arterial damage that can be treated by endovascular techniques concern the thoracic aorta, the abdominal aorta, the visceral arteries, the arteries to the brain, the arteries of the upper and lower limbs. These interventions take place in operating theaters in a surgical environment with the use of a mobile XRII ring and a radiation-transparent carbon surgical table. The radiation protection of the staff and the patient is in any case based, whenever possible, on the use of pulsed techniques, diaphragms, and the wearing of protective aprons and goggles. Depending on the part of the body and the damage being treated, the irradiation dose will be extremely variable. (author)

  4. Pattern of diseases among rice farmers exposed to pesticides in the MUDA area

    International Nuclear Information System (INIS)

    The aim of this study was to find out the pattern of diseases among rice farmers exposed to pesticides in the Muda area, Kedah; and to identify those who suffered from these diseases so that they can be referred to the nearest clinic for treatment. A cross sectional study was conducted in August 1994 to identify the pattern of diseases among rice farmers exposed to pesticides. Cluster Random Sampling was employed and the sample size was 136 farmers. A guided questionnaire was used for assessing the usage of protective clothing, symptoms of the farmers diseases and the distribution of these symptoms. Blood obtained by finger prick was taken for cholesterol level, triglycerides, and blood glucose analysis by using the Reflotron. A medical examination was also conducted. The pattern of diseases detected among the rice farmers shows that 57.4% suffered from pterygium., 81.6% suffered contact dermatitis and 97.1% had central nervous system (CNS) symptoms. Regarding the cholesterol level, 47.1% of rice farmers were found with total cholesterol > 5.2 mmol/L and 40.0% with triglycerides > 2.3 mmol/L. The blood glucose level measured was > 6.1 mmol/L in 55.03% of rice farmers. Usage of protective equipment among rice farmers was: gloves (68.4%), boots (52.2%), goggles (40.4%), apron (38.3%) and face mask (77.2%). (Author)

  5. Survey and analysis of radiation safety management systems at medical institutions. Second report. Radiation measurement, calibration of radiation survey meters, and periodic check of installations, equipment, and protection instruments

    International Nuclear Information System (INIS)

    We carried out a questionnaire survey to determine the actual situation of radiation safety management measures in all medical institutions in Japan that had nuclear medicine facilities. The questionnaire consisted of questions concerning the evaluation of shielding capacity; radiation measurement; periodic checks of installations, equipment, and protection instruments; and the calibration of radiation survey meters. The analysis was undertaken according to region, type of establishment, and number of beds. The overall response rate was 60 percent. For the evaluation of shielding capacity, the outsourcing rate was 53 percent of the total. For the radiation measurements of ''leakage radiation dose and radioactive contamination'' and contamination of radioactive substances in the air'', the outsourcing rates were 28 percent and 35 percent of the total, respectively (p<0.001, according to region and establishment). For the periodic check of radiation protection instruments, the implementation rate was 98 percent, and the outsourcing rate was 32 percent for radiation survey meters and 47 percent for lead aprons. The non-implemented rate for calibration of radiation survey meters was 25 percent of the total (p<0.001, according to region and establishment). The outsourcing rate for calibration of radiation survey meters accounted for 87 percent of the total, and of these medical institutions, 72 percent undertook annual calibration. The implementation rate for patient exposure measurement was 20 percent of the total (p<0.001, according to number of beds), and of these medical institutions 46 percent recorded measurement outcome. (author)

  6. Attitude of the Korean dentists towards radiation safety and selection criteria

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Do [Dept. of Oral and Maxillofacial Radiology and Wonkwang Dental Research Institute, College of Dentistry, Wonkwang University, Iksan (Korea, Republic of); Ludlow, John B. [Graduate Program in Oral and Maxillofacial Radiology, School of Dentistry, University of North Carolina, Chapel Hill (United States)

    2013-09-15

    X-ray exposure should be clinically justified and each exposure should be expected to give patients benefits. Since dental radiographic examination is one of the most frequent radiological procedures, radiation hazard becomes an important public health concern. The purpose of this study was to investigate the attitude of Korean dentists about radiation safety and use of criteria for selecting the frequency and type of radiographic examinations. The study included 267 Korean dentists. Five questions related to radiation safety were asked of each of them. These questions were about factors associated with radiation protection of patients and operators including the use of radiographic selection criteria for intraoral radiographic procedures. The frequency of prescription of routine radiographic examination (an example is a panoramic radiograph for screening process for occult disease) was 34.1%, while that of selective radiography was 64.0%. Dentists' discussion of radiation risk and benefit with patients was infrequent. More than half of the operators held the image receptor by themselves during intraoral radiographic examinations. Lead apron/thyroid collars for patient protection were used by fewer than 22% of dental offices. Rectangular collimation was utilized by fewer than 15% of dental offices. The majority of Korean dentists in the study did not practice radiation protection procedures which would be required to minimize exposure to unnecessary radiation for patients and dental professionals. Mandatory continuing professional education in radiation safety and development of Korean radiographic selection criteria is recommended.

  7. Influence of standing positions and beam projections on effective dose and eye lens dose of anaesthetists in interventional procedures.

    Science.gov (United States)

    Kong, Y; Struelens, L; Vanhavere, F; Vargas, C S; Schoonjans, W; Zhuo, W H

    2015-02-01

    More and more anaesthetists are getting involved in interventional radiology procedures and so it is important to know the radiation dose and to optimise protection for anaesthetists. In this study, based on Monte Carlo simulations and field measurements, both the whole-body doses and eye lens dose of anaesthetists were studied. The results showed that the radiation exposure to anaesthetists not only depends on their workload, but also largely varies with their standing positions and beam projections during interventional procedures. The simulation results showed that the effective dose to anaesthetists may vary with their standing positions and beam projections to more than a factor of 10, and the eye lens dose may vary with the standing positions and beam projections to more than a factor of 200. In general, a close position to the bed and the left lateral (LLAT) beam projection will bring a high exposure to anaesthetists. Good correlations between the eye lens dose and the doses at the neck, chest and waist over the apron were observed from the field measurements. The results indicate that adequate arrangements of anaesthesia device or other monitoring equipment in the fluoroscopy rooms are useful measures to reduce the radiation exposure to anaesthetists, and anaesthetists should be aware that they will receive the highest doses under left lateral beam projection. PMID:24795393

  8. Dual guidance (CT and fluoroscopy) vertebroplasty: radiation dose to radiologists. How much and where?

    International Nuclear Information System (INIS)

    The goal of this study was to evaluate the radiation received by the practitioner when performing percutaneous vertebroplasty guided by CT and fluoroscopy for specific anatomical sites: orbits, hands, ankles, and thorax (under lead-lined apron). Twenty-four vertebroplasties were performed on 18 patients. The anatomical site that was most exposed to radiation was the right hand (0.37 mSv on average). This study demonstrates a significant correlation between the irradiation dose and fluoroscopy duration, reflecting both the quantity of primary-beam radiation and backscattered radiation. The right hand (P = 0.03), left hand (P = 0.02), and the left orbit (P < 0.0001) are the anatomical zones that are the most affected by the combination of these two types of radiation, with cumulative irradiation doses of 0.45, 0.2, and 0.14 mSv, respectively. There was a significant correlation between the patient weight and radiation of the left hand (P = 0.03), the left orbit (P = 0.03), and the thorax (P = 0.02), confirming the major influence of backscattered radiation. The most irradiated anatomical sites limiting the number of interventions are the left orbit and the right hand. (orig.)

  9. The Yermak Plateau in the Arctic Ocean in the light of reflection seismic data—implication for its tectonic and sedimentary evolution

    Science.gov (United States)

    Geissler, W. H.; Jokat, W.; Brekke, H.

    2011-12-01

    The separation of Northeast Greenland and Svalbard is the result of large-scale strike slip movements during Cenozoic times. Geological evidence for these movements can be found onshore both on North Greenland and Svalbard. However, the role of the submarine Yermak Plateau (YP) in this process is unclear. The compilation of available multichannel reflection and wide-angle seismic data give new insights into the sedimentary and crustal structure and evolution of the plateau. The flat surface of the present-day plateau is a quite young feature. Up to 2 km of Cenozoic sediments cover a rough basement, which show similarities to the rough topography and strike of geological structures of Spitsbergen Island. In some basins more than 4 km of sedimentary rocks could be mapped. The most pronounced structure is the Sverdrup Bank, which appears to be part of a larger crustal block. P-wave velocities of about 4.5 km s-1 derived from sonobuoy data indicate that its uppermost part is most probably composed of sedimentary or volcanic rocks. We have made a correlation of previously defined seismic units across the YP to outline the history of sediment deposition in the area. The existing graben structures on the plateau might have provided early shallow pathways for water exchange between the Arctic and the Atlantic Oceans. A chaotic sedimentary apron east of the Sverdrup Bank and bright reflections near the Mosby Seamount interpreted as magmatic sills suggest tectonic and magmatic events during the Miocene.

  10. Accidental over-exposure from dental X-ray equipment

    International Nuclear Information System (INIS)

    A description is given of an unusual dental X-ray procedure which resulted in accidental over-exposure both to the dentist and to several of his patients when a short-circuit was present in newly-installed equipment. The short-circuit by-passed the exposure control and energized the tube for certain orientations of the X-ray tube. The dentist left the patients, who wore protective aprons, to initiate the exposure themselves, using the control button. Although the warning lights were on, the dentist was not present in the room during the exposure, and the over-exposures were only detected when the developed X-ray films were found to be completely blackened. A reconstruction of the procedure enabled estimates to be made of the dose equivalents to the dentist's body and to the skin of the head, the eyes and the gonads of the patients. The dentist had overlooked several of basic principles recommended in the Code of Practice for the Protection of Persons against Ionizing Radiations from Medical and Dental Use (1972). It is pointed out that incidents involving failure of dental equipment (usually the timer mechanism) are not infrequent. (U.K.)

  11. Dental radiographic exposures in Recife - Brazil

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the operating conditions of x-ray equipment installed in dental clinics in Recife, Brazil, as well as to evaluate the implementation of radiation protection procedures. The results showed that 42% of the inspected units present field diameters out of the range of values recommended by either national or international radiation protection organizations. Non-invasive tests performed in the x-ray units indicated that the discrepancy between the preset time and the true irradiation time was higher than 10% in 69% of the cases. The discrepancy between the preset and the applied kilo voltage, on the other hand, was higher than 10% in 35% of the inspected units. The survey indicated that the majority of the clinics do not use either lead aprons or collars for patients and that films are processed manually, without using timers or thermometers. The test made to verify the adequacy of the film processing box showed that 75% of them had poor light filtration capacity. In view of the results obtained it is strongly recommended that a quality control program be implemented in dental radiological clinics in Recife (author)

  12. A survey of radiologic practices in dental installations in Recife

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the operating conditions of the dental x-ray equipment installed in Recife, as well as, evaluate the radioprotection procedures at the dental clinics. The study consisted of: a) visual inspection of the x-ray unit, b) complete registration of the unit's characteristic, i.e. manufacturer, model, age, collimation type,FSD; c) measurement of the kVp, exposure time and surface dose, d) evaluation of the film processing conditions, and e) inspection of the radiation protection items available for the patient and personnel. The results showed that 42% of the inspected units presented fields diameters larger than the limits values than the limits values recommended by either national or international radiation protection organizations. The discrepancy between the present time and the ''true'' irradiation time was higher than 10% in 69% of the cases. The discrepancy between the present and the applied kilovoltage, on the other hand, was higher than 10% in 35% of the inspected units. The majority of the clinics do not have available either lead aprons or collars patients. Films are processed manually without using timers or thermometers. The test made to verify the adequacy of the film processing box showed that 75% of them had poor light filtration capability. In view of the result obtained, it is strongly recommended that a quality control program be implemented in dental radiologic clinics in Recife

  13. A limited survey of dental x-ray units and protection in Korea

    International Nuclear Information System (INIS)

    In dental roentgenograph it is of mutual benefit to the patient and the dentist to use the minimum amount of radiation capable of producing roentgenograms with maximum interpretive information. Recent increases in the number of diagnostic x-ray examinations made in this country have caused attention to be paid to the quantity of radiation delivered to the population and operator. The purposes of this study was to assess the quality of dental x-ray units, the amount of films, the average processing procedures and the radiation protection methods in Korea. The results were as following: 1. Most of radiation generating system were used in low voltage such as 60 Kvp, 10 mA. 2. High sensitivity films such as 'D' group of Kodak or Rinn were mainly used and average 14. 7 films used per weeks. 3. Some dentists practiced visual processing technic in simple dark room, and others used instant films.4. 68.26% of patient held the film themselves, but 27.30% were assisted by dentists film holding. 5. Irradiation protection method, 7.85% of dentists had protection equipment such as protective barrier, 2.73% wore protective apron, 27.9% made it a rules to avoid beam, and 7.51% used to maintain a distance from the radiation source.

  14. Effect of changes in technical parameters in radiological safety

    International Nuclear Information System (INIS)

    This work analyzes the generation of secondary radiation that affects the professionals of health during interventional X ray procedures in first level hospitals. The research objectives were, on the one hand, to quantify the amount of radiation and to compare it with norms in force with respect to magnitudes, and on the other hand to evaluate the elements of protection used. The measurements will help to improve the radiological safety, to assess the eventuality of risks and, in the last term, to the possibility of norms modification for the improvement of the protection, especially that of the personnel who daily make a certain amount of interventional procedures guided by radiation, like angiographic cine applications, using continuous or pulsed fluoroscopy. The motivation of the study is in the suspicion that present interventionism is made with a false sensation of safety, based only in the use of lead apron and protection elements incorporated in the equipment by the manufacturer, nevertheless not always the health personnel are conscious that an excessive proximity with the tube and the patient body becomes a risky source of secondary and scattered radiation. The obtained results allow us to demonstrate the existence of conditions of risk, even possible iatrogenic events, in particular when the procedures imply the use of certain techniques of radiographic exploration, thus reaching the conclusion that the radiographic methodology must be changed in order to rationalize so much?. In order to achieve this we propose modifications to the present norms and legislation referred to the radiological safety in Chile

  15. Occupational Hepatitis B Exposure: A Peek into Indian Dental Students’ Knowledge, Opinion, and Preventive Practices

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar

    2015-01-01

    Full Text Available Objective. To determine the level of knowledge, opinions, and preventive practices followed by dental students against Hepatitis B. The study also explored if any correlation existed between knowledge, opinion, and preventive practices score. Materials and Methods. A cross-sectional study was conducted in a dental teaching institution. The subjects comprised 216 dental students. The study was conducted using a pretested, self-administered questionnaire. The questionnaire was prepared to assess knowledge, opinion, and preventive practices against Hepatitis B. Kruskal-Wallis and Kendall Tau test were performed. Results. The study found that only 44.4% of the students were vaccinated with Hepatitis B vaccine. 59.3% of the students reported washing their hands after contact with patient’s body fluids. 63.9% used personal protective measures like facemask, aprons, head cap, eye shields, and so forth, while treating patients. Median knowledge, opinion, and practice scores were found to be 5.00, 3.00, and 3.00, respectively. Significant correlation was obtained between knowledge and preventive practices score (r=0.385, p value <0.0001. Conclusion. Effective measures need to be taken to improve preventive practices of the students to prevent them from risk of Hepatitis transmission. Mandatory vaccination against Hepatitis B needs to be implemented.

  16. Metalogenic study of the uraniferous ore deposit at La Coma, Municipio of General Bravo, N.L. Mexico

    International Nuclear Information System (INIS)

    The uraniferous ore deposit at la Coma is located in a sandy-clayish sequence of the cold formation (non marine member) of the middle oligocene under peneconcordant lenses within a sandy body, situated on the North flank of a microdelta formed by small streams which ran from West to East. The metalogenic study of this ore deposit, permits us to establish mineralization controls and guides for the optimization of the uranium prospecting in the miogeoclinical of the Gulf of Mexico setting. The study was carried out on the basis of sedimentalogic and metalogenic criteria, and it was found that the mineralization process seems to be related to the formation and filling of a paleochannel which cut the microdelta permeable beds. The uraniferous solutions migrated through the conglomeratic filling of the paleochannel and reached this way the permeable horizons of the microdelta, where they infiltrated adopting a pattern like an apron. In the sites where the solutions reached sandy lenses rich in organic matter, the soluble compounds containing the uranium suffered a decomposition with the consequent absorption of the uranium by the organic matter, due to the decrease of the pH value. In conclusion, the favorableness of the environment for mineralization is defined by the convergence of the described paleo-geomorphologic elements. (author)

  17. Evaluation of radiation exposure in interventional radiology (IR) using active personal dosimeters (APD); Evaluierung der Strahlenexposition in der Interventionellen Radiologie (IR) mit Hilfe von Aktiv-Personen-Dosimetern (APD)

    Energy Technology Data Exchange (ETDEWEB)

    Neugschwandtner, K. [KH Hietzing mit NZ Rosenhuegel, Wien (Austria). Inst. fuer Krankenhausphysik; TU Wien (Austria). Atominstitut; Freund, R. [KH Hietzing mit NZ Rosenhuegel, Wien (Austria). Inst. fuer Krankenhausphysik; Mertikian, G. [KH Hietzing mit NZ Rosenhuegel, Wien (Austria). Inst. fuer Radiologie; Poljanc, K. [TU Wien (Austria). Atominstitut; Ibi, B. [KA Rudolfstiftung, Wien (Austria). Stabstelle Medizinphysik

    2015-07-01

    Increased awareness of high personal dose exposure of medical staff in interventional radiology (IR) demands an assessment of radiation protection procedures. Mandatory dose monitoring systems do not allow to relate dose to specific actions of the staff as they just accumulate a total dose per month. Doses of head and limbs are expected to be high as those body parts which are not protected by the lead apron. We decided to use a measuring system by Unfors, RaySafe i2 which is built for real- time- dosimetry of scattered radiation in pulsed X-ray fields. An increased dose of the body side closer to the X-ray source (left body side) was detected. This is due to the position and the posture of the radiologist during intervention. Separating the phases of digital subtraction angiography (DSA) from those of fluoroscopy allowed not only to list the separate accumulated doses, but showed as well a big difference in dose rate. The measurements revealed the need of an improvement of common radiation protection, especially while DSA.

  18. Protective equipment of radiological protection and the worker wear; Equipamento de protecao radiologica e o desgaste do trabalhador

    Energy Technology Data Exchange (ETDEWEB)

    Cassia, Flor Rita de; Huhn, Andrea, E-mail: flor@ifsc.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Santa Catarina (IFSC), Florianopolis, SC (Brazil); Lima, Gelbcke Francine, E-mail: fgelbcke@ccs.ufsc.br [Universidade Federal de Santa Catarina (PEN/UFSC), Florianopolis, SC (Brazil). Programa de Pos-Graduacao em Enfermagem

    2013-11-01

    This qualitative research with workers of seven hemodynamic service of Santa Catarina, Brazil aimed to analyze the use of radiological protection equipment (RPE), as well as wear to the health of workers who use these causes. The study was conducted between March 2010 and November 2010, totaling approximately 30 hours of observations. Results showed resistance to the use of RPE and also showed wear to workers' health, mainly due to the weight and discomfort they cause, as may weigh 7-9 pounds, depending on the model used. Evidenced also the absence of workers due herniated disc, back pain, and other musculo skeletal problems. These complaints, in addition to being related to the use of these protective gear also related with the time that workers remain standing for long periods on certain procedures, such as angioplasty. Given these results, the research recommended the use of these devices with materials, that are already being produced, making lighter aprons, thus avoiding fatigue and back pain and also provide greater comfort by reducing workers' resistance to its use and its adverse consequences.

  19. Evaluation of doses to staff involved in interventional cardiology in two Khartoum hospitals

    International Nuclear Information System (INIS)

    In interventional cardiac procedures, staff operates near the patient in a non-uniformly scattered radiation field. Consequently, workers may receive, over a period of time, relatively high radiation doses. The measurement of individual doses to personnel becomes critical due to the use of protective devices and, as a consequence of the large number of methods proposed to assess the effective dose, In this study, staff doses were measured in two cardiac centers: Ahmed Gasim Hospital and Cardiac Center, Khartoum. The objective was to measure personal dose equivalent and accordingly estimate the effective dose which is received by staff in interventional cardiology. Measurements were performed using electronic personal dosimeters (EPDs) worn over lead apron during the examination and were read immediately following each examination. A total number of 40 radiation worker were monitored for a period of two weeks. The highest doses received by the cardiologist followed by nurses and then X-ray technicians. Staff received mean effective doses that ranged from 24 to 110 μSv estimated for four weeks. Recommendations on how to reduce staff doses in interventional cardiology are presented. (Author)

  20. Evaluation of quality assurance of some diagnostic x-ray machines in Khartoum state

    International Nuclear Information System (INIS)

    Availability and the use of x-ray equipment in both private and government hospitals are on the increase today in Khartoum state. Quality control of such equipment is of particular importance to prevent avoidable high doses, radiation leakages and to ensure dose optimization. The results of quality control in this study indicated that: all centers were within the k Vp reproducibility level (5%). At k Vp 50 and 60 there were 93% of centers within the limit and 7% were out. For 70, 81 and 90 k Vp all centers were within the limit. 73% of centers were within the level of HVL test, but 27% of them were out of the limit 80% of centers had a linear relationship between m As and dose, but three centers had no linear relationship. For time reproducibility 80% of centers were within the time reproducibility and 13% were out of limit. The beam on control and indicator were available and functional for all centers. The warning light was present in one center. But 93% of centers, but 20% of centers had no window lead glass. Lead aprons were available and functional in all centers. The gloves were available and functional in 33% of centers. But in 67% of centers they were not present. Gonads shields were present in 33% of centers, but not available for 67% of centers.(Author)

  1. Tritium distributions on tungsten and carbon tiles used in the JET divertor

    Science.gov (United States)

    Hatano, Y.; Yumizuru, K.; Likonen, J.; Koivuranta, S.; Ikonen, J.; Contributors, JET

    2016-02-01

    Tritium distributions on the W-coated divertor tiles used with Be wall in JET 2011-2012 ITER-like wall (JET-ILW) campaign were measured using an imaging plate (IP) technique. The high intensity of photo-stimulated luminescence (PSL) from IP was observed at the regions covered by deposited Be layers. However, the PSL intensity was not simply proportional to the thickness of the deposited Be layers; the shadowed region of Tile 4 showed the highest PSL intensity though the thickness of deposited Be layer on this region was smaller than that on Tile 0 and the apron of Tile 1 by an order of magnitude. These observations indicated the influence of impurities such as oxygen on tritium retention in the deposited Be layers. The C tiles used in the 2007-2009 JET carbon wall (JET-C) campaign were also examined. The high PSL intensity was observed for the regions covered with deposited C layers in this case. The area of tile surfaces covered by the deposited tritium-rich layers on the W-coated-tiles used in the JET-ILW campaign was significantly smaller than that on the C tiles used in the JET-C campaign.

  2. SMALL-SCALE MODELING OF DYNAMIC FACILITIES FOR PROTECTION OF HYDROSYSTEM TAILRACES

    Directory of Open Access Journals (Sweden)

    Kuznetsova Y. A.

    2015-11-01

    Full Text Available To study the formation of plunge basin in the Cheboksary hydroplant, we used a scale model of the spillway dam and all structures in the tailrace, installed in the slot flume. When we passed the flow corresponding to the diversion flow of the hydroplant with a glance to the modeling scale, it was found that the plunge basin was formed behind the end fixing of the spillway apron. To research the dynamic facilities of hydrosystem tailrace protection against erosion, we used a small glass flume with a model of the roundcrested weir. For the experiment, the water-surface elevations were built in the flume without the weir, and the uniform motion area was established. In MathCAD software environment, the curve of the flow of measuring rectangular weir of the flume was created. Because of measurements, the curve of water surface by the flow motion through the round-crested weir was made. As the main criterion for modeling, the criterion of Froude was selected. Scale of modeling of flow parameters was determined. For testing, models of hydrodynamic profile and sail structure with streamforming sluice valves were built. The process of sand washout from the flume bottom and formation of the bottom ridges when installing the profile was photographed. Impact of the profile on the flow and its relation with the formation of the bottom topography were studied. Full-scale values of geometric parameters of the bottom ridges and their movement velocity were established as well

  3. Tectonic controls on the geomorphic evolution of alluvial fans in the Piedmont Zone of Ganga Plain, Uttarakhand, India

    Indian Academy of Sciences (India)

    Pradeep K Goswami; Charu C Pant; Shefali Pandey

    2009-06-01

    The Piedmont Zone is the least studied part of the Ganga Plain.The northern limit of the Piedmont Zone is defined by the Himalayan Frontal Thrust (HFT)along which the Himalaya is being thrust over the alluvium of the Ganga Plain.Interpretation of satellite imagery,Digital Terrain Models (DTMs)and field data has helped in the identification and mapping of various morpho-tectonic features in the densely forested and cultivated Piedmont Zone in the Kumaun region of the Uttarakhand state of India.The Piedmont Zone has formed as a result of coalescing alluvial fans,alluvial aprons and talus deposits.The fans have differential morphologies and aggradation processes within a common climatic zone and similar litho-tectonic setting of the catchment area. Morphotectonic analysis reveals that the fan morphologies and aggradation processes in the area are mainly controlled by the ongoing tectonic activities.Such activities along the HFT and transverse faults have controlled the accommodation space by causing differential subsidence of the basin,and aggradation processes by causing channel migration,channel incision and shifting of depocentres.The active tectonic movements have further modified the landscape of the area in the form of tilted alluvial fan,gravel ridges,terraces and uplifted gravels.

  4. Applying fluvial geomorphological riffle-pool sequences concept when rebuilding the existing drop hydraulic structure

    Directory of Open Access Journals (Sweden)

    Artur RADECKI-PAWLIK

    2015-01-01

    Full Text Available The paper deals with the problem of  rebuilding  the existing water straight drop  structure in Brenna on the Brennica river (Polish Carpathian mountains, which was changed into the rapid hydraulic structure. The technical project was set up in 1988 and finished in the same year. The structure was rebuilt in the field in the early autumn of 1990. One of the concepts of applied fluvial geomorphological solution was used to improve the river channel bed condition. In that case it was found that the existing hydraulic structure reducing river slope and stabilizing river bed can be changed without any harm in to semi-natural riffle structure which could be tolerated by river and organisms living in.  Artificial roughness of the slope plate of the rapid hydraulic structure was obtained by placing cobbles along all the slope apron of the structure. The diameter of cobbles was calculated applying various methods, and the optimum value for that dimension was chosen. The cobbles, used for rebuilding purposes, were taken directly from the riverbed, so that the structure is environmentally similar to the site. All work was done due to European Framework Directive for Rivers.

  5. Dose equivalent to fingertips of nuclear medicine personnel

    International Nuclear Information System (INIS)

    One of the most frequently used diagnostic nuclear medicine procedures is done with 99 mTc radionuclides. Activities of radionuclides being administered may be even as high as 1 GBq. Medical personnel remain under constant dosimetric surveillance and are protected from radiation by using personal and permanent shields (like lead aprons, gloves or lead glass). Owing to this protection, effective doses are low, ranging within several per cent of the limit value. The situation is, however, quite different if one considers the exposure to hands of the personnel handling the radiopharmaceuticals. All isotope handling procedures, such as elution of technetium, preparation of radiopharmaceuticals or application of the latter to the patients are performed manually, with little use of manipulators. As a result, the dose to the hands during the handling of radioisotopes may be significant from the point of view of radiological protection. Our research leads to the following conclusions: 1. Fingertips of the middle finger, index and thumb are the most exposed to ionizing radiation parts of the hand. 2. The limit of the equivalent dose to the skin (500 mSv) may be exceeded, on the fingertips in particular. 3. The considerable dose reduction to hands exposed to ionizing radiation may be achieved by improving procedures through the work automation for example. (authors)

  6. Root parsley protection against damping off

    Directory of Open Access Journals (Sweden)

    Bogdan Nowicki

    2013-12-01

    Full Text Available Seed treatment ofroot parsley was done to protect Petroselinum santivum seedlings against damping off. Fungicides used as seed dressers were applied in 3 doses: 3, 5 and 10 g/kg. Seeds were treated with 7 dressers (Table l used separately and in mixture with 3 g/kg of Rovral 50 WP (50% iprodione and 1 g/kg of Apron 35 SD (35% metalaxyl. Two seed samples of Berlińska cultivar were used: first sample was strongly infected by Alternaria petroselini and A.radicina both 27,6% and also by Fusarium spp. 5,4% (Test I, and second sample revealed lower percentage of infection 4,6% and 1,2%, respectively (Test II. The experiments were conducted under laboratory, glasshouse and field conditions. Complete seedlings protection in all experiments was achieved for treatments when fungicide mixture was used in the highest dose (10 g/kg. Decrease of fungicides concentrations were connected with lower effectiveness of disease control. No phytotoxic effects of the tested fungicide mixtures were observed under the glasshouse or field conditions.

  7. Mars and earth - Comparison of cold-climate features

    Science.gov (United States)

    Lucchitta, B. K.

    1981-01-01

    On earth, glacial and periglacial features are common in areas of cold climate. On Mars, the temperature of the present-day surface is appropriate for permafrost, and the presence of water is suspected from data relating to the outgassing of the planet, from remote-sensing measurements over the polar caps and elsewhere on the Martian surface, and from recognition of fluvial morphological features such as channels. These observations and the possibility that ice could be in equilibrium with the high latitudes north and south of + or - 40 deg latitude suggest that glacial and periglacial features should exist on the planet. Morphological studies based mainly on Viking pictures indicate many features that can be attributed to the action of ice. Among these features are extensive talus aprons; debris avalanches; flows that resemble glaciers or rock glaciers; ridges that look like moraines; various types of patterned ground, scalloped scarps, and chaotically collapsed terrain that could be attributed to thermokarst processes; and landforms that may reflect the interaction of volcanism and ice.

  8. Geologic framework for the national assessment of carbon dioxide storage resources: Alaska North Slope and Kandik Basin, Alaska: Chapter I in Geologic framework for the national assessment of carbon dioxide storage resources

    Science.gov (United States)

    Craddock, William H.; Buursink, Marc L.; Covault, Jacob A.; Brennan, Sean T.; Doolan, Colin A.; Drake II, Ronald M.; Merrill, Matthew D.; Roberts-Ashby, Tina L.; Slucher, Ernie R.; Warwick, Peter D.; Blondes, Madalyn S.; Freeman, P.A.; Cahan, Steven N.; DeVera, Christina A.; Lohr, Celeste D.

    2014-01-01

    This report presents fourteen storage assessment units (SAUs) from the Alaska North Slope and two SAUs from the Kandik Basin of Alaska. The Alaska North Slope is a broad, north-dipping coastal plain that is underlain by a thick succession of sedimentary rocks that accumulated steadily throughout much of the Phanerozoic during three major tectonic sequences: the Mississippian through Triassic Ellesmerian sequence, the Jurassic through Lower Cretaceous Beaufortian sequence, and the Cretaceous and Tertiary Brookian sequence. Stratigraphic packages associated with all three of these tectonic sequences are suited to geologic carbon dioxide (CO2) sequestration. The lower part of the Ellesmerian sequence contains five potential SAUs, two of which have reservoirs within the Endicott Group and three of which have reservoirs within the Lisburne Group. Another potential SAU has sandstone-prone reservoir units interbedded with the upper part of the Ellesmerian Shublik Formation and the Beaufortian Kingak Shale. The Brookian sequence contains eight potential SAUs that have reservoirs that are defined by the various Cretaceous and Tertiary deltaic topset strata of the Colville foreland basin as well as associated slope aprons and submarine turbidite fan complexes.

  9. Detection and Genotyping of Leuconostoc spp. in a Sausage Processing Plant.

    Science.gov (United States)

    Padilla-Frausto, J J; Cepeda-Marquez, L G; Salgado, L M; Iturriaga, M H; Arvizu-Medrano, S M

    2015-12-01

    Some Leuconostoc spp. have the ability to produce slime and undesirable compounds in cooked sausage. The objectives of this research were to identify Leuconostoc sources in a Vienna-type sausage processing plant and to evaluate the genetic diversity of the isolated strains. Three hundred and two samples of sausage batter, sausages during processing, spoiled sausage, equipment surfaces, chilling brine, workers' gloves and aprons, and used casings were collected (March to November 2008 and February to April 2010) from a sausage processing plant. Lactic acid bacteria (LAB) were quantified, and Leuconostoc were detected using PCR. Strains were isolated and identified in Leuconostoc-positive samples. Leuconostoc strains were genotyped using randomly amplified polymorphic DNA and pulsed-field gel electrophoresis. LAB content of nonspoiled and spoiled sausage ranged from sausages showed the same genotype. One L. lactis genotype included strains isolated from spoiled sausages analyzed in April 2008 and March to April 2010. Equipment and conveyor belts constitute Leuconostoc contamination sources. Leuconostoc persistence in the sausage processing environment and in the final product suggests the existence of microbial reservoirs, possibly on equipment surfaces. PMID:26613911

  10. Geologic siting considerations for the disposal of radioactive waste into submarine geologic formations

    International Nuclear Information System (INIS)

    The most desirable characteristics of the host medium are: (1) low permeability and high Kd; (2) ability to self heal, i.e., be visco-elastic in response to dynamic stress; (3) stability under predicted thermal loading; (4) a low content of organic matter, i.e., be well oxidized. The submarine geologic formation that appears to best satisfy the above criteria is abyssal red clay. Depending on organic interactions and permeability considerations, light brown deep-sea clays with 20 to 40% CaCO3 also may be suitable. Increasingly organic-rich, more permeable biogenic oozes appear less suitable, with turbidite sands and silts least desirable of all. Ocean regions excluded at the present time are: (1) areas less than 4000 meters deep; (2) the continental margin including fans, deltas, aprons, cones; (3) proximal portions of abyssal plains; (4) all fracture zone abyssal plains; (5) all submarine canyon-levee systems; (6) areas covered with less than 50 meters of sediment; (7) areas greater than 100 nautical miles from plate boundaries; (8) areas with ice-rafted debris; (9) major shipping lanes, cable routes and defense installations; (10) seafloor regions below areas of high biological productivity; and (11) approximately one third of the world's ocean floor satisfy these criteria

  11. Geophysical characterization of permafrost terrain at Iqaluit International Airport, Nunavut

    Science.gov (United States)

    Oldenborger, Greg A.; LeBlanc, Anne-Marie

    2015-12-01

    Iqaluit International Airport presently suffers from instabilities and subsidence along its runway, taxiways and apron. In particular, asphalt surfaces are significantly impacted by settlement and cracking. These instabilities may be related to permafrost, permafrost degradation and associated drainage conditions. Low induction number electromagnetic measurements along with galvanic and capacitive electrical resistivity surveys were performed over selected areas within the airport boundary and in the near vicinity to assist with permafrost characterization and to investigate active permafrost processes. Electrical resistivity images suggest distinct electrical signatures for different terrain units and sediment types, and for ice-rich material including ice wedges. Anomalous regions are identified that are coincident with localized settlement problems. Repeated resistivity maps reveal seasonal changes indicative of high unfrozen water content and freeze/thaw of groundwater beneath airport infrastructure in distinct regions related to surficial geology. Even with continuous permafrost and cold permafrost temperatures, the resistivity models reveal anomalously conductive material at depth that is not obviously correlated to mapped surficial sediments and that may represent thaw susceptible sediments or significant unfrozen water content.

  12. Verification of lead equivalent of shielding materials used in diagnostic radiology

    International Nuclear Information System (INIS)

    The verification of lead equivalent of shielding materials used in diagnostic radiology is crucial to ensure that they fulfil their task in protecting both patient and personnel as well as the public from ionising radiation. In this paper, a simple procedure to verify the lead equivalent of radiation protection devices supplied by local vendors such as lead glass, concrete, barium plastered concrete and lead apron was established. An industrial X-ray machine Philips Model MCN165 and X-ray detector systems Innovision Model 451P and Radcal Radiation Monitor Model 2026C with 180 and 6 cubic centimetre ionisation chambers were used. A direct comparison between the attenuation of X-rays by the protective devices and that of actual lead sheets allows the value of the lead equivalent to be determined. Both theoretical and experimental approach are used to obtain the calibration curve to calculate the lead equivalent of the protective devices. Lead equivalents of the protective devices at various diagnostic X-ray beam qualities namely 50 kV, 80 kV, 100 kV, 125 kV and 150 kV were determined. Results obtained showed that the protective devices tested complied with the Ministry of Health's (MOH) requirement and can be used for shielding and protective purposes in diagnostic radiology. (Author)

  13. Characterization of submarine canyon bathymetries in northern Ionian Sea, Italy, using sediment geochemical variation induced by transportation distance and basin depth

    Science.gov (United States)

    Francesco, Perri; Tohru, Ohta; Salvatore, Critelli

    2015-07-01

    Geochemical data of marine mud sediments collected from the Esaro, Neto and Corigliano canyons in the northern Ionian Sea (southern Italy) were investigated in order to characterize canyon bathymetry types. Mud sample compositions analyzed by the principal component analysis (PCA) provided useful information for the morphology of the depositional area of the northern Ionian Sea. The use of sediment geochemical data as well as transportation distance and depth as input variables for PCA enabled the extraction of following latent variables: basin depth (PC1), sedimentation rate (PC2) and transportation distance (PC3). Based on these results, we further developed geochemical indices that can estimate basin depth (F1), sedimentation rate (F2) and transportation distance (F3); these functions can be solely calculated from the elemental concentration data of the mud samples. Since these F1, F2 and F3 functions are mathematically independent variables, they facilitate more precise characterization of individual canyon types. That is, the Esaro Canyon is regarded as a sediment-starved deep canyon characterized by a single source area; the Neto Canyon can be seen as a deeply sloped submarine apron system and sediments are mainly supplied by the sediment gravity flows; the Corigliano Canyon is characterized by multiple sources and moderately sloped system, whose sediments disperse mainly by traction currents. These interpretations are concordant with the basin bathymetry of the studied area. Therefore, F1, F2 and F3 functions might be applicable to any oceanic basins.

  14. Evidence of (pre-) historic to modern landscape development and land use history in Lower Lusatia (Brandenburg, Germany)

    Science.gov (United States)

    Nicolay, Alexander; Raab, Alexandra; Raab, Thomas

    2014-05-01

    In the apron of three active lignite opencast pits in Lower Lusatia (Brandenburg, Germany), archaeological survey trenches were investigated in areas where Quaternary aeolian sand deposits are widespread. The investigated palaeoenvironmental archives in Jänschwalde, Cottbus-Nord and Welzow contain evidence of fluvial and aeolian morphodynamics, soil formation and agricultural land use from (pre-)historic to modern times. To study the age and the causes of sand drifting and landform stabilization, standard soil physical and chemical laboratory analyses as well as optically stimulated luminescence (OSL) and radiocarbon dating (14C) were carried out. Two main sedimentological units were identified: Unit 1 consists of glacio-fluvial and Late Weichselian aeolian sands representing the parent material for the native Podsol-Braunerde and Podsol development, while Unit 2 represents the Late Holocene aeolian deposits. Four periods of Late glacial and Holocene aeolian activity and three phases of geomorphological stability have been identified: (i) Aeolian sedimentation during the Late glacial, (ii) Mesolithic reactivation of aeolian processes, (iii) soil formation until Late Roman Iron Age settlers intensified the agricultural land use, (iv) intensive drift sand formation during the High Middle Ages due to agricultural expansion, (v) stabilization of the drift sands and weak soil formation, (vi) reactivation of aeolian processes due to the increasing wood consumption and charcoal production from the early 16th until the mid-19th century, (vii) surface stabilization and formation of Regosols since the mid-19th century due to afforestation.

  15. Protective equipment of radiological protection and the worker wear

    International Nuclear Information System (INIS)

    This qualitative research with workers of seven hemodynamic service of Santa Catarina, Brazil aimed to analyze the use of radiological protection equipment (RPE), as well as wear to the health of workers who use these causes. The study was conducted between March 2010 and November 2010, totaling approximately 30 hours of observations. Results showed resistance to the use of RPE and also showed wear to workers' health, mainly due to the weight and discomfort they cause, as may weigh 7-9 pounds, depending on the model used. Evidenced also the absence of workers due herniated disc, back pain, and other musculo skeletal problems. These complaints, in addition to being related to the use of these protective gear also related with the time that workers remain standing for long periods on certain procedures, such as angioplasty. Given these results, the research recommended the use of these devices with materials, that are already being produced, making lighter aprons, thus avoiding fatigue and back pain and also provide greater comfort by reducing workers' resistance to its use and its adverse consequences

  16. Optimisation of radio-guided interventional procedures in vascular surgery; Optimisation des procedures interventionnelles radioguidees en chirurgie vasculaire

    Energy Technology Data Exchange (ETDEWEB)

    Sabatier, Jean [Service de chirurgie vasculaire, Clinique de l' Europe, 73 Boulevard de l' Europe, 76100 Rouen (France)

    2011-07-15

    Vascular surgery has evolved in the past twenty-five years, with the appearance of endovascular techniques which are assuming an increasingly important place in the therapeutic arsenal against peripheral vascular pathologies. These techniques require the use of an X-ray image intensifier (XRII) which exposes the medical personnel, ancillary staff and patient to ionising radiation. The most common arterial damage that can be treated by endovascular techniques concern the thoracic aorta, the abdominal aorta, the visceral arteries, the arteries to the brain, the arteries of the upper and lower limbs. These interventions take place in operating theaters in a surgical environment with the use of a mobile XRII ring and a radiation-transparent carbon surgical table. The radiation protection of the staff and the patient is in any case based, whenever possible, on the use of pulsed techniques, diaphragms, and the wearing of protective aprons and goggles. Depending on the part of the body and the damage being treated, the irradiation dose will be extremely variable. (author)

  17. An Algorithm for Managing Aircraft Movement on an Airport Surface

    Directory of Open Access Journals (Sweden)

    Giuseppe Maresca

    2013-08-01

    Full Text Available The present paper focuses on the development of an algorithm for safely and optimally managing the routing of aircraft on an airport surface in future airport operations. This tool is intended to support air traffic controllers’ decision-making in selecting the paths of all aircraft and the engine startup approval time for departing ones. Optimal routes are sought for minimizing the time both arriving and departing aircraft spend on an airport surface with engines on, with benefits in terms of safety, efficiency and costs. The proposed algorithm first computes a standalone, shortest path solution from runway to apron or vice versa, depending on the aircraft being inbound or outbound, respectively. For taking into account the constraints due to other traffic on an airport surface, this solution is amended by a conflict detection and resolution task that attempts to reduce and possibly nullify the number of conflicts generated in the first phase. An example application on a simple Italian airport exemplifies how the algorithm can be applied to true-world applications. Emphasis is given on how to model an airport surface as a weighted and directed graph with non-negative weights, as required for the input to the algorithm.

  18. Radiation exposure of pediatric patients and physicians during cardiac catheterization and balloon pulmonary valvuloplasty

    International Nuclear Information System (INIS)

    Thermoluminescent dosimeters were applied to various areas of 61 pediatric patients and physicians to measure radiation doses during routine cardiac catheterization and during 4 cases of balloon pulmonary valvuloplasty. Radiation doses were measured during chest roentgenography, fluoroscopy and cineangiography. Average skin dose to the chest was 121 microGy during chest x-ray, 5,182 microGy during catheterization and 641 mGy during valvuloplasty. For the eyes, thyroid and gonads of the patients, the exposure during routine catheterization was equal to 0.4, 6 and 0.2 chest x-rays, respectively. Radiation dose of the operator was 3 microGy for the eyes and 6 miCroGy in the thyroid. About 56% of the operator's dose could be reduced by thyroid shields, and 80% by lead aprons. The assistant received only 1 microGy outside the thyroid shield. Therefore, the authors have concluded that the patients dose during routine catheterization is largely based on our experimental results, but the dose is acceptable based on the risk factor analysis. The skin dose to the right lateral chest of the patient during valvuloplasty is extremely high, perhaps as high as the equivalent of 1,000 chest x-rays. Besides the clinical benefits of valvuloplasty, the long-term radiation-related hazards to the patient should be carefully monitored

  19. How airlines decide the average size of airplanes in Brazilian market? Study of the determinants and projections for the next decade [paper in Portuguese

    Directory of Open Access Journals (Sweden)

    Thyago Silva Hermeto

    2012-01-01

    Full Text Available In Brazilian market, all airlines companies have a complex problem to solve, regarding the ideal profile for the aircraft fleet: Embraer`s aircraft profile (availability of seats 100 passengers aircraft or Boeing or Airbus profile (available above 140 seats? To answer this question is necessary to think about the following boundary conditions: (1 the organic growth of passangers at a rate of 11,8%/year (2003-2008, (2 physical limitations of the major airports - the ability of the passenger terminal, number of lanes, number of slots in the apron area, (3 the rate of completion of infrastructure works in this short of monitoring the speed of demand growth displayed until the present moment. To address this issue, this econometric study presents the evolution of the average size of aircraft used in Brazil. The middle step practiced by airlines is the variable that causes the choice for larger aircraft, with elasticity of 37,9%, in contrast, GDP growth leads to a choice of smaller aircraft, elasticity of –17,6%. The conclusion is that neutral scenario proved to be more consistent with market reality, there is an initial decrease of 6.5% over the average size of the aircraft in July 2010 and July 2020 shows an increase of 9.8%.

  20. Argon geochronology of Kilauea's early submarine history

    Science.gov (United States)

    Calvert, A.T.; Lanphere, M.A.

    2006-01-01

    Submarine alkalic and transitional basalts collected by submersible along Kilauea volcano's south flank represent early eruptive products from Earth's most active volcano. Strongly alkalic basalt fragments sampled from volcaniclastic deposits below the mid-slope Hilina Bench yield 40Ar/39Ar ages from 212 ?? 38 to 280 ?? 20 ka. These ages are similar to high-precision 234 ?? 9 and 239 ?? 10 ka phlogopite ages from nephelinite clasts in the same deposits. Above the mid-slope bench, two intact alkalic to transitional pillow lava sequences protrude through the younger sediment apron. Samples collected from a weakly alkalic basalt section yield 138 ?? 30 to 166 ?? 26 ka ages and others from a transitional basalt section yield 138 ?? 115 and 228 ?? 114 ka ages. The ages are incompatible with previous unspiked K-Ar studies from samples in deep drill holes along the east rift of Kilauea. The submarine birth of Kilauea volcano is estimated at <300 ka. If the weakly alkalic sequence we dated is representative of the volcano as a whole, the transition from alkalic to tholeiitic basalt compositions is dated at ??? 150 ka. ?? 2005 Elsevier B.V. All rights reserved.

  1. Radiation protection principles observance in Iranian dental schools

    International Nuclear Information System (INIS)

    In recent decades many guidelines has been conducted by radiation protection organizations about radiation protection in dentistry. This study aimed to evaluate the observance of these guidelines in educational clinics of all dental schools in Iran. Material and Methods: In this cross-sectional study a self-administered questionnaire, based on National Radiation Protection Board and European Commission guidelines, was conducted. The radiology departments of all dental school (18 schools) were surveyed in this study. The questionnaire was consisted of 3 sections including intraoral radiography, extra oral radiography and implementation of quality control programs. Results: In the case of the existence of radiation protection facilities (such as lead apron, thyroid shield and lead impacted walls) the use of high speed films and existence of automatic processor in dental schools, there was a proper condition. The main problem was related to lack of regular quality control and quality assurance programs. Digital radiography systems were employed in none of the schools and it was occasionally used for research purposes at some of them. Conclusions: This study has emphasized on the need for further consideration of radiation protection principles in dental schools, especially on the field of quality control and quality assurance programs.

  2. Radiation protection dosimetry in medicine - Report of the working group n.9 of the European radiation dosimetry group (EURADOS) - coordinated network for radiation dosimetry (CONRAD - contract EC N) fp6-12684

    International Nuclear Information System (INIS)

    This report present the results achieved within the frame of the work the WP 7 (Radiation Protection Dosimetry of Medical Staff) of the coordination action CONRAD (Coordinated Network for Radiation Dosimetry) funded through the 6. EU Framework Program. This action was coordinated by EURADOS (European Radiation Dosimetry Group). EURADOS is an organization founded in 1981 to advance the scientific understanding and the technical development of the dosimetry of ionising radiation in the fields of radiation protection, radiobiology, radiation therapy and medical diagnosis by promoting collaboration between European laboratories. WP7 coordinates and promotes European research for the assessment of occupational exposures to staff in therapeutic and diagnostic radiology workplaces. Research is coordinated through sub-groups covering three specific areas: 1. Extremity dosimetry in nuclear medicine and interventional radiology: this sub-group coordinates investigations in the specific fields of the hospitals and studies of doses to different parts of the hands, arms, legs and feet; 2. Practice of double dosimetry: this sub-group reviews and evaluates the different methods and algorithms for the use of dosemeters placed above and below lead aprons in large exposure during interventional radiology procedures, especially to determine effective doses to cardiologists during cardiac catheterization; and 3. Use of electronic personal dosemeters in interventional radiology: this sub-group coordinates investigations in laboratories and hospitals, and intercomparisons with passive dosemeters with the aim to enable the formulation of standards. (authors)

  3. Occupational doses during the injection of contrast media in paediatric CT procedures

    International Nuclear Information System (INIS)

    The administration of intravenous contrast media by hand or power injection in paediatric computed tomography (CT) procedures is carried out at King Faisal Specialist Hospital and Research Centre for chest, abdomen and torso diagnostic examinations. Some procedures require the CT unit to commence patient scanning during the injection of the last volume of the contrast medium. During the injection, even if the nurse is wearing a 0.5 mm lead equivalent protective apron, the head region and the hand are likely to receive high doses. This study was therefore made to assess the head and extremity doses to the nurses during CT procedures where typical exposure parameters of 200 to 220 mA s and 120 kVp were used. Thermoluminescence dosemeters were deployed for three consecutive months in two CT rooms. A total of 96 procedures were performed during this period and they were included in this study. Scattered radiation measurements were done at different locations where the nurse may be positioned. Results showed that the average dose to the head region and the hands per paediatric case were 50 μSv and 80 μSv respectively. This study investigated the factors that affect the dose and found them to be the length of stay inside the room, type of CT examination, exposure parameters and location of the nurse. (author)

  4. Radiation protective clothing

    International Nuclear Information System (INIS)

    The present invention concerns radiation protective clothings suitable for medical protective clothings, aprons, etc. A primary sheet comprises a lead-incorporated organic polymer layer having a less frictional layer on one side and a contamination-resistant layer on the other side. A secondary sheet comprises a lead-incorporated organic polymer layer having a less frictional layer on one side and a comfortable skin-feeling layer on the other side. The less frictional layers of the primary and the secondary layer are laminated so as to be in contact with each other. Then, they are formed so that the comfortable skin-feeling layer of the secondary sheet is on the inner side, in other words, on the side of a wearer, and the contamination-resistant layer of the primary sheet is on the outer side. With such a constitution, although it involves the lead-incorporated organic polymer sheets of a large weight, it is comfortable to wear because of excellent flexibility and causes less feeling of fatigue even during wearing for a long period of time. (I.N.)

  5. A survey on radiation exposure of primary operators from interventional X-ray procedures

    International Nuclear Information System (INIS)

    To understand the situation of radiation exposure to primary operators in the interventional X-ray procedures, a pilot survey was conducted for the 5 most frequently performed procedures in Shanghai in 2011. The distributions of entrance-surface air kerma (ESAK) were measured with thermoluminescent dosimeters (TLD) in 125 primary operators conducting the 5 procedures in 10 hospitals in Shanghai, and the equivalent doses (HT) for eye lens and extremity as well as the effective dose (E) were estimated. The results showed that the mean ESAKs were usually larger than 10 μGy for unshielded eye lens and extremity in each procedure, and the annual HT for unshielded eye lens exceeded 10 mSv in some procedures, such as the coronary angiography (CA) and angioplasty (PTCA). The mean annual effective doses were estimated to be 0.7–10.4 mSv among the 5 procedures, however, the values varied with different calculation algorithms. -- Highlights: ► It is the first and well designed survey in Shanghai, P. R. China. ► Under the apron, the exposure to left side and right side of chest are also different. ► The doses vary a lot with different calculating algorithms for some procedures. ► Further studies are needed for accurate measurement and assessment of the doses

  6. Radiation exposure during equine radiography

    International Nuclear Information System (INIS)

    All personnel present in the X-ray examination room during equine radiography were monitored using low energy direct reading ionization chambers (pockets dosimeters) worn outside the lead apron at neck level. The individuals' task and dosimeter readings were recorded after each examination. Average doses ranged from 0 to 6 mrad per study. The greatest exposures were associated with radiography of the shoulder and averaged less than 4 mrad. The individual extending the horse's limb was at greatest risk although the individual holding the horse's halter and the one making the X-ray exposure received similar exposures. A survey of the overhead tube assembly used for some of the X-ray examinations also was performed. Meter readings obtained indicated an asymetric dose distribution around the tube assembly, with the highest dose occurring on the side to which the exposure cord was attached. Although the exposures observed were within acceptable limits for occupational workers, we have altered our protocol and no longer radiograph the equine shoulder unless the horse is anesthetized. Continued use of the pocket dosimeters and maintenance of a case record of radiation exposure appears to make the technologists more aware of radiation hazards

  7. Radiological safety aspects of new FBTR Fuel Fabrication Facility at Radiological Laboratories, Trombay

    International Nuclear Information System (INIS)

    Mixed Uranium Plutonium Carbide, (U, Pu)C, in the form of pellets encapsulated in stainless steel tubes is the fuel for Fast Breeder Test Reactor (FBTR) at Kalpakkam. Due to stringent engineering safety with defense in depth approach potential internal hazard is minimized in the facility. However, external radiation hazard is dominant in the handling of this fuel in spite of several engineered safety features adopted in these facilities. To quantify such hazards, stage-wise evaluation of radiological safety parameters was carried out for the entire fabrication operation. The individual exposures are closely followed using Digital dosimeter (DRD), Thermo luminescence Dosimeter (TLD) etc. and by administrative control. Apart from this, routine work place monitoring and usage of specially designed lead impregnated aprons is made mandatory while working in the laboratories. The new Fuel Fabrication Lab at Radiometallurgy Division, Bhabha Atomic Research Centre has been designed with several safety engineering features. Estimation of occupational exposure for each operation is thoroughly evaluated with proper work planning for various batches of feed material. A comparison study was also carried out between old and new fabrication lab. In the new FBTR fabrication lab radiation exposure is controlled stringently even as the efficacy of the system has gone up several manifold. Maximum dose contribution is from final compaction operation because of the manual intervention. The present study in evaluating and addressing to safety aspects in each steps operation in the pellet fabrication process would result in controlling the occupational exposures ALARA

  8. Environmental Radiation Protection in Medical Institutions

    International Nuclear Information System (INIS)

    The study aimed to measure the levels of radiation protection for radiologists in medical institutions in three environmental categories (physical, administrative and social) and to establish a data base which can be used to increase awareness of environmental radiation protection in medical institutions within Korea. The study surveyed 10% of radiologists working in radiology departments in medical institutions which are supervised by the National Dose Registry overseen by the Korean Food and Drug Administration(KFDA). This study found that the level of environmental radiation protection was higher in the capital area and in larger hospitals. On the other hand, the study shows environmental radiation protection was lower in the Youngnam area and in clinics. Results from the questionnaires indicate the level of environmental radiation protection was higher when radiologists were given an individual dosimeter but lowest when the radiation protection apron quality test was conducted. Environmental radiation protection is an important factor for radiologists to conduct activities in a safe and protected environment. However, this study shows there are differences in the level of environmental radiation protection in medical institutions and location within Korea. In particular, the level of environmental radiation protection was lower in clinics, appropriate intervention strategies befitting these conditions are needed based on medical institution classification and location in order to improve the level of environmental protection

  9. Occupational dosimetry in real time. Benefits for interventional radiology

    International Nuclear Information System (INIS)

    Occupational dosimetry is still a challenge in fluoroscopy-guided procedures. Personal dosimeters are not regularly used by many professionals. Most of the dosimeters used are worn under the lead apron and it is difficult to estimate radiation doses to the unprotected organs and tissues. New electronic dosimeters make it possible to know staff doses and dose rates in real time, inside interventional laboratories. A system using solid-state detectors and equipped with a wireless connection (DoseAware distributed by Philips) that sends the scatter dose rate and cumulative scatter dose readings to a base station, inside the catheterization room, has been evaluated. The initial test was carried out over a period of 4 months in two laboratories (a cardiology one and a second one dedicated to general interventional procedures). In addition to the educational value of the dosimetry system, other benefits have been identified such as the detailed information on occupational dose rate during the procedures, the possibility of comparing occupational doses registered among different staff during the procedures, the capability of establishing correlations between occupational and patient doses, and correlations between staff doses and geometry and radiographic factors used during the procedures. From all this information, it is possible to derive criteria for optimization of occupational radiation protection.

  10. Influence of standing positions and beam projections on effective dose and eye lens dose of anaesthetists in interventional procedures

    International Nuclear Information System (INIS)

    More and more anaesthetists are getting involved in interventional radiology procedures and so it is important to know the radiation dose and to optimise protection for anaesthetists. In this study, based on Monte Carlo simulations and field measurements, both the whole-body doses and eye lens dose of anaesthetists were studied. The results showed that the radiation exposure to anaesthetists not only depends on their workload, but also largely varies with their standing positions and beam projections during interventional procedures. The simulation results showed that the effective dose to anaesthetists may vary with their standing positions and beam projections to more than a factor of 10, and the eye lens dose may vary with the standing positions and beam projections to more than a factor of 200. In general, a close position to the bed and the left lateral (LLAT) beam projection will bring a high exposure to anaesthetists. Good correlations between the eye lens dose and the doses at the neck, chest and waist over the apron were observed from the field measurements. The results indicate that adequate arrangements of anaesthesia device or other monitoring equipment in the fluoroscopy rooms are useful measures to reduce the radiation exposure to anaesthetists, and anaesthetists should be aware that they will receive the highest doses under left lateral beam projection. (authors)

  11. Exposure to and precautions for blood and body fluids among workers in the funeral home franchises of Fort Worth, Texas.

    Science.gov (United States)

    Nwanyanwu, O C; Tabasuri, T H; Harris, G R

    1989-08-01

    In 1982 the Centers for Disease Control published a set of recommendations and measures to protect persons working in health care settings or performing mortician services from possible exposure to the human immunodeficiency virus. This study of a number of funeral homes in the Fort Worth area was designed to determine the level of exposure of funeral home workers to blood and other body fluids and also to assess existing protective measures and practices in the industry. Workers in 22 funeral home franchises were surveyed with a predesigned questionnaire. Eighty-five responses from 20 of the 22 establishments were received. All 85 respondents admitted exposure of varying degrees to blood and body fluids. Sixty persons (70%) admitted heavy exposure, that is, frequent splashes. Analysis of the responses showed that 81 of 85 (95.3%) persons consistently wore gloves while performing tasks that might expose them to blood or other body fluids. Of the 60 persons who were heavily exposed, 43 wore long-sleeved gowns, 27 wore waterproof aprons, 17 surgical masks, and 15 goggles. The study further revealed that 52.9% (45/85) of the respondents had sustained accidental cuts or puncture wounds on the job. In light of these findings it is important to target educational efforts to persons in this industry to help them minimize their risks of infection with blood and body fluid borne infections. PMID:2549820

  12. Evaluation of radiation exposure in interventional radiology (IR) using active personal dosimeters (APD)

    International Nuclear Information System (INIS)

    Increased awareness of high personal dose exposure of medical staff in interventional radiology (IR) demands an assessment of radiation protection procedures. Mandatory dose monitoring systems do not allow to relate dose to specific actions of the staff as they just accumulate a total dose per month. Doses of head and limbs are expected to be high as those body parts which are not protected by the lead apron. We decided to use a measuring system by Unfors, RaySafe i2 which is built for real- time- dosimetry of scattered radiation in pulsed X-ray fields. An increased dose of the body side closer to the X-ray source (left body side) was detected. This is due to the position and the posture of the radiologist during intervention. Separating the phases of digital subtraction angiography (DSA) from those of fluoroscopy allowed not only to list the separate accumulated doses, but showed as well a big difference in dose rate. The measurements revealed the need of an improvement of common radiation protection, especially while DSA.

  13. Radiation protection dosimetry in medicine - Report of the working group n.9 of the European radiation dosimetry group (EURADOS) - coordinated network for radiation dosimetry (CONRAD - contract EC N) fp6-12684; Dosimetrie pour la radioprotection en milieu medical - rapport du groupe de travail n. 9 du European radiation dosimetry group (EURADOS) - coordinated netword for radiation dosimetry (CONRAD - contrat CE fp6-12684)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This report present the results achieved within the frame of the work the WP 7 (Radiation Protection Dosimetry of Medical Staff) of the coordination action CONRAD (Coordinated Network for Radiation Dosimetry) funded through the 6. EU Framework Program. This action was coordinated by EURADOS (European Radiation Dosimetry Group). EURADOS is an organization founded in 1981 to advance the scientific understanding and the technical development of the dosimetry of ionising radiation in the fields of radiation protection, radiobiology, radiation therapy and medical diagnosis by promoting collaboration between European laboratories. WP7 coordinates and promotes European research for the assessment of occupational exposures to staff in therapeutic and diagnostic radiology workplaces. Research is coordinated through sub-groups covering three specific areas: 1. Extremity dosimetry in nuclear medicine and interventional radiology: this sub-group coordinates investigations in the specific fields of the hospitals and studies of doses to different parts of the hands, arms, legs and feet; 2. Practice of double dosimetry: this sub-group reviews and evaluates the different methods and algorithms for the use of dosemeters placed above and below lead aprons in large exposure during interventional radiology procedures, especially to determine effective doses to cardiologists during cardiac catheterization; and 3. Use of electronic personal dosemeters in interventional radiology: this sub-group coordinates investigations in laboratories and hospitals, and intercomparisons with passive dosemeters with the aim to enable the formulation of standards. (authors)

  14. Model tests on influence of combined construction of sluices and pump stations on estuarine navigation%闸站合建枢纽对河口通航影响的模型试验

    Institute of Scientific and Technical Information of China (English)

    王法猛; 傅宗甫; 吕家才; 刘明明

    2012-01-01

    为了改善河口平面闸站合建枢纽水闸出流时容易在闸下河道内出现主流集中、偏流、回流,外河航道内横向流速大等问题,提出了在消力池下游海漫段设置八字形低坎的整流措施.基于平面闸站合建枢纽水力学模型试验,对有、无整流措施两种条件下闸下河道的水流流态、流速分布、特征断面流速不均匀系数以及航道内的最大横向流速进行了测试分析与比较.试验结果表明:闸下海漫段设置八字形整流低坎可以使外河入口断面流速不均匀系数从无整流措施的4.5 ~4.9降低到0.3 ~1.4,且使外河航道内的横向流速大大降低,模型试验实测的最大横向流速范围在0.30~0.50 m/s之间.外河入口断面流速不均匀系数和外河航道内横向流速的显著降低有助于河口闸站合建枢纽的通航安全,是一种简单而有效的工程措施.%In order to improve the discharge flows of a combined sluice-pump station project at estuary, that is, concentration, drift and reflux of the mainstream and increase of transverse velocity in outer river channel, a trapezoid type low ridge in the downstream apron of the stilling basin is proposed. Based on hydraulic model tests on the combined sluice-pump station project, the flow regime, velocity distribution, non-uniform coefficient of characteristic velocity and the maximum transverse velocity in the outer channel through the sluice gate with or without regulation measures are observed and compared. The test results show that the trapezoid type low ridge in the apron will make the non-uniform coefficient of the velocity at the entrance to the outer channel of 4. 5-4. 9 become 0. 3 - 1. 4, and the transverse velocity in the river greatly decreases. The observed range of the maximum transverse velocity is between 0. 3 m/s and 0. 5 m/s. The significant decrease of the non-uniform coefficient and the maximum transverse velocity may improve the effect of the

  15. Radiation exposure of the radiological staff caused by radiography of small mammals, reptiles and birds; Untersuchungen zur Strahlenexposition des radiologisch taetigen Personals bei der Radiographie von Heimtieren, Reptilien sowie Zier- und Wildvoegeln

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, Yvonne

    2015-05-27

    maximum measured doses were 11.4 μSv for the eye-lenses, 11.5 μSv for the thyroid, 5.67 μSv for the thoracic region under the lead apron, 3.47 μSv for the thoracic region above the lead apron, 1.86 μSv for the gonads, 182 μSv for the fingers and 2.05 μSv for the foot. The median of all dose values was 0.53 μSv. The analysis of the results showed that radiation exposure of staff during X-raying small mammals, reptiles and birds was very low. Dose values at the eye-lenses, thyroid region and the fingers were regularly measurable and were annotated. The most exposed body regions were the fingers, which were closest to the primary x-ray field during X-raying. All in all, the measured dose values were in the range of a few microsievert. There was no influence of dose-influencing-parameters on the dose. There was a slight, non-significant trend that heavier patients caused higher dose values because of more scattered radiation, and also a higher kV-number was correlated with an increase in dose rate. The comparison between measuring positions above and under the protection clothes showed that even the values measured above the protection clothes were low. Furthermore, the protective effect of protection clothes was pointed out. Therefore it is not necessary to optimize the radiation protection measures in the clinic. The results of the estimation of the annual radiation exposure of the radiological staff underlined that the exposure is well below the national dose limits for occupationally exposed persons. The conservative maximum effective dose amounted to less than 1 % of the civilizing radiation exposure of all citizens in Germany. Moreover the evaluation of the results concerning the anesthetic risk of the patients showed that routinely X-raying without any anesthesia is justifiable.

  16. Occupational exposure of medical staff: An overview

    International Nuclear Information System (INIS)

    higher. Often distinction is made between interventional cardiology and radiology. And there are also a number of procedures which are performed outside the radiology or cardiology department. The staff present in the fluoroscopy room should in principle always wear a lead apron. This reduces very much the whole body doses, but several parts of the body are not protected: hands, feet, head, sometimes thyroid (if no collar is used). The use of lead aprons introduces a problem of dose monitoring of the staff. The regulations differ from country to country whether to wear one or two dosemeters, where they should be worn, and how the results should be interpreted. Dental radiology: In almost every dental office or clinic, a diagnostic X-ray machine is available and frequently used. The number of X-ray devices used in dentistry is thus extremely large. Occupational exposure in dentistry is from scattered radiation from the patient and leakage from the tube head, although the latter should be insignificant with modem equipment. A majority of dental practitioners do not receive measurable doses, and indeed some regulatory authorities do not require routine. A recent trend is the introduction of dental CBCT. This is again mostly of concern for patient doses, but also staff doses can increase due to this. Nuclear medicine: Whereas the broad aim in diagnostic radiology is the imaging of anatomy, that in nuclear medicine is more the investigation of physiological processes. The use of radionuclide generators, particularly 99mTc generators, requires handling tens of gigabecquerels of radioactive material during the elution process. The magnitude of the exposures when performing clinical nuclear medicine procedures depends on the precautions taken, including the use of syringe shields when performing the injections. Personnel must be close to the patient when giving the injections and while positioning the patient and camera. Special care should go to the extremity doses in nuclear

  17. Radiation exposure of the radiological staff caused by radiography of small mammals, reptiles and birds

    International Nuclear Information System (INIS)

    maximum measured doses were 11.4 μSv for the eye-lenses, 11.5 μSv for the thyroid, 5.67 μSv for the thoracic region under the lead apron, 3.47 μSv for the thoracic region above the lead apron, 1.86 μSv for the gonads, 182 μSv for the fingers and 2.05 μSv for the foot. The median of all dose values was 0.53 μSv. The analysis of the results showed that radiation exposure of staff during X-raying small mammals, reptiles and birds was very low. Dose values at the eye-lenses, thyroid region and the fingers were regularly measurable and were annotated. The most exposed body regions were the fingers, which were closest to the primary x-ray field during X-raying. All in all, the measured dose values were in the range of a few microsievert. There was no influence of dose-influencing-parameters on the dose. There was a slight, non-significant trend that heavier patients caused higher dose values because of more scattered radiation, and also a higher kV-number was correlated with an increase in dose rate. The comparison between measuring positions above and under the protection clothes showed that even the values measured above the protection clothes were low. Furthermore, the protective effect of protection clothes was pointed out. Therefore it is not necessary to optimize the radiation protection measures in the clinic. The results of the estimation of the annual radiation exposure of the radiological staff underlined that the exposure is well below the national dose limits for occupationally exposed persons. The conservative maximum effective dose amounted to less than 1 % of the civilizing radiation exposure of all citizens in Germany. Moreover the evaluation of the results concerning the anesthetic risk of the patients showed that routinely X-raying without any anesthesia is justifiable.

  18. The Surface of Venus is Saturated With Ancient Impact Structures, and its Plains are Marine Sediments

    Science.gov (United States)

    Hamilton, W. B.

    2009-05-01

    Conventional interpretations of Venus are forced to fit dubious pre-Magellan conjectures that the planet is as active internally as Earth and preserves no ancient surface features. Plate tectonics obviously does not operate, so it is commonly assumed that the surface must record other endogenic processes, mostly unique to Venus. Imaginative systems of hundreds of tiny to huge rising and sinking plumes and diapirs are invoked. That much of the surface in fact is saturated with overlapping large circular depressions with the morphology of impact structures is obscured by postulating plume origins for selected structures and disregarding the rest. Typical structures are rimmed circular depressions, often multiring, with lobate debris aprons; central peaks are common. Marine-sedimentation features are overlooked because dogma deems the plains to be basalt flows despite their lack of source volcanoes and fissures. The unearthly close correlation between geoid and topography at long to moderate wavelengths requires, in conventional terms, dynamic maintenance of topography by up and down plumes of long-sustained precise shapes and buoyancy. A venusian upper mantle much stronger than that of Earth, because it is cooler or poorer in volatiles, is not considered. (The unearthly large so-called volcanoes and tessera plateaus often are related to rimmed circular depressions and likely are products of impact fluidization and melting.) Plains-saturating impact structures (mostly more obvious in altimetry than backscatter) with diameters of hundreds of km are superimposed as cookie-cutter bites, are variably smoothed and smeared by apparent submarine impact and erosion, and are differentially buried by sediments compacted into them. Marine- sedimentation evidence includes this compaction; long sinuous channels and distributaries with turbidite- channel characteristics and turbidite-like lobate flows (Jones and Pickering, JGSL 2003); radar-smooth surfaces and laminated aspect in

  19. Avaliação da exposição dos médicos à radiação em procedimentos hemodinâmicos intervencionistas Evaluation of radiation exposure to physicians during hemodynamic interventional procedures

    Directory of Open Access Journals (Sweden)

    Leonardo Peres da Silva

    2008-10-01

    Full Text Available OBJETIVO: Este trabalho avalia a distribuição de dose recebida por médicos envolvidos em procedimentos hemodinâmicos de angioplastia coronária e coronariografia. A influência de alguns fatores, como o modo de fluoroscopia pulsado ou contínuo e o local de acesso à veia e/ou artéria, foi investigada. MATERIAIS E MÉTODOS: Para esta avaliação foram feitas medições utilizando dosímetros termoluminescentes de LiF:Mg,Ti, posicionados em sete diferentes pontos do corpo dos profissionais: mãos, joelho, pescoço, testa e tórax, por dentro e por fora do avental de chumbo. A dose foi avaliada, por exame, nos médicos que executaram os procedimentos (30 de angioplastia e 60 de coronariografia. Os dosímetros termoluminescentes foram calibrados na grandeza operacional equivalente de dose pessoal, Hp(d, nas profundidades de 0,07, 3 e 10 mm. RESULTADOS: Os resultados mostram a importância do uso do protetor de tireóide e avental de chumbo para a redução da dose recebida pelos médicos. As doses dos profissionais que executaram procedimentos por via braquial usando modo contínuo de fluoroscopia foram mais altas do que os que executaram por via femoral e modo pulsado de fluoroscopia. CONCLUSÃO: Este estudo mostra a necessidade de medidas adicionais de proteção e a implementação de mecanismos de treinamento em proteção radiológica para os médicos que trabalham com cardiologia intervencionista.OBJECTIVE: The present study evaluates the dose distribution received by physicians involved in hemodynamic procedures of coronary angiography and coronariography. The influence of some factors such as pulsed or continuous fluoroscopy mode and vein and/or artery access site was investigated. MATERIALS AND METHODS: Measurements have been performed with LiF:Mg,Ti thermoluminescent dosimeters placed on seven different sites of the practitioners' bodies: hands, left knee, neck, forehead and chest, under and over the lead apron. Radiation doses for

  20. Integrative geomorphological mapping approach for reconstructing meso-scale alluvial fan palaeoenvironments at Alborz southern foothill, Damghan basin, Iran

    Science.gov (United States)

    Büdel, Christian; Majid Padashi, Seyed; Baumhauer, Roland

    2013-04-01

    Alluvial fans and aprons are common depositional features in general Iranian geomorphology. The countries major cities as well as settlements and surrounding area have often been developed and been built up on this Quaternary sediment covers. Hence they periodically face the effects of varying fluvial and slope-fluvial activity occurring as part of this geosystem. The Geological Survey of Iran therefore supports considerable efforts in Quaternary studies yielding to a selection of detailed mapped Quaternary landscapes. The studied geomorphologic structures which are settled up around an endorheic basin in Semnan Province represent a typical type of landform configuration in the area. A 12-km-transect was laid across this basin and range formation. It is oriented in north-south direction from the southern saltpan, called "Kavir-e-Haj Aligholi"/"Chah-e-Jam" ("Damghan Kavir"), across a vast sandy braided river plain, which is entering from the north east direction of the city of Shahroud. At its northern rim it covers alluvial sediment bodies, which are mainly constituted by broad alluvial aprons, fed by watersheds in Alborz Mountains and having their genetic origins in Mio-/Pliocene times. During this study a fully analytical mapping system was used for developing a geodatabase capable of integrating geomorphological analyses. Therefore the system must provide proper differentiation of form, material and process elements as well as geometric separation. Hence the German GMK25 system was set up and slightly modified to fit to the specific project demands. Due to its structure it offers most sophisticated standards and scale independent hierarchies, which fit very well to the software-determinated possibilities of advanced geodatabase applications. One of the main aspects of mapping Quaternary sediments and structures is to acquire a proper description and systematic correlation and categorization of the belonging mapping-objects. Therefore the team from GSI and

  1. Radiation exposure to examiners and patients during therapeutic ERCP: Dose optimisation and risk estimation

    International Nuclear Information System (INIS)

    Aim: This study intended to optimise the radiation dose during therapeutic ERCP, and to estimate the risk for examiners and patients, to compare the doses based on available data obtained by other researchers and reference levels recommended by international organizations, and to evaluate the technique applied in order to reduce patient and examiners doses. Materials and Methods: 153 patients were studied in two Gastroenterology Departments, (group A, 111; group B, 42). Thermoluminescent dosimeters (TLD) were used to measure the staff and patients entrance surface dose (ESD) at different body sites. Results: The mean ESD, exit and thyroid surface dose per procedure was estimated to be 68.75 mGy, 3.45 mGy and 0.67 mGy, respectively. The mean patient effective dose was 3.44 mSv, and the cancer risk per procedure was estimated to be 190 x10-6. The effective dose for the first, second and third examiner was 0.4 μSv, 0.2 μSv and 5.0 μSv, respectively. Conclusion: The patient dose can be optimized by the presence of two experienced examiners and reduction of radiographic images. The examiners should use a wrap around lead apron since the highest dose originating from the X-ray tube, is incident on their side and back. The current formulae, which exist, underestimate the effective dose to the examiners, when they are applied for ERCP procedures. For both patients and examiners, our results were up to 60% lower compared to the lowest values found in previous studies. (authors)

  2. Role of experience, leadership and individual protection in cath lab. A multicenter questionnaire and workshop on radiation safety

    Energy Technology Data Exchange (ETDEWEB)

    Kuon, E. [Klinik Fraenkische Schweiz, Ebermannstadt (Germany). Div. of Cardiology; Weitmann, K.; Hoffmann, W. [University Medicine, Greifswald (Germany). Inst. for Community Medicine; Doerr, M.; Hummel, A.; Busch, M.C.; Felix, S.B.; Empen, K. [University Medicine, Greifswald (Germany). Div. of Internal Medicine

    2015-10-15

    Radiation exposure in invasive cardiology remains considerable. We evaluated the acceptance of radiation protective devices and the role of operator experience, team leadership, and technical equipment in radiation safety efforts in the clinical routine. Cardiologists (115 from 27 centers) answered a questionnaire and documented radiation parameters for 10 coronary angiographies (CA), before and 3.1 months after a 90-min. mini-course in radiation-reducing techniques. Mini-course participants achieved significant median decreases in patient dose area products (DAP: from 26.6 to 13.0 Gy x cm{sup 2}), number of radiographic frames (- 29 %) and runs (- 18 %), radiographic DAP/frame (- 32 %), fluoroscopic DAP/s (- 39 %), and fluoroscopy time (- 16 %). Multilevel analysis revealed lower DAPs with decreasing body mass index (- 1.4 Gy x cm{sup 2} per kg/m2), age (- 1.2 Gy x cm{sup 2}/decade), female sex (- 5.9 Gy x cm{sup 2}), participation of the team leader (- 9.4 Gy x cm{sup 2}), the mini-course itself (- 16.1 Gy x cm{sup 2}), experience (- 0.7 Gy x cm{sup 2}/1000 CAs throughout the interventionalist's professional life), and use of older catheterization systems (- 6.6 Gy x cm{sup 2}). Lead protection included apron (100 %), glass sheet (95 %), lengthwise (94 %) and crosswise (69 %) undercouch sheet, collar (89 %), glasses (28 %), cover around the patients' thighs (19 %), foot switch shield (7 %), gloves (3 %), and cap (1 %). Radiation-protection devices are employed less than optimally in the clinical routine. Cardiologists with a great variety of interventional experience profited from our radiation safety workshop - to an even greater extent if the interventional team leader also participated.

  3. Morphological changes at Colima volcano caused the 2015 Hurricane Patricia investigated by repeated drone surveys and time lapse cameras

    Science.gov (United States)

    Walter, Thomas R.; Navarro, Carlos; Arambula, Raul; Salzer, Jackie; Reyes, Gabriel

    2016-04-01

    Colima is one of the most active volcanoes in Latin America, with frequent dome building eruptions and pyroclastic flow hazards. In July 2015 Colima had a new climax of eruptive activity, profoundly changing the summit morphology and redistributing volcanic ashes to the lower volcano apron. These unconsolidated ashes are prone to be mobilized by rainfall events, and therefore required close monitoring. A major hurricane then had landfall in western Mexico in October 2015, accumulating c. 450 mm of rainfall at a meteorological station at Nevado de Colima (3461 m) and immense lahar and ash deposit mobilization from Colima Volcano. Hurricane Patricia was the largest ever recorded category 5 storm, directly crossing the state of Colima. Due to the successful scientific advice and civil protection no human losses were directly associated to this lahar hazards. We have conducted drone overflight in profound valleys that directed the pyroclastic flows and lahars two days before and three days after the hurricane. Over 8,000 close range aerial photographs could be recorded, along with GPS locations of ground stations. Images were processed using the structure from motion methodology, and digital elevation models compared. Erosion locally exceeded 10 m vertically and caused significant landscape change. Mass mobilization unloaded the young pyroclastic deposits and led to significant underground heat loss and water boiling in the affected areas. We also firstly report the use of camera array set-ups along the same valley to monitor lahar deposition and erosion from different perspectives. Combining these photos using photogrammetric techniques allow time series of digital elevation change studies at the deepening erosional ravines, with large potential for future geomorphic monitoring. This study shows that photo monitoring is very useful for studying the link of volcano landscape evolution and hydrometerological extremes and for rapid assessment of indirect volcanic hazards.

  4. New glacoated area in Rodna mountains-Tarnița la Cruce cirque

    Directory of Open Access Journals (Sweden)

    Marcel MÎNDRESCU

    2008-03-01

    Full Text Available Even though we refer just to one former glacial site in the Rodna mountain area, this is important from several points of view, firstly, this one was missed by previous researchers because of its lateral position from the axis of glaciation, the main ridge of the Rodna Mountains. Secondly, the cirque, with its altitude and shape,completes a population of cirques less represented in the Eastern Carpathians, compared with the Alps of Transylvania. These are called alpine cirques in the world literature, but we prefer this term of ‘Carpathian’ to fit better with the geomorphologic reality of the Romanian Carpathians. These alpine cirques have small dimensions, with apron floors where there were cold glaciers (in the ablationand accumulation areas situated inside the cirque but short ones, which ended immediately after the floor, without being continued by glacier tongues. Nowadays, after the disappearance of Quaternary glaciers, these appear hanging on the high mountain ridges (being also valley-side cirques, far from the bottom of the valleys,and have a clean aspect. Finally, this mountainous site is important and interesting, at the same time, because it is a natural mountainous environment, untouched by pollution and human influence, and very sensitive to the environmental changes. It is a ‘fresh’ glaciated site which undergoes changes because of the ending of glaciation,so any change of the environment will be sensed by its ecosystem. Therefore, this area represents a potential site for scientific research to evaluate the impact of present changes in the environment.

  5. Evaluation of the enter surface dose, dose in organ and E effective dose, received by personnel and patients in studies of endoscopic retrograde cholangeopancreatography in the General Hospital of Mexico

    International Nuclear Information System (INIS)

    The ESD for patient and personal is measured: gastroenterologuist endoscopist G1, A1 Assistant and A2 instrumentist that carried out 22 independent therapeutic procedures of CPRE, in a fluoroscopy equipment Toshiba trademark with tube under the table, operated in automatic exposure mode, CAE to average tensions of 80 kVp. The measurement is carried out with film dosemeters of double emulsion Kodak Type 2 trademark, calibrated in terms of H* for the energy of the 137 Cs, first it is determined the films sensitivity like function of the optical density DO, and second the ESD for the effective energy of the radiation beam (50 keV), in three different points from the dosemeter (C, D and H). The films was placed for the personnel in: right hand, front (eye), thyroid and thorax (under D and out F of the lead apron); in the case of the patient three positions were used: thorax, hepatic region and pelvis. The mean values of the ESD and it standard deviation SD in mGy units are determined by: study, personnel, film position in doctor and patient, dosemeter measurement point. The calculated doses in organ are also determined for the patient in the thorax region, liverwort and pelvis its are agreement with the NRPB SR 262 report. Finally the HE and E for medical personnel and patients are estimated demonstrating that its are not exceeded the annual dose limits for the case of the OEP. In the case of the the OEP have for the D thorax an ESDmax = 0.04 mGy that one corresponds an HE = 0.02 and E = 0.01 mSv. (Author)

  6. SU-E-I-57: Estimating the Occupational Eye Lens Dose in Interventional Radiology Using Active Personal Dosimeters Worn On the Chest

    Energy Technology Data Exchange (ETDEWEB)

    Omar, A; Marteinsdottir, M; Kadesjo, N; Fransson, A [Dept. of Medical Physics, Karolinska University Hospital, Stockholm (Sweden)

    2015-06-15

    Purpose: To provide a general formalism for determination of occupational eye lens dose based on the response of an active personal dosimeter (APD) worn at chest level above the radiation protection apron. Methods: The formalism consists of three factors: (1) APD conversion factor converting the reading at chest level (APDchest) to the corresponding personal dose equivalent at eye level, (2) Dose conversion factor transferring the measured dose quantity, Hp(10), into a dose quantity relevant for the eye lens dose, (3) Correction factor accounting for differences in exposure of the eye(s) compared to the exposure at chest level (e.g., due to protective lead glasses).The different factors were investigated and evaluated based on phantom and clinical measurements performed in an x-ray angiography suite for interventional cardiology. Results: The eye lens dose can be conservatively estimated by assigning an appropriate numerical value to each factor entering the formalism that in most circumstances overestimates the dose. Doing so, the eye lens dose to the primary operator and assisting staff was estimated in this work as D-eye,primary = 2.0 APDchest and D-eye,assisting = 1.0 APDchest, respectively.The annual eye lens dose to three nurses and one cardiologist was estimated to be 2, 2, 2, and 13 mSv (Hp(0.07)), respectively, using a TLD dosimeter worn at eye level. In comparison, using the formalism and APDchest measurements, the respective doses were 2, 2, 2, and 16 mSv (Hp(3)). Conclusion: The formalism outlined in this work can be used to estimate the occupational eye lens dose from the response of an APD worn on the chest. The formalism is general and could be applied also to other types of dosimeters. However, the numerical value of the different factors may differ from those obtained with the APD’s used in this work due to differences in dosimeter properties.

  7. Mesozoic architecture of a tract of the European-Iberian continental margin: Insights from preserved submarine palaeotopography in the Longobucco Basin (Calabria, Southern Italy)

    Science.gov (United States)

    Santantonio, Massimo; Fabbi, Simone; Aldega, Luca

    2016-01-01

    The sedimentary successions exposed in northeast Calabria document the Jurassic-Early Cretaceous tectonic-sedimentary evolution of a former segment of the European-Iberian continental margin. They are juxtaposed today to units representing the deformation of the African and Adriatic plates margins as a product of Apenninic crustal shortening. A complex pattern of unconformities reveals a multi-stage tectonic evolution during the Early Jurassic, which affected the facies and geometries of siliciclastic and carbonate successions deposited in syn- and post-rift environments ranging from fluvial to deep marine. Late Sinemurian/Early Pliensbachian normal faulting resulted in exposure of the Hercynian basement at the sea-floor, which was onlapped by marine basin-fill units. Shallow-water carbonate aprons and reefs developed in response to the production of new accommodation space, fringing the newborn islands which represent structural highs made of Paleozoic crystalline and metamorphic rock. Their drowning and fragmentation in the Toarcian led to the development of thin caps of Rosso Ammonitico facies. Coeval to these deposits, a thick (> 1 km) hemipelagic/siliciclastic succession was sedimented in neighboring hanging wall basins, which would ultimately merge with the structural high successions. Footwall blocks of the Early Jurassic rift, made of Paleozoic basement and basin-margin border faults with their onlapping basin-fill formations, are found today at the hanging wall of Miocene thrusts, overlying younger (Middle/Late Jurassic to Late Paleogene) folded basinal sediments. This paper makes use of selected case examples to describe the richly diverse set of features, ranging from paleontology to sedimentology, to structural geology, which are associated with the field identification of basin-margin unconformities. Our data provide key constraints for restoring the pre-orogenic architecture of a continental margin facing a branch of the Liguria-Piedmont ocean in the

  8. Obesidad mórbida: caso excepcional de reconstrucción de pared abdominal Morbid obesity: an exceptional patient. Apronectomy and new abdominal wall reconstruction

    Directory of Open Access Journals (Sweden)

    F.J. Gabilondo Zubizarreta

    2006-09-01

    Full Text Available Presentamos una nueva técnica para la reconstrucción de la pared abdominal, con material sintético en una paciente que padeciendo un cuadro de obesidad mórbida sin cirugía ni traumatismo previo, sufre una diástasis de músculos rectos de su pared abdominal por la que se produce una evisceración intestinal que al alojarse en el faldón abdominal y añadirse un proceso de acumulación de líquidos en el intersticio semejante al linfedema, supuso como tratamiento una resección superior a los 60 Kg. entre sólidos y líquidos y una estrategia y técnica nuevas de reconstrucción del defecto de la pared abdominal.The aim of this work is to show a new technique for reconstruction of the abdominal wall with synthetic matherial in a patient with morbid obesity. The disease has no relation with antecedents of previous surgery or trauma and is asociated with a dyasthasis of the rectus abdomini muscles which has conditionated a intestinal evisceration.This evisceration is accommodated in the abdominal apron and is associated with a great accumulation of fluid (liquid in the interstitium, which seems a linphedema. Taking account the combination of liquid and soft tissues the resection is larger than 60 Kg. and this has forced us to develop new strategies for the menagement of the patient and techniques for the reconstruction of the abdominal wall defect.

  9. The rivers of civilization

    Science.gov (United States)

    Macklin, Mark G.; Lewin, John

    2015-04-01

    The hydromorphic regimes that underpinned Old World river-based civilizations are reviewed in light of recent research. Notable Holocene climatic changes varied from region to region, whilst the dynamics of floodplain environments were equally diverse, with river channel changes significantly affecting human settlement. There were longer-term trends in Holocene hydroclimate and multi-centennial length 'flood-rich' and 'flood-poor' episodes. These impacted on five identified flooding and settlement scenarios: (i) alluvial fans and aprons; (ii) laterally mobile rivers; (iii) rivers with well-developed levees and flood basins; (iv) river systems characterised by avulsions and floodouts; and (v) large river-fed wetlands. This gave a range of changes that were either more or less regular or incremental from year-to-year (and thus potentially manageable) or catastrophic. The latter might be sudden during a flood event or a few seasons (acute), or over longer periods extending over many decades or even centuries (chronic). The geomorphic and environmental impacts of these events on riparian societies were very often irreversible. Contrasts are made between allogenic and autogenic mechanism for imposing environmental stress on riverine communities and a distinction is made between channel avulsion and contraction responses. Floods, droughts and river channel changes can precondition as well as trigger environmental crises and societal collapse. The Nile system currently offers the best set of independently dated Holocene fluvial and archaeological records, and the contrasted effects of changing hydromorphological regimes on floodwater farming are examined. The persistence of civilizations depended essentially on the societies that maintained them, but they were also understandably resilient in some environments (Pharaonic Egypt in the Egyptian Nile), appear to have had more limited windows of opportunity in others (the Kerma Kingdom in the Nubian Nile), or required

  10. Uranium mineralization in fluorine-enriched volcanic rocks

    International Nuclear Information System (INIS)

    Several uranium and other lithophile element deposits are located within or adjacent to small middle to late Cenozoic, fluorine-rich rhyolitic dome complexes. Examples studied include Spor Mountain, Utah (Be-U-F), the Honeycomb Hills, Utah (Be-U), the Wah Wah Mountains, Utah (U-F), and the Black Range-Sierra Cuchillo, New Mexico (Sn-Be-W-F). The formation of these and similar deposits begins with the emplacement of a rhyolitic magma, enriched in lithophile metals and complexing fluorine, that rises to a shallow crustal level, where its roof zone may become further enriched in volatiles and the ore elements. During initial explosive volcanic activity, aprons of lithicrich tuffs are erupted around the vents. These early pyroclastic deposits commonly host the mineralization, due to their initial enrichment in the lithophile elements, their permeability, and the reactivity of their foreign lithic inclusions (particularly carbonate rocks). The pyroclastics are capped and preserved by thick topaz rhyolite domes and flows that can serve as a source of heat and of additional quantities of ore elements. Devitrification, vapor-phase crystallization, or fumarolic alteration may free the ore elements from the glassy matrix and place them in a form readily leached by percolating meteoric waters. Heat from the rhyolitic sheets drives such waters through the system, generally into and up the vents and out through the early tuffs. Secondary alteration zones (K-feldspar, sericite, silica, clays, fluorite, carbonate, and zeolites) and economic mineral concentrations may form in response to this low temperature (less than 200 C) circulation. After cooling, meteoric water continues to migrate through the system, modifying the distribution and concentration of the ore elements

  11. The stratigraphy of cretaceous mudstones in the eastern Fuegian Andes: new data from body and trace fossils

    Directory of Open Access Journals (Sweden)

    Eduardo B. Olivero

    2009-04-01

    Full Text Available The stratigraphy of Cretaceous marine mudstones in the Fuegian Andes, roughly equivalent to Charles Darwin's clay-slate formation, remains a still unsolved problem. Previous records of Albian, Turonian-Coniacian, and Santonian-Campanian bivalves are combined with new findings of the Late Albian inoceramid Inoceramus anglicus Woods, and the Maastrichtian ammonites Diplomoceras sp., Anagaudryceras sp., Maorites densicostatus (Kilian and Reboul, Maorites sp., and Pachydiscus (Neodesmoceras sp. to further constrain the Cretaceous stratigraphy of the eastern Fuegian Andes. In addition, new records of distinctive trace fossils and ichnofabric are meaningful for stratigraphic division and delineation of paleoenvironmental settings in these Cretaceous mudstones. The Lower Cretaceous ichnoassemblage of Chondrites targioni (Brongniart and Zoophycos isp. is consistent with the inferred slope-volcaniclastic apron settings of the Yahgan Formation; Nereites missouriensis (Weller reflects distal basin plain depositional settings for the Beauvoir Formation. In the Upper Cretaceous, the "Estratos de Buen Suceso" record the earliest extensively bioturbated horizons, reflecting prolonged well-oxygenated bottom conditions. In the Bahía Thetis Formation, organic-rich, channel margin or distal basin slaty mudstones record the last occurrence of inoceramid bivalves in the Austral Basin; the generalized absence of trace fossils is consistent with dysoxic bottom conditions. The thoroughly bioturbated Policarpo Formation, records a marked change in paleoceanographic conditions. The strong contrast in the intensity of bioturbation between the Upper Campanian-Maastrichtian Bahía Thetis Formation, almost devoid of trace fossils, and the highly bioturbated Maastrichtian-Danian Policarpo Formation reflects a change from dysoxic-anoxic to well ventilated conditions, probably associated with a cooling trend of bottom waters in the austral deep oceans.

  12. Uranium mineralization in fluorine-enriched volcanic rocks

    Energy Technology Data Exchange (ETDEWEB)

    Burt, D.M.; Sheridan, M.F.; Bikun, J.; Christiansen, E.; Correa, B.; Murphy, B.; Self, S.

    1980-09-01

    Several uranium and other lithophile element deposits are located within or adjacent to small middle to late Cenozoic, fluorine-rich rhyolitic dome complexes. Examples studied include Spor Mountain, Utah (Be-U-F), the Honeycomb Hills, Utah (Be-U), the Wah Wah Mountains, Utah (U-F), and the Black Range-Sierra Cuchillo, New Mexico (Sn-Be-W-F). The formation of these and similar deposits begins with the emplacement of a rhyolitic magma, enriched in lithophile metals and complexing fluorine, that rises to a shallow crustal level, where its roof zone may become further enriched in volatiles and the ore elements. During initial explosive volcanic activity, aprons of lithicrich tuffs are erupted around the vents. These early pyroclastic deposits commonly host the mineralization, due to their initial enrichment in the lithophile elements, their permeability, and the reactivity of their foreign lithic inclusions (particularly carbonate rocks). The pyroclastics are capped and preserved by thick topaz rhyolite domes and flows that can serve as a source of heat and of additional quantities of ore elements. Devitrification, vapor-phase crystallization, or fumarolic alteration may free the ore elements from the glassy matrix and place them in a form readily leached by percolating meteoric waters. Heat from the rhyolitic sheets drives such waters through the system, generally into and up the vents and out through the early tuffs. Secondary alteration zones (K-feldspar, sericite, silica, clays, fluorite, carbonate, and zeolites) and economic mineral concentrations may form in response to this low temperature (less than 200 C) circulation. After cooling, meteoric water continues to migrate through the system, modifying the distribution and concentration of the ore elements (especially uranium).

  13. Long-term monitoring of martian gully formation and evolution with MRO/HiRISE

    Science.gov (United States)

    Dundas, Colin M.; Diniega, Serina; McEwen, Alfred S.

    2015-05-01

    Gully landforms are commonly taken as evidence for surface liquid water in the recent geological history of Mars. Repeat observations with the High Resolution Imaging Science Experiment (HiRISE) instrument on the Mars Reconnaissance Orbiter demonstrate widespread activity in gullies in the southern hemisphere, particularly in those with the freshest morphologies. This activity includes substantial channel incision and large-scale mass movements, and constitutes ongoing gully formation rather than degradation of older landforms. New apron deposits that are bright, dark and neutrally toned have all been observed. The timing of gully activity is seasonally controlled and occurs during the period when seasonal frost is present and defrosting. These observations support a model in which currently active gully formation is driven mainly by seasonal CO2 frost. Gullies in the northern hemisphere are far less active than those in the south. This may be due to the current timing of perihelion near the northern winter solstice. Integrated over time, activity like that observed within the past few years appears capable of forming all of the martian gully landforms on timescales of millions of years. Additionally, the current style and rate of activity is able to erase meter- to decameter-scale surface features that might have been uniquely produced by other processes during the last obliquity high ∼0.4 Ma. Although it is impossible to rule out a past role for water in the formation of martian gullies, a model in which gullies form only through currently active processes with little or no liquid water is consistent with our observations.

  14. Morphology and processes in Lake Tahoe (California-Nevada)

    Science.gov (United States)

    Gardner, J.V.; Mayer, L.A.; Hughs, Clarke J.E.

    2000-01-01

    Lake Tahoe was surveyed using a state-of-the-art, high-resolution, multibeam mapping system to provide an accurate base map for the myriad of ongoing environmental studies in and around the lake. The newly defined basin morphology shows steep basin margins on the northern, eastern, and western sides and a gentle margin on the southern side. Two large, flat plateaus several kilometers wide extend from the shore to about 40 m water depth in the northwestern sections of the basin. A series of ridges in the west and north are presumed traces of faults, some of which border the lake basin and some of which traverse across the northern section of the lake and converge in McKinney Bay. McKinney Bay is a large reentrant in the western margin that was created by a failure of the western margin that occurred about 300 ka. The failure generated a major debris avalanche that carried large blocks, some more than 1000 m long and 80 m high, accross the basin. Apparently, the debris avalanche was deflected by the eastern margin of the basin and flowed to the north and south. Small debris flows and slides have continued to occur in this area. Small debris aprons along the northern, western, and eastern margins, some apparently the remnants of collapsed terminal moraines formed in the basin from the 160 ka Tahoe Glaciation, which reached the edge of the basin. Eroded plateaus and ridges occur on a glacial outwash plain that covers the gentle southern margin. The plateaus and ridges are inferred to be remnants of another large terminal moraine of the Tahoe Glaciation.

  15. Test and optimization of two routine dosemeters for the dose quantity Hp(3)

    International Nuclear Information System (INIS)

    The individual monitoring service Seibersdorf uses two different passive dosemeter types based on thermo luminescence (TL) detectors for monitoring occupationally exposed persons in Austria. Whole body personal dosemeters for the personal dose equivalent quantities Hp(10) and Hp(0.07) worn on the trunk and dosemeters for the extremities for Hp(0.07) worn on a finger or wrist. Both routine dosemeters were calibrated and tested in terms of the personal dose equivalent Hp(3) assuming that the whole body dosemeter is worn on the chest (without or above a lead apron) and the modified ring/wrist dosemeter using a special strap worn on the forehead near the eyes (head band dosemeter). The test results show that it is possible to measure the dose quantity Hp(3) with these dosemeters that were originally not designed for this dose quantity. Only changes in the dose calculation algorithm and in the choice of the reference radiation quality were necessary to fulfil the requirements given in international standards for passive dosemeters in a wide energy (20 keV–1.3 MeV) and angular range (0°–60°). - Highlights: • Whole body dosemeter for Hp(10) and Hp(0.07) can also be used for Hp(3). • The dose algorithm for whole body dosemeter can be changed for Hp(3). • Extremity dosemeter for Hp(0.07) can also be used for Hp(3) on the forehead. • The reference energy has to be changed for Hp(3)

  16. Evaluation of Prerequisite Programs Implementation and Hygiene Practices at Social Food Services through Audits and Microbiological Surveillance.

    Science.gov (United States)

    Garayoa, Roncesvalles; Yánez, Nathaly; Díez-Leturia, María; Bes-Rastrollo, Maira; Vitas, Ana Isabel

    2016-04-01

    Prerequisite programs are considered the most efficient tool for a successful implementation of self-control systems to ensure food safety. The main objective of this study was to evaluate the implementation of these programs in 15 catering services located in Navarra and the Basque Country (regions in northern Spain), through on-site audits and microbiological analyses. The implementation of the prerequisite program was incomplete in 60% of the sample. The unobserved temperature control during both the storage and preparation of meals in 20% of the kitchens reveals misunderstanding in the importance of checking these critical control points. A high level of food safety and hygiene (absence of pathogens) was observed in the analyzed meals, while 27.8% of the tested surfaces exceeded the established limit for total mesophilic aerobic microorganisms (≤100 CFU/25 cm²). The group of hand-contact surfaces (oven door handles and aprons) showed the highest level of total mesophilic aerobic microorganisms and Enterobacteriaceae, and the differences observed with respect to the food-contact surfaces (work and distribution utensils) were statistically significant (P Staphylococcus spp we identified 43 CFU/cm(2) on average compared with 4 CFU/cm(2) (P < 0.001) for those not wearing and wearing gloves, respectively). For a proper implementation of the prerequisites, it is necessary to focus on attaining a higher level of supervision of activities and better hygiene training for the food handlers, through specific activities such as informal meetings and theoretical-practical sessions adapted to the characteristics of each establishment. PMID:26953631

  17. Occupational exposure of apprentices in radiology in the field of professional training

    International Nuclear Information System (INIS)

    The good economic moment of our country has been providing an increase of courses in technical and technological area mainly in the field of radiology, which has raised the number of apprentices in the field of stage in clinics and hospitals. However, the shortage of placements and the fact that many of these students are workers, has forced the institutions of technical education to seek alternatives for the students to meet the workload of the stage in a time as short as possible. For this reason, often the students are obliged to comply with up to 10 hours of internship in a single day, in companies that often are not in accordance with the standards of radiological protection. What has worried the authorities of Goiania, because they believe that this exposure can raise the dose received. It is known that every person who works with X-ray diagnostics should use, during their work day and while stay in controlled area, individual dosimeter reading indirect, changed monthly. However, in practice these apprentices do not use the meter for monitoring of doses in probationary period. In This way, we measure the doses received us trainees using monitors TLDs in the thoracic region with and without plumbiferous apron on stage with total workload of 150 hours, performed daily from Monday to Friday for 6 hours per day during 5 weeks and performed to Saturday and Sunday for 10 hours daily in 7.5 weekends, with X-ray equipment conventional. The results reveal that in none of the cases the dose reached the value of 0.2 mSv, which is the minimum limit of reading dosimeter. We conclude then that the stages of weekends, taken the preventive measures of radiological protection are safe and can be performed without any prejudice with regard to the dose received, when compared to those of lower daily hourly load. (Author)

  18. Ebola virus disease surveillance and response preparedness in northern Ghana

    Directory of Open Access Journals (Sweden)

    Martin N. Adokiya

    2016-05-01

    Full Text Available Background: The recent Ebola virus disease (EVD outbreak has been described as unprecedented in terms of morbidity, mortality, and geographical extension. It also revealed many weaknesses and inadequacies for disease surveillance and response systems in Africa due to underqualified staff, cultural beliefs, and lack of trust for the formal health care sector. In 2014, Ghana had high risk of importation of EVD cases. Objective: The objective of this study was to assess the EVD surveillance and response system in northern Ghana. Design: This was an observational study conducted among 47 health workers (district directors, medical, disease control, and laboratory officers in all 13 districts of the Upper East Region representing public, mission, and private health services. A semi-structured questionnaire with focus on core and support functions (e.g. detection, confirmation was administered to the informants. Their responses were recorded according to specific themes. In addition, 34 weekly Integrated Disease Surveillance and Response reports (August 2014 to March 2015 were collated from each district. Results: In 2014 and 2015, a total of 10 suspected Ebola cases were clinically diagnosed from four districts. Out of the suspected cases, eight died and the cause of death was unexplained. All the 10 suspected cases were reported, none was confirmed. The informants had knowledge on EVD surveillance and data reporting. However, there were gaps such as delayed reporting, low quality protective equipment (e.g. gloves, aprons, inadequate staff, and lack of laboratory capacity. The majority (38/47 of the respondents were not satisfied with EVD surveillance system and response preparedness due to lack of infrared thermometers, ineffective screening, and lack of isolation centres. Conclusion: EVD surveillance and response preparedness is insufficient and the epidemic is a wake-up call for early detection and response preparedness. Ebola surveillance remains

  19. SU-E-P-46: Clinical Acceptance Testing and Implementation of a Portable CT Unit

    International Nuclear Information System (INIS)

    Purpose: Planning for the first installation in New England of a new portable CT unit to be used in the Operating Room required the integration of many departments including Surgery, Neurosurgery, Information Services, Clinical Engineering, Radiology and Medical Physics/Radiation Safety. Acceptance testing and the quality assurance procedures were designed to optimize image quality and patient and personnel radiation exposure. Methods: The vendor’s protocols were tested using the CT Dosimetry phantoms. The system displayed the CTDIw instead of the CTDIvol while testing the unit. Radiation exposure was compared to existing CT scanners from installed CT units throughout the facility. Brainlab measures all 4 periphery slots on the CT Dosimetry phantom. The ACR measures only the superior slot for the periphery measurement. A comprehensive radiation survey was also performed for several locations. Results: The CTDIvol measurements were comparable for the following studies: brain, C-Spine, and sinuses. However, the mobile CT measurements were slightly higher than other CT units but within acceptable tolerance if measured using the ACR method.Based on scatter measurements, it was determined if any personnel were to stay in the OR Suite during image acquisition that the appropriate lead apron and thyroid shields had to be worn.In addition, to reduce unnecessary scatter, there were two mobile 6 foot wide shields (1/16″ lead equivalent) available to protect personnel in the room and adjacent areas. Conclusion: Intraoperative CT provides the physician new opportunities for evaluation of the progression of surgical resections and device placement at the cost of increasing the amount of trained personnel required to perform this procedure. It also brings with it challenges to keep the radiation exposure to the patients and staff within reasonable limits

  20. SU-E-P-20: Personnel Lead Apparel Integrity Inspection: Where We Are and What We Need?

    International Nuclear Information System (INIS)

    Purpose: In recent years, tremendous efforts have been devoted to radiation dose reduction, especially for patients who are directly exposed to primary radiation or receive radiopharmaceuticals. Limited efforts have been focused on those personnel who are exposed to secondary radiation while fulfilling their work responsibilities associated with diagnostic imaging and image-guided interventions. Occupational exposure is compounded in daily practice and can lead to a significant radiation dose over time. Personnel lead apparel is a well-accepted engineering control to protect healthcare workers when radiation is inevitable. The question is, do we have a nationally established program to protect personnel? This study is to investigate the lead apparel inspection programs among the USA. Methods: A series of surveys of state regulations, the University Health System Consortium, and federal regulations and regulations determined by accrediting bodies were conducted. The surveys were used to determine the current status of lead apparel programs regarding integrity inspections. Based on the survey results, a thorough program was proposed accordingly. Results: Of 50 states, seventeen states and Washington D.C. require lead apparel integrity inspections within their state regulations. Eleven of these states specify that the inspection is required on an annual basis. Two of these states require lead apron integrity checks to be performed semi-annually. Eleven out of the two hundred academic medical centers surveyed responded. The results show that the method (visually vs. fluoroscopy) used to conduct lead apparel integrity checks differ greatly amongst healthcare organizations. The FDA, EPA, CRCPD and NCRP require lead apparel integrity checks. However, the level of policies is different. A standard program is not well established and clearly there is a lack of standardization. Conclusion: A program led by legislative (state or federal government) and with specific frequency

  1. Protection Against X-ray Treatment in Intervention Cardiology

    International Nuclear Information System (INIS)

    The aim of this paper is to show basic propositions on protection against ionizing radiation in intervention cardiology. X-ray treatment should also be subjected to all radiological standards and principles of protection against radiation as well as all other radiological examinations. A cardiologist takes over the role of a radiologist after successfully completing additional education. The measures for reducing radiation include professional team, X-ray machines, a diagnostic room and, first of all, a patients body. A long-life diascopy is replaced by aimed photos. Concerning the X-ray machines, filtration, limiting of the bundle of rays and usage of reinforced foils are the important parts. Protection of thyroid gland, eye lenses, ovaries or spermaries and haematic organs must be ensured by safety measures. People who work with x-ray machines must have protective means in working order and personal dosimeters. Protective power of aprons, gloves and glasses must be at least 0.25 mm thick concerning lead. A medical check-up before working with radiation includes a general medical check-up with a working anamnesis and an ophtalmological, gynoecological, dermatological check-up and a psycho test as well as a haematologic analysis, an analysis of chromosome aberration and an urinanalysis. A legal and a physical person who has been appointed to work with the sources of ionizing radiation is obliged to appoint a person responsible for protection against ionizing radiation. The danger which accompanies exposure to radiation cannot be completely eliminated. However, the risk must be limited and reduced by means of administrative, organizational and technological measures. (author)

  2. Assessment of exposure to the external radiation in the Haemodynamic procedure room at the University Hospital of Uruguay

    International Nuclear Information System (INIS)

    Assessment of exposure to the external radiation in the Haemodynamic procedure room at the University Hospital of Uruguay. Workers involved in cardiac procedures using fluoroscopy with X ray are exposed to high levels of ionizing radiation, mainly secondary radiation. The way to protect these workers is to have radiological protection rules and dosage limitation. In order to control the environmental conditions under which these people work, the personal is used. The objective is to keep 'the minimum expositions as it is reasonably possible' (ALARA statement) to minimize the doses and the associated risks. This research evaluated different effective doses of the workers that use a X-ray equipment with fluoroscopy and film (PickerR) using personal measuring radiation level. This equipment belongs to the Services of the University Hospital. Levels of radiation in the positions the operators work during the procedures were also estimated measuring the specific radiation using environmental dosimeters dose during 25 procedures. Both, personal and environmental measuring radiation level are KodakR type 2 and were calibrated in the secondary lab of calibration of Ezeiza, Argentina. The operators used lead apron, thyroid and frequently eyes protection. Two measuring radiation level are used, one under and on above of the protection as it is recommended by IRPA. The registered accumulative annual doses and effective doses estimated for the different operators. The maximum registered dose was 3.79 mSv and the correspondence effective dose was 0.18 mSv. The results of the environmental measures for the 25 studies (5000 seconds of emission effective).The maximum registered dose was 36 mSv in the place occupied by the doctor operator. According to the personal measuring radiation level results the radio sanitary conditions are adequate, however the radiation levels measured close to the X ray-tube were high. It would be necessary to take more cares during the procedures, for

  3. Fine-Grained Turbidites: Facies, Attributes and Process Implications

    Science.gov (United States)

    Stow, Dorrik; Omoniyi, Bayonle

    2016-04-01

    Within turbidite systems, fine-grained sediments are still the poor relation and sport several contrasting facies models linked to process of deposition. These are volumetrically the dominant facies in deepwater and, from a resource perspective, they form important marginal and tight reservoirs, and have great potential for unconventional shale gas, source rocks and seals. They are also significant hosts of metals and rare earth elements. Based on a large number of studies of modern, ancient and subsurface systems, including 1000s of metres of section logging, we define the principal genetic elements of fine-grained deepwater facies, present a new synthesis of facies models and their sedimentary attributes. The principal architectural elements include: non-channelised slope-aprons, channel-fill, channel levee and overbank, turbidite lobes, mass-transport deposits, contourite drifts, basin sheets and drapes. These comprise a variable intercalation of fine-grained facies - thin-bedded and very thin-bedded turbidites, contourites, hemipelagites and pelagites - and associated coarse-grained facies. Characteristic attributes used to discriminate between these different elements are: facies and facies associations; sand-shale ratio, sand and shale geometry and dimensions, sand connectivity; sediment texture and small-scale sedimentary structures; sediment fabric and microfabric; and small-scale vertical sequences of bed thickness. To some extent, we can relate facies and attribute characteristics to different depositional environments. We identify four distinct facies models: (a) silt-laminated mud turbidites, (b) siliciclastic mud turbidites, (c) carbonate mud turbidites, (d) disorganized silty-mud turbidites, and (e) hemiturbidites. Within the grainsize-velocity matrix turbidite plot, these all fall within the region of mean size material. Hemiturbidites are the result of long-distance transport and an upward buoyancy mechanism during deposition.

  4. Salt Weathering on Mars

    Science.gov (United States)

    Jagoutz, E.

    2006-12-01

    Large well rounded boulders and angular rock fragments characterizes the Martian landscape as seen on the recent excellent quality photos. Analyzing the different rock-shapes indicates a time sequence of emplacement, fragmentation and transport of different rocks on Mars, which might give interesting insight into transport and weathering processes. Larger commonly well rounded boulders were emplaced onto gravel plains. After emplacement, these rocks were fragmented and disassembled. Nests of angular rock fragments are marking the locations of preexisting larger rocks. Frequently it is possible to reconstruct larger rounded rocks from smaller angular fragments. In other cases transport after fragmentation obscured the relationship of the fragments. However, a strewn field of fragments is still reminiscent of the preexisting rock. Mechanical salt weathering could be a plausible explanation for the insitu fragmentation of larger rounded blocks into angular fragments. Impact or secondary air fall induced fragmentation produces very different patterns, as observed around impact crates on Earth. Salt weathering of rocks is a common process in terrestrial environments. Salt crystallization in capillaries causes fragmentation of rocks, irrespective of the process of salt transportation and concentration. On Earth significant salt weathering can be observed in different climatic environments: in the transition zone of alluvial aprons and salt playas in desserts and in dry valleys of Antarctica. In terrestrial semi-arid areas the salt is transported by salt solution, which is progressively concentrated by evaporation. In Antarctic dry valleys freeze-thaw cycles causes salt transportation and crystallization resulting in rock fragmentation. This salt induced process can lead to complete destruction of rocks and converts rocks to fine sand. The efficient breakdown of rocks is dominating the landscape in some dry valleys of the Earth but possibly also on Mars. (Malin, 1974

  5. Stratigraphy and petroleum potential of Berea sandstone in Larkin and Williams fields, Midland and Bay Counties, Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Gunn, G.R.

    1986-08-01

    The Berea is an Early Mississippian deltaic sandstone confined to the eastern side of the Michigan basin. The Berea Sandstone consists of three members: upper, middle, and lower. Only the upper and middle members are present in the Larkin and Williams area. The middle member is the main reservoir, and scanning electron microscope studies indicate that the sand has primary, interparticle porosity with some secondary leaching of interstitial clays and feldspathic grains. Over the past 5 years, wells have been drilled 2500 ft into the Berea along a structure between Midland and Bay Counties. The structure is a northwest-southeast-trending anticline that plunges northwest into the basin. A review of the wells drilled along this anticline reveals a progression of structural-stratigraphic traps within the middle Berea member. At the southeast end of each reservoir (the updip end), a stratigraphic pinchout cuts across the middle Berea member creating a barrier to oil migrating updip along the northwest-southeast structural trend. These pinch-outs are narrow with a north-northeast orientation and are considered to be abandoned, mud-filled channels cutting across an apron sheet sand, which is interpreted to be a beach-strand-plain complex. Because the middle Berea member has excellent porosity and permeability, many wells in the field have flowed oil with initial production ranging between 75 and 350 BOPD. The original oil in place is estimated to be more than 23 million bbl of oil; only 1.4 million bbl of oil has been produced.

  6. Occupational exposure of apprentices in radiology in the field of professional training

    Energy Technology Data Exchange (ETDEWEB)

    Costa, R. F., E-mail: rogercosta1@hotmail.com [Universidade Estadual de Goias, Unidade Universitaria de Morrinhos, Rua 14, 625, Jardim das Americas, Cep 75650-000, Morrinhos, Goias (Brazil)

    2014-08-15

    The good economic moment of our country has been providing an increase of courses in technical and technological area mainly in the field of radiology, which has raised the number of apprentices in the field of stage in clinics and hospitals. However, the shortage of placements and the fact that many of these students are workers, has forced the institutions of technical education to seek alternatives for the students to meet the workload of the stage in a time as short as possible. For this reason, often the students are obliged to comply with up to 10 hours of internship in a single day, in companies that often are not in accordance with the standards of radiological protection. What has worried the authorities of Goiania, because they believe that this exposure can raise the dose received. It is known that every person who works with X-ray diagnostics should use, during their work day and while stay in controlled area, individual dosimeter reading indirect, changed monthly. However, in practice these apprentices do not use the meter for monitoring of doses in probationary period. In This way, we measure the doses received us trainees using monitors TLDs in the thoracic region with and without plumbiferous apron on stage with total workload of 150 hours, performed daily from Monday to Friday for 6 hours per day during 5 weeks and performed to Saturday and Sunday for 10 hours daily in 7.5 weekends, with X-ray equipment conventional. The results reveal that in none of the cases the dose reached the value of 0.2 mSv, which is the minimum limit of reading dosimeter. We conclude then that the stages of weekends, taken the preventive measures of radiological protection are safe and can be performed without any prejudice with regard to the dose received, when compared to those of lower daily hourly load. (Author)

  7. Air freight in the Stockholm region with focus on Eskilstuna Airport

    Directory of Open Access Journals (Sweden)

    Kjell-Åke Allan Brorsson

    2016-02-01

    Full Text Available Purpose: The purpose of this article is to analyse the conditions for commencing air freight operations at the regional Eskilstuna Airport in Sweden, which require investments in airport infrastructure of at least SEK 140 –180 million. Design/ methodology: The qualitative data collection for the study was carried out through open-ended interviews with representatives of airport management, staff, representatives of residents, and actors and stakeholders in the field. In addition, much written material was collected from different authorities. Document analysis was used to systematically evaluate and review the collected documents. Content analysis was applied to organize collected data into categories. Based on the reports, decisions, environmental scanning and interviews, the data have been coded and categorized in tables via thematic analysis. Findings: The major findings of the study are that Eskilstuna Airport lacks cargo facilities and has limited apron space, and that there is strong competition from four other airports in the Stockholm region. The prospects for permanent air freight operations at Eskilstuna Airport are therefore not favourable in the current situation. However, if the development of Eskilstuna Logistics Park and the concept of inter modal highway-rail transportation are successful, they could serve as a major driving force for the development of air cargo. Furthermore, with sustainable development as a guiding principle, there is great potential to develop an airport with a high standard of environmental profile. Originality/ value: My findings are of great value to managers of airports and cargo airlines, as they highlight some of the competition aspects associated with engaging in air cargo at regional airports. The study fills a gap in existing research whose main focus is environmental issues concerning airports in general.

  8. A new design of a lead-acrylic shield for staff dose reduction in radial and femoral access coronary catheterization

    International Nuclear Information System (INIS)

    Today's standard radiation protection during coronary angiography and percutaneous coronary interventions is the combined use of lead acrylic shields and table-mounted lower body protection. Ambient dose measurements, however, have shown that these protection devices need improvement. Using an anthropomorphic physical phantom, various scenarios were investigated with respect to personnel exposure: (a) enlarging the shield (b) adding a flexible protective curtain to the bottom side of the shield, and (c) application of radioprotective patient drapes. For visualization of the dose reduction effect, Monte Carlo simulations were performed. The flexible curtain in contact with the patient's body reduces the ambient dose rate at the operator's position by up to (87.5 % ± 7.1) compared to the situation with the bare shield. The use of both the flexible curtain and the patient drape reduces the ambient dose rate by up to (90.8 % ± 7). Similar results were achieved for the assisting personnel when they were positioned next to the operator. In addition, the enlarged shield provides better protection of the head region of tall operators. Adding a flexible protective curtain to the bottom side of the shield can protect operators from high doses, especially for body parts which are not protected by lead aprons, e.g. head, and eye lenses. This may be important with respect to lower dose limits for eye lenses in future. The protective effect in real-life working conditions is still being evaluated in an ongoing clinical study.

  9. Assessment of radiation protection of patients and staff in interventional procedures in four Algerian hospitals

    International Nuclear Information System (INIS)

    This study was aimed to assess patient dosimetry in interventional cardiology (IC) and radiology (IR) and radiation safety of the medical operating staff. For this purpose, four major Algerian hospitals were investigated. The data collected cover radiation protection tools assigned to the operating staff and measured radiation doses to some selected patient populations. The analysis revealed that lead aprons are systematically worn by the staff but not lead eye glasses, and only a single personal monitoring badge is assigned to the operating staff. Measured doses to patients exhibited large variations in the maximum skin dose (MSD) and in the dose area product (DAP). The mean MSD registered values are as follows: 0.20, 0.14 and 1.28 Gy in endoscopic retrograde cholangio-pancreatography (ERCP), coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA) procedures, respectively. In PTCA, doses to 3 out of 22 patients (13.6 %) had even reached the threshold value of 2 Gy. The mean DAP recorded values are as follows: 21.6, 60.1 and 126 Gy cm2 in ERCP, CA and PTCA procedures, respectively. Mean fluoroscopic times are 2.5, 5 and 15 min in ERCP, CA and PTCA procedures, respectively. The correlation between DAP and MSD is fair in CA (r = 0.62) and poor in PTCA (r = 0.28). Fluoroscopic time was moderately correlated with DAP in CA (r = 0.55) and PTCA (r = 0.61) procedures. Local diagnostic reference levels (DRLs) in CA and PTCA procedures have been proposed. In conclusion, this study stresses the need for a continuous patient dose monitoring in interventional procedures with a special emphasis in IC procedures. Common strategies must be undertaken to substantially reduce radiation doses to both patients and medical staff. (authors)

  10. The Kohuamuri siliceous sinter as a vector for epithermal mineralisation, Coromandel Volcanic Zone, New Zealand

    Science.gov (United States)

    Hamilton, Ayrton; Campbell, Kathleen; Rowland, Julie; Browne, Patrick

    2016-04-01

    The Kohuamuri siliceous sinter is the largest known fossil hot-spring system in the Hauraki Goldfield, a 200 × 40 km volcanic terrain with at least 50 adularia-illite epithermal deposits formed 16.3-5.6 Ma within the Coromandel Volcanic Zone, New Zealand. The sinter is associated with rhyolite and ignimbrite of the Whitianga Caldera (Miocene-Pliocene) and consists of two deposits, the Kohuamuri deposit itself, a large in situ outcrop (47,000 m2) and its associated sinter boulder field (4500 m2), and the Kaitoke deposit 900 m to the southwest, comprising boulders in a landslide situated on a normal fault. The well-preserved macroscopic and microscopic textures at Kohuamuri are similar to actively forming and ancient hot-spring deposits elsewhere, derived from deep circulating, magmatically heated, near-neutral pH alkali chloride fluids oversaturated in amorphous silica and that discharge at the Earth's surface at ≤100 °C. Lithofacies, petrography, mineralogy, as well as trace element concentrations of the Kohuamuri/Kaitoke deposits were used to locate likely palaeo-thermal conduits from the deep reservoir and to reconstruct the palaeoenvironmental setting of the siliceous sinter as an aid to assessing the economic potential of the ancient geothermal system. Both deposits contain the high-temperature (>75 °C) geyserite lithofacies, with the Kohuamuri deposit also exhibiting textures affiliated with cooler middle and distal sinter apron areas, as well as geothermally influenced marsh facies. Trace element analysis of sinter lithofacies revealed concentrations and zonations of Au, Ag, base metals (Pb, Cu, Zn) and pathfinder elements (As, Sb) associated with epithermal deposits, elevated in the proximal vent area, and providing evidence of possible Au and Ag ore mineralisation at depth. The methodology used in this study could be utilised globally to identify and assess as yet unidentified epithermal deposits.

  11. Geology of the Yucca Mountain Site Area, Southwestern Nevada, Chapter in Stuckless, J.S., ED., Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste (Volume 1)

    International Nuclear Information System (INIS)

    Yucca Mountain in southwestern Nevada is a prominent, irregularly shaped upland formed by a thick apron of Miocene pyroclastic-flow and fallout tephra deposits, with minor lava flows, that was segmented by through-going, large-displacement normal faults into a series of north-trending, eastwardly tilted structural blocks. The principal volcanic-rock units are the Tiva Canyon and Topopah Spring Tuffs of the Paintbrush Group, which consist of volumetrically large eruptive sequences derived from compositionally distinct magma bodies in the nearby southwestern Nevada volcanic field, and are classic examples of a magmatic zonation characterized by an upper crystal-rich (> 10% crystal fragments) member, a more voluminous lower crystal-poor (10Be and 36Cl cosmogenic dating methods to determine the length of time bedrock outcrops and hillslope boulder deposits were exposed to cosmic rays, which then served as a basis for calculating long-term erosion rates. The results indicate rates ranging from 0.04 to 0.27 cm/k.y., which represent the maximum downcutting along the summit of Yucca Mountain under all climatic conditions that existed there during most of Quaternary time. Associated studies include the stratigraphy of surficial deposits in Fortymile Wash, the major drainage course in the area, which record a complex history of four to five cut-and-fill cycles within the channel during middle to late Quaternary time. The last 2 to 4 m of incision probably occurred during the last pluvial climatic period, 22 to 18 ka, followed by aggradation to the present time

  12. Evaluation of the enter surface dose, dose in organ and E effective dose, received by personnel and patients in studies of endoscopic retrograde cholangeopancreatography in the General Hospital of Mexico; Evaluacion de la dosis de entrada superficie, dosis en organo y dosis efectiva E, recibidas por personal y pacientes en estudios de colangiopancreatografia retrograda endoscopica en el Hospital General de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, S.; Gama T, G. [Calidad XXI SA de CV, Zacatecas 67-007 Col. Roma, 06700 Mexico D.F. (Mexico); Beristain, M.; Espino, H. [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06726 Mexico D.F. (Mexico)]. e-mail: cxxi@prodigy.net.mx

    2006-07-01

    The ESD for patient and personal is measured: gastroenterologuist endoscopist G1, A1 Assistant and A2 instrumentist that carried out 22 independent therapeutic procedures of CPRE, in a fluoroscopy equipment Toshiba trademark with tube under the table, operated in automatic exposure mode, CAE to average tensions of 80 kVp. The measurement is carried out with film dosemeters of double emulsion Kodak Type 2 trademark, calibrated in terms of H{sup *} for the energy of the {sup 137} Cs, first it is determined the films sensitivity like function of the optical density DO, and second the ESD for the effective energy of the radiation beam (50 keV), in three different points from the dosemeter (C, D and H). The films was placed for the personnel in: right hand, front (eye), thyroid and thorax (under D and out F of the lead apron); in the case of the patient three positions were used: thorax, hepatic region and pelvis. The mean values of the ESD and it standard deviation SD in mGy units are determined by: study, personnel, film position in doctor and patient, dosemeter measurement point. The calculated doses in organ are also determined for the patient in the thorax region, liverwort and pelvis its are agreement with the NRPB SR 262 report. Finally the H{sub E} and E for medical personnel and patients are estimated demonstrating that its are not exceeded the annual dose limits for the case of the OEP. In the case of the the OEP have for the D thorax an ESD{sub max} = 0.04 mGy that one corresponds an H{sub E} = 0.02 and E = 0.01 mSv. (Author)

  13. The EURADOS/CONRAD activities on radiation protection dosimetry in medicine

    International Nuclear Information System (INIS)

    Full text: This presentation gives an overview on the research activities that EURADOS coordinates in the field of radiation protection dosimetry in medicine. EURADOS is an organization founded in 1981 to advance the scientific understanding and the technical development of the dosimetry of ionising radiation in the fields of radiation protection, radiobiology, radiation therapy and medical diagnosis by promoting collaboration between European laboratories. EURADOS operates by setting up Working Groups dealing with particular topics. Currently funded through the CONRAD project of the 6th EU Framework Programme, EURADOS has working groups on Computational Dosimetry, Internal Dosimetry, Complex mixed radiation fields at workplaces, and Radiation protection dosimetry of medical staff. The latter working group coordinates and promotes European research for the assessment of occupational exposures to staff in therapeutic and diagnostic radiology workplaces. Research is coordinated by sub-groups covering three specific areas: 1: Extremity dosimetry in nuclear medicine and interventional radiology: this sub-group coordinates investigations in the specific fields of the hospitals and studies of doses to different parts of the hands, arms, legs and feet; 2: Practice of double dosimetry: this sub-group reviews and evaluates the different methods and algorithms for the use of dosemeters placed above and below lead aprons, especially to determine personal doses to cardiologists during cardiac catheterisation, but also in CT-fluoroscopy and some nuclear medicine developments (e.g. use of Re-188); and 3: Use of electronic personal dosemeters in interventional radiology: this sub-group coordinates investigations in laboratories and hospitals, and intercomparisons with passive dosemeters with the aim to enable the formulation of standards. (author)

  14. Radiation exposure to patients and medical staff in hepatic chemoembolisation interventional procedures in Recife, Brazil

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate patient and medical staff absorbed doses received from trans-arterial chemoembolisation of hepatocellular carcinoma, which is the most common primary liver tumour worldwide. The study was performed in three hospitals in Recife, capital of the state of Pernambuco, located in the Brazilian Northeastern region. Two are public hospitals (A and B), and one is private (C). For each procedure, the number of images, irradiation parameters (kV, mA and fluoroscopy time), the air kerma-area product (PKA) and the cumulative air kerma (Ka,r) at the reference point were registered. The maximum skin dose (MSD) of the patient was estimated using radiochromic film. For the medical staff dosimetry, thermoluminescence dosemeters (TLD-100) were attached next to the eyes, close to the thyroid (above the shielding), on the thorax under the apron, on the wrist and on the feet. The effective dose to the staff was estimated using the algorithm of von Boetticher. The results showed that the mean value of the total PKA was 267.49, 403.83 and 479.74 Gy cm2 for Hospitals A, B and C, respectively. With regard to the physicians, the average effective dose per procedure was 17 μSv, and the minimum and maximum values recorded were 1 and 41 μSy, respectively. The results showed that the feet received the highest doses followed by the hands and lens of the eye, since the physicians did not use leaded glasses and the equipment had no lead curtain. (authors)

  15. SU-E-P-20: Personnel Lead Apparel Integrity Inspection: Where We Are and What We Need?

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S; Zhang, J; Anaskevich, L; Oates, E [University of Kentucky, Lexington, KY (United States)

    2015-06-15

    Purpose: In recent years, tremendous efforts have been devoted to radiation dose reduction, especially for patients who are directly exposed to primary radiation or receive radiopharmaceuticals. Limited efforts have been focused on those personnel who are exposed to secondary radiation while fulfilling their work responsibilities associated with diagnostic imaging and image-guided interventions. Occupational exposure is compounded in daily practice and can lead to a significant radiation dose over time. Personnel lead apparel is a well-accepted engineering control to protect healthcare workers when radiation is inevitable. The question is, do we have a nationally established program to protect personnel? This study is to investigate the lead apparel inspection programs among the USA. Methods: A series of surveys of state regulations, the University Health System Consortium, and federal regulations and regulations determined by accrediting bodies were conducted. The surveys were used to determine the current status of lead apparel programs regarding integrity inspections. Based on the survey results, a thorough program was proposed accordingly. Results: Of 50 states, seventeen states and Washington D.C. require lead apparel integrity inspections within their state regulations. Eleven of these states specify that the inspection is required on an annual basis. Two of these states require lead apron integrity checks to be performed semi-annually. Eleven out of the two hundred academic medical centers surveyed responded. The results show that the method (visually vs. fluoroscopy) used to conduct lead apparel integrity checks differ greatly amongst healthcare organizations. The FDA, EPA, CRCPD and NCRP require lead apparel integrity checks. However, the level of policies is different. A standard program is not well established and clearly there is a lack of standardization. Conclusion: A program led by legislative (state or federal government) and with specific frequency

  16. Determination of Doses for X-Ray Examinations of Paranasal Sinuses of Children

    International Nuclear Information System (INIS)

    The knowledge of the absorbed doses during X-ray examination is very important, especially in paediatric radiology in order to improve radiation protection. In childhood, the paranasal sinuses diseases are very frequent and the development of sinuses has some specialities which has to be taken into consideration in X-ray diagnostics. The aim of this work was the determination of the relative doses on the thyroid gland and eyes, in respect to the entrance dose on the anthropomorphic child phantom (CIRS). The entrance doses on the phantom to the entrance dose on patients of similar age. Simultaneously the influence of human working method was studied, i.e. the performance of the radiological technicians. The age of the patients varied from 7 to 15 years, the child phantom was equivalent to 10 years age. A protective lead apron on the necks of both children and phantom was used. Doses were measured with radiophotoluminescence (RPL) and thermoluminescence (TL) dosemeters. The mean doses on the thyroid and the eyes measured in the phantom after 10 expositions were 0.20 ± 0.05 mSv, and 0.32 ± 0.02 mSv, respectively. Relative doses were calculated in relation to entrance dose of 9.96 mSv for 10 exposures, and the results were 0.02 and 0.03 for the thyroid gland and the eyes, respectively. The dosimetry results on 45 patients showed that there was a good correlation between measured doses and the body mass index (BMI). The mean entrance dose measured on the 45 patients was 0.97 ± 0.08 mSv.(author)

  17. A new design of a lead-acrylic shield for staff dose reduction in radial and femoral access coronary catheterization

    Energy Technology Data Exchange (ETDEWEB)

    Eder, H. [Deptartment of Radiation Protection (Germany); Seidenbusch, M.C.; Treitl, M. [Muenchen Univ. Clinical Center (Germany). Inst. for Clinical Radiology; Gilligan, P. [Mater Private Hospital, Dublin (Ireland). Medical Physics

    2015-10-15

    Today's standard radiation protection during coronary angiography and percutaneous coronary interventions is the combined use of lead acrylic shields and table-mounted lower body protection. Ambient dose measurements, however, have shown that these protection devices need improvement. Using an anthropomorphic physical phantom, various scenarios were investigated with respect to personnel exposure: (a) enlarging the shield (b) adding a flexible protective curtain to the bottom side of the shield, and (c) application of radioprotective patient drapes. For visualization of the dose reduction effect, Monte Carlo simulations were performed. The flexible curtain in contact with the patient's body reduces the ambient dose rate at the operator's position by up to (87.5 % ± 7.1) compared to the situation with the bare shield. The use of both the flexible curtain and the patient drape reduces the ambient dose rate by up to (90.8 % ± 7). Similar results were achieved for the assisting personnel when they were positioned next to the operator. In addition, the enlarged shield provides better protection of the head region of tall operators. Adding a flexible protective curtain to the bottom side of the shield can protect operators from high doses, especially for body parts which are not protected by lead aprons, e.g. head, and eye lenses. This may be important with respect to lower dose limits for eye lenses in future. The protective effect in real-life working conditions is still being evaluated in an ongoing clinical study.

  18. Radiation protection clothes in X-ray diagnostics

    International Nuclear Information System (INIS)

    One of the basic principles in radiation protection is the usage of shielding to protect against ionizing radiation. Initial lead was already the best material in radiation protection, but especially in the last few years under the background of losing weight more and more often lead has been replaced by or mixed with other materials with lower atomic number. Since the established method of determination the attenuation equivalents was aligned to lead as protective material and the occurring fluorescence, caused by this 'new' materials, was not taken into account, miss-estimations of their protective effect in comparison to lead occurred. One focus of this work is the comparison of the new procedure for determination of shielding properties in the inverse broad-beam geometry (in accordance with DIN 6857-1 2009), which was developed from PTB in the 'DIN Normenausschuss Radiologie' with our cooperation within the scope of this thesis, with the established methods (in accordance with DIN EN 61331-1 2002). It was found, that the attenuation measurements in the inverse broad-beam geometry show equivalent results to the measurements in the broad beam, also with lead-free and lead-reduced protective clothing and that no miss-estimation occurred like it does when taking the measurements in the narrow beam. Afterward the new procedure was applied to an existing stock of aprons, while it turned out, that the testing method DIN 6857-1 has yet to prevail respectively that the manufacturers are only on track to develop the appropriate protective materials. A further part of this work deals with the recognizability and the validation of defects (cracks, holes...) in the protective material. So the smallest still recognizable sizes of the defects were determinated for the individual geometries as well as for x-ray exposures, which are clearly at an advantage. (author)

  19. Radiation exposure to patients and medical staff in hepatic chemoembolisation interventional procedures in Recife, Brazil.

    Science.gov (United States)

    Khoury, H J; Garzon, W J; Andrade, G; Lunelli, N; Kramer, R; de Barros, V S M; Huda, A

    2015-07-01

    The purpose of this study was to evaluate patient and medical staff absorbed doses received from transarterial chemoembolisation of hepatocellular carcinoma, which is the most common primary liver tumour worldwide. The study was performed in three hospitals in Recife, capital of the state of Pernambuco, located in the Brazilian Northeastern region. Two are public hospitals (A and B), and one is private (C). For each procedure, the number of images, irradiation parameters (kV, mA and fluoroscopy time), the air kerma-area product (PKA) and the cumulative air kerma (Ka,r) at the reference point were registered. The maximum skin dose (MSD) of the patient was estimated using radiochromic film. For the medical staff dosimetry, thermoluminescence dosemeters (TLD-100) were attached next to the eyes, close to the thyroid (above the shielding), on the thorax under the apron, on the wrist and on the feet. The effective dose to the staff was estimated using the algorithm of von Boetticher. The results showed that the mean value of the total PKA was 267.49, 403.83 and 479.74 Gy cm(2) for Hospitals A, B and C, respectively. With regard to the physicians, the average effective dose per procedure was 17 µSv, and the minimum and maximum values recorded were 1 and 41 µSy, respectively. The results showed that the feet received the highest doses followed by the hands and lens of the eye, since the physicians did not use leaded glasses and the equipment had no lead curtain. PMID:25870436

  20. Dental radiological protection - an investigation of the status in general practice in the Republic of South Africa

    International Nuclear Information System (INIS)

    The historical events relating to the discovery of x-rays in 1895 by W.C. Roentgen, are briefly sketched and previous surveys on radiological protection in dental practice are critically examined. The most important factors influencing the radiation dose in dental radiography are discussed, as well as the biological effects of ionizing radiation. The aims and objectives of the study were to carry out a survey on a representative sample of dentists in private practice to ascertain the current status of dental radiological protection, to analyse the results and to compare them to the findings of surveys performed in other countries. The final aim was to be able to make, wherever necessary and possible, recommendations to improve the standard of radiation protection in general practice. A personal survey was made of 141 randomly-selected dental practices throughout the country. Observations and measurements were made and a questionnaire was completed by the investigator. The findings were subsequently analysed statistically by a computer and compared to both various norms and the findings of previous surveys carried out overseas. The results showed conclusively that, whereas, in general, the hazard to the dentist, staff members and persons in the environs, from dental radiology is low, to the patient it is significant. Various specific recommendations made include the replacement of the old low-kilovoltage x-ray machines, short, unlined plastic dental cones and faulty exposure timers. They include the promotion of the use of Speed Group E Film, the Paralleling technique, correct film processing techniques, professional judgement in the use of radiographs, leaded aprons, thyroid shields film badges and continuing education courses. The compulsory recording in the patient's own identity book of each patient exposure to x-radiation, from all sources, is also recommended

  1. Relative sea level changes and carbonate factories of the Urgonian platform, Hauterivian-Aptian, Vercors, France

    Energy Technology Data Exchange (ETDEWEB)

    Jacquin, T.; Vail, P.R. (Rice Univ., Houston, TX (United States))

    1993-09-01

    Long term second-order and short term third-order relative sea level changes control the development of the Urgonian platform in the French western Alps. At a second-order scale the Urgonian platform develops over the drowned late Berriasian-middle Valanginian platform. During the regressive phase, the platform progrades tens of kilometers toward the southeast. During the transgressive phase, the platform aggrades, backsteps, and then drowns. Subsidence analysis indicates this second-order cycle is controlled by changes in rates of subsidence or possibly tectono-eustasy. At a third-order scale, two types of carbonate factories alternate within the Urgonian platform, highstand and lowstand. The Urgonian facies is a product of highstand factories which changes laterally into platform-rim buildups with corals and stromatoporids and rapidly thins basinward by sediment starvation. Both the bioclastic turbidites and the large seismic-scale clinoforms visible in the outcrops of the southern Vercors are the products of the lowstand factories. These lowstand turbidites and shoal-water prograding grainstones consist of three distinct units: a lower basinal sheet of platform-derived massive grainstones, a thick apron of fine-grained turbidites and mudstones with proximal channels, some of which are filled with coarse grainstones, and a prograding unit pinching out at the offlap break of the previous highstand in the area of the stromatoporids. The prograding grainstones are matrix-poor cross-stratified beds in the shallow water areas and facies change to mudstones in the basin. The lack of boundstones in the proximal parts of the lowstand prograding intervals, together with the lack of well-developed early cementation, ooids, and aggregates suggest that these lowstand factories were temperate-water systems. They contrast with the Urgonian highstand factories that were particularly well equipped to keep up with sea level rises such as modern tropical carbonates.

  2. Effect of pregnant mare serum gonadotrophin injection on litter size in young Etawah-cross does

    Directory of Open Access Journals (Sweden)

    N.M Artiningsihi

    1996-03-01

    Full Text Available The incidence of twins and/or multiple births in 20 heads of young Etawah-cross does was studied following oestrous synchronization using intravaginal sponges containing 60 mg medroxyprogesterorle acetate (Repromap for 15 days . Twenty four hours priorto sponges withdrawal, the does were injected with pregnant mare serum gonadotrophin (PMSG at dose rates of 0 (Group A, 10 (Group B, 15 (Group C and 20 iu/kg (Group D body weight. Amature buck fitted with an apron was used to detect the onset of oestrus at every four hours. The oestrous doe was naturally mated twice, 12 hours after onset of oestrus and 10 hours later. About 3-5 days after oestrus, all does were subjected to mid-ventral laparoscopy to detect ovulation rate . Two months after mating all does were subjected to pregnancy test using diagnostic ultrasonography. Results showed that all does exhibited clear sign of oestrus. The onset of oestrus occurred 15-43 hours after sponges withdrawal or 39-59 hours after PMSG injection. Does injected with PMSG (Groups B, C and D showed oestrus 16-21 hours earlier (P0 .05 than that of control (Group A . However, there was no significant differences among the PMSG-treated groups . Ovulation rates increased from 1.0 in Group Ato 1.8 in Group B and 2.6 in bah Groups Cand D. Average litter size in Groups A, B, C and D were 1.0, 1.8, 2.4 and 1.0, respectively. It was concluded that injection of 15 iu PMSG/kg body weight gave the best result for increasing litter size in young Etawah-cross does .

  3. The variation of estrus in endocrinological levels and behaviour in endocrinological ewes throughout the year

    International Nuclear Information System (INIS)

    An investigation was carried out to determine reproductive activity of endocrinological and behavior in Akkaraman sheep (n=20.25 years, 74±7.7 body weight) throughout the year in the Middle Anatolian (39 57 deg. N 32.53 deg. W). The onset of estrous was detected by using apron ram for 30-minute period twice a day. Blood samples collected twice a week were analyzed by Enzyme immunoassay for progesterone (p4), by Radio immunoassay for estradiol. Estrus cycle lengths and estrous lengths were (mean±SD) 18.33±1.03 day, 35.16±5.95 hours, respectively. The breeding season lengths were 283±63.36 day and 229.64±63.74 day according to hormonal and behavior data, respectively (P≤0.0032). Frequency of occurrence estrus was high between August and March however the highest peak was in October. The lowest peaks were both in June and July. Plasma progesterone levels were changed between 0.01-9 ng/ml throughout the year and 0.2-0.16 ng/ml in anoestrus. P4 level of 11-th day of luteal phase of estrus was 3.73±1.50 ng/ml (n=11). Plasma estradiol level was 8.42±2.51 pg/ml between of 1-st and 2-nd day and 3.50±1.50 pg/ml on day 15. Second peak of estradiol determined on day 11 of estrus cycle was 6.09±2.87 pg/ml (n=11)

  4. Ebola virus disease surveillance and response preparedness in northern Ghana

    Science.gov (United States)

    Adokiya, Martin N.; Awoonor-Williams, John K.

    2016-01-01

    Background The recent Ebola virus disease (EVD) outbreak has been described as unprecedented in terms of morbidity, mortality, and geographical extension. It also revealed many weaknesses and inadequacies for disease surveillance and response systems in Africa due to underqualified staff, cultural beliefs, and lack of trust for the formal health care sector. In 2014, Ghana had high risk of importation of EVD cases. Objective The objective of this study was to assess the EVD surveillance and response system in northern Ghana. Design This was an observational study conducted among 47 health workers (district directors, medical, disease control, and laboratory officers) in all 13 districts of the Upper East Region representing public, mission, and private health services. A semi-structured questionnaire with focus on core and support functions (e.g. detection, confirmation) was administered to the informants. Their responses were recorded according to specific themes. In addition, 34 weekly Integrated Disease Surveillance and Response reports (August 2014 to March 2015) were collated from each district. Results In 2014 and 2015, a total of 10 suspected Ebola cases were clinically diagnosed from four districts. Out of the suspected cases, eight died and the cause of death was unexplained. All the 10 suspected cases were reported, none was confirmed. The informants had knowledge on EVD surveillance and data reporting. However, there were gaps such as delayed reporting, low quality protective equipment (e.g. gloves, aprons), inadequate staff, and lack of laboratory capacity. The majority (38/47) of the respondents were not satisfied with EVD surveillance system and response preparedness due to lack of infrared thermometers, ineffective screening, and lack of isolation centres. Conclusion EVD surveillance and response preparedness is insufficient and the epidemic is a wake-up call for early detection and response preparedness. Ebola surveillance remains a neglected public

  5. Study of the radiological procedures used in odontologic clinics of Boa Vista, Roraima, Brazil; Estudo dos procedimentos radiologicos nos consultorios odontologicos de Boa Vista, Roraima

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Jaberson Luiz Leitao

    2002-04-01

    The purpose of this study was to evaluate the radiological procedures used at the odontologic clinics of Boa Vista, Roraima-Brazil. The following parameters were recorded: field diameter, half value layer, total filtration, discrepancy between the preset and the applied kilovoltage and exposure time. Dose to the patient's skin from radiography of the upper molar tooth was also estimated. The results showed that 78% of the inspected units had field diameters larger than 6,0 cm, which is outside the limits recommended by the Brazilian Health Ministry. The results also showed that 14% of the equipment presented a discrepancy of more than 10% between preset and applied kilovoltage. On the other hand, the discrepancy between preset and applied exposure time is higher than 10% in 70% of the tested units. The total filtration of 77% units is lower than 1,5 mm of Al, a value recommended by the Brazilian Health Ministry for equipment that operates in the range of 50 kV to 70 kV. The survey also indicates that for 35% of the units the entrance dose in high than 3,5 mGy that is the reference value established by the Brazilian Health Ministry for dental radiography with film type. It was observed that the majority of the clinics use neither aprons nor collars for patients and that films are processed manually, without controlling temperature or processing time. Based on the results obtained it is strongly recommended that a quality control program be implemented in dental radiological clinics in Boa Vista, Roraima. (author)

  6. SU-E-P-46: Clinical Acceptance Testing and Implementation of a Portable CT Unit

    Energy Technology Data Exchange (ETDEWEB)

    LaFrance, M; Marsh, S; Hicks, R; O’Donnell-Moran, G [Baystate Health Systems, Inc., Springfield, MA (United States)

    2015-06-15

    Purpose: Planning for the first installation in New England of a new portable CT unit to be used in the Operating Room required the integration of many departments including Surgery, Neurosurgery, Information Services, Clinical Engineering, Radiology and Medical Physics/Radiation Safety. Acceptance testing and the quality assurance procedures were designed to optimize image quality and patient and personnel radiation exposure. Methods: The vendor’s protocols were tested using the CT Dosimetry phantoms. The system displayed the CTDIw instead of the CTDIvol while testing the unit. Radiation exposure was compared to existing CT scanners from installed CT units throughout the facility. Brainlab measures all 4 periphery slots on the CT Dosimetry phantom. The ACR measures only the superior slot for the periphery measurement. A comprehensive radiation survey was also performed for several locations. Results: The CTDIvol measurements were comparable for the following studies: brain, C-Spine, and sinuses. However, the mobile CT measurements were slightly higher than other CT units but within acceptable tolerance if measured using the ACR method.Based on scatter measurements, it was determined if any personnel were to stay in the OR Suite during image acquisition that the appropriate lead apron and thyroid shields had to be worn.In addition, to reduce unnecessary scatter, there were two mobile 6 foot wide shields (1/16″ lead equivalent) available to protect personnel in the room and adjacent areas. Conclusion: Intraoperative CT provides the physician new opportunities for evaluation of the progression of surgical resections and device placement at the cost of increasing the amount of trained personnel required to perform this procedure. It also brings with it challenges to keep the radiation exposure to the patients and staff within reasonable limits.

  7. Solid cancer incidence among Chinese medical diagnostic x-ray workers, 1950-1995: Estimation of radiation-related risks.

    Science.gov (United States)

    Sun, Zhijuan; Inskip, Peter D; Wang, Jixian; Kwon, Deukwoo; Zhao, Yongcheng; Zhang, Liangan; Wang, Qin; Fan, Saijun

    2016-06-15

    The objective of this study was to estimate solid cancer risk attributable to long-term, fractionated occupational exposure to low doses of ionizing radiation. Based on cancer incidence for the period 1950-1995 in a cohort of 27,011 Chinese medical diagnostic X-ray workers and a comparison cohort of 25,782 Chinese physicians who did not use X-ray equipment in their work, we used Poisson regression to fit excess relative risk (ERR) and excess absolute risk (EAR) dose-response models for incidence of all solid cancers combined. Radiation dose reconstruction was based on a previously published method that relied on simulating measurements for multiple X-ray machines, workplaces and working conditions, information about protective measures, including use of lead aprons, and work histories. The resulting model was used to estimate calendar year-specific badge dose calibrated as personal dose equivalent (Sv). To obtain calendar year-specific colon doses (Gy), we applied a standard organ conversion factor. A total of 1,643 cases of solid cancer were identified in 1.45 million person-years of follow-up. In both ERR and EAR models, a statistically significant radiation dose-response relationship was observed for solid cancers as a group. Averaged over both sexes, and using colon dose as the dose metric, the estimated ERR/Gy was 0.87 (95% CI: 0.48, 1.45), and the EAR was 22 per 10(4) PY-Gy (95% CI: 14, 32) at age 50. We obtained estimates of the ERR and EAR of solid cancers per unit dose that are compatible with those derived from other populations chronically exposed to low dose-rate occupational or environmental radiation. PMID:26860236

  8. Study of the radiological procedures used in odontologic clinics of Boa Vista, Roraima, Brazil

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the radiological procedures used at the odontologic clinics of Boa Vista, Roraima-Brazil. The following parameters were recorded: field diameter, half value layer, total filtration, discrepancy between the preset and the applied kilovoltage and exposure time. Dose to the patient's skin from radiography of the upper molar tooth was also estimated. The results showed that 78% of the inspected units had field diameters larger than 6,0 cm, which is outside the limits recommended by the Brazilian Health Ministry. The results also showed that 14% of the equipment presented a discrepancy of more than 10% between preset and applied kilovoltage. On the other hand, the discrepancy between preset and applied exposure time is higher than 10% in 70% of the tested units. The total filtration of 77% units is lower than 1,5 mm of Al, a value recommended by the Brazilian Health Ministry for equipment that operates in the range of 50 kV to 70 kV. The survey also indicates that for 35% of the units the entrance dose in high than 3,5 mGy that is the reference value established by the Brazilian Health Ministry for dental radiography with film type. It was observed that the majority of the clinics use neither aprons nor collars for patients and that films are processed manually, without controlling temperature or processing time. Based on the results obtained it is strongly recommended that a quality control program be implemented in dental radiological clinics in Boa Vista, Roraima. (author)

  9. Historical Patterns in the Types of Procedures Performed and Radiation Safety Practices Used in Nuclear Medicine From 1945-2009.

    Science.gov (United States)

    Van Dyke, Miriam E; Drozdovitch, Vladimir; Doody, Michele M; Lim, Hyeyeun; Bolus, Norman E; Simon, Steven L; Alexander, Bruce H; Kitahara, Cari M

    2016-07-01

    The authors evaluated historical patterns in the types of procedures performed in diagnostic and therapeutic nuclear medicine and the associated radiation safety practices used from 1945-2009 in a sample of U.S. radiologic technologists. In 2013-2014, 4,406 participants from the U.S. Radiologic Technologists (USRT) Study who previously reported working with medical radionuclides completed a detailed survey inquiring about the performance of 23 diagnostic and therapeutic radionuclide procedures and the use of radiation safety practices when performing radionuclide procedure-related tasks during five time periods: 1945-1964, 1965-1979, 1980-1989, 1990-1999, and 2000-2009. An overall increase in the proportion of technologists who performed specific diagnostic or therapeutic procedures was observed across the five time periods. Between 1945-1964 and 2000-2009, the median frequency of diagnostic procedures performed substantially increased (from 5 wk to 30 wk), attributable mainly to an increasing frequency of cardiac and non-brain PET scans, while the median frequency of therapeutic procedures performed modestly decreased (from 4 mo to 3 mo). Also a notable increase was observed in the use of most radiation safety practices from 1945-1964 to 2000-2009 (e.g., use of lead-shielded vials during diagnostic radiopharmaceutical preparation increased from 56 to 96%), although lead apron use dramatically decreased (e.g., during diagnostic imaging procedures, from 81 to 7%). These data describe historical practices in nuclear medicine and can be used to support studies of health risks for nuclear medicine technologists. PMID:27218293

  10. The ABC transporter ABCG29 is involved in H2O2 tolerance and biocontrol traits in the fungus Clonostachys rosea.

    Science.gov (United States)

    Dubey, Mukesh; Jensen, Dan Funck; Karlsson, Magnus

    2016-04-01

    For successful biocontrol interactions, biological control organisms must tolerate toxic metabolites produced by themselves or plant pathogens during mycoparasitic/antagonistic interactions, by host plant during colonization of the plant, and xenobiotics present in the environment. ATP-binding cassette (ABC) transporters can play a significant role in tolerance of toxic compounds by mediating active transport across the cellular membrane. This paper reports on functional characterization of an ABC transporter ABCG29 in the biocontrol fungus Clonostachys rosea strain IK726. Gene expression analysis showed induced expression of abcG29 during exposure to the Fusarium spp. mycotoxin zearalenone (ZEA) and the fungicides Cantus, Chipco Green and Apron. Expression of abcG29 in C. rosea was significantly higher during C. rosea-C. rosea (Cr-Cr) interaction or in exposure to C. rosea culture filtrate for 2 h, compared to interaction with Fusarium graminearum or 2 h exposure to F. graminearum culture filtrate. In contrast with gene expression data, ΔabcG29 strains did not display reduced tolerance towards ZEA, fungicides or chemical agents known for inducing oxidative, cell wall or osmotic stress, compared to C. rosea WT. The exception was a significant reduction in tolerance to H2O2 (10 mM) in ΔabcG29 strains when conidia were used as an inoculum. The antagonistic ability of ΔabcG29 strains towards F. graminearum, Fusarium oxysporum or Botrytis cinerea in dual plate assays were not different compared with WT. However, in biocontrol assays ΔabcG29 strains displayed reduced ability to protect Arabidopsis thaliana leaves from B. cinerea, and barley seedling from F. graminearum as measured by an A. thaliana detached leaf assay and a barley foot rot disease assay, respectively. These data show that the ABCG29 is dispensable for ZEA and fungicides tolerance, and antagonism but not H2O2 tolerance and biocontrol effects in C. rosea. PMID:26520102

  11. Radiation protection in interventional radiology; Strahlenschutz in der interventionellen Radiologie

    Energy Technology Data Exchange (ETDEWEB)

    Adamus, R.; Loose, R.; Galster, M. [Klinikum Nuernberg Nord, Institut fuer Diagnostische und Interventionelle Radiologie, Nuernberg (Germany); Wucherer, M. [Klinikum Nuernberg Nord, Institut fuer Medizinische Physik, Nuernberg (Germany); Uder, M. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Institut fuer Radiologie, Erlangen (Germany)

    2016-03-15

    The application of ionizing radiation in medicine seems to be a safe procedure for patients as well as for occupational exposition to personnel. The developments in interventional radiology with fluoroscopy and dose-intensive interventions require intensified radiation protection. It is recommended that all available tools should be used for this purpose. Besides the options for instruments, x-ray protection at the intervention table must be intensively practiced with lead aprons and mounted lead glass. A special focus on eye protection to prevent cataracts is also recommended. The development of cataracts might no longer be deterministic, as confirmed by new data; therefore, the International Commission on Radiological Protection (ICRP) has lowered the threshold dose value for eyes from 150 mSv/year to 20 mSv/year. Measurements show that the new values can be achieved by applying all X-ray protection measures plus lead-containing eyeglasses. (orig.) [German] Die Anwendung ionisierender Strahlung in der Medizin scheint sowohl fuer Patienten als auch fuer beruflich exponierte Personen sicher zu sein. Die interventionellen Entwicklungen der letzten Jahre mit sehr durchleuchtungs- und dosisintensiven Eingriffen erfordern allerdings eine Intensivierung des Strahlenschutzes. Es empfiehlt sich, die zur Verfuegung stehenden Moeglichkeiten auszuschoepfen. Neben den Geraeteoptionen muss der Strahlenschutz am Eingriffstisch durch Bleilamellenaufstecker und montiertes Bleiglas intensiv betrieben werden. Besonderen Fokus muss auf den Schutz der Augen zur Kataraktvermeidung gelegt werden. Da dessen Ausbildung nach neuen Erkenntnissen moeglicherweise nicht mehr deterministisch zu sehen ist, hat die Internationale Strahlenschutzkommission (IRCP) den Grenzwert von 150 auf 20 Mikrosievert (mSv)/Jahr erniedrigt. Messungen belegen, dass unter Einhaltung aller Strahlenschutzmassnahmen plus Bleiglasbrille dieser einzuhalten ist. (orig.)

  12. Subaqueous systems fed by glacially derived hyperpycnal flows: a depositional model for Carboniferous-Permian sandstones of the Itarare Group, Parana Basin; Sistemas subaquosos alimentados por fluxos hiperpicnais glaciogenicos: modelo deposicional para arenitos do Grupo Itarare, Permocarbonifero da Bacia do Parana

    Energy Technology Data Exchange (ETDEWEB)

    Vesely, Fernando Farias [PETROBRAS, Rio de Janeiro, RJ (Brazil). E e P. Gerencia de Estratigrafia]. E-mail: vesely@petrobras.br

    2006-11-15

    The glacial Itarare Group constitutes the lower interval of the Carboniferous-Permian mega sequence in the Parana Basin. Thick glacially related sandstone reservoirs present in this unit contain gas and condensate sourced by Devonian marine shales. Based on outcrop data from the eastern basin margin, the sedimentary facies and stacking patterns were analyzed in order to propose a depositional model for these sandstone successions. It is suggested that the sandstones were deposited subaqueously as pro glacial fans due to melt water-derived highly concentrated hyperpycnal flows. Regional Itarare Group's stratigraphy can be expressed as several unconformity-bounded sequences deposited in a marine glaciated basin during repeated deglaciation episodes. The lower half of each sequence is constituted of thick sand-rich successions typically showing fining-upward and a retrogradational stacking pattern. Eleven facies were recognized, ranging from conglomerates to fine-grained sandstones, massive, graded or stratified. Conglomerates and cross-bedded coarse sandstones represent proximal Subaqueous deposits and were formed as ice-contact out wash fans/aprons due to melt water-derived hyper concentrated and concentrated flows and traction dominated bottom currents. These flows served as feeder systems to stratified, massive or graded turbiditic sandstone lobes deposited more distally. Parallel bedding and climbing ripples present in these beds were formed due to continuous aggradation from waxing and/or waning long-lived turbidity currents. These characteristics typify hyperpycnites and suggest that melt water derived hyperpycnal flows were the main trigger mechanisms to turbidity currents in the Itarare Group. (author)

  13. SU-E-I-57: Estimating the Occupational Eye Lens Dose in Interventional Radiology Using Active Personal Dosimeters Worn On the Chest

    International Nuclear Information System (INIS)

    Purpose: To provide a general formalism for determination of occupational eye lens dose based on the response of an active personal dosimeter (APD) worn at chest level above the radiation protection apron. Methods: The formalism consists of three factors: (1) APD conversion factor converting the reading at chest level (APDchest) to the corresponding personal dose equivalent at eye level, (2) Dose conversion factor transferring the measured dose quantity, Hp(10), into a dose quantity relevant for the eye lens dose, (3) Correction factor accounting for differences in exposure of the eye(s) compared to the exposure at chest level (e.g., due to protective lead glasses).The different factors were investigated and evaluated based on phantom and clinical measurements performed in an x-ray angiography suite for interventional cardiology. Results: The eye lens dose can be conservatively estimated by assigning an appropriate numerical value to each factor entering the formalism that in most circumstances overestimates the dose. Doing so, the eye lens dose to the primary operator and assisting staff was estimated in this work as D-eye,primary = 2.0 APDchest and D-eye,assisting = 1.0 APDchest, respectively.The annual eye lens dose to three nurses and one cardiologist was estimated to be 2, 2, 2, and 13 mSv (Hp(0.07)), respectively, using a TLD dosimeter worn at eye level. In comparison, using the formalism and APDchest measurements, the respective doses were 2, 2, 2, and 16 mSv (Hp(3)). Conclusion: The formalism outlined in this work can be used to estimate the occupational eye lens dose from the response of an APD worn on the chest. The formalism is general and could be applied also to other types of dosimeters. However, the numerical value of the different factors may differ from those obtained with the APD’s used in this work due to differences in dosimeter properties

  14. Support for Crater Count Chronometry and Evidence for Obliquity-driven Ice Deposition on Mars

    Science.gov (United States)

    Hartmann, William K.

    2007-10-01

    In December 2006, Malin et al. (Science) reported discovery of small Martian craters forming on Mars in the last 7 years. Diameters are 10 to 20 m for best detections. The formation rate for these craters is within a factor 2-3 of the rates I've used in the isochron system I developed at PSI (2005 Icarus) - which is within the uncertainty limits of factor 2-4 that I have quoted for the system. This supports the conclusion that order-of-magnitude ages can be measured for young, kilometer-scale Martian landforms, by counting small craters. If Malin et al. are right, the method can be refined to considerable precision in the future, by better measurement of small crater production rates. I have applied this dating system to tongue-shaped flows and debris aprons east of Hellas. These apparently involve flow of ice or ice/soil mixtures (Costard et al. 2002 Science). Surface features at lateral topographic scales of 10-20m and 3-6m depth consistently give ages of a few My to a few 10s My on the flow units, and older ages outside the flow units. This is true whether Hartmann, Malin, or Neukum cratering data are used. These ages are just in the range of the last few cycles of high obliquity (Laskar et al. 2002 Nature). Strikingly, the ice features are exactly in one of the two moderate-latitude regions with unusually high ice deposition at high obliquity, according to global climate models by Forget (2007 LPSC, private communication). I conclude that crater count chronometry is viable and we have evidence of localized high rates of ice deposition, and possible water release, on mid-latitude Mars within the last few tens of My.

  15. Catastrophic lava dome failure at Soufrière Hills Volcano, Montserrat, 12-13 July 2003

    Science.gov (United States)

    Herd, Richard A.; Edmonds, Marie; Bass, Venus A.

    2005-01-01

    The lava dome collapse of 12–13 July 2003 was the largest of the Soufrière Hills Volcano eruption thus far (1995–2005) and the largest recorded in historical times from any volcano; 210 million m3 of dome material collapsed over 18 h and formed large pyroclastic flows, which reached the sea. The evolution of the collapse can be interpreted with reference to the complex structure of the lava dome, which comprised discrete spines and shear lobes and an apron of talus. Progressive slumping of talus for 10 h at the beginning of the collapse generated low-volume pyroclastic flows. It undermined the massive part of the lava dome and eventually prompted catastrophic failure. From 02:00 to 04:40 13 July 2003 large pyroclastic flows were generated; these reached their largest magnitude at 03:35, when the volume flux of material lost from the lava dome probably approached 16 million m3 over two minutes. The high flux of pyroclastic flows into the sea caused a tsunami and a hydrovolcanic explosion with an associated pyroclastic surge, which flowed inland. A vulcanian explosion occurred during or immediately after the largest pyroclastic flows at 03:35 13 July and four further explosions occurred at progressively longer intervals during 13–15 July 2003. The dome collapse lasted approximately 18 h, but 170 of the total 210 million m3 was removed in only 2.6 h during the most intense stage of the collapse.

  16. Silicon isotope fractionation during silica precipitation from hot-spring waters: Evidence from the Geysir geothermal field, Iceland

    Science.gov (United States)

    Geilert, Sonja; Vroon, Pieter Z.; Keller, Nicole S.; Gudbrandsson, Snorri; Stefánsson, Andri; van Bergen, Manfred J.

    2015-09-01

    This study aims to explore the extent and controls of silicon isotope fractionation in hot spring systems of the Geysir geothermal area (Iceland), a setting where sinter deposits are actively formed. The δ30Si values of dissolved silica measured in the spring water and sampling sites along outflowing streams, covering a temperature range between 20 and 100 °C, were relatively constant around +0.2‰, whereas the δ30Si signatures of associated opaline sinters from the streambeds were between -0.1‰ and -4.0‰, becoming progressively more negative in the downstream parts of the aprons. Here, the deposited sinters represent some of the most 30Si depleted abiotically produced terrestrial materials documented to date. Compared to the data reported for Icelandic basalts, considered to be the source of the silicon, the δ30Si values of the fluids and sinter deposits are higher and lower, respectively. The resulting values for apparent solid-water isotope fractionation (Δ30Sisolid-water) decreased with decreasing temperature from ca. -0.7‰ at ∼80 °C to -3.7‰ at ∼20 °C, locally down to -4.4‰. This temperature relationship was reproducible in each of the investigated hot spring systems and is qualitatively consistent with recent findings in laboratory experiments on kinetic fractionation for a flowing fluid. However, the apparent fractionation magnitudes observed in the field are ca. -2‰ more negative and thus significantly larger. We infer that solid-water silicon isotope fractionation during deposition of amorphous silica from a flowing fluid correlates inversely with temperature, but is essentially a function of the precipitation rate, such that the fractionation factor decreases with increasing rate. As an important corollary, the effective fractionation behavior during precipitation of silica from saturated solutions is a system-dependent feature, which should be taken into account when using silicon isotopes for paleo-environmental reconstructions.

  17. Incipient silicification of recent conifer wood at a Yellowstone hot spring

    Science.gov (United States)

    Hellawell, Jo; Ballhaus, Chris; Gee, Carole T.; Mustoe, George E.; Nagel, Thorsten J.; Wirth, Richard; Rethemeyer, Janet; Tomaschek, Frank; Geisler, Thorsten; Greef, Karin; Mansfeldt, Tim

    2015-01-01

    A branch of lodgepole pine (Pinus contorta) from a silica sinter apron of Cistern Spring, Yellowstone National Park, is partially mineralized with silica gel. The distribution of Si mapped in transverse sections of the branch suggests that mineralization was episodic. Early silica-rich solutions used the cellular structures in the wood as pathways, in particular the axial tracheids and rays. Later solutions infiltrated into the branch through shrinkage cracks along the decorticated branch's periphery. Among the tracheids, a distinct preference is noted for silica precipitates to line lumina of the earlywood tracheids, suggesting that this differential concentration in silica may reflect seasonal growth and water uptake in a live tree. Raman spectroscopy identifies the silica phases as amorphous silica gel. Secondary electron images of radial sections along the tracheids demonstrate that the distribution of silica is heterogeneous on a micrometer scale. Silica gel precipitates form micro spheroids with a spherical substructure that extends down to the sub-nanometer scale. All cell walls are templated with a monolayer consisting of closely spaced silica gel nano spheres around 100 nm in diameter. Transmission electron microscopy of focused ion beam sections through cell walls of partially mineralized tracheids reveals that the permineralization of cellular structures and the replacement of organic material by silica are processes that go hand in hand. The branch is dated with the 14C chronometer to 140 ± 33 years, underlining that the silicification reactions that preserve wood in the fossil record can be very rapid. Textural considerations of Si distribution in the wood suggest that the early stages of silicification in this branch date from a time when the pine tree was still alive.

  18. Occupational and patient exposure as well as image quality for full spine examinations with the EOS imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Damet, J., E-mail: jerome.damet@chuv.ch; Fournier, P.; Monnin, P.; Sans-Merce, M.; Verdun, F. R.; Baechler, S. [Institute of Radiation Physics, Lausanne University Hospital, Lausanne 1007 (Switzerland); Ceroni, D. [Department of Paediatrics, Division of paediatric orthopaedic, University Hospitals of Geneva, Geneva 1205 (Switzerland); Zand, T. [Department of Radiology, Division of paediatric radiology, University Hospitals of Geneva, Geneva 1205 (Switzerland)

    2014-06-15

    Purpose: EOS (EOS imaging S.A, Paris, France) is an x-ray imaging system that uses slot-scanning technology in order to optimize the trade-off between image quality and dose. The goal of this study was to characterize the EOS system in terms of occupational exposure, organ doses to patients as well as image quality for full spine examinations. Methods: Occupational exposure was determined by measuring the ambient dose equivalents in the radiological room during a standard full spine examination. The patient dosimetry was performed using anthropomorphic phantoms representing an adolescent and a five-year-old child. The organ doses were measured with thermoluminescent detectors and then used to calculate effective doses. Patient exposure with EOS was then compared to dose levels reported for conventional radiological systems. Image quality was assessed in terms of spatial resolution and different noise contributions to evaluate the detector's performances of the system. The spatial-frequency signal transfer efficiency of the imaging system was quantified by the detective quantum efficiency (DQE). Results: The use of a protective apron when the medical staff or parents have to stand near to the cubicle in the radiological room is recommended. The estimated effective dose to patients undergoing a full spine examination with the EOS system was 290μSv for an adult and 200 μSv for a child. MTF and NPS are nonisotropic, with higher values in the scanning direction; they are in addition energy-dependent, but scanning speed independent. The system was shown to be quantum-limited, with a maximum DQE of 13%. The relevance of the DQE for slot-scanning system has been addressed. Conclusions: As a summary, the estimated effective dose was 290μSv for an adult; the image quality remains comparable to conventional systems.

  19. Knowledge and Practice of Standard Precautions and Awareness Regarding Post-Exposure Prophylaxis for HIV among Interns of a Medical College in West Bengal, India

    Directory of Open Access Journals (Sweden)

    Shuvankar Mukherjee

    2013-03-01

    Full Text Available Objectives: To assess the knowledge of interns on standard precautions and post-exposure prophylaxis for HIV, and identify the gap between knowledge and practice relating to standard precautions, as well as determining the perceived barriers against adherence to standard precautions.Methods: The study was conducted on 130 interns of 2010-11 batch from a government-run medical college in Kolkata, India. All participants completed a self-administered questionnaire with items relating to basic components of standard precautions and post-exposure prophylaxis for HIV. The questionnaire also included open ended questions relating to reasons for non-adherence to the practice of standard precautions along with additional space for specific comments, if any.Results: Poor adherence in the use of personal protective equipment, hand washing, safe handling and disposal of needles and sharp objects were found to be among the practices for which the interns expressed correct knowledge. While the main reasons for non-adherence were found to be clumsiness in handling needles, wearing gloves, feeling uncomfortable when wearing aprons, impracticality of regular hand-washing and non-availability of equipment. Although the majority of the respondents (84.6% expressed awareness of washing sites of injured with soap and water, approximately 32.3% did not know that antiseptics could cause more damage. Also, only 63.8% expressed awareness of reporting any incidence of occupational exposure, while knowledge on post-exposure prophylaxis regimens was generally found to be poor.Conclusion: The considerable gap between knowledge and practice of standard precautions and inadequate knowledge of post-exposure prophylaxis emphasizes the need for continuous onsite training of interns with supportive supervision and monitoring of their activities.

  20. Occupational exposure to ultrafine particles among airport employees--combining personal monitoring and global positioning system.

    Directory of Open Access Journals (Sweden)

    Karina Lauenborg Møller

    Full Text Available BACKGROUND: Exposure to ultrafine particles (UFP has been linked to cardiovascular and lung diseases. Combustion of jet fuel and diesel powered handling equipment emit UFP resulting in potentially high exposure levels among employees working at airports. High levels of UFP have been reported at several airports, especially on the apron, but knowledge on individual exposure profiles among different occupational groups working at an airport is lacking. PURPOSE: The aim of this study was to compare personal exposure to UFP among five different occupational groups working at Copenhagen Airport (CPH. METHOD: 30 employees from five different occupational groups (baggage handlers, catering drivers, cleaning staff and airside and landside security at CPH were instructed to wear a personal monitor of particle number concentration in real time and a GPS device. The measurements were carried out on 8 days distributed over two weeks in October 2012. The overall differences between the groups were assessed using linear mixed model. RESULTS: Data showed significant differences in exposure levels among the groups when adjusted for variation within individuals and for effect of time and date (p<0.01. Baggage handlers were exposed to 7 times higher average concentrations (geometric mean, GM: 37×103 UFP/cm(3, 95% CI: 25-55 × 10(3 UFP/cm(3 than employees mainly working indoors (GM: 5 × 10(3 UFP/cm(3, 95% CI: 2-11 × 103 UFP/cm(3. Furthermore, catering drivers, cleaning staff and airside security were exposed to intermediate concentrations (GM: 12 to 20 × 10(3 UFP/cm(3. CONCLUSION: The study demonstrates a strong gradient of exposure to UFP in ambient air across occupational groups of airport employees.

  1. Tracing Biosignature Preservation of Geothermally Silicified Microbial Textures into the Geological Record.

    Science.gov (United States)

    Campbell, Kathleen A; Lynne, Bridget Y; Handley, Kim M; Jordan, Sacha; Farmer, Jack D; Guido, Diego M; Foucher, Frédéric; Turner, Susan; Perry, Randall S

    2015-10-01

    New Zealand and Argentine (Late Jurassic-Recent) siliceous hot-spring deposits (sinter) reveal preservation pathways of environmentally controlled, microbe-dominated sedimentary facies over geological time scales. Texturally distinctive, laminated to thinly layered, dense and vertically oriented, microtubular "palisade" fabric is common in low-temperature (<40°C) sinter-apron terraces. In modern hot springs, the dark green to brown, sheathed, photosynthetic cyanobacterium Calothrix spp. (family Rivulariaceae) constructs felted palisade mats in shallow terrace(tte) pools actively accreting opaline silica. The resulting stacked layers of silicified coarse filaments-a stromatolite-are highly porous and readily modified by postdepositional environmental perturbations, secondary silica infill, and diagenetic silica phase mineral transformations (opal-A to quartz). Fossil preservation quality is affected by relative timing of silicification, and later environmental and geological events. A systematic approach was used to characterize palisade fabric in sinters of different ages to refine tools for recognizing biosignatures in extreme environments and to track their long-term preservation pathways into the geological record. Molecular techniques, scanning electron microscopy, Raman spectrometry, X-ray powder diffraction, petrography, and lipid biomarker analyses were applied. Results indicate that microbial communities vary at the micron scale and that early and rapid silicification is paramount to long-term preservation, especially where minimal postdepositional disturbance follows fossilization. Overall, it appears that the most robust biomarkers of fossil microbial activity in hot-spring deposits are their characteristic macro- and microtextures and laser micro-Raman identified carbon. Studies of Phanerozoic geothermal deposits with mineralized microbial components are relevant analogs for Precambrian geobiology because early life is commonly preserved as microbial

  2. Role of experience, leadership and individual protection in cath lab. A multicenter questionnaire and workshop on radiation safety

    International Nuclear Information System (INIS)

    Radiation exposure in invasive cardiology remains considerable. We evaluated the acceptance of radiation protective devices and the role of operator experience, team leadership, and technical equipment in radiation safety efforts in the clinical routine. Cardiologists (115 from 27 centers) answered a questionnaire and documented radiation parameters for 10 coronary angiographies (CA), before and 3.1 months after a 90-min. mini-course in radiation-reducing techniques. Mini-course participants achieved significant median decreases in patient dose area products (DAP: from 26.6 to 13.0 Gy x cm2), number of radiographic frames (- 29 %) and runs (- 18 %), radiographic DAP/frame (- 32 %), fluoroscopic DAP/s (- 39 %), and fluoroscopy time (- 16 %). Multilevel analysis revealed lower DAPs with decreasing body mass index (- 1.4 Gy x cm2 per kg/m2), age (- 1.2 Gy x cm2/decade), female sex (- 5.9 Gy x cm2), participation of the team leader (- 9.4 Gy x cm2), the mini-course itself (- 16.1 Gy x cm2), experience (- 0.7 Gy x cm2/1000 CAs throughout the interventionalist's professional life), and use of older catheterization systems (- 6.6 Gy x cm2). Lead protection included apron (100 %), glass sheet (95 %), lengthwise (94 %) and crosswise (69 %) undercouch sheet, collar (89 %), glasses (28 %), cover around the patients' thighs (19 %), foot switch shield (7 %), gloves (3 %), and cap (1 %). Radiation-protection devices are employed less than optimally in the clinical routine. Cardiologists with a great variety of interventional experience profited from our radiation safety workshop - to an even greater extent if the interventional team leader also participated.

  3. Assessment of radiation protection of patients and staff in interventional procedures in four Algerian hospitals.

    Science.gov (United States)

    Khelassi-Toutaoui, N; Toutaoui, A; Merad, A; Sakhri-Brahimi, Z; Baggoura, B; Mansouri, B

    2016-01-01

    This study was aimed to assess patient dosimetry in interventional cardiology (IC) and radiology (IR) and radiation safety of the medical operating staff. For this purpose, four major Algerian hospitals were investigated. The data collected cover radiation protection tools assigned to the operating staff and measured radiation doses to some selected patient populations. The analysis revealed that lead aprons are systematically worn by the staff but not lead eye glasses, and only a single personal monitoring badge is assigned to the operating staff. Measured doses to patients exhibited large variations in the maximum skin dose (MSD) and in the dose area product (DAP). The mean MSD registered values are as follows: 0.20, 0.14 and 1.28 Gy in endoscopic retrograde cholangiopancreatography (ERCP), coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA) procedures, respectively. In PTCA, doses to 3 out of 22 patients (13.6 %) had even reached the threshold value of 2 Gy. The mean DAP recorded values are as follows: 21.6, 60.1 and 126 Gy cm(2) in ERCP, CA and PTCA procedures, respectively. Mean fluoroscopic times are 2.5, 5 and 15 min in ERCP, CA and PTCA procedures, respectively. The correlation between DAP and MSD is fair in CA (r = 0.62) and poor in PTCA (r = 0.28). Fluoroscopic time was moderately correlated with DAP in CA (r = 0.55) and PTCA (r = 0.61) procedures. Local diagnostic reference levels (DRLs) in CA and PTCA procedures have been proposed. In conclusion, this study stresses the need for a continuous patient dose monitoring in interventional procedures with a special emphasis in IC procedures. Common strategies must be undertaken to substantially reduce radiation doses to both patients and medical staff. PMID:25646525

  4. Protection from radiation enteritis by an absorbable polyglycolic acid mesh sling

    International Nuclear Information System (INIS)

    Patients with malignant tumors of the pelvis who cannot be cured surgically often are treated with radiation after surgery. A devastating side effect of this treatment is radiation-associated small bowel injury (RASBI). The purpose of this study was to test the hypothesis that removal of the small bowel from the radiation field would protect it against RASBI. Twenty cebus monkeys underwent low anterior resection. In 10 animals an absorbable polyglycolic acid (PGA) mesh was sewn circumferentially around the interior of the abdominal cavity as a supporting apron, which prevented the small bowel's descent into the pelvis. The other 10 monkeys did not receive the mesh. All animals received 2000 rads by linear acceleration in a single dose. Twenty-four-hour stool fat, serum vitamin B12, and other serum values were obtained during the study. Animals were sacrificed after 1, 2, 3, 6, and 12 months, and the small bowel and rectum were examined histologically in a blind manner. Two monkeys who did not undergo surgery, or exposure to radiation served as controls. At all sacrifice periods, the animals with PGA mesh slings demonstrated normal small bowel function and histologic structure. Animals without mesh slings had abnormal stool and blood values at 1 month, and by 2 months all had died of small bowel necrosis. The animals that received the slings had no evidence of infection or obstruction, and by 6 months all evidence of the mesh was gone. Support of the small bowel out of the pelvis by an absorbable PGA mesh sling protects against RASBI and is without apparent complications

  5. Experimental studies of local scour in the pressurized OCF below a wooden log across the flow

    Indian Academy of Sciences (India)

    Soumen Maji; Prashanth Reddy Hanmaiahgari; Subhasish Dey

    2014-10-01

    The proposed study examined and reviewed the published experimental results related to clear water scour below a cylinder across the flow. It also highlighted the limitations of existing methods for estimating the scour depth below a submerged cylinder. In the present study, experiments were performed for 50% and 75% submergences of a 70 mm diameter cylinder in the free surface flow over a uniform sand bed with $d_{50}\\ =$ 0.98 mm downstream of an apron. Based on the experimental results, an empirical equation was proposed to estimate the amount of gap flow between the cylinder and the bed for an equilibrium scour for a given flow depth and sediment properties. Measured scour profile consisted of a scour hole and immediately followed by a dune. However, no general sediment transport was occurring away from the cylinder due to the undisturbed bed shear stress less than or equal to the critical shear stress required for the sediment entrainment. Different submergence ratios of the cylinder resulted in different longitudinal and vertical extensions of the scour hole and the dune. The maximum equilibrium scour depth occurred when the cylinder is fully submerged in the unidirectional flow with water depth equals to the cylinder diameter. The non-dimensional measured scour profiles were found to be similar. The characteristic lengths of the scour hole and the dune were computed analytically by approximating the measured scour profile by third degree polynomials. The computed non-dimensional scour profiles compared satisfactorily with the measured profiles. It was found that analytical non-dimensional scour profiles were identical for a given diameter of a cylinder with different submergences for the same flow conditions.

  6. Dosimetric studies of the lens of the eye using a new dosimeter - polls in two departments of Interventional Radiology of the autonomous city of Buenos Aires

    International Nuclear Information System (INIS)

    During interventional radiology (IR) and cardiology (IC) procedures, medical staff can receive high doses to their eye lenses. The Retrospective Evaluation of Lens Injuries and Dose (RELID) study organized in Argentina in 2010 found incipient opacity in 50% of IC physicians and 41% of IC technicians/nurses. These results, added to the recommendations of the International Commission on Radiological Protection (ICRP), which lowered their former occupational equivalent dose limit for the lens, led us to assess the eye lens dose, Hp(3), during interventional procedures. To this end, a new dosemeter was designed and calibrated at the National Atomic Energy Commission (CNEA) of Argentina to evaluate Hp(3). Personal dose equivalent (Hp(10)), and Hp(3) were assessed for 3 months in two IC and IR departments of Buenos Aires City using thermoluminescent dosimeters (TLD) and electronic personal dosimeter (EPD). An Rando Alderson phantom was used to simulate monthly exposures of five occupational staff members. Hp(3) and Hp(10) were obtained monthly for 14 occupational staff members exposed to 121 IR and IC procedures. We concluded that the annual effective dose and Hp(3) were lower than 0.3 and 10 mSv, respectively. An occupational annual dose constraint of 0.3 mSv was calculated. Average cumulative Hp(3) for working life of 40 years should be lower than 400 and 200 mSv for physicians and technicians/scrub nurse, respectively. Also we concluded that a calibrated EPD worn on a pocket in the lead apron and a TLD dosemeter worn on the collar thyroid (both at the maximal radiation side) could be used as guidance to the lens dose. Finally, To reduce doses of medical staff, actions should be promoted to maximize radiation protection in interventional procedures with appropriate training, using personal dosimetry and protection instruments as lead glasses, ceiling-suspended shields and others. (author)

  7. Dose levels in medical staff at hemodynamics services in Minas Gerais State, Brazil-Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Junior, Airton T. de [FUNDACENTRO-Brazilian Institute for Safety and Health at Work, Rua Guajajaras, no 40, 14o andar, Centro, 30180-100 Belo Horizonte, Minas Gerais (Brazil); Alonso, Thessa C. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN)-Av. Prof. Antonio Carlos 6627, Campus UFMG, Pampulha, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Nogueira, Maria do S. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN)-Av. Prof. Antonio Carlos 6627, Campus UFMG, Pampulha, 31270-901 Belo Horizonte, Minas Gerais (Brazil)], E-mail: mnogue@edtn.br; Silva, Teogenes A. da [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN)-Av. Prof. Antonio Carlos 6627, Campus UFMG, Pampulha, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2008-02-15

    Medical staff during interventional radiology could be exposed to radiation conditions that may cause very high dose levels depending on the X-ray machine operational conditions. The dose levels received by medical staff during interventional radiology are very high depending on the operational conditions and the patient trunk thickness. Dose levels could reach a factor of 30 for fluoroscopy or cine modes. The ALARA principle, which emphasizes the adoption of techniques and procedures to keep dose levels as low as reasonably achievable, should be followed to minimize the risk of radiation exposure to medical professionals. Dose reduction could be achieved by persuading the medical staff to wear protection devices (lead apron, thyroid protector, eyeglasses and gloves). Additionally, medical staff should also be persuaded that they should not be submitted to very high doses, above the acceptable limits for occupational workers. Dose levels at hemodynamics services in Minas Gerais State, Brazil, were analyzed. Due to the equipment characteristics or the exam type and conditions X-ray machines were used with 70-120 kV, 2.5-699 mA and 80-2880 s. Annual individual doses were estimated based on measured doses during a specific exam taking into account the workload. Maximum doses varied from 0.05 to 0.70 mSv per exam. The results projected for one work-year period show that all annual individual doses would be higher than the annual dose limit of 20 mSv/y with only a few values lower than 50 mSv/y. Dose levels measured at medical staff positions during hemodynamic exams showed that if the protective devices are not used professionals could be exposed to dose values higher than annual dose limits.

  8. Dose levels in medical staff at hemodynamics services

    International Nuclear Information System (INIS)

    The dose levels received by medical staff during interventional radiology are very high depending on the operational conditions and the patient trunk thickness. Dose levels could reach a factor of 30 for fluoroscopy or cine modes. The ALARA principle, that emphasizes the adoption of techniques and procedures to keep dose levels as low as reasonably achievable, should be followed to minimize the risk of radiation exposure to medical professionals. Dose reduction could be achieved by persuading the medical staff to wear protection devices (lead apron, thyroid protector, eyeglasses and gloves). Additionally, medical staff should also be persuaded that they should not be submitted to very high doses, above the acceptable limits for occupational workers. Dose levels at hemodynamics services in Minas Gerais State, Brazil, were analysed. Due to the equipment characteristics or the exam type and conditions x-ray machines were used with 70 to 120 kV, 2.5 to 699 mA and 80 to 2880s. Annual individual doses were estimated based on measured doses during a specific exam taking into account the workload. Maximum doses varied from 0.05 to 0.70 mSv per exam. The results projected for one work-year period show that all annual individual doses would be higher than the annual dose limit of 20 mSv/y with only a few values lower than 50 mSv/y. Dose levels measured at medical staff positions during hemodynamic exams showed that if the protective devices are not used professionals could be exposed to dose values higher than annual dose limits. (author)

  9. Dose levels in medical staff at hemodynamics services

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Junior, Airton T. de [FUNDACENTRO - Brazilian Institute for Safety and Health at Work, Belo Horizonte, MG (Brazil)]|[Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: airton.almeida@fundacentro.gov.br; Alonso, Thessa C.; Nogueira, Maria do S.; Silva, Teogenes A. da [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: mnogue@cdtn.br; alonso@cdtn.br; silvata@cdtn.br

    2007-07-01

    The dose levels received by medical staff during interventional radiology are very high depending on the operational conditions and the patient trunk thickness. Dose levels could reach a factor of 30 for fluoroscopy or cine modes. The ALARA principle, that emphasizes the adoption of techniques and procedures to keep dose levels as low as reasonably achievable, should be followed to minimize the risk of radiation exposure to medical professionals. Dose reduction could be achieved by persuading the medical staff to wear protection devices (lead apron, thyroid protector, eyeglasses and gloves). Additionally, medical staff should also be persuaded that they should not be submitted to very high doses, above the acceptable limits for occupational workers. Dose levels at hemodynamics services in Minas Gerais State, Brazil, were analysed. Due to the equipment characteristics or the exam type and conditions x-ray machines were used with 70 to 120 kV, 2.5 to 699 mA and 80 to 2880s. Annual individual doses were estimated based on measured doses during a specific exam taking into account the workload. Maximum doses varied from 0.05 to 0.70 mSv per exam. The results projected for one work-year period show that all annual individual doses would be higher than the annual dose limit of 20 mSv/y with only a few values lower than 50 mSv/y. Dose levels measured at medical staff positions during hemodynamic exams showed that if the protective devices are not used professionals could be exposed to dose values higher than annual dose limits. (author)

  10. Chondrichthyan egg cases from the south-west Atlantic Ocean.

    Science.gov (United States)

    Mabragaña, E; Figueroa, D E; Scenna, L B; Díaz de Astarloa, J M; Colonello, J H; Delpiani, G

    2011-11-01

    Egg cases of 21 oviparous chondrichthyan species from the south-west Atlantic Ocean are described and compared. The catshark Schroederichthys bivius has a cigar-shaped egg case with curled tendrils only at the posterior end. Egg cases of the elephant fish Callorhinchus callorynchus are spindle-shaped with anterior and posterior tubular extensions and lateral flanges. The skate Amblyraja doellojuradoi presents medium-sized egg cases (71 mm in length) with a lateral keel extending to the first portion of the horns. The endemic skate species of the genus Atlantoraja have medium to large egg cases (69-104 mm in length) and present relatively large posterior horns. Egg cases of the genus Bathyraja have a medium size, 75-98 mm in length, and are characterized by a very similar morphology, a relatively smooth to rough surface case and posterior horns strongly curved inwards. Egg cases of the genera Dipturus and Zearaja are very large, 115-230 mm in length, and have a well-developed posterior apron. Despite the problematical identification of skates at species level, the egg capsules of the endemic genus Psammobatis are easily diagnosed; the capsules are small (25-53 mm in length), those of Psammobatis rutrum being the smallest known to date in the world. Egg cases of Rioraja agassizi have a medium size, 61-68 mm in length, relatively straight sides, a smooth surface and silky attachment fibres placed in the lateral keel next to each horn. Those of the genus Sympterygia are small to medium sized, 51-86 mm in length, and display the thickest lateral keel and the longest posterior horns among the skates of the world. Egg cases can be a useful tool for identifying species and egg-laying areas; therefore, a provisional key for the south-west Atlantic Ocean chondrichthyan capsules is presented. PMID:22026605

  11. Dynamic paleogeography of the Jurassic Andean Basin: pattern of transgression and localisation of main straits through the magmatic arc

    Directory of Open Access Journals (Sweden)

    J-C. Vicente

    2005-03-01

    Full Text Available The paleogeographic evolution of the Jurassic Andean retroarc basin is examined at a global scale for the Central Andes. In this paper, it is called for the striking continuity and lasting of the active volcanic arc. Both direct and indirect sedimentologic evidences allow to locate the western border (insular of the basin and opposite it with the eastern border (cratonic. Emphasis is placed on the volcaniclastic deposits and synsedimentary structures associated with this insular border. It is concluded that the arc magmatic activity has contributed considerably in sediment supply to the basin. Extent and continuity of the arc implies to locate the straits connecting with the Paleopacific. Systematic check of the time of transgressions coupled with sequential facies analysis provides a dynamic outlook of the transgressive process. Sectors with early transgression allow to distinguish two main gulfs of passage through the arc from which waters have progressed lengthwise at the same time northward and southward in a narrow retroarc furrow : the first at latitude of Taltal (25°S, the second at latitude of Curepto (35°S. Both initiated in the upper Triassic and extended during the Hettangian. The evolution as separate basins (Tarapacá and Aconcagua-Neuquén ended by fusion in middle Pliensbachian giving rise to a continuous elongated basin from Chubut to northern Peru. The remarkable continuity and narrowness of the Andean Basin leaves no doubt about its tectonic control. This stems to its geotectonic setting as a typical retroarc basin adjacent to a very active magmatic arc and explains the extreme mobility of its insular margin characterized by a huge volcanoclastic apron with associated debris flows and turbidites.

  12. Preliminary geologic map of the Sleeping Butte volcanic centers

    International Nuclear Information System (INIS)

    The Sleeping Butte volcanic centers comprise two, spatially separate, small-volume (3) basaltic centers. The centers were formed by mildly explosive Strombolian eruptions. The Little Black Peak cone consists of a main scoria cone, two small satellitic scoria mounds, and associated lobate lava flows that vented from sites at the base of the scoria cone. The Hidden Cone center consists of a main scoria cone that developed on the north-facing slope of Sleeping Butte. The center formed during two episodes. The first included the formation of the main scoria cone, and venting of aa lava flows from radial dikes at the northeast base of the cone. The second included eruption of scoria-fall deposits from the summit crater. The ages of the Little Black Peak and the Hidden Cone are estimated to be between 200 to 400 ka based on the whole-rock K-Ar age determinations with large analytical undertainty. This age assignment is consistent with qualitative observations of the degree of soil development and geomorphic degradation of volcanic landforms. The younger episode of the Hidden Cone is inferred to be significantly younger and probably of Late Pleistocene or Holocene age. This is based on the absence of cone slope rilling, the absence of cone-slope apron deposits, and erosional unconformity between the two episodes, the poor horizon- development of soils, and the presence of fall deposits on modern alluvial surfaces. Paleomagnetic data show that the centers record similar but not identical directions of remanent magnetization. Paleomagnetic data have not been obtained for the youngest deposits of the Hidden Cone center. Further geochronology, soils, geomorphic, and petrology studies are planned of the Sleeping Butte volcanic centers 20 refs., 3 figs

  13. Atlantic and indian oceans pollution in africa

    Science.gov (United States)

    Abubakar, Babagana

    Africa is the second largest and most populated continent after Asia. Geographically it is located between the Atlantic and Indian Oceans. Most of the Africa's most populated and industrialized cities are located along the coast of the continent facing the Atlantic and Indian Oceans, example of such cities include Casablanca, Dakar, Accra, Lagos, Luanda and Cape town all facing the Atlantic Ocean and cities like East London, Durban, Maputo, Dar-es-salaam and Mogadishu are all facing the Indian Ocean. As a result of the geographical locations of African Coastal Cities plus increase in their population, industries, sea port operations, petroleum exploration activities, trafficking of toxic wastes and improper waste management culture lead to the incessant increase in the pollution of the two oceans. NATURE OF POLLUTION OF THE ATLANTIC OCEAN i. The petroleum exploration activities going on along the coast of "Gulf of Guinea" region and Angola continuously causes oil spillages in the process of drilling, bunkering and discharging of petroleum products in the Atlantic Ocean. ii. The incessant degreasing of the Sea Ports "Quay Aprons" along the Coastal cities of Lagos, Luanda, Cape Town etc are continuously polluting the Atlantic Ocean with chemicals. iii. Local wastes generated from the houses located in the coastal cities are always finding their ways into the Atlantic Ocean. NATURE OF POLLUTION OF THE INDIAN OCEAN i. Unlike the Atlantic ocean where petroleum is the major pollutant, the Indian Ocean is polluted by Toxic / Radioactive waste suspected to have been coming from the developed nations as reported by the United Nations Environmental Programme after the Tsunami disaster in December 2004 especially along the coast of Somalia. ii. The degreasing of the Quay Aprons at Port Elizabeth, Maputo, Dar-es-Salaam and Mongolism Sea Ports are also another major source polluting the Indian Ocean. PROBLEMS GENERATED AS A RESULT OF THE OCEANS POLLUTION i. Recent report

  14. Estratigrafía, facies y evolución depositacional de la Formación Sauce Grande (Carbonífero Superior: Cuenca Sauce Grande, Sierras Australes, Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    R. R. Andreis

    2003-06-01

    waques (Smw representan flujos de detritos finos y densos transicionales a flujos licuefactos. Las demás areniscas representan acción de oleaje o corrientes (Sr o por acreción frontal en barras transversales o dunas de arena por flujos traccionales (Sp. El comienzo de los procesos depositacionales de la Formación Sauce Grande fue caracterizado por una rápida transgresión en el Carbonífero tardío bajo condiciones de moderada subsidencia (procesos eustáticos. El megaciclo inferior se caracteriza por la sedimentación en un slope apron o debris apron localizado en las cercanías del talud continental, con fuerte agradación y rara progradación y depende del régimen termal de la base de los glaciares africanos de base fría, bajo condiciones de sistema de mar bajo. En el megaciclo medio significa una rápida fase de avance glaciar asociada a somerización isostática y el tope del apron habría sido retrabajado por olas y corrientes, creando una plataforma costa afuera casi emergente. En el megaciclo superior se produce un nuevo ascenso del mar (cortejo de mar alto, asociado al retroceso de los glaciares en el sector sudafricano y produce la transgresión tastubiana que se continúa en la Formación Piedra Azul. La disminucion del aporte se hace visible por la sistemática disminución en el espesor de las facies, una mayor frecuencia de facies Dmm1 y Smw y la interacción de depósitos pelíticos, que fueron depositados en plataformas de baja pendiente donde se han registrado avance y retroceso de los glaciares. Dos glaciohorizontes fueron identificados: el GH1 vinculado al megaciclo medio y el GH2 en el contacto entre las Formaciones Sauce Grande y Piedra Azul.

  15. River diversions, avulsions and captures in the Tortuguero coastal plain

    Science.gov (United States)

    Galve, Jorge Pedro; Alvarado, Guillermo; Pérez Peña, José Vicente; Azañón, José Miguel; Mora, Mauricio; Booth-Rea, Guillermo

    2016-04-01

    The Tortuguero area is a coastal plain that forms part of the North Limón sedimentary basin, the back-arc region of the Caribbean side of Costa Rica. This coastal plain is characterised by an abnormal drainage pattern with river captures, diversions and shifts in channel directions. We are analyzing this anomalous drainage network adopting a classical geomorphological approach combined with geomorphometric techniques. The SRTM DEM at 1 arc-second of resolution (~30 m) from NASA, topographic maps 1:50,000, satellital images and the digital cartography of the drainage network have been used for inventorying the channel pattern anomalies. River segments were categorized according to sinuosity, orientation, slope changes and incision using GIS tools. Initially, anomalies in the analyzed river courses suggested that buried thrust fronts could disrupt their natural pattern. However, we have not identified any evidence to link the activity of buried structures with the disruption of natural drainage. Blind thrusts detected through seismic subsurface exploration in the SE sector of the Tortuguero plain do not seem to produce changes in the sinuosity, orientation, slope and incision of rivers as those observed in the deeply studied tectonically active area of the Po Plain (Italy). The identified river pattern anomalies have been explained due to other alternative causes: (1) the migration of the mouths of Reventazón, Pacuare and Matina rivers is produced by sand sedimentation in the coast because of a successive ridge beach formation. This migration to the SE has the same direction than the main ocean currents those deposited the sand. (2) The anomalous course of Parismina river is most probably conditioned by the fracturation of the dissected volcanic apron of Turrialba volcano. (3) Channel migration and capture of Barbilla river by Matina river can be triggered by the tectonic tilting of the coastal plain towards the SE. The subsidence of the SE sector of the plain was

  16. Radiation practices 1996

    International Nuclear Information System (INIS)

    At the end of 1996, there were 1,762 valid safety licences in Finland for the use of radiation. In addition, there were 2,052 responsible parties for dental x-ray diagnostics. The registry of the Finnish Centre for Radiation and Nuclear Safety listed 13,360 radiation sources and 313 radionuclide laboratories. The import of radioactive substances amounted to 1.14 x 10+16 Bq and export to 7.78 x 10+13 Bq. A total of 4.02 x 10+13 Bq of short-lived radionuclides were produced in Finland. There were 11,842 workers monitored for radiation exposure at 1,352 work sites. Of these employees, 27% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of individual dosimeter readings) was 7.96 manSv in 1996, with nuclear power plant workers accounting for 69% of this total. The annual dosimeter reading of ten medical doctors (radiologists, interventional radiologists and cardiologists) and eight nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of dosimeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 242 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations where unusually high exposure to radiation was an unavoidable part of the task. Report was made of 12 incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Five of these cases occurred in radiotherapy, three in use of a radiation source in industry, three in transport of radiation sources and one in use of solarium appliances. Radiation-contaminated material was found in 17 shipments of scrap. (orig.)

  17. Development and implementation of a quality assurance system in odontological radiology

    Energy Technology Data Exchange (ETDEWEB)

    Yacovenco, A. [CETRE DO BRASIL (Brazil); Tauhata, L. [LNMRI/IRD/CNEN (Brazil); Infantosi, A.F.C. [PEB/COPPE/UFRJ (Brazil)

    2000-05-01

    According to surveys by the Comissao Nacional de Engenharia Nuclear (CNEN), in odontological radiology, it was concluded that more than 80% of the radiological examinations are performed with entrance skin doses greater than 2.5 mGy, that approximately 85% of the dentists sub develop the films and 40% of the equipment present deficiencies in collimation, filtration and other problems. This is a critical situation for the population's quality of life, which requires prompt intervention to improve Odontological Radiology Services (ORS). The main purpose of this work is to elaborate a process of implementation and management of a Quality Assurance Program (QAP) in Odontological Radiology Services using as a pilot area the state of Sao Paulo. The methodology was based on the orientation of the professionals to safely obtain the best image for diagnostic and its interpretation with the available resources. The strategy was based in monitoring exposure (kVp, time, output, consistency) and geometric (collimation, filtration and contrast) parameters. Internal procedures were also considered such as development control, rejection rate analysis, working conditions of the dentists' office as well as the keeping of a register note book. Results indicate that entrance skin doses greater than 2.5 mGy in 84% of the cases reduced to 43%. Collimation, that before implementation of the QAP was greater than 6 cm in 61% of the cases reduced to only 3%. The following aspects were not considered before the implementation of the QAP and after, 100% of them were applied in the dentists' offices: processing, rejection rate, the keeping of a register note book and the posting of a sign with a warning saying that it is obligatory the use of lead apron. The main difficulties which arose from this work were the meetings with the dentists in order to convince them of the importance of the QAP. Motivation of fully compensated by their attachment to the Program. Results show that

  18. Microbial lifestyles that enable survival in lithifying habitats

    Science.gov (United States)

    Hirst, M.; Dossing, L. N.; Tamez, P.; Ziegler, S.; Hanselmann, K.; Sessions, A. L.; Spear, J. R.; Johnson, H.; Berelson, W.; Corsetti, F. A.; Dawson, S.; de la Torre, J. R.; Usc Wrigley Institute, I.

    2010-12-01

    The precipitation of carbonates in the travertine forming Narrow Gauge hot spring in Yellowstone National Park occurs at a rapid rate, whereby microorganisms that colonize the ponds and apron facies are required to overcome lithification. CO2-fixation by autotrophic microorganisms in this cation-rich environment further promotes carbonate encapsulation. Microorganisms that alter their micro-habitat through dissimilative metabolic processes such as H2S and NH4+oxidation, can decrease acid neutralizing capacity (ANCcarb = [HCO3-] + 2[CO32-] + [OH-] - [H+] ) and locally delay CaCO3 mineralization. Genomic and geochemical approaches were combined to study the metabolic processes and microbial populations in a sulfidic hot spring emerging from a carbonate fissure ridge. Samples from locations close to the discharge vent and along its outflow channel were preserved for DNA sequencing, ATP measurements, microscopy, ion chromatographic and ICP-MS analyses of the major solutes and for ANC titration. Temperature, conductivity and pH were measured at the sampling sites. A pyrotagged 16S rRNA gene sequencing approach at both sites was used along with a publicly accessible metagenome of a similar site at the same location. The 16S rRNA gene sequence analyses reveal a great diversity of phylotypes related to species with known physiological potentials. The diversity at the vent is greater and more even than at the cooler site 6m downstream. A number of genes for C-1 fixing enzymes point to the presence of the reductive citric acid cycle, as well as to parts of the reductive acetyl-CoA pathway, the 3-hydroxypropionate cycle and the serine cycle as dominant forms of carbon metabolism. A complete set of genes for all enzymes of the reductive citric acid cycle were found, which indicates a dominance of this pathway for carbon fixation. Surprisingly, genes for RubisCo appear to be absent. Almost all genes found for enzymes that catalyze the conversion of sulfur compounds are involved

  19. Tectonic and sedimentary evolution of a Cretaceous continental arc-backarc system in the Korean peninsula: New view

    Science.gov (United States)

    Chough, S. K.; Sohn, Y. K.

    2010-08-01

    a number of calderas or volcanotectonic depressions. Volcaniclastic aprons fringing the arc platform encroached upon the basin fill. Intraarc basins, produced by sinistral shearing of the arc platform, received sediments from active volcanoes and footwalls of contemporaneous faults, forming small-scale streamflow-dominated alluvial fans and floodplains with later development of a deep lake. Overall, the Gyeongsang Arc System formed under an extensional or transtensional (sinistral strike-slip) stress regime, suggesting that the subducting and the overriding plates were not strongly coupled. Both the volcanic arc and the backarc basin ceased to develop as volcanic activities shifted progressively eastward in the Paleogene accompanied with rollback of the subduction of the Izanagi plate.

  20. 云南省玉米种子带菌检测及种衣剂处理的生物学效应%Testing of Seed Borne Fungi of Major Corn Varieties from Yunnan Province and Effect of Seed Coating Treatment with Different Formulations

    Institute of Scientific and Technical Information of China (English)

    李健强; 刘西莉; 朱春雨; 罗军; 朱建军; 李小林; 浦恩堂; 张松

    2001-01-01

    This study reported the testing of seed borne fungi of major corn varieties from Yunnan province and effect of seed coating treatment with four different formulations by means of petri-dish testing and field experiment.The results showed that Penicillium, Rhizopus, Paecilomyce, and Trichoderma were main seed borne fungi on the surface of 3 major corn variesties from Yunnan province; Helminthosporium, Rhizopus, Fusarium, and Penicillium represented main seed borne fungi inside. Nigrospora, Alternaria, and Phoma were minor seed borne fungi. The fungi on the seed surface and inside expressed significantly difference among experimental varieties. 20% Carbofuran-Thiram seed coating formulation (specific for corn seed coating treatment) provided a good control for seed borne fungi, increased seed germination and seedling emergence. Apron and Celest treatment expressed obvious sound seedling.%采用平皿测定方法和田间小区试验对云南省3个主栽玉米品种分别进行了种子带菌检测和4种不同种衣剂包衣处理的生物学效应研究。结果表明,玉米种子表面携带的优势菌群主要为青霉菌(Penicillium)、根霉菌(Rhizopus)、瓶梗青霉菌(Paecilomyces)和木霉菌(Trichoderma);种子内部寄藏的真菌主要有长蠕孢菌(Helminthosporium)、根霉菌(Rhizopus)、镰刀菌(Fusarium)和青霉菌(Penicillium),其它分离频率较高的寄藏真菌还有黑孢霉菌(Nigrospora)、交链孢菌(Alternaria)和茎点霉菌(Phoma)等;种子表面和内部携带真菌种类在品种之间有较大差异。20%克福种衣剂对种子带菌消毒、提高发芽和出苗率效果显著;Apron和Celest在促进壮苗方面具有良好的作用。

  1. Morphology, volcanism, and mass wasting in Crater Lake, Oregon

    Science.gov (United States)

    Bacon, C.R.; Gardner, J.V.; Mayer, L.A.; Buktenica, M.W.; Dartnell, P.; Ramsey, D.W.; Robinson, J.E.

    2002-01-01

    Crater Lake was surveyed nearly to its shoreline by high-resolution multibeam echo sounding in order to define its geologic history and provide an accurate base map for research and monitoring surveys. The bathymetry and acoustic backscatter reveal the character of landforms and lead to a chronology for the concurrent filling of the lake and volcanism within the ca. 7700 calibrated yr B.P. caldera. The andesitic Wizard Island and central-plattform volcanoes are composed of sequences of lava deltas that record former lake levels and demonstrate simultaneous activity at the two vents. Wizard Island eruptions ceased when the lake was ~80 m lower than at present. Lava streams from prominent channels on the surface of the central platform descended to feed extensive subaqueous flow fields on the caldera floor. The Wizard Island and central-platform volcanoes, andesitic Merriam Cone, and a newly discovered probable lava flow on the eastern floor of the lake apparently date from within a few hundred years of caldera collapse, whereas a small rhydacite dome was emplaced on the flank of Wizard Island at ca. 4800 cal. yr B.P. Bedrock outcrops on the submerged caldera walls are shown in detail and, in some cases, can be correlated with exposed geologic units of Mount Mazama. Fragmental debris making up the walls elsewhere consists of narrow talus cones forming a dendritic pattern that leads to fewer, wider ridges downslope. Hummocky topography and scattered blocks up to ~280 m long below many of the embayments in the caldera wall mark debris-avalanche deposits that probably formed in single events and commonly are affected by secondary failures. The flat-floored, deep basins contain relatively fine-grained sediment transported from the debris aprons by sheet-flow turbidity currents. Crater Lake apparently filled rapidly (ca. 400-750 yr) until reaching a permeable layer above glaciated lava identified by the new survey in the northeast caldera wall at ~1845 m elevation

  2. Occupational Radiation Exposure During Endovascular Aortic Repair

    Energy Technology Data Exchange (ETDEWEB)

    Sailer, Anna M., E-mail: anni.sailer@mumc.nl [Maastricht University Medical Centre (MUMC), Department of Radiology (Netherlands); Schurink, Geert Willem H., E-mail: gwh.schurink@mumc.nl [Maastricht University Medical Centre (MUMC), Department of Surgery (Netherlands); Bol, Martine E., E-mail: m.bol@maastrichtuniversity.nl; Haan, Michiel W. de, E-mail: m.de.haan@mumc.nl; Zwam, Willem H. van, E-mail: w.van.zwam@mumc.nl; Wildberger, Joachim E., E-mail: j.wildberger@mumc.nl; Jeukens, Cécile R. L. P. N., E-mail: cecile.jeukens@mumc.nl [Maastricht University Medical Centre (MUMC), Department of Radiology (Netherlands)

    2015-08-15

    PurposeThe aim of the study was to evaluate the radiation exposure to operating room personnel and to assess determinants for high personal doses during endovascular aortic repair.Materials and MethodsOccupational radiation exposure was prospectively evaluated during 22 infra-renal aortic repair procedures (EVAR), 11 thoracic aortic repair procedures (TEVAR), and 11 fenestrated or branched aortic repair procedures (FEVAR). Real-time over-lead dosimeters attached to the left breast pocket measured personal doses for the first operators (FO) and second operators (SO), radiology technicians (RT), scrub nurses (SN), anesthesiologists (AN), and non-sterile nurses (NSN). Besides protective apron and thyroid collar, no additional radiation shielding was used. Procedural dose area product (DAP), iodinated contrast volume, fluoroscopy time, patient’s body weight, and C-arm angulation were documented.ResultsAverage procedural FO dose was significantly higher during FEVAR (0.34 ± 0.28 mSv) compared to EVAR (0.11 ± 0.21 mSv) and TEVAR (0.06 ± 0.05 mSv; p = 0.003). Average personnel doses were 0.17 ± 0.21 mSv (FO), 0.042 ± 0.045 mSv (SO), 0.019 ± 0.042 mSv (RT), 0.017 ± 0.031 mSv (SN), 0.006 ± 0.007 mSv (AN), and 0.004 ± 0.009 mSv (NSN). SO and AN doses were strongly correlated with FO dose (p = 0.003 and p < 0.001). There was a significant correlation between FO dose and procedural DAP (R = 0.69, p < 0.001), iodinated contrast volume (R = 0.67, p < 0.001) and left-anterior C-arm projections >60° (p = 0.02), and a weak correlation with fluoroscopy time (R = 0.40, p = 0.049).ConclusionAverage FO dose was a factor four higher than SO dose. Predictors for high personal doses are procedural DAP, iodinated contrast volume, and left-anterior C-arm projections greater than 60°.

  3. JURASSIC PALAEOGEOGRAPHY OF THE TRANSDANUBIAN CENTRAL RANGE (HUNGARY

    Directory of Open Access Journals (Sweden)

    ATTILA VÖRÖS

    1998-03-01

    Full Text Available The Transdanubian Central Range (TCR is a flattened range of hills in northern Transdanubia (Hungary, formed mainly by Mesozoic carbonate rocks showing strong facies similarities with the Southern Alps and the Austroalpine domain. The Jurassic system is divided into several formations of predominantly pelagic limestones. Ammonoids are frequent and were collected bed-by-bed in numerous sections, providing an excellent biostratigraphic resolution. The thickness of the Jurassic system is usually small but changes along the strike of the TCR. It reaches a maximum thickness of 500 m in the western part; is very variable (10-400 m in the central segment (Bakony Mts. and rather low (less than 100 m in the east (Gerecse. In the Bakony segment, the thickness variation reflects the strongly dissected topography of the Jurassic sea-floor. Synsedimentary tectonics is dominated by normal faults; tilted blocks and listric faults may be inferred only in the east.Five main steps were identified in the palaeogeographic evolution: 1 Late Hettangian: carbonate oolitic shoals prevail, except for a few sites where non-deposition or neritic sediments occur. 2 Sinemurian and Pliensbachian: tectonic disintegration resulted in an intricate pattern of submarine horsts and intervening basins, with condensed sedimentation or non-deposition on the horsts and thicker, continuous sedimentary sequences in the basins. The submarine topographic highs are surrounded by aprons of redeposited material (scarp breccias, brachiopod coquinas, crinoidal calcarenites, spiculitic cherty limestones, while pure or argillaceous limestones (Rosso Ammonitico prevail in the distal areas. 3 Early Toarcian: the Tethys-wide anoxic event is superimposed on the previous submarine bottom topography; the resulting black shales and sedimentary Mn-ores are concentrated on the western sides of some horsts. 4 Dogger to Early Malm: radiolarites with heterochronous lower and upper boundaries (Aalenian to

  4. An ichnofabric approach to the depositional interpretation of the intensely burrowed Bateig Limestone, Miocene, SE Spain

    Science.gov (United States)

    de Gibert, Jordi M.; Goldring, Roland

    2007-01-01

    The foraminiferal-rich pelagic Bateig Limestone forms several varieties of the important building stones quarried at Bateig Hill in southeastern Spain. Three principal ichnofabrics ( Bichordites, mottled- Palaeophycus and mottled- Ophiomorpha) are recognized, which are present in at least two (possibly up to four) repeated successions (cycles). Each succession begins with an erosional event. The Bichordites ichnofabric represents a new type of facies, formed as thin turbidity/grain flow, stratiform units derived from sediment slips off a fault into deep water. Each slipped unit became almost completely bioturbated by infaunal echinoids, colonizing by lateral migration. Because of the thinness of the units, successive colonizations tended to truncate the underlying burrows giving rise to a pseudo-stratification. As the Bichordites ichnofabric accumulated on the fault apron, thus reducing the effective height of the fault scarp, the substrate gradually came under the influence of currents traversing the shelf. This led to a change in hydraulic regime, and to the mottled- Palaeophycus and mottled- Ophiomorpha ichnofabrics in sediment deposited under bed load transport, and associated with laminar and cross-stratified beds and local muddy intervals. Reactivation of the fault triggered erosion and channeling and a return to grain flow sedimentation, and to the Bichordites ichnofabric of the succeeding cycle. The highest unit of the Bateig Limestone is formed entirely of cross-stratified calcarenites with occasional Ophiomorpha ( Ophiomorpha-primary lamination ichnofabric) and is similar to many shallow marine facies but they still bear a significant content of pelagic foraminifera. The sedimentary setting bears resemblance with that described for the Pleistocene Monte Torre Paleostrait and the modern Strait of Messina (Italy), where the narrow morphology of the depositional area enhanced tidal currents and allowed for high-energy sandy deposition in relatively deep

  5. Factors controlling late Cenozoic continental margin growth from the Ebro Delta to the western Mediterranean deep sea

    Science.gov (United States)

    Nelson, C.H.; Maldonado, A.

    1990-01-01

    The Ebro continental margin sedimentation system originated with a Messinian fluvial system. This system eroded both a major subaerial canyon cutting the margin southeastward from the present Ebro Delta and an axial valley that drained northeastward down Valencia Trough. Post-Messinian submergence of this topography and the Pliocene regime of high sea levels resulted in a marine hemipelagic drape over the margin. Late Pliocene to Pleistocene glacial climatic cycles, drainagebasin deforestation, and sea-level lowstands combined to increase sediment supply, cause the margin to prograde, and create a regime of lowstand sediment-gravity flows in the deeper margin. The depositional patterns of regressive, transgressive and highstand sea-level regimes suggest that location of the sediment source near the present Ebro Delta throughout the late Cenozoic, southward current advection of sediment, and greater subsidence in the southern margin combined to cause generally asymmetric progradation of the margin to the southeast. Thicker, less stable deposits filling the Messinian subaerial canyon underwent multiple retrograde failures, eroded wide gullied canyons and formed unchanneled base-of-slope sediment aprons in the central margin area; other margin areas to the north and south developed a series of channel-levee complexes. On the basin floor, the formation of Valencia Valley over the Messinian subaerial valley and earlier faults led to draining of about 20% of the Ebro Pleistocene sediment from channel-levee complexes through the valley to prograde Valencia Fan as much as 500 km northeast of the margin. Thus, the Ebro margin has two growth directions, mainly southeastward during higher sea levels, and eastward to northeastward during lower sea levels. The northeastward draining of turbidity currents has produced unusually thin and widely dispersed turbidite systems compared to those on ponded basin floors. During the past few centuries, man's impact has exceeded natural

  6. Multiple edifice-collapse events in the Eastern Mexican Volcanic Belt: The role of sloping substrate and implications for hazard assessment

    Science.gov (United States)

    Carrasco-Núñez, Gerardo; Díaz-Castellón, Rodolfo; Siebert, Lee; Hubbard, Bernard; Sheridan, Michael F.; Rodríguez, Sergio Raúl

    2006-11-01

    The Citlaltépetl-Cofre de Perote volcanic chain forms an important physiographic barrier that separates the Central Altiplano (2500 masl) from the Gulf Coastal Plain (GCP) (1300 masl). The abrupt eastward drop in relief between these provinces gives rise to unstable conditions and consequent gravitational collapse of large volcanic edifices built at the edge of the Altiplano. Eastward sloping substrate, caused by the irregular configuration of the basement rocks, is the dominant factor that controls the direction of collapsing sectors in all major volcanoes in the region to be preferentially towards the GCP. These collapses produced voluminous debris avalanches and lahars that inundated the well-developed drainages and clastic aprons that characterize the Coastal Plain. Large catastrophic collapses from Citlaltépetl, Las Cumbres, and Cofre de Perote volcanoes are well documented in the geologic record. Some of the avalanches and transformed flows have exceptionally long runouts and reach the Gulf of Mexico traveling more than 120 km from their source. So far, no direct evidence has been found for magmatic activity associated with the initiation of these catastrophic flank-collapses. Apparently, instability of the volcanic edifices has been strongly favored by very intense hydrothermal alteration, abrupt topographic change, and intense fracturing. In addition to the eastward slope of the substrate, the reactivation of pre-volcanic basement structures during the Late Tertiary, and the E-W to ENE-SSW oriented regional stress regimes may have played an important role in the preferential movement direction of the avalanches and flows. In addition to magmatic-hydrothermal processes, high amounts of rainfall in the area is another factor that enhances alteration and eventually weakens the rocks. It is very likely that seismic activity may be the principal triggering mechanism that caused the flank collapse of large volcanic edifices in the Eastern Mexican Volcanic Belt

  7. Pilot study of the dose in crystalline lens in the interventional radiology practice; Estudio piloto de la dosis en cristalino en la practica de radiologia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Castro, A.; Martinez, A.; Fernandez, A.; Molina, D. [Centro de Proteccion e Higiene de las Radiaciones, Carretera de la Cantera, Victoria II, Km. 21.5 Guanabacoa, La Habana (Cuba); Sanchez, L.; Diaz, A., E-mail: ailza@cphr.edu.cu [Hospital Clinico Quirurgico Hermanos Ameijeiras, San Lazaro 701, Centro Habana, La Habana (Cuba)

    2014-08-15

    The interventional radiology involves considerable exposure levels for the occupationally exposed personnel (OEP). The doses can encompass a wide range of values in dependence of the function that develops the personnel and the complexity of each procedure. In organs like the crystalline lens and skin values can be reached that imply the appearance of deterministic effects if is not fulfilled the appropriate measures of radiological protection. This has been demonstrated through multiple studies, among those that the retrospective study of damages in the crystalline lens and dose has been one of those most commented, known as RELID. The objective of that study was to examine the opacity prevalence in the crystalline lens in workers linked to the interventional cardiology and to correlate it with the occupational exposition. The obtained results contributed to that the ICRP recommend a new limit value of equivalent dose for crystalline lens of 20 mSv in one year. With the objective of analyzing the operational implications, in the radiological surveillance programs that they could originate with the new recommendations was developed a pilot study to evaluate the dose in crystalline lens in the OEP linked to the interventional radiology in a Cuban hospital. For this, an anthropomorphic mannequin RANDO-ALDERSON was used on which thermoluminescent dosimeters were placed below and above of the leaded apron and in different positions at level of the crystalline lens: above, below and to the sides of the leaded lenses that the personnel uses routinely. The mannequin was located on the same positions that occupy the main specialist that execute the procedure, as well as of the nurse to assist him. The measurements were made simulating the more representative procedures about complexity, duration time and exposure rate. The used dosimeters were RADOS model for whole body composed of two thermoluminescent detectors Gr-200 (LiF: Mg, Cu, P) to evaluate personal equivalent dose

  8. Eruption style and petrology of a new carbonatitic suite from the Mt. Vulture Southern Italy/: The Monticchio Lakes Formation

    Science.gov (United States)

    Stoppa, Francesco; Principe, Claudia

    1997-09-01

    The Monticchio Lakes Formation MLF is a newly identified carbonatite-melilitite tuff sequence which is exposed in the southwestern sector of the Vulture volcano. It is the youngest example ca. 0.13 m.y. of this type of volcanism in Italy, although other carbonatites of smaller volume, but with similar characteristics, have been discovered recently. This volcanic event occurred in isolation after a 0.35 m.y. period of inactivity at Vulture. The eruption produced two maar-type vents and formed tuff aprons mainly composed of dune beds of lapilli. Depositional features suggest that a dry surge mechanism, possibly triggered by CO 2 expansion, was dominant during tuff emplacement. The MLF event involved a mixture of carbonatite and melilitite liquids which were physically separated before the eruption. Abundant mantle xenoliths are direct evidence of the deep-seated origin of the parental magma and its high velocity of propagation towards the surface. Often, these nodules form the core of lapilli composed of concentric shells of melilitite andror porphyritic carbonatite. Coarse-ash beds alternate with lapilli beds and consist of abundant lumps and spherulae of very fine-grained calcite immersed in a welded, highly compacted carbonatite matrix. Porphyritic carbonatite shells of the lapilli and fine-grained spherulae of calcite in the tuff matrix suggest incipient crystallisation of a carbonatite liquid in subvolcanic conditions and eruption of carbonatite-spray droplets. Dark coloured juvenile fragments mainly consist of melilite, phlogopite, calcite, apatite, perovskite, and häuyne crystals in a carbonatite or melilitite matrix. The rocks have an extremely primitive, ultramafic composition with very high Mga) 85. and Cr and Ni content 1500 ppm-. The calcite contains high SrO, BaO and REE of up to 1.5 wt.%. Similar compositions are typical of primary, magmatic carbonates which are found in both intrusive and extrusive carbonatites. The high modal Sr-Ba-REE-rich calcite

  9. Erratum to ``Eruption style and petrology of a new carbonatitic suite from the Mt. Vulture (Southern Italy): The Monticchio Lakes Formation'' [Journal of Volcanology and Geothermal Research 78 (1997) 251 265

    Science.gov (United States)

    Stoppa, Francesco; Principe, Claudia

    1998-01-01

    The Monticchio Lakes Formation (MLF) is a newly identified carbonatite-melilitite tuff sequence which is exposed in the southwestern sector of the Vulture volcano. It is the youngest example (ca. 0.13 m.y.) of this type of volcanism in Italy, although other carbonatites of smaller volume, but with similar characteristics, have been discovered recently. This volcanic event occurred in isolation after a 0.35 m.y. period of inactivity at Vulture. The eruption produced two maar-type vents and formed tuff aprons mainly composed of dune beds of lapilli. Depositional features suggest that a dry surge mechanism, possibly triggered by CO 2 expansion, was dominant during tuff emplacement. The MLF event involved a mixture of carbonatite and melilitite liquids which were physically separated before the eruption. Abundant mantle xenoliths are direct evidence of the deep-seated origin of the parental magma and its high velocity of propagation towards the surface. Often, these nodules form the core of lapilli composed of concentric shells of melilitite and/or porphyritic carbonatite. Coarse-ash beds alternate with lapilli beds and consist of abundant lumps and spherulae of very fine-grained calcite immersed in a welded, highly compacted carbonatite matrix. Porphyritic carbonatite shells of the lapilli and fine-grained spherulae of calcite in the tuff matrix suggest incipient crystallisation of a carbonatite liquid in subvolcanic conditions and eruption of carbonatite-spray droplets. Dark coloured juvenile fragments mainly consist of melilite, phlogopite, calcite, apatite, perovskite, and häuyne crystals in a carbonatite or melilitite matrix. The rocks have an extremely primitive, ultramafic composition with very high Mg# (> 85) and Cr and Ni content (1500 ppm). The calcite contains high SrO, BaO and REE of up to 1.5 wt.%. Similar compositions are typical of primary, magmatic carbonates which are found in both intrusive and extrusive carbonatites. The high modal Sr

  10. Termite Damage to Buildings: Nature of Attacks and Preventive Construction Methods

    Directory of Open Access Journals (Sweden)

    Abdel E. Ghaly

    2011-01-01

    buildings multiple approaches must be used. Before construction begins all nests and palatable wood must be cleared from the site. Once clearing is completed and before construction begins, wood should be selected based on its natural repellency. If no naturally repellent timber is available wood should be impregnated with a chemical preservative. A chemical barrier must be created by treating all exposed wood in the structure with termiticides and all wood should be placed above a concrete footing. Once materials have been selected additional constructional preventative measures consisting of internal preventive measures within the plinth and external preventive measure in form of concrete grooves and interlocking apron floors around the periphery building should be put in place. Educational and promotional activities will further lead to prevention of termite attack to buildings.

  11. Pilot study of the dose in crystalline lens in the interventional radiology practice

    International Nuclear Information System (INIS)

    The interventional radiology involves considerable exposure levels for the occupationally exposed personnel (OEP). The doses can encompass a wide range of values in dependence of the function that develops the personnel and the complexity of each procedure. In organs like the crystalline lens and skin values can be reached that imply the appearance of deterministic effects if is not fulfilled the appropriate measures of radiological protection. This has been demonstrated through multiple studies, among those that the retrospective study of damages in the crystalline lens and dose has been one of those most commented, known as RELID. The objective of that study was to examine the opacity prevalence in the crystalline lens in workers linked to the interventional cardiology and to correlate it with the occupational exposition. The obtained results contributed to that the ICRP recommend a new limit value of equivalent dose for crystalline lens of 20 mSv in one year. With the objective of analyzing the operational implications, in the radiological surveillance programs that they could originate with the new recommendations was developed a pilot study to evaluate the dose in crystalline lens in the OEP linked to the interventional radiology in a Cuban hospital. For this, an anthropomorphic mannequin RANDO-ALDERSON was used on which thermoluminescent dosimeters were placed below and above of the leaded apron and in different positions at level of the crystalline lens: above, below and to the sides of the leaded lenses that the personnel uses routinely. The mannequin was located on the same positions that occupy the main specialist that execute the procedure, as well as of the nurse to assist him. The measurements were made simulating the more representative procedures about complexity, duration time and exposure rate. The used dosimeters were RADOS model for whole body composed of two thermoluminescent detectors Gr-200 (LiF: Mg, Cu, P) to evaluate personal equivalent dose

  12. Epithermal paleosurfaces

    Science.gov (United States)

    Sillitoe, Richard H.

    2015-10-01

    Many active volcanic-hydrothermal and geothermal systems are characterized by distinctive surface and near-surface landforms and products, which are generated during discharge of a spectrum of fluid types under varied conditions. Remnants of most of these products are preserved in some of their less-eroded, extinct equivalents: epithermal deposits of high-sulfidation (HS), intermediate-sulfidation (IS), and low-sulfidation (LS) types. Steam-heated alteration occupying vadose zones and any underlying silicified horizons formed at paleogroundwater tables characterize HS, IS, and LS deposits as do hydrothermal eruption craters and their subaerial or shallow sub-lacustrine breccia aprons and laminated infill. Although rarely recognized, HS, IS, and LS systems can also contain finely laminated, amorphous silica sediments that accumulated in acidic lakes and mud pots and, exclusive to HS systems, in hyperacidic crater lakes. In contrast, silica sinter and more distal carbonate travertine are hot spring discharge products confined mainly to LS and IS settings, as both form from near-neutral-pH liquids. Hydrothermal chert deposition and sediment silicification can take place in shallow, lacustrine rift settings, also largely restricted to LS and IS deposits. These surface and near-surface hydrothermal products are typically metal deficient, although mercury concentrations are relatively commonplace and were formerly exploited in places. Nonetheless, sinters, hydrothermal eruption craters, and silicified lacustrine sediments may contain anomalously high precious metal values; indeed, the last of these locally constitutes low-grade, bulk-tonnage orebodies. The dynamic nature of epithermal paleosurfaces, caused by either syn-hydrothermal aggradation or degradation, can profoundly affect deposit evolution, leading to either eventual burial or telescoping of shallower over deeper alteration ± precious metal mineralization. Formational age, tectonic and climatic regime

  13. Radiation exposure evaluation of the professional working interventionist procedures in a hemodynamics service

    International Nuclear Information System (INIS)

    An evaluation of the dose distribution received by all the workers involved on coronary angioplasty, arteriography, coronary angiography and mitral valvuloplasty procedures has been made in this work. For the measurements, LiF:Mg, Ti TLD(TLD 100) was used, located in seven different points on the worker's body: hands, knees, neck, forehead and thorax, inside and outside lead apron.) The measurements have been done for each hemo dynamical procedure, and the TLD calibrated in personal dose equivalent (Hp(d)) operational quantity for 0,07 mm, 3 mm and 10 mm depth. Nurses and auxiliary doctors did not receive expressive dose values, indicating that the adopted radioprotection procedures seem to be appropriate and sufficient for them. However, the same is not true for the doctors direct in charge of the procedure. The results show the importance of the use of thyroid protections in these cases. This work discusses the main factors that cause occupational dose increase. From all interventionist hemo dynamical procedures analyzed, the dose values received by the doctors on coronary angioplasty procedures and coronary angiography were higher than the ones found on arteriography and mitral valvuloplasty. The higher dose values has been found for coronary angiography procedures in X-ray tools, that work with fluoroscopy on continuous mode and have been executed with brachial way, even in the eyes, hands, knees and thyroid, with or without shield. Multiplying these high dose values, measured in one procedure by the mean number of annual procedures made at the studied hospital by each doctor, the individual dose annual limits can be surpassed. Based on these estimations, some optimizations suggestions have been made and one discussion about the need of additional monitoring points is presented. Different algorithms have been used in order to estimate the effective dose, including a new proposal. The obtained results using the actual Radiodiagnostic Brazilian regulation

  14. Results of questionnaire to members of Japanese college of radiology. Their attitude and act for medical exposure

    International Nuclear Information System (INIS)

    protective lead apron and used other protection devices like screen at fluoroscopy. Thus most of radiological expert doctors aware of exposure take care of patients and themselves at their daily practice. (T.T.)

  15. Fluoroscopically Guided Percutaneous Vertebroplasty: Assessment of Radiation Doses and Implementation of Procedural Routines to Reduce Operator Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Wrangel, A. von; Cederblad, Aa. (Dept. of Medical Physics and Biomedical Engineering, Sahlgrenska Univ. Hospital, Goeteborg (Sweden)); Rodriguez-Catarino, M. (Dept. of Radiology, Sahlgrenska Univ. Hospital, Goeteborg (Sweden))

    2009-06-15

    Background: Percutaneous vertebroplasty (PVP) is a fluoroscopically guided procedure for the treatment of painful vertebral compression fractures and metastases. Routine legal personal dosimetry repeatedly showed dosimeter doses exceeding 1 mSv/month for the only radiologist performing PVP at our hospital. Based on the nature of the procedure, this raised concern about potentially high doses to the eyes and fingers. Purpose: To assess radiation doses to the operator, and to evaluate possibilities for dose reduction. Material and Methods: Measurements of scattered radiation in simulated thoracic and lumbar PVP procedures were performed using two anatomical phantoms - thorax and lower trunk - and a radiation survey meter. The standard position of the operator was determined as being 50 cm from the irradiated area of the phantom. The protection ability of lead-free gloves was evaluated during the simulations. Operator doses to fingers and eyes during 10 clinical PVP procedures performed by a single operator were measured, and the annual dose was calculated. Routine personal dosimetry was performed using thermoluminescent dosimeter (TLD) badges beneath the lead apron, and doses to fingers and eyes were measured with small TLD tablets. Results: During simulations, the measured operator dose rate arising from lateral fluoroscopy at the thorax and lumbar level was reduced by a factor of 4-5 when the X-ray tube was moved from the operator's side of the patient to the opposite side. Wearing protective gloves reduced radiation dose to the hands by 30-40%. The mean doses arising from the 10 clinical PVP procedures to the right and left hands, using protection gloves, were 2.0 mSv and 4.8 mSv, respectively. The mean dose to the eyes was 0.23 mSv. The mean effective dose to the patients was 12 mSv. Conclusion: Placing the X-ray tube on the side of the patient opposite to the operator and the use of radiation protection gloves significantly reduces radiation exposure to the

  16. Staff extremity doses in interventional radiology. Results of the ORAMED measurement campaign

    International Nuclear Information System (INIS)

    The introduction of interventional radiology (IR) procedures in the 20th century has demonstrated significant advantages over surgery procedures. As a result, their number is continuously rising in diagnostic, as well as, in therapy field and is connected with progress in highly sophisticated equipment used for these purposes. Nowadays, in the European countries more than 400 fluoroscopically guided IR procedures were identified with a 10–12% increase in the number of IR examinations every year (). Depending on the complexity of the different types of the interventions large differences in the radiation doses of the staff are observed. The staff that carries out IR procedures is likely to receive relatively high radiation doses, because IR procedures require the operator to remain close to the patient and close to the primary radiation beam. In spite of the fact that the operator is shielded by protective apron, the hands, eyes and legs remain practically unshielded. For this reason, one of the aims of the ORAMED project was to provide a set of standardized data on extremity doses for the personnel that are involved in IR procedures and to optimize their protection by evaluating the various factors that affect the doses. In the framework of work package 1 of the ORAMED project the impact of protective equipment, tube configuration and access routes were analyzed for the selected IR procedures. The position of maximum dose measured is also investigated. The results of the extremity doses in IR workplaces are presented in this study together with the influence of the above mentioned parameters on the doses. -- Highlights: ► We present a set of data on extremity doses for staff in selected interventional radiology procedures. ► We studied the influence of different parameters. ► The measured doses are analyzed according to the operators skill,his position during work, tube configuration, etc. ► Maximum doses recorded for all types of embolisation, in all

  17. A Description of Sub-Equatorial Volcanic Structures Consistent with Sub-Ice Magmatism East of Nepenthes Mensae, Mars.

    Science.gov (United States)

    Caprarelli, G.; de Pablo Hernandez, M. A.

    2014-12-01

    The Martian region located immediately north of the dichotomy scarp, between latitudes 120°E and 135°E, is covered by fretted terrains, characterised by the presence of knobs and mesas formed by eroded and reworked material of highlands provenance, and the smoother terrains between them [1]. Topographic depressions of oblong shape, generally parallel to the scarp, of rough and chaotic appearance, are also observed. The high resolution (~ 6 m/pixel, [2]) Context Camera (CTX) on board Mars Reconnaissance Orbiter (MRO) makes it possible to examine the morphologies of these topographic depressions in great detail, unveiling their complex geological histories. Here we expand on our earlier work in the adjacent Nepenthes Mensae region [3] and present the results of our observations of morphologies of likely igneous origin. We identified a variety of shapes consistent with magmatic structures and constructs: dikes, collapsed lava tubes, and lava flows are observable in the smoother terrains. Most of the elevated structures in the areas are strongly eroded knobs and mesas covered by dust and debris. In some cases however, the morphological characteristics of 2-10 km-size structures are clear and sharp, which allowed us to identify features consistent with sub-ice volcanic constructs, such as tuyas and tindars [4]. Geological reconstructions involving magma-ice interaction are supported by the presence of lobate aprons around knobs and mesas, and of scalloped ejecta surrounding complex impact craters, suggesting the existence of ice both underground and on the surface of these low elevation areas at the time of formation of these constructs. [1] Tanaka et al. (2005) Geologic Map of the Northern Plains of Mars. USGS SIM 2888. [2] Malin et al. (2007) Context Camera investigation on board the Mars Reconnaissance Orbiter. JGR 112, E05S04, 10.1029/2006JE002808. [3] dePablo and Caprarelli (2010) Possible subglacial volcanoes in Nepenthes Mensae, eastern hemisphere, Mars. LPSC

  18. Radiation exposure evaluation of the professional working interventionist procedures in a hemodynamics service; Avaliacao da exposicao a radiacao dos profissionais que executam procedimentos intervencionistas em um servico de hemodinamica

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, Leonardo Peres

    2004-07-01

    An evaluation of the dose distribution received by all the workers involved on coronary angioplasty, arteriography, coronary angiography and mitral valvuloplasty procedures has been made in this work. For the measurements, LiF:Mg, Ti TLD(TLD 100) was used, located in seven different points on the worker's body: hands, knees, neck, forehead and thorax, inside and outside lead apron.) The measurements have been done for each hemo dynamical procedure, and the TLD calibrated in personal dose equivalent (H{sub p}(d)) operational quantity for 0,07 mm, 3 mm and 10 mm depth. Nurses and auxiliary doctors did not receive expressive dose values, indicating that the adopted radioprotection procedures seem to be appropriate and sufficient for them. However, the same is not true for the doctors direct in charge of the procedure. The results show the importance of the use of thyroid protections in these cases. This work discusses the main factors that cause occupational dose increase. From all interventionist hemo dynamical procedures analyzed, the dose values received by the doctors on coronary angioplasty procedures and coronary angiography were higher than the ones found on arteriography and mitral valvuloplasty. The higher dose values has been found for coronary angiography procedures in X-ray tools, that work with fluoroscopy on continuous mode and have been executed with brachial way, even in the eyes, hands, knees and thyroid, with or without shield. Multiplying these high dose values, measured in one procedure by the mean number of annual procedures made at the studied hospital by each doctor, the individual dose annual limits can be surpassed. Based on these estimations, some optimizations suggestions have been made and one discussion about the need of additional monitoring points is presented. Different algorithms have been used in order to estimate the effective dose, including a new proposal. The obtained results using the actual Radiodiagnostic Brazilian

  19. Intraoral radiology in general dental practices. A comparison of digital and film-based X-ray systems with regard to radiation protection and dose reduction

    International Nuclear Information System (INIS)

    Purpose: The purpose of this study was to gain insight into the distribution and application of digital intraoral radiographic techniques within general dental practices and to compare these with film-based systems in terms of patient dose reduction. Materials and Methods: 1100 questionnaires were handed out to general dental practitioners. Data was analyzed with respect to the type of system by using descriptive statistics and nonparametric tests, i.e. Kruskal-Wallis, Mann-Whitney and chi-square test (SPSS 20). Results: 64% of the questioned dentists still use film-based radiology, 23% utilize storage phosphor plate (SPP) systems and 13% use a charge-coupled device (CCD). A strong correlation between the number of dentists working in a practice and the use of digital dental imaging was observed. Almost 3/4 of the film users work with E- or F-speed film. 45% of them refuse to change to a digital system. The use of lead aprons was popular, while only a minority preferred thyroid shields and rectangular collimators. A fourfold reduction of exposure time from D-speed film to CCD systems was observed. Due to detector size and positioning errors, users of CCD systems take significantly more single-tooth radiographs in total. Considering the number of radiographs per patient, there is only a slight tendency towards more X-rays with CCD systems. Up to image generation, digital systems seem to be as or even more difficult to handle than film-based systems, while their handling was favored after radiographic exposure. Conclusion: Despite a slight increase of radiographs taken with CCD systems, there is a significant dosage reduction. Corresponding to the decrease in exposure time, the patient dose for SPP systems is reduced to one half compared to film. The main issues in CCD technology are positioning errors and the size of the X-ray detectors which are difficult to eliminate. The usage of radiation protection measures still needs to be improved. (orig.)

  20. Radiation practices 1997

    Energy Technology Data Exchange (ETDEWEB)

    Havukainen, R. [ed.

    1998-05-01

    At the end of 1997, there were 1,753 valid safety licenses in Finland for the use of radiation. In addition, there were 2,065 responsible parties for dental x-ray diagnostics. The registry of STUK - Radiation and Nuclear Safety Authority listed 13,839 radiation sources and 302 radionuclide laboratories. The import of radioactive substances amounted to 1.09 x 10{sup +16} Bq and export to 2.4 x 10{sup +13} Bq. Short-lived radionuclides produced in Finland amounted to 5.2 x 10{sup +13} Bq. There were 11,773 workers monitored for radiation exposure at 1,316 work sites. Of these employees, 24% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of the individual dosemeter readings) was 6.6 Sv in 1997, with nuclear power plant workers accounting for 62% of this total. The annual dosemeter reading of thirteen medical doctors (radiologists, interventional radiologists and cardiologists) and six nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of the dosemeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 253 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations in which unusually high exposure to radiation was an unavoidable part of the task. Reports were made of four incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Two of these cases occurred in the medical use of radiation, one in the use of radiation sources in industry, and one in the use of solarium appliances. (orig.)

  1. Radiation practices 1996

    Energy Technology Data Exchange (ETDEWEB)

    Havukainen, R. [ed.

    1997-05-01

    At the end of 1996, there were 1,762 valid safety licences in Finland for the use of radiation. In addition, there were 2,052 responsible parties for dental x-ray diagnostics. The registry of the Finnish Centre for Radiation and Nuclear Safety listed 13,360 radiation sources and 313 radionuclide laboratories. The import of radioactive substances amounted to 1.14 x 10{sup +16} Bq and export to 7.78 x 10{sup +13} Bq. A total of 4.02 x 10{sup +13} Bq of short-lived radionuclides were produced in Finland. There were 11,842 workers monitored for radiation exposure at 1,352 work sites. Of these employees, 27% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of individual dosimeter readings) was 7.96 manSv in 1996, with nuclear power plant workers accounting for 69% of this total. The annual dosimeter reading of ten medical doctors (radiologists, interventional radiologists and cardiologists) and eight nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of dosimeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 242 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations where unusually high exposure to radiation was an unavoidable part of the task. Report was made of 12 incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Five of these cases occurred in radiotherapy, three in use of a radiation source in industry, three in transport of radiation sources and one in use of solarium appliances. Radiation-contaminated material was found in 17 shipments of scrap. (orig.)

  2. A facies distribution model controlled by a tectonically inherited sea bottom topography in the carbonate rimmed shelf of the Upper Tithonian-Valanginian Southern Tethyan continental margin (NW Sicily, Italy)

    Science.gov (United States)

    Basilone, Luca; Sulli, Attilio

    2016-08-01

    The Upper Tithonian-Valanginian shallow-water carbonates outcropping in the Palermo Mts (NW Sicily) consist of several facies associations reflecting different depositional environments of a carbonate rimmed shelf, pertaining to the Southern Tethyan continental margin. The reconstructed depositional model, based on the sedimentological features, cyclic facies arrangement and biota distribution, shows that a wide protected lagoon, dominated by algae, molluscs and scattered patch reefs, was bordered landward by a tidal flat, where stromatolitic algal mats were cyclically subaerial exposed, and seaward by a marine sand belt and reef complex. Oolitic packstone-grainstone lithofacies, cyclically subjected to subaerial exposure, suggests the occurrence of a barrier island, located nearly to the lagoonal carbonate shoreline, allowing the development of narrow embayments with restricted circulation. In the outer platform, the oolitic lithofacies of the marine sand belt pass landward into the protected lagoon, where washover oolite sands occur, and seaward into a high-energy zone (back-reef apron) gradually merging in the reef complex. In the latter, coral framestone occupied the inner sector (reef flat), while the facies association dominated by boundstone with Ellipsactinia sp. developed in the outer sectors (reef wall), adjacent to the fore-reef and upper slope environments. Stratigraphic evidence, associated with the recognized facies associations, helped to reconstruct the geo-tectonic setting of the carbonate platform, where the distribution of the depositional facies along the shelf and their extension were influenced by the tectonically-inherited sea bottom topography. In a regime of extensional tectonics, localized and thin succession of high-energy prograding oolite sand belt depositional facies occupied structural highs (footwall uplift), while the largely diffused and thick low energy aggrading peritidal-to-lagoonal depositional facies developed in subsiding

  3. Geologic mapping of the Hi’iaka and Shamshu regions of Io

    Science.gov (United States)

    Bunte, Melissa K.; Williams, David A.; Greeley, Ronald; Jaeger, Windy L.

    2010-06-01

    We produced regional geologic maps of the Hi'iaka and Shamshu regions of Io's antijovian hemisphere using Galileo mission data to assess the geologic processes that are involved in the formation of Io's mountains and volcanic centers. Observations reveal that these regions are characterized by several types of volcanic activity and features whose orientation and texture indicate tectonic activity. Among the volcanic features are multiple hotspots and volcanic vents detected by Galileo, one at each of the major paterae: Hi'iaka, Shamshu, and Tawhaki. We mapped four primary types of geologic units: flows, paterae floors, plains, and mountains. The flows and patera floors are similar, but are subdivided based upon emplacement environments and mechanisms. The floors of Hi'iaka and Shamshu Paterae have been partially resurfaced by dark lava flows, although portions of the paterae floors appear bright and unchanged during the Galileo mission; this suggests that the floors did not undergo complete resurfacing as flooding lava lakes. However, the paterae do contain compound lava flow fields and show the greatest activity near the paterae walls, a characteristic of Pele type lava lakes. Mountain materials are tilted crustal blocks that exhibit varied degrees of degradation. Lineated mountains have characteristic en echelon grooves that likely formed as a result of gravitational sliding. Undivided mountains are partially grooved but exhibit evidence of slumping and are generally lower elevation than the lineated units. Debris lobes and aprons are representative of mottled mountain materials. We have explored the possibility that north and south Hi'iaka Mons were originally one structure. We propose that strike-slip faulting and subsequent rifting separated the mountain units and created a depression which, by further extension during the rifting event, became Hi'iaka Patera. This type of rifting and depression formation is similar to the mechanism of formation of terrestrial

  4. Workload spectra and occupational dosimetry in interventionist radiology

    International Nuclear Information System (INIS)

    Interventionist radiology is one of the imaging modalities which provides higher staff doses. This occurs firstly because the professionals involved on the conduction of the procedures must be close to the patient, and also because the workload required for generating adequate images is substantially high. Therefore, national standards and international recommendations of radiation protection specify the use of lead aprons, thyroid protector and individual monitoring. The workload spectra of 247 interventionist procedures were registered. These angiographic procedures were grouped on 149 cardiac, 66 neurological; and 32 peripheral ones. Additional information regarding the patient age, sex and weight were also obtained. The professionals conducting the procedures were grouped on three categories: physician 1, physician 2 and nurse. These categories are basically related to the proximity of these professionals to the patient during the procedures; and, consequently, are related to the individual doses received. Each staff category was monitored for a group of procedures using thermoluminescent dosimeter (TLD) specially selected and calibrated to the purpose of this work. The evaluated workload spectra presented peaks around 75 kV and 110 kV for cardiologic investigations, and around 65 kV for neurology, and an approximately uniform distribution for peripheral procedures. The results of the workload evaluation presented 61.3 mA.min per patient in neurological angiographic procedures, 99.0 mA.min per patient in peripheral angiographic procedures, and 170.7 mA.min per patient in cardiac procedures. The mean individual doses evaluated per procedure were on the intervals from (0.003±0.001) mSv to (0.101±0.022) mSv for neurology angiography procedures, from (0.004±0.001) mSv to (0.104±0.022) mSv for peripheral angiography procedures, and from (0.124±0.023) mSv to (0.189±0.048) mSv for cardiac procedures. These workload and dose values can be used as institutional

  5. GPR in Ramboll

    Science.gov (United States)

    Ringgaard, Jørgen; Wisén, Roger

    2014-05-01

    has contributed to aninternational collaboration between several countries about preparation of guidelines for application of GPR on roads, the Mara Nord Project. Our 3D system is used for various types of surveys. In airports mapping has been performed both on runways, taxiways and aprons with the aim of mapping layer thicknesses and delamination for planning of maintenance work. Acquisition has also been done on roads for control of asphalt works and mapping of the road bed. On bridges mapping of rebars and structure has been performed. The 3D system is also used for determination of space behind frost insulation walls in tunnels in Norway. This work is based on a pilot project made by SINTEF in Norway. This abstract is a contribution to COST Action TU1208.

  6. Dam Sites In Terrains of Soluble Rocks: A Model of Increasing Leakage By Dissolutional Widening of Fractures

    Science.gov (United States)

    Romanov, D.; Gabrovsek, F.; Dreybrodt, W.

    Water flowing through narrow fractures of soluble rock, e. g. limestone and gypsum widens these by chemical dissolution. This process called karstification sculptures subterranean rivers which drain most of their catchment. Close to dam sites unnatu- rally high hydraulic gradients exist to drive the impounded water downstream through fractures reaching below the dam. This poses the question whether under such condi- tions karstification beneath the dam is accelerated to such an extent that high leakage arises. Model simulations by coupling dissolutional widening and hydrodynamic flow are presented. The scenario is a dam 100 m wide with flanks of insoluble rock; but its bottom is limestone or gypsum. The modelling domain is a two-dimensional slice 1 m wide directed perpendicular to the dam. It extends 375 m vertically and 750 m horizontally. The dam is located in its center. This domain is divided by fractures with average aperture width of 0.02 cm into blocks of 7.5 m x 7.5 m x 1 m. We have per- formed model runs for a dam site with 150 m height of impounded water, a horizontal impermeabilization apron 131 m wide, and a grouting curtain reaching down 97 m. To calculate widening of the fractures experimental data on the dissolution of limestone and gypsum are used. All runs exhibit a characteristic behaviour. Shortly after fill- ing the reservoir there is small leakage of about 0.01 m3s-1, which increases steadily until a breakthrough event occurs after several 10 years with an abrupt increase of leakage to about 0.1 m3s-1 within a few years. Then flow in the fractures becomes turbulent and the leakage increases to 10 m3s-1 in about 10 years. Small channels propagate downstream and leakage rises slowly until the first channel has reached the surface causing breakthrough and establishing a dense net of flow pathways. We have performed a sensitivity analysis of the dependence of breakthrough times on the height of impounded water, the depth of grouting, the average

  7. Radiation practices 1997

    International Nuclear Information System (INIS)

    At the end of 1997, there were 1,753 valid safety licenses in Finland for the use of radiation. In addition, there were 2,065 responsible parties for dental x-ray diagnostics. The registry of STUK - Radiation and Nuclear Safety Authority listed 13,839 radiation sources and 302 radionuclide laboratories. The import of radioactive substances amounted to 1.09 x 10+16 Bq and export to 2.4 x 10+13 Bq. Short-lived radionuclides produced in Finland amounted to 5.2 x 10+13 Bq. There were 11,773 workers monitored for radiation exposure at 1,316 work sites. Of these employees, 24% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of the individual dosemeter readings) was 6.6 Sv in 1997, with nuclear power plant workers accounting for 62% of this total. The annual dosemeter reading of thirteen medical doctors (radiologists, interventional radiologists and cardiologists) and six nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of the dosemeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 253 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations in which unusually high exposure to radiation was an unavoidable part of the task. Reports were made of four incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Two of these cases occurred in the medical use of radiation, one in the use of radiation sources in industry, and one in the use of solarium appliances. (orig.)

  8. Veiki-moraine-like landforms in Nereidum Montes on Mars: Insights from analogues in northern Sweden.

    Science.gov (United States)

    Johnsson, Andreas; Reiss, Dennis; Hauber, Ernst; Johnson, Mark D.; Olvmo, Mats; Hiesinger, Harald

    2016-04-01

    Mars is a cold hyper-arid planet where liquid water is extremely rare [1]. The observable water budget is instead found in a number of frozen reservoirs such as the polar caps, near surface ground ice and as glacier ice. Previously, numerous studies reported on glacier landforms such as viscous flow features and lobate debris aprons where water-ice is believed to be present under insulating debris cover [2]. This notion was confirmed by SHARAD measurements [3]. However, very little is known about glacial landforms in which water is an important factor. Most studies have focused on moraine-like ridges that are associated to gully systems [4], glacial landforms at the equatorial volcanic province [5] and possible drop-moraines from CO2 glaciers [6]. Here we report on an unusual lobate assemblage of irregular ring-shaped landforms within a mountain complex in Nereidum Montes, Mars. These landforms are well-preserved and may suggest recent ablation of a debris-covered glacier. These martian ring-shaped landforms show a striking morphological resemblance to the Veiki moraine in northern Sweden. Veiki moraines are believed to have formed at the lobate margins of a stagnant ice-sheet during the first Weichselian glaciation [7]. As it sharply ends to the east it may represent the maximum extent of this former ice sheet. The Veiki moraine is characterized by ridged plateaus that are more or less circular and surrounded by a rim ridge. The newly acquired national LiDAR data over Sweden enable us studying these landforms in unprecedented detail. They also enable us exploring geomorphological similarities between Earth and Mars in large spatial contexts. This study aims to increase our understanding of glacial landforms on Mars by comparison to terrestrial analogues. Questions addressed are: (1) How morphological similar are the Martian landforms to the Veiki moraine of Sweden? (2) How does the ring-shaped landforms relate to other possible glacial landforms within the

  9. Lunar Regolith Maturity Controlled By Ilmenite Content And Micro-Meteor Flux Variability

    Science.gov (United States)

    Schmitt, H. H.

    2013-12-01

    Synthesis of Is/FeO maturity indexes for Apollo 17 regolith samples in the valley of Taurus-Littrow on the Moon indicate that high levels of ilmenite in the samples significantly reduces the level of this indicator of space exposure. The analysis, along with consideration of regolith glass characteristics, also discloses that micro-meteor fluxes vary over geologic time, presumably in response to significant impact events in the Asteroid Belt. Surface samples of ilmenite-poor, silicate-rich regolith have about 80-90% higher maturity indexes than surface samples of ilmenite-rich, basaltic regolith of comparable exposure. For comparison of the history of various regolith exposures to the space environment, Taurus-Littrow's light mantle avalanche deposit, the youngest large area stratigraphic unit, provides a specific time horizon. For at least the last ~110 million years, the currently estimated age of the light mantle avalanche, most near surface (upper 1-5cm) regolith has had approximately the same exposure to micro-meteors. The surface of the largely ilmenite-rich basalt fill in the valley has been exposed to space at least as long or possibly 30 million years longer than the light mantle, based on exposure ages for large boulder ejecta in the Camelot cluster of craters. High apparent maturity (Is/FeO >80), however, exists only on three types of regolith surfaces: (1) the North Massif apron (e.g., 77431), (2) the light mantle avalanche deposit (e.g., 72161), and (3) low ilmenite basalt (e.g., 72150). Only intermediate to low maturity (Is/FeO orange ash, has exceptionally low maturity (8% agglutinates and Is/FeO = 5) but an unusually high amount of "ropy" glass (14-18%). (Ropy glass normally constitutes less than on percent of new Taurus-Littrow regolith. It forms within fresh impact craters as a result of macro-meteor impacts, but the current flux of micro-meteors disaggregates such glass within a million years or less.) The light mantle avalanche deposit protected

  10. Efficacy of Breast Shielding During CT of the Head

    International Nuclear Information System (INIS)

    The use of computerized tomography (CT) is rapidly increasing in last two decades, and this method has become the major non-natural source of radiation exposure to the population. CT examinations delivers to the patients more radiation than all other imaging techniques, and contribute disproportionately to the collective dose; in Britain it has been estimated that 4% of diagnostic radiology procedures are CT examinations, being responsible for approximately 40% of the total annual collective dose. Breast doses are high in CT examinations with breasts in scanning planes, being not insignificant also when breasts are exposed only to scatter radiation. Breast doses received through scatter radiation during head CT may account for up to one-fifth of an average mammographic dose per one view. Whilst the possibilities of reduction of radiation load to organs lying in CT scanning planes are limited, the tissues outside the primary beam should be protected against scatter whenever it does not sacrifice image quality. Lead shielding results in significant reduction of external scatter to radiosensitive superficial organs in many diagnostic procedures. The published studies of breast shielding against scatter radiation in diagnostic radiology are scanty, only the later one dealing particularly with breast shielding during head CT examination. The aims of this study were to investigate in vivo the levels of breast exposure to scatter radiation in head CT examination and the dependence of breast exposure upon body constitution. We tried to estimate the efficacy of external lead shielding as a mean of breast dose reduction, and to determine how much radiation reaches the organ from outside, in comparison to radiation load caused through internal scatter. We conclude that, although the level of breast radiation exposure during head CT examinations is generally low, shielding of the breasts with lead apron will further reduce the doses. However is the effect of shielding limited

  11. The ages of pedestal craters on Mars: Evidence for a late-Amazonian extended period of episodic emplacement of decameters-thick mid-latitude ice deposits

    Science.gov (United States)

    Kadish, Seth J.; Head, James W.

    2014-02-01

    There is significant geomorphologic evidence for the past presence of longitudinally widespread, latitudinally zoned deposits composed of ice-rich material at the northern and southern mid latitudes on Mars (lobate debris aprons, lineated valley fill, concentric crater fill, pedestal craters, etc.). Among these features, pedestal craters (Pd) are impact craters interpreted to have produced a protective layer on top of decameters-thick ice deposits now missing in intercrater regions. The time during which these various deposits were present is still highly debated. To address this question we have analyzed the distribution and characteristics of pedestal craters; here, we use a population of 2287 pedestal craters (Pd) to derive a crater retention age for the entire population, obtaining a minimum timescale of formation of ~90 Myr. Given that the ice-rich deposit has not been continuously present for this duration, the timescale of formation is necessarily longer than ~100 Myr. We then compiled impact crater size-frequency distribution dates for 50 individual pedestal craters in both hemispheres to further assess the frequency distribution of individual ages. We calculated pedestal crater ages that ranged from ~1 Myr to ~3.6 Gyr, with a median of ~140 Myr. In addition, 70% of the pedestal ages are less than 250 Myr. During the 150 Myr period between 25 Ma and 175 Ma, we found at least one pedestal age every 15 Myr. This suggests that the ice-rich paleodeposit accumulated frequently during that time period. We then applied these results to the relationship between obliquity and latitudinal ice stability to suggest some constraints on the obliquity history of Mars over the past 200 Myr. Atmospheric general circulation models indicate that ice stability over long periods in the mid latitudes is favored by moderate mean obliquities in the ~35° range. Models of spin-axis/orbital parameter evolution predict that the average obliquity of Mars is ~38°. Our data represent

  12. Forestry and charcoal burning in the vicinity of the ironwork Peitz (South Brandenburg, Germany) - What do we know from historical and archaeological data?

    Science.gov (United States)

    Takla, Melanie; Frank, Müller; Horst, Rösler; Raab, Alexandra; Raab, Thomas

    2014-05-01

    The former royal forest districts around Peitz (South Brandenburg, Germany) were used to produce charcoal for the ironwork Peitz (1554 to 1856). More than 800 archaeologically excavated ground plans of charcoal kilns give evidence of the burning activity in the study area "Jänschwalde Heide" which is only a small part of the whole forest district. The study area in the apron of the active lignite mine Jänschwalde comprises the royal forest "Jänschwalder Heide" and the surrounding community forests. Our study approach combines archaeological research, a GIS-based approach (historical maps, airborne laser scanning (ALS) data, etc.) and archival studies. The charcoal kilns have been registered since 1990 and since 2005 they are systematically excavated and documented. First dendrochronological data reach from the 17th to the 19th century confirming charcoal burning during the operation period of the iron work. Moreover 5000 additional kilns were identified and digitized from Shaded Relief Maps (SRM) created from ALS data (resolution 1p m-2; height accuracy +- 15 cm). A kiln field of such a dimension has not been documented and investigated for the North German Lowlands so far. It raises the question about the effects of charcoal burning on the forests and the landscape during the last three hundred years. Here we present the evaluation of the kiln data with regard to their size, frequency and spatial distribution. Besides the large number, the kilns have also large diameters (modal value 17 m, mean 12,5 m). Outside the boundaries of the royal forest the kilns are smaller and they were probably used to produce charcoal for local handcraft. These findings are compared to historical records from the first forest inventories (18th/19th century) like forest age and area, with historical forest laws and wood consumption data of the iron work. There is growing evidence that despite of the large extent of the kiln field the wood reserves in the forest districts about 1800

  13. Effects of hygiene-sanitary measures on microbiological safety of finished product in butter production plant

    Directory of Open Access Journals (Sweden)

    Memiši Nurgin

    2012-01-01

    Full Text Available This work presents the results of investigations of the effects of hygienesanitary measures at critical points in the technological process of butter production on its quality and microbiological safety. With this object in mind, hygiene safety was checked using the swab method at the machine for churning and packing butter (125 g packages and bulk butter, the equipment, hands and clothing (work aprons of employees directly engaged on the machines. The evaluation of the safety parameters, as well as of the hygiene of the production process itself, was carried out in keeping with the Regulations on general and special conditions of food hygiene at any stage of production, processing and trade (RS Official Gazette, No.72/2010. The results of the hygiene safety of swabs taken from the 125g-butter packing machine, after sanitation, showed an increased number of mesophilic bacteria (up to 90 cfu/cm2, as well as the presence of bacteria from the Family Enterobacteriaceae (4 cfu/cm2. The results of swabs taken from the hands of workers engaged on the line for wrapping the butter following the churning process and on the packing line reveal the presence of aerobic mesophilic sporogenic bacteria (20 cfu/cm2, while the presence of pathogenic microorganisms was not established. Butter samples packed into 125g portions present more risky forms of commercial packaging than bulk butter, which is a consequence of various handling activities and additional outside contamination that takes place during the production process if continuous production in the plant has not been ensured. Moreover, the established presence of certain microorganisms (aerobic mesophilic microorganisms, lipolytic bacteria, as well as fungi in packed butter during its shelf life, is largely a result of outside contamination and the hygienic condition of the equipment. The obatined results of the investigations indicate the need for special attention to be paid during the butter

  14. Combined tectonic-sediment supply-driven cycles in a Lower Carboniferous deep-marine foreland basin, Moravice Formation, Czech Republic

    Science.gov (United States)

    Bábek, Ondřej; Mikuláš, Radek; Zapletal, Jan; Lehotský, Tomáš

    The Lower Carboniferous Moravian-Silesian Culm Basin (MSCB) represents the easternmost part of the Rhenohercynian system of collision-related, deep-water foreland basins (Culm facies). The Upper Viséan Moravice Formation (MF) of the MSCB shows a distinct cyclic stratigraphic arrangement. Two major asymmetric megacycles bounded by basal sequence boundary, each about 500 to 900 m thick, have been revealed. The megacycles start with 50- to 250-m-thick, basal segments of erosive channels: overbank successions and slope apron deposits interpreted as lowstand turbidite systems. Up-section they pass into hundred metre-thick, fine-grained, low-efficiency turbidite systems. Palaeocurrent data show two prominent directions, basin axis-parallel, SSW-NNE directions, which are abundant in the whole MF, and basin axis-perpendicular to oblique, W-E to NW-SE directions, which tend to be confined to the basal parts of the megacycles or channel-lobe transition systems in their upper parts. Based on the facies characteristics, palaeocurrent data, sandstone composition data and trace-fossil distribution data, we suggest a combined tectonics-sediment supply-driven model for the MF basin fill. Periods of increased tectonic activity resulted in slope oversteepening probably combined with increased rate of lateral W-E sediment supply into the basin, producing the basal sequence boundary and the subsequent lowstand turbidite systems. During subsequent periods of tectonic quiescence, the system was filled mainly from a distant southern point source, producing the thick, low efficiency turbidite systems. Consistently with the previous models, our own sediment composition data indicate a progressively increasing sediment input from high-grade metamorphic and magmatic sources up-section, most probably related to an uplift in the source area and progressive unroofing of its structurally deeper crustal parts. The first occurrence of the Cruziana-Nereites ichnofacies in sand-rich turbidite

  15. Veiki-moraine-like landforms in the Nereidum Montes region on Mars: Insights from analogues in northern Sweden.

    Science.gov (United States)

    Johnsson, A.; Reiss, D.; Hauber, E.; Johnson, M. D.; Olvmo, M.; Hiesinger, H.

    2015-10-01

    Mars is a cold hyper-arid planet where liquid water is extremely rare [1]. Most water is instead locked in a number of frozen reservoirs such as the polar caps, latitude-dependent near surface ground ice and as glacier ice. Previously, numerous studies reported on glacier landforms such as viscous flow features and lobate debris aprons where water-ice is believed to be present under insulating debris cover[2].This notion was confirmed by SHARAD measurements [3].However, very little is known about glacial landforms in which water is an important factor. Most studies have focused on moraine- like ridges that are associated to gully systems in crater environments[4], glacier landforms at the equatorial volcanic province [5]and drop-moraines from CO2 glaciers [6]. Here we report on unusual irregular ring-shaped landforms within a mountain complex in Nereidum Montes, Mars. These landforms are well-preserved and may suggest recent ablation of a debris-covered,cold-based glacier. These martian ring-shaped moraine-like landforms show a striking resemblance to the Veiki moraine in northern Sweden. Veiki moraines are believed to have formed at the lobate margins of a stagnant ice- sheet during the first Weich selian glaciation as it sharply ends to the east [7].The Veiki-moraine is characterized by ridged plateaus that are more or less circular and surrounded by a rim ridge. The newly acquired national LiDAR data over Sweden enable us studying these landforms in unprecedented detail. They also enable us exploring geomorphological similarities between Earth and Mars in large spatial contexts. This study aims to increase our understanding of glacial landforms on Mars by comparison to terrestrial analogues. Questions addressed are: (1) how morphological similar are the Martian landforms to the Veiki moraine of Sweden? (2) How does the moraine-like landform relate to other, well-preserved, glacial landforms within the mountain complex? (3) Do the moraine-like land forms indicate

  16. Seabed Filter Feasibility Study of Om Almisk Island

    KAUST Repository

    Sesler, Kathryn

    2012-06-01

    Freshwater access has always been and is continuing to be a severe problem in desert coastal regions, despite the fact that they have an unlimited supply of easily accessible saline water. Water desalination plants are well established and heavily relied upon throughout the Middle East, Saudi Arabia in particular. However, water desalination tends to be a very expensive and energy intensive solution to the problem. The transition from using open water intake systems and all of the pretreatment processes that they require, to using seabed water filters as an intake, would potentially reduce the lifetime costs, energy consumption, and environmental impacts commonly associated with water desalination. This is because the filtration process that the seabed filter generates, serves as sufficient pretreatment for seawater as well as eliminating any risk of entrainment or impingement of marine organisms. The main objective of this research is to conduct a feasibility study on Om Almisk Island, an island off the coast of King Abdullah University of Science and Technology (KAUST), to determine if it would be a suitable location to construct a seabed water filter as a replacement for the current open water intake. The Om Almisk Island site was evaluated through collection of sand samples over a radial grid around Om Almisk Island and sample analysis using grain size distribution, porosity, and hydraulic conductivity. The lack of mud, high hydraulic conductivity, proximity to KAUST, and the shallow waters of the sandy apron surrounding Om Almisk Island make this an ideal location for a seabed water filter to be used as an intake and pretreatment for the KAUST desalination plant. This location also has low tide change and the presence of benthic macrofauna to create bioturbation in the sediments, which could inhibit the growth of a schmutzdecke. If this biological layer forms, it could drastically reduce the hydraulic conductivity of the system. Due to the high hydraulic

  17. PERCEPTUAL HOLISTIC APPROACH IN TEACHING LEARNING OF ATHLETICS THROUGH GAMES / ENFOQUE HOLÍSTICO PERCEPTUAL EN LA ENSEÑANZA-APRENDIZAJE DEL ATLETISMO A TRAVÉS DEL JUEGO

    Directory of Open Access Journals (Sweden)

    Rolando Castro Marcelo

    2013-04-01

    Full Text Available The game as a teaching learning method of athletics in ages ranging from nine to eleven years in Las Tunas province brings about the movement development in school children who can show themselves in a conscious and spontaneous manner. It contributes to their interest and necessities satisfaction through the closed sport in a developing environment which allows to dead with the fundamental dimensions and links with the purpose of reaching the right levels in the formation, education and development of personality in life, here, it is where the talented ones emerge and became high performance athletes. Methodological, epistemological, axiological and critical element in the game declivity; sustained apron theoretical bases are integrated with the intention of permitting the holistic, historic, multifunctional, humanistic and the developing conceptual character. On this point, the unity of theoretical elements and the sport practice is revealed in correspondence with the individual characteristics and peculiarities of catch schoolchild. RESUMEN: El juego como método de enseñanza-aprendizaje del atletismo en las edades de nueve a once años en la provincia de Las Tunas, propicia el desarrollo de los movimientos del escolar, que se pueden manifestar en forma espontánea y consciente, lo que contribuye a la satisfacción por esa vía de sus necesidades e intereses a través del deporte elegido, en un ambiente desarrollador que permite abordar las dimensiones y eslabones fundamentales con el propósito de lograr los niveles deseados de educación, formación y desarrollo de la personalidad, que ha aporte las vías indispensables en su preparación para la vida, de donde emergen los que poseen talento para convertirse en atletas de alto rendimiento. En la actividad del juego se integraron los elementos metodológicos, axiológicos, epistemológicos y críticos, los cuales se sustentan sobre bases teóricas que permiten el carácter holístico, hist

  18. Intraoral radiology in general dental practices. A comparison of digital and film-based X-ray systems with regard to radiation protection and dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Anissi, H.D. [Ulm Univ. (Germany). Dentistry; Geibel, M.A. [Ulm Univ. (Germany). Dept. of Dentomaxillofacial Surgery

    2014-08-15

    Purpose: The purpose of this study was to gain insight into the distribution and application of digital intraoral radiographic techniques within general dental practices and to compare these with film-based systems in terms of patient dose reduction. Materials and Methods: 1100 questionnaires were handed out to general dental practitioners. Data was analyzed with respect to the type of system by using descriptive statistics and nonparametric tests, i.e. Kruskal-Wallis, Mann-Whitney and chi-square test (SPSS 20). Results: 64% of the questioned dentists still use film-based radiology, 23% utilize storage phosphor plate (SPP) systems and 13% use a charge-coupled device (CCD). A strong correlation between the number of dentists working in a practice and the use of digital dental imaging was observed. Almost 3/4 of the film users work with E- or F-speed film. 45% of them refuse to change to a digital system. The use of lead aprons was popular, while only a minority preferred thyroid shields and rectangular collimators. A fourfold reduction of exposure time from D-speed film to CCD systems was observed. Due to detector size and positioning errors, users of CCD systems take significantly more single-tooth radiographs in total. Considering the number of radiographs per patient, there is only a slight tendency towards more X-rays with CCD systems. Up to image generation, digital systems seem to be as or even more difficult to handle than film-based systems, while their handling was favored after radiographic exposure. Conclusion: Despite a slight increase of radiographs taken with CCD systems, there is a significant dosage reduction. Corresponding to the decrease in exposure time, the patient dose for SPP systems is reduced to one half compared to film. The main issues in CCD technology are positioning errors and the size of the X-ray detectors which are difficult to eliminate. The usage of radiation protection measures still needs to be improved. (orig.)

  19. Angiographer's exposure to radiation under different fluoroscopic imaging conditions

    International Nuclear Information System (INIS)

    Scattered radiation levels near an imaging system commonly used in angiography were measured with a 200 mm thick water phantom. The scattered radiation exposure rate was measured in lines parallel in space to the central ray of the x-ray beam, at lateral distances of 30-100 cm. The effects of an x-ray beam limiting device, geometric and electric magnification, and rotation angle of the C-arm were also determined. The results indicated that the highest scattered radiation levels occurred near the surface of the phantom where the x-ray beam enters. In P-A geometry, the highest radiation levels occurred below the angiographer's waist. These areas of the body corresponded to the gonads of the angiographer. It has been suggested that angiographers' exposure rates are higher near the gonads than near the chest. However, lead aprons efficiently protect these areas. When smaller field sizes were limited by a variable x-ray beam limiting device, the volume of irradiated tissue was reduced, and the scattered radiation exposure rate was decreased. Further, when larger magnification factors were chosen for the analogue magnification method, the volume of irradiated tissue was reduced by the automatic x-ray beam limiting device, and the scattered radiation exposure rate was decreased. However, smaller field sizes markedly increased patient exposure by auto brightness control. To mitigate the angiographer's exposure, smaller field sizes with x-ray limiting devices are required. However, a larger field size should be used whenever possible to minimize patient exposure. The angiographer's exposure rate was influenced by the incidence direction of the x-ray beam when the C-arm had been rotated around the phantom. Consequently, the angiographer's exposure rate was maximum when the x-ray tube most closely approached the angiographer and was minimum when the image intensifier most closely approached the angiographer. Therefore, to mitigate the angiographer's exposure, attention needs

  20. Radiation protection of medical staff: a coordinated action by EURADOS on extremely dosimetry and the use of active personnel dosemeters (CONRAD)

    International Nuclear Information System (INIS)

    Monitoring of workers constitutes an integral part of any radiological protection program. However, unresolved issues in radiation protection of medical staff still remain. Research and establishment of guidelines are necessary on a variety of issues such as extremity dosimetry (fingers, eye lenses, etc), the use of double dosimetry above and below lead aprons, or the use of electronic personal dosimeters in interventional procedures. Medical practices are also evolving fast, and new techniques with ionising radiation emerge very regularly, thus implying the need of radiation protection measures for medical staff, and the implementation of new monitoring programs. In some medical applications of radiation there is an increased risk of high local exposures because of direct handling of sources or the use of beta-emitters. However, despite the large number of workers that are exposed in the medical field worldwide, only few measurements of extremity doses have been reported in the literature. Some activities of EURADOS Working Group 9 (WG9) were sponsored by the European Commission in the CONRAD project. This CONRAD project was aiming at the coordination of research on radiation protection at the workplace. Working group 9 has been involved in the coordination and promotion of European research in the field of Radiation Protection Dosimetry for Medical Staff. One of the objectives of this working group was to formulate the state of the art and to identify areas in which improvements were needed. For some of these medical applications the skin of the fingers is the limiting organ from the point of view of individual monitoring of external radiation. The wide variety of radiation field characteristics in a medical environment, and the difficulty of measuring a local dose that is representative for the maximum skin dose (usually with one single detector), makes it difficult to perform extremity dosimetry with an accuracy similar to whole-body dosimetry. Therefore a

  1. Development and implementation of a quality assurance system in odontological radiology

    International Nuclear Information System (INIS)

    According to surveys by the Comissao Nacional de Engenharia Nuclear (CNEN), in odontological radiology, it was concluded that more than 80% of the radiological examinations are performed with entrance skin doses greater than 2.5 mGy, that approximately 85% of the dentists sub develop the films and 40% of the equipment present deficiencies in collimation, filtration and other problems. This is a critical situation for the population's quality of life, which requires prompt intervention to improve Odontological Radiology Services (ORS). The main purpose of this work is to elaborate a process of implementation and management of a Quality Assurance Program (QAP) in Odontological Radiology Services using as a pilot area the state of Sao Paulo. The methodology was based on the orientation of the professionals to safely obtain the best image for diagnostic and its interpretation with the available resources. The strategy was based in monitoring exposure (kVp, time, output, consistency) and geometric (collimation, filtration and contrast) parameters. Internal procedures were also considered such as development control, rejection rate analysis, working conditions of the dentists' office as well as the keeping of a register note book. Results indicate that entrance skin doses greater than 2.5 mGy in 84% of the cases reduced to 43%. Collimation, that before implementation of the QAP was greater than 6 cm in 61% of the cases reduced to only 3%. The following aspects were not considered before the implementation of the QAP and after, 100% of them were applied in the dentists' offices: processing, rejection rate, the keeping of a register note book and the posting of a sign with a warning saying that it is obligatory the use of lead apron. The main difficulties which arose from this work were the meetings with the dentists in order to convince them of the importance of the QAP. Motivation of fully compensated by their attachment to the Program. Results show that work was fully

  2. Depositional facies and aqueous-solid geochemistry of travertine-depositing hot springs (Angel Terrace, Mammoth Hot Springs, Yellowstone National Park, U.S.A.)

    Science.gov (United States)

    Fouke, B. W.; Farmer, J. D.; Des Marais, D. J.; Pratt, L.; Sturchio, N. C.; Burns, P. C.; Discipulo, M. K.

    2000-01-01

    Petrographic and geochemical analyses of travertine-depositing hot springs at Angel Terrace, Mammoth Hot Springs, Yellowstone National Park, have been used to define five depositional facies along the spring drainage system. Spring waters are expelled in the vent facies at 71 to 73 degrees C and precipitate mounded travertine composed of aragonite needle botryoids. The apron and channel facies (43-72 degrees C) is floored by hollow tubes composed of aragonite needle botryoids that encrust sulfide-oxidizing Aquificales bacteria. The travertine of the pond facies (30-62 degrees C) varies in composition from aragonite needle shrubs formed at higher temperatures to ridged networks of calcite and aragonite at lower temperatures. Calcite "ice sheets", calcified bubbles, and aggregates of aragonite needles ("fuzzy dumbbells") precipitate at the air-water interface and settle to pond floors. The proximal-slope facies (28-54 degrees C), which forms the margins of terracette pools, is composed of arcuate aragonite needle shrubs that create small microterracettes on the steep slope face. Finally, the distal-slope facies (28-30 degrees C) is composed of calcite spherules and calcite "feather" crystals. Despite the presence of abundant microbial mat communities and their observed role in providing substrates for mineralization, the compositions of spring-water and travertine predominantly reflect abiotic physical and chemical processes. Vigorous CO2 degassing causes a +2 unit increase in spring water pH, as well as Rayleigh-type covariations between the concentration of dissolved inorganic carbon and corresponding delta 13C. Travertine delta 13C and delta 18O are nearly equivalent to aragonite and calcite equilibrium values calculated from spring water in the higher-temperature (approximately 50-73 degrees C) depositional facies. Conversely, travertine precipitating in the lower-temperature (crystals. Despite the production of H2S and the abundance of sulfide oxidizing microbes

  3. Late Cenozoic Magmatic and Tectonic Evolution of the Ancestral Cascade Arc in the Bodie Hills, California and Nevada: Insights from Integrated Geologic, Geophysical, Geochemical and Geochronologic Studies

    Science.gov (United States)

    John, D. A.; du Bray, E. A.; Box, S. E.; Blakely, R. J.; Fleck, R. J.; Vikre, P. G.; Cousens, B.; Moring, B. C.

    2012-12-01

    Geologic mapping integrated with new geophysical, geochemical, and geochronologic data characterize the evolution of Bodie Hills volcanic field (BHVF), a long-lived eruptive center in the southern part of the ancestral Cascade arc. The ~700 km2 field was a locus of magmatic activity from ~15 to 8 Ma. It includes >25 basaltic andesite to trachyandesite stratovolcanoes and silicic trachyandesite to rhyolite dome complexes. The southeastern part of the BHVF is overlain by the ~3.9 to 0.1 Ma, post-arc Aurora Volcanic Field. Long-lived BHVF magmatism was localized by crustal-scale tectonic features, including the Precambrian continental margin, the Walker Lane, the Basin and Range Province, and the Mina deflection. BHVF eruptive activity occurred primarily during 3 stages: 1) dominantly trachyandesite stratovolcanoes (~15.0 to 12.9 Ma), 2) coalesced trachydacite and rhyolite lava domes and trachyandesite stratovolcanoes (~11.6 to 9.7 Ma), and 3) dominantly silicic trachyandesite to dacite lava dome complexes (~9.2 to 8.0 Ma). Small rhyolite domes were emplaced at ~6 Ma. Relatively mafic stratovolcanoes surrounded by debris flow aprons lie on the margins of the BHVF, whereas more silicic dome fields occupy its center. Detailed gravity and aeromagnetic data suggest the presence of unexposed cogenetic granitic plutons beneath the center of the BHVF. Isotopic compositions of BHVF rocks are generally more radiogenic with decreasing age (e.g., initial Sr isotope values increase from ~0.7049 to 0.7061), which suggests progressively greater magma contamination by crustal components during evolution of the BHVF. Approximately circular, polygenetic volcanoes and scarcity of dikes suggest a low differential horizontal stress field during BHVF formation. Extensive alluvial gravel deposits that grade laterally into fluvial gravels and finer grained lacustrine sediments and the westerly sourced Eureka Valley Tuff (EVT; ~9.4 Ma) blanket large parts of the BHVF. The earliest sediments

  4. Carriage of Multidrug Resistant Bacteria on Frequently Contacted Surfaces and Hands of Health Care Workers

    Science.gov (United States)

    Visalachy, Sowndarya; Kopula, Sridharan Sathyamoorthy; Sekar, Uma

    2016-01-01

    Introduction Maximal contact between the patients and Health Care Workers (HCWs) happens in the Intensive Care Units (ICU). Control of nosocomial infections requires compliance with hand hygiene and contamination free surfaces. Aim To determine the colonization of potential pathogens in the hands of HCWs and frequent contacted environmental surfaces. Materials and Methods A cross sectional study was conducted between September 2012 and May 2013 at Sri Ramachandra Medical College and Hospital. A total of 327 samples were collected using Glove juice technique from hands and swabs from frequently contacted surfaces. A sum of 157 samples were collected by glove juice technique from the hands of HCWs which included Consultants (20), Internees (3), Residents (10), Staff nurse (102) and support staff (22). A total of 170 samples were collected through swabbing which included frequently touched surfaces of apron and dress (140 which included 10 consultants, 3 internees, 9 Residents, 101 Staff nurse and 17 support staff), 9 door handle, 4 key board, 12 tap handles and 5 monitors. The samples were inoculated into Blood agar, Chocolate agar and Mac-Conkey agar plates and incubated at 370C aerobically. The plates showing growth were further processed to identify the organisms by Gram staining and biochemical reactions. Antibiotic susceptibility testing was done for the isolates by Kirby-baur disc diffusion method as per CLSI guidelines. Results Out of the 157 hand sampling done by glove juice method 67(42.7%) of them showed growth and 90(57.3%) showed no growth. The potential pathogens grown were 13 (8.3%), consisting of Methicillin Sensitive Staphylococcus aureus (MSSA) 6(3.8%), Methicillin Resistant Staphylococcus aureus (MRSA) 2(1.3%), Pseudomonas spp 4(2.6%) and Acenitobacter spp 1 (0.6%). The MRSA was seen in Consultant 1(5%; n=20) and Staff nurse 1(0.9%; n= 102). Among the 140 sampling from the dress of HCWs growth was observed in 69(49.3%) and growth was absent in 71

  5. STRATIGRAPHIC CHARACTERISTICS OF THE MESOZOIC-CENOZOIC IN THE SOUTH SHETLAND ISLANDS, ANTARCTICA%西南极南设得兰群岛中新生代地层特征

    Institute of Scientific and Technical Information of China (English)

    王改云; 邓希光; 刘金萍; 杜民

    2013-01-01

    南设得兰群岛是晚中生代以来古太平洋板块向南极板块俯冲消减过程中形成的,目前对整个群岛的地层特征及沉积演化无统一认识.通过归纳总结国内外研究成果,认为该群岛出露的地层具明显的时空规律.群岛主体的西南部出露上侏罗统-下白垩统,发育海底扇、深海、斜坡裙、扇三角洲等沉积相,相伴随的火山作用主要为钙碱性玄武岩和玄武安山岩的喷发,记录了弧前盆地-火山岛弧的演化过程;群岛主体的东北部主要出露上白垩统-下渐新统,其中上白垩统-始新统发育一套玄武质熔岩、火山碎屑-沉积岩建造,为温暖气候下的陆相沉积,火山活动具有岛弧拉斑玄武岩与钙碱性火山岩的过渡性质.渐新统-下中新统则记录了从间冰期正常海相到冰期冰海相沉积的转变过程.%The South Shetland Islands were formed from the subduction of the palaeo-Pacific plate beneath the Antarctic Plate in the late Mesozoic.However,there are no comprehensive records of the stratigraphic characteristics and sedimentary evolution of the entire islands.We examined the distribution of strata by reviewing the literature on the islands published nationally and internationally.The exposed strata in the southwestern South Shetland Islands were mainly from the upper Jurassic-lower Cretaceous.The sedimentary facies included submarine fan,deep sea,marine slope apron,and fan delta.The volcanism was manifested by the eruption of alkaline basalt and basaltic andesite.The evolution from fore-arc basin to volcanic islands has been recorded.The strata in the northeastern South Shetland Islands is mainly upper Cretaceous to Neogene.The sedimentary environment of the upper CretaceousEocene is continental basin in warm climate.The lithology is mainly consisted of basaltic lava,pyroclastic debris and sedimentary rock.Geochemically,the volcanics were transitional from alkaline basalt to tholeiite.The Oligocene

  6. Identification of topographic fingerprints of eruption environments: Geomorphometric evidence from volcanoes of the Reykjanes Peninsula, Iceland

    Science.gov (United States)

    Pedersen, G. B.; Grosse, P.

    2012-12-01

    in slope, such as lava cap, hyaloclastite apron, hyaloclastite slope and hyaloclastite summit. The boundary between hyaloclastite breccia and lava cap represents a passage zone that marks late-stage subaerial lava-fed deltas and is clearly defined by convex breaks in slope. Large elevation changes in the passage zone is diagnostic of lava deltas emplaced in a glacial environment, and thus mapping of elevation changes of convex breaks in slope is a potential tool for distinguishing big table-shaped volcanic edifices emplaced in a submarine or subglacial environment. This study shows that volcano morphometry can be used to obtain information on processes operating during volcano construction, its eruption environment and the resulting evolutionary growth trends. A significant advantage of this method is its application for remote and inaccessible areas such as submarine or subglacial environments as well as extraterrestrial planets. Moreover, the break in slope delimitation of edifice bases and the possibility of resolving individual landform elements makes this geomorphometric analysis directly applicable for advanced mapping techniques such as object-based image analysis.

  7. Geologyy of the Yucca Mountain Site Area, Southwestern Nevada, Chapter in Stuckless, J.S., ED., Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste (Volume 1)

    Energy Technology Data Exchange (ETDEWEB)

    W.R. Keefer; J.W. Whitney; D.C. Buesch

    2006-09-25

    Yucca Mountain in southwestern Nevada is a prominent, irregularly shaped upland formed by a thick apron of Miocene pyroclastic-flow and fallout tephra deposits, with minor lava flows, that was segmented by through-going, large-displacement normal faults into a series of north-trending, eastwardly tilted structural blocks. The principal volcanic-rock units are the Tiva Canyon and Topopah Spring Tuffs of the Paintbrush Group, which consist of volumetrically large eruptive sequences derived from compositionally distinct magma bodies in the nearby southwestern Nevada volcanic field, and are classic examples of a magmatic zonation characterized by an upper crystal-rich (> 10% crystal fragments) member, a more voluminous lower crystal-poor (< 5% crystal fragments) member, and an intervening thin transition zone. Rocks within the crystal-poor member of the Topopah Spring Tuff, lying some 280 m below the crest of Yucca Mountain, constitute the proposed host rock to be excavated for the storage of high-level radioactive wastes. Separation of the tuffaceous rock formations into subunits that allow for detailed mapping and structural interpretations is based on macroscopic features, most importantly the relative abundance of lithophysae and the degree of welding. The latter feature, varying from nonwelded through partly and moderately welded to densely welded, exerts a strong control on matrix porosities and other rock properties that provide essential criteria for distinguishing hydrogeologic and thermal-mechanical units, which are of major interest in evaluating the suitability of Yucca Mountain to host a safe and permanent geologic repository for waste storage. A thick and varied sequence of surficial deposits mantle large parts of the Yucca Mountain site area. Mapping of these deposits and associated soils in exposures and in the walls of trenches excavated across buried faults provides evidence for multiple surface-rupturing events along all of the major faults during

  8. Patient and staff doses and relationships between them in fluoroscopically guided procedures

    International Nuclear Information System (INIS)

    Full text: Medical exposure has the main contribution to man-made sources of exposures to the population in developed countries. Fluoroscopically guided procedures in interventional cardiology, gastroenterology, urology, orthopaedics and others may be related to high doses to both patients and staff. The main risk for both groups is the radiation carcinogenesis and it is increasing with dose. However deterministic effects are also possible: severe patient skin injuries occur sometimes. There are such cases in Bulgarian radiological practice. For the medical staff, involved in the procedures, radiation induced cataract is observed occasionally. Learning objective: In many cases there is direct correlation between patient and staff doses. Several simple rules must be observed in order to decrease exposure. Rules related to patient: Patient dose (dose-area product (DAP), fluoroscopy time, number of series,number of images) should be recorded for every patient; The patient should be positioned as far away as possible from the x-ray tube and as closer as possible to the image intensifier/digital image receptor; Fluoroscopy time should be minimized; Pulsed fluoroscopy with the lowest dose rate and the lowest frame rate providing acceptable image quality should be used; Different skin areas should be exposed in different projections; Oblique projections increase the dose - they should be avoided; Magnification also increases the dose several times and should be avoided; The acquisition mode should be avoided; it delivers dozens of times higher doses. Minimal number of frames and cine runs should be used. Use of “last image hold” is encouraged; The x-ray beam should be collimated to the area of interest. Rules related to staff: The staff receives scattered radiation from patient’s body. Every measure to decrease patient’s dose decreases staff dose as well; Every available protective device should be used (lead apron, thyroid collar, lead glasses, screens). They

  9. Eighth meeting of the radiation protection-skilled persons - Conference proceedings

    International Nuclear Information System (INIS)

    eye lens and workplace analysis (J.M. Bordy); 18 - Efficiency of eye protections in radiology (S. Ouabdelkader); 19 - A necessary evolution of leaded protection jackets and aprons in interventional radiology (J. Guersen); 20 - Selection criteria for measurement devices in agreement with radiation fields (S. Vecchiola); 21 - Radiological tool and zoo veterinary activity (A. Lecu); 22 - New veterinary imaging techniques (C. Roy); 23 - Elimination of old sealed sources: an inextricable and costly path (G. Pigree); 24 - Management of used scelled sources (USS) - Considerations in progress in the framework of the ANDRA PNGMDR working group (B. Sevestre); 25 - Safety measures for field interventions in industrial radiology (C. Bergeron); 26 - Definition of monitored and controlled areas: international aspects (C. Schieber); 27 - Report of the working group on radiological zoning (P. Barbey); 28 - Radiation protection training to the European tune (P. Massiot); 29 - The new framework directive in radiation protection: what evolutions in France? (T. Lahaye); 30 - The project of framework directive in radiation protection (M.L. Perrin)

  10. Fbtr fuel fabrication. The radiological safety aspects

    International Nuclear Information System (INIS)

    related to different operations and plutonium with various isotopic compositions were also established. Maximum dose contribution for a typical batch of plutonium is about 10 mSv in case of final compaction. Reduction of dose has been achieved by using lead shielding in front of the glove boxes and use of lead impregnated aprons, Efforts were made to establish the particle size of plutonium aerosols during various operations which helped in the evaluation of different dose coefficients using standard computational methods. It was found that, the Activity Median Aerodynamic Diameter (AMAD) of plutonium aerosol was less than 0.4 micrometer during sintering operation, Eight stage Anderson cascade impactor was used for this study. In order to establish the distribution in lower range of particles, a twelve stage low pressure cascade impactor was used and the AMAD was found to be 0.23 micrometer. This paper presents the radiological safety aspects of Fbtr fuel fabrication work. (author)

  11. SHARAD Detection of Subsurface Interfaces in Southern-Central Utopia Planitia

    Science.gov (United States)

    Stuurman, C. M.; Brothers, T. C.; Holt, J. W.; Kerrigan, M.; Osinski, G. R.

    2013-12-01

    Characterising the extent and distribution of subsurface ice in the middle-latitudes of Mars is an ongoing endeavour, with applications to both paleoclimate and future missions. Utopia Planitia has been posited as an ice-rich area by climate models, Gamma-Ray Spectrometer results suggestive of high hydrogen concentrations, and high densities of periglacial and glacial surface morphologies. The SHAllow RADar (SHARAD) instrument on the Mars Reconnaissance Orbiter is a radar sounder which transmits a 15-25 MHz chirped pulse. The data is recorded in the time delay and can be used to map and characterize Mars' subsurface. In the Utopia Planitia region, SHARAD data can potentially constrain modeling efforts, help locate potential water resources for future exploration, and give volumetric constraints on features that were previously only observed in two dimensions. Thus far, most mid-latitudinal reflectors using the SHARAD instrument have been associated with isolated surface morphologies, such as lobate debris aprons, lineated valley fill, and reflectors beneath volcanic flows. Recently, SHARAD radargrams over pedestal craters in the mid-latitudes have also yielded results suggestive of water-ice composition, and a massive, radar-transparent layer has been found in Arcadia Planitia. Overall, however, there has been a dearth of SHARAD evidence suggestive of the massive subsurface ice sheets predicted by climate models. This project analyzed several hundred SHARAD radargrams throughout Utopia Planitia. Subsurface reflectors were detected by visually inspecting radar data and comparing to simulated radargrams that predict off nadir surface echoes that can be confused with subsurface reflections. Regions of high amplitude subsurface reflections that do not appear in the simulated radargrams were thus interpreted as reflectors represenative of geologic contacts. SHARAD analysis revealed several reflectors in the Southern-Central Utopia Planitia region. These reflectors were

  12. Geology of the Blue Mountains region of Oregon, Idaho, and Washington; stratigraphy, physiography, and mineral resources of the Blue Mountains region

    Science.gov (United States)

    Vallier, T. L., (Edited By); Brooks, H.C.

    1994-01-01

    PART 1: Stratigraphic and sedimentological analysis of sedimentary sequences from the Wallowa terrane of northeastern Oregon has provided a unique insight into the paleogeography and depositional history of the terrane, as well as establishing important constraints on its tectonic evolution and accretionary history. Its Late Triassic history is considered here by examining the two most important sedimentary units in the Wallowa terrane-the Martin Bridge Limestone and the Hurwal Formation. Conformably overlying epiclastic volcanic rocks of the Seven Devils Group, the Martin Bridge Limestone comprises shallow-water platform carbonate rocks and deeper water, off-platform slope and basin facies. Regional stratigraphic and tectonic relations suggest that the Martin Bridge was deposited in a narrow, carbonate-dominated (forearc?) basin during a lull in volcanic activity. The northern Wallowa platform was a narrow, rimmed shelf delineated by carbonate sand shoals. Interior parts of the shelf were characterized by supratidal to shallow subtidal carbonates and evaporites, which were deposited in a restricted basin. In the southern Wallowa Mountains, lithofacies of the Martin Bridge are primarily carbonate turbidites and debris flow deposits, which accumulated on a carbonate slope apron adjacent to the northern Wallowa rimmed shelf from which they were derived. Drowning of the platform in the latest Triassic, coupled with a renewed influx of volcanically derived sediments, resulted in the progradation of fine-grained turbidites of the Hurwal Formation over the carbonate platform. Within the Hurwal, Norian conglomerates of the Excelsior Gulch unit contain exotic clasts of radiolarian chert, which were probably derived from the Bakei terrane. Such a provenance provides evidence of a tectonic link between the Baker and Wallowa terranes as early as the Late Triassic, and offers support for the theory that both terranes were part of a more extensive and complex Blue Mountains

  13. Quantifying Rates of Complete Microbial Iron Redox Cycling in Acidic Hot Springs

    Science.gov (United States)

    St Clair, B.; Pottenger, J. W.; Shock, E.

    2013-12-01

    Large accumulations of iron oxide commonly occur in shallow outflows of acidic hot springs, and culturing, molecular techniques, and microscopy by others indicate that this iron oxide (often ferrihydrite) is largely biogenic in Yellowstone National Park. The hot springs that support iron mats have several consistent geochemical features including combinations of pH, temperature, sulfide, dissolved oxygen, depth and ferrous iron concentration appropriate to support iron oxidation. These springs nearly always have a point source leading to a large shallow outflow apron. Microbial zones often, but not always, include a small clear zone near the source, followed by a sulfide oxidation zone, iron mat, and finally photosynthesis. The yellow sulfide oxidation zone is separated from the red iron mat by a sharp transition resulting from increasing dissolved oxygen from atmospheric contact and microbial depletion of sulfide. The iron mat is typically the largest microbial zone in the feature by area. Further down the outflow, iron oxidation appears to be outcompeted by phototrophs as the temperature cools. Occasionally there is overlap in these zones, but one metabolism always appears dominant. Our experiments at diverse hot springs indicate that microbial reduction is less geochemically restricted than oxidation, requiring only organic carbon, ferric minerals and an anoxic environment. With iron oxidizers fixing carbon and producing layers of ferric minerals that become rapidly anoxic with depth, iron reduction is invariably proximal to where biogenic iron oxides are forming. To characterize the interplay of oxidation and reduction rates that permit oxide accumulation, we conducted rate experiments at geochemically diverse Yellowstone hot springs featuring visible iron oxides in thermal areas throughout the park. These experiments were performed during two summer field seasons to determine in situ and maximum rates of iron oxidation and reduction by measuring changing

  14. Structural characteristics of Pavonis Mons, Mars, and implications for its volcano-tectonic evolution

    Science.gov (United States)

    Gwinner, Klaus; Head, James W.; Wilson, Lionel

    2010-05-01

    Pavonis Mons is the smallest of the three large Tharsis Montes volcanic edifices on Mars. While Viking-based studies have already revealed main structural features of these shields and have provided a framework on their evolution, detailed information on major aspects of their volcano-tectonic structure and evolution is still incomplete. In particular this is the case for the nature of asymmetries that develop along a NE direction, roughly coincident with the crest line of the Tharsis rise, as well as the evolution of the magma reservoir as the shields were built above the ground, and the related consequences for caldera formation and edifice stability. In addition, different morpho-structural features of the Martian shields have been discussed controversially, such as flank "terraces", rillelike channels, and evidence of flank instabilities. We have analyzed recently available high-resolution data, in particular DTMs with up to 50 m grid spacing derived from HRSC data, as well as high-resolution imagery (HRSC, CTX, HIRISE) and regional-scale MOLA DTMs for obtaining new constraints on the volcano-tectonic structure and evolution of Pavonis. We mapped tectonic elements (faults and fractures, wrinkle ridges, collapse pits), main volcanic elements (vent locations, limits of shield, apron and caldera floor units), and elements of flank morphology. Analysis of edifice morphometry is based on slope maps and slope statistics. We were able to identify several major fault systems affecting flanks and base of the edifice. Widespread occurrence of normal faulting from 2-3 km below the summit plateau to the base shows that the middle and lower flanks are characterized by extension. While the summit plateau and uppermost flanks show evidence for compressional deformation, including wrinkle ridges and downslope-convex flank facets interpreted as surface expression of flank thrusts, the system of intersecting flank facets that have been denoted as compressional "terraces" instead

  15. Geochemical evidence for fluid flow in the upper and subducting plates of the Costa Rica margin: Results from CRISP drilling during Exp. 334 and 344 (Invited)

    Science.gov (United States)

    Torres, M. E.; Solomon, E. A.; Kastner, M.; Harris, R. N.; Formolo, M.; Choi, J.; Berg, R. D.; Nuzzo, M.

    2013-12-01

    CRISP (Costa Rica Seismogenesis Project) is designed to investigate the processes that control fault zone behavior during earthquake nucleation and rupture propagation at erosional subduction zones. Fluids and associated diagenetic reactions are key components of this project, as they can have a profound impact on the shallow thermal structure and fluid content of the subducting and upper plates; fault zone stability and seismogenesis; and the transfer of elements and isotopes to the ocean, volcanic arc, and mantle. The pore fluid geochemistry at sites drilled in the upper and middle slope of the Costa Rica margin document fluid advection along fault zones in the upper plate, and demarcate a horizontal fluid transport zone along the discontinuity between the slope apron and underlying upper plate sediments that is continuous between Sites U1378 and U1379. Fluid flow at these sites overprints the general geochemical profiles that are influenced by in situ diagenetic reactions such as ion exchange, microbial metabolic processes, volcanic ash alteration, and carbonate diagenesis. Site U1379, drilled on the upper slope above the locked portion of the plate boundary, intersected a coarser-grained sediment interval with pervasive faulting at ~600 to 800 mbsf. Here a decrease in the concentration of Cl and of other major elements, and maxima in thermogenic hydrocarbon concentrations are observed. Based on the geothermal gradient at this site the temperature is too low to support the in situ production of thermogenic hydrocarbons or for extensive clay dehydration, thus these geochemical signals indicate a deeper source for the fluid and migration along the permeable horizons. These deep-sourced fluid signatures are even more pronounced at Sites U1378 and 1380, drilled in the middle slope, above the unlocked portion of the plate boundary. Here the horizontal transport zone is well confined to a shear zone that extends from ~480 to 550 mbsf, at the boundary between

  16. Persistent Aeolian Activity at Endeavour Crater, Mars

    Science.gov (United States)

    Chojnacki, M.; Michaels, T. I.; Fenton, L. K.

    2013-12-01

    Long-term monitoring of sites that are known to have active dunes and ripples is generally limited to 3 Mars-Years (MY). Here, we discuss new results of dune activity and albedo change in Endeavour crater (EC), Meridiani Planum (MP) that record eight MY of aeolian activity. MP dune fields often show large yearly variations in albedo; EC darkened by ~12% in TES albedo between MY 24 and 26 (from 0.14 to 0.12). THEMIS VIS albedo of dunes did not change significantly from MY 26 to 29, but did decrease notably (~15 %) in MY 30. These darkening events are most likely related to aeolian-driven dust cleaning (e.g., removal by saltating sand, dust devils). For example, the Opportunity rover (poised on the western rim of EC) observed evidence for a MY 31 dune field dust-clearing event. HiRISE monitoring of MP has shown it be one of the most active regions outside of north polar latitudes. Paired images of western EC taken 3 MY apart show clear evidence for dune modification that include: ripple migration, change in dune perimeters, exposure of previously buried light-toned rock, and/or burial of rock by sand (Fig. 1a-1b). Dune slip face movement is evident for most dunes, where crests and aprons advanced (2-7 m) in the downwind direction (to the SSE) at rates of 0.7-2.3 m per MY. Small dome dunes in the eastern EC were found to have a large degree of aeolian activity (e.g., deflation and/or translation) by an earlier study that used MGS-MRO images (MY 24-30). New MY 31 images validate earlier observations, showing clear evidence for bedform deflation where dunes often occupy less area (~50%) than in earlier MY 29 images (Fig. 1c-1d). Areal removal rates are on par with earlier estimates. Bedform modification and sand streamer orientation appear to be caused by a NNW wind regime, consistent with earlier observations, mesoscale modeling, and the transport direction of barchans to the west. Dunes in EC are now known to be periodically (consistently?) active from over a decade

  17. Development of composite materials for non-leaded glove for use in radiological hand protection

    Science.gov (United States)

    Dodoo-Amoo, David Nii Amoo

    that this new composite material could also replace the lead aprons currently in use, as shields against radiation like x-ray in most hospitals. Based on computational and experimental results, the recommended compositions of the composite materials for the glove are: (i) Erbium III Oxide (Er2O3)---40% and 40 Tungsten Boride (WB) blend with 20% Neoprene formulation, or with the reduced Er2O3, (ii) Erbium III Oxide (Er2O 3)---5% and 75% Tungsten Boride (WB) blend with 20% Neoprene formulation. (iii) Tungsten III Oxide (WO3)---80% blended with 20% Neoprene formulation. Toxicity Characteristic Leaching Procedure (TCLP) results show that, several heavy metals used in these new materials that would leach out were below the US EPA limit or are not on the list of regulated heavy metals. However, on the original gloves Lead leached out at a concentration of 5.2 mL/L, slightly above the regulatory limit.

  18. EFICIENCIA DE UN EQUIPO DE PROTECCIÓN PERSONAL PARA APLICACIONES FITOSANITARIAS EN HUERTOS FRUTALES Efficiency of a personal protection equipment for pesticide applications in orchards

    Directory of Open Access Journals (Sweden)

    S.N. Behmer

    2001-04-01

    containing permeable materials along both sides of the body and the internal arm zone. The front of the legs was protected with a waterproof apron. A dose of 40 g ha-1 of natrium fluorescein solution was applied with a pulverized air sprayer. The application rate was 2700 L ha-1 with three repetitions of 25 minutes. The global protection was 87.7% and in the zones made of permeable material the protection was 50% of the exposure. Differential protective clothing offers security and comfort to the operator and presents a high reduction of pesticide exposure, mainly in the body parts with most contamination risk during application in the orchard.

  19. Submarine Landslides at Santa Catalina Island, California

    Science.gov (United States)

    Legg, M. R.; Francis, R. D.

    2011-12-01

    Santa Catalina Island is an active tectonic block of volcanic and metamorphic rocks originally exposed during middle Miocene transtension along the evolving Pacific-North America transform plate boundary. Post-Miocene transpression created the existing large pop-up structure along the major strike-slip restraining bend of the Catalina fault that forms the southwest flank of the uplift. Prominent submerged marine terraces apparent in high-resolution bathymetric maps interrupt the steep submarine slopes in the upper ~400 meters subsea depths. Steep subaerial slopes of the island are covered by Quaternary landslides, especially at the sea cliffs and in the blueschist metamorphic rocks. The submarine slopes also show numerous landslides that range in area from a few hectares to more than three sq-km (300 hectares). Three or more landslides of recent origin exist between the nearshore and first submerged terrace along the north-facing shelf of the island's West End. One of these slides occurred during September 2005 when divers observed a remarkable change in the seafloor configuration after previous dives in the area. Near a sunken yacht at about 45-ft depth where the bottom had sloped gently into deeper water, a "sinkhole" had formed that dropped steeply to 100-ft or greater depths. Some bubbling sand was observed in the shallow water areas that may be related to the landslide process. High-resolution multibeam bathymetry acquired in 2008 by CSU Monterey Bay show this "fresh" slide and at least two other slides of varying age along the West End. The slides are each roughly 2 hectares in area and their debris aprons are spread across the first terrace at about 85-m water depth that is likely associated with the Last Glacial Maximum sealevel lowstand. Larger submarine slides exist along the steep Catalina and Catalina Ridge escarpments along the southwest flank of the island platform. A prominent slide block, exceeding 3 sq-km in area, appears to have slipped more than

  20. Condições de radioproteção dos consultórios odontológicos Radioprotection in dentistry offices

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Batista de Melo

    2008-12-01

    Aracaju using radiographic examination as a routine, resulting in a final sample of 103 professionals. The results showed that a high percentage of these professionals ignore the current norms (64,1% as well as the technical specifications of their equipment (51,5% ignored the peak kilovoltage and 57,3% the milliamperage of their equipment, besides examining the radiographs visually (67% As positive behaviors, the paralleling technique was preferred by 62,1% and the lead apron was used by 98,1%. We conclude that, despite the limited knowledge about the Guidelines, some measures are being correctly adopted but that the dentists have to be more aware of the necessary protective measures.

  1. Levantamento das condições de funcionamento dos serviços de radiologia de hospitais públicos e universitários do Rio de Janeiro Evaluation of working conditions of radiology departments of public and university hospitals in Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Marcos Otaviano da Silva

    2004-08-01

    percentages of disapprovement were: for the HVL (half-value layer 30%, for beam alignment 18%, for field coincidence 30%, for exposure linearity 40% and for focal spot 64%. It has also been observed that frequently the lead aprons were not kept in appropriate hangers and this procedure may cause damage to these accessories. The results of the test suggest the need of implementation of quality assurance tests in these services. The cost benefit analysis of the results reinforces the importance of the implementation of the recommendations contained in this paper.

  2. Technical developments in uranium mining and milling in India

    International Nuclear Information System (INIS)

    Full text: Uranium mining in India made a formal beginning with formation of Uranium Corporation of India Ltd. in October 1967. In accordance with the mandate of producing and meeting the uranium requirement of the country, UCIL has continuously upgraded the technology and operating practices with regard to its core activities - uranium ore mining, processing and disposal of tailings. Jaduguda underground mine in Singhbhum east district of Jharkhand (Eastern India) was commissioned in 1968. Regular mining operations started with the sinking of a fully lined vertical shaft and equipping the same with two winders which support a cage and a skip. This was followed by commissioning of Bhatin mine in 1986, Narwapahar mine in 1995, Turamdih mine in 2003, and Bagjata mine in 2008. New mines adopt decline method of entry and use of track less equipment in cut-and fill method of stoping. Vertical shafts provide access to deeper levels for ore and men and material hoisting. Banduhurang, the first open cast uranium mine of the country was commissioned in Jan 2009. New mine at Tummalapalle in Andhra Pradesh and underground mine at Mohuldih in Jharkhand are under construction. The mine at Tummalapalle has been planned with three declines along the apparent dip of the orebody and breast stoping method using trackless equipment. At Lambapur-Peddagattu in Andhra Pradesh, room and pillar method of stoping is proposed for underground mines with deployment of low profile drilling and loading-dumping equipment. The conventional way of processing of uranium ore in India is through hydro-metallurgical route followed by acid leaching and MDU precipitation. Jaduguda plant commissioned in 1968 has been expanded in two phases and 3rd phase expansion is underway. The plant at Turamdih encompasses new equipment and monitoring systems like apron feeder, horizontal belt filter, high rate thickener, particle size monitor etc. Both Jaduguda and Turamdih plants are designed to produce magnesium

  3. Hygiene aspects of cosmetic services

    Directory of Open Access Journals (Sweden)

    Anita Kukułowicz

    2016-03-01

    epidermidis was observed and present in more than 30% of bowls for soaking feet and on the hands of beauticians in over 60% of the samples. 2 All tested areas were marked by the presence of fungi and yeasts, and a number of aerobic, mesophilic microorganisms. 3 Among the analyzed surfaces, the most contaminated were bowls for soaking feet. 4 The most contaminated with the mesophilic bacteria were samples taken from the hands of beauticians, of which almost 70% obtained only sufficient score; more than 30% of samples taken from the surfaces of aprons obtained the same score. 5 Nearly 20% of samples taken from towels received the excelled grade, depending on the total number of microorganisms, while the very good grade was given to 50% of tests taken from the covers of the chair used for face treatments and, again, to 50% of samples from towels.

  4. Establishing aeolian particulate 'fingerprints' in an airport environment using magnetic measurements and SEM/EDAX

    Science.gov (United States)

    Jones, Sue; Hoon, Stephen R.; Richardson, Nigel; Bennett, Michael

    2016-04-01

    The significant increase in global air travel which has occurred during the last fifty years has generated growing concern regarding the potential impacts associated with increasing emissions of particulate matter (PM) from aviation activity on health and the environment. PM within the airport environment, in particular, may be derived from a wide range of potential sources including aircraft; vehicles; ground support equipment and buildings. In order to investigate and remediate potential problem sources, it is important to be able to identify characteristic particulate 'fingerprints' which would allow source attribution, particularly respirable particulates. To date the identification of such 'fingerprints' has remained elusive but remains a key research priority for the aviation industry (Webb et al, 2008). In previous PM studies, environmental magnetism has been used as a successful technique for discriminating between different emission types and particulate sources in both urban and industrial environments (e.g. Hunt et al 1984; Lecoanet et al 2003, Jones et al 2015). Environmental magnetism is a non-destructive and relatively rapid technique involving the use of non-directional, rock magnetic measurements to characterise the mineral magnetic properties of natural and anthropogenic materials. In other studies scanning electron microscopy (SEM) has also been used as an effective characterisation technique for the investigation of grain size and morphology of PM derived from vehicle emissions (e.g. Bucko et al 2010) and fossil fuel combustion sources (Kim et al 2009). In this study, environmental magnetic measurements and SEM/EDAX have been used to characterise dusts from specific aircraft sources including engines, brakes and tyres. Furthermore, these methods have also been applied to runway (both hard and grass covered surfaces), taxiway and apron dusts collected during extensive environmental sampling at Manchester International Airport, UK in order to

  5. Volcaniclastic stratigraphy of Gede volcano in West Java

    Science.gov (United States)

    Belousov, A.; Belousova, M.; Zaennudin, A.; Prambada, O.

    2012-12-01

    Gede volcano (2958 m a.s.l.) and the adjacent Pangrango volcano (3019 m a.s.l.) form large (base diameter 35 km) volcanic massif 60 km south of Jakarta. While Pangrango has no recorded eruptions, Gede is one of the most active volcanoes in Indonesia: eruptions were reported 26 times starting from 1747 (Petroeschevsky 1943; van Bemmelen 1949). Historic eruptions were mildly explosive (Vulcanian) with at least one lava flow. Modern activity of the volcano includes persistent solfataric activity in the summit crater and periodic seismic swarms - in 1990, 1991, 1992, 1995, 1996, 1997, 2000, 2010, and 2012 (CVGHM). Lands around the Gede-Pangrango massif are densely populated with villages up to 1500-2000 m a.s.l. Higher, the volcano is covered by rain forest of the Gede-Pangrango Natural Park, which is visited every day by numerous tourists who camp in the summit area. We report the results of the detailed reinvestigation of volcaniclastic stratigraphy of Gede volcano. This work has allowed us to obtain 24 new radiocarbon dates for the area. As a result the timing and character of activity of Gede in Holocene has been revealed. The edifice of Gede volcano consists of main stratocone (Gumuruh) with 1.8 km-wide summit caldera; intra-caldera lava cone (Gede proper) with a 900 m wide summit crater, having 2 breaches toward N-NE; and intra-crater infill (lava dome/flow capped with 3 small craters surrounded by pyroclastic aprons). The Gumuruh edifice, composed mostly of lava flows, comprises more than 90% of the total volume of the volcano. Deep weathering of rocks and thick (2-4 m) red laterite soil covering Gumuruh indicates its very old age. Attempts to get 14C dates in 4 different locations of Gumuruh (including a large debris avalanche deposit on its SE foot) provided ages older than 45,000 years - beyond the limit for 14C dating. Outside the summit caldera, notable volumes of fresh, 14C datable volcaniclastic deposits were found only in the NNE sector of the volcano

  6. The stratigraphy of cretaceous mudstones in the eastern Fuegian Andes: new data from body and trace fossils Estratigrafía de las fangolitas del Cretácico en los Andes Fueguinos orientales: Nuevos datos de cuerpos y trazas fósiles

    Directory of Open Access Journals (Sweden)

    Eduardo B. Olivero

    2009-04-01

    Full Text Available The stratigraphy of Cretaceous marine mudstones in the Fuegian Andes, roughly equivalent to Charles Darwin's clay-slate formation, remains a still unsolved problem. Previous records of Albian, Turonian-Coniacian, and Santonian-Campanian bivalves are combined with new findings of the Late Albian inoceramid Inoceramus anglicus Woods, and the Maastrichtian ammonites Diplomoceras sp., Anagaudryceras sp., Maorites densicostatus (Kilian and Reboul, Maorites sp., and Pachydiscus (Neodesmoceras sp. to further constrain the Cretaceous stratigraphy of the eastern Fuegian Andes. In addition, new records of distinctive trace fossils and ichnofabric are meaningful for stratigraphic division and delineation of paleoenvironmental settings in these Cretaceous mudstones. The Lower Cretaceous ichnoassemblage of Chondrites targioni (Brongniart and Zoophycos isp. is consistent with the inferred slope-volcaniclastic apron settings of the Yahgan Formation; Nereites missouriensis (Weller reflects distal basin plain depositional settings for the Beauvoir Formation. In the Upper Cretaceous, the "Estratos de Buen Suceso" record the earliest extensively bioturbated horizons, reflecting prolonged well-oxygenated bottom conditions. In the Bahía Thetis Formation, organic-rich, channel margin or distal basin slaty mudstones record the last occurrence of inoceramid bivalves in the Austral Basin; the generalized absence of trace fossils is consistent with dysoxic bottom conditions. The thoroughly bioturbated Policarpo Formation, records a marked change in paleoceanographic conditions. The strong contrast in the intensity of bioturbation between the Upper Campanian-Maastrichtian Bahía Thetis Formation, almost devoid of trace fossils, and the highly bioturbated Maastrichtian-Danian Policarpo Formation reflects a change from dysoxic-anoxic to well ventilated conditions, probably associated with a cooling trend of bottom waters in the austral deep oceans.En los Andes Fueguinos la

  7. Risk of Hematopoietic and Lymphoproliferative Malignancies among U. S. Radiologic Technologists

    Energy Technology Data Exchange (ETDEWEB)

    Linet, M. S.; Fredman, D. M.; Mohan, A.; Morin Doody, M.; Ron, E.; Mabuchi, K.; Alexander, B. B.; Sigurdson, A.; Matanoski, G.; Hauptmann, M.

    2004-07-01

    before 1950 (p=0.04). A five-fold excess risk was observed for technologists working five or more years prior to 1950, compared with those who worked after 1950. None of the other hematopoietic or lymphoproliferative neoplasms were associated with the number of years technologists worked either before or after 1950. Technologies ts who reported holding patients for x-rays 50 or more times had a 2,6-fold significantly elevated risk of developing a radiogenic leukemia, but no excesses of other types of hematopoietic or lymphoproliferative neoplasms. Risks of hematopoietic or lymphoproliferative malignancies were not modified by age at first exposure, and not related to personal radiotherapy, lack of use of lead aprons, or allowing others to take practice x-rays on them. The observed associations for radiogenic leukemia with the number of years technologists worked before 1950 (when radiation exposures were high) and with holding patients for x-rays 50 or more times, and the lack of association of chronic lymphocyte leukemia, multiple myeloma, non-Hodgkin lymphoma, and Hodgkin lymphoma with work-related radiation exposures is consistent with radiation-related risks similar for findings observed in previous studies of medical and other radiation workers. (Author)

  8. Launch Pad in a Box

    Science.gov (United States)

    Mantovani, J. G.; Tamasy, G. J.; Mueller, R. P.; Townsend, I. I.; Sampson, J. W.; Lane, M. A.

    2016-01-01

    . The thermal energy from the Morpheus rocket exhaust plume was only found to be sufficient to cause appreciable ablation of one of the four ablatives that were tested. The rocket exhaust plume did cause spalling of concrete during each descent and landing on a landing pad in the hazard field. The Extended Abstract ASE Earth and Space Conference April, 2016 - Orlando, FL concrete surface was laser scanned following each Morpheus landing, and the total volume of spalled concrete that eroded between the first and final landings of the Morpheus Project's test campaign was estimated. This paper will also describe a new deployable launch system (DLS) capability that is being developed at KSC and was publicly announced in May 2015 (KSC Partnerships, 2015). The DLS is a set of multi-user Ground Support Equipment that will be used to test and launch small class launch vehicles. The system is comprised of four main elements: the Launch Stand, the Flame Deflector, the Pad Apron and the KAMAG transporter. The system elements are designed to be deployed at launch or test sites within the KSC/CCAFS boundaries. The DLS is intended to be used together with the Fluid and Electrical System of the Universal Propellant Servicing Systems and Mobile Power Data and Communications Unit.

  9. Occupational doses in interventional cardiology: Experiences in obtaining worldwide data as part of the ISEMIR project

    International Nuclear Information System (INIS)

    ''contaminated'' with doses from other occupational classes or functions, such as interventional radiology; corrected and uncorrected doses were mixed in the same database; reported doses were from a database that contained only doses above some action level. Occupational dose data from 29 countries were analyzed giving results that included: - For those RBs reporting data for IC physicians as a group, in 2008 the mean country median effective dose was 0.73±0.62 mSv per year, and the mean country 3rd quartile effective dose was 1.09±0.69 mSv per year. The 2008 results are based on reported monitoring results from 23 countries, for a total of 1432 interventional cardiology physicians; - For those RBs reporting data for other professionals in IC as a group, in 2008 the mean country median effective dose was 0.76±0.68 mSv per year, and the mean country 3rd quartile effective dose was 1.10±1.09 mSv per year. The 2008 results are based on reported monitoring results from 17 countries, for a total of 825 other professionals working in IC. While on the one hand, all the reported annual effective doses were well below the 20 mSv occupational dose limit, recommended by the ICRP, on the other they were lower than expected when compared with validated data from facility-specific studies. It is likely that the largest potential shortcoming of the reported results is the uncertainty of whether dosimeters were actually worn by the interventional cardiologists whenever they were performing IC procedures. Reasons for non- compliance with monitoring range from simple negligence to deliberate avoidance because of the fear of exceeding some dose threshold that leads to regulatory or administrative investigation (often as a result of an above-the-apron dose value being used as a surrogate for effective dose with no correction factor used)

  10. SHARAD, the SHAllow RADar on board the MRO mission: a new insight into Mars

    Science.gov (United States)

    Seu, Roberto

    SHARAD is a subsurface sounding radar, ASI (Italian Space Agency) facility instrument on board the NASA Mars Reconnaissance Orbiter (MRO) mission. It has been designed, devel-oped and it is now operated by a joint Sapienza University of Rome and Thales Alenia Space Italy team under different Italian Space Agency (ASI) contracts. The primary objective of the SHARAD experiment is to map, in selected locales, dielectric interfaces in the martian sub-surface and to interpret these results in terms of the occurrence and distribution of expected materials, including competent rock, regolith, water and ice. To meet this objective SHARAD transmits a linear frequency modulated waveform of 10 MHz bandwidth, which allows 15 m of range resolution in free space, on a carrier frequency of 20 MHz, which in practice does allow a penetration depth of up to a kilometer or more, depending on the nature of the subsurface material. The ground resolution is on the order of 300 m along-track, achieved by means of an advanced synthetic aperture processing, and about 3 km across-track. With these char-acteristics and performance SHARAD has provided the science team with a large number of radargrams with high SNR as it observes selected science targets. The scientific results achieved analyzing the data collected by SHARAD are described in several papers published in different international journals. A few science highlights are summarized in the following. Martian sur-face features identified as lobate debris aprons (LDAs) are thick (100s of m) masses of material that extend up to several 10s of km from high relief slopes and terminate in lobate fronts. Their geomorphic expression and restricted occurrence in latitude has led numerous workers to conclude that LDAs contain water ice, but the suggested amount of ice involved in their forma-tion and evolution has ranged from minor interstitial ice in rocky talus to predominantly ice in debris-covered glaciers. SHARAD data have provided

  11. Methicillin-resistant Staphylococcus aureus on surfaces of an Intensive Care Unit Staphylococcus aureus resistente a la meticilina en superfícies de una Unidad de Cuidados Intensivos Staphylococcus aureus resistente à meticilina em superfícies de uma Unidade de Terapia Intensiva

    Directory of Open Access Journals (Sweden)

    Adriano Menis Ferreira

    2011-01-01

    Full Text Available OBJECTIVE: To evaluate the presence of methicillin-resistant Staphylococcus aureus (MRSA in areas close to patients in a General Intensive Care Unit. METHODS: This is a cross-sectional study, in which microbiological samples were collected from five surfaces (left / right bed siderails, bed crank, table, buttons on the infusion pump, and cotton gowns from each of ten patient rooms, totaling 63 samples. To collect samples, the Petri FilmTM Staph Express Count System 3M TM was used to screen for methicillin resistance, with the Mueller-Hinton agar supplemented with 4% sodium chloride and 6 µg / ml of oxacillin. Descriptive analysis was conducted to determine the frequency (n and percentage (% of contamination of environmental surfaces. RESULTS: Of 48 samples positive for Staphylococcus aureus, 29 (60.4% were resistant to methicillin. The incidence on the siderails and bed cranks, table, buttons on the infusion pumps and aprons were, respectively, 55.5%, 57.1%, 57.1%, 60.0% and 75.0%. CONCLUSION: The results suggest that the surfaces around the patient constitute a major threat, as they represent secondary reservoirs of MRSA.OBJETIVO: Evaluar la presencia de Staphylococcus aureus resistente a la meticilina (MRSA en superficies cercanas a los pacientes internados en una Unidad de Cuidados Intensivos General. MÉTODOS: Se trata de un estudio transversal, en el cual se recolectaron muestras microbiológicas de cinco superficies (enrejados derecho/izquierdo, manivela de la cama, mesa, botones de la bomba de infusión y mandiles de algodón de cada diez unidades de pacientes, totalizando 63 muestras. Para la recolección, se utilizaron placas Petri FilmTM Staph Express Count System 3M TM y para el triaje de resistencia a la meticilina, el agar Mueller-Hinton adicionado del 4% de cloruro de sodio y 6 µg/ml oxacilina. Se emplearon análisis descriptivos para determinar la frecuencia (n y el porcentaje (% de contaminación de las superficies ambientales

  12. SHARAD, the SHAllow RADar on board the MRO mission: a new insight into Mars

    Science.gov (United States)

    Seu, Roberto

    SHARAD is a subsurface sounding radar, ASI (Italian Space Agency) facility instrument on board the NASA Mars Reconnaissance Orbiter (MRO) mission. It has been designed, devel-oped and it is now operated by a joint Sapienza University of Rome and Thales Alenia Space Italy team under different Italian Space Agency (ASI) contracts. The primary objective of the SHARAD experiment is to map, in selected locales, dielectric interfaces in the martian sub-surface and to interpret these results in terms of the occurrence and distribution of expected materials, including competent rock, regolith, water and ice. To meet this objective SHARAD transmits a linear frequency modulated waveform of 10 MHz bandwidth, which allows 15 m of range resolution in free space, on a carrier frequency of 20 MHz, which in practice does allow a penetration depth of up to a kilometer or more, depending on the nature of the subsurface material. The ground resolution is on the order of 300 m along-track, achieved by means of an advanced synthetic aperture processing, and about 3 km across-track. With these char-acteristics and performance SHARAD has provided the science team with a large number of radargrams with high SNR as it observes selected science targets. The scientific results achieved analyzing the data collected by SHARAD are described in several papers published in different international journals. A few science highlights are summarized in the following. Martian sur-face features identified as lobate debris aprons (LDAs) are thick (100s of m) masses of material that extend up to several 10s of km from high relief slopes and terminate in lobate fronts. Their geomorphic expression and restricted occurrence in latitude has led numerous workers to conclude that LDAs contain water ice, but the suggested amount of ice involved in their forma-tion and evolution has ranged from minor interstitial ice in rocky talus to predominantly ice in debris-covered glaciers. SHARAD data have provided

  13. 新疆某现代化肉牛屠宰加工过程中肠杆菌科细菌的检测研究%Detection of Enterobacteriaceae in a Beef Cattle Slaughtering and Processing Plant in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    堵舒桐; 彭斌; 王金泉; 张晓红; 马玉辉; 姚刚; 王志琴

    2015-01-01

    【目的】肠杆菌科细菌作为食品卫生指标菌较大肠菌群等指标菌更敏感,更准确,有着更重要的公共卫生学意义。检测新疆某现代化肉牛屠宰加工过程中肠杆菌科细菌,为有效对生产加工环节的风险关键点加以控制提供科学依据。【方法】参照 SN ∕T 0738—1997中的肠杆菌科细菌检测方法,对新疆某现代化屠宰厂屠宰﹑分割全过程中牛胴体表面及修整人员手﹑刀具﹑围裙,修整操作台及传输带等环节肠杆菌科细菌的污染状况进行检测分析。【结果】冲洗工序可使肠杆菌科细菌从1.64 log cfu∕cm2极显著降低到1.27 log cfu∕cm2(P ﹤0.01),经排酸后又极显著升高到2.46 log cfu∕cm2,分割肉表面的肠杆菌科细菌为3.55 log cfu∕cm2,极显著高于分割前(P ﹤0.01)。在分割环节中尤以修整工人的围裙和修整操作台污染较重。【结论】该肉牛屠宰加工企业存在一定的肠杆菌科细菌污染隐患,应将排酸环节,分割环节中修整工人围裙和修整操作台作为肠杆菌科细菌污染的主要风险关键点加以监控。%Objective] Enterobacteriaceae bacteria as an indicator for food hygienic situation are more sensitive and accurate than coliform bacteria,which have more important meaning for public health,therefore, through the detection of a modern beef slaughtering and processing process of Enterobacteriaceae bacteria,we can effectively control the key risk points during the whole processing procedures.[Method]In this study the enterobacteriaceae bacteria on beef carcass,splitting facilities and workers ′hands and aprons in a modern slaughterhouse in Xinjiang were detected according to the method stipulated in SN ∕T 0738 —1997.[Result]The result showed that after carcass washing process,the enterobacteriaceae bacteria were reduced significantly from 1.64 log cfu ∕cm2 to 1.27 log cfu ∕cm2 (P ﹤0.01).however,they were increased extremly to 2.46 log cfu

  14. Noctis Landing: A Proposed Landing Site/Exploration Zone for Human Missions to the Surface of Mars

    Science.gov (United States)

    Lee, Pascal; Acedillo, Shannen; Braham, Stephen; Brown, Adrian; Elphic, Richard; Fong, Terry; Glass, Brian; Hoftun, Christopher; Johansen, Brage W.; Lorber, Kira; Mittlefehldt, David; Takagi, Yuta; Thomas, Peter; West, Michael; West, Stephen; Zolensky, Michael

    2015-01-01

    The proposed Noctis Landing Site/Exploration Zone (LS/EZ) is shown in Figure 1. Our preliminary study suggests that the proposed site meets all key Science and Resources (incl. Civil Engineering) requirements. The site is of significant interest, as the EZ not only offers a large number and wide range of regions of interest (ROIs) for short-term exploration, it is also located strategically at the crossroads between Tharsis and Valles Marineris, which are key for long-term exploration. The proposed site contains Regions of Interest (ROIs) that meet the following Science requirements: -­- Access to (1) deposits with a high preservation potential for evidence of past habitability and fossil biosignatures and (2) sites that are promising for present habitability. The site presents a wide variety of ROIs qith likely aqueous features and deposits, including sinous channels and valleys, slope gullies, lobate debris aprons, impact craters with lobate ejecta flows, and "bathtub ring" deposits. Neutron spectrometry also suggests hydrogen is present within the topmost 0.3 m or so of 4 to 10 wt% WEH (Water Equivalent Hydrogen). -­- Noachian and/or Hesperian rocks in a stratigraphic context that have a high likelihood of containing trapped atmospheric gases. Collapsed canyon rim material with preserved stratigraphy is abundantly present and accessible. -­- Exposures of at least two crustal units that have regional or global extents, that are suitable for radiometric dating, and that have relative ages that sample a significant range of martian geological time. Canyons floors in Ius Chasma, Tithonium Chasma, and plateau tops on Tharsis and in Sinai Planum offer access to distinct crustal units of regional extent. -­- Access to outcrops with linked morphological and/or geochemical signatures indicative of aqueous or groundwater/ mineral interactions. Iron and sulfur-bearing deposits on canyon floors in Noctis Labyrinthus, and in Ius Chasma (IC) and Tithonium Chasma (TC

  15. Synthesis of Late Cretaceous-Quaternary tectonic, sedimentary and magmatic processes and basin formation related to episodic subduction-collision in the easternmost Mediterranean region

    Science.gov (United States)

    Robertson, Alastair; Kinnaird, Timothy; McCay, Gillian; Palamakumbura, Romesh; Taslı, Kemal

    2015-04-01

    Mesozoic oceanic crust of the easternmost Mediterranean has experienced northwards subduction during Late Cretaceous-Cenozoic, either continuously or discontinuously based on kinematic evidence. Much of the existing information on sedimentation within the easternmost Mediterranean oceanic basin comes from the non-emplaced continental margins of the Levant and North Africa. In addition, sedimentary basins related to plate convergence are recorded along the northern margin of the Southern Neotethyan ocean, mainly in the Kyrenia Range of northern Cyprus and its extension into the Misis Mountains of southern Turkey, coupled with the adjacent submerged areas. In a setting of only incipient continental collision such as the easternmost Mediterranean the sedimentary basins would be expected to remain entirely submarine. In contrast, the Kyrenia Range has been strongly uplifted and subaerially exposed during Late Pliocene-Quaternary time. This allows the recognition of a number of discrete phases of sedimentary basin formation: 1. Late Cretaceous (Campanian-Maastrichtian): silicic volcanism to create a subaqueous volcaniclastic apron; 2. Maastrichtian-Paleocene: pelagic carbonate deposition interspersed with proximal gravity flows and within-plate type alkaline volcanics; 3. Early Eocene: large-scale sedimentary melange (olistostrome) emplacement; 4. Late Eocene-Late Miocene: terrigenous gravity-flow deposition in a deep-water fault dissected 'fore arc' setting. Initial, Late Eocene non-marine coarse clastic alluvial fan deposition was succeeded by Oligocene-Miocene deep-marine siliciclastic gravity flow deposits, fining and shallowing upwards during the Late Miocene; 5. Messinian: localised precipitation of evaporites in small fault-controlled basins; 6. Pliocene: shallow-marine siliciclastic-carbonate deposition in a shelf-depth, overall regressive setting; 7. Latest Pliocene to mid-Pleistocene: gravitational accumulation of coarse talus along a strongly uplifting

  16. The origin of the Dargom canal in the oasis of Samarkand (Uzbekistan). A new scenario from geoarcheological data

    Science.gov (United States)

    Marconi, V.; Mantellini, S.; Picotti, V.; Gabbianelli, G.; Tosi, M.

    2009-04-01

    As the main oases developed in the arid regions of Central Asia, the region of Samarkand is the outcome of large hydraulic works carried out since the past times. The main result of such a great landscape transformation is a complex irrigation network formed by several artificial channels and useful for both urban water supply and irrigation purposes. Within the framework of the Italo-Uzbek Archaeological Project begun in 2001, a specific study was aimed to reconstruct the history of Dargom, the primary canal on the South of the city, and its relationships with the settlement dynamics. According to the most accepted theories, the Dargom was dug during the Achaemenid Age (6th-4th c. BC) as a consequence of a master plan linked to a strong central political power. The new investigations carried out by a joined team of Archaelogists and Geologists from the University Bologna allowed a new hypothesis on the way of digging and the chronology of the Dargom itself. The analyses on the historical settlement patterns seem to suggest a low development of Samarkand's territory during the Achaemenid times, whilst the increasing of sites during the Early Middle Age (5th-8th c.) can be explained throughout the rich trades along the Silk Road as well as the development of irrigated agriculture. The present-day Dargom is a high sinuosity channel deeply incised into the bedrock flowing to the east, strongly resembling a natural channel. It has been excavated for around 70 km along an apron of alluvial fans sourced by a southern mountain range. Its morphology clearly document a natural evolution after excavation: incision and meandering took place, likely due to the increasing gradient related to the headward migration of lowering of the base-level and the decrease of the bed load through time. Field survey around the fortress of Kafir Kala, the main archeological site geographically linked to the Dargom, allowed reconstructing the original bed of the canal, marked by a layer of

  17. Contrasting Permo - Carboniferous Evolution of Resita and Sirinia - Presacina Basins (South Carpathians, Romania); an overview.

    Science.gov (United States)

    Tatu, M.; Seghedi, I.; Nutu, L. M.; Nicolae, I.

    2009-04-01

    rarely lens-like fresh water limestone. During the Permian in the Resita basin the volcanic activity was absent. In the Sirinia - Presacina basin the Lower Permian deposits are characterized by huge volcanic and volcano - sedimentary assemblages inter-fingering with red beds detritic formations. The Permian volcanism in the Sirinia - Presacina basin is dominant rhyolitic and started in subaqueous conditions. Early subaqueous domes (as isolated or as clusters) and lava flows led to the generation at their margins of huge volume of hyaloclastic breccias that turn unstable forming marginally turbiditic hyaloclastite aprons. In the Sirinia zone, where the magmas get to the shallower waters and/or to subaerial, the volcanic activity turned progressively to be explosive, generating phreatomagmatic eruptions. The result of this activity is up to several hundred meters of various deposits represented by pyroclastic flow (dominantly non-welded and welded ignimbrites), pyroclastic surge and fall out, all rich in accretionary lapilli. At the distal, marginal part of the volcanic environs the epiclastic, mostly lahar deposits are dominating, sometimes including layers of fallout deposits with accretionary lapilli that suggest their contemporaneous deposition. In the eastern part of Sirinia - Presacina basin (Cucuiova Hill) the presence of basalts as sills in the Permian sandstone deposits may be a sign of bimodal magmatic activity. As in the some of the Central Europe Permian basins the volcanic activity from Sirinia - Presacina basin is related to intra-basinal active faults and in particular with the intersection of fault systems having a pull-apart features (e.g. Stollhofen et al., 1999). The most important factor which was controlled the Permo - Carboniferous complex evolution of the Western and Central Europe was tectonic. The continue convergence between Laurasia and Gondwana during the Upper Carboniferous - Lower Permian (Ziegler, 1990) was generated a conjugate dextral

  18. Design and Development of System Platform of “Study on Relationship between Natural Phenology and Climate Change” Based on WEB and GIS%基于WEB和GIS的“自然物候与气候变化关系的研究”系统平台的设计与开发

    Institute of Scientific and Technical Information of China (English)

    史彩霞; 李耀先; 李莉; 黄梅丽; 邓英姿

    2012-01-01

    [Objective] The research aimed to study design and development of system platform of "study on relationship between natural phenology and climate change" based on WEB and GIS. [ Method] Relied on the technologies of WEB and CIS, the system platform of "study on relationship between natural phenology and climate change" was developed based on the hybrid architecture of C/S (Client/Server) and B/S (Brower/Server). Moreover, its build process and functional module were detailedly introduced. [Result] The natural phenology and climate change in Guangxi were research objects of system platform of "study on relationship between natural phenology and climate change". By combining WEB and GIS with database, the primary application of research about relationship between natural phenology and climate change was realized. The system used hybrid architecture of C/S and B/S. The four layers of architecture were independent to improve security, stability and maintainability of system. The visual interface at the fore apron was simple, clear and easy to use. The generating program of GIS three-dimensional graph at the background was real-time and high-efficiency, providing powerful guarantee for stable and safe operation of phenology research work process. The system had functions of inquiry, analysis, statistical diagram, CIS three-dimensional graph and data export. Through the analysis of natural phenology observation data, the system could find variation rule of natural phenology as three-dimensional space (longitude, latitude and altitude) and its relationship with climate change. [ Conclusion ] The research laid good foundation for further deeply carrying out application of research about relationship between natural phenology and climate change. It also provided reference basis for recognizing nature and using change rule of phenology to execute production scheduling and strategic decision (seed-introdurtion and regionalization).%[目的]研究基于WEB和GIS的“自然

  19. Evolution of a dynamic paleo-hydrothermal system at Mangatete, Taupo Volcanic Zone, New Zealand

    Science.gov (United States)

    Drake, Bryan D.; Campbell, Kathleen A.; Rowland, Julie V.; Guido, Diego M.; Browne, Patrick R. L.; Rae, Andrew

    2014-08-01

    Recent quarrying and active faulting at Mangatete, Taupo Volcanic Zone (TVZ), New Zealand, illuminate a rare spatial and temporal window on a dynamic Late Quaternary geothermal system. Detailed geological mapping, stratigraphic logging, AMS 14C dating, and textural and mineralogical analyses were used to construct a complex history of hydrothermal, volcanological and tectonic activity from ~ 36 to 2 ka. Extinct, surface hydrothermal manifestations occur over a ~ 2 km2 area, and include in situ siliceous sinters distributed on normal fault terraces, an inferred hydrothermal eruption breccia (HEB) containing acid-etched sinter blocks, another probable HEB that was bathed in silicifying thermal fluids, and sinter clasts that were entrained in a debris flow associated with a volcanic ash event. Preserved sinter textures typical of near-neutral pH, alkali chloride spring discharge channels, aprons, terraces and affiliated marshes comprise plant-rich, palisade, tufted bubble mat, and domal stromatolitic fabrics. In addition, a packed fragmental sinter facies is shown herein to constitute silicified microbial mats that were broken, transported and deposited as point bar deposits in thermal spring-fed streams. Moreover, four unusual siliceous sinter fabrics-vuggy, globular spongy, scalloped, and arcuate wavy layered-are interpreted to have formed from local acid-sulfate-chloride thermal springs, possibly associated with paleo-fumaroles. The reconstructed history of paleo-hydrothermal activity indicates that the oldest sinters (~ 36 ka) at Mangatete developed in alkali chloride hot springs, but then underwent post-depositional alterion/overprinting by acid-sulfate steam condensate and were dismembered, possibly by a hydrothermal eruption. Low pH hot-spring discharges forming the unusual, inferred acid sinter fabrics were localized in the same area. A shift in paleo-hydrology is evidenced by unaltered, alkali chloride sinters dated between ~ 22 and 3 ka. A cluster of sinter

  20. Kilometer-thick ice-sheets in the northern mid-latitudes of Mars in the Amazonian: Analogs from the East Antarctic Ice Sheet and the Dry Valleys

    Science.gov (United States)

    Head, James W.; Marchant, David R.

    2008-09-01

    tundra biota and wet-based alpine glaciation) to today's cold and dry conditions in which sublimation, as opposed to melting, dominates ice recession. A modern-day counterpart for the initial phase of icesheet recession during the late Miocene is still observed in areas where small tributary glaciers feed main trunk glaciers (Fig. 2) and where subtle oscillations in ice margins produce multiple drop moraines. Ultimately, during the final stages of glacial overriding, alpine glaciers formed in the lee of emerging nunatacks and at the head of steep alcoves (Figs. 1-2). The alpine glaciers were likely fed from direct precipitation and from wind-blown snow off the surface of diminishing plateau ice caps. As ice recession progressed, ever-larger exposures of bedrock were likely revealed; in areas of steep bedrock scarps, rockfall covered glaciers below, and/or became trapped as englacial debris. This rockfall, along with continued ice sublimation, produced classic debris-covered glaciers (Fig. 3), some of which may still survive to this day along the flanks of the major bedrock escarpments (with subsurface ice being > 8.1 Ma) [14]. Although simplified, the above scenario documents nicely the notion that current debriscovered glaciers in the ADV are remnants of a much larger glacial landsystem. By understanding the sequence of events of the full ADV landsystem, not just the remnant ice-rich deposits, we may better frame pertinent questions regarding the potential advance, retreat and distribution of glacier ice across the martian dichotomy boundary. Glacial deposits along the dichotomy boundary: Lineated valley fill (LVF) and lobate debris aprons (LDA) in fretted valleys at the dichotomy boundary have been interpreted as glacial in origin [10] formed during periods of higher obliquity [9]. Unknown have been 1) the original thickness of the glacier ice, and 2) the amount of ice-surface lowering, through sublimation, retreat and ice loss, to its presently observed level. We

  1. Research on the Distribution and Characteristics of Moso Ethnic Costume during the Ming and Qing Dynasties

    Institute of Scientific and Technical Information of China (English)

    YANG Linjun

    2014-01-01

    Chinese .The women's costume , while keeping the traditional hair style and sheep skin leather cape , experienced some changes in accordance with Han and Mongo-lian costume . Therefore , the women started to wear long gowns, trousers, pleated aprons, and the very typical “seven -star cape”. In the Yongning -Yanyuan area , the traditional Moso costume, such as the long skirt , was kept, but some characteristics of Tibetan costume were also absorbed .In the areas from Beidi of Shangri -la to Eya of Muli, the characteristics of costume in the Ming dynasty were completely preserved , and only a few Tibetan costume elements were absorbed dur-ing the later period of the Qing dynasty .   Through an analysis of the geographical distri-bution and characteristics of the Moso costumes in the Ming and Qing dynasties , we can notice that the Moso costume had developed from a relatively fuzzy “far vision” to a relatively clear “close vi-sion”, and had formed three different costume cul-ture zones , which constituted the present day mul-tiple cultural pattern of the Moso ethnic costume . Seen from the perspective of the three costume zones, the characteristics of the traditional ethnic costume had been kept .However , its appearance and cultural connotations manifested very obvious changes.So, what were the factors promoting such profound change? And what caused the formation of the three different ethnic costume zones? There were many causes for the change in ethnic cos-tume , including internal and external ones .Among them, the internal causes were the key factor .The appearance of differences between the Moso ethnic costumes during the Ming and Qing dynasties were due to the following three reason   Firstly, it was closely related to the policy of the central court .In the areas, such as Lijiang , which were directly managed by the officials sent by the central government after implementation of the gaituguiliu policy ( replacement of native offi-cials with

  2. Channel geometry and discharge estimates for Dao and Niger Valles, Mars

    Science.gov (United States)

    Musiol, S.; van Gasselt, S.; Neukum, G.

    2008-09-01

    parallel to the channel margins are considered to be the result of extensional deformation. Two smoothfloored collapse depressions, representing source areas, cut into the flanks of Hadriaca Patera (Ausonia and Peraea Cavus) and are connected to Dao Vallis by a region of irregular valley floor materials. These regions are all bounded by steep scarps and are interpreted to be collapse depressions in water- or ice-rich materials. Linear and curvilinear features that are approximately parallel to the channel walls are seen in some parts of the channel floors. The channel walls show typical spur-and-gully morphology. It has been suggested that gullies can be exposed by a removal of semi-competent mantling deposits along the walls of Dao Vallis. The walls could either be a source of volatiles or provide an insulating layer [6]. A possible sedimentary deposit is observed on the floor of Hellas near the terminus of Dao Vallis [1]. Geologic evolution of the eastern rim of Hellas The oldest geologic materials result from the basin-forming impact and consist of the Noachian basin rim unit and mountainous materials. Volcanism began in the late Noachian or Early Hesperian epoch with the formation of the highland paterae. The low shields of Hadriaca and Tyrrhena Patera are interpreted to be composed primarily of pyroclastic flows. The distribution of flank materials at Hadriaca Patera can be attributed to the emplacement of gravity-driven pyroclastic flow, which is in contrast to the caldera-filling material and implies a transition from explosive to effusive volcanism at the highland paterae [5]. Substantial modification of the cratered highlands characterizes the Hesperian Period, with the formation of the smooth plateau materials, predominantly sedimentary plains-infilling low-lying intermontane areas. Continuation of this style of erosion extended into the Amazonian Period with the emplacement of debris aprons. The channels on the flanks of Hadriaca Patera are clearly truncated by