The relationship between back pain and lead apron use in radiologists

Energy Technology Data Exchange (ETDEWEB)

Moore, B.; vanSonnenberg, E.; Casola, G.; Novelline, R.A. (Department of Radiology, University of California, San Diego (Unites States))

1992-01-01

Anecdotal experience has suggested that back pain in radiologists may result from extensive wearing of lead aprons. To investigate this possibility, the authors sent questionnaires to 688 radiologists in various subspecialties whose use of lead aprons varied from none to moderate to extensive. The questionnaire included both objective items that quantitated apron use and back pain and subjective items that asked, for example, if the respondent believed that lead aprons were responsible for his or her back pain. They received 236 responses (34% response rate). Objective data from those radiologists who had experienced no back pain before wearing a lead apron (179 radiologists, 26% of those surveyed) were tabulated; respondents were grouped according to age, time spent wearing a lead apron, and degree of back pain. Odds ratios were calculated. Answers to subjective questions for all respondents were tabulated. Back pain was reported by 52% of those who estimated their lead apron use at greater than or equal to 10 hr per week, the mean response, as opposed to 46% of those who wore lead aprons fewer than 10 hr a week. These and related results were not statistically significant. Our study does not prove that wearing a lead apron is a significant risk factor for the development of back pain.

The relationship between back pain and lead apron use in radiologists

International Nuclear Information System (INIS)

Moore, B.; vanSonnenberg, E.; Casola, G.; Novelline, R.A.

1992-01-01

Anecdotal experience has suggested that back pain in radiologists may result from extensive wearing of lead aprons. To investigate this possibility, the authors sent questionnaires to 688 radiologists in various subspecialties whose use of lead aprons varied from none to moderate to extensive. The questionnaire included both objective items that quantitated apron use and back pain and subjective items that asked, for example, if the respondent believed that lead aprons were responsible for his or her back pain. They received 236 responses (34% response rate). Objective data from those radiologists who had experienced no back pain before wearing a lead apron (179 radiologists, 26% of those surveyed) were tabulated; respondents were grouped according to age, time spent wearing a lead apron, and degree of back pain. Odds ratios were calculated. Answers to subjective questions for all respondents were tabulated. Back pain was reported by 52% of those who estimated their lead apron use at greater than or equal to 10 hr per week, the mean response, as opposed to 46% of those who wore lead aprons fewer than 10 hr a week. These and related results were not statistically significant. Our study does not prove that wearing a lead apron is a significant risk factor for the development of back pain

Integrity test of lead apron and its effect on personnel and carers

Directory of Open Access Journals (Sweden)

Omojola Akintayo Daniel

2018-03-01

Full Text Available The use of lead apron is known to protect radiation workers and carers (patient relatives from the scatter radiation. The study intends to assess the integrity of lead apron by checking for defects and to estimate the mean dose rate to personnel and carers and also to compare the percentage mean absorbance of the apron with the related studies. Ten lead aprons were used involving three vendors. A fluoroscopy unit, floor mounted X-ray unit, survey meter, lead aprons and meter rule were used. Crack and tear were identified with some areas close to the critical organ site. Eighty percent of the aprons showed signs that they were defective. Correlation of the lead aprons mean age and the total number of defective lead aprons were not significant (p=0.866. The mean thickness of the aprons for the three brands affected the percentage absorbance (p<0.001. The mean dose rate was above 20 mSv recommended for radiation workers averaged over a single year. It is recommended that the defective apron close to the critical organ be replaced and those in areas distal from the critical organs be further evaluated using the rejection criteria test before they are replaced.

Evaluation of radiation shielding rate of lead aprons in nuclear medicine

Energy Technology Data Exchange (ETDEWEB)

Han, Sang Hyun; Han, Beom Heui; Lee, Sang Ho [Dept. of Radiological Science, Seonam University, Asan (Korea, Republic of); Hong, Dong Heui [Dept. of Radiological Science, Far East University, Eumseong (Korea, Republic of); Kim, Gi Jin [Dept. of Nuclear Medicine, Konyang University Hospital, Daejeon (Korea, Republic of)

2017-03-15

Considering that the X-ray apron used in the department of radiology is also used in the department of nuclear medicine, the study aimed to analyze the shielding rate of the apron according to types of radioisotopes, thus γ ray energy, to investigate the protective effects. The radioisotopes used in the experiment were the top 5 nuclides in usage statistics {sup 99m}Tc, {sup 18}F, {sup 131}I, {sup 123}I, and {sup 201}Tl, and the aprons were lead equivalent 0.35 mmPb aprons currently under use in the department of nuclear medicine. As a result of experiments, average shielding rates of aprons were {sup 99m}Tc 31.59%, {sup 201}Tl 68.42%, and {sup 123}I 76.63%. When using an apron, the shielding rate of {sup 13}'1I actually resulted in average dose rate increase of 33.72%, and {sup 18}F showed an average shielding rate of –0.315%, showing there was almost no shielding effect. As a result, the radioisotopes with higher shielding rate of apron was in the descending order of {sup 123}I, {sup 201}Tl, {sup 99m}Tc, {sup 18}F, {sup 131}I. Currently, aprons used in the nuclear medicine laboratory are general X-ray aprons, and it is thought that it is not appropriate for nuclear medicine environment that utilizes γ rays. Therefore, development of nuclear medicine exclusive aprons suitable for the characteristics of radioisotopes is required in consideration of effective radiation protection and work efficiency of radiation workers.

'Do lead rubber aprons pose an infection risk?'

International Nuclear Information System (INIS)

Boyle, Helen; Strudwick, Ruth M.

2010-01-01

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 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.

Protective aprons in imaging departments: manufacturer stated lead equivalence values require validation

International Nuclear Information System (INIS)

Finnerty, M.; Brennan, P.C.

2005-01-01

The composition of protective aprons worn by X-ray personnel to shield against secondary radiation is changing. Lead is being replaced by either lead-free or composite (lead with other high atomic numbered elements) materials. These newer aprons are categorised by manufacturers in terms of lead equivalent values, but it is unclear how these stated values compare with actual lead equivalent values. In this work, the actual lead equivalence of 41 protective aprons from four manufacturers, all specified as having 0.25 mm lead equivalence, were investigated with transmission experiments at 70 and 100 kVp. All aprons were in current use. The aprons were screened for defects, and age, weight and design was recorded along with details of associated quality assurance (QA). Out of the 41 protective aprons examined for actual lead equivalence, 73% were outside tolerance levels, with actual levels in some aprons demonstrating less than half of the nominal values. The lack of compatibility between actual and nominal lead equivalent values was demonstrated by aprons from three of the four manufacturers investigated. The area of the defects found on screening of the protective aprons were within recommendations. The results highlight the need for acceptancy and ongoing checks of protective aprons to ensure that radiation exposure of imaging personnel is kept to a minimum. (orig.)

Evaluation of radiation shielding rate of lead aprons in nuclear medicine

International Nuclear Information System (INIS)

Han, Sang Hyun; Han, Beom Heui; Lee, Sang Ho; Hong, Dong Heui; Kim, Gi Jin

2017-01-01

Considering that the X-ray apron used in the department of radiology is also used in the department of nuclear medicine, the study aimed to analyze the shielding rate of the apron according to types of radioisotopes, thus γ ray energy, to investigate the protective effects. The radioisotopes used in the experiment were the top 5 nuclides in usage statistics "9"9"mTc, "1"8F, "1"3"1I, "1"2"3I, and "2"0"1Tl, and the aprons were lead equivalent 0.35 mmPb aprons currently under use in the department of nuclear medicine. As a result of experiments, average shielding rates of aprons were "9"9"mTc 31.59%, "2"0"1Tl 68.42%, and "1"2"3I 76.63%. When using an apron, the shielding rate of "1"3'1I actually resulted in average dose rate increase of 33.72%, and "1"8F showed an average shielding rate of –0.315%, showing there was almost no shielding effect. As a result, the radioisotopes with higher shielding rate of apron was in the descending order of "1"2"3I, "2"0"1Tl, "9"9"mTc, "1"8F, "1"3"1I. Currently, aprons used in the nuclear medicine laboratory are general X-ray aprons, and it is thought that it is not appropriate for nuclear medicine environment that utilizes γ rays. Therefore, development of nuclear medicine exclusive aprons suitable for the characteristics of radioisotopes is required in consideration of effective radiation protection and work efficiency of radiation workers

Study of a new X-ray protective apron with composite protective sheet

International Nuclear Information System (INIS)

Kanzaki, Ryuji; Ohtsuka, Akiyoshi; Okayama, Akio

1997-01-01

Lead powder and oxygenated lead are widely used as materials in conventional protective aprons. However, the use of lead alone limits weight reduction in an apron. Because the amount of lead can not be decreased without reducing X-ray absorption rate. In this study, we report the efficiency of a new X-ray protective apron with a composite protective sheet. The X-ray absorption rate of the composite sheet was 4.5 percent less than that of the lead sheet. However, the effective protective efficiency of the composite sheet was the same as that of the lead sheet. The uniformity of the new X-ray protective apron was good, and the differences among products were small. The new X-ray protective apron was about 30 percent lighter than a lead apron with a 0.25 mm lead equivalent. The new lighter aprons are more comfortable for the radiology staff. Therefore, the use of a composite protective apron provides the advantages of weight reduction and increased comfort without reducing X-ray absorption rate. (author)

Experimental and theoretical studies on radiation protective effect of a lighter non-lead protective apron

International Nuclear Information System (INIS)

Takano, Yoshihisa; Ono, Koji; Okazaki, Keiichiro

2005-01-01

Non-lead aprons using composite materials are often used for radiation protective aprons instead of heavy lead aprons. However, the protective effect of the lighter, non-lead aprons has not been well evaluated, and it is not yet clear how they compare with lead aprons. Therefore, we investigated the protective performance of non-lead aprons theoretically and experimentally by comparing them with lead aprons under clinical conditions. We measured the energy spectra for direct and scattered-rays passing through protective aprons or not, and measured doses with glass dosimeters for validation of theoretical calculations based on the energy spectra. We found that the protective effect of non-lead aprons was higher than that of lead aprons at X-ray of tube voltages of 70-100 kV, which are often used for radiography and fluorography. This demonstrated that the non-lead aprons are more useful in many situations than heavy lead aprons. (author)

Narrow Lead Aprons under Medical Fluoroscopy Procedures

International Nuclear Information System (INIS)

Ben-Shlomo, A.

2014-01-01

Lead aprons are the major protective item of the medical staff whose work involves x-ray exposure. Heart catheterization and angiography procedures represent the most common exposures of the medical staff. The lead equivalent thickness of lead aprons worn by the medical staff is defined by many national standards. The frontal side of the aprons should be 0.25 mm lead equivalent at working conditions under 100 kV, 0.35 mm for working conditions above 100 kV, and 0.5 mm for heart catheterization and angiography. The back side of the body needs less protection and usually is covered by 0.25 mm of lead equivalent. The lead equivalent thickness is defined at the 80 kV level

Effectiveness of lead aprons in positron emission tomography

International Nuclear Information System (INIS)

Bezerra Fonseca, R.; Amaral, A.

2008-01-01

Full text: In the last two decades, Positron Emission Tomography (PET) has emerged as clinical diagnostic technique, becoming one of the fastest growing imaging tools in modern nuclear medicine. Because 511 keV annihilation photon energy is much higher than the photon with mean energy of 140 keV emitted in Single Photon Computed Tomography (SPECT), medical staff working in PET studies receive a higher dose than those working only with SPECT tracers do. As a result, special attention must be paid to keep radiation exposure as low as reasonably achievable (ALARA principle). Lead equivalent apron is the principal personal protective equipment for technologists occupationally exposed to ionizing radiation in medical procedures and may be an important component in the ALARA program. However, in practices involving PET, 0.5 mm lead equivalent aprons have been used regardless of photon's energy. In this context, this work was designed for evaluating radioprotective effectiveness of such aprons in PET procedures. For this, the operational quantities personal dose equivalent H p (0.07) and H p (10) have been assessed by using MCNP4C code in a model of individual exposure to small source of 511 keV photons, representing the situation of injection of the radiopharmaceutical, in two situations: technologists wearing and not wearing 0.5 mm lead aprons. To represent the technologist a mathematical anthropomorphic phantom was employed, and the simulated source to subject distances varied between 40 to 100 cm, in steps of 10 cm. The results showed no significant differences between the values obtained for H p (10) in the two situations, pointing out that that there is no radioprotective influence of wearing such aprons on PET practices. Compared to simulations without such device, H p (0.07) increased up about 26% when technologist is wearing radioprotective aprons, depending on the source to subject distance. On the basis of this work, 0.5 mm lead equivalent aprons should not be

Sediment transport and mixing depth on a coral reef sand apron

Science.gov (United States)

Vila-Concejo, Ana; Harris, Daniel L.; Power, Hannah E.; Shannon, Amelia M.; Webster, Jody M.

2014-10-01

This paper investigates the mechanics of sediment transport on a subtidal sand apron located on a coral reef environment. In this environment 100% of the sediment is carbonate bioclasts generated in situ. The sand apron is located on the back reef and only affected by waves during high tides. It is commonly accepted in the literature that sand aprons are features that prograde lagoonwards and that most of the progradation occurs during high-energy events. Measurements of water depths, waves, currents and near bed suspended sediment concentrations (all at 10 Hz) on the sand apron were undertaken over a nine day intensive field campaign over both spring and neap tides; waves and tides were also measured in the lagoon. The topography and bathymetry of the sand apron were measured and mixing depth was obtained on three transects using depth of disturbance rods. We found that sediment transport on sand aprons is not solely restricted to high-energy events but occurs on a daily basis during spring tides. The main factor controlling the sediment transport was the water depth above the bed, with depths of 2-2.3 m allowing waves to promote the most sediment transport. This corresponds to a depth over the reef crest of 1.6-1.9 m. The second most important control was waves; transport was observed when Hs on the apron was 0.1 m or greater. In contrast, current magnitude was not a controlling mechanism for sediment entrainment but did affect sediment transport. The morphology of the sand apron was shown to affect the direction of currents with the currents also expected to influence the morphology of the sand apron. The currents measured during this field campaign were aligned with a shallow channel in the sand apron. Mixing depths were small (< 2.5 cm) yet they were larger than the values predicted by empirical formulae for gentle siliciclastic ocean beaches.

Lead Apron Inspection Using Infrared Light: A Model Validation Study.

Science.gov (United States)

McKenney, Sarah E; Otero, Hansel J; Fricke, Stanley T

2018-02-01

To evaluate defect detection in radiation protective apparel, typically called lead aprons, using infrared (IR) thermal imaging. The use of IR lighting eliminates the need for access to x-ray-emitting equipment and radiation dose to the inspector. The performance of radiation workers was prospectively assessed using both a tactile inspection and the IR inspection with a lead apron phantom over a 2-month period. The phantom was a modified lead apron with a series of nine holes of increasing diameter ranging from 2 to 35 mm in accordance with typical rejection criteria. Using the tactile method, a radiation worker would feel for the defects in the lead apron. For the IR inspection, a 250-W IR light source was used to illuminate the lead apron phantom; an IR camera detected the transmitted radiation. The radiation workers evaluated two stills from the IR camera. From the 31 participants inspecting the lead apron phantom with the tactile method, only 2 participants (6%) correctly discovered all 9 holes and 1 participant reported a defect that was not there; 10 of the 20 participants (50%) correctly identified all 9 holes using the IR method. Using a weighted average, 5.4 defects were detected with the tactile method and 7.5 defects were detected with the IR method. IR light can penetrate an apron's protective outer fabric and illuminate defects below the current standard rejection size criteria. The IR method improves defect detectability as compared with the tactile method. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Reducing exposure of X-ray radiodiagnosis personnel with use of apron

International Nuclear Information System (INIS)

Snobr, J.

1988-01-01

Experimental results are presented showing dose reduction in X-ray irradiation thanks to protective aprons from lead-containing rubber. The values were used to calculate a reduction in the effective dose equivalent while using the protective apron for isotropic irradiation and for frontal irradiation. A method for optimizing the lead equivalent of the protective apron is suggested. (author). 7 tabs., 6 refs

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

International Nuclear Information System (INIS)

Le Heron, J.

1997-01-01

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

Adjustable sterile lead apron for radiation protection during angiography

Energy Technology Data Exchange (ETDEWEB)

Grollman, J.H. Jr.; Sanchez, J.L.

1979-08-01

A simple sterile lead apron can be mounted directly on any vertical-beam image-intensifier housing and readjusted by the angiographer to shield himself from scatter during fluoroscopy and cineangiocardiography, even if the image intensifier is tilted in the longitudinal plane. Properly placed, the apron effectively reduces exposure due to scatter.

'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.

Usefulness of non-lead aprons in radiation protection for physicians performing interventional procedures

International Nuclear Information System (INIS)

Zuguchi, M.; Chida, K.; Taura, M.; Inaba, Y.; Ebata, A.; Yamada, S.

2008-01-01

At present, interventional radiology (IVR) tends to involve long procedures (long radiation duration), and physicians are near to the source of scattered radiation. Hence, shielding is critical in protecting physicians from radiation. Protective aprons and additional lead-shielding devices, such as table-side lead drapes, are important means of protecting the physician from scattered radiation. The purpose of this study was to evaluate whether non-lead aprons are effective in protecting physicians from radiation during IVR procedures. In this study, the radiation protection effects of commercially available protective lead and non-lead aprons, when exposed to diagnostic X rays, are compared. The performance of these non-lead and lead aprons was similar for scattered X rays at tube voltages of 60-120 kV. Properly designed non-lead aprons are thus more suitable for physicians because they weigh ∼20% less than the lead aprons, and are non-toxic. (authors)

Protective effect of lead aprons in medical radiology

International Nuclear Information System (INIS)

Huyskens, C.J.

1995-01-01

This article summarizes the results of an ongoing study regarding the protective effect that lead aprons, as used in medical radiology, have on the resulting effective dose for medical personnel. By means of model calculations we have analyzed the protection efficacy of lead aprons for various lead thicknesses, in function of tube potential and of variations in exposure geometry as they occur in practice. The degree of efficacy appears to be highly dependent on the fit of aprons because of the dominating influence of the equivalent dose of partially unshielded organs on the resulting effective dose. Also by model calculations we investigated the ratio between the effective dose and the operational quantify for personal dose monitoring. Our study enables the choice of appropriate correction factors for convering personal dosimetry measurements into effective dose, for typical exposure situations in medical radiology. (orig.) [de

Design of apron feeders

Energy Technology Data Exchange (ETDEWEB)

Ramos, C.M.

1987-12-01

This paper discusses practical aspects of apron feeder design, and includes information on how to make the first selection. Various aspects of design such as feeder speed, material depth, chain-pitch, roller loading, wheels/sprockets and chain roller friction are elaborated in detail. 8 refs., 14 figs., 12 tabs.

Effect of usual lead apron in decreasing dose rate in nuclear medicine department

Energy Technology Data Exchange (ETDEWEB)

Momennezhad, M.; Ghazikhanloo, K.; Zakavi, S.R. [Mashhad Univ. of Medical Sciences (Iran, Islamic Republic of)

2006-07-01

Full text of publication follows: Introduction: In a busy nuclear medicine department personnel exposure to radiation is inevitable during patient positioning and radiotracer preparation. There is controversy regarding usage of usual lead aprons with respect to penetrating gamma rays used in nuclear medicine departments as well as production of characteristic lead x-ray from aprons.This study tries to evaluate the effect of 0.5 mm lead apron on dose reduction. Methods and materials: We used three point sources usual radioisotopes used in nuclear medicine departments (99 mTc, 201 Tl and 131 I) and a single head L.F.O.V. gamma camera (S.M.V., D.S.X.) was used for counting purposes. The count rate for each source was about 20 K count/sec in air and in a brain water phantom. All point sources were placed at a distance of 3 meters, parallel to the center of the detector. The collimator was removed and imaging was performed for 1 min with and without lead apron on the detector. Lead apron covered all field of view of the detector. Each imaging was repeated 3 times and mean count was obtained for each radioisotope. The measurements were accomplished from full spectrum and specific region of spectrum such as characteristic lead x rays region (88 keV 20%) with and without apron. Result and Discussion: The measurement and comparison of count rates (count/min) for each source in different conditions (with and without apron source in air and in water phantom) showed that count rates were reduced in air about 77.3%, 84.2% and 40.8% for 99 mTc, 201 Tl and 131 I respectively. The reduction in count rates when sources placed in brain water phantom were 83.5%, 87% and 53.7% for the same isotope respectively. As the main source of radiation for personnel is from scattered photon and with respect to about 83% of count rate reduction using lead aprons for 99 mTc, it is expected that wearing lead apron significantly decrease dose rate. Conclusion: Our study showed that lead aprons

Effect of usual lead apron in decreasing dose rate in nuclear medicine department

International Nuclear Information System (INIS)

Momennezhad, M.; Ghazikhanloo, K.; Zakavi, S.R.

2006-01-01

Full text of publication follows: Introduction: In a busy nuclear medicine department personnel exposure to radiation is inevitable during patient positioning and radiotracer preparation. There is controversy regarding usage of usual lead aprons with respect to penetrating gamma rays used in nuclear medicine departments as well as production of characteristic lead x-ray from aprons.This study tries to evaluate the effect of 0.5 mm lead apron on dose reduction. Methods and materials: We used three point sources usual radioisotopes used in nuclear medicine departments (99 mTc, 201 Tl and 131 I) and a single head L.F.O.V. gamma camera (S.M.V., D.S.X.) was used for counting purposes. The count rate for each source was about 20 K count/sec in air and in a brain water phantom. All point sources were placed at a distance of 3 meters, parallel to the center of the detector. The collimator was removed and imaging was performed for 1 min with and without lead apron on the detector. Lead apron covered all field of view of the detector. Each imaging was repeated 3 times and mean count was obtained for each radioisotope. The measurements were accomplished from full spectrum and specific region of spectrum such as characteristic lead x rays region (88 keV 20%) with and without apron. Result and Discussion: The measurement and comparison of count rates (count/min) for each source in different conditions (with and without apron source in air and in water phantom) showed that count rates were reduced in air about 77.3%, 84.2% and 40.8% for 99 mTc, 201 Tl and 131 I respectively. The reduction in count rates when sources placed in brain water phantom were 83.5%, 87% and 53.7% for the same isotope respectively. As the main source of radiation for personnel is from scattered photon and with respect to about 83% of count rate reduction using lead aprons for 99 mTc, it is expected that wearing lead apron significantly decrease dose rate. Conclusion: Our study showed that lead aprons

Mesa with Apron

Science.gov (United States)

2006-01-01

23 September 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a mesa and an impact grater just east of Phlegra Montes. The mesa is the eroded remnant of a once more extensive terrain. An apron of material surrounds the mesa. Location near: 38.5oN, 193.4oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Spring

Dosimetric evaluation of indigenously developed non-lead bilayered radiation protective aprons

International Nuclear Information System (INIS)

Senthilkumar, S.

2018-01-01

Radiation shielding garments are commonly used to protect medical patients and radiation workers from X-radiation exposure during diagnostic imaging in hospitals. Originally, protective aprons consisted of lead-impregnated vinyl with a shielding equivalent given in millimeters of lead. All contained up to 2 mm of lead. While lead has long been used to shield patients from X-rays, its toxicity poses a health threat if the protective apron containing the metal wear out or the lead gets damaged. 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. The main purpose of this work was to indigenously develop light weight non lead based bilayered radiation protective aprons and evaluate dosimetrically with different combination of fabricated non lead materials and commercially available lead based aprons

Lead apron: room for improvement

Energy Technology Data Exchange (ETDEWEB)

Boothroyd, A.E.; Russell, J.G.B.

1987-02-01

The amount of red bone marrow not protected by a lead apron was used as an assessment of protection efficiency, and the effect of change of shape was calculated. It was concluded that change of shape would increase protection and cut down cost. (U.K.).

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

Energy Technology Data Exchange (ETDEWEB)

Syh, J; Patel, B; Syh, J; Song, X; Freund, D; Ding, X; Wu, H [Willis-Knighton Medical Center, Shreveport, LA (United States)

2015-06-15

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.

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

International Nuclear Information System (INIS)

Syh, J; Patel, B; Syh, J; Song, X; Freund, D; Ding, X; Wu, H

2015-01-01

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

Penggunaan Karet Alam pada Pembuatan Apron untuk Mesin Pemintalan

OpenAIRE

Luftinor, Luftinor

2010-01-01

The Research aims to increase the use of natural rubber in the textile industry especially is ring spinning machine, the research done by varying the amount of apron manufacture of natural rubber (SIR 20), synthetic rubber (SBR), and filler materials (carbon black) in 3 levels of each treatment each 25 phr, 50 phr and 75 phr, obtained nine kinds of rubber compounds. The nine kinds of vulcanized rubber compounds to obtain finished goods apron, next physics test. Physical properties test result...

Influence of lead apron shielding on absorbed doses from cone-beam computed tomography

International Nuclear Information System (INIS)

Rottke, Dennis; Andersson, Jonas; Ejima, Ken-Ichiro; Sawada, Kunihiko; Schulze, Dirk

2017-01-01

The aim of the present work was to investigate absorbed and to calculate effective doses (EDs) in cone-beam computed tomography (CBCT). The study was conducted using examination protocols with and without lead apron shielding. A full-body male RANDO"R phantom was loaded with 110 GR200A thermoluminescence dosemeter chips at 55 different sites and set up in two different CBCT systems (CS 9500"R, ProMax"R 3D). Two different protocols were performed: the phantom was set up (1) with and (2) without a lead apron. No statistically significant differences in organ and absorbed doses from regions outside the primary beam could be found when comparing results from exposures with and without lead apron shielding. Consequently, calculating the ED showed no significant differences between the examination protocols with and without lead apron shielding. For the ProMax"R 3D with shielding, the ED was 149 μSv, and for the examination protocol without shielding 148 μSv (SD = 0.31 μSv). For the CS 9500"R, the ED was 88 and 86 μSv (SD = 0.95 μSv), respectively, with and without lead apron shielding. The results revealed no statistically significant differences in the absorbed doses between examination with and without lead apron shielding, especially in organs outside the primary beam. (authors)

Influence on the individual dose by using lead aprons at hemodynamic services

International Nuclear Information System (INIS)

Alonso, Thessa Cristina; Silva, Teogenes Augusto da

2005-01-01

In interventional radiology, heart catheterism procedures are done with therapeutic and diagnosis purposes. In those medical practices, staff members are required to wear lead aprons for individual protection beside other protective equipment like thyroid lead protector, lead eyeglasses and gloves. The proper and suitable equipment is chosen according to the exam type. Exposure of medical team is under discussion concerned to use of the individual dosimeter under or on the lead apron and the need to apply a dose correction factor of 0.01 in the first case to estimate the effective dose. This work investigates personal doses of medical team in interventional radiology services of two hospitals in Belo Horizonte. Individual thermoluminescent dosimeters were fastened under and on lead aprons during one month period to measure the personal dose equivalents, Hp(10). Results indicate that the dose correction factor due to the lead apron presence is not a proper correction for interventional radiology exams; different factors are suggested if the worker is closer or not so close the x-ray beam. Additionally, it is emphasized that the use of adequate protective aprons and conscientious behavior according to a safety culture can minimize the radiation exposure of those professionals. (author)

SU-E-P-09: Radiation Transmission Measurements and Evaluation of Diagnostic Lead-Based and Lead-Free Aprons

Energy Technology Data Exchange (ETDEWEB)

Syh, J [Willis-Knighton Medical Center, Shreveport, LA (United States)

2014-06-01

Purpose: This study was conducted to ensure that various lead shield apron manufacturers provided accurate attenuation factors regardless of whether the apron was made of lead-based or lead-free equivalent material. Methods: A calibrated ionization survey meter was placed at chest height and 36 cm horizontally away from a solid water phantom on a simulator couch. Measurements were done with or without apron. Radiation field was set to 24cmx24cm with the phantom at 100cm source-to-surface distance. Irradiation time was set for 1 minute at voltages of 60, 80, 100 and 120 kVp. Current was set at 6mA. Results: Between 60 kVp and 120 kVp, the transmission through 0.50 mm of lead-based apron was between 1.0% and 6.5% with a mean value of 3.2% and a standard deviation (s.d.) of 1.4%. The transmissions through the 0.50 mm lead-free aprons were 1.0 % to 12.0% with a mean value of 6.1% and s.d. of 2.6%. At 120 kVp, the transmission value was 6.5% for 0.50 mm lead-based apron and 11.1% to 12.0% for 0.50 mm lead-free aprons. The radiation transmissions at 80 kVp, measured in two different 0.5 mm lead-free aprons, were 4.3% each. However, only 1.4% transmission was found through the lead-based apron. Overall, the radiation transmitted through the lead-based apron was 1/3 transmission of lead-free at 80kVp, and half value of lead-free aprons at 100 and 120 kVp. Conclusion: Even though lead-based and lead-free aprons all claimed to have the same lead equivalent thickness, the transmission might not be the same. The precaution was needed to exercise diligence in quality assurance program to assure adequate protection to staff who wear it during diagnostic procedures. The requirement for aprons not only should be in certain thickness to meet state regulation but also to keep reasonably achievable low exposure with the accurate labeling from manufacturers.

SU-E-P-09: Radiation Transmission Measurements and Evaluation of Diagnostic Lead-Based and Lead-Free Aprons

International Nuclear Information System (INIS)

Syh, J

2014-01-01

Purpose: This study was conducted to ensure that various lead shield apron manufacturers provided accurate attenuation factors regardless of whether the apron was made of lead-based or lead-free equivalent material. Methods: A calibrated ionization survey meter was placed at chest height and 36 cm horizontally away from a solid water phantom on a simulator couch. Measurements were done with or without apron. Radiation field was set to 24cmx24cm with the phantom at 100cm source-to-surface distance. Irradiation time was set for 1 minute at voltages of 60, 80, 100 and 120 kVp. Current was set at 6mA. Results: Between 60 kVp and 120 kVp, the transmission through 0.50 mm of lead-based apron was between 1.0% and 6.5% with a mean value of 3.2% and a standard deviation (s.d.) of 1.4%. The transmissions through the 0.50 mm lead-free aprons were 1.0 % to 12.0% with a mean value of 6.1% and s.d. of 2.6%. At 120 kVp, the transmission value was 6.5% for 0.50 mm lead-based apron and 11.1% to 12.0% for 0.50 mm lead-free aprons. The radiation transmissions at 80 kVp, measured in two different 0.5 mm lead-free aprons, were 4.3% each. However, only 1.4% transmission was found through the lead-based apron. Overall, the radiation transmitted through the lead-based apron was 1/3 transmission of lead-free at 80kVp, and half value of lead-free aprons at 100 and 120 kVp. Conclusion: Even though lead-based and lead-free aprons all claimed to have the same lead equivalent thickness, the transmission might not be the same. The precaution was needed to exercise diligence in quality assurance program to assure adequate protection to staff who wear it during diagnostic procedures. The requirement for aprons not only should be in certain thickness to meet state regulation but also to keep reasonably achievable low exposure with the accurate labeling from manufacturers

Influence of lead apron shielding on absorbed doses from cone-beam computed tomography.

Science.gov (United States)

Rottke, Dennis; Andersson, Jonas; Ejima, Ken-Ichiro; Sawada, Kunihiko; Schulze, Dirk

2017-06-01

The aim of the present work was to investigate absorbed and to calculate effective doses (EDs) in cone-beam computed tomography (CBCT). The study was conducted using examination protocols with and without lead apron shielding. A full-body male RANDO® phantom was loaded with 110 GR200A thermoluminescence dosemeter chips at 55 different sites and set up in two different CBCT systems (CS 9500®, ProMax® 3D). Two different protocols were performed: the phantom was set up (1) with and (2) without a lead apron. No statistically significant differences in organ and absorbed doses from regions outside the primary beam could be found when comparing results from exposures with and without lead apron shielding. Consequently, calculating the ED showed no significant differences between the examination protocols with and without lead apron shielding. For the ProMax® 3D with shielding, the ED was 149 µSv, and for the examination protocol without shielding 148 µSv (SD = 0.31 µSv). For the CS 9500®, the ED was 88 and 86 µSv (SD = 0.95 µSv), respectively, with and without lead apron shielding. The results revealed no statistically significant differences in the absorbed doses between examination with and without lead apron shielding, especially in organs outside the primary beam. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evaluasi Kebutuhan Luasan Apron Pada Rencana Pengembangan Bandar Udara Internasional Ahmad Yani Semarang

Directory of Open Access Journals (Sweden)

Muhammad Nursalim

2017-03-01

Full Text Available Bandar Udara Ahmad Yani akan memiliki terminal yang lebih luas di sebelah Utara runway, lahan parkir yang luas, apron seluas 61.344 m2 serta dua buah taxiway. Pengembangan tahap II akan menjadikan Bandar Udara Ahmad Yani memiliki apron seluas 72.522 m2 dan 10 buah taxiway serta 1 buah parallel taxiway. Studi ini akan mengevaluasi kebutuhan apron Bandar Udara internasional Ahmad Yani Semarang saat ini dan 20 tahun kedepan. Pada evaluasi ini akan diprediksi jumlah pergerakan pesawat pada tahun rencana yang kemudian akan dikonversi menjadi jumlah pesawat pada jam sibuk. Hasil prediksi jumlah pesawat ini akan dianalisis terhadap kebutuhan apron Bandar Udara Ahmad Yani di tahun rencana. Dengan adanya pengembangan apron diharapkan dapat memenuhi kebutuhan lalu lintas udara. Untuk perencanaan perkerasan apron menggunakan rigid pavement dengan metode FAA dengan software FAARFIELD. Dari hasil perhitungan didapatkan, kebutuhan total jumlah gerbang landas parkir untuk tahun rencana (2035 adalah 51 pesawat, yang terdiri dari 35 kelas C dan 16 kelas D. Selanjutnya didapatkan dimensi gerbang landas parkir pada tahun rencana (2035 adalah untuk kelas C dengan panjang 2096,50 m dan lebar 98,37 m sedangkan untuk kelas D dengan panjang 1547,20 m dan 104,78 m. Tebal perkerasan landas parkir ini adalah 670 mm. Dalam penulangan perkerasan landas parkir tahun rencana (2035 dibutuhkan wiremesh dengan D14-100 dan Dowel dengan diameter 50 mm, panjang 610 mm, dan jarak 460 mm.

Cognitive demands and the relationship between age and workload in apron control.

Science.gov (United States)

Müller, Andreas; Petru, Raluca; Angerer, Peter

2011-01-01

Apron controllers (ACs) determine the taxiways for aircraft entering the apron area until they reach their parking positions and vice versa. The aims of this study were to identify age-sensitive job requirements of apron control (Study 1), and to investigate the relationship between age of ACs and their workload (Study 2). Study 1: There were 14 experienced ACs who assessed the job requirements of apron control with the Fleishman-Job Analyses Survey. Additionally, during one shift, the number of parallel processed traffic data sets (indicating memory-load) and the number of delivered radio messages (indicating processing speed requirements) were assessed. Study 2: There were 30 ACs (age: 23-51 yr) who volunteered for trials during late shifts at an international airport. ACs assessed their subjective workload (NASA-Task Load Index) at four times during the shift and carried out an attention test (d2) before and after the shift. Moreover, their heart rate was assessed during the shift and in a reference period. Study 1: Results indicate that apron control requires especially high levels of memory-load and processing speed. Study 2: Hierarchical regression analyses revealed a u-shaped relationship between age and subjective workload (beta = 0.59) as well as heart rate (beta = 0.33). Up to the age of about 35-37 yr, workload and heart rate decreased with age, but afterwards the relationship became positive. There was no association between chronological age and attention performance. There is a need for age adequate job design in apron control that should especially aim at the reduction of memory-load and processing speed.

Assessing Doses to Interventional Radiologists Using a Personal Dosimeter Worn Over a Protective Apron

Energy Technology Data Exchange (ETDEWEB)

Stranden, E.; Widmark, A.; Sekse, T. (Buskerud Univ. College, Drammen (Norway))

2008-05-15

Background: Interventional radiologists receive significant radiation doses, and it is important to have simple methods for routine monitoring of their exposure. Purpose: To evaluate the usefulness of a dosimeter worn outside the protective apron for assessments of dose to interventional radiologists. Material and Methods: Assessments of effective dose versus dose to dosimeters worn outside the protective apron were achieved by phantom measurements. Doses outside and under the apron were assessed by phantom measurements and measurements on eight radiologists wearing two routine dosimeters for a 2-month period during ordinary working conditions. Finger doses for the same radiologists were recorded using thermoluminescent dosimeters (TLD; DXT-RAD Extremity dosimeters). Results: Typical values for the ratio between effective dose and dosimeter dose were found to be about 0.02 when the radiologist used a thyroid shield and about 0.03 without. The ratio between the dose to the dosimeter under and outside a protective apron was found to be less than 0.04. There was very good correlation between finger dose and dosimeter dose. Conclusion: A personal dosimeter worn outside a protective apron is a good screening device for dose to the eyes and fingers as well as for effective dose, even though the effective dose is grossly overestimated. Relatively high dose to the fingers and eyes remains undetected by a dosimeter worn under the apron

Assessing Doses to Interventional Radiologists Using a Personal Dosimeter Worn Over a Protective Apron

International Nuclear Information System (INIS)

Stranden, E.; Widmark, A.; Sekse, T.

2008-01-01

Background: Interventional radiologists receive significant radiation doses, and it is important to have simple methods for routine monitoring of their exposure. Purpose: To evaluate the usefulness of a dosimeter worn outside the protective apron for assessments of dose to interventional radiologists. Material and Methods: Assessments of effective dose versus dose to dosimeters worn outside the protective apron were achieved by phantom measurements. Doses outside and under the apron were assessed by phantom measurements and measurements on eight radiologists wearing two routine dosimeters for a 2-month period during ordinary working conditions. Finger doses for the same radiologists were recorded using thermoluminescent dosimeters (TLD; DXT-RAD Extremity dosimeters). Results: Typical values for the ratio between effective dose and dosimeter dose were found to be about 0.02 when the radiologist used a thyroid shield and about 0.03 without. The ratio between the dose to the dosimeter under and outside a protective apron was found to be less than 0.04. There was very good correlation between finger dose and dosimeter dose. Conclusion: A personal dosimeter worn outside a protective apron is a good screening device for dose to the eyes and fingers as well as for effective dose, even though the effective dose is grossly overestimated. Relatively high dose to the fingers and eyes remains undetected by a dosimeter worn under the apron

Mechanisms of basal ice formation in polar glaciers: An evaluation of the apron entrainment model

Science.gov (United States)

Fitzsimons, Sean; Webb, Nicola; Mager, Sarah; MacDonell, Shelley; Lorrain, Regi; Samyn, Denis

2008-06-01

Previous studies of polar glaciers have argued that basal ice can form when these glaciers override and entrain ice marginal aprons that accumulate adjacent to steep ice cliffs. To test this idea, we have studied the morphology, structure, composition, and deformation of the apron and basal ice at the terminus of Victoria Upper Glacier in the McMurdo dry valleys, which are located on the western coast of the Ross Sea at 77°S in southern Victoria Land, Antarctica. Our results show that the apron has two structural elements: an inner element that consists of strongly foliated ice that has a steep up-glacier dip, and an outer element that lacks a consistent foliation and has a down-glacier, slope-parallel dip. Although strain measurements show that the entire apron is deforming, the inner element is characterized by high strain rates, whereas relatively low rates of strain characterize the outer part of the apron. Co-isotopic analyses of the ice, together with analysis of solute chemistry and sedimentary characteristics, show that the apron is compositionally different from the basal ice. Our observations show that aprons may become deformed and partially entrained by advancing glaciers. However, such an ice marginal process does not provide a satisfactory explanation for the origin of basal ice observed at the ice margin. Our interpretation of the origin of basal ice is that it is formed by subglacial processes, which are likely to include deformation and entrainment of subglacial permafrost.

Life cycle of a geyser discharge apron: Evidence from Waikite Geyser, Whakarewarewa geothermal area, North Island, New Zealand

Science.gov (United States)

Jones, Brian; Renaut, Robin W.; Owen, R. Bernhart

2011-05-01

Waikite, a geyser located in the Whakarewarewa geothermal area on the North Island, New Zealand, has a history of eruptive-dormancy cycles that have been attributed to natural and anthropogenic causes. The last cycle involved an active period from ~ 1932 to 1968/69 that was followed by a period of dormancy that continues today. Such cycles are important because they control the temporal development of the discharge apron. When the geyser is active, growth of the discharge apron is dictated by the precipitation of opal-A, which is controlled by factors such as discharge patterns, water chemistry, pH, temperature, rate of cooling, and the resident microbiota. With dormancy, conditions change radically because water no longer flows down the discharge apron. Instead, the discharge apron lapses into a phase of degradation that, on Waikite, is evident from (1) deflation of the apron surface, (2) blocks splaying off the apron margins along margin-parallel fractures, (3) tension fractures, (4) saucer-shaped collapse zones, (5) increasingly unstable surfaces resulting from subsurface opal-A dissolution, (6) fractures, from which steam and other gases emanate, and (7) incursion of native vegetation around the edge of the apron and on the distal parts of the discharge apron. When the geyser becomes active again, silica precipitation will resume and the discharge apron will once again accrete vertically and expand laterally. Analysis of the Waikite system shows that successions that develop on geyser discharge aprons are formed of unconformity-bounded packages of sinter that reflect the eruptive-dormancy history of the parent geyser.

49 CFR 230.81 - Cab aprons.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Cab aprons. 230.81 Section 230.81 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Cabs, Warning Signals, Sanders and Lights §...

Evolution of volcaniclastic apron during initiation of Cascade volcanism in southern Oregon

Energy Technology Data Exchange (ETDEWEB)

Bestland, E.A.

1986-05-01

The Oligocene Colestin Formation consists of volcaniclastic apron sequence that records the initiation of Cascade volcanism in the western Cascade Range of southern Oregon. The formation in the type area is largely confined to an east-west-trending graben approximately 8 km wide. This graben and other smaller grabens within it developed to the west of and perpendicular to the axis of the Oligocene Cascade arc. The apron, which fills and locally overflows the graben, consists of coalesced lobes of volcaniclastic and pyroclastic deposits and lesser amounts of lava flows. Abrupt lateral facies changes on a scale of tens to hundreds of meters were produced by the lobe style of deposition and contemporaneous basin faulting. Interstratified with the discontinuous apron sediments are marker units that consist of pyroclastic flows, paleosols, and lava-flow sequences. In the upper half of the formation, the apron can be subdivided into informal members (lobes and sequences of lobes), which can be mapped according to their composition and stratigraphic position. Each member formed during a distinct interval of volcanism. An epiclastic lobe in the upper part of the formation, containing debris-flow and hyperconcentrated flood-flow deposits, represents a period of effusive or mildly explosive andesitic and basaltic volcanism. This epiclastic lobe pinches out to the south under a member that consists of tuffaceous sandstones and interbedded welded and nonwelded pyroclastic flows. The pulselike style of apron growth was produced by the episodic shifting of volcanism along the arc.

Determination of Crack Area on Lead Apron used in Diagnostic Radiology

International Nuclear Information System (INIS)

Norriza Mohd Isa; Muhammad Jamal Muhammad Isa; Asmaliza Hashim

2014-01-01

The study was performed to determine crack area of lead aprons used by personnel as radiation protector from unnecessary radiation in diagnostic radiology. The experiment was done using general X-ray and Computed Radiography (CR) systems. Calibration curve was plotted for beam quality at 80 kVp and source to detector distance (SDD) is 100 cm by selecting manual exposure mode. Lead sheet with thickness from 0.1 to 1.0 mm were used for this purpose. It was used to relate the pixel value of lead sheet images with their thickness. A few sample of lead aprons with different thickness from a hospital and our laboratories were obtained and then undergoing the inspection at our laboratory through this procedure. The samples were divided with two groups based on how long they were used which are less 10 years and more than 10 years. The images data of the sample were obtained and analysis using our developed software. The reference object with known its area was also used in the experiment to ensure our output using the software is reliable and acceptable. The results shown that lead aprons used more than 10 years have depicted more crack areas compare with the lead apron used less than 10 years. (author)

Lithofacies of deep marine basalts emplaced on a Jurassic backarc apron, Baja California (Mexico)

Energy Technology Data Exchange (ETDEWEB)

Busby-Spera, C.J.

1987-09-01

Basalts of the mid-Jurassic Gran Canon Formation, Cedros Island, Mexico, were emplaced on a volcaniclastic apron in a deep marine backarc basin. Elongate pillows and lava tubes, as well as paleocurrent data from the volcaniclastic apron, indicate a southward regional paleoslope away from the island arc source. Basalts emplaced on relatively proximal parts of the apron are nearly entirely pillowed and have thick flow units with mega-pillows. Basalts on distal parts of the apron (about 15 to 20 km down paleo-current) are dominated by pillow fragment breccias (flow foot rubble), and individual lava flows are generally thin, with small pillows, suggesting that the distal ends of lava flows, erupted upslope, are represented. These distal flow fronts, however, are interstratified with features that typically form close to a vent, including thick massive to mega-pillowed lavas and lava tubes up to 8 m in diameter. It is inferred that a fissure (or system of fissures) extended from the arc into the backarc basin, erupting basalt lavas onto both proximal and distal parts of the volcaniclastic apron. Such intraplate volcanism may be common on the hot frontal arc side of backarc basins. 26 references.

Answers to if the lead aprons are really helpful in nuclear medicine from the perspective of spectroscopy

International Nuclear Information System (INIS)

He, X.; Zhao, R.; Rong, L.; Yao, K.; Wei, B.; Chen, S.

2017-01-01

Wearing lead X-ray-protective aprons is a routine in nuclear medicine department in parts of China. However, the staff are often perplexed by questions such as if it is imperative to wear aprons when injecting radioactive drugs, how much radiation dosage can be shielded and if the apron will produce secondary radiation instead? To answer these questions, a semiconductor detector was employed to record different gamma and X-ray spectra with and without the lead apron or lead sheet. Then, we could estimate the signal shielding ratio to different photons for the lead apron and compare with the hospitals measured data. In general, the two results coincided well. The spectral results showed that the detrimental secondary X-rays irradiation rises when the energy of gamma rays exceeds the K absorption edge of lead (88 keV). Moreover, the aprons are not so effective for gamma rays of 364 keV emitted from "1"3"1I and 511 keV emitted from the positron radioactive nuclides. This work is purely a physical measurement in the laboratory. To the best of our knowledge, this is the first quantitative study on the level of gamma rays protection offered by the medical lead aprons and the importance of the spectroscopic measurements is discussed in this paper. (authors)

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

International Nuclear Information System (INIS)

Franken, Y.

2002-01-01

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

A model-based approach of scatter dose contributions and efficiency of apron shielding for radiation protection in CT.

Science.gov (United States)

Weber, N; Monnin, P; Elandoy, C; Ding, S

2015-12-01

Given the contribution of scattered radiations to patient dose in CT, apron shielding is often used for radiation protection. In this study the efficiency of apron was assessed with a model-based approach of the contributions of the four scatter sources in CT, i.e. external scattered radiations from the tube and table, internal scatter from the patient and backscatter from the shielding. For this purpose, CTDI phantoms filled with thermoluminescent dosimeters were scanned without apron, and then with an apron at 0, 2.5 and 5 cm from the primary field. Scatter from the tube was measured separately in air. The scatter contributions were separated and mathematically modelled. The protective efficiency of the apron was low, only 1.5% in scatter dose reduction on average. The apron at 0 cm from the beam lowered the dose by 7.5% at the phantom bottom but increased the dose by 2% at the top (backscatter) and did not affect the centre. When the apron was placed at 2.5 or 5 cm, the results were intermediate to the one obtained with the shielding at 0 cm and without shielding. The apron effectiveness is finally limited to the small fraction of external scattered radiation. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

A study of changes in the primary dose penetrating the protective apron on SID in x-ray radiography

International Nuclear Information System (INIS)

Choi, Seong Kwan

2016-01-01

This study is to figure out the amount of primary X-ray generated in SID 50cm, 1m, and 2m penetrating protective aprons in X-ray radiography for hands, skull, and lumbar spine. Results are as follows: Firstly, the exposure dose of primary X-ray which is low such as that of hand X-ray may be reduced by 270 times if protective aprons are worn, but it still slightly penetrates 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Secondly, the exposure dose of primary X-ray which is moderate such as that of skull X-ray may be reduced by 22 times if protective aprons are worn, but it still fairly penetrates 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Thirdly, the exposure dose of primary X-ray which is very high such as that of lumbar spine X-ray may be reduced b y 13 times if protective aprons a re worn, but it still penetrates a lot 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Therefore, people in X-ray room should not only wear protective aprons at any spaces that the primary X-ray can reach, but also need to stand behind the thick Pb shield to protect the body if it is inevitable to stay in the room

A study of changes in the primary dose penetrating the protective apron on SID in x-ray radiography

Energy Technology Data Exchange (ETDEWEB)

Choi, Seong Kwan [Dept. of Radiological Technology, Kwangju Health University, Gwangju (Korea, Republic of)

2016-12-15

This study is to figure out the amount of primary X-ray generated in SID 50cm, 1m, and 2m penetrating protective aprons in X-ray radiography for hands, skull, and lumbar spine. Results are as follows: Firstly, the exposure dose of primary X-ray which is low such as that of hand X-ray may be reduced by 270 times if protective aprons are worn, but it still slightly penetrates 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Secondly, the exposure dose of primary X-ray which is moderate such as that of skull X-ray may be reduced by 22 times if protective aprons are worn, but it still fairly penetrates 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Thirdly, the exposure dose of primary X-ray which is very high such as that of lumbar spine X-ray may be reduced b y 13 times if protective aprons a re worn, but it still penetrates a lot 0.3mm thick Pb protective aprons at SID 50cm, 1m, and 2m. Therefore, people in X-ray room should not only wear protective aprons at any spaces that the primary X-ray can reach, but also need to stand behind the thick Pb shield to protect the body if it is inevitable to stay in the room.

Improvement of the shield ability and lightweight of a radiation protective apron

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Keun; Jang, Young Il [Kwangju Health College, Kwang-ju (Korea, Republic of); Kim, Jung Min [Junior College of Health Sciences, Korea University, Seoul (Korea, Republic of)

2003-06-15

In this work, we characterized the shield ability and lightweight of radiation protective aprons which were consisted of various metal (Pb, Sn, Ni, Ti and Cu) by measuring the x-ray dose transmitted through the filters. The transmitted ratio and lead equivalent of various metal were obtained by linear interpolation and the lead equivalent of double layered filters contained Pb layer was determined. The transmitted ratio of the apron (0.25 mmPb) specified in KS B 0845 was 5.2%. The transmitted ratio of the filters at the thickness of 0.6 mm was decreased in the order of Ni (32.60%), Ti (17.75%), Cu (13.25%) and Sn (3.84%). From the results of experimental evaluation for combined filter of Pb and Sn, it was founded that in the case of the first Sn layer, the lead equivalent was higher than that of the first Pb layer. The lead equivalent corresponding to apron of 0.25 mmPb was obtained in the double layered filters of Sn (0.19 mm)-Pb (0.1 mm) and Pb (0.1 mm)-Sn (0.37 mm). Thus, the Sn-Pb filter had the lower weight about 13% than apron of 0.25 mmPb.

Improvement of the shield ability and lightweight of a radiation protective apron

International Nuclear Information System (INIS)

Kim, Young Keun; Jang, Young Il; Kim, Jung Min

2003-01-01

In this work, we characterized the shield ability and lightweight of radiation protective aprons which were consisted of various metal (Pb, Sn, Ni, Ti and Cu) by measuring the x-ray dose transmitted through the filters. The transmitted ratio and lead equivalent of various metal were obtained by linear interpolation and the lead equivalent of double layered filters contained Pb layer was determined. The transmitted ratio of the apron (0.25 mmPb) specified in KS B 0845 was 5.2%. The transmitted ratio of the filters at the thickness of 0.6 mm was decreased in the order of Ni (32.60%), Ti (17.75%), Cu (13.25%) and Sn (3.84%). From the results of experimental evaluation for combined filter of Pb and Sn, it was founded that in the case of the first Sn layer, the lead equivalent was higher than that of the first Pb layer. The lead equivalent corresponding to apron of 0.25 mmPb was obtained in the double layered filters of Sn (0.19 mm)-Pb (0.1 mm) and Pb (0.1 mm)-Sn (0.37 mm). Thus, the Sn-Pb filter had the lower weight about 13% than apron of 0.25 mmPb

Influence of lead apron shielding on absorbed doses from panoramic radiography.

Science.gov (United States)

Rottke, D; Grossekettler, L; Sawada, K; Poxleitner, P; Schulze, D

2013-01-01

This study investigated the absorbed doses in a full anthropomorphic body phantom from two different panoramic radiography devices, performing protocols with and without applying a lead apron. A RANDO(®) full body phantom (Alderson Research Laboratories Inc., Stamford, CT) was equipped with 110 thermoluminescent dosemeters at 55 different sites and set up in two different panoramic radiography devices [SCANORA(®) three-dimensional (3D) (SOREDEX, Tuusula, Finland) and ProMax(®) 3D (Planmeca, Helsinki, Finland)] and exposed. Two different protocols were performed in the two devices. The first protocol was performed without any lead shielding, whereas the phantom was equipped with a standard adult lead apron for the second protocol. A two-tailed paired samples t-test for the SCANORA 3D revealed that there is no difference between the protocol using lead apron shielding (m = 87.99, s = 102.98) and the protocol without shielding (m = 87.34, s = 107.49), t(54) = -0.313, p > 0.05. The same test for the ProMax 3D showed that there is also no difference between the protocol using shielding (m = 106.48, s = 117.38) and the protocol without shielding (m = 107.75, s = 114,36), t(54) = 0.938, p > 0.05. In conclusion, the results of this study showed no statistically significant differences between a panoramic radiography with or without the use of lead apron shielding.

Geomorphology and sediment transport on a submerged back-reef sand apron: One Tree Reef, Great Barrier Reef

Science.gov (United States)

Harris, Daniel L.; Vila-Concejo, Ana; Webster, Jody M.

2014-10-01

Back-reef sand aprons are conspicuous and dynamic sedimentary features in coral reef systems. The development of these features influences the evolution and defines the maturity of coral reefs. However, the hydrodynamic processes that drive changes on sand aprons are poorly understood with only a few studies directly assessing sediment entrainment and transport. Current and wave conditions on a back-reef sand apron were measured during this study and a digital elevation model was developed through topographic and bathymetric surveying of the sand apron, reef flats and lagoon. The current and wave processes that may entrain and transport sediment were assessed using second order small amplitude (Stokes) wave theory and Shields equations. The morphodynamic interactions between current flow and geomorphology were also examined. The results showed that sediment transport occurs under modal hydrodynamic conditions with waves the main force entraining sediment rather than average currents. A morphodynamic relationship between current flow and geomorphology was also observed with current flow primarily towards the lagoon in shallow areas of the sand apron and deeper channel-like areas directing current off the sand apron towards the lagoon or the reef crest. These results show that the short-term mutual interaction of hydrodynamics and geomorphology in coral reefs can result in morphodynamic equilibrium.

Protection by lead aprons against diffused radiation by medical x-ray utilization

International Nuclear Information System (INIS)

Huyskens, C.J.; Franken, Y.; Hummel, W.

1995-01-01

A lead apron can reduce the effective dose of radiological workers in medical roentgen applications. The reduction is not only determined by the thickness of the lead, but in particular by the model and fit of the apron. It also depends on the geometry of the radiation field to which the worker is exposed and the tube voltage. Based on model calculations it is determined how much protection against radiation is possible. 6 figs., 1 tab., 5 refs

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

International Nuclear Information System (INIS)

Cremen, S.A.; McNulty, J.P.

2014-01-01

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

A comparison of dose savings of lead and lightweight aprons for shielding of 99m-Technetium radiation

International Nuclear Information System (INIS)

Warren-Forward, H.; Cardew, P.; Smith, B.; Clack, L.; McWhirter, K.; Johnson, S.; Wessel, K.

2007-01-01

Nuclear medicine technologists (NMTs) have the highest effective doses of radiation among medical workers. With increase in the use of lightweight materials in diagnostic radiography, the aim was to compare the effectiveness of lead and lightweight aprons in shielding from 99m-Technetium ( 99m Tc) gamma rays. The doses received from a scattering phantom to the entrance, 9 cm depth and exit of a phantom were measured with LiF:Mg, Cu, P thermoluminescent dosemeters (TLDs). Doses and spectra were assessed without no shielding, with 0.5-mm lead and lightweight aprons. The lead and lightweight aprons decreased entrance surface doses by 76 and 59%, respectively. The spectral analysis showed that the lightweight apron provided better dose reduction at energies 99m Tc labelled radiopharmaceutical. (authors)

Efficiency of lead aprons in blocking radiation − how protective are they?

Directory of Open Access Journals (Sweden)

Seung-Jae Hyun

2016-05-01

Interpretation: The 0.5 mm lead aprons blocked just over one third of the radiation scattered towards the surgeon. Use of robotic-guidance in a minimally invasive approach provided for a reduction of 62.5% of the overall radiation the surgeon was exposed to during open conventional approach. We conclude that reduced radiation use (e.g. by using robotic guidance is a more effective strategy for minimizing exposure to radiation than reliance on protection by lead aprons, and recommend utilization of practices and technologies that reduce the surgical team’s routine exposure to X-rays.

Evaluasi Risiko Keterlambatan Pekerjaan Pembangunan Apron Baru Bandara Sultan Syarif Kasim II, Pekanbaru

OpenAIRE

Yulita, Syifa; Sandhyavitri, Ari; Malik, Alfian

2017-01-01

Implementation of the project of New Apron Development Workshop of Sultan Syarif Kasim II Airport, Pekanbaru from initial observations of previous authors poses a risk during the construction period of unpredictable events by civil engineer is a force majure condition such as unpredictable volume during interim planning The time set does not include unexpected or over volume work. The delay that occurred in the project of Advanced Construction Work of New Apron Sultan Syarif Kasim II Airport,...

Apron (no more dirty egg: (representations

Directory of Open Access Journals (Sweden)

Tânia Regina Oliveira Ramos

2013-09-01

Full Text Available The title, in its ambiguity, comes from a song in tribute to mothers, “Mommy, Mommy. I remember slipper in hand, all of the apron dirty egg,” The purpose of this essay is to show contemporary narratives that seek to represent by the writting the sense of passion of the modern urban woman, her experiences of morality, what is left of what was called archetypally respectability and domestic responsibility.

WFF - Darstellung Fahrzeuge im Apron-HMI

OpenAIRE

Loth, Steffen

2010-01-01

Während der Laufzeit des WFF-Projektes wurde das operationelle A-SMGCS am Flughafen Hamburg realisiert. Dazu gehört neben den verschiedenen Systemkomponenten auch das Verkehrslagedisplay, das für Tower und Apron verwendet wird. Das System wurde gegen Ende des WFF-Projektes fertig gestellt. Wesentliches Element für die Arbeit eines Lotsen mit Unterstützung eines A-SMGCS ist dabei das Verkehrslagedisplay, dem eine topografische Darstellung des Flughafens zu Grunde liegt. Dazu kommt die Darst...

APRON: A Cellular Processor Array Simulation and Hardware Design Tool

Science.gov (United States)

Barr, David R. W.; Dudek, Piotr

2009-12-01

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.

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.

Apron (no more) dirty egg: (re)presentations

OpenAIRE

Tânia Regina Oliveira Ramos

2013-01-01

The title, in its ambiguity, comes from a song in tribute to mothers, “Mommy, Mommy. I remember slipper in hand, all of the apron dirty egg,” The purpose of this essay is to show contemporary narratives that seek to represent by the writting the sense of passion of the modern urban woman, her experiences of morality, what is left of what was called archetypally respectability and domestic responsibility.

The Dermal Apron Technique for Immediate Implant Socket Management: A Novel Technique.

Science.gov (United States)

Levin, Barry P

2016-01-01

With immediate implant placement and provisionalization (IIP) in the esthetic zone, measures to counter hard and soft tissue loss are frequently necessary. To reduce the morbidity associated with bone and connective tissue procurement, various exogenous materials are utilized. The "Dermal Apron Technique" presented in this article demonstrates the use of a composite bone particulate (allograft/xenograft) plus a dermal allograft, adapted around screw-retained temporary crowns and secured within a subperiosteal pouch. The purpose is to augment the thickness of peri-implant mucosa for the purpose of preserving ridge dimensions and preventing mucosal recession. Controlled studies are required to further support its use. Clinical significance: Soft tissue health and harmony are critical for successful implant therapy in the esthetic regions of the dentition. Often, autogenous soft tissue grafts are used to augment peri-implant soft tissues. The Dermal Apron Technique is a method, that in specific situations, obviates the need for autogenous grafting. This reduces treatment time and morbidity associated with procurement of these grafts. The Dermal Apron Technique is used simultaneous with immediate placement and provisionalization and can improve long-term esthetic outcomes for patients. © 2016 Wiley Periodicals, Inc.

Comparison between the chest dose and the neck dose of workers with protective aprons at PNC plutonium fuel fabrication facilities

Energy Technology Data Exchange (ETDEWEB)

Tsujimura, Norio; Momose, Takumaro; Shinohara, Kunihiko [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works

1996-06-01

The dose equivalents recorded by a chest dosemeter under the protective apron and a neck dosemeter above the apron, worn by workers in the fabrication process of MOX fuels at PNC Tokai works, are compared. The ratio of the chest and neck dose equivalent is from 3 to 4. The effective dose equivalent calculated from a weighted combination of the dosemeter readings is about 2 times of the dose under protective aprons. (author)

Comparison between the chest dose and the neck dose of workers with protective aprons at PNC plutonium fuel fabrication facilities

International Nuclear Information System (INIS)

Tsujimura, Norio; Momose, Takumaro; Shinohara, Kunihiko

1996-01-01

The dose equivalents recorded by a chest dosemeter under the protective apron and a neck dosemeter above the apron, worn by workers in the fabrication process of MOX fuels at PNC Tokai works, are compared. The ratio of the chest and neck dose equivalent is from 3 to 4. The effective dose equivalent calculated from a weighted combination of the dosemeter readings is about 2 times of the dose under protective aprons. (author)

A study on the apron shielding ratio according to electromagnetic radiation energy

Energy Technology Data Exchange (ETDEWEB)

Jang, Dong Gun; Lee, Sang Ho; Choi, Hyung Seok; Son, Joo Chul; Yoon, Chang Yong; Ji, Yung Sik; Cho, Yong In; Lee, Hong Je; Yang, Seoung Oh [Dept. of Nuclear Medicine, Dongnam Institute of Radiological and Medical Sciences Cancer Center, Busan (Korea, Republic of)

2014-12-15

The medical institution has been used electromagnetic radiation of various energy. But researchers are divided on whether using apron for radiation shielding will be effective or not. The purpose of present study was to analyze electromagnetic radiation shielding effect of apron by using Monte Carlo simulation. 1 MBq electromagnetic radiation was emitted from 10-500 keV at 10 keV increments in Monte Carlo simulation. Then shielded radiation dose difference was confirmed, when 0.25 mmPb shield use for shielding. As a results, shielding ratio was markedly decreased in high energy electromagnetic radiation. The radiation dose was inversely increased with 0.25 mmPb shielding.

A study on the apron shielding ratio according to electromagnetic radiation energy

International Nuclear Information System (INIS)

Jang, Dong Gun; Lee, Sang Ho; Choi, Hyung Seok; Son, Joo Chul; Yoon, Chang Yong; Ji, Yung Sik; Cho, Yong In; Lee, Hong Je; Yang, Seoung Oh

2014-01-01

The medical institution has been used electromagnetic radiation of various energy. But researchers are divided on whether using apron for radiation shielding will be effective or not. The purpose of present study was to analyze electromagnetic radiation shielding effect of apron by using Monte Carlo simulation. 1 MBq electromagnetic radiation was emitted from 10-500 keV at 10 keV increments in Monte Carlo simulation. Then shielded radiation dose difference was confirmed, when 0.25 mmPb shield use for shielding. As a results, shielding ratio was markedly decreased in high energy electromagnetic radiation. The radiation dose was inversely increased with 0.25 mmPb shielding

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

Science.gov (United States)

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 offspring and many of their partners). The primary aims of the APrON study were to determine the relationships between maternal nutrient intake and status, before, during and after gestation, and (1) maternal mood; (2) birth and obstetric outcomes; and (3) infant neurodevelopment. We have collected comprehensive maternal nutrition, anthropometric, biological and mental health data at multiple points in the pregnancy and the post-partum period, as well as obstetrical, birth, health and neurodevelopmental outcomes of these pregnancies. The study continues to follow the infants through to 36 months of age. The current report describes the study design and methods, and findings of some pilot work. The APrON study is a significant resource with opportunities for collaboration. © 2012 John Wiley & Sons Ltd.

Efficacy of aprons equivalent to 0.5 mm of lead in PET procedures using the Monte Carlo method

International Nuclear Information System (INIS)

Fonseca, R.B.; Amaral, A.; Campos, L.

2012-01-01

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)

Evaluation of the transmitted exposure through lead equivalent aprons used in a radiology department, including the contribution from backscatter

International Nuclear Information System (INIS)

Christodoulou, Emmanuel G.; Goodsitt, Mitchell M.; Larson, Sandra C.; Darner, Katie L.; Satti, Jahangir; Chan, H.-P.

2003-01-01

A study was conducted to evaluate the radiation transmission through lead equivalent aprons that are used in a radiology department. A large area beam (poor geometry) was employed for the transmission measurements, and backscatter was simulated by placing 7 '' of Lucite behind each apron. Separate ionization chambers were used to measure the incident and transmitted x-ray beams. Transmission measurements were made at 70 kVp and 100 kVp through aprons and protective shields from eight different vendors that were marked 0.25 mm and 0.5 mm lead equivalent. Transmissions through 0.254 mm and 0.508 mm of pure lead were also measured and were compared with the transmissions through the lead equivalent materials. In addition, the area densities of the aprons were measured to compare radiation transmission with respect to the weights of the aprons. At 70 kVp, the transmission through 0.254 mm of pure lead was 5.4% and the transmissions through the 0.25 mm lead equivalent materials were 4.3% to 10.2% with a mean value of 7.1% and a standard deviation (s.d.) of 1.4%. At 100 kVp, the values were 15% for 0.254 mm pure lead and 12.3% to 20.7% (mean 16.8%, s.d. 2.1%) for the 0.25 mm lead equivalent materials. The transmission through the 0.508 mm pure lead sample was 0.9% at 70 kVp, and the corresponding transmissions through the 0.5 mm lead equivalent materials were 0.6% to 1.6% (mean 1.0%, s.d. 0.2%). At 100 kVp, the transmission through the 0.508 mm lead sample was 5% and those through the 0.5 mm lead equivalent materials were 3.5% to 6.7% (mean 4.9%, s.d. 0.7%). The radiation transmissions at 70 kVp, through two 'lead-free' 0.5 mm lead equivalent aprons, were 1.7% and 1.9% and at 100 kVp the transmissions were 6.1% and 6.8%, respectively. This study indicates that there is a need to establish methods for acceptance testing of aprons and a need to establish acceptance limits for the x-ray transmission of aprons at specific kVp values. There is also a need for the

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

International Nuclear Information System (INIS)

Senthilkumar, S.

2014-01-01

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

Modeling an Ice-rich Lobate Debris Apron in Deuteronilus Mensae

Science.gov (United States)

Fastook, J. L.; Head, J. W.; Madeleine, J.-B.; Forget, F.; Marchant, D.

2010-03-01

Models help interpret observed glacial deposits and test formation scenarios. We examine a lobate debris apron recently proven to contain pure water ice. Two hypotheses are tested: alcove-only and collapse from a larger ice sheet driven by a GCM.

Response of TLD badge for the estimation of exposure conditions in diagnostic x-ray departments - use of lead aprons

International Nuclear Information System (INIS)

Pradhan, A.S.; Chatterjee, S.; Bakshi, A.K.

2002-01-01

The present study was undertaken to ascertain the conditions of exposure of the TLD badge and to evaluate the inaccuracy involved in the estimation of dose received by the worker using an averaged lead apron transmission factor for the use of the badge above lead apron

Use of lead aprons - further considerations of estimation of doses and conditions of acute exposures of TLD badge in diagnostic x-ray institutions

International Nuclear Information System (INIS)

Pradhan, A.S.; Chatterjee, S.

2003-01-01

In the recent study the authors reported that the exposure conditions of the use of the TLD badge, whether worn under or over the lead apron could be estimated from the readout of the TLD badge used in X-ray diagnostic departments. The effectiveness of lead aprons procured from different suppliers having the same value of quoted nominal lead equivalence was found to vary severely and this indicated some limitation in the applicability of the method of evaluation of exposure conditions of the badge. The transmission factors for the lead aprons varied up to a factor of 15 for the same value of quoted nominal lead equivalence procured from three different suppliers. This is of serious consequences in radiation protection and attracts attention for quality control. An error in the estimation of the exposure conditions of the TLD badge could lead to an underestimation of doses up to 4 times using the prevalent method. The estimation of the actual doses of radiation workers in the cases of over-exposures for the situations of the use of the TLD badge over the lead apron showed that the variation in the quality of lead aprons could be wrong in the range from 1.6 to 25 times even if the kVp of the machine is exactly known. Therefore, attempt should not be made to estimate the actual doses under lead apron from the readout of the TLD badge worn over the apron, as the real values of the transmission factors of the aprons and kVp of the X-ray machine may not be available. (author)

Facies-controlled reservoir properties in ramp-fan and slope-apron deposits, Miocene Puente Formation, Los Angeles basin

Energy Technology Data Exchange (ETDEWEB)

Lyons, K.T.; Geving, R.L.; Suchecki, R.K.

1989-03-01

The Miocene Puente Formation in outcrops of the eastern Los Angeles basin is interpreted as a succession of slope-apron and ramp-fan deposits that accumulated in a prism-rise wedge. The principal depositional components of this dominantly base-of-slope and ramp system are ramp-fan channels and lobes, and slope-channel and slope-apron channel/interchannel deposits. Facies-specific textural, compositional, and diagenetic attributes observed in thin section assist in the classification of depositional facies. Specifically, occurrence of carbonate cement, clay mineralogy, and abundance of organic material vary as a function of component facies architecture of the depositional system. Slope and ramp-fan channel-fill sandstones are characterized by pervasive carbonate cements, including poikilotopic and fine-grained calcite, fine-grained and baroque dolomite, and minor siderite. Diagenetic clays predate carbonate cements, and dolomite predates coarser, void-filling calcite. Ramp-fan lobe and interchannel deposits are carbonate free but are rich in detrital clay and organic matter. Diagenetic clays include mixed-layer illite/smectite and kaolinite. Sediments deposited in slope-apron channel fill are virtually cement free except for small amounts of authigenic illite/smectite. Slope-apron interchannel deposits are characterized by high content of organic matter and clay-rich matrix. Potential reservoir characteristics, such as grain size, sorting, and abundance of depositional clay matrix, are related to the primary sedimentary properties of depositional architectural components in the ramp-fan and slope-apron system. Additional diagenetic modifications, without consideration of compaction, were controlled by precipitation reactions associated with fluid flow along pathways related to the depositional architectural framework.

Radiation exposure of radiologists during angiography: Dose measurements outside the lead apron

International Nuclear Information System (INIS)

Fischer, H.; Przetak, C.; Teubert, G.; Ewen, K.; Moedder, U.

1995-01-01

The aim of this study was to provide practical information to angiographers concerning radiation exposure to body parts not covered by lead aprons. Individual doses to the neck and hands of radiologists measured in micro-Sieverts were obtained during the course of 80 angiographies of various types. The number of diagnostic and interventional procedures, which might lead to exceeding permissible doses, have been calculated. Possibilities of estimating doses during angiography by means of parameters such as screening times were examined statistically. Especially with regard to the hands, estimations of the doses are insufficient (correlation r=0.21). Radiologists who undertake much angiographic and particularly interventional work may reach exposure levels requiring protective measures in addition to lead aprons. (orig.) [de

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.

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

International Nuclear Information System (INIS)

Wood, R.E.; Harris, A.M.; van der Merwe, E.J.; Nortje, C.J.

1991-01-01

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

Assessment of the effectiveness of attenuation of leaded aprons through TLD dosimetry and Monte Carlo simulation method

Energy Technology Data Exchange (ETDEWEB)

Olaya D, H.; Diaz M, J. A.; Martinez O, S. A. [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, 150003 Tunja, Boyaca (Colombia); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

2016-10-15

Were performed experimental setups using an X-ray equipment continuous emission Pantak DXT-3000 and three types of leaded aprons with thickness of 0.25, 0.5 and 0.75 mm coated with Mylar Fiber coated Mylar on its surface. Apron was located at a distance of 2.5 m with respect focus in order to cover a radiation field size of a meter in diameter. At the beam output were added aluminum filtration in order to reproduce qualities of narrow beams N-40 (E{sub efective} = 33 keV), N-80 (E{sub efective} = 65 keV) and N-100 (E{sub efective} = 83 keV) according to the ISO standard 4037 (1-3). Each lead apron were fixed 10 TLD dosimeters over its surface, 5 dosimeters before and 5 dosimeters after with respect to X-ray beam and were calibrated for Harshaw 4500 thermoluminescent reader system order to assess the attenuation of each apron. Were performed dosimeters readings and were calculated the attenuation coefficients for each effective energy of X-ray quality. In order to confirm the method of effective energy of ISO-4037 and evaluate effectiveness of lead aprons based on energy range for each medical practice was made a Monte Carlo simulation using code GEANT-4, calculating the fluence and absorbed dose in each one of the dosimeters Monte Carlo, then coefficients of linear attenuation were calculated and compared with the experimental data and reported by the National Institute of Standards and Technology (Nist). Finally, results are consistent between theoretical calculation and experimental measures. This work will serve to make assessments for other personalized leaded protections. (Author)

GATEWAY Report Brief: SSL Evaluation: Philadelphia International Airport Apron Lighting

Energy Technology Data Exchange (ETDEWEB)

None, None

2015-10-30

Summary of report that documents a trial installation of LED apron lighting that replaced the existing high-pressure sodium luminaires at Philadelphia International Airport. Such high-mast applications remain challenging for LED technology, and the lessons learned from this project may help facility managers and LED product manufacturers better meet those challenges.

the Modeling of Hydraulic Jump Generated Partially on Sloping Apron

Directory of Open Access Journals (Sweden)

Shaker Abdulatif Jalil

2017-12-01

Full Text Available Modeling aims to characterize system behavior and achieve simulation close as possible of the reality. The rapid energy exchange in supercritical flow to generate quiet or subcritical flow in hydraulic jump phenomenon is important in design of hydraulic structures. Experimental and numerical modeling is done on type B hydraulic jump which starts first on sloping bed and its end on horizontal bed.  Four different apron slopes are used, for each one of these slopes the jump is generated on different locations by controlling the tail water depth.  Modelling validation is based on 120 experimental runs which they show that there is reliability. The air volume fraction which creates in through hydraulic jump varied between 0.18 and 0.28. While the energy exchanges process take place within 6.6, 6.1, 5.8, 5.5 of the average relative jump height for apron slopes of 0.18, 0.14, 0.10, 0.07 respectively. Within the limitations of this study, mathematical prediction model for relative hydraulic jump height is suggested.The model having an acceptable coefficient of determination.

Assessment of the effectiveness of attenuation of leaded aprons through TLD dosimetry and Monte Carlo simulation method

International Nuclear Information System (INIS)

Olaya D, H.; Diaz M, J. A.; Martinez O, S. A.; Vega C, H. R.

2016-10-01

Were performed experimental setups using an X-ray equipment continuous emission Pantak DXT-3000 and three types of leaded aprons with thickness of 0.25, 0.5 and 0.75 mm coated with Mylar Fiber coated Mylar on its surface. Apron was located at a distance of 2.5 m with respect focus in order to cover a radiation field size of a meter in diameter. At the beam output were added aluminum filtration in order to reproduce qualities of narrow beams N-40 (E_e_f_e_c_t_i_v_e = 33 keV), N-80 (E_e_f_e_c_t_i_v_e = 65 keV) and N-100 (E_e_f_e_c_t_i_v_e = 83 keV) according to the ISO standard 4037 (1-3). Each lead apron were fixed 10 TLD dosimeters over its surface, 5 dosimeters before and 5 dosimeters after with respect to X-ray beam and were calibrated for Harshaw 4500 thermoluminescent reader system order to assess the attenuation of each apron. Were performed dosimeters readings and were calculated the attenuation coefficients for each effective energy of X-ray quality. In order to confirm the method of effective energy of ISO-4037 and evaluate effectiveness of lead aprons based on energy range for each medical practice was made a Monte Carlo simulation using code GEANT-4, calculating the fluence and absorbed dose in each one of the dosimeters Monte Carlo, then coefficients of linear attenuation were calculated and compared with the experimental data and reported by the National Institute of Standards and Technology (Nist). Finally, results are consistent between theoretical calculation and experimental measures. This work will serve to make assessments for other personalized leaded protections. (Author)

Effect of Submergence and Apron Length on Spillway Scour: Case Study

Directory of Open Access Journals (Sweden)

Seungho Hong

2015-10-01

Full Text Available Large-scale water resources systems are often managed by an integrated set of hydraulic structures that are vulnerable to wider ranges of discharge and tailwater elevation than envisioned in their original design due to climate change and additional project objectives such as fostering healthy ecosystems. The present physical model study explored the performance of a spillway structure on the Kissimmee River, operated by the South Florida Water Management District, under extreme conditions of drought and flooding with accompanying low and high tailwater levels for both gate-controlled and uncontrolled spillway flow conditions. Maximum scour depths and their locations for two different riprap apron lengths downstream of the spillway stilling basin were measured along with the complex flow fields prior to scour. Effects of tailwater submergence, type of spillway flow and riprap apron length on scour results are interpreted in terms of the measured turbulent kinetic energy and velocity distributions near the bed.

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.

Comparative effects of Apron plus 50DS and soil amendment on the ...

African Journals Online (AJOL)

recommended dose of Apron plus 50DS had lower percentage germination when compared to the other treatments while the untreated seeds (control) had the highest percentage germination. Seeds treated with ... However, there is no significant difference among the treatments in percentage ash and moisture content.

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.

Skin entrance dose with and without lead apron in digital panoramic radiography for selected sensitive body regions.

Science.gov (United States)

Schulze, Ralf Kurt Willy; Cremers, Catrin; Karle, Heiko; de Las Heras Gala, Hugo

2017-05-01

The aim of this study was to compare the dose at skin level at five significant anatomical regions for panoramic radiography devices with and without lead apron by means of a highly sensitive dosimeter. A female RANDO-phantom was exposed in five different digital panoramic radiography systems, and the dose at skin level was assessed tenfold for each measurement region by means of a highly sensitive solid-state-dosimeter. The five measurement regions selected were the thyroid, both female breasts, the gonads, and a central region in the back of the phantom. For each panoramic machine, the measurements were performed in two modes: with and without a commercial lead apron specifically designed for panoramic radiography. Reproducibility of the measurements was expressed by absolute differences and the coefficient of variation. Values between shielded and unshielded doses were pooled for each region and compared by means of the paired Wilcoxon tests (p ≤ 0.05). Reproducibility as represented by the mean CV was 22 ± 52 % (median 2.3 %) with larger variations for small dose values. Doses at skin level ranged between 0.00 μGy at the gonads and 85.39 μGy at the unshielded thyroid (mean ± SD 15 ± 24 μGy). Except for the gonads, the dose in all the other regions was significantly lower (p < 0.001) when a lead apron was applied. Unshielded doses were between 1.02-fold (thyroid) and 112-fold (at the right breast) higher than those with lead apron shielding (mean: 14-fold ± 18-fold). Although the doses were entirely very low, we observed a significant increase in dose in the radiation-sensitive female breast region when no lead apron was used. Future discussions on shielding requirements for panoramic radiography should focus on these differences in the light of the linear non-threshold (LNT) theory which is generally adopted in medical imaging.

The Erebus Montes Debris-Apron Population: Investigation of Amazonian Landscape Evolution

Science.gov (United States)

van Gasselt, S.; Orgel, C.; Schulz, J.

2014-04-01

Lobate debris aprons are considered to be indicators for the presence of ice and water reservoirs on Mars and are therefore sensitive to climate variability. The northern hemisphere of Mars is characterized by three major populations of debris aprons (see, e.g. [12]): (1) the Tempe Terra/Mareotis Fossae region [2, 5], (2) the Deuteronilus/Protonilus Mensae [1, 4, 8], and (3) the Phlegra Montes (PM) [3]. The broader PM area can subdivided inro a number of smaller populations dispersed across parts of Arcadia Planitia (see figure 1) of which the Erebus Montes located at 180-195oE, 25-41oN form a well-confined set of features. We here focus on age and erosional characteristics of the northern Erebus Montes (see inset in figure 1). Our study makes use of panchromatic image data obtained by the High Resolution Stereo Camera (HRSC) [9, 6] onboard Mars Express and the Context Camera (CTX) [7] onboard Mars Reconnaissance Orbiter. Image data analyses are supported by digital terrain-model data derived from HRSC based stereo imaging [10] and from Mars Orbiter Laser Altimeter (MOLA) [11]. We performed detailed geologic mapping at a scale of 1:10,000 and analysed age relationships and erosion rates based on a similar approach as outlined in [5] for the northern part of the Erebus Montes. The aim of this study is to compare feature characteristics to other populations in order to assess timing and the overarching control of landforms evolution in the Martian northern hemisphere. The EM compare geologically relatively well with the Phlegra Montes in terms of individual feature morphologies. The concentration based on cluster analysis (figure 1) shows an up to 10 times higher concentration of remnants per 25 km2 area peaking at 3.4×10-3 features for Erebus Montes. Debris aprons show well-defined age signals ranging from 15 Myr up to 145 Myr. Some units even show continuous degradation implying active denudation of the Noachian to Hesperian-aged remnant massifs. Based on the

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.

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

The Alberta Pregnancy Outcomes and Nutrition (APrON) cohort study : Rationale and methods

NARCIS (Netherlands)

Kaplan, B.J.; Giesbrecht, G.F.; Leung, B.M.; Field, C.J.; Dewey, D.; Bell, R.C.; Manca, D.P.; O'Beirne, M.; Johnston, D.W.; Pop, V.J.M.; Singhal, N.; Gagnon, L.; Bernier, F.P.; Eliasziw, M.; McCargar, L.J.; Kooistra, L.; Farmer, A.; Cantell, M.; Goonewardene, L.; Casey, L.M.; Letourneau, N.; Martin, J.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

Age and Stratigraphic Relationships in Massif-Debris-Apron Terrain in Western Phlegra Montes, Mars

Science.gov (United States)

Kress, A.; Head, J. W.; Safaeinili, A.; Holt, J.; Plaut, J.; Posiolova, L.; Phillips, R.; Seu, R.; Sharad Team

2010-03-01

SHARAD returns from lobate debris aprons (LDA) near Phlegra Montes may show similarly high ice contents to other LDA on Mars; geomorphology and surface ages of the deposits confirm this detection and support a debris-covered-glacier origin for LDA.

Radiation protection of staff in 111In radionuclide therapy--is the lead apron shielding effective?

Science.gov (United States)

Lyra, M; Charalambatou, P; Sotiropoulos, M; Diamantopoulos, S

2011-09-01

(111)In (Eγ = 171-245 keV, t1/2 = 2.83 d) is used for targeted therapies of endocrine tumours. An average activity of 6.3 GBq is injected into the liver by catheterisation of the hepatic artery. This procedure is time-consuming (4-5 min) and as a result, both the physicians and the technical staff involved are subjected to radiation exposure. In this research, the efficiency of the use of lead apron has been studied as far as the radiation protection of the working staff is concerned. A solution of (111)In in a cylindrical scattering phantom was used as a source. Close to the scattering phantom, an anthropomorphic male Alderson RANDO phantom was positioned. Thermoluminescent dosemeters were located in triplets on the front surface, in the exit and in various depths in the 26th slice of the RANDO phantom. The experiment was repeated by covering the RANDO phantom by a lead apron 0.25 mm Pb equivalent. The unshielded dose rates and the shielded photon dose rates were measured. Calculations of dose rates by Monte Carlo N-particle transport code were compared with this study's measurements. A significant reduction of 65 % on surface dose was observed when using lead apron. A decrease of 30 % in the mean absorbed dose among the different depths of the 26th slice of the RANDO phantom has also been noticed. An accurate correlation of the experimental results with Monte Carlo simulation has been achieved.

Radiation protection of staff in 111In radionuclide therapy-Is the lead apron shielding effective?

International Nuclear Information System (INIS)

Lyra, M.; Charalambatou, P.; Sotiropoulos, M.; Diamantopoulos, S.

2011-01-01

111 In (Eγ=171-245 keV, t1/2=2.83 d) is used for targeted therapies of endocrine tumours. An average activity of 6.3 GBq is injected into the liver by catheterisation of the hepatic artery. This procedure is time-consuming (4-5 min) and as a result, both the physicians and the technical staff involved are subjected to radiation exposure. In this research, the efficiency of the use of lead apron has been studied as far as the radiation protection of the working staff is concerned. A solution of 111 In in a cylindrical scattering phantom was used as a source. Close to the scattering phantom, an anthropomorphic male Alderson RANDO phantom was positioned. Thermoluminescent dosemeters were located in triplets on the front surface, in the exit and in various depths in the 26. slice of the RANDO phantom. The experiment was repeated by covering the RANDO phantom by a lead apron 0.25 mm Pb equivalent. The unshielded dose rates and the shielded photon dose rates were measured. Calculations of dose rates by Monte Carlo N-particle transport code were compared with this study's measurements. A significant reduction of 65 % on surface dose was observed when using lead apron. A decrease of 30 % in the mean absorbed dose among the different depths of the 26. slice of the RANDO phantom has also been noticed. An accurate correlation of the experimental results with Monte Carlo simulation has been achieved. (authors)

Origin of Sinuous Channels on the SW Apron of Ascraeus Mons and the Surrounding Plains, Mars

Science.gov (United States)

Schierl, Z. P.; Spencer, P.; Signorella, J.; Collins, A.; Schwans, B.; de Wet, A. P.; Bleacher, J. E.

2012-03-01

We used a variety of spacecraft imagery to determine the most likely origin for a network of sinuous channels found on the southwest apron of Ascraeus Mons and that extend out onto the surrounding plains.

Final Environmental Assessment for the Runway Extension and New Parking Apron at Tyndall Air Force Base, Florida

National Research Council Canada - National Science Library

2004-01-01

The Air Force prepared an Environmental Assessment (EA) of the potential environmental consequences of constructing a new heavy parking apron and runway extension at Tyndall Air Force Base (AFB), Florida...

Gonad protective effect of radiation protective apron in chest radiography

International Nuclear Information System (INIS)

Hashimoto, Masatoshi; Kato, Hideyuki; Fujibuchi, Toshiou; Ochi, Shigehiro; Morita, Fuminori

2004-01-01

Depending on the facility, a radiation protective apron (protector) is used to protect the gonad from radiation exposure in chest radiography. To determine the necessity of using a protector during chest radiography, we measured the effect of the protector on the gonad in this study. First, using a human body phantom, we measured the absorbed dose of the female gonad with and without the protector, using a thermoluminescence dosimeter (TLD), and confirmed its protective effect. Using the protector, the absorbed dose was reduced to 28±2% and 39±4% for field sizes of 14 x 17 inch and 14 x 14 inch, respectively. Next, we used Monte Carlo simulation and confirmed, not only the validity of the actual measurement values, but also the fact that the influence of radiation on the absorbed dose of the gonad was mostly from scattered radiation from inside the body for the 14 x 17 inch field size, and also from the X-ray tube for the 14 x 14 inch field size. Although a certain protective effect is achieved by using the protector, the radiation dose to the gonad is only a few μGy even without a protector. Thus, the risk of a genetic effect would be as small as 10 -8 . Given that acceptable risk is below 10 -6 , we conclude the use of a radiation protective apron is not necessary for diagnostic chest radiography. (author)

[Gonad protective effect of radiation protective apron in chest radiography].

Science.gov (United States)

Hashimoto, Masatoshi; Kato, Hideyuki; Fujibuchi, Toshiou; Ochi, Shigehiro; Morita, Fuminori

2004-12-01

Depending on the facility, a radiation protective apron (protector) is used to protect the gonad from radiation exposure in chest radiography. To determine the necessity of using a protector during chest radiography, we measured the effect of the protector on the gonad in this study. First, using a human body phantom, we measured the absorbed dose of the female gonad with and without the protector, using a thermoluminescence dosimeter (TLD), and confirmed its protective effect. Using the protector, the absorbed dose was reduced to 28+/-2% and 39+/-4% for field sizes of 14 x 17 inch and 14 x 14 inch, respectively. Next, we used Monte Carlo simulation and confirmed, not only the validity of the actual measurement values, but also the fact that the influence of radiation on the absorbed dose of the gonad was mostly from scattered radiation from inside the body for the 14 x 17 inch field size, and also from the X-ray tube for the 14 x 14 inch field size. Although a certain protective effect is achieved by using the protector, the radiation dose to the gonad is only a few microGy even without a protector. Thus, the risk of a genetic effect would be as small as 10(-8). Given that acceptable risk is below 10(-6), we conclude the use of a radiation protective apron is not necessary for diagnostic chest radiography.

GATEWAY Demonstrations: Philadelphia International Airport Apron Lighting: LED System Performance in a Trial Installation

Energy Technology Data Exchange (ETDEWEB)

Davis, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wilkerson, Andrea M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-10-30

This report documents a trial installation of LED apron lighting that replaced the existing high-pressure sodium luminaires at Philadelphia International Airport. Such high-mast applications remain challenging for LED technology, and the lessons learned from this project may help facility managers and LED product manufacturers better meet those challenges.

Evaluasi Kekuatan Perkerasan Sisi Udara (Runway,Taxiway,Apron Bandara Juanda Dengan Metode Perbandingan ACN-PCN

Directory of Open Access Journals (Sweden)

R. Haryo Triharso Seno

2015-03-01

Full Text Available Fasilitas sisi udara merupakan fasilitas pergerakan pesawat. Fasilitas ini harus memenuhi kekuatan struktur untuk melayani pergerakan pesawat-pesawat yang beroperasi sesuai dengan perencanaan. Tujuan dari penyusunan makalah ini adalah untuk menganalisis apakah perkerasan fasilitas sisi udara di Bandar Udara Juanda saat ini sudah memenuhi batas PCN yang dipersyaratkan atau belum. Analisis dilakukan dengan cara mengevaluasi kekuatan perkerasan runway, taxiway, dan apron eksisting menggunakan metode perbandingan PCN–ACN yang didapat dari pabrik pembuat pesawat, perhitungan dengan software COMFAA dan perhitungan dari Canadian Department of Transportation. Data yang digunakan adalah data pergerakan pesawat termasuk jumlah pergerakan tahunan dan tipe pesawat. Data kekuatan perkerasan sisi udara diperlukan untuk proses analisis. Hasil dari evaluasi menunjukkan B773 memiliki nilai ACN yang melebihi nilai PCN sebesar 50% untuk apron dan 25% untuk runway/taxiway. Besar kelebihan nilai ACN ini tidak mempengaruhi kekuatan struktural karena frekuensi pergerakan yang hanya 45 pergerakan per tahun. Dampak lain adalah pada fungsional perkerasan yang menunjukkan berkurangnya kekesatan runway dari hasil sand patch test.

Evaluation of the effectiveness of the lead aprons and thyroid shields worn by cardiologists in angiography departments of two main general hospitals in Mashhad, Iran

International Nuclear Information System (INIS)

Bahreyni Toossi, M.T.; Zare, H.; Bayani, Sh.; Esmaili, S.

2008-01-01

In recent years coronary artery angiography and angioplasty procedures have become very popular. Consequently radiation protection of the cardiologists, their assistants and technicians working in the vicinity of the x-ray tube is essential. Although in recent years in developed countries, high dose x-ray examinations such as coronary angiography have attracted the attention of health physicists but in developing countries it may take some years before it would receive any attention. In Iran generally film badge is the most common personal radiation monitoring device used for this purpose; it is placed beneath the lead apron. The shielding effect of different lead aprons and thyroid shields have been evaluated. TL dosimeters, suitably calibrated, were placed over and under lead shields corresponding to the thyroid and gonad positions of the personnel. 223 angiography examinations by femoral route were included in this work. Four types of aprons and three types of thyroid shields were examined. They were different in shape and lead equivalent thickness. Our results have revealed that apron with 0.35 mmPb, one piece and front closed has maximum shielding effect. Also thyroid shield with 0.5 mmPb and very large edge provide a better protection against radiation than other types. (author)

Organ-specific external dose coefficients and protective apron transmission factors for historical dose reconstruction for medical personnel.

Science.gov (United States)

Simon, Steven L

2011-07-01

ICRP/ICRU mono-energetic DCCs and the functions integrated over the air-kerma weighted photon fluence of the 12 defined x-ray spectra. The air kerma-weighted DCCs in this work were developed specifically for an irradiation geometry of anterior to posterior (AP) and for the following tissues: thyroid, breast, ovary, lens of eye, lung, colon, testes, heart, skin (anterior side only), red bone marrow (RBM), and brain. In addition, a series of functional relationships to predict DT Ka-1 values for RBM dependent on body mass index [BMI (kg m-2) ≡ weight per height] and average photon energy were derived from a published analysis. Factors to account for attenuation of radiation by protective lead aprons were also developed. Because lead protective aprons often worn by radiology personnel not only reduce the intensity of x-ray exposure but also appreciably harden the transmitted fluence of bremsstrahlung x-rays, DCCs were separately calculated for organs possibly protected by lead aprons by considering three cases: no apron, 0.25 mm Pb apron, and 0.5 mm Pb apron. For estimation of organ doses from conducting procedures with radioisotopes, continuous functions of the reported mono-energetic values were developed, and DCCs were derived by estimation of the function at relevant energies. By considering the temporal changes in primary exposure-related parameters (e.g., energy distribution), the derived DCCs and transmission factors presented here allow for more realistic historical dose reconstructions for medical personnel when monitoring badge readings are the primary data on which estimation of an individual's organ doses are based.

Experimental and numerical studies on aerodynamical noise in a high-speed elevator. ; Effect of apron on flow around elevator car. Kosoku elevator no kuriki soon ni kansuru kenkyu. ; Kagomawari no nagare ni oyobosu apron bu no eikyo

Energy Technology Data Exchange (ETDEWEB)

Matsuda, H.; Fukuyama, Y.; Miyasako, K.; Endo, M. (Toshiba Corp., Tokyo (Japan)); Yokono, Y. (Tokyo Institute of Technology, Tokyo (Japan). Research Laboratory of Precision Machinery and Electronics)

1993-08-25

For the purpose of reducing aerodynamic noise of a high-speed elevator, the flow around the elevator car was subjected to a flow visualization experiment and numerical simulation using a model simulating an elevator. The state of the flow in front of the door was observed by visualizing the field of flow around the model submerged in a water bath using a poster color tracer. Further, a wind tunnel experiment was carried out to observe the effects of flow at the side wall of the car. An oily agent using TiO2 as pigment was used for observing the pattern of oil film on the surface of the model and the observed results were recorded on a video tape. Since the oil solution is white, the place where the oil film is peeled by a strong shearing force exhibits a pattern of black color which is the color of the model substrate. Flow in front of the door is different depending on whether the car is in the upward motion or in the downward motion and affected by the presence of apron. During the downward motion of the car, the vertical vortices accompanying the flow detouring from the rear surface to the front surface of the apron are generated at both ends of the apron and thereby the streamlines are concentrated to generate accelerated flow in front of the door. Suppression of vertical voltices is important for reducing noise during downward motion. Peeled flow and vortex interference appear at the side and back of the car and forms a field of complex flow. 12 refs., 10 figs.

Numerical simulation of scour by a wall jet downstream of a solid apron

Energy Technology Data Exchange (ETDEWEB)

Barron, R.M. [Univ. of Windsor, Fluid Dynamics Research Inst., Windsor, Ontario (Canada)]. E-mail: az3@uwindsor.ca; Neyshabouri, S.A.A.S. [Univ. of Tarbiat Modarres, Dept. of Civil Engineering, Tehran (Iran, Islamic Republic of)]. E-mail: salehi@modares.ac.ir

2003-07-01

The time consuming and expensive nature of experimental research on scouring processes caused by flowing water makes it attractive to develop numerical tools for the prediction of the interaction of the fluid flow and the movable bed. In this paper the numerical simulation of scour caused by a wall jet flowing over a solid apron is presented. The flow is assumed to be two-dimensional, and the alluvium is cohesionless. The solution process, repeated at each time step, involves simulation of a turbulent wall jet flow, determination of the convection-diffusion of sand concentration, and prediction of the bed deformation. For simulation of the jet flow, the governing equations for momentum, mass balance and turbulent parameters are solved by the finite volume method. The SIMPLE scheme with momentum interpolation is used for pressure correction. A convection-diffusion equation is solved for sediment concentration. A boundary condition for concentration at the bed, which takes into account the effect of bed-load, is implemented. The time rate of deposition and scour at the bed is obtained by solving the continuity equation for sediment. A meshing technique is devised to deal with the movement of the bed adjacent to the rigid apron. Comparison of the simulation results with available experimental data shows favorable agreement for the time evolution of the scour hole and for the maximum scour depth. (author)

Volcanic or Fluvial Channels on Ascraeus Mons: Focus on the Source Area of Sinuous Channels on the Southeast Rift Apron

Science.gov (United States)

Signorella, J. D.; de Wet, A. P.; Bleacher, J. E.; Collins, A.; Schierl, Z. P.; Schwans, B.

2012-03-01

This study focuses on the source area of sinuous channels on the southeast rift apron on Ascraeus Mons, Mars and attempts to understand whether the channels were formed through volcanic or fluvial processes.

Analisis Perbandingan Material Slab Beton Pada Perkerasan Apron Dengan Menggunakan Program Bantu Elemen Hingga

Directory of Open Access Journals (Sweden)

Hendrawan Setyo Warsito

2016-04-01

Full Text Available Kekuatan slab beton sangat dipengaruhi oleh jenis material yang dipakai. Jenis material yang dimaksud adalah material beton dengan menggunakan PC (Portland Cement dan penggunaan geopolimer dalam komposisi campuran slab beton. Beton geopolimer merupakan beton yang ramah lingkungan. Permasalahan lain yang timbul adalah letak roda pesawat tidak selalu berada pada titik yang sama disuatu permukaan slab beton apron. Pada tugas akhir ini dimaksudkan untuk menganalisis suatu slab beton yang dibebani roda pesawat dengan campuran variasi material beton dan variasi letak roda pesawat pada slab beton dengan program bantu metode elemen hingga. Dengan data pergerakan pesawat, spesifikasi apron bandara Juanda kondisi eksisting. Dilakukan perhitungan tebal slab beton menggunakan software FAARFIELD dan diperoleh tebal slab beton sebesar 442,5 mm. Dari analisis program bantu elemen hingga dapat diperoleh tegangan pada slab beton yang ditimbulkan oleh pembebanan roda pesawat. Hasil validasi dari analisis tegangan menggunakan program bantu elemen hingga dengan analisis Westergaard yaitu memiliki nilai tegangan yang hampir sama pada ketebalan slab beton 450mm. Nilai tegangan tiap-tiap material beton menunjukan nilai tebal slab beton yang diijinkan untuk tipe pesawat tertentu. Dari analisis menggunakan program bantu elemen hingga tebal slab beton yang diijinkan untuk material slab beton PC yaitu sebesar 425mm. Sedangkan untuk material beton geopolimer yaitu sebesar  415 mm.

Internal Structure of a Lobate Debris Apron Complex in Eastern Hellas: Evidence for Multiple Mid-Latitude Glaciations on Mars

Science.gov (United States)

Quartini, E.; Holt, J. W.; Brothers, T. C.

2011-03-01

The past depositional history of a lobate debris apron complex in eastern Hellas has been investigated by conducting a combined analysis of its surface morphology and subsurface structure using a CTX mosaic and orbital radar sounding data from SHARAD.

Influence of a Commercial Lead Apron on Patient Skin Dose Delivered During Oral and Maxillofacial Examinations under Cone Beam Computed Tomography (CBCT).

Science.gov (United States)

Schulze, Ralf Kurt Willy; Sazgar, Mahssa; Karle, Heiko; de Las Heras Gala, Hugo

2017-08-01

The purpose of this paper is to investigate the impact of a commercial lead apron on patient skin dose delivered during maxillofacial CBCT in five critical regions by means of solid-state-dosimetry. Five anatomical regions (thyroid gland, left and right breast, gonads, back of the phantom torso) in an adult female anthropomorphic phantom were selected for dose measurement by means of the highly sensitive solid-state dosimeter QUART didoSVM. Ten repeated single exposures were assessed for each patient body region for a total of five commercial CBCT devices with and without a lead apron present. Shielded and non-shielded exposures were compared under the paired Wilcoxon test, with absolute and relative differences computed. Reproducibility was expressed as the coefficient of variation (CV) between the 10 repeated assessments. The highest doses observed at skin level were found at the thyroid (mean shielded ± SD: 450.5 ± 346.7 μGy; non-shielded: 339.2 ± 348.8 μGy, p = 0.4922). Shielding resulted in a highly significant (p < 0.001) 93% dose reduction in skin dose in the female breast region with a mean non-shielded dose of approximately 35 μGy. Dose reduction was also significantly lower for the back-region (mean: -65%, p < 0.0001) as well as for the gonad-region (mean: -98%, p < 0.0001) in the shielded situation. Reproducibility was inversely correlated to skin dose (Rspearman = -0.748, p < 0.0001) with a mean CV of 10.45% (SD: 24.53 %). Skin dose in the thyroid region of the simulated patient was relatively high and not influenced by the lead apron, which did not shield this region. Dose reduction by means of a commercial lead apron was significant in all other regions, particularly in the region of the female breast.

Hypsometric Analysis of Glacial Features: A Survey of Lobate Debris Apron Populations in Eastern Hellas Basin and Deuteronilus Mensae, Mars

Science.gov (United States)

Rutledge, A. M.; Christensen, P. R.

2014-07-01

Hypsometric curves of lobate debris apron populations in Hellas Basin and Deuteronilus Mensae were evaluated and compared with respect to inferred ice accumulation and flow. Curve types are elevation-dependent, indicating a past shift in climate.

[The apron mucosal flap of the lower lip for the repair of the secondary deformities of the cleft lip].

Science.gov (United States)

Wu, K; Xu, J; Lin, Y

1996-05-01

Twelve cases of secondary deformities of the cleft lip were repaired with the apron mucosal flap of the lower lip. The operation method is described. The advantages and disadvantages are discussed. Good results were obtained in patients with mild or medium secondary deformities.

Constraining the Timing of Lobate Debris Apron Emplacement at Martian Mid-Latitudes Using a Numerical Model of Ice Flow

Science.gov (United States)

Parsons, R. A.; Nimmo, F.

2010-03-01

SHARAD observations constrain the thickness and dust content of lobate debris aprons (LDAs). Simulations of dust-free ice-sheet flow over a flat surface at 205 K for 10-100 m.y. give LDA lengths and thicknesses that are consistent with observations.

Comparison of a suspended radiation protection system versus standard lead apron for radiation exposure of a simulated interventionalist.

Science.gov (United States)

Marichal, Daniel A; Anwar, Temoor; Kirsch, David; Clements, Jessica; Carlson, Luke; Savage, Clare; Rees, Chet R

2011-04-01

To evaluate the radiation protective characteristics of a system designed to enhance operator protection while eliminating weight to the body and allowing freedom of motion. Radiation doses to a mock interventionalist were measured with calibrated dosimeters in a clinical interventional suite. A standard lead apron (SLA; Pb equivalent, 0.5 mm) was compared with a suspended radiation protection system (ZeroGravity; Zgrav) that shields from the top of the head to the calves (except the right arm and left forearm) with a complex overhead motion system that eliminates weight on the operator and allows freedom of motion. Zgrav included a suspended lead apron with increased lead equivalency, greater length, proximal left arm and shoulder coverage, and a wraparound face shield of 0.5 mm Pb equivalency. A 26-cm-thick Lucite stack (ie, mock patient) created scatter during 10 controlled angiography sequences of 120 exposures each. Parameters included a field of view of 40 cm, table height of 94 cm, 124 cm from the tube to image intensifier, 50 cm from the image center to operator, 66 kVp, and 466-470 mA. Under identical conditions, average doses (SLA vs Zgrav) were 264 versus 3.4 (ratio, 78) to left axilla (P < .001), 456 versus 10.2 (ratio, 45) to left eye (P < .001), 379.4 versus 6.6 (ratio, 57) to right eye (P < .005), and 18.8 versus 1.2 (ratio, 16) to gonad (P < .001). Relative to a conventional lead apron, the Zgrav system provided a 16-78-fold decrease in radiation exposure for a mock interventionalist in a simulated clinical setting. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

Preliminary results of an attempt to predict over apron occupational exposure of cardiologists from cardiac fluoroscopy procedures based on DAP (dose area product) values.

Science.gov (United States)

Toossi, Mohammad Taghi Bahreyni; Mehrpouyan, Mohammad; Nademi, Hossein; Fardid, Reza

2015-03-01

This study is an effort to propose a mathematical relation between the occupational exposure measured by a dosimeter worn on a lead apron in the chest region of a cardiologist and the dose area product (DAP) recorded by a meter attached to the X-ray tube. We aimed to determine factors by which DAP values attributed to patient exposure could be converted to the over-apron entrance surface air kerma incurred by cardiologists during an angiographic procedure. A Rando phantom representing a patient was exposed by an X-ray tube from 77 pre-defined directions. DAP value for each exposure angle was recorded. Cardiologist exposure was measured by a Radcal ionization chamber 10X5-180 positioned on a second phantom representing the physician. The exposure conversion factor was determined as the quotient of over apron exposure by DAP value. To verify the validity of this method, the over-apron exposure of a cardiologist was measured using the ionization chamber while performing coronary angiography procedures on 45 patients weighing on average 75 ± 5 kg. DAP values for the corresponding procedures were also obtained. Conversion factors obtained from phantom exposure were applied to the patient DAP values to calculate physician exposure. Mathematical analysis of our results leads us to conclude that a linear relationship exists between two sets of data: (a) cardiologist exposure measured directly by Radcal & DAP values recorded by the X-ray machine system (R (2) = 0.88), (b) specialist measured and estimated exposure derived from DAP values (R (2) = 0.91). The results demonstrate that cardiologist occupational exposure can be derived from patient data accurately.

Study on abrasion resisting material for apron of dam; Dam apron bu no taimamo sozai ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Inaba, H.; Hiraki, M.; Miyamoto, T. [Hokuriku Electric Power Co. Inc., Toyama (Japan)

1995-01-25

A `laminated rubber tile` and a `shock absorbing holed-in anchor` were devised in connection with the apron of a dam for a hydroelectric power plant. As the result of a survey on the hydroelectric power plants, ten plus places were observed where a general kind of concrete was severely worn in the company territory; but, there were substantial number of rubber materials that had still been sound for over ten years after the installation. In spite of the soundness of the rubber tiles, however, it was observed that their anchor supports had been cut and separated. An abrasion comparison test of concrete and rubber materials revealed that the rubber materials were considerably superior in abrasion resistance. Various rubber tiles were tested for abrasion resistance, tear strength, tensile strength, impact strength, etc.; and methods for fixing rubber tiles were also tested such as a holed-in anchor, chemical anchor and adhesives. As a result, a laminated rubber tile was designed with its upper layer constituted of a rubber sold on the market and its lower layer of a fiber reinforced rubber also on the market, and so was a shock absorbing type holed-in anchor. 1 ref., 11 figs., 4 tabs.

Thermal analysis of fractures at Cerberus Fossae, Mars: Detection of air convection in the porous debris apron

Science.gov (United States)

Antoine, R.; Lopez, T.; Baratoux, D.; Rabinowicz, M.; Kurita, K.

2011-08-01

This study investigates the cause of high nighttime temperatures within Cerberus Fossae, a system of fractures affecting the Central Elysium Planitia. The inner parts (walls and floor) of the fractures are up to 40 K warmer than the surrounding plains. However, several temperature profiles exhibit a local temperature minima occurring in the central part of the fractures. We examined first the influence of cooling efficiency at night in the case of a strong reduction of the sky proportion induced by the fracture's geometry. However, the lack of correlation between temperature and sky proportion, calculated from extracted Mars Orbiter Laser Altimeter (MOLA) profiles argues against this hypothesis. Albedo variations were considered but appear to be limited within the fractures, and are generally not correlated with the temperatures. Variations of the thermal properties of bedrocks exposures, debris aprons and sand dunes inferred from high-resolution images do not either correlate with temperature variations within the fractures. As none of these factors taken alone, or combined, can satisfactorily explain the temperature variations within and near the fracture, we suggest that geothermal heat transported by air convection within the porous debris aprons may contribute to explain high temperatures at night and the local minima on the fracture floor. The conditions for the occurrence of the suggested phenomenon and the consequences on the surface temperature are numerically explored. A conservative geothermal gradient of 20 mW/m 2 was used in the simulations, this value being consistent with either inferred lithosphere elastic thicknesses below the shield volcanoes of the Tharsis dome or values predicted from numerical simulations of the thermal evolution of Mars. The model results indicate that temperature differences of 10-20 K between the central and upper parts of the fracture are explained in the case of high Darcy velocities which require high permeability values

Apron heights around stepped massifs in the Cydonia Mensae region: Do they record the local paleobathymetry of Oceanus Borealis?

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Parker, T. J.; Gorsline, D. S.

1993-01-01

The use of photoclinometry and shadow measurements to determine the basin volume without linking the measurements to a global datum is described. Since the boundary, or shoreline, of the basin cannot be tied to the datum and typically has no useful local relative height to measure, what is needed is a number of measurements of the height of the paleoshorelines distributed across the basin. Photoclinometric profiles are being compiled from Viking Orbiter images of the Cydonia Mensae region, which includes images with high sun elevations, necessary to avoid shadows, and images with low sun elevations, to enable the use of shadow measurements as an independent check, at high resolution (40 to 100 m/pixel). Both asymmetric and symmetric photoclinometric profile models are being used, and the results cross checked with one another to minimize errors. An apron-height map, potentially a paleobathymetric map of part of the margin of Oceanus Borealis, can be compiled from this data to determine whether variations in apron height are consistent with a lacustrine interpretation.

Velocity-porosity relationships for slope apron and accreted sediments in the Nankai Trough Seismogenic Zone Experiment, Integrated Ocean Drilling Program Expedition 315 Site C0001

Science.gov (United States)

Hashimoto, Y.; Tobin, H. J.; Knuth, M.

2010-12-01

In this study, we focused on the porosity and compressional wave velocity of marine sediments to examine the physical properties of the slope apron and the accreted sediments. This approach allows us to identify characteristic variations between sediments being deposited onto the active prism and those deposited on the oceanic plate and then carried into the prism during subduction. For this purpose we conducted ultrasonic compressional wave velocity measurements on the obtained core samples with pore pressure control. Site C0001 in the Nankai Trough Seismogenic Zone Experiment transect of the Integrated Ocean Drilling Program is located in the hanging wall of the midslope megasplay thrust fault in the Nankai subduction zone offshore of the Kii peninsula (SW Japan), penetrating an unconformity at ˜200 m depth between slope apron sediments and the underlying accreted sediments. We used samples from Site C0001. Compressional wave velocity from laboratory measurements ranges from ˜1.6 to ˜2.0 km/s at hydrostatic pore pressure conditions estimated from sample depth. The compressional wave velocity-porosity relationship for the slope apron sediments shows a slope almost parallel to the slope for global empirical relationships. In contrast, the velocity-porosity relationship for the accreted sediments shows a slightly steeper slope than that of the slope apron sediments at 0.55 of porosity. This higher slope in the velocity-porosity relationship is found to be characteristic of the accreted sediments. Textural analysis was also conducted to examine the relationship between microstructural texture and acoustic properties. Images from micro-X-ray CT indicated a homogeneous and well-sorted distribution of small pores both in shallow and in deeper sections. Other mechanisms such as lithology, clay fraction, and abnormal fluid pressure were found to be insufficient to explain the higher velocity for accreted sediments. The higher slope in velocity-porosity relationship for

Effective dose estimation from the Hp(10) value measured by film OR TL dosemeter located above the lead apron in medical diagnostic and intervention radiology

International Nuclear Information System (INIS)

Trousil, J.; Plichta, J.; Petrova, K.

2001-01-01

In medical institutions where the diagnostic and intervention radiology is examined the staff personnel doses reach for a long time the annual limit. State Office for Radiation Safety ordered the research task with a view to: (a) the influence of the dosemeter location on different parts of the body on the reliability of E value estimation by means of the value which is measured on the standard body location - left part of the chest above the lead apron. (b) the influence of the protective lead apron (neck, spectacles) with known lead equivalent on the E and H T value determination. In this contribution we present the results of this experimental study including the recommendation for the number and location on the body of dosemeters which are needed for the reliable estimation of E value. (authors)

Sedimentation in a Submarine Seamount Apron at Site U1431, International Ocean Discovery Program Expedition 349, South China Sea

Science.gov (United States)

Dadd, K. A.; Clift, P. D.; Hyun, S.; Jiang, T.; Liu, Z.

2014-12-01

International Ocean Discovery Program (IODP) Expedition 349 Site U1431 is located near the relict spreading ridge in the East Subbasin of the South China Sea. Holes at this site were drilled close to seamounts and intersected the volcaniclastic apron. Volcaniclastic breccia and sandstone at Site U1431 are dated as late middle Miocene to early late Miocene (~8-13 Ma), suggesting a 5 m.y. duration of seamount volcanism. The apron is approximately 200 m thick and is sandwiched between non-volcaniclastic units that represent the background sedimentation. These comprise dark greenish gray clay, silt, and nannofossil ooze interpreted as turbidite and hemipelagic deposits that accumulated at abyssal water depths. At its base, the seamount sequence begins with dark greenish gray sandstone, siltstone, and claystone in upward fining sequences interpreted as turbidites intercalated with minor intervals of volcaniclastic breccia. Upsection the number and thickness of breccia layers increases with some beds up to 4.8 m and possibly 14.5 m thick. The breccia is typically massive, ungraded, and poorly sorted with angular to subangular basaltic clasts, as well as minor reworked subrounded calcareous mudstone, mudstone, and sandstone clasts. Basaltic clasts include nonvesicular aphyric basalt, sparsely vesicular aphyric basalt, highly vesicular aphyric basalt, and nonvesicular glassy basalt. Mudstone clasts are clay rich and contain foraminifer fossils. The matrix comprises up to 40% of the breccia beds and is a mix of clay, finer grained altered basalt clasts, and mafic vitroclasts with rare foraminifer fossils. Some layers have calcite cement between clasts. Volcaniclastic sandstone and claystone cycles interbedded with the breccia layers have current ripples and parallel laminations indicative of high-energy flow conditions during sedimentation. The breccia beds were most likely deposited as a series of debris flows or grain flows. This interpretation is supported by their

Appraisal of the Psychiatric Diagnostic Screening Questionnaire in a perinatal cohort: The APrON study.

Science.gov (United States)

Leung, Brenda; Letourneau, Nicole; Bright, Katherine; Giesbrecht, Gerald F; Ntanda, Henry; Gagnon, Lisa

2017-08-01

Depression and anxiety are routinely screened as part of perinatal care. However, other Axis 1 disorders and specific anxiety disorders are less likely to be screened or assessed as part of obstetric care. The objective of this study was to determine whether the Psychiatric Diagnostic Screening Questionnaire (PDSQ) is a potentially useful tool to screen for psychiatric conditions in pregnant and postpartum women in a community setting. We compared the prevalence of DSM Axis I disorders obtained on the PDSQ with: (1) the prevalence of these disorders reported in previous studies of pregnant and postpartum women, and (2) scores obtained on the Edinburgh Postpartum Depression Scale (EPDS) and the Symptom Checklist-90-Revised (SCL-90R) anxiety scale. Data were obtained from the Alberta Pregnancy Outcomes and Nutrition (APrON) study. The PDSQ was completed by 1575 women prenatally and 1481 postnatally. The three most prevalent PDSQ conditions were social phobia, somatic disorder, and obsessive-compulsive disorder (OCD). The prevalence of social phobia, alcohol disorder, OCD and psychosis were higher in the APrON cohort compared with statistics in the literature. The proportion of women meeting depression and anxiety cut-offs on the PDSQ were lower than for the EPDS and the SCL-90R. The Cohens Kappa index ( k) indicated poor to fair agreement between the measures in classifying pregnant women as depressed or anxious. The PDSQ subscales may not be appropriate for the pregnant population. Research into instruments more specific to pregnant and postpartum women are needed to determine the prevalence of psychiatric disorders in this population.

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.

Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics?

Science.gov (United States)

Kristensen, Lene; Benn, Douglas I.; Hormes, Anne; Ottesen, Dag

2009-10-01

Large debris-flow units commonly occur on the distal sides of subaqueous end moraines deposited by surges of Svalbard tidewater glaciers, but have rarely been described in terrestrial settings. Some researchers have argued that these kinds of debris flows reflect processes unique to the subaqueous environment, such as the extrusion of subglacial deforming layers or extensive failure of oversteepened moraine fronts. In this paper, we describe terrestrial and subaqueous parts of a single late Holocene moraine system deposited by a major surge of the tidewater glacier Paulabreen in west Spitsbergen. The ice-marginal landforms on land closely resemble the corresponding landforms on the seabed as evidenced by geomorphic mapping and geophysical profiles from both environments. Both onland and offshore, extensive areas of hummocky moraine occur on the proximal side of the maximum glacier position, and large mud aprons (interpreted as debris flows) occur on the distal side. We show that the debris-flow sediments were pushed in front of the advancing glacier as a continuously failing, mobile push moraine. We propose that the mud aprons are end members of a proglacial landforms continuum that has thrust-block moraines as the opposite end member. Two clusters of dates (~ 8000 YBP and ~ 700 YBP) have previously been interpreted to indicate two separate surges responsible for the moraine formation. New dates suggest that the early cluster indicates a local extinction of the abounded species Chlamys islandica. Other changes corresponding to the widespread 8.2 ka event within the fjord, may suggest that the extinction of the C. islandica corresponds to that time.

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

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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.

Evidence for Late Pleistocene uplift at the Somma-Vesuvius apron near Pompeii

Science.gov (United States)

Marturano, Aldo; Aiello, Giuseppe; Barra, Diana

2011-05-01

Detailed stratigraphic and micropalaeontological analyses of samples from boreholes at the Somma-Vesuvius apron, between Pompeii and the sea, allowed reconstruction of Late Quaternary palaeoenvironmental evolution of the Sarno coastal plain. In all, 116 samples were recovered from seven boreholes drilled from 2-10 m a.s.l. to 16.5-26 m b.s.l. Microfossil assemblages, with special regard to benthic foraminifers and ostracods, were used to reconstruct the depositional palaeoenvironment. Fossil remains show that all the pre-79 AD fossiliferous sediments from 2 to - 24 m a.s.l. were deposited in shallow marine waters for a long time despite an appreciable sea level rise. The data indicate alternation of both shallow marine and subaerial conditions during the last ~ 15 kyr, evidencing ground uplift of the area of about 75 m at a rate of ~ 5 mm/year. Marine sediment accumulation (~ 6 m/kyr) and tectonic uplift long offset the sea level rise, and as a consequence, submerged areas remained the same as well.

Radiation exposure of radiologists during angiography: Dose measurements outside the lead apron; Die Strahlenexposition des Radiologen bei Angiographien: Dosismessungen ausserhalb der Bleischuerze

Energy Technology Data Exchange (ETDEWEB)

Fischer, H. [Inst. fuer Diagnostische Radiologie, Duesseldorf Univ. (Germany); Przetak, C. [Inst. fuer Diagnostische Radiologie, Duesseldorf Univ. (Germany); Teubert, G. [Landesanstalt fuer Arbeitsschutz, Duesseldorf (Germany); Ewen, K. [Landesanstalt fuer Arbeitsschutz, Duesseldorf (Germany); Moedder, U. [Inst. fuer Diagnostische Radiologie, Duesseldorf Univ. (Germany)

1995-02-01

The aim of this study was to provide practical information to angiographers concerning radiation exposure to body parts not covered by lead aprons. Individual doses to the neck and hands of radiologists measured in micro-Sieverts were obtained during the course of 80 angiographies of various types. The number of diagnostic and interventional procedures, which might lead to exceeding permissible doses, have been calculated. Possibilities of estimating doses during angiography by means of parameters such as screening times were examined statistically. Especially with regard to the hands, estimations of the doses are insufficient (correlation r=0.21). Radiologists who undertake much angiographic and particularly interventional work may reach exposure levels requiring protective measures in addition to lead aprons. (orig.) [Deutsch] Ziel dieser Studie ist es, dem angiographierenden Radiologen praktische Anhaltspunkte zur Einschaetzung der Strahlenexposition der nicht von der Bleischuerze abgedeckten Koerperteile zu geben. Bei 80 Angiographien aus einem breiten klinischen Spektrum wurden Einzeldosen in Mikro-Sievert an Hals und Hand des Radiologen gemessen. Fuer bestimmte Gruppen von diagnostischen und interventionellen Angiographien wurde die Anzahl der Untersuchungen hochgerechnet, die zu einer Ueberschreitung der Grenzwerte fuehren koennte. Die Moeglichkeit einer Schaetzung der Dosis anhand von Parametern der Angiographie, wie z.B. der Durchleuchtungszeit, wurde korrelationsstatistisch geprueft. Besonders fuer die Haende ist eine Schaetzung unzureichend (r=0,21). Kontinuierlich und viel angiographiende Radiologen koennen im diagnostischen, aber eher noch im interventionellen Bereich eine Groessenordnung erreichen, die Vorsichtsmassnahmen oder Zusatzmessungen ausserhalb der Bleischuerze sinnvoll erscheinen laesst. (orig.)

Study on reducing radiation dose in dental radiography for children, 1. The seltering effects of lead content rubber sheet and ready-made apron

Energy Technology Data Exchange (ETDEWEB)

Shikone, Mitsuru; Tsuchida, Atsushi; Tateno, Hidemi; Uchimura, Noboru; Higaki, Morio; Kanno, Masanori; Higashi, Tomomitsu

1986-12-01

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.

Hydrodynamic conditions on the slope apron of a rapid hydraulic structure (RHS) and within the influence of it - an example from the Czarny Dunajec River, Polish Carpathians.

Science.gov (United States)

Plesiński, Karol; Radecki-Pawlik, Artur

2013-04-01

The paper focuses on understanding some basic hydrodynamic conditions along a regulated river engineered with rapid hydraulic structures (RHS) - the modern hydraulic structure used in river engineering works, to reduce slope of the river bed, stabilize it and reducing river channel bed erosion, at the same time structures being friendly to river environment, allowing fish and invertebrate to migrate and built according the expectations of River Framework Directive EU. The measurements were performed upstream and downstream of RHS within the influence of the structure as well as on the slope apron of the structure where the artificial roughness is created by fixing along all the apron very coarse gravel and small boulders to make the RHS similar to natural rapids in a gravel river. It the field, we measured water depth h, average velocity Va, maximum velocity Vm for different discharges, near bed velocities and all geometry of the RHS. The value of these parameters were used to calculate the shear velocity V*, shear stresses ?, Reynolds number and Froude number. Using our results, we observed that there is a greater range of the values of hydrodynamic parameters downstream of the RHS, where braids and small channels are formed, although this section of a river was engineered. The values of velocities were varied here as follows: Va = 0.194 - 2.210 m s-1 for a high water level and Va = 0.104 - 1.720 m s-1 for a low water level. Consequently, the values of shear stresses were varied here between ? = 0.106 - 4.720 N m-2and ? = 0.013 - 6.084 N m-2 respectively for a high and a low water level. Then, upstream of the RHS, the values of these parameters were comparable. The values of velocities were here as follows: Va = 0.264 - 0.590 m s-1 for a high water level and Va = 0.066 - 0.346 m s-1 for a low water level. And, the values of shear stresses were noticed here as: ? = 0.067 - 0.660 N m-2 and ? = 0.009 - 0.269 N m-2 respectively for high and low water level. Downstream

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

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.

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

International Nuclear Information System (INIS)

Pifarre, X.; Brualla, L.; Ruiz, J.; Escalada, C.; Planes, D.; Paredes, M.C.

2001-01-01

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)

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.

IMPROVING CHILDREN‘S SPEECH SKILLS USE MEDIA-ASSISTED STORY TELLING WITH STORY APRONS AND HAND PUPPETS

Directory of Open Access Journals (Sweden)

Radeni Sukma Indra Dewi

2017-12-01

Full Text Available Problem in this study regarding the lack of language profieciency, especially in speaking skills. This study aims to determine the speaking skills improvement after application of media-aided Story Aprons and Hand Puppets in the second semester of children in group B3 in kindergarten Pertiwi 45 academic year 2016/2017. This research is a classroom action research conducted in two cycles. The subjects were 31 children in group B3 in the second semester of kindergarten Pertiwi 45 in academic year 2016/2017, which consists of 16 girl and 15 boys. Data collected research on speaking skill with observation form sheet format. Data were analyzed using descriptive statistical analysis and quantitative descriptive analysis method. The result showed that an increase speaking skill by applying the method of storytelling assisted hand puppet media in the first cycle of 63,31% which is at the low category had experienced an increase in the second cycle into 80,81% were classified in the high category. Based on the results of the research and the analysis increased ability to speak at 17,50% of children in group B3 kindergarten Pertiwi 45 Semarang.

The Development of 3d Sub-Surface Mapping Scheme and its Application to Martian Lobate Debris Aprons

Science.gov (United States)

Baik, H.; Kim, J.

2017-07-01

The Shallow Subsurface Radar (SHARAD), a sounding radar equipped on the Mars Reconnaissance Orbiter (MRO), has produced highly valuable information about the Martian subsurface. In particular, the complicated substructures of Mars such as polar deposit, pedestal crater and the other geomorphic features involving possible subsurface ice body has been successfully investigated by SHARAD. In this study, we established a 3D subsurface mapping strategy employing the multiple SHARAD profiles. A number of interpretation components of SHARAD signals were integrated into a subsurface mapping scheme using radargram information and topographic data, then applied over a few mid latitude Lobate Debris Aprons (LDAs). From the identified subsurface layers of LDA, and the GIS data base incorporating the other interpretation outcomes, we are expecting to trace the origin of LDAs. Also, the subsurface mapping scheme developed in this study will be further applied to other interesting Martian geological features such as inter crater structures, aeolian deposits and fluvial sediments. To achieve higher precision sub-surface mapping, the clutter simulation employing the high resolution topographic data and the upgraded clustering algorithms assuming multiple sub-surface layers will be also developed.

Environmental Assessment for Building 88 Interior Demolition, Pearl Harbor Naval Complex, O'ahu, Hawaii

National Research Council Canada - National Science Library

2005-01-01

...) and ancillary equipment from the interior of Building 88, a former lubricating oil storage facility, and the related exposed piping underneath Mike wharves M3 and M4 at Merry Point, Pearl Harbor Naval Complex...

Slope-apron deposition in an ordovician arc-related setting: The Vuelta de Las Tolas Member (Suri Formation), Famatina Basin, northwest Argentina

Science.gov (United States)

Mangano, M.G.; Buatois, L.A.

1997-01-01

The Ordovician Suri Formation is part of the infill of the Famatina Basin of northwest Argentina, which formed in an active setting along the western margin of early Paleozoic Gondwana. The lower part of this formation, the Vuelta de Las Tolas Member, records sedimentation on a slope apron formed in an intra-arc basin situated on a flooded continental arc platform. The coincidence of a thick Arenig-Llanvirn sedimentary succession and volcanic-plutonic arc rocks suggests an extensional or transtensional arc setting, and is consistent with evidence of an extensional regime within the volcanic arc in the northern Puna region. The studied stratigraphic sections consist of volcanic rocks and six sedimentary facies. The facies can be clustered into four facies associations. Association 1, composed of facies A (laminated siltstones and mudstones) and B (massive mudstones and siltstones), is interpreted to have accumulated from silty-muddy high-and low-density turbidity currents and highly fluid, silty debris flows, with subsequent reworking by bottom currents, and to a lesser extent, hemipelagic suspension in an open-slope setting. Facies association 2 is dominated by facies C (current-rippled siltstones) strata. These deposits are interpreted to record overbank sedimentation from fine-grained turbidity currents. Facies E (matrix-supported volcanic breccias) interbedded with andesitic lava units comprises facies association 3. Deposition was contemporaneous with subaqueous volcanic activity, and accumulated from cohesive debris flows in a coarse-grained wedge at the base of slope. Facies association 4 is typified by facies D (vitric fine-grained sandstones and siltstones) and F (channelized and graded volcanic conglomerates and breccias) deposits. These strata commonly display thinning-and fining-upward trends, indicating sedimentation from highly-concentrated volcaniclastic turbidity currents in a channelized system. The general characteristics of these deposits of fresh

Evaluation of the Occupational Doses of Interventional Radiologists

International Nuclear Information System (INIS)

Kuipers, Gerritjan; Velders, Xandra L.; Winter, Robbert J. de; Reekers, Jim A.; Piek, Jan J.

2008-01-01

The aim of the present study was to determine whether there is a linear relation between the doses measured above and those measured under the lead apron of the radiologists performing interventional procedures. To monitor radiation exposure the International Commission of Radiological Protection (ICRP) recommends the use of a single dosimeter under the protective apron. To determine the exposure more accurately an additional dosimeter is recommended above the protective apron. The exposure of eight radiologists was monitored with two personal dosimeters during 3 consecutive years. To measure the doses uniformly the two dosimeters were worn in a special holder attached to the lead apron. The two personal dosimeters were replaced every 4 weeks on the same day. The doses above and under the protective aprons of seven radiologists did not differ significantly. A significant lower dose above and under the protective apron was measured for one of the radiologists. During a 4-week period the average dose measured above the lead apron was 3.44 mSv (median, 3.05 mSv), while that under the 0.25-mm lead apron was 0.12 mSv (median, 0.1 mSv). The coefficients of the regression line result in the equation Y = 0.036X - 0.004, with Y as the dose under the lead apron and X as the dose above the lead apron. The statistical analysis of the data established a linear relation between the doses above and those under the lead apron (R 2 = 0.59). Before the special holder was introduced it was not possible to derive a relation between the doses above and those under the lead apron, as the doses were measured at varying places above and under the lead apron. There is no evidence that the effective dose can be estimated more accurately when an additional dosimeter is used. The present study revealed a threshold before doses under the lead apron were measured. Due to the threshold it can be concluded that the doses under the lead apron will not be underestimated easily when doses above the

Personnel dosimetry in fluoroscopy

International Nuclear Information System (INIS)

Baechler, S.; Gardon, M.; Bochud, F.; Sans-Merce, M.; Verdun, F.R.; Trueb, Ph.

2006-01-01

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)

Town and Citadel of Quebec

OpenAIRE

Vallée Louis-Prudent, 1837-1905, photographer

2003-01-01

230 x 176 mm. A view looking across the St. Lawrence towards the town and Citadel of Quebec, with shipping at anchor in the river. A photograph taken from the Grand Trunk Railway Depot, Point Lewis, probably in 1870. In the foreground railway lines run down to wharves beside the terminal.

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

International Nuclear Information System (INIS)

Damet, J.; Bailat, C.; Bize, P.; Buchillier, Th.; Tosic, M.; Verdun, F.R.; Baechler, S.

2011-01-01

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.

Constraints on martian lobate debris apron evolution and rheology from numerical modeling of ice flow

Science.gov (United States)

Parsons, Reid A.; Nimmo, Francis; Miyamoto, Hideaki

2011-07-01

Radar observations in the Deuteronilus Mensae region by Mars Reconnaissance Orbiter have constrained the thickness and dust concentration found within mid-latitude ice deposits, providing an opportunity to more accurately estimate the rheology of ice responsible for the formation of lobate debris aprons based on their apparent age of ˜100 Myr. We developed a numerical model simulating ice flow under martian conditions using results from ice deformation experiments, theory of ice grain growth based on terrestrial ice cores, and observational constraints from radar profiles and laser altimetry. By varying the ice grain size, the ice temperature, the subsurface slope, and the initial ice volume we determine the combination of parameters that best reproduce the observed LDA lengths and thicknesses over a period of time comparable to the apparent ages of LDA surfaces (90-300 Myr). We find that an ice temperature of 205 K, an ice grain size of 5 mm, and a flat subsurface slope give reasonable ages for many LDAs in the northern mid-latitudes of Mars. Assuming that the ice grain size is limited by the grain boundary pinning effect of incorporated dust, these results limit the dust volume concentration to less than 4%. However, assuming all LDAs were emplaced by a single event, we find that there is no single combination of grain size, temperature, and subsurface slope which can give realistic ages for all LDAs, suggesting that some or all of these variables are spatially heterogeneous. Based on our model we conclude that the majority of northern mid-latitude LDAs are composed of clean (⩽4 vol%), coarse (⩾1 mm) grained ice, but regional differences in either the amount of dust mixed in with the ice, or in the presence of a basal slope below the LDA ice must be invoked. Alternatively, the ice temperature and/or timing of ice deposition may vary significantly between different mid-latitude regions. Either eventuality can be tested with future observations.

Predictors of exclusive breastfeeding: observations from the Alberta pregnancy outcomes and nutrition (APrON) study.

Science.gov (United States)

Jessri, Mahsa; Farmer, Anna P; Maximova, Katerina; Willows, Noreen D; Bell, Rhonda C

2013-05-16

Despite growing evidence that supports the importance of 6-month exclusive breastfeeding, few Canadian mothers adhere to this, and early weaning onto solids is a common practice. This study assessed infant feeding transitions during the first 6 months postpartum and factors that predicted exclusive breastfeeding to 3 and 6 months. This prospective cohort study was part of the Alberta Pregnancy Outcomes and Nutrition study (APrON). From an initial sample of 600 pregnant women recruited from Edmonton and Calgary, 402 mothers provided complete details at 3 months postpartum; 300 stayed on to provide information at 6 months postpartum. During pregnancy and at 3 and 6 months postpartum, data on maternal and infant socio-demographic, behavior, and feeding were collected. Even though there was a high rate of "ever having breastfed" (98.6%), exclusive breastfeeding rates for 3 and 6 months were 54.0% and 15.3%, respectively. After controlling for potential confounders, the study showed that mothers who held post-graduate university degrees were 3.76 times more likely to breastfeed exclusively for 6 months than those without a university degree (95% CI: 1.30-10.92; p = 0.015). In addition, mother of previous children were more likely to breastfeed exclusively for 6 months (OR: 2.21, 95% CI: 1.08-4.52; p = 0.031). Mothers who were in the highest quartile of the Iowa Infant Feeding Attitude Score were 4.29 and 5.40 times more likely to breastfeed exclusively for 3 months (95% CI: 1.31-14.08; p-trend < 0.001) and 6 months (95% CI: 2.75-10.60; P-trend < 0.001), respectively. The 6-month exclusive breastfeeding rate in Alberta is considerably below national and international breastfeeding recommendations. Professional advice that focuses on prenatal maternal knowledge, attitudes, and misperceptions may promote adherence to World Health Organization breastfeeding guidelines. Knowing that exclusive breastfeeding is less likely to take place among lower

Predictors of exclusive breastfeeding: observations from the Alberta pregnancy outcomes and nutrition (APrON) study

Science.gov (United States)

2013-01-01

Background Despite growing evidence that supports the importance of 6-month exclusive breastfeeding, few Canadian mothers adhere to this, and early weaning onto solids is a common practice. This study assessed infant feeding transitions during the first 6 months postpartum and factors that predicted exclusive breastfeeding to 3 and 6 months. Methods This prospective cohort study was part of the Alberta Pregnancy Outcomes and Nutrition study (APrON). From an initial sample of 600 pregnant women recruited from Edmonton and Calgary, 402 mothers provided complete details at 3 months postpartum; 300 stayed on to provide information at 6 months postpartum. During pregnancy and at 3 and 6 months postpartum, data on maternal and infant socio-demographic, behavior, and feeding were collected. Results Even though there was a high rate of “ever having breastfed” (98.6%), exclusive breastfeeding rates for 3 and 6 months were 54.0% and 15.3%, respectively. After controlling for potential confounders, the study showed that mothers who held post-graduate university degrees were 3.76 times more likely to breastfeed exclusively for 6 months than those without a university degree (95% CI: 1.30-10.92; p = 0.015). In addition, mother of previous children were more likely to breastfeed exclusively for 6 months (OR: 2.21, 95% CI: 1.08-4.52; p = 0.031). Mothers who were in the highest quartile of the Iowa Infant Feeding Attitude Score were 4.29 and 5.40 times more likely to breastfeed exclusively for 3 months (95% CI: 1.31-14.08; p-trend breastfeeding rate in Alberta is considerably below national and international breastfeeding recommendations. Professional advice that focuses on prenatal maternal knowledge, attitudes, and misperceptions may promote adherence to World Health Organization breastfeeding guidelines. Knowing that exclusive breastfeeding is less likely to take place among lower-educated, primiparous women may help health practitioners focus their

Feasibility of implementation of a "simplified, No-X-Ray, no-lead apron, two-catheter approach" for ablation of supraventricular arrhythmias in children and adults.

Science.gov (United States)

Stec, Sebastian; Śledź, Janusz; Mazij, Mariusz; Raś, Małgorzata; Ludwik, Bartosz; Chrabąszcz, Michał; Śledź, Arkadiusz; Banasik, Małgorzata; Bzymek, Magdalena; Młynarczyk, Krzysztof; Deutsch, Karol; Labus, Michał; Śpikowski, Jerzy; Szydłowski, Lesław

2014-08-01

Although the "near-zero-X-Ray" or "No-X-Ray" catheter ablation (CA) approach has been reported for treatment of various arrhythmias, few prospective studies have strictly used "No-X-Ray," simplified 2-catheter approaches for CA in patients with supraventricular tachycardia (SVT). We assessed the feasibility of a minimally invasive, nonfluoroscopic (MINI) CA approach in such patients. Data were obtained from a prospective multicenter CA registry of patients with regular SVTs. After femoral access, 2 catheters were used to create simple, 3D electroanatomic maps and to perform electrophysiologic studies. Medical staff did not use lead aprons after the first 10 MINI CA cases. A total of 188 patients (age, 45 ± 21 years; 17% 0.05), major complications (0% vs. 0%, P > 0.05) and acute (98% vs. 98%, P > 0.05) and long-term (93% vs. 94%, P > 0.05) success rates were similar in the "No-X-Ray" and control groups. Implementation of a strict "No-X-Ray, simplified 2-catheter" CA approach is safe and effective in majority of the patients with SVT. This modified approach for SVTs should be prospectively validated in a multicenter study. © 2014 Wiley Periodicals, Inc.

Reduction of uterus dose in clinical thoracic computed tomography

International Nuclear Information System (INIS)

Danova, D.; Keil, B.; Kaestner, B.; Klose, K.J.; Heverhagen, J.T.; Wulff, J.; Fiebich, M.; Zink, K.

2010-01-01

Purpose: The aim of this study was to investigate the potential dose reduction in the uterus as a result of lead apron protection during thoracic CT scans. Moreover, the distribution of the radiation dose in the uterus was determined in order to obtain information about the ratio of internally and externally scattered radiation. Materials and Methods: The uterus doses during thoracic CT were determined by measuring organ doses using an Alderson-RANDO registered -Phantom and thermoluminescent dosimeters. A 0.25 mm lead equivalent protective apron was used to shield the abdominal area. Three measurement conditions were evaluated: without lead apron, covered with lead apron and wrapped with lead apron. The uterus dose with and without shielding describes the mean value and standard deviation of all examinations and all measurement points in the organ. Results: The uterus dose by thoracic CT was measured to be approximately 66.5 ± 3.1 μGy. If the abdomen is covered with a 0.25 mm Pb equivalent lead apron in the front area and on both sides, the uterus dose is reduced to 49.4 ± 2.8 μGy (26 % reduction, p < 0.001). If a lead apron is wrapped around the abdomen, providing 0.50 mm Pb shielding in the anterior section due to overlap, and 0.25 mm Pb in the posterior section and on both sides, the uterus dose is reduced even more to 43.8 ± 2.5 μGy (34 % reduction, p < 0.001). The dose distribution when the lead apron covers the abdomen shows that the shielding is effective for the scatter radiation that comes from the anterior part. Moreover, the wrapped apron protects the uterus from all directions and is even more effective for dose reduction than the covering apron. Conclusion: Our findings demonstrate that protective aprons are an effective dose reduction technique without additional costs and little effect on patient examination time. (orig.)

Investigation of radiation exposure dosage in dental and panoramic radiography

International Nuclear Information System (INIS)

Ishii, Kenichi

2005-01-01

Dental radiography and a 10-sheet procedure were conducted at 10 sites in the maxillomandibular anterior teeth and at both sides of the premolar and molar teeth sections with and without a protective apron (total 22 patterns). Experiments, which included a total of five patterns, involving standard ortho-radiography were performed with and without a protective apron, positioning of an apron exclusively on the anterior or the posterior portion of the body and utility of an apron that covered the entire body. Results are as follows: In dental radiography, internal organs included in a bundle demonstrated high radiation exposure, whereas organs excluded from the bundle exhibited low radiation exposure. In organs situated below the thyroid gland, utilization of aprons resulted in lower radiation exposure. In ortho-radiography, radiation exposure was greatest in the parotid gland, followed by the mandibular, sublingual and thyroid glands, respectively. The protective apron resulted in lower radiation exposure at sites situated below the mammary glands; moreover, a protector covering the entire body led to lower radiation exposure in comparison to an apron worn exclusively on the anterior or the posterior aspect of the body. No significant difference was observed in terms of exposure between protective aprons worn on the anterior or the posterior aspect of the body. Furthermore, a protective collar resulted in nearly zero radiation exposure in the thyroid gland. However, a protective collar largely interferes with interpretation of the radiograph; thus, in order to produce interpretable radiographs, protection of the thyroid gland is not possible. In conclusion, radiation exposure dosage can be reduced via utilization of a protective apron positioned below the thyroid gland during dental radiography and below the mammary glands during ortho-radiography. We confirmed evidence indicating that application of a protective apron can reduce patient radiation exposure dosage

Strong Motion Instrumentation of Seismically-Strengthened Port Structures in California by CSMIP

Science.gov (United States)

Huang, M.J.; Shakal, A.F.

2009-01-01

The California Strong Motion Instrumentation Program (CSMIP) has instrumented five port structures. Instrumentation of two more port structures is underway and another one is in planning. Two of the port structures have been seismically strengthened. The primary goals of the strong motion instrumentation are to obtain strong earthquake shaking data for verifying seismic analysis procedures and strengthening schemes, and for post-earthquake evaluations of port structures. The wharves instrumented by CSMIP were recommended by the Strong Motion Instrumentation Advisory Committee, a committee of the California Seismic Safety Commission. Extensive instrumentation of a wharf is difficult and would be impossible without the cooperation of the owners and the involvement of the design engineers. The instrumentation plan for a wharf is developed through study of the retrofit plans of the wharf, and the strong-motion sensors are installed at locations where specific instrumentation objectives can be achieved and access is possible. Some sensor locations have to be planned during design; otherwise they are not possible to install after construction. This paper summarizes the two seismically-strengthened wharves and discusses the instrumentation schemes and objectives. ?? 2009 ASCE.

Exposure doses to angiographers during interventional angiography

International Nuclear Information System (INIS)

Fukutomi, Yukimi; Yasuhara, Yoshifumi; Sugata, Shigenori; Fujii, Takashi; Kawakami, Toshiaki; Ikezoe, Junpei

1997-01-01

We report the exposure doses to angiographers during interventional angiography and the protective efficacy of protective aprons against X-rays in this study. The first (main) angiographer was exposed to the maximum dose of 1 μSv/min at the left chest area and lower abdominal area inside the protective apron. The second (assistant) angiographer was exposed to the maximum dose of 2 μSv/min at the left chest area and 1 μSv/min at the lower abdominal area. X-ray transmission ratio of the protective apron was 4.9 percent or less for UL25L, O percent for 0.35 mmPb and 4.3 percent or less for 0.5 mmPb. These results were lower than the dose equivalent limit based on the laws and ordinances. The protection capacities of these protective aprons proved to be sufficient. The exposure dose at the left extremity area outside the protective apron, however, was 24 times higher than at the left chest area inside. The data showed that it was not protected from scattered X-rays outside the protective apron. It is imperative to consider secondary protective material for the area outside the protective apron. Considering the risk of radiation, we need to better control exposure to angiographers. (author)

Use of micronutrient supplements among pregnant women in Alberta: results from the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort.

Science.gov (United States)

Gómez, Mariel Fajer; Field, Catherine J; Olstad, Dana Lee; Loehr, Sarah; Ramage, Stephanie; McCargar, Linda J

2015-10-01

Maternal nutrient intake in the prenatal period is an important determinant of fetal growth and development and supports maternal health. Many women, however, fail to meet their prenatal nutrient requirements through diet alone and are therefore advised to consume nutrient supplements. The purpose of this study was to describe the use of natural health products (NHP) by pregnant women in each trimester of pregnancy. Women (n = 599) participating in the first cohort of the Alberta Pregnancy Outcomes and Nutrition (APrON) study completed an interviewer-administered supplement intake questionnaire during each trimester of pregnancy. NHP use was high, with >90% taking multivitamin/mineral supplements, and nearly half taking at least one additional single-nutrient supplement. Compliance with supplementation guidelines was high for folic acid (>90%), vitamin D (∼70%) and calcium (∼80%), but low for iron (<30%) and for all four nutrients together (≤11%). On average, women met or exceeded the recommended dietary allowance for folic acid, vitamin D and iron from NHPs alone, with median daily intakes of 1000 μg, 400 IU and 27 mg, respectively. The median calcium intake was 250 mg d(-1) . Up to 26% of women exceeded the tolerable upper intake level for folic acid and up to 19% did so for iron at some point of their pregnancy. Findings highlight the need to consider both dietary and supplemental sources of micronutrients when assessing the nutrient intakes of pregnant women. © 2013 John Wiley & Sons Ltd.

Folate, vitamin B12, and vitamin B6 status of a group of high socioeconomic status women in the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort.

Science.gov (United States)

Fayyaz, Faiqa; Wang, Flora; Jacobs, René L; O'Connor, Deborah L; Bell, Rhonda C; Field, Catherine J

2014-12-01

Folic acid supplementation and food fortification policies have improved folate status in North American women of child bearing age. Recent studies have reported the possible inadequacy of vitamin B12 and B6 in the etiology of neural tube defects in folate-fortified populations. The aims of this study were to describe folate status and its relationship to supplementation and to assess vitamin B12 and B6 status in a cohort of pregnant women. Supplement intake data were collected in each trimester from the first cohort (n = 599) of the Alberta Pregnancy Outcomes and Nutrition (APrON) study. Red blood cell folate (RBCF) and plasma folate, holotranscobalamin, and pyridoxal 5-phosphate were measured. Overt folate deficiency was rare (3%) but 24% of women in their first trimester had suboptimal RBCF concentration (1360 nmol·L(-1)) was observed in approximately half of the women during each pregnancy trimester. Vitamin B12 and B6 deficiencies were rare (pregnancy and over half the women had abnormally high RBCF, suggesting that supplementation during pregnancy is not appropriate in a cohort of women considered to be healthy and a low risk for nutritional deficiencies.

Is lead shielding of patients necessary during fluoroscopic procedures? A study based on kyphoplasty

Energy Technology Data Exchange (ETDEWEB)

Smith, Joshua R.; Marsh, Rebecca M.; Silosky, Michael S. [University of Colorado School of Medicine, Department of Radiology, Aurora, CO (United States)

2018-01-15

To determine the benefits, risks, and limitations associated with wrapping a patient with lead shielding during fluoroscopy-guided kyphoplasty procedures as a way to reduce operator radiation exposure. An anthropomorphic phantom was used to mimic a patient undergoing a kyphoplasty procedure under fluoroscopic guidance. Radiation measurements of the air kerma rate (AKR) were made at several locations and under various experimental conditions. First, AKR was measured at various angles along the horizontal plane of the phantom and at varying distances from the phantom, both with and without a lead apron wrapped around the lower portion of the phantom (referred to here as phantom shielding). Second, the effect of an operator's apron was simulated by suspending a lead apron between the phantom and the measurement device. AKR was measured for the four shielding conditions - phantom shielding only, operator apron only, both phantom shielding and operator apron, and no shielding. Third, AKR measurements were made at various heights and with varying C-arm angle. At all locations, the phantom shielding provided no substantial protection beyond that provided by an operator's own lead apron. Phantom shielding did not reduce AKR at a height comparable to that of an operator's head. Previous reports of using patient shielding to reduce operator exposure fail to consider the role of an operator's own lead apron in radiation protection. For an operator wearing appropriate personal lead apparel, patient shielding provides no substantial reduction in operator dose. (orig.)

Is lead shielding of patients necessary during fluoroscopic procedures? A study based on kyphoplasty

International Nuclear Information System (INIS)

Smith, Joshua R.; Marsh, Rebecca M.; Silosky, Michael S.

2018-01-01

To determine the benefits, risks, and limitations associated with wrapping a patient with lead shielding during fluoroscopy-guided kyphoplasty procedures as a way to reduce operator radiation exposure. An anthropomorphic phantom was used to mimic a patient undergoing a kyphoplasty procedure under fluoroscopic guidance. Radiation measurements of the air kerma rate (AKR) were made at several locations and under various experimental conditions. First, AKR was measured at various angles along the horizontal plane of the phantom and at varying distances from the phantom, both with and without a lead apron wrapped around the lower portion of the phantom (referred to here as phantom shielding). Second, the effect of an operator's apron was simulated by suspending a lead apron between the phantom and the measurement device. AKR was measured for the four shielding conditions - phantom shielding only, operator apron only, both phantom shielding and operator apron, and no shielding. Third, AKR measurements were made at various heights and with varying C-arm angle. At all locations, the phantom shielding provided no substantial protection beyond that provided by an operator's own lead apron. Phantom shielding did not reduce AKR at a height comparable to that of an operator's head. Previous reports of using patient shielding to reduce operator exposure fail to consider the role of an operator's own lead apron in radiation protection. For an operator wearing appropriate personal lead apparel, patient shielding provides no substantial reduction in operator dose. (orig.)

Radiation exposure to anesthesiologist and nurse in the orthopedic room

Energy Technology Data Exchange (ETDEWEB)

Arita, Tetsuhiko; Matsuzaki, Akio [Fukuoka Univ., Chikushino (Japan). Chikusi Hospital

1996-09-01

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 2.08{mu}SV, and in front and behind the nurse`s lead apron were 5.67{mu}SV, 0.08{mu}SV 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)

Radiation exposure to anesthesiologist and nurse in the orthopedic room

International Nuclear Information System (INIS)

Arita, Tetsuhiko; Matsuzaki, Akio

1996-01-01

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)

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

International Nuclear Information System (INIS)

Luo Suming; He Zhijian; Yuan Jilong; Yue Baorong; Wei Kedao

2011-01-01

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 125 I seed sources. Methods The experiments with 60 Co γ-rays were carried out for the stability. A group of TLD chips was exposed to 125 I seed sources to establish standard dose curve for air kerma. During the 125 I 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 125 I 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 125 I 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 125 I 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 125 Iseeds, 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 125

Exposure of the orthopaedic surgeon to radiation

Energy Technology Data Exchange (ETDEWEB)

Katoh, Kiyonobu; Koga, Takamasa; Matsuzaki, Akio; Kido, Masaki; Satoh, Tetsunori [Fukuoka Univ. (Japan). Chikushi Hospital

1995-09-01

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 {mu}SV and the average exposure for each procedure was 1.68 {mu}SV. 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 {mu}SV, the measured dose beneath the apron 0.61 {mu}SV. The average dose of exposure to the head, breast at groin level outside of the lead apron, were 7.68 {mu}SV, 16.24 {mu}SV, 32.04 {mu}SV 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).

Exposure of the orthopaedic surgeon to radiation

International Nuclear Information System (INIS)

Katoh, Kiyonobu; Koga, Takamasa; Matsuzaki, Akio; Kido, Masaki; Satoh, Tetsunori

1995-01-01

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)

Plateaus and sinuous ridges as the fingerprints of lava flow inflation in the Eastern Tharsis Plains of Mars

Science.gov (United States)

Bleacher, Jacob E.; Orr, Tim R.; de Wet, Andrew P.; Zimbelman, James R.; Hamilton, Christopher W.; Brent Garry, W.; Crumpler, Larry S.; Williams, David A.

2017-08-01

The Tharsis Montes rift aprons are composed of outpourings of lava from chaotic terrains to the northeast and southwest flank of each volcano. Sinuous and branching channel networks that are present on the rift aprons suggest the possibility of fluvial processes in their development, or erosion by rapidly emplaced lavas, but the style of lava flow emplacement throughout rift apron development is not clearly understood. To better characterize the style of lava emplacement and role of fluvial processes in rift apron development, we conducted morphological mapping of the Pavonis Mons southwest rift apron and the eastern Tharsis plains using images from the High Resolution Imaging Science Experiment (HiRISE), Mars Orbiter Camera (MOC), Context Camera (CTX), Thermal Emission Imaging System (THEMIS), and High Resolution Stereo Camera (HRSC) along with the Mars Orbiter Laser Altimeter (MOLA) Precision Experiment Data Records (PEDRs) and gridded data. Our approach was to: (1) search for depositional fans at the slope break between the rift apron and adjacent low slope plains; (2) determine if there is evidence that previously formed deposits might have been buried by plains units; (3) characterize the Tharsis plains morphologies east of Pavonis Mons; and (4) assess their relationship to the rift apron units. We have not identified topographically significant depositional fans, nor did we observe evidence to suggest that plains units have buried older rift apron units. Flow features associated with the rift apron are observed to continue across the slope break onto the plains. In this area, the plains are composed of a variety of small fissures and low shield vents around which broad channel-fed and tube-fed flows have been identified. We also find broad, flat-topped plateaus and sinuous ridges mixed among the channels, tubes and vents. Flat-topped plateaus and sinuous ridges are morphologies that are analogous to those observed on the coastal plain of Hawai'i, where lava

A review of two methods used in the USA to assess HE during fluoroscopic-based radiology

International Nuclear Information System (INIS)

Craig Yoder, R.; Salasky, Mark R.

2016-01-01

Dosemeter results for ∼81 500 people performing fluoroscopic and interventional radiology procedures were examined to identify differences between groups monitored either by using two dosemeters, one placed at the collar above the apron and a second placed under the apron on the torso (EDE1) or by using one single dosemeter placed at the collar above the apron (EDE2). The median annual HE was 0.17 mSv for those monitored using the EDE1 protocol and 0.26 mSv for the group using the EDE2 protocol. The EDE2 method was used most frequently with the EDE1 method preferred for those more highly exposed. Approximately, 22 % of dosemeter results for EDE1 were inconsistent with expected norms based on over and under apron dosemeter relationships. (authors)

Coastal structural remains on the east coast of India: Evidence of maritime activities and their significance

Digital Repository Service at National Institute of Oceanography (India)

Tripati, S.

, Masulipatnam and Nagapattanam. On the other hand, Dronimukha refers to a port situated near the confluence of the river and the sea. Dronimukha was also a market place. Interestingly, the ports such as Dwarka, Tondi and Puhar also had the same meaning... and these port towns had well-established markets and hinterland connections (Roy 1994). Besides the geographical considerations in the location of ports, the maritime structures such as boatbuilding yards, landing places, boat shelters, causeways, wharves...

Constraints on the formation and properties of a Martian lobate debris apron: Insights from high-resolution topography, SHARAD radar data, and a numerical ice flow model

Science.gov (United States)

Parsons, Reid; Holt, John

2016-03-01

Lobate debris aprons (LDAs) are midlatitude deposits of debris-covered ice formed during one or more periods of glaciation during the Amazonian period. However, little is known about the climate conditions that led to LDA formation. We explore a hypothesis in which a single, extended period of precipitation of ice on the steep slopes of Euripus Mons (45°S, 105°E—east of the Hellas Basin) produced a flowing ice deposit which was protected from subsequent ablation to produce the LDA found at this location. We test this hypothesis with a numerical ice flow model using an ice rheology based on low-temperature ice deformation experiments. The model simulates ice accumulation and flow for the northern and southern lobes of the Euripus Mons LDA using basal topography constrained by data from the Shallow Radar (SHARAD) and a range of ice viscosities (determined by ice temperature and ice grain size). Simulations for the northern lobe of the Euripus LDA produce good fits to the surface topography. Assuming an LDA age of ˜60 Myr and an expected temperature range of 200 to 204 K (for various obliquities) gives an ice grain size of ≈2 mm. Simulations of the southern section produce poor fits to surface topography and result in much faster flow timescales unless multiple ice deposition events or higher ice viscosities are considered.

Site Assessment Report/Corrective Action Plan Fuel Hydrant System (Site SS-41) Project DKFX937081R1, Charleston Air Force Base, South Carolina

National Research Council Canada - National Science Library

1996-01-01

... #4 and the aircraft apron. Limited investigations were performed on those portions of the fuel hydrant system located on the west side of the drainage ditch due to ongoing Navy fuel hydrant system and aircraft apron renovation projects...

The practical application of ICRP recommendations regarding dose-equivalent limits for workers to staff in diagnostic X-ray departments

International Nuclear Information System (INIS)

Gill, J.R.; Beaver, P.F.; Dennis, J.A.

1980-01-01

Members of hospital staff who work in the X-ray room with patients, wear lead aprons to protect their bodies. These aprons greatly reduce the radiation dose rate at the surface of the body underneath the apron, but do not give any protection to parts of the body not covered by the apron, especially the head, neck, arms and legs. The ICRP's system of dose limitation for non-uniform irradiation of the body has been applied to exposure of this kind and a simple formula has been derived that permits the calculation of a good approximation to the effective dose-equivalent, using two dosemeters. One dosemeter is worn at chest or waist level under the apron to monitor the dose-equivalent received by protected organs while the other is worn on the collar or forehead to monitor the head and neck. Evidence based on published data is presented that suggests that in work of this nature, contrary to earlier opinion, the limiting factor is the dose equivalent received by the organs of the head and neck. The implications of this conclusion for routine personal monitoring are discussed. (H.K.)

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

International Nuclear Information System (INIS)

Chang, Rong-Chou; Yu, Cheng-Ching; Hsu, Fang-Yuh; Chen, Tou-Rong; Hsu, Shih-Ming; Tyan, Yeu-Sheng

2011-01-01

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 (H p (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.

Constraints on Lobate Debris Apron Evolution and Rheology from Numerical Modeling of Ice Flow

Science.gov (United States)

Parsons, R.; Nimmo, F.

2010-12-01

Recent radar observations of mid-latitude lobate debris aprons (LDAs) have confirmed the presence of ice within these deposits. Radar observations in Deuteronilus Mensae have constrained the concentration of dust found within the ice deposits to <30% by volume based on the strength of the returned signal. In addition to constraining the dust fraction, these radar observations can measure the ice thickness - providing an opportunity to more accurately estimate the flow behavior of ice responsible for the formation of LDAs. In order to further constrain the age and rheology of LDA ice, we developed a numerical model simulating ice flow under Martian conditions using results from ice deformation experiments, theory of ice grain growth based on terrestrial ice cores, and observational constraints from radar profiles and laser altimetry. This finite difference model calculates the LDA profile shape as it flows over time assuming no basal slip. In our model, the ice rheology is determined by the concentration of dust which influences the ice grain size by pinning the ice grain boundaries and halting ice grain growth. By varying the dust fraction (and therefore the ice grain size), the ice temperature, the subsurface slope, and the initial ice volume we are able to determine the combination of parameters that best reproduce the observed LDA lengths and thicknesses over a period of time comparable to crater age dates of LDA surfaces (90 - 300 My, see figure). Based on simulations using different combinations of ice temperature, ice grain size, and basal slope, we find that an ice temperature of 205 K, a dust volume fraction of 0.5% (resulting in an ice grain size of 5 mm), and a flat subsurface slope give reasonable model LDA ages for many LDAs in the northern mid-latitudes of Mars. However, we find that there is no single combination of dust fraction, temperature, and subsurface slope which can give realistic ages for all LDAs suggesting that all or some of these

78 FR 57211 - Notice of Passenger Facility Charge (PFC) Approvals and Disapprovals

Science.gov (United States)

2013-09-17

... removal equipment. Emergency radio system upgrade. PFC administrative fees. Decision Date: November 1... Use: Taxiway A pavement analysis and soil test. Taxiway A pavement rehabilitation. Runway 17/35 rehabilitation design. Taxiway/apron/fuel road pavement replacement. Taxiway/apron/fuel road pavement replacement...

The estimation of occupational effective dose in diagnostic radiology with two dosimeters

International Nuclear Information System (INIS)

Niklason, L.T.; Marx, M.V.; Chan, Heang-Ping

1994-01-01

Annual effective dose limits have been proposed by national and international radiation protection committees. Radiation protection agencies must decide upon a method of converting the radiation dose measured from dosimeters to an estimate of effective dose. A proposed method for the estimation of effective dose from the radiation dose to two dosimeters is presented. Correction factors are applied to an over-apron collar dose and an under-apron dose to estimate the effective dose. Correction factors are suggested for two cases, both with and without a thyroid shield. Effective dose may be estimated by the under-apron dose plus 6% of the over-collar dose if a thyroid shield is not worn or plus 2% of the over-collar dose if a thyroid shield is worn. This method provides a reasonable estimate of effective dose that is independent of lead apron thickness and accounts for the use of a thyroid shield. 17 refs., 3 tabs

Radiation dose in vertebroplasty

International Nuclear Information System (INIS)

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.

2004-01-01

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.)

Are the different gully morphologies due to different formation processes on the Kaiser dune field on Mars?

Science.gov (United States)

Pasquon, K.; Gargani, J.; Nachon, M.; Conway, S. J.; Massé, M.; Jouannic, G.; Balme, M. R.; Costard, F.; Vincendon, M.

2017-12-01

Diverse gully morphologies are seen on Mars and differences are often neglected for simplification. Here we describe in detail the morphology and present-day activity of two gully-systems on the Kaiser dune field in the southern hemisphere of Mars. We then compare their activity with that of the morphologically distinct linear dune gullies present on the same dunes. The studied gully-systems have large depositional aprons (named "large apron gullies") and occur on dune faces oriented westward. They are active from mid-autumn to late winter (i.e. from Ls 50° to Ls 180°) coinciding with CO2 ice condensation/sublimation cycles. Sandy material collapses from the alcove flanks onto the alcove floor sporadically throughout this period. This accumulated sand is remobilized by punctuated mass flows which we estimate to be up to 7100 m3 in volume. These flows run out on to the apron and occur between Ls 120° and Ls 160°. These mass flow events occur when the number of "digitate flows" is at its seasonal maximum. Digitate flows are characterized by long-narrow zig-zagging low-albedo tracks and do not seem to transport appreciable sediment, and they can number in the hundreds. Small pits appear at their termini or midway along and sometimes these pits are re-deepened by subsequent flows. These events repeat every year and using volume balance calculations we find that the whole system could be built on a timescale of hundreds of martian ears. These large apron gullies differ in morphology and timing from the linear dune gullies. The linear dune gullies are active in late winter, or beginning of spring when the CO2 frost finally sublimates, which occurs after the activity of the large apron gullies. Due to the difference of orientation between large apron gullies and linear dune as well as timing, we infer that insolation, which may influence (i) the depth to ground ice, (ii) the amount of volatiles deposits, is the main cause their differences. Sediment transport by CO2

Experimental study of 2D scour and its protection at a rubble-mound breakwater

DEFF Research Database (Denmark)

Sumer, B. Mutlu; Fredsøe, Jørgen

2000-01-01

investigated for the following cases: (1) the protection apron with one layer of stones and (2) that with several layers of stones. The mechanism of slumping down of stones of the protection apron was also considered. The results of the toe protection study are given in the form of diagrams....

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

International Nuclear Information System (INIS)

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

2015-01-01

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. (authors)

Monte Carlo simulations of personal exposure in diagnostic radiology and representative part of the body

International Nuclear Information System (INIS)

Ragan, P.; Fueloep, M.

2008-01-01

The basic requirements for a representative part of the body for placing a personal dosimeter are to provide a reliable approximation of an effective dose for almost all practical situations, independent of type, energy and incident angle of radiation and with prescribed overall accuracy. For quite a lot of situations it is a problem to find such a place, e. g. using a lead apron is a situation where it is important to make a correct decision for placing the personal dosimeter. For the dosimeter on the apron the dose is highly overestimated and the measured dose under the apron underestimates the estimate of the effective dose. To solve the problem can help Monte Carlo simulations using a mathematical phantom of a human body with and without lead apron. Doses in organs and tissues as results of MC simulations are used to determine a fraction of the effective dose for unshielded parts of the body (hands, legs, head, etc. ) in comparison with simulations without the apron. The mathematical phantom of the human body was used for the simulation of a patient and a physician in a geometry, where the physician is at a thigh of the patient and a scattered radiation is impinging obliquely from the front to the left hand of the body of physician. (authors)

Protection of persons undergoing radiological examinations ...

African Journals Online (AJOL)

Protection was in the form of gonad shields, lead apron to shield the unwanted parts during examinations and coning the X-ray field before exposure. The staff had Thermoluminscent Dosimeters (TLD) to monitor dose levels received by such staff every three months. They wore hand gloves, lead aprons and stayed behind ...

The effect of patient shield position on gonad dose during lumbar spine radiography

International Nuclear Information System (INIS)

Clancy, Conor L.; O'Reilly, Geraldine; Brennan, Patrick C.; McEntee, Mark F.

2010-01-01

Background: In an effort to standardise radiological practices in the Republic of Ireland, current legislation states that 'written protocols for every type of standard radiological practice shall be established'. In order to fulfil this requirement the Irish Medical Council recommends the protocols issued by the Commission of European Communitees (CEC) for adoption in the country. Whilst this document does provide good guidance with regard to various radiographic factors, patient shielding instructions are notably ambiguous. The aim of this study was to remove some of this ambiguity by defining the optimal method of positioning patient shielding in antero-posterior (AP) and lateral lumbar spine radiographic examinations. These projections were chosen on the basis of their area of coverage being in close to and in some cases including the reproductive organs. They also represent the highest source of collective population dose of any conventional radiographic examination carried out in the UK. Method: A dosimetry study was devised to establish organ dose to the male testes and female ovaries using various clinically advocated methodologies for positioning patient shielding these included: no apron; tube-side apron; receptor-side apron and a wrap-around apron. The study was carried out using a direct digital radiography unit, an anthropomorphic phantom, various lead aprons and lithium thermoluminescent dosimeters (TLD). Results: For the AP projection, a statistically significant testes dose reduction of 42% (p ≤ 0.01) was observed when a tube-sided apron was used. No testes dose reductions were noted for the lateral projection. Ovary dose savings were not observed for any of the shielding methods investigated. Conclusion: This study found that the testes dose in AP examinations was reduced by 42% when patient shielding was positioned inferior to the imaged field and on the tube-side of the patient. This result validates the shielding methods used at the majority

Use and effect of X-ray protective clothing

International Nuclear Information System (INIS)

Rothe, W.

1976-01-01

The use of X-ray protective clothing in direct handling the patient was studied in 76 X-ray departments. Mainly two types of lead rubber aprons are used, older ones with a lead equivalent of 0.2 mm and aprons according to TGL 200-1606 with a lead equivalent of 0.25 mm. Aprons are not yet worn in all surgical departments. Their replacement by protective skirts is to be refused. If at all, lead rubber gloves are only used in standardized fluoroscopic examinations, especially in examining the gastrointestinal tract. It is emphasized that only the protected fore-part is to be directed to the main radiation source, especially in seating or leaning forward positions. (author)

Ranging Behaviour of Commercial Free-Range Laying Hens.

Science.gov (United States)

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

2016-04-26

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

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. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evaluation of radiation protection in interventional orthopedic procedures in Khartoum state

International Nuclear Information System (INIS)

Ibrahim, M. Y. A.

2013-06-01

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)

Floating barrier

Energy Technology Data Exchange (ETDEWEB)

1968-05-06

This floating barrier consists of relatively long elements which can be connected to form a practically continuous assembly. Each element consists of an inflatable tube with an apron of certain height, made of impregnated fabric which is resistant to ocean water and also to hydrocarbons. Means for connecting one element to the following one, and means for attaching ballast to the apron are also provided.

The effect of patient shield position on gonad dose during lumbar spine radiography

Energy Technology Data Exchange (ETDEWEB)

Clancy, Conor L.; O' Reilly, Geraldine [Department of Medical Physics and Bioengineering, Garden Hill House, St. James Hospital, James Street, Dublin (Ireland); Brennan, Patrick C. [Discipline of Medical Radiation Sciences, C42 - Cumberland Campus, The University of Sydney, Lidcombe NSW 2141 (Australia); McEntee, Mark F. [School of Medicine and Medical Science, Health Sciences Centre, University College Dublin, Belfield, Dublin 4 (Ireland)], E-mail: mark.mcentee@ucd.ie

2010-05-15

Background: In an effort to standardise radiological practices in the Republic of Ireland, current legislation states that 'written protocols for every type of standard radiological practice shall be established'. In order to fulfil this requirement the Irish Medical Council recommends the protocols issued by the Commission of European Communitees (CEC) for adoption in the country. Whilst this document does provide good guidance with regard to various radiographic factors, patient shielding instructions are notably ambiguous. The aim of this study was to remove some of this ambiguity by defining the optimal method of positioning patient shielding in antero-posterior (AP) and lateral lumbar spine radiographic examinations. These projections were chosen on the basis of their area of coverage being in close to and in some cases including the reproductive organs. They also represent the highest source of collective population dose of any conventional radiographic examination carried out in the UK. Method: A dosimetry study was devised to establish organ dose to the male testes and female ovaries using various clinically advocated methodologies for positioning patient shielding these included: no apron; tube-side apron; receptor-side apron and a wrap-around apron. The study was carried out using a direct digital radiography unit, an anthropomorphic phantom, various lead aprons and lithium thermoluminescent dosimeters (TLD). Results: For the AP projection, a statistically significant testes dose reduction of 42% (p {<=} 0.01) was observed when a tube-sided apron was used. No testes dose reductions were noted for the lateral projection. Ovary dose savings were not observed for any of the shielding methods investigated. Conclusion: This study found that the testes dose in AP examinations was reduced by 42% when patient shielding was positioned inferior to the imaged field and on the tube-side of the patient. This result validates the shielding methods used at the

Ranging Behaviour of Commercial Free-Range Laying Hens

Directory of Open Access Journals (Sweden)

Leonard Ikenna Chielo

2016-04-01

Full Text Available 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

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

International Nuclear Information System (INIS)

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

2016-01-01

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. (paper)

Radiation exposure of operator during various interventional procedures

International Nuclear Information System (INIS)

Yu, In Kyu; Chung, Jin Wook; Han, Joon Koo; Park, Jae Hyung; Kang, Wee Saing

1994-01-01

To investigate the levels of radiation exposure of an operator which may be influenced by the wearing an apron, type of procedure, duration of fluoroscopy and operator's skill during various interventional procedures. Radiation doses were measured both inside and outside the apron(0.5 mm lead equivalent) of the operator by a film badge monitoring method and the duration of fluoroscopy was measured in 96 procedures prospectively. The procedures were 30 transcatheter arterial embolization (TAE), 25 percutaneous transhepatic biliary drainages (PTBD), 16 stone removals (SR), 15 percutaneous needle aspirations (PNCA) and 10 percutaneous nephrostomies(PCN). To assess the difference of exposure by the operator's skill, the procedures of TAE and PTBD were done separately by groups of staffs and residents. Average protective effect of the apron was 72.8%. Average radiation exposure(unit: μ Sv/procedure was 23.3 in PTBD by residents, 10.0 in PTBD by staffs, 10.0 in SR, 8.7 in TAE by residents, 7.3 in TAE by staffs, 9.0 in PCN and 6.0 in PCNA. Average radiation exposure of residents were 1.9 times greater than those of staffs. Radiation exposure was not proportionally related to the duration of fluoroscopy, but influenced by wearing an apron, various types of procedure and operator's skills

Radiation dose measurement for patients and staff during cardiac catheterization

International Nuclear Information System (INIS)

Joda, H. H. M.

2009-07-01

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)

Patient exposures from intra-oral dental radiographic examinations

International Nuclear Information System (INIS)

Acram, S.Y.

1987-01-01

This report describes a study to determine patient exposure to selected areas at the thyroid gland, the central chest area, the testes and ovaries, from conventional radiographic procedures for dental patients. The study was designed also to compare the efficiency of the cervical lead shield with the lead apron which both serve as protection from radiation. The exposure levels for all radiographic procedures are as follows. The dose received by the thyroid gland area with a lead apron is approximately 300 mR and without the lead apron 350 mR. The dose received by the thyroid gland area with the use of a cervical lead shield was decreased to 30 - 35 mR for a single X-ray. The cervical lead shield reduced the radiation dose as much as 90% in the thyroid region. The thyroid gland is of great importance for radiation protection in dental radiography because of the possible relationship between thyroid cancer and radiation. The radiation dose for the molar and pre-molar area in a series of status X-rays is 1800 - 2600 mR. The dose which reaches the chest area with or without a lead apron or cervical lead shield, is 50 mR. 14 refs.; 1 figure

Radiation protection clothing in X-ray diagnostics. Comparison of attenuation equivalents in narrow beam and inverse broad-beam geometry

International Nuclear Information System (INIS)

Pichler, Thomas; Schoepf, T.; Ennemoser, O.

2011-01-01

Purpose: Standard DIN EN 61 331-1 for attenuation measurements in the narrow and broad beam as well as DIN 6857-1 for the determination of shielding properties in the inverse broad-beam geometry are available for testing the attenuation of protection clothing. The attenuation measurements in the narrow beam don't consider scattered radiation and fluorescence due to the arrangement. This leads to the fact that the protective effect of lead-free materials will be misestimated when compared to lead. Therefore, the differences in attenuation equivalents, determined by both test methods for topical radiation protection aprons, were examined. Materials and Methods: The attenuations in inverse broad-beam geometry according to DIN 6857-1 and in the narrow beam according to DIN EN 61 331-1 were measured using commercially available aprons. They were made of lead, lead-reduced and lead-free materials. For determination of the attenuation equivalents, certificated lead-foils with high purity and a precise thickness of 0.1 to 1.25 mm were used. Results: The measurements in the narrow beam according to DIN EN 61 331-1 showed that nearly all aprons reach the required lead equivalent at mid-range tube voltages of 100 kV. At higher and lower tube voltages, the requirements of DIN EN 61 331-3 were largely not met. In contrast, the testing of the same aprons in inverse broad-beam geometry according to DIN 6857-1 showed that only a few aprons meet the requirements for being classified in the nominal protection class. Conclusion: The measurements suggest that testing method DIN 6857-1 has yet to prevail and that manufacturers are just beginning to develop the appropriate protective materials. (orig.)

SU-F-I-71: Fetal Protection During Fluoroscopy: To Shield Or Not to Shield?

International Nuclear Information System (INIS)

Joshi, S; Vanderhoek, M

2016-01-01

Purpose: Lead aprons are routinely used to shield the fetus from radiation during fluoroscopically guided interventions (FGI) involving pregnant patients. When placed in the primary beam, lead aprons often reduce image quality and increase fluoroscopic radiation output, which can adversely affect fetal dose. The purpose of this work is to identify an effective and practical method to reduce fetal dose without affecting image quality. Methods: A pregnant patient equivalent abdominal phantom is set on the table along with an image quality test object (CIRS model 903) representing patient anatomy of interest. An ion chamber is positioned at the x-ray beam entrance to the phantom, which is used to estimate the relative fetal dose. For three protective methods, image quality and fetal dose measurements are compared to baseline (no protection):1. Lead apron shielding the entire abdomen; 2. Lead apron shielding part of the abdomen, including the fetus; 3. Narrow collimation such that fetus is excluded from the primary beam. Results: With lead shielding the entire abdomen, the dose is reduced by 80% relative to baseline along with a drastic deterioration of image quality. With lead shielding only the fetus, the dose is reduced by 65% along with complete preservation of image quality, since the image quality test object is not shielded. However, narrow collimation results in 90% dose reduction and a slight improvement of image quality relative to baseline. Conclusion: The use of narrow collimation to protect the fetus during FGI is a simple and highly effective method that simultaneously reduces fetal dose and maintains sufficient image quality. Lead aprons are not as effective at fetal dose reduction, and if placed improperly, they can severely degrade image quality. Future work aims to investigate a wider variety of fluoroscopy systems to confirm these results across many different system geometries.

Eye lens dose correlations with personal dose equivalent and patient exposure in paediatric interventional cardiology performed with a fluoroscopic biplane system.

Science.gov (United States)

Alejo, L; Koren, C; Corredoira, E; Sánchez, F; Bayón, J; Serrada, A; Guibelalde, E

2017-04-01

To analyse the correlations between the eye lens dose estimates performed with dosimeters placed next to the eyes of paediatric interventional cardiologists working with a biplane system, the personal dose equivalent measured on the thorax and the patient dose. The eye lens dose was estimated in terms of H p (0.07) on a monthly basis, placing optically stimulated luminescence dosimeters (OSLDs) on goggles. The H p (0.07) personal dose equivalent was measured over aprons with whole-body OSLDs. Data on patient dose as recorded by the kerma-area product (P KA ) were collected using an automatic dose management system. The 2 paediatric cardiologists working in the facility were involved in the study, and 222 interventions in a 1-year period were evaluated. The ceiling-suspended screen was often disregarded during interventions. The annual eye lens doses estimated on goggles were 4.13±0.93 and 4.98±1.28mSv. Over the aprons, the doses obtained were 10.83±0.99 and 11.97±1.44mSv. The correlation between the goggles and the apron dose was R 2 =0.89, with a ratio of 0.38. The correlation with the patient dose was R 2 =0.40, with a ratio of 1.79μSvGy -1 cm -2 . The dose per procedure obtained over the aprons was 102±16μSv, and on goggles 40±9μSv. The eye lens dose normalized to P KA was 2.21±0.58μSvGy -1 cm -2 . Measurements of personal dose equivalent over the paediatric cardiologist's apron are useful to estimate eye lens dose levels if no radiation protection devices are typically used. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

SU-F-I-71: Fetal Protection During Fluoroscopy: To Shield Or Not to Shield?

Energy Technology Data Exchange (ETDEWEB)

Joshi, S; Vanderhoek, M [Henry Ford Health System, Detroit, MI (United States)

2016-06-15

Purpose: Lead aprons are routinely used to shield the fetus from radiation during fluoroscopically guided interventions (FGI) involving pregnant patients. When placed in the primary beam, lead aprons often reduce image quality and increase fluoroscopic radiation output, which can adversely affect fetal dose. The purpose of this work is to identify an effective and practical method to reduce fetal dose without affecting image quality. Methods: A pregnant patient equivalent abdominal phantom is set on the table along with an image quality test object (CIRS model 903) representing patient anatomy of interest. An ion chamber is positioned at the x-ray beam entrance to the phantom, which is used to estimate the relative fetal dose. For three protective methods, image quality and fetal dose measurements are compared to baseline (no protection):1. Lead apron shielding the entire abdomen; 2. Lead apron shielding part of the abdomen, including the fetus; 3. Narrow collimation such that fetus is excluded from the primary beam. Results: With lead shielding the entire abdomen, the dose is reduced by 80% relative to baseline along with a drastic deterioration of image quality. With lead shielding only the fetus, the dose is reduced by 65% along with complete preservation of image quality, since the image quality test object is not shielded. However, narrow collimation results in 90% dose reduction and a slight improvement of image quality relative to baseline. Conclusion: The use of narrow collimation to protect the fetus during FGI is a simple and highly effective method that simultaneously reduces fetal dose and maintains sufficient image quality. Lead aprons are not as effective at fetal dose reduction, and if placed improperly, they can severely degrade image quality. Future work aims to investigate a wider variety of fluoroscopy systems to confirm these results across many different system geometries.

Repercussions of embarkation wharves in Lakshadweep Islands on coral communities and their ecology

Digital Repository Service at National Institute of Oceanography (India)

Ravindran, J.; Manikandan, B.; Venkatesh, M.; ManiMurali, R.; Marimuthu, N.; Wafar, M.V.M.

diversity of corals dominated by the massive reef-building corals was lost, affecting the structure and stability of the reef at these sites Resilience potential of the reef became poor due to the monospecific colonization of corals belonging to very few...

PERENCANAAN SAND POCKET SEBAGAI BANGUNAN PENGENDALI ALIRAN SEDIMEN DI KALI OPAK YOGYAKARTA

Directory of Open Access Journals (Sweden)

Yeri Sutopo

2016-07-01

Full Text Available This research conducted in Opak River, in Yogyakarta. This river has broad (river flow area 27,04 km2, and 20,11 km in length. The research objective is to make a planning about effective rainfall in 50 years and found the Opak Sand Pocket design. This research used methods with direct-survey in location, and collected secondary data from related agencies. From the data, it was obtained the value of precipitation the design, discharge flood design, dimensions of building hydrolic design (Main Dam, Sub Dam, Apron, and analysis the effectiveness of sand pocket in reducing the sediment that has happened. Based on the results of the research, discharge maximum ( Q50 that occurs in the river of 202,77 m3/s. So it can be calculated that sand pocket designed will have wide of apron 54,04 m, with total high of Main Dam 6 m, total high of Sub Dam 6 m, length of apron 10 m, thick of apron 0,96 m. Based on the ability of sand pocket in reducing the rate of the sediment that is happened, the building has effectiveness until 90,20 % in reducing bed load based on the calculation. Therefore, it can be argued that the building has been effective to reduce the speed of sediment occurring in Opak River.

Effective dose to staff from interventional procedures: Estimations from single and double dosimetry

International Nuclear Information System (INIS)

Kuipers, G.; Velders, X. L.

2009-01-01

The exposure of 11 physicians performing interventional procedures was measured by means of two personal dosemeters. One personal dosemeter was worn outside the lead apron and an additional under the lead apron. The study was set up in order to determine the added value of a dosemeter worn under the lead apron. With the doses measured, the effective doses of the physicians were estimated using an algorithm for single dosimetry and two algorithms for double dosimetry. The effective doses calculated with the single dosimetry algorithm ranged from 0.11 to 0.85 mSv in 4 weeks. With the double dosimetry algorithms, the effective doses ranged from 0.02 mSv to 0.47 mSv. The statistical analysis revealed no significant differences in the accuracy of the effective doses calculated with single or double dosimetry algorithms. It was concluded that the effective dose cannot be considered a more accurate estimate when two dosemeters are used instead of one. (authors)

Ampliación del puerto de Miami, (U.S.A.

Directory of Open Access Journals (Sweden)

Volkert, David

1966-11-01

Full Text Available As there was no available space in the zones surrounding the existing harbour, and the bay had a number of islands, which could be easily connected with fill soil, it was decided to form a harbour taking advantage of these islands. The planform of the new harbour is rectangular, and the perimeter walls have been used as wharves. As this fill soil is separated from the coastline, a bridge from the mainland has been built, carrying both motor vehicles and rail traffic. In view of the considerable length of the bridge, and the need to ensure navigation along the coastline, the central part of the bridge, over the navigation canal, has an elevating span. To obtain sufficient depth of water by the wharves, considerable amount of dredging has been necessary, as well as sheet piling.Como no se disponía de espacio en las zonas adyacentes al puerto en explotación, y la bahía tenía una serie de Islotes propicios para hacer un relleno, surgió la idea de realizarlo, en tomo a aquéllos, con planta rectangular, aprovechando los muros perimetrales para formar los muelles de atraque. Por hallarse este relleno separado de la costa, se ha construido un paso superior, sobre el agua, para el tráfico de vehículos de ruedas neumáticas, y una plataforma paralela destinada al tráfico ferroviario. Dada la gran longitud del paso y la necesidad de asegurar la navegación costera, la parte central del paso, correspondiente al canal, se salva con un tramo basculante. Para conseguir aguas profundas en los muelles se han realizado importantes operaciones de dragado e hinca de tablestacas.

Optimisation of staff protection

International Nuclear Information System (INIS)

Faulkner, K.; Marshall, N.W.; Rawlings, D.J.

1997-01-01

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)

Radiation exposures received by the staff in the interventional radiology unit

International Nuclear Information System (INIS)

Vekic, Branko; Miljanic, S.; Ban, R.; Ranogajec-Komor, M.; Stern-Padovan, R.; Basic, B.

2008-01-01

Full text: As a consequence of the highly nonuniform exposure conditions in the interventional radiology, a reliable estimation of the effective dose for occupationally exposed persons requires a number of dose measurements at various locations of the body. The nonuniform occupational exposure is mainly associated with the relatively short distance to the radiation source (the scattered radiation from the patient) and the attenuation of the scattered radiation by protective clothing and shielding. The staff who undertake these procedures may receive radiation doses approaching the dose limits suggested by International Commission on Radiological Protection (ICRP 1991) if there is a high patient workload, for extended period of time. According to the Croatian radiation protection regulations for the effective dose estimation it is mandatory to use one dosimeter placed at the left side of the chest under the protective apron. From the dosimeter reading (dosimeter is calibrated in term of H p (10)) the effective dose is estimated. If additional dosimeters are worn on different parts of the body, their results have to be recorded, but they are not used for effective dose estimations. In the University Hospital Zagreb the personnel performing interventional radiology procedures in addition to the dosimeter placed under the apron always wear another dosimeter placed on the apron at the neck or shoulder position. In this work, the results of recorded dosimetry measurements performed during the period of 10 years were analysed. Special attention was given to the evaluation of the effective dose. The results of only one dosimeter are compared with the results obtained with two dosimeters. In the later case the effective dose was evaluated using some proposed algorithms for double dosimetry. Since it is well known that the evaluation of effective dose from the reading (without any correction) of only one dosimeter placed under the apron usually underestimate the effective

Exposure dose to gonad and its reduction in CT examinations

International Nuclear Information System (INIS)

Suzuki, Shoichi; Menju, Mina; Nakazawa, Masato

2006-01-01

Exposure doses to gonad (ovary and uterus) due to scattering at the ordinary CT examinations of head, breast, and abdomen (liver) were measured and their reductions by the protective apron usually used in clinic were evaluated by comparison of the given and International Commission of Radiological Protection (ICRP) data for risk assessment. Multi-slice helical/scanno-helical CT for the regions under ordinary diagnostic conditions was done by the apparatus Toshiba Aquilion 16 for the human body phantom (Alderson) with or without the apron (Hagoromo) equivalent to 0.25 mm thick lead. Doses inside and outside the beam flux were measured by the thermoluminescent dosimeter, of which data were corrected by Radcal Model 300 ionization chamber. The doses in the gonad due to scattering were found to be in the range from 0.01 (head CT) to 1 (liver CT) mGy and to be reduced in 20-30% by the apron. Found dose were far smaller than the ICRP threshold values for inducing teratosis and infertality. (T.I.)

Overview of double dosimetry procedures for the determination of the effective dose to the interventional radiology staff

International Nuclear Information System (INIS)

Jaervinen, H.; Buls, N.; Clerinx, P.; Jansen, J.; Miljanic, S.; Nikodemova, D.; Ranogajec-Komor, M.; D'Errico, F.

2008-01-01

In interventional radiology, for an accurate determination of effective dose to the staff, measurements with two dosemeters have been recommended, one located above and one under the protective apron. Such 'double dosimetry' practices and the algorithms used for the determination of effective dose were reviewed in this study by circulating a questionnaire and by an extensive literature search. The results indicated that regulations for double dosimetry almost do not exist and there is no firm consensus on the most suitable calculation algorithms. The calculation of effective dose is mainly based on the single dosemeter measurements, in which either personal dose equivalent, directly, (dosemeter below the apron) or a fraction of personal dose equivalent (dosemeter above the apron) is taken as an assessment of effective dose. The most recent studies suggest that there might not be just one double dosimetry algorithm that would be optimum for all interventional radiology procedures. Further investigations in several critical configurations of interventional radiology procedures are needed to assess the suitability of the proposed algorithms. (authors)

Optimum Drafting Conditions Of Polyester And Viscose Blend Yarns

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Hatamvand Mohammad

2017-09-01

Full Text Available In this study, we used an experimental design to investigate the influence of the total draft, break draft, distance between the aprons (Clips and production roller pressure on yarn quality in order to obtain optimum drafting conditions for polyester and viscose (PES/CV blend yarns in ring spinning frame. We used PES fibers (1.4 dtex × 38 mm long and CV fibers (1.6 dtex × 38 mm long to spin a 20 Tex blend yarn of PES (70%/CV (30% blend ratio. When the break draft, adjustment of distance between of aprons and roller pressure is not reasonable, controlling and leading of the fibers is not sufficient for proper orientation of the fibers in the yarn structure to produce a high quality yarn. Experimental results and statistical analysis show that the best yarn quality will be obtained under drafting conditions total draft of 38, 1.2 break draft, 2.8 mm distance between of aprons and maximum pressure of the production top roller (18daN.

Is extremity monitoring recommended for interventional cardiologists?

International Nuclear Information System (INIS)

Lima, Ana Luiza S.; Rodrigues, Barbara Beatriz D.; Mauricio, Claudia L.P.; Canevaro, Lucia V.

2009-01-01

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)

Radiation protection during hybrid procedures: innovation creates new challenges.

Science.gov (United States)

Sawdy, Jaclynn M; Gocha, Mark D; Olshove, Vincent; Chisolm, Joanne L; Hill, Sharon L; Phillips, Alistair; Galantowicz, Mark; Cheatham, John P; Holzer, Ralf J

2009-09-01

The cooperation between interventional cardiologists and cardiothoracic surgeons has expanded the spectrum of treatment modalities for patients with congenital heart disease. These hybrid techniques have created new challenges, one of which being the provision of adequate but practical radiation protection. This study evaluates the use of a lightweight radiation protection drape (RADPAD) that may be suitable for shielding during hybrid procedures. To simulate a pediatric patient, an 8.7 liter water-filled tub was placed on an X-ray table and exposed to 10-second cine acquisition runs. Radiation exposure was measured at twelve specified locations around the table using a model with three different levels of radiation protection: no shielding, shielding using a traditional 0.35 mm lead-equivalent apron, and shielding using the 0.25 mm lead-equivalent RADPAD. The traditional lead apron and the RADPAD significantly reduced the amount of radiation dose when compared with no shielding. The standard lead apron provided slightly greater radiation protection than the RADPAD (0.000064 radiation absorbed dose [rad] vs. 0.000091 rad; p = 0.012). The measured rad was significantly higher on the right side of the table, and the measured radiation dose decreased significantly with increasing distance from the table. The RADPAD has been shown to function as an efficient shielding device, even though it does not quite match the protection that can be expected from a standard lead apron. It complies with regulatory radiation protection requirements and its lightweight and sterile use make it particularly useful during hybrid procedures in the operating room.

Efficiency of the cervical lead shield during intraoral radiography

International Nuclear Information System (INIS)

Kaffe, I.; Littner, M.M.; Shlezinger, T.; Segal, P.

1986-01-01

The cervical lead shield was compared with the conventional lead apron with regard to efficiency of protection against radiation during a full-month survey (fourteen periapical and two bitewing radiographs). The study was performed on a Temex tissue-equivalent human phantom, and thermoluminescent dosimetry was used to measure radiation absorption in the ovaries, testes, and thyroid gland areas. Results showed that the cervical shield significantly reduces the amount of radiation to the skin in all three areas and is equally as effective as the combination of lead apron and thyroid shield. It is therefore recommended as a protective measure during intraoral radiography

Rusted Designs: The New Apron

OpenAIRE

Swindells, Steve; Burcikova, Mila

2013-01-01

Articulated as a practice of design-couture, conceptualized as a project that seeks a sense \\ud of social engagement through research, design and making of everyday ‘common couture’, \\ud Rusted puts craft action in a very close relation with daily (political) or practical life. Rusted \\ud designs collage pre-used fabric and clothing (found, bought or gifted) with new cloth, thus \\ud using items of fabric and clothing from different times, countries and with variety of social \\ud histories. Th...

Management of diagnostic x-ray radiation in developing countries

International Nuclear Information System (INIS)

Date, T.

2000-01-01

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

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.

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.

Dosimetry in Interventional Radiology - Effective Dose Estimation

International Nuclear Information System (INIS)

Miljanic, S.; Buls, N.; Clerinx, P.; Jarvinen, H.; Nikodemova, D.; Ranogajec-Komor, M; D'Errico, F.

2008-01-01

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 ( d ouble 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)

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.

Identification of irradiated crab using EPR

International Nuclear Information System (INIS)

Maghraby, A.

2007-01-01

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

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.

Location Planning for Dynamic Wireless Charging Systems for Electric Airport Passenger Buses

Directory of Open Access Journals (Sweden)

Stefan Helber

2018-01-01

Full Text Available The majority of the ground vehicles operating on the airside parts of commercial airports are currently powered by diesel engines. These include vehicles such as apron buses, fuel trucks, and aircraft tractors. Hence, these vehicles contribute to the overall CO 2 emissions of the aviation transport system and thus negatively influence its environmental footprint. To reduce this damaging environmental impact, these vehicles could potentially be electrified with on-board batteries as their energy sources. However, the conductive charging of such vehicles via stationary cable connections is rather time-consuming. A dynamic wireless charging system to supply public transportation passenger buses with electric energy while in motion has recently been installed on the Korea Advanced Institute of Science and Technology (KAIST campus and in the Korean city of Gumi. In this paper, we study configuration problems related to the use of this technology to make airport operations more environmentally sustainable. We concentrate on the power supply for apron buses and analyze the location planning problems related to the distribution of the required power supply and the wireless charging units in the apron road system. To this end, we develop a formal optimization model and discuss the first numerical results.

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)

Akahane, Keiichi; Tatsuzaki, Hideo; Iimoto, Takeshi; Ichiji, Takeshi; Hamada, Nobuyuki; Fujimichi, Yuki; Iwai, Satoshi; Ohguchi, Hiroyuki; Ohno, Kazuko; Yamauchi, Chiyo; Tsujimura, Norio; Hotta, Yutaka; Yamasaki, Tadashi; Yokoyama, Sumi

2014-01-01

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 H p (10) and H p (0.07), given by the dosemeter, is generally used as a surrogate of H p (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)

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

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Young

2011-02-15

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, H{sub p}(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

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

International Nuclear Information System (INIS)

Kim, Ji Young

2011-02-01

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, H p (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

Optimisation need of dental radiodiagnostic procedures: results of effective dose evaluation from Rando phantom measurements

International Nuclear Information System (INIS)

Borio, R.; Chiocchini, S.; Cicioni, R.; Degli Esposti, P.; Rongoni, A.; Sabatini, P.; Saetta, D.M.S.; Regi, L.; Caprino, G.

1994-01-01

Radiological examinations of different types are needed in dental practice both to make a correct diagnosis and to carry out an adequate therapy. Particularly in orthodentic practices, because of the youth of the majority of the patients, an assessment of the detriment to health (through the effective dose equivalent) caused by medical diagnostic exposure to ionising radiation is needed to make decisions about the optimisation of dental radiodiagnostic procedures. Experimental data from measurements on a Rando phantom were collected for the radiological examinations required for dental and for orthodontic practices (with and without protective apron and collar). The results show the effectiveness of the leaded apron and collar in all the examinations carried out, particularly in reducing thyroid dose. (author)

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)

Hudzietzova, J.; Sabol, J.; Fueloep, M.

2013-01-01

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)

Lower Monumental Spillway Hydraulic Model Study

National Research Council Canada - National Science Library

Wilhelms, Steven

2003-01-01

A 1:40 Froudian Scale model was used to investigate the hydraulic performance of the Lower Monumental Dam spillway, stilling basin, and tailrace for dissolved gas reduction and stilling basin apron scour...

75 FR 65551 - Notice of Passenger Facility Charge (PFC) Approvals and Disapprovals

Science.gov (United States)

2010-10-25

... lot and rehabilitate north public parking lot. Install high mast lighting for cargo apron. PFC program... that the portions of the proposed project related to the solar energy project were not eligible...

46 CFR 151.50-73 - Chemical protective clothing.

Science.gov (United States)

2010-10-01

... gloves. (3) Boots or shoe covers. (4) Coveralls or lab aprons. Note: “Guidelines for the Selection of... Industrial Hygienists, 1330 Kemper Meadow Drive, Cincinnati, OH 45240-1634, provides information on the...

X-ray protective clothing. Does DIN 6857-1 allow an objective comparison between lead-free and lead-composite materials?

International Nuclear Information System (INIS)

Eder, H.; Schlattl, H.; Hoeschen, C.

2010-01-01

Purpose: The validity of DIN 6857-1 to establish lead equivalence for protective clothing is evaluated by Monte Carlo simulations and measurements. Materials and Methods: Commercially available protective clothing made of lead, lead-free and lead-composite materials has been tested regarding its protective efficacy. The analysis has been performed on the one hand in accordance with the test conditions described in the manufacturing standard DIN EN 61331-3 and on the other hand following the new DIN 6857-1 standard. Additionally, measurements have been carried out under simulated patient conditions by using an Alderson-Rando phantom. Results: Following DIN EN 61331-3, the lead-free protective clothing achieved the required protective efficacy only at a restricted tube-voltage range. The test according to DIN 6857-1 showed that the protective criteria were fulfilled only by one lead-composite apron, but not by the three lead-free aprons examined. Thus, in order to guarantee the same protection as lead between 50 and 120 kV, the conditions of DIN 6857-1 must be fulfilled. Conclusion: A modification of DIN EN 61331-3 to account for secondary radiation is strongly advised in the case of lead-free materials. In summary, most of the protective lead-free aprons in use should be used with care, particularly for examinations with a high dose. (orig.)

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

International Nuclear Information System (INIS)

Vanhavere, F.

2007-01-01

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

Joint Rapid Airfield Construction (JRAC) 2007 Technology Demonstration

National Research Council Canada - National Science Library

Anderton, Gary L; Berney, IV, Ernest S; Mann, Travis A; Newman, J. K; Baylot, E. A; Miller, Daniel K; Mason, Quint

2008-01-01

...) unsurfaced runway and two 45,480-ft2 (4,225-m2) aircraft parking aprons with associated connector taxiways, all using JRAC technologies focused on rapid construction with reduced logistics and increased system reliability...

Study of noise inside the peshawar airport

International Nuclear Information System (INIS)

Khan, M.; Khan, A.R.; Shah, J.; Noor, S.; Aslam, T.

2007-01-01

The paper deals with the noise-study conducted at five different locations within the vicinity of International Airport, Peshawar (Pakistan). The sites selected for this study were Apron, Concourse Hall, Cargo Shed, Car Parking and Utility Block. Noise-levels were recorded during 'landing' and 'taking off' of aircrafts of six international, flights, operating from this Airport. The average noise levels at Apron, Concourse Hall, Cargo Shed, Car Parking and Utility Block were found to be in the range of 87.2-90.3, 77.7-82.0, 82.6-87.5, 0.1-84.5 and 85.0-85.8 dB (A) respectively. The results are discussed, with reference to permissible occupational noise-exposure limits. The health-impacts due to higher noise-level and their possible remedial measures have also been discussed. (author)

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 ...

Effectiveness and profitability of insecticide formulations used for ...

African Journals Online (AJOL)

ACSS

Apron, significantly lowered bean fly infestation by two to 60 fold when compared with control. .... and would only require validation of the results. ..... K., Ngamau, F.K. Ombwara and S.G.. Agonga (Eds.) ... Uganda: A cross-sectional study.

Routine monitoring of eye dose; and reply

Energy Technology Data Exchange (ETDEWEB)

Palmer, K; Jeans, S P; Faulkner, K; Bardsley, R A; Love, H G

1985-12-01

This letter briefly reports the assessment at Papworth Hospital of the feasibility of monitoring eye doses of staff using a film badge worn on the shoulder in addition to the badge worn under the lead apron. For three consecutive months hand and eye (forehead) dose were monitored using TLDs, while shoulder and body dose, recorded under the lead apron, were measured with film badges. For the four doctors monitored, (two radiologists and two cardiologists) the shoulder badge somewhat overestimated the eye dose. In the case of nurses, the dose recorded by the shoulder badge was of a similar order to the TLD-recorded eye dose. The reply from the Christie Hospital at Manchester comments on the use of the shoulder badge and contends that the use of forehead dosemeters to measure eye dose is to be preferred whenever possible.

Basement and climate controls on proximal depositional systems in continental settings

NARCIS (Netherlands)

Ventra, D.

2011-01-01

This doctoral dissertation discusses the sedimentology and dynamics of selected, modern and ancient clastic depositional systems (alluvial fans and colluvial aprons) at continental basin margins. The focus on single depositional systems gave the opportunity to devote particular attention to

Knowledge And Experience Of Work-Related Hazards And ...

African Journals Online (AJOL)

Tropical Journal of Health Sciences ... Health status of scavengers is therefore a public health concern, as they could be potential pathways for ... recorded for nose guard, face mask and overall/apron with 43.2%, 39.3% and 9.3% respectively.

Accomplishments under the Airport Improvement Program: Fiscal Year 1988

Science.gov (United States)

1988-01-01

WIND (PRIMARY) INDICATOR; SECURITY FENCING HOLBROOK 02 $22,766 CONDUCT MASTER PLAN UPDATE HOLBROOK MUNICIPAL (GENERAL AVIATION) KAYENTA 03 $1,238,484...CONSTRUCT RUNWAY, TAXIWAY, APRON AND KAYENTA ACCESS ROAD; INSTALL RUNWAY AND TAXIWAY (GENERAL AVIATION) LIGHTING SYSTEM, VISUAL APPROACH INDICATOR

Evaluation of the occupational doses of interventional radiologists

NARCIS (Netherlands)

Kuipers, Gerritjan; Velders, Xandra L.; de Winter, Robbert J.; Reekers, Jim A.; Piek, Jan J.

2008-01-01

The aim of the present study was to determine whether there is a linear relation between the doses measured above and those measured under the lead apron of the radiologists performing interventional procedures. To monitor radiation exposure the International Commission of Radiological Protection

9 CFR 416.2 - Establishment grounds and facilities.

Science.gov (United States)

2010-01-01

... AGRICULTURE REGULATORY REQUIREMENTS UNDER THE FEDERAL MEAT INSPECTION ACT AND THE POULTRY PRODUCTS INSPECTION... hand-washing areas, dressing and locker rooms, and toilets. (d) Ventilation. Ventilation adequate to... areas, livestock pens, trucks, poultry cages, picker aprons, picking room floors, and similar areas...

Accomplishments Under the Airport Improvement Program. Fiscal year 1987.

Science.gov (United States)

1987-01-01

PREPARATION); GRAND CANYON NATIONAL PARK ACQUIRE LAND FOR APPROACHES; INSTALL (PRIMARY) FENCING KAYENTA 02 $561,695 CONSTRUCT NEW RUNWAY, TAXIWAY AND...APRON KAYENTA (SITE PREPARATION) (GENERAL AVIATION) KINGMAN 04 $138,411 INSTALL RUNWAY LIGHTING, TAXIWAY MOHAVE COUNTY GUIDANCE SIGNS AND VISUAL APPROACH

X-ray face mask and bib device

International Nuclear Information System (INIS)

Forshee, D.J.

1982-01-01

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)

Exposure of Medical Staff during Interventional Procedures

International Nuclear Information System (INIS)

Osvay, M.; Turak, O.

2013-01-01

The medical staff during interventional procedures receives significant doses on their hands, or parts of their body not covered with protective shielding equipment, as they are close to X-rays field. It can be stated, that interventional radiology and cardiology have one of the highest doses among the X-ray diagnostic procedures. The radiologist use X-ray machine directly in the interventional procedures. The occupational dose is measured only by one Kodak film badge worn under the lead apron for the estimation of the effective dose in Hungary. Our lecture presents the results of dose measurements on eye lens, hands, knees using LiF thermoluminescent dosemeters on the medical staff of two Hungarian hospitals. Results suggest that wearing only one film badge (or other dosemeter system) under the lead apron does not provide proper information on the real occupational dose of medical staff.(author)

Falling aprons at circular piers under currents

NARCIS (Netherlands)

De Sonneville, B.; Van Velzen, G.; Verheij, H.J.; Dorst, K.

2012-01-01

Traditional guidelines on rock protection at circular piers predominantly focus on preventing shear failure (by choosing a sufficiently large rock size), winnowing failure (by designing an appropriate filter) and edge failure (by selecting a sufficient extent). In particular areas (e.g. in an

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.

Preliminary assessment of the dose to the interventional radiologist in fluoro-CT-guided procedures

International Nuclear Information System (INIS)

Pereira, M. F.; Alves, J. G.; Sarmento, S.; Santos, J. A. M.; Sousa, M. J.; Gouvea, M.; Oliveira, A. D.; Cardoso, J. V.; Santos, L. M.

2011-01-01

A preliminary assessment of the occupational dose to the intervention radiologist received in fluoroscopy computerised tomography (CT) used to guide the collection of lung and bone biopsies is presented. The main aim of this work was to evaluate the capability of the reading system as well as of the available whole-body (WB) and extremity dosemeters used in routine monthly monitoring periods to measure per procedure dose values. The intervention radiologist was allocated 10 WB detectors (LiF: Mg, Ti, TLD-100) placed at chest and abdomen levels above and below the lead apron, and at both right and left arms, knees and feet. A special glove was developed with casings for the insertion of 11 extremity detectors (LiF:Mg, Cu, P, TLD-100H) for the identification of the most highly exposed fingers. The H p (10) dose values received above the lead apron (ranged 0.20-0.02 mSv) depend mainly on the duration of the examination and on the placement of physician relative to the beam, while values below the apron are relatively low. The left arm seems to receive a higher dose value. H p (0.07) values to the hand (ranged 36.30-0.06 mSv) show that the index, middle and ring fingers are the most highly exposed. In this study, the wrist dose was negligible compared with the finger dose. These results are preliminary and further studies are needed to better characterise the dose assessment in CT fluoroscopy. (authors)

A phantom study on fetal dose reducing factors in pregnant patients with breast cancer during radiotherapy treatment

Directory of Open Access Journals (Sweden)

Akın Ogretici

2017-01-01

Full Text Available Purpose: This study aims to investigate the factors that reduce fetal dose in pregnant patients with breast cancer throughout their radiation treatment. Two main factors in a standard radiation oncology center are considered as the treatment planning systems (TPSs and simple shielding for intensity modulated radiation therapy technique. Materials and Methods: TPS factor was evaluated with two different planning algorithms: Anisotropic analytical algorithm and Acuros XB (external beam. To evaluate the shielding factor, a standard radiological purpose lead apron was chosen. For both studies, thermoluminescence dosimeters were used to measure the point dose, and an Alderson RANDO-phantom was used to simulate a female pregnant patient in this study. Thirteen measurement points were chosen in the 32nd slice of the phantom to cover all possible locations of a fetus up to 8th week of gestation. Results: The results show that both of the TPS algorithms are incapable of calculating the fetal doses, therefore, unable to reduce them at the planning stage. Shielding with a standard lead apron, however, showed a slight radiation protection (about 4.7% to the fetus decreasing the mean fetal dose from 84.8 mGy to 80.8 mGy, which cannot be disregarded in case of fetal irradiation. Conclusions: Using a lead apron for shielding the abdominal region of a pregnant patient during breast irradiation showed a minor advantage; however, its possible side effects (i.e., increased scattered radiation and skin dose should also be investigated further to solidify its benefits.

Seismic Risk Assessment of Italian Seaports Using GIS

International Nuclear Information System (INIS)

Bartolomei, Anna; Corigliano, Mirko; Lai, Carlo G.

2008-01-01

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)

Propagule pressure determines recruitment from a commercial shipping pier.

Science.gov (United States)

Hedge, Luke H; Johnston, Emma L

2012-01-01

Artificial structures associated with shipping and boating activities provide habitats for a diverse suite of non-indigenous marine species. Little is known about the proportion of invader success in nearby waters that is attributable to these structures. Areas close to piles, wharves and piers are likely to be exposed to increasing levels of propagule pressure, enhancing the recruitment of non-indigenous species. Recruitment of non-indigenous and native marine biofouling taxa were evaluated at different distances from a large commercial shipping pier. Since artificial structures also represent a desirable habitat for fish, how predation on marine invertebrates influences the establishment of non-indigenous and native species was also evaluated. The colonisation of several non-indigenous marine species declined rapidly with distance from the structure. Little evidence was found to suggest that predators have much influence on the colonisation success of marine sessile invertebrate species, non-indigenous or otherwise. It is suggested that propagule pressure, not predation, more strongly predicts establishment success in these biofouling assemblages.

Seismic Risk Assessment of Italian Seaports Using GIS

Science.gov (United States)

Bartolomei, Anna; Corigliano, Mirko; Lai, Carlo G.

2008-07-01

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).

The most effective strategy for recruiting a pregnancy cohort : A tale of two cities

NARCIS (Netherlands)

Manca, D.P.; O'Beirne, M.; Lightbody, T.; Johnston, D.W.; Dymianiw, D.L.; Nastalska, K.; Anis, L.; Loehr, S.; Gilbert, A.; Kaplan, B.J.; APrON Study Team, the; Pop, V.J.M.

2013-01-01

Background Pregnant women were recruited into the Alberta Pregnancy Outcomes and Nutrition (APrON) study in two cities in Alberta, Calgary and Edmonton. In Calgary, a larger proportion of women obtain obstetrical care from family physicians than from obstetricians; otherwise the cities have similar

Dødsulykker ved bygningsbrande

DEFF Research Database (Denmark)

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

1998-01-01

%) and 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...

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... able to see, hear and speak with your child at all times. A parent may be allowed in the room but will be required to wear a lead apron to prevent radiation exposure. The radiation ... child. Some imaging facilities may use general anesthesia or ...

Decommissioning of the SPERT-III large leach pond at the Idaho National Engineering Laboratory. Final report

International Nuclear Information System (INIS)

Bradford, J.D.

1984-04-01

This report describes the decontamination and decommissioning of the SPERT-III large leach pond. Prior to decontamination and decommissioning the pond basin was enclosed by a mesh and barbed wire fence. An 8-in. carbon steel discharge pipe ran from the SPERT-III reactor building to the pond basin. The outlet of the discharge pipe rested on a concrete apron in the pond basin. The soil in the pond basin contained low-level radioactive contamination. The fence and apron were removed, radiologically surveyed, found to be uncontaminated, and sent to the sanitary landfill for disposal. The discharge pipe was left buried in place. The pond basin was backfilled with radiologically clean soil to reduce the surface activity to background. The area was then seeded with crested wheatgrass. A permanent marker was erected at the center of the pond basin to indicate the presence of subsurface radioactive contamination and the location of the buried discharge pipe. 5 references, 32 figures, 2 tables

Effects of noise pollution over the blood serum immunoglobulins and auditory system on the VFM airport workers, Van, Turkey.

Science.gov (United States)

Akan, Zafer; Körpinar, Mehmet Ali; Tulgar, Metin

2011-06-01

Noise pollution is a common health problem for developing countries. Especially highways and airports lead to noise pollution in different levels and in many frequencies. In this study, we focused on the effect of noise pollution in airports. This work aimed measurements of noise pollution levels in Van Ferit Melen (VFM) airport and effect of noise pollution over the immunoglobulin A, G, and M changes among VFM airport workers in Turkey. It was seen that apron and terminal workers were exposed to high noise (>80 dB(A)) without any protective precautions. Noise-induced temporary threshold shifts and noise-induced permanent threshold shifts were detected between the apron workers (p  0.05). These findings suggested that the noise pollution in the VFM airport could lead to hearing loss and changes in blood serum immunoglobulin levels of airport workers. Blood serum immunoglobulin changes might be due to vibrational effects of noise pollution. Airport workers should apply protective precautions against effect of noise pollution in the VFM airport.

Potential gonadal dose from leakage radiation?

International Nuclear Information System (INIS)

Nicholson, R.A.

1995-01-01

The author draws attention to the potential dangers of leakage radiation from mobile image intensifier units, and points out that during interventional urological procedures, radiation from below the urologist's knees may irradiate male gonads without being intercepted by protective aprons. Results are presented for a Shimatzu WHA mobile II, phantom doses being measured with an ionization chamber. Dose rates measured in the male gonad position were compared with rates at waist level behind a 0.35 mm lead equivalent shielding and dose rates at collar level outside the lead apron. Results are also presented of a study on the effect on gonad dose of a) adding 0.7 mm lead shielding to the tube housing and b) adding 0.7 mm lead and removing the spacer cone to reduce scatter. Results show that it is possible for gonad doses to be comparable with those assumed for the eyes, rather than the body. (Author)

A Cohort Study on Meniscal Lesions among Airport Baggage Handlers

DEFF Research Database (Denmark)

Mikkelsen, Sigurd; Brauer, Charlotte; Pedersen, Ellen Bøtker

2016-01-01

and then decreased slowly to reach unity after approximately 30 years, adjusted for effects of potential confounders. This relation between baggage handling and meniscal lesions was present for work on the apron which involves lifting in a kneeling or squatting position, but not in the baggage hall, which only...

77 FR 22376 - Airport Improvement Program (AIP) Grant Assurances

Science.gov (United States)

2012-04-13

... established after December 30, 1987, will be expended by it for the capital or operating costs of the airport... structures (such as runways, taxiways, aprons, terminal buildings, hangars, and roads), including all... the Airport and Airway Trust Fund. * * * * * Issued in Washington, DC on April 10, 2012. Benito De...

Teachers' Talk about Robotics: Where Is the Mathematics?

Science.gov (United States)

Savard, Annie; Highfield, Kate

2015-01-01

Programming and the use of robotics present affordances for mathematics learning with application across a broad range of ages. However, realising these affordances in the classroom requires educators to recognise and build apron these potential opportunities for learning. This paper reports one component of a larger study, examining teacher…

What Is Meant by the Term "Group" Mentoring?

Science.gov (United States)

Kroll, Jonathan

2016-01-01

Much like traditional dyadic mentoring experiences, group mentorship has been practiced since time immemorial. Benjamin Franklin, for example, as a young entrepreneur created the Leather Apron Club, a group mentoring experience for a select group of Philadelphia tradesmen. Since the late 1990s, when group mentoring became a serious focus of…

In vitro Seed-dressing Technique for the Control of Seed-borne ...

African Journals Online (AJOL)

In vitro Seed-dressing Technique for the Control of Seed-borne Fungi of Rice variety Faro -29. ... Journal of Applied Sciences and Environmental Management ... Fernasan-D, Apron Plus 50 DS and Dithane–M45), and soaking and slurry methods at various concentrations, for the control of seed-borne fungi of rice variety

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…

48 CFR 3052.236-70 - Special precautions for work at operating airports.

Science.gov (United States)

2010-10-01

... within the existing aprons shall be the electric type of not less than 100 watts intensity placed and... electric or battery type lights. These lights and flags shall be placed so as to outline the construction...) Trucks and other motorized equipment entering the airport or construction area shall do so only over...

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

Observations of obsidian lava flow emplacement at Puyehue-Cordón Caulle, Chile

Science.gov (United States)

Tuffen, H.; Castro, J. M.; Schipper, C. I.; James, M. R.

2012-04-01

The dynamics of obsidian lava flow emplacement remain poorly understood as active obsidian lavas are seldom seen. In contrast with well-documented basaltic lavas, we lack observational data on obsidian flow advance and temporal evolution. The ongoing silicic eruption at Puyehue-Cordón Caulle volcanic complex (PCCVC), southern Chile provides an unprecedented opportunity to witness and study obsidian lava on the move. The eruption, which started explosively on June 4th 2011, has since June 20 generated an active obsidian flow field that remains active at the time of writing (January 2012), with an area of ~6 km2, and estimated volume of ~0.18 km3. We report on observations, imaging and sampling of the north-western lava flow field on January 4th and 10th 2012, when vent activity was characterised by near-continuous ash venting and Vulcanian explosions (Schipper et al, this session) and was simultaneously feeding the advancing obsidian flow (Castro et al, this session). On January 4th the north-western lava flow front was characterised by two dominant facies: predominant rubbly lava approximately 30-40 m thick and mantled by unstable talus aprons, and smoother, thinner lobes of more continuous lava ~50 m in length that extended roughly perpendicular to the overall flow direction, forming lobes that protrude from the flow margin, and lacked talus aprons. The latter lava facies closely resembled squeeze-up structures in basaltic lava flows[1] and appeared to originate from and overlie the talus apron of the rubbly lava. Its upper surface consisted of smooth, gently folded lava domains cut by crevasse-like tension gashes. During ~2 hours of observation the squeeze-up lava lobe was the most frequent location of small-volume rockfalls, which occurred at ~1-10 minute intervals from the flow front and indicated a locus of lava advance. On January 10th the squeeze-up lava lobes had evolved significantly, with disruption and breakage of smooth continuous lava surfaces to form

Learning the easy way.

Science.gov (United States)

1998-03-01

This article describes the program activities of a 1-day seminar and training course that was organized by the Japan International Cooperation Agency (JICA). Participants included high-ranking government officials from education directorates from 12 countries and officers from the National Women's Education Center. The training course relied on two innovative IEC materials developed by JOICFP. The two IEC materials were portable, durable kits that provided visual guides to learning about reproductive health (RH). The Magnel Kit includes a metal white board with almost life-size illustrations of male and female reproductive organs and magnetized vinyl images that teach about the menstrual cycle, pregnancy stages, contraception, and sexually transmitted diseases. Maggie the Apron is a durable apron with transparent pockets for placing cards with images relating to menstruation, pregnancy, and contraception. The apron is light in weight, cost-effective, and easily folded for storage and portability. Participants were particularly interested in the use of the two IEC materials in adolescent sexual health education. The clear visual materials offer the option of teaching according to the level of understanding of the audience. The materials can be used in any country, since there are no printed texts or narration. The training introduced participants to a community-based approach to family planning and maternal-child health services, which were successful in Japan for raising the level of health. The approach is used by JOICFP in its program efforts in developing countries. The training introduced participants to the role of community women in promoting RH through the presentation of a case study from Bangladesh. Participants watched the JOICFP still-image video "Moni's Milestone," a story about a woman's life in Bangladesh, and a video on the family planning movement in Japan, "First Step in Family Planning in Japan."

Repair Aircraft Parking Apron at Naval Station Norfolk

Science.gov (United States)

2010-03-10

in the finaJ contract. The associated funds have been identifi ed for reaJ.ignment to other ARRA projec ts. ~9-.c..~ Gladys J . Commons Assistant Secretary of the Navy (Financial Management and Comptroller) Comments 25

Evaluation of the integrity of radiological protection clothing used in veterinary radiology

Energy Technology Data Exchange (ETDEWEB)

Rosa, Paola da Costa; Barros, Frieda Saicla; Costa, Douglas Siqueira da, E-mail: paah_dacosta@hotmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Curso Superior de Tecnologia em Radiologia e Programa de Pos-Graduacao em Engenharia Biomedica

2017-11-01

This study aimed to evaluate the integrity of radiological protection clothing used by veterinarians in veterinary radiology facilities, and whether they are available in an adequate quantity for the team. Inspection was performed by palpation, followed by X-ray scanning in 189 clothing from 29 veterinary facilities. The results indicate that 5% of the clothes evaluated in this study were considered inadequate due to the failure of the integrity of the lead, being most lead aprons. All facilities have at least two lead aprons and one Thyroid protectors. 24% of the facilities have lead glasses, pointing to a risk to veterinarians by radiosensitivity of the eyes. Also, 24% of the facilities do not have lead gloves, which also presents a risk due to the hand's exposure to the primary beam. Most lead clothing has shield equivalence of 0.5mmPb. The method used in the study was effective in attesting the adequacy of lead clothing. It is recommended to periodically evaluate clothing to ensure that users are always protected. (author)

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

International Nuclear Information System (INIS)

Kim, Seon Chil

2008-01-01

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.

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.

Evaluation of the integrity of radiological protection clothing used in veterinary radiology

International Nuclear Information System (INIS)

Rosa, Paola da Costa; Barros, Frieda Saicla; Costa, Douglas Siqueira da

2017-01-01

This study aimed to evaluate the integrity of radiological protection clothing used by veterinarians in veterinary radiology facilities, and whether they are available in an adequate quantity for the team. Inspection was performed by palpation, followed by X-ray scanning in 189 clothing from 29 veterinary facilities. The results indicate that 5% of the clothes evaluated in this study were considered inadequate due to the failure of the integrity of the lead, being most lead aprons. All facilities have at least two lead aprons and one Thyroid protectors. 24% of the facilities have lead glasses, pointing to a risk to veterinarians by radiosensitivity of the eyes. Also, 24% of the facilities do not have lead gloves, which also presents a risk due to the hand's exposure to the primary beam. Most lead clothing has shield equivalence of 0.5mmPb. The method used in the study was effective in attesting the adequacy of lead clothing. It is recommended to periodically evaluate clothing to ensure that users are always protected. (author)

Health interventions for the metal working industry: which is the most cost-effective? A study from a developing country.

Science.gov (United States)

Salinas, A M; Villarreal, E; Nuñez, G M; Garza, M E; Briones, H; Navarro, O

2002-05-01

This study ranked the cost-effectiveness of health interventions in the metal working industry in a developing country. Data were based on 82 034 workers of the Northern region of Mexico. Effectiveness was measured through 'healthy life years' (HeaLYs) gained. Costs were estimated per worker according to type and appropriate inputs from selected health interventions. 'Hand' was the anatomical region that yielded the most gain of HeaLYs and amputation was the injury that yielded the most gain of HeaLYs. The most effective health intervention corresponded to training, followed by medical care, education, helmets, safety shoes, lumbar supports, safety goggles, gloves and safety aprons. In dollar terms, education presented the best cost-effectiveness ratio (US$637) and safety aprons presented the worst cost-effectiveness ratio (US$1 147 770). Training proved to be a very expensive intervention, but presented the best effectiveness outcome and the second best cost-effectiveness ratio (US$2084). Cost-effectiveness analyses in developing countries are critical. Corporations might not have the same funds and technology as those in developed countries or multinational companies.

Installation Restoration Program. Phase 2 - Confirmation/ Quantification. Stage 2 for McChord Air Force Base, Washington

Science.gov (United States)

1986-04-30

canadensis), beaver (Castor canadensis), muskrat (Ondatra zibethica), and mink ( Mustela vison ). Mule or blacktail deer (Oedocoileus hemionus), raccoon...aprons, blouse, trousers) C. Respiratory protection using half-facepiece air purifying res- pirator with replaceable filter cartridges 1...Hierarchy of protective controls: engineered, admini- strative, work practice, personal protective clothing and eq- ^.pment. J-6 2. Forms of respiratory

Sadhana | Indian Academy of Sciences

Indian Academy of Sciences (India)

Scour around bridge pier is the main reason for the failure of bridges. The local scour around the pier causes exposure of the foundation and may lead to undermining of the structure. Different types of protection measures such as the provision of raft, apron, sheet piles, etc. can be used as scour protectionmeasures. One of ...

Deep and superficial infrapatellar bursae: cadaveric investigation of regional anatomy using magnetic resonance after ultrasound-guided bursography

Energy Technology Data Exchange (ETDEWEB)

Viegas, Flavio C.; Trudell, Debbie J.; Haghighi, Parviz; Resnick, Donald [Veterans Affairs Medical Center - San Diego, San Diego, CA (United States); Aguiar, Rodrigo O.C. [Veterans Affairs Medical Center - San Diego, San Diego, CA (United States); Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Gasparetto, Emerson; Marchiori, Edson [Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

2007-01-15

To demonstrate the anatomy of the deep and superficial infrapatellar bursae using magnetic resonance (MR) imaging and anatomic correlation in cadavers. MR imaging of the infrapatellar bursae of nine cadaveric knees was performed after ultrasound-guided bursography. The images were compared with those seen on anatomic sectioning. Histologic analysis was obtained in two specimens. The deep infrapatellar bursa (DIB) was visualized in all specimens (n=9) and the superficial infrapatellar bursa (SIB) in five specimens (55%). The mean dimensions of the DIB in the craniocaudal, mediolateral, and anteroposterior planes were respectively 25, 28.7, and 6 mm, and for SIB 19.5, 21.2 and 2.2 mm. A fat apron dividing the DIB was depicted in eight knees (89%). Lateral extension of the DIB beyond the patellar tendon was observed in 100% of cases. Cadaveric analysis depicted a thin septum in the SIB in four of five cases (80%). The DIB is generally present and extends beyond the lateral margin of the patellar tendon. A fat apron partially separating this structure is usual. The SIB is not an unusual finding and may have a septum separating its compartments. (orig.)

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

International Nuclear Information System (INIS)

Khoury, Helen Jamil; Silveira, Marcia Maria Fonseca da; Couto, Geraldo Bosco Lindoso; Brasileiro, Izabela Vanderley

2005-01-01

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.

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)

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.

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)

Klasic, B.; Knezevic, Z.; Vekic, B.; Brnic, Z.; Novacic, K.

2006-01-01

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)

Minimizing exposure in nuclear medicine through optimum use of shielding devices

International Nuclear Information System (INIS)

Rutherford, B.L.; King, S.H.; Erdman, M.C.; Miller, K.L.

1991-01-01

Exposure to radiation from nuclear medicine nuclides can be minimized through the use of various shielding devices. This paper reviews the dose reductions achieved through use of various syringe shields, lead aprons, leaded gloves, and several types of eyeglass lenses for 67 Ga, 99m Tc, 131 I and 201 Tl. The authors have found that combination of devices can best provide for minimizing doses

Installation Restoration Program Phase 2. Confirmation/Quantification Stage 2. Bulk Fuel Storage Area Fuel Spill Investigation.

Science.gov (United States)

1987-10-01

Kirkwood Formations are locally hydraulicai ly connected. The Vincentown Formation contains water in localized water- bearing beds that may yield...investigation of landfill sites, industrial waste disposal assessment, evalua- tion of soil mass stability a.\\a bearing capacity at proposed sites of... Eyeglasses ( ) None (y) Other ^T.?1*- To c_ %\\g Clothinc ) Fully Encapsulating Sui’ ) Chemically Resistant Sol ash Suit ) Apron, Specify ^A) Tyvek

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.

Radiation shielding in dental radiography

International Nuclear Information System (INIS)

Stenstroem, B.; Rehnmark-Larsson, S.; Julin, P.; Richter, S.

1983-01-01

The protective effect in the thyroid region from different types of radiation shieldings at intraoral radiography has been studied as well as the reduction of the absorbed dose to the sternal and the gonadal regions. The shieldings tested were five different types of leaded aprons, of which three had an attached leaded collar and the other two were used in combination with separate soft leaded collars. Furthermore one of the soft leaded collars and an unflexible horizontal leaded shield were tested separately. Two dental x-ray machines of 60 and 65 kVp with rectangular and circular tube collimators were used. The exposure time corresponded to speed group E film. The absorbed doses were measured with two ionization chambers. No significant difference in the protective effect in the thyroid gland could be found between the different types of radiation shieldings. There was a dose reduction by approximately a factor of 2 to the thyroid region down to 0.08 mGy per full survey using parallelling technique, and below 0.001 mGy per single bitewing exposure. The shieldings reduced the thyroid dose using bisecting-angle technique by a factor of 5 down to 0.15 mGy per full survey (20 exposures). In the sternal region the combinations of apron and collar reduced the absorbed dose from a full survey to below 2 μGy compared with 18 μGy (parallelling) and 31 μGy (biscting-angle) without any shielding. With the horizontal leaded shield a reduction by a factor of 6 was obtained but no significant sternal dose reduction could be detected from the soft collar alone. The gonadal dose could be reduced by a factor of 10 with the horizontal leaded shield, parallelling technique and circular collimator. Using leaded aprons the gonadal dose was approximately one per cent of the dose without any shielding, i.e. below 0.01 μGy per single intraoral exposure. (Authors)

Organ doses of the cardiologists and their assistants during interventional cardiology procedures at teaching general hospitals in Mashhad/ Iran

International Nuclear Information System (INIS)

Bahreyni Toosi, M.; Zare, H.; Bayani, Sh.; Esmaili, S.

2006-01-01

Full text of publication follows: Protection of medical personnel in interventional cardiology is now days one of the most important issues of radiological protection. Due to the rapid increase of coronary heart disease in developed and developing countries, application of interventional techniques such as coronary angiography and angioplasty have also increased sharply over past two decades. While these procedures are carried out cardiologists and their assistants are remained close to the patient and within the hot area of the radiation field. Therefore they are subject to receive significant doses of radiation. In this study doses received by critical and more vulnerable organs of cardiologists and their assistants were measured by thermoluminescent dosimeters (T.L.D.). T.L.D. measurements were carried for 115 coronary angiography (C.A.) and 30 pre-cutaneous transluminal coronary angioplasty (P.T.C.A.) procedures at teaching general hospitals in Mashhad-Iran. Doses received by thyroid, gonad, right and left hands of the study groups were measured. For this purpose T.L.D. were placed on and underneath of the lead apron adjacent to gonads and on the wrist of both hands. The results of this study imply that: a) For both groups left hands are subject to receiving the highest mean dose (0.18 mGy/P.T.C.A.) b) Thyroid mean dose per P.T.C.A. received by the T.L.D. chips on the shield is 0.72 mGy and is much higher than corresponding value for the T.L.D. placed underneath the shield. c) Gonads would receive the highest mean dose per P.T.C.A. (0.16 mGy), second to left hand, if lead apron is not worn, but lead apron reduces the dose by a factor of nearly six. d) General speaking assistants, mostly stood on the right side of cardiologists, receive smaller dose. e) P.T.C.A. induces a higher dose to all organs of both cardiologists and their assistants when compared with the corresponding doses arising from C.A. procedure. (authors)

Organ doses of the cardiologists and their assistants during interventional cardiology procedures at teaching general hospitals in Mashhad/ Iran

Energy Technology Data Exchange (ETDEWEB)

Bahreyni Toosi, M.; Zare, H.; Bayani, Sh.; Esmaili, S. [Mashhad University of Medical Sciences, Medical Physics Dep., Faculty of Medicine, Mashhad (Iran, Islamic Republic of)

2006-07-01

Full text of publication follows: Protection of medical personnel in interventional cardiology is now days one of the most important issues of radiological protection. Due to the rapid increase of coronary heart disease in developed and developing countries, application of interventional techniques such as coronary angiography and angioplasty have also increased sharply over past two decades. While these procedures are carried out cardiologists and their assistants are remained close to the patient and within the hot area of the radiation field. Therefore they are subject to receive significant doses of radiation. In this study doses received by critical and more vulnerable organs of cardiologists and their assistants were measured by thermoluminescent dosimeters (T.L.D.). T.L.D. measurements were carried for 115 coronary angiography (C.A.) and 30 pre-cutaneous transluminal coronary angioplasty (P.T.C.A.) procedures at teaching general hospitals in Mashhad-Iran. Doses received by thyroid, gonad, right and left hands of the study groups were measured. For this purpose T.L.D. were placed on and underneath of the lead apron adjacent to gonads and on the wrist of both hands. The results of this study imply that: a) For both groups left hands are subject to receiving the highest mean dose (0.18 mGy/P.T.C.A.) b) Thyroid mean dose per P.T.C.A. received by the T.L.D. chips on the shield is 0.72 mGy and is much higher than corresponding value for the T.L.D. placed underneath the shield. c) Gonads would receive the highest mean dose per P.T.C.A. (0.16 mGy), second to left hand, if lead apron is not worn, but lead apron reduces the dose by a factor of nearly six. d) General speaking assistants, mostly stood on the right side of cardiologists, receive smaller dose. e) P.T.C.A. induces a higher dose to all organs of both cardiologists and their assistants when compared with the corresponding doses arising from C.A. procedure. (authors)

Dentition of the apron ray Discopyge tschudii (Elasmobranchii: Narcinidae).

Science.gov (United States)

Spath, M C; Deli Antoni, M; Delpiani, G

2017-10-01

The present study provides quantitative and qualitative analyses of the dentition of Discopyge tschudii. Overall, 193 individuals (99 males and 94 females) of D. tschudii were collected on scientific trawl surveys conducted by the National Institute for Fisheries Research and Development (INIDEP) and commercial vessels in Argentina. Discopyge tschudii has rhombic-shaped teeth, arranged in a semipavement-like dentition; each tooth has an erect cusp slightly inclined posteriorly and holaulachorized root. Mature males have greater tooth lengths than females and immature specimens. Discopyge tschudii exhibits dignathic homodonty and gradient monognathic heterodonty where teeth of the commissural row are shorter than those of the symphyseal and internal rows. © 2017 The Fisheries Society of the British Isles.

Glass FRP reinforcement in rehabilitation of concrete marine infrastructure

International Nuclear Information System (INIS)

Newhook, John P.

2006-01-01

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)

The most effective strategy for recruiting a pregnancy cohort: A tale of two cities

OpenAIRE

Manca, D.P.; O'Beirne, M.; Lightbody, T.; Johnston, D.W.; Dymianiw, D.L.; Nastalska, K.; Anis, L.; Loehr, S.; Gilbert, A.; Kaplan, B.J.; APrON Study Team, the; Pop, V.J.M.

2013-01-01

Background Pregnant women were recruited into the Alberta Pregnancy Outcomes and Nutrition (APrON) study in two cities in Alberta, Calgary and Edmonton. In Calgary, a larger proportion of women obtain obstetrical care from family physicians than from obstetricians; otherwise the cities have similar characteristics. Despite similarities of the cities, the recruitment success was very different. The purpose of this paper is to describe recruitment strategies, determine which were most successfu...

The most effective strategy for recruiting a pregnancy cohort: a tale of two cities

OpenAIRE

Manca, Donna P; O?Beirne, Maeve; Lightbody, Teresa; Johnston, David W; Dymianiw, Dayna-Lynn; Nastalska, Katarzyna; Anis, Lubna; Loehr, Sarah; Gilbert, Anne; Kaplan, Bonnie J

2013-01-01

Background Pregnant women were recruited into the Alberta Pregnancy Outcomes and Nutrition (APrON) study in two cities in Alberta, Calgary and Edmonton. In Calgary, a larger proportion of women obtain obstetrical care from family physicians than from obstetricians; otherwise the cities have similar characteristics. Despite similarities of the cities, the recruitment success was very different. The purpose of this paper is to describe recruitment strategies, determine which were most successfu...

Radiodiagnosis for the woman of childbearing age

International Nuclear Information System (INIS)

Guillemette-Artur, P.; Feuillet, B.; Duchateau, C.; Feidt, C.; Reynaud, J.P.; Le Bot, Y.; Marjou, F.

2009-01-01

The pregnancy irradiation must be avoided wherever possible, this pregnancy known or not. A safe radiodiagnosis can be realised when the uterus is out of the irradiated field. The risks for the child are variables in function of the pregnancy term and the irradiation itself. Wearing a lead apron does not change significantly the dose received at uterus, but may be useful to the psychological comfort. (N.C.)

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

OpenAIRE

Álvaro, J. Javier; Ezzouhairi, Hassan; Clausen, Sébastien; Ribeiro, Maria Luísa; Solá, Ana Rita

2015-01-01

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 geometrie...

US Highway 395 Widen Median and Shoulder and Install Rumble Strips Project Environmental Assessment, Edwards Air Force Base, California

Science.gov (United States)

2015-12-16

Topography of the area varies from rugged rocky mountaintops, surrounded by gravel-laden alluvial fans and aprons, to sand and clay deposits in flat valley...disposal practices resulted in releases or disposal of organic solvents that have affected groundwater. A sanitary landfill is also located in this...Great Basin scrub, Sonoran Desert scrub and desert dunes with sandy flats, dunes and sandy areas around clay slicks with Sarcobatus (greasewood

Use of Terrestrial Laser Scanner for Rigid Airport Pavement Management

Directory of Open Access Journals (Sweden)

Maurizio Barbarella

2017-12-01

Full Text Available The evaluation of the structural efficiency of airport infrastructures is a complex task. Faulting is one of the most important indicators of rigid pavement performance. The aim of our study is to provide a new method for faulting detection and computation on jointed concrete pavements. Nowadays, the assessment of faulting is performed with the use of laborious and time-consuming measurements that strongly hinder aircraft traffic. We proposed a field procedure for Terrestrial Laser Scanner data acquisition and a computation flow chart in order to identify and quantify the fault size at each joint of apron slabs. The total point cloud has been used to compute the least square plane fitting those points. The best-fit plane for each slab has been computed too. The attitude of each slab plane with respect to both the adjacent ones and the apron reference plane has been determined by the normal vectors to the surfaces. Faulting has been evaluated as the difference in elevation between the slab planes along chosen sections. For a more accurate evaluation of the faulting value, we have then considered a few strips of data covering rectangular areas of different sizes across the joints. The accuracy of the estimated quantities has been computed too.

Use of Terrestrial Laser Scanner for Rigid Airport Pavement Management.

Science.gov (United States)

Barbarella, Maurizio; D'Amico, Fabrizio; De Blasiis, Maria Rosaria; Di Benedetto, Alessandro; Fiani, Margherita

2017-12-26

The evaluation of the structural efficiency of airport infrastructures is a complex task. Faulting is one of the most important indicators of rigid pavement performance. The aim of our study is to provide a new method for faulting detection and computation on jointed concrete pavements. Nowadays, the assessment of faulting is performed with the use of laborious and time-consuming measurements that strongly hinder aircraft traffic. We proposed a field procedure for Terrestrial Laser Scanner data acquisition and a computation flow chart in order to identify and quantify the fault size at each joint of apron slabs. The total point cloud has been used to compute the least square plane fitting those points. The best-fit plane for each slab has been computed too. The attitude of each slab plane with respect to both the adjacent ones and the apron reference plane has been determined by the normal vectors to the surfaces. Faulting has been evaluated as the difference in elevation between the slab planes along chosen sections. For a more accurate evaluation of the faulting value, we have then considered a few strips of data covering rectangular areas of different sizes across the joints. The accuracy of the estimated quantities has been computed too.

Occupational eye lens doses in interventional cardiology. A multicentric study

International Nuclear Information System (INIS)

Sánchez, R M; Vano, E; Fernández, J M; Pifarré, X; Ordiales, J M; Rovira, J J; Carrera, F; Goicolea, J; Fernández-Ortiz, A

2016-01-01

New European regulation regarding radiological protection of workers and more specifically the new occupational dose limit for the eye lens recently reduced to 20 mSv yr −1 may affect interventional cardiologists. This paper presents a set of measurements of occupational doses performed in five interventional cardiology centres and then compared with the new dose limit. The measurement of occupational doses was performed over the apron at chest level using electronic dosemeters recording H p (10). In one of the centres, scatter dose at goggles was also measured with optically stimulated luminescence dosemeters calibrated in terms of H p (0.07). An average H p (10) over the apron of 46 μSv/procedure was measured for cardiologists. Lower doses were noted in other professionals like second cardiologists, nurses or anaesthetists. Procedures for valvular and other structural heart diseases involved the highest occupational doses, averaging over 100 μSv/procedure. Important differences in occupational doses among centres may be indicative of different radiation protection habits. The new occupational dose limit for the eye lens is likely to be exceeded by those among the interventionalists who do not use protection tools (ceiling suspended screen and/or goggles) even with standard workloads. (paper)

Radiation Exposure of Interventional Radiologists During Computed Tomography Fluoroscopy-Guided Renal Cryoablation and Lung Radiofrequency Ablation: Direct Measurement in a Clinical Setting

Energy Technology Data Exchange (ETDEWEB)

Matsui, Yusuke, E-mail: wckyh140@yahoo.co.jp; Hiraki, Takao, E-mail: takaoh@tc4.so-net.ne.jp; Gobara, Hideo, E-mail: gobara@cc.okayama-u.ac.jp; Iguchi, Toshihiro, E-mail: i10476@yahoo.co.jp; Fujiwara, Hiroyasu, E-mail: hirofujiwar@gmail.com; Kawabata, Takahiro, E-mail: tkhr-kwbt@yahoo.co.jp [Okayama University Medical School, Department of Radiology (Japan); Yamauchi, Takatsugu, E-mail: me9248@hp.okayama-u.ac.jp; Yamaguchi, Takuya, E-mail: me8738@hp.okayama-u.ac.jp [Okayama University Hospital, Central Division of Radiology (Japan); Kanazawa, Susumu, E-mail: susumu@cc.okayama-u.ac.jp [Okayama University Medical School, Department of Radiology (Japan)

2016-06-15

IntroductionComputed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking.Materials and MethodsRadiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator’s finger skin was measured using thermoluminescent dosimeter rings.ResultsThe mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator’s finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA.ConclusionRadiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.

Radiation Exposure of Interventional Radiologists During Computed Tomography Fluoroscopy-Guided Renal Cryoablation and Lung Radiofrequency Ablation: Direct Measurement in a Clinical Setting.

Science.gov (United States)

Matsui, Yusuke; Hiraki, Takao; Gobara, Hideo; Iguchi, Toshihiro; Fujiwara, Hiroyasu; Kawabata, Takahiro; Yamauchi, Takatsugu; Yamaguchi, Takuya; Kanazawa, Susumu

2016-06-01

Computed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking. Radiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator's finger skin was measured using thermoluminescent dosimeter rings. The mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator's finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA. Radiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.

Radiation burden to personal during surgical and urological reentgenology

Energy Technology Data Exchange (ETDEWEB)

Doubravsky, J; Kukacka, R

1976-01-01

The radiation load was measured in surgical personnel during operation of femoral neck fracture and during instrumental urological roentgenology, using film dosimetry. Here are the conclusions: (1) It is obligatory for medical personnel to use protective lead-rubber aprons during surgical and urological roentgenology. At surgical examinations, where the surgeon stands at the operating table, a short apron, covering the lower half of the body, may suffice. (2) Skiascopy, being the chief source of radiation load, should be reduced to the shortest possible time. (3) When handling the patient or film holder, protective gloves should be worn and the primary radiation beam avoided. (4) Clinical workers should be repeatedly instructed, both in theory and practice, how to work with X radiation sources. (5) In larger clinics with intensive roentgenological services the workers should be rotated; nurses should not be in the reproductive age. For newly established uro-roentgenological examination rooms the regional hygiene officer may issue regulations limiting the number of examinations per day and per person. (6) Non-roentgenologists participating in roentgenological examinations should be provided with dosimeters and included in compulsory preventive periodical examinations in accordance with the regulation ''Mandatory Measures No. 49/1967, Directives Concerning Medical Fitness for Work''.

Experience with Dismantling of the Analytic Cell in the JRTF Decommissioning Program

International Nuclear Information System (INIS)

Annoh, Akio; Nemoto, Koichi; Tajiri, Hideo; Saito, Keiichiro; Miyajima, Kazutoshi; Myodo, Masato

2003-01-01

The analytic cell was mainly used for process control analysis of the reprocessing process and for the measurement of fuel burn up ratio in JAERI's Reprocessing Test Facility (JRTF). The analytic cell was a heavy shielded one and equipped with a conveyor. The cell was alpha and beta(gamma)contaminated. For dismantling of analytic cells, it is very important to establish a method to remove the heavy shield safely and reduce the exposure. At first, a green house was set up to prevent the spread out of contamination, and next, the analytic cell was dismantled. Depending on the contamination condition, the workers wore protective suits such as air ventilated-suits for prevention of internal exposure and vinyl chloride aprons, lead aprons in order to reduce external exposure. From the work carried out, various data such as needed manpower for the activities, the collective dose of workers by external exposure, the amount of radioactive wastes and the relation between the weight of the shield and its dismantling efficiency were obtained and input for the database. The method of dismantling and the experience with the dismantling of the analytic cell in the JRTF, carried out during 2001 and 2002, are described in this paper

Study of the examination times using radiation equipments and the radiation exposure control

Energy Technology Data Exchange (ETDEWEB)

Koshida, Kichiro; Orito, Takeo; Maekawa, Ryuichi; Hiraki, Tatsunosuke [Kanazawa Univ. (Japan). School of Paramedicine; Koga, Sukehiko

1985-01-01

The relation between the examination time and the exposure to the personnel was investigated. In order to minimize radiation injury, special exposure dose-rate distribution curves were performed at the maximum exposure condition setting the phantom, and the examination times could be limited from the exprosure dose for the place where the personnel presented. The examination times are possible to be ten times by those with the Medical X-ray Protective Aprons.

Geometry of the proximal part of the modern turbidite depositional system of the Carapebus Formation, Campos Basin: a model for reservoir heterogeneities; Geometria da porcao proximal do sistema deposicional turbiditico moderno da Formacao Carapebus, Bacia de Campos; modelo para heterogeneidades de reservatorio

Energy Technology Data Exchange (ETDEWEB)

Machado, Luis Claudio Ribeiro; Kowsmann, Renato Oscar; Almeida Junior, Waldemar de; Murakami, Celso Yoshihito; Schreiner, Simone; Miller, Dennis James; Piauilino, Pedro Orlando Vasconcelos [PETROBRAS, Rio de Janeiro, RJ (Brazil). Exploracao e Producao. Unidade de Servico Submarino]. E-mail: machadolc@petrobras.com.br

2004-11-01

The deep-water marine sedimentary environment of the Cenozoic of the Campos Basin is examined at the modern sea floor, where it can be better understood. This environment is responsible for the genesis of the turbidite systems of the Carapebus Formation, the reservoirs that hold more than 90% of Brazil's petroleum reserves. The study was developed with the records of regional side-scan sonar, swath bathymetry, sub-bottom profiler data, standard multichannel 3D seismic surveys and piston cores covering almost the entire basin. After leaving the Almirante Camara Canyon, the turbiditic flows erode the muddy debris apron surrounding the continental slope and begin to deposit thick layers of clean sand into a big trough in water depths of 1800 m to 3000 m. The trough is 3.5 km wide, 150 m deep, 150 km long, and is formed by a chain of salt withdrawal mini-basins. In some places the sea floor is flat enough to develop today a depositional lobe, in all aspects analogous to the best, geologically ancient petroleum reservoirs in the basin. Aspects of the system: 1) the arcosean sands are brought by the river, cross the shelf, the incised valley, the canyon, and deposit as turbidites - they do not originate from a collapse of the continental slope; 2) a wide muddy debris apron surrounds the continental slope (slope apron), and represents a huge volume of sediment in the Campos Basin ; 3) the turbidites do not develop a submarine fan, but are deposited in an elongated trough formed by salt tectonics; 4) the turbidite beds, both in the lobe or in the trough, are not deposited during a single episode, but in multiple events over significant geologic time in which small channels which brought the turbidites avulse and meander along the entire depositional area, building a single amalgamated bed; 5) classic channel-levees are not present because this system comprises a sandy braid plain and the levees are as sandy as the channel; 6) a hierarchical depositional model for bulb

Double dosimetry procedures for the determination of occupational effective dose in interventional radiology

International Nuclear Information System (INIS)

Jaervinen, H.; Buls, N.; Clerinx, P.; Miljanic, S.; Ranogajec-Komor, M.; Nikodemova, D.; D'Errico, F.

2008-01-01

Full text: In interventional radiology, for an accurate determination of occupational effective dose, measurements with two dosemeters ('double dosimetry', DD) have been recommended, one dosemeter located above and one under the protective apron. In this paper, based on an extensive literature search, the most recent algorithms developed for the determination of effective dose from the dosimeter readings have been compared for a few practical interventional procedures. Recommendations on the practices and algorithms are given on the basis of the results. For the comparison of algorithms, dosemeter readings and the effective dose were obtained both experimentally and by calculation. Further, data from published Monte Carlo calculations have been applied. The literature review has indicated that very few regulations for DD exist and the DD practices have not been harmonized. There is no firm consensus on the most suitable calculation algorithms. Single dosemeter (SD) measurements are still mostly used for the calculation of effective dose. Most DD and SD algorithms overestimate effective dose significantly, sometimes by over ten times. However, SD algorithms can significantly underestimate effective dose in certain interventional radiology conditions. Due to the possibility of underestimating effective dose, DD is generally recommended. The results suggest that there might not be a single DD algorithm which would be optimum for all interventional radiology procedures. However, the selection of a precise DD algorithm for each individual condition is not practical and compromises must be made. For accurate personnel dosimetry, the accuracy of the algorithm selected should be tested for typical local interventional radiology condition. Personnel dosemeters should be used in the recommended positions. The dosemeter above the apron should be on a collar and its reading also used to assess the risk of lens injuries. The dosemeter under the apron can be on the chest or

Cutting the apron strings: the South African experience of decolonisation

Directory of Open Access Journals (Sweden)

G E Devenish

2013-12-01

Full Text Available Decolonisation is a recurring constitutional and political theme in the process of change and reform in South Africa’s history during the 20th century. The constitutional emancipation of the erstwhile Union of South Africa and the subsequent internal decolonisation of designated black ethnic population and cultural groups, are two kindred processes which have interesting similarities, but also important differences. The former involved British Imperialism, the latter involved Afrikaner Nationalism and African Nationalism. The former was a natural, legitimate and spontaneous process, the latter was an artificial process that was induced by Afrikaner Nationalism, that was spurned internationally and domestically by the the international community of nations and indigenous people of South Africa respectively. The article examines the legitimacy of the process of the decolonisation of the Union of South Africa resulting in its independence, followed by the adoption of a republican form of government. In contrast, a comparison is made with the controversial and questionable evolution of the Bantustans, which emerged out of the erstwhile native reserves, a stratagem designed in effect to thwart the liberation struggle for a truly democratic form of government for all the people of South Africa. This pseudo decolonisation was an analogous process to that of genuine decolonisation. The former involved political fragmentation, whatever it was designated, that in effect, denied to the indigenous people, freedom and liberation for decades. As an odyssey it was a very protracted and painful process. Ultimately, in a belated and circuitous manner, after the inordinate suffering and oppression of South Africa’s indigenous people, a genuine democracy in a unified and consolidated state for all the people of South Africa was to transpire. This was liberation and not decolonisation, and was the final stage in the historic and traumatic process for South Africa. It is also argued that only with the inception of the Interim Constitution, following the first historic democratic election of 27 April 1994, did South Africa and its people adopt an authentic democratic and republican constitution. Keywords: Union of South Africa, Status, dominions, decolonisation, liberation movements, Afrikaner nationalism, African nationalism.

Effectiveness of combinations of raft foundation with aprons as a ...

Indian Academy of Sciences (India)

B A Vijayasree

2018-03-10

Mar 10, 2018 ... bridge projects vary from exposed hard rock to pure sand for a considerable .... arrangements were made to dissipate the energy during inletting of water .... This endorsed the fact that the use of raft foundation in Case 2 reduced the ... at the downstream side, which extended to the wake region of horseshoe ...

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.;

Large Crater Repair at Silver Flag Exercise Site, Tyndall Air Force Base, Florida

Science.gov (United States)

2015-08-01

fiberglass mat ( FFM ) survived medium-speed braking events and was deemed suitable for use on taxiways and aprons. 2. The current USAF FFM system failed...braking events due to failure of the connector bushings. After replacement with more robust connector bushings from the FFM system, the FRP system...withstood the high-speed taxi events that caused the FFM to fail. ERDC/GSL TR-15-27 2 4. AM2 aluminum matting was successfully tested as a suitable

Material selection and embodied energy

CSIR Research Space (South Africa)

Ampofo-Anti, N

2010-11-01

Full Text Available mix concrete apron Non reinforced, ready mix concrete strip foundation Non reinforced, ready mix ground floor slab Concrete block Modular, hollow concrete block Solid concrete block Finishes Floor screed Insulated ceiling panel Perlite... Predicting the embodied energy contribution of a single material is however not as easy as green building practices assume. As illustrated by the example in Box 1, the choice of a material implies the choice of integral constituents such as insulation...

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

International Nuclear Information System (INIS)

1995-09-01

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

PREPARATION OF TEASER RAMS BY LATERAL DEVIATION OF PREPUCE AND PENIS

OpenAIRE

Rashid Ahmad

2003-01-01

For oestrus detection in sheep while in flocks, limited exposure is given to rams with tied apron in front of their prepucial opening. For better and un-feared use of rams for oestrus detection and for effect of , ram exposure on postpartum reproductive characteristics of ewes, rams before the attainment of puberty and those sexually mature (adult rams) were operated for lateral deviation of prepuce and penis. The operations were successful, no post operative complications were recorded and t...

Analisis Higiene dan Sanitasi Staf Instalasi Gizi Rumah Sakit Umum Daerah Kota Langsa Tahun 2013

OpenAIRE

Faizia, El

2013-01-01

Implementation of food in the hospital depends on hygiene and sanitation so that the food does not become a source of disease transmission to humans who consume the food. Implementation of food at the General Hospital Langsa power levels for installation nutrition wear headgear, gloves, masks, and some have not wear aprons while working, talking and there is smoke on the job. This research purposes to analyze the condition of nutrient installation hygiene and sanitasi at Langsa city hospit...

A novel dosimeter for measuring the amount of radiation exposure of surgeons during percutaneous nephrolithotomy: Instadose?

OpenAIRE

Yuruk, Emrah; Gureser, Gokhan; Tuken, Murat; Ertas, Kasim; Serefoglu, Ege Can

2016-01-01

Introduction The aim of this study was to demonstrate the efficacy of Instadose?, a novel dosimeter designed for radiation workers to provide a measurement of the radiation dose at any time from any computer; to determine the amount of radiation exposure during percutaneous nephrolithotomy (PNL); and to evaluate the factors that affect the amount of radiation exposed. Material and methods Two experienced surgeons wore Instadose? on the outer part of their lead aprons during the PNL procedures...

Study of the examination times using radiation equipments and the radiation exposure control

International Nuclear Information System (INIS)

Koshida, Kichiro; Orito, Takeo; Maekawa, Ryuichi; Hiraki, Tatsunosuke; Koga, Sukehiko.

1985-01-01

It was investigated for the relation between the examination times and the exposure to the personnel. At the purpose to minimize the radiation injury, the special exposure dose-rate distribution curves were performed at the maximum exposure condition setting the phantom, and the examination times could be limited from the exprosure dose for the place where the personnel presented. The examination times are possible to be ten times by those with the Medical X-ray Protective Aprons. (author)

The Ash Warriors

Science.gov (United States)

2000-01-01

toys, formula, portable crib, stroller, etc) Water supply for one day Food/ snacks for one day Food for pets (3 days) and leash POVs should have one-half...Clark’s continued. On June 7, a dome appeared on Pinatubo’s northwest face. Increased seismic activity and the extruding dome prompted the volcanologists...MWR) peo- ple passed out bottled water, snacks and other comfort items. The lines on the parking apron were long but kept moving. Personnel special

[Ecological risk evaluation of heavy metals of the typical dredged mud in Shanghai].

Science.gov (United States)

Tang, Qing-Li; Cheng, Jin-Ping; Gao, Hao-Min; Yao, Lei; Jiang, Zhen-Yi; Wu, Yang; Xie, Cui-Song; Liang, Hai; Wang, He; Pi, Shuai-Shuai; Yu, Zhao-Yi

2013-04-01

In order to discuss the potential ecological risk of heavy metals of the typical dredged mud in Shanghai, the Hakanson potential ecological risks method was used to analyse and assess the potential ecological risks of heavy metals, including Hg, Cd, Cu, Pb, As,Cr and Zn in dredged mud from the following three areas-the dock apron of Huangpu River, the mouth of the Yangtze River and inland waterways. The results showed that the mean values of ecological risk index (Er(i)) of the seven heavy metals are 20.05, 17.49, 8.82, 5.71, 4.68, 1.74 and 1.13, respectively, all of which belonged to the low ecological risk; Cd (one location in inland waterways) and Hg (three locations in the mouth of the Yangtze River and one location in inland waterways) are the most hazardous elements, with the Er(i) > 40, which belonged to the medium ecological risk or the high ecological risk, and other elements belonged to the low ecological risk. From the results of ecological risk indices(ERI) of the heavy metals in Shanghai dredged mud, the risk of the heavy metals belonged to the low ecological risk. The ERI of inland waterways, the mouth of the Yangtze River and the dock apron of the Huangpu River were 81.4, 57.7 and 52.5, respectively, which all belong to the low ecological risk.

Women who take n-3 long-chain polyunsaturated fatty acid supplements during pregnancy and lactation meet the recommended intake.

Science.gov (United States)

Jia, Xiaoming; Pakseresht, Mohammadreza; Wattar, Nour; Wildgrube, Jamie; Sontag, Stephanie; Andrews, Murphy; Subhan, Fatheema Begum; McCargar, Linda; Field, Catherine J

2015-05-01

The aim of the current study was to estimate total intake and dietary sources of eicosapentaenoic acid (EPA), docosapentanoic (DPA), and docosahexaenoic acid (DHA) and compare DHA intakes with the recommended intakes in a cohort of pregnant and lactating women. Twenty-four-hour dietary recalls and supplement intake questionnaires were collected from 600 women in the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort at each trimester of pregnancy and 3 months postpartum. Dietary intake was estimated in 2 ways: by using a commercial software program and by using a database created for APrON. Only 27% of women during pregnancy and 25% at 3 months postpartum met the current European Union (EU) consensus recommendation for DHA. Seafood, fish, and seaweed products contributed to 79% of overall n-3 long-chain polyunsaturated fatty acids intake from foods, with the majority from salmon. The estimated intake of DHA and EPA was similar between databases, but the estimated DPA intake was 20%-30% higher using the comprehensive database built for this study. Women who took a supplement containing DHA were 10.6 and 11.1 times more likely to meet the current EU consensus recommendation for pregnancy (95% confidence interval (CI): 6.952-16.07; PDHA during pregnancy and lactation, but taking a supplement significantly improved the likelihood that they would meet recommendations.

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

International Nuclear Information System (INIS)

Costa, R.F.

2015-01-01

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)

Both Mother and Infant Require a Vitamin D Supplement to Ensure That Infants' Vitamin D Status Meets Current Guidelines.

Science.gov (United States)

Aghajafari, Fariba; Field, Catherine J; Weinberg, Amy R; Letourneau, Nicole

2018-03-29

We examined the association between maternal vitamin D intake during breastfeeding with their infants' vitamin D status in infants who did or did not receive vitamin D supplements to determine whether infant supplementation was sufficient. Using plasma from a subset of breastfed infants in the APrON (Alberta Pregnant Outcomes and Nutrition) cohort, vitamin D status was measured by liquid chromatography-tandem mass spectrometry. Maternal and infants' dietary data were obtained from APrON's dietary questionnaires. The median maternal vitamin D intake was 665 International Units (IU)/day, while 25% reported intakes below the recommended 400 IU/day. Of the 224 infants in the cohort, 72% were exclusively breastfed, and 90% were receiving vitamin D supplements. Infants' median 25(OH)D was 96.0 nmol/L (interquartile ranges (IQR) 77.6-116.2), and 25% had 25(OH)D < 75 nmol/L. An adjusted linear regression model showed that, with a 100 IU increase in maternal vitamin D intake, infants' 25(OH)D increased by 0.9 nmol/L controlling for race, season, mid-pregnancy maternal 25(OH)D, birthweight, and whether the infant received daily vitamin D supplement (β = 0.008, 95% confidence interval (CI) 0.002, 0.13). These results suggest that, to ensure infant optimal vitamin D status, not only do infants require a supplement, but women also need to meet current recommended vitamin D intake during breastfeeding.

Occupational doses in medical staff during hemodynamic procedures

International Nuclear Information System (INIS)

Alonso, Thessa C.; Silva, Teogenes A. da

2008-01-01

The main objective of an occupational radiation program for workers is to keep radiation exposures under control and to assure that radiation protection principles are followed. Due to different types of interventionist medical exams, usually the medical staffs are highly exposed to radiation, which it emphasizes that it is required safety procedures for dose reduction. In this work, studies were concerned with individual doses of medical staff that are directly engaged to interventionist procedures at hemodynamic services. Dose values from a data bank of the CDTN Individual Monitoring Service (IMS) were analyzed and measurements with film type and thermoluminescent (TL) dosimeters were performed for comparison purposes. Additionally, the influence of the use of a lead apron on the individual dose was investigated. Results suggested that the medical staff does not care about wearing the routine personal dosimeter and that the registered doses may not be representative to the actual annual effective doses. They also showed that effective doses are highly dependent on the characteristics and conditions of the lead apron that is worn by the medical staff. It is concluded that it is important to have personal dosimetric system up-graded for reliable measurements, to define an adequate algorithm for determining the effective dose and to train the medical staff to follow the basic radiation protection principle of optimization. (author)

A pilot experience launching a national dose protocol for vascular and interventional radiology

International Nuclear Information System (INIS)

Vano, E.; Segarra, A.; Fernandez, J. M.; Ordiales, J. M.; Simon, R.; Gallego, J. J.; Del Cerro, J.; Casasola, E.; Verdu, J. F.; Ballester, T.; Sotil, J.; Aspiazu, A.; Garcia, M. A.; Moreno, F.; Carreras, F.; Canis, M.; Soler, M. M.; Palmero, J.; Ciudad, J.; Diaz, F.; Hernandez, J.; Gonzalez, M.; Rosales, P.

2008-01-01

The design of a national dose protocol for interventional radiology has been one of the tasks during the European SENTINEL Coordination Action. The present paper describes the pilot experience carried out in cooperation with the Spanish Society on Vascular and Interventional Radiology (SERVEI). A prospective sample of procedures was initially agreed. A common quality control of the X-ray systems was carried out, including calibration of the air kerma area product (KAP) meters. Occupational doses of the radiologists involved in the survey were also included in the survey. A total of 10 Spanish hospitals with interventional X-ray units were involved. Six hundred and sixty-four patient dose data were collected from 397 diagnostic and 267 therapeutic procedures. Occupational doses were evaluated in a sample of 635 values. The obtained KAP median/mean values (Gy.cm 2 ) for the gathered procedures were: biliary drainage (30.6/68.9), fistulography (4.5/9.8), lower limb arteriography (52.2/60.7), hepatic chemoembolisation (175.8/218.3), iliac stent (45.9/73.2) and renal arteriography (39.1/59.8). Occupational doses (mean monthly values, in mSv) were 1.9 (over apron); 0.3 (under apron) and 4.5 (on hands). With this National experience, a protocol was agreed among the SENTINEL partners to conduct future similar surveys in other European countries. (authors)

Hydraulic mechanism of siltation in approach channels and harbors. Siltation ni yoru koroter dot hakuchi maibotsu no suiri kiko ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Irie, I [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering; Murakami, K; Tsuruya, H [Ministry of Transportation, Tokyo (Japan). Port and Harbour Research Inst.

1991-11-20

The phenomena that clay or mud is carried away by waves or currents and deposited in approach channels and harbors are called siltation, and hinder often seriously the navigation of vessels and their arrival at as well as departure from wharves, etc.. In this paper, the hydraulic mechanism of siltation in harbors and approach channels in the sea area is chozen in particular, and waves and currents as the external force governing the travel of bottom mud, the properties of sunken mud, the supply source of sunken mud in approach channels, and grasping of the mud sinking mechanism as well as countermeasures against mud sinking are stated mainly centering around the results obtained from the in situ observations at Kumamoto Port and Banjarmasin Port and their mathematical calculations. The bottom mud traveling mechanism has been accepted as a study subject respectively from such wide viewpoints as river engineering, agriculture, environmental engineering, sanitary engineering, chemical engineering and mechanical engineering, and in addition, it has been under study by coastal engineering. Siltation under the wave actions is still in the state of research even in advanced countries in America and Europe. The siltation research in Japan has a short history, but this is the field which must be coped with positively. 19 refs., 17 figs.

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.

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

International Nuclear Information System (INIS)

Stanko, V.; Uhlikova, Z.; Babor, L.

1979-01-01

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.)

Methodology of high dose research in medical radiodiagnostic

International Nuclear Information System (INIS)

Barboza, Adriana E.; Martins, Cintia P. de S.

2013-01-01

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

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.

Considerations for evaluation and selection of solid waste handling apron conveyors

Energy Technology Data Exchange (ETDEWEB)

Lisiecki, H.G.

1976-11-01

Criteria to be used in evaluating and selecting conveyer equipment for facilities handling solid wastes, such as solid waste resource recovery facilities, are discussed. Types of conveyer pan design and chain mechanisms are described. It is concluded that the conveyer purchaser must be knowledgeable about the equipment available, the specific use of equipment, its performance specifications, and the overall maintenance and operating costs. (LCL)

Politicians in apron: case study of rebel health services in Nepal.

Science.gov (United States)

Devkota, Bhimsen; van Teijlingen, Edwin R

2009-10-01

This article presents the findings of a systematic review on the health consequences of Nepal's armed conflict waged by the Maoists and the development and trajectory of their health workers. Nepal's decade-long violent conflict resulted in more than 13,000 deaths, the destruction of more than 1000 health posts and poor health services delivery. At present, most of the former rebel health workers live in remote/rural areas and some are running health centers. The review found that the Maoists had trained more than 2000 health workers, who can be categorized into 4 levels. However, there is little evidence on their competencies and career motivation. The Maoists demand restructuring of the Nepalese health sector and the integration of their health workforce into the national health system. However, there has been no national discussion in Nepal of what kind of health reform and integration model is appropriate for a sustainable peace and improved service delivery.

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

NARCIS (Netherlands)

Harris, C.H.

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

Dosimetric essay in dental radiology; Experiencia dosimetrica en radiologia odontologica

Energy Technology Data Exchange (ETDEWEB)

Lopez Salaberry, M [Ministerio de Industria, Energia y Mineria, Montevideo (Uruguay). Direccion Nacional de Tecnologia Nuclear; Dato Carfagna, A; Rodriguez Dorgia, R [Universidad de la Republica, Facultad de Odontologia , Montevideo (Uruguay)

1999-12-31

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

Dosimetric essay in dental radiology

International Nuclear Information System (INIS)

Lopez Salaberry, M.

1998-01-01

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

OCCUPATIONAL DOSE DURING ADULT INTERVENTIONAL CARDIOLOGY: FIRST VALUES WITH PERSONAL ACTIVE DOSIMETERS IN CHILE.

Science.gov (United States)

Ubeda, Carlos; Morales, Claudio; Gutiérrez, Diego; Oliveira, Marcus; Manterola, Carlos

2018-05-11

The objective of this article is to present initial occupational dose values using digital active personal dosimeters for medical staff during adult interventional cardiology procedures in a public hospital in Chile. Personal dose equivalent Hp(10) over the lead apron of physician, nurse and radiographer were measured during 59 procedures. Mean values of occupational dose Hp(10) per procedure were 47.6, 6.2 and 4.3 μSv for physician, nurse and radiographer, respectively. If no protective tools are used, physician dose can exceed the new eye lens dose limit.

PREPARATION OF TEASER RAMS BY LATERAL DEVIATION OF PREPUCE AND PENIS

Directory of Open Access Journals (Sweden)

Rashid Ahmad

2003-07-01

Full Text Available For oestrus detection in sheep while in flocks, limited exposure is given to rams with tied apron in front of their prepucial opening. For better and un-feared use of rams for oestrus detection and for effect of , ram exposure on postpartum reproductive characteristics of ewes, rams before the attainment of puberty and those sexually mature (adult rams were operated for lateral deviation of prepuce and penis. The operations were successful, no post operative complications were recorded and these rams exhibited normal libido and were found efficient for oestrus detection in ewes.

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

International Nuclear Information System (INIS)

Sousa, C.H.S.; Teixeira, G.J.; Peixoto, J.G.P.; Menezes, I.V.; Medeiros, D.O.; Nunes, M.M.; Pinheiro, R.A.; Bernardes, P.M.B.; Oliveira, D.

2014-01-01

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)

Development of gonad protectors to be used in children radiology from recycled materials; Desenvolvimento de protetores de gonadas para uso em radiologia pediatrica a partir de materiais reciclados

Energy Technology Data Exchange (ETDEWEB)

Sousa, C.H.S.; Teixeira, G.J.; Peixoto, J.G.P., E-mail: chenrique@ird.gov.br [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Menezes, I.V.; Medeiros, D.O.; Nunes, M.M.; Pinheiro, R.A.; Bernardes, P.M.B. [Hospital Copa D' Or, Rio de Janeiro, RJ (Brazil); Oliveira, D. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

2014-07-01

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)

Dental radiology in preventive dentistry

Energy Technology Data Exchange (ETDEWEB)

Stallard, J S; Stallard, R E [Group Health Plan, Minnesota (USA)

1975-02-01

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.

Perinatal nutrition in maternal mental health and child development: Birth of a pregnancy cohort.

Science.gov (United States)

Leung, Brenda M Y; Giesbrecht, Gerald F; Letourneau, Nicole; Field, Catherine J; Bell, Rhonda C; Dewey, Deborah

2016-02-01

Mental disorders are one of the leading contributors to the global burden of disease. The Alberta Pregnancy Outcomes and Nutrition (APrON) study was initiated in 2008 to better understand perinatal environmental impacts on maternal mental health and child development. This pregnancy cohort was established to investigate the relationship between the maternal environment (e.g. nutritional status), maternal mental health status, birth outcomes, and child development. The purpose of this paper is to describe the creation of this longitudinal cohort, the data collection tools and procedures, and the background characteristics of the participants. Participants were pregnant women age 16 or older, their infants and the biological fathers. For the women, data were collected during each trimester of pregnancy and at 3, 6, 12, 24, and 36months after the birth of their infant. Maternal measures included diet, stress, current mental and physical health, health history, and lifestyle. In addition, maternal biological samples (DNA, blood, urine, and spot breast milk samples) were banked. Paternal data included current mental and physical health, health history, lifestyle, and banked DNA samples. For infants, DNA and blood were collected as well as information on health, development and feeding behavior. At the end of recruitment in 2012, the APrON cohort included 2140 women, 2172 infants, and 1417 biological fathers. Descriptive statistics of the cohort, and comparison of women who stayed in the study and those who dropped out are discussed. Findings from the longitudinal cohort may have important implications for health policy and clinical practice. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

Costa, Paulo Roberto; Groff, Sybele Guedes de Paulo

2009-01-01

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 5.0·10 -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 mGy TLD /month measured with the TLDs outside the apron, the fetal dose calculated by the software was 0.02 mSv/month. (author)

KARAKTERISTIK KOMUNITAS NEMATODA DI PADANG GOLF SUKARAME (PGS BANDAR LAMPUNG

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I Gede Swibawa dan Titik Nur Aeny .

2012-02-01

Full Text Available ABSTRACT Characteristic of  Nematodes Community at PGS Golf Course Bandar Lampung. Golf course is a unique ecosystem where plant parasitic nematodes inhabit and become  important pest because they reduce the quality of the grass.  The pest problems on golf course can be indicated by its characteristics of nematode community.  Survey on nematodes community at PGS Golf Course Bandar Lampung was conducted from March to December 2004.  The objective was to study the characteristics of nematode community in the part of golf courses hole (green, collar, apron, and fairway.  Soil samples were taken from five holes each of it consists of green, collar, apron, and fairway, respectiveley.  Nematodes extraction was done in Laboratory of Arthropod Pest, Department of Plant Protection University of Lampung.   The result showed that at least 50 nematodes genera of 28 families inhabit PGS. The number of plant parasitic nematode genera was higher than the free-living one.  The characteristic of nematodes community on green and collar was different than on faiway. Nematode abundance and diversity on green and collar were higher than on fairway.  Based on abundance of nematode feeding group, maturity index of free-living nematodes (MI and that of plant parasitic nematodes (PPI, green and collar part seemed to be more favorable to plant parasitic nematodes than free-living nematodes. The contrary happened for fairway.  Four most dominant genera of plant parasitic nematodes on PGS golf course were Helicotylenchus, Hoplolaimus, Criconemella, and Xiphinema.

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

International Nuclear Information System (INIS)

Shikone, Mitsuru; Tsuchida, Atsushi; Tateno, Hidemi; Uchimura, Noboru; Higaki, Morio; Kanno, Masanori; Higashi, Tomomitsu

1986-01-01

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)

Occupational exposure for workers in interventional radiological examination

International Nuclear Information System (INIS)

Suliman, E.E.

2005-01-01

Full text: An interventional radiological examination is a diagnostic or therapeutic in any organ or anatomical region using images acquired with ionizing radiation. Compared to other radiological acquisition, personnel who perform interventional procedures, which involve long fluoroscopy times and a high workload may receive radiation doses comparable to the dose limits. Therefore to ensure that no person be subjected to an unacceptable risk from radiation, that need for accurate individual monitoring has arisen. In this work, the doses received by physician in cardiac angiography were evaluated and the results of two months were presented. Only 7 physicians were monitored. Hence the data available is presented, and it is hoped to provide some information on the assessment of occupational exposure in interventional radiological examination. Measurements were done using Thermoluminescence dosimeters (TLD) and a calibrated Harshaw Reader. Two TLDs were used by each physician, one worn under a protective apron at the waist (H W ) and the other worn outside and above the apron at the neck (H N ). The effective dose E was estimated from the formula: E (estimated) = 0.5 H W + 0.025 H N . From the result obtained it was concluded that, the weak point of radiation protection philosophy in medical application is in the work of interventional physicians who have no full time decision like the radiologist physicians and therefore haven't enough knowledge about the radiation and radiation protection. So they are the highest risk group among physicians and to whom the efforts must be directed. (author)

Transsexual Mastectomy: Selection of Appropriate Technique According to Breast Characteristics

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Hüsamettin Top

2017-04-01

Full Text Available Background: Subcutaneous mastectomy for female- to-male transsexuals is usually the first surgical pro- cedure in sexual reassignment. The main objective of subcutaneous mastectomy is to create an aesthetically pleasing male chest contour by removing all glandular tissue while minimizing chest wall scars. Aims: In this paper, we present our experience with subcutaneous mastectomy performed in female-to- male transsexual patients. The authors recommend their point of view to aid in selecting the most suitable subcutaneous mastectomy technique depending on breast characteristics. Study Design: Retrospective cross-sectional study. Methods: Between March 2011 and December 2014, 52 patients underwent bilateral subcutaneous mastec- tomies (total of 104 mastectomies, performed using the following four techniques: Webster semicircular, concentric circular, vertical, and apron flap. The tech- nique decision depended on the breast size, degree of skin excess, skin elasticity, chest width, nipple areolar complex size and position. Results: Seventeen patients (32.7% were operated with Webster semicircular, 7 patients (13.5% with con- centric periareolar, 12 patients with vertical (23%; and 16 patients (30.8% with the apron flap technique. The overall postoperative complication rate was 13.4%. All patients were satisfied with the aesthetic results of their subcutaneous mastectomies within the follow-up period. Conclusion: To obtain higher patient satisfaction with aesthetic results and lower postoperative complication rates, breast characteristics are evaluated in a detailed fashion, while choosing the ideal technique of Female-to-Male (FtM subcutaneous mastectomy. The presented surgical new algorithm facilitates the selection of the most reliable surgical technique

Microbial counts of food contact surfaces at schools depending on a feeding scheme

Directory of Open Access Journals (Sweden)

Nthabiseng Nhlapo

2014-11-01

Full Text Available The prominence of disease transmission between individuals in confined environments is a concern, particularly in the educational environment. With respect to school feeding schemes, food contact surfaces have been shown to be potential vehicles of foodborne pathogens. The aim of this study was to assess the cleanliness of the surfaces that come into contact with food that is provided to children through the National School Nutrition Programme in central South Africa. In each school under study, microbiological samples were collected from the preparation surface and the dominant hand and apron of the food handler. The samples were analysed for total viable counts, coliforms, Escherichia coli, Staphylococcus aureus and yeasts and moulds. The criteria specified in the British Columbia Guide for Environmental Health Officers were used to evaluate the results. Total viable counts were high for all surfaces, with the majority of colonies being too numerous to count (over 100 colonies per plate. Counts of organisms were relatively low, with 20% of the surfaces producing unsatisfactory enumeration of S. aureus and E. coli and 30% unsatisfactory for coliforms. Yeast and mould produced 50% and 60% unsatisfactory counts from preparation surfaces and aprons, respectively. Statistically significant differences could not be established amongst microbial counts of the surfaces, which suggests cross-contamination may have occurred. Contamination may be attributed to foodstuffs and animals in the vicinity of the preparation area rather than to the food handlers, because hands had the lowest counts of enumerated organisms amongst the analysed surfaces.

Dosimetry Measurements around the Angiography Units Using Thermoluminescence Detectors (TLD)

International Nuclear Information System (INIS)

Salah El-den, T.; Shahein, A.Y.; Gomaa, M.A.

2008-01-01

The thermoluminescent dosimeters (TLDs) are widely used not only in the field of personnel monitoring (dosimetry) service for ionizing radiation to medical, and research communities, but also for measurements of X-rays emitted from different angiography's unit. Measurements ionizing radiation around the bed area during cardiac catheterization procedures using X-rays was measured. TLD Badges used to determine the annual effective doses, the safe distance for the staff to minimize radiation exposure and the effectiveness of shield and used leaded apron. The results indicated that annual effective dose for by angiography cardiac Catheterization room may exceed the limits

Risk of whole body radiation exposure and protective measures in fluoroscopically guided interventional techniques: a prospective evaluation

Directory of Open Access Journals (Sweden)

Rivera Jose

2003-08-01

Full Text Available Abstract Background Fluoroscopic guidance is frequently utilized in interventional pain management. The major purpose of fluoroscopy is correct needle placement to ensure target specificity and accurate delivery of the injectate. Radiation exposure may be associated with risks to physician, patient and personnel. While there have been many studies evaluating the risk of radiation exposure and techniques to reduce this risk in the upper part of the body, the literature is scant in evaluating the risk of radiation exposure in the lower part of the body. Methods Radiation exposure risk to the physician was evaluated in 1156 patients undergoing interventional procedures under fluoroscopy by 3 physicians. Monitoring of scattered radiation exposure in the upper and lower body, inside and outside the lead apron was carried out. Results The average exposure per procedure was 12.0 ± 9.8 seconds, 9.0 ± 0.37 seconds, and 7.5 ± 1.27 seconds in Groups I, II, and III respectively. Scatter radiation exposure ranged from a low of 3.7 ± 0.29 seconds for caudal/interlaminar epidurals to 61.0 ± 9.0 seconds for discography. Inside the apron, over the thyroid collar on the neck, the scatter radiation exposure was 68 mREM in Group I consisting of 201 patients who had a total of 330 procedures with an average of 0.2060 mREM per procedure and 25 mREM in Group II consisting of 446 patients who had a total of 662 procedures with average of 0.0378 mREM per procedure. The scatter radiation exposure was 0 mREM in Group III consisting of 509 patients who had a total 827 procedures. Increased levels of exposures were observed in Groups I and II compared to Group III, and Group I compared to Group II. Groin exposure showed 0 mREM exposure in Groups I and II and 15 mREM in Group III. Scatter radiation exposure for groin outside the apron in Group I was 1260 mREM and per procedure was 3.8182 mREM. In Group II the scatter radiation exposure was 400 mREM and with 0.6042 m

Geology of the continental margin beneath Santa Monica Bay, Southern California, from seismic-reflection data

Science.gov (United States)

Fisher, M.A.; Normark, W.R.; Bohannon, R.G.; Sliter, R.W.; Calvert, A.J.

2003-01-01

We interpret seismic-reflection data, which were collected in Santa Monica Bay using a 70-in3 generator-injector air gun, to show the geologic structure of the continental shelf and slope and of the deep-water, Santa Monica and San Pedro Basins. The goal of this research is to investigate the earthquake hazard posed to urban areas by offshore faults. These data reveal that northwest of the Palos Verdes Peninsula, the Palos Verdes Fault neither offsets the seafloor nor cuts through an undeformed sediment apron that postdates the last sea level rise. Other evidence indicates that this fault extends northwest beneath the shelf in the deep subsurface. However, other major faults in the study area, such as the Dume and San Pedro Basin Faults, were active recently, as indicated by an arched seafloor and offset shallow sediment. Rocks under the lower continental slope are deformed to differing degrees on opposite sides of Santa Monica Canyon. Northwest of this canyon, the continental slope is underlain by a little-deformed sediment apron; the main structures that deform this apron are two lower-slope anticlines that extend toward Point Dume and are cored by faults showing reverse or thrust separation. Southeast of Santa Monica Canyon, lower-slope rocks are deformed by a complex arrangement of strike-slip, normal, and reverse faults. The San Pedro Escarpment rises abruptly along the southeast side of Santa Monica Canyon. Reverse faults and folds underpinning this escarpment steepen progressively southeastward. Locally they form flower structures and cut downward into basement rocks. These faults merge downward with the San Pedro Basin fault zone, which is nearly vertical and strike slip. The escarpment and its attendant structures diverge from this strike-slip fault zone and extend for 60 km along the margin, separating the continental shelf from the deep-water basins. The deep-water Santa Monica Basin has large extent but is filled with only a thin (less than 1.5-km

Comparative effects of Apron plus 50DS and soil amendment on the ...

African Journals Online (AJOL)

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2005-09-27

Sep 27, 2005 ... 1Institute of Agricultural Research and Training, Obafemi Awolowo University, P.M.B.5029, Moor Plantation, Ibadan, .... I.A.R. and T., Moor. Plantation, Ibadan The unsterilized soil was used to mimic field condition. The pots were set-up on the floor of glass-house using a ..... Allanhold Osman and Co.

Comparative effects of Apron plus 50DS and soil amendment on the ...

African Journals Online (AJOL)

SERVER

2005-09-27

Sep 27, 2005 ... growth yield and food components of soybean (TGX 1485-1D) were studied. Soybean seeds treated with recommended ... The crop is an important oil seed grown as a food crop (Wolf and Cowman, 1975), and is ... leaf spot, soybean rust, charcoal rot, seed decay and brown spot (Akem, 1996). Fungicides ...

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

Energy Technology Data Exchange (ETDEWEB)

Santos, Osvaldir P. dos; Silva, Joao Carlos P.; Silva, Luiz Carlos Reina P.; Cortines, Geraldo, E-mail: osvaldir@ien.gov.br, E-mail: jcarlos@ien.gov.br, E-mail: reina@ien.gov.br, E-mail: gcortines@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2013-07-01

The objective of this study is to propose an improvement in radiological practices involving production, transportation and application of radiopharmaceutical {sup 18}F, 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 {sup 18}FDG. 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 {sup 18}FDG 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 {sup 18}FDG, 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 {sup 18}FDG are analyzed, since its withdrawal from the packing until administration to the patient. (author)

Gene expression programming for prediction of scour depth downstream of sills

Science.gov (United States)

Azamathulla, H. Md.

2012-08-01

SummaryLocal scour is crucial in the degradation of river bed and the stability of grade control structures, stilling basins, aprons, ski-jump bucket spillways, bed sills, weirs, check dams, etc. This short communication presents gene-expression programming (GEP), which is an extension to genetic programming (GP), as an alternative approach to predict scour depth downstream of sills. Published data were compiled from the literature for the scour depth downstream of sills. The proposed GEP approach gives satisfactory results (R2 = 0.967 and RMSE = 0.088) compared to the existing predictors (Chinnarasri and Kositgittiwong, 2008) with R2 = 0.87 and RMSE = 2.452 for relative scour depth.

Examination of optimal radiation quality in the lead equivalent examination of x-ray protective clothing

International Nuclear Information System (INIS)

Inoue, Shinichi; Matsuzawa, Rie; Matsumoto, Mitsuhiro

2004-01-01

The objective of this study was to determine the effective lead thickness of the apron for radiation protective clothing, i.e., the lead equivalent, a method of performing the lead equivalent examination is provided in the Japanese Industrial Standards (JIS). We proposed a method of computation using an attenuation coefficient, and examined the measurement accuracy and optimal radiation quality using both. We were able to compute the lead equivalent with sufficient accuracy when using radiation quality of about 60 keV in the range of radiation quality examined. This technique was also examined in the measurement used for the marketing of radiation protective clothing. (author)

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

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. Copyright © 2012 Elsevier Inc. All rights reserved.

Physician exposure to ionizing radiation during trauma resuscitation: A prospective clinical study

International Nuclear Information System (INIS)

Weiss, E.L.; Singer, C.M.; Benedict, S.H.; Baraff, L.J.

1990-01-01

A prospective study of emergency physician whole body and extremity exposure to ionizing radiation during trauma resuscitation over a three-month period was conducted. Radiation film badges and thermoluminescent dosimeter finger rings were permanently attached to leaded aprons worn by emergency medicine residents during all trauma resuscitations. One set of apron and finger ring dosimeters was designated for the resident who managed the airway and stabilized the neck, when necessary, during cervical spine radiography (A-CS resident). A separate set of dosimeters was designated for the resident supervising the resuscitation. During the study period, 150 major trauma patients requiring 481 radiographic studies were treated. The mean monthly cumulative whole body exposures were 136.7 +/- 85.0 and 103.3 +/- 60.3 mrem for A-CS and supervising residents, respectively. The mean weekly cumulative extremity exposures were 523.3 +/- 611.0 and 46.7 +/- 18.6 mrem for A-CS and supervising residents, respectively. Calculated whole body exposures per patient were 2.7 mrem for the A-CS resident and 2.1 mrem for the supervising resident. Calculated extremity exposures per patient were 41.9 +/- 48.9 and 3.7 +/- 1.5 mrem, respectively. To exceed the annual whole body exposure limit established by the National Council of Radiologic Protection, the A-CS resident, working 200 shifts per year, would have to treat 9.2 trauma patients per shift. To exceed the annual extremity exposure limit, the A-CS resident would have to treat 5.9 trauma patients per shift. Of note, European exposure limits are 10% of current US limits. We conclude that significant exposures may occur to physicians working in trauma centers and that the use of shielding devices is indicated

Occupational dose measurement in interventional cardiology, dosimetry comparison study

International Nuclear Information System (INIS)

Ahmad, A.M.A.

2008-05-01

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)

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.

Estimation of X-radiation protective coats in abdominal angiography

International Nuclear Information System (INIS)

Koshida, Kichiro; Noto, Kimiya; Fukuda, Atsushi; Matsubara, Kosuke; Nakagawa, Hiroto; Kawabata, Chikako

2005-01-01

Medical personnel involved in abdominal angiography are exposed not only to direct radiation but also scattered radiation from inspection tables, patients, image intensifiers, and the beam-limiting system (collimator), among others. Japanese standard JISZ4831 prescribes protective coats of at least 0.25 mm lead equivalent, which is the uniform thickness of lead equivalent. The most commonly used protective coats are 0.25 mm Pb, 0.35 mm Pb, or 0.5 mm Pb in thickness. The weight of a typical protective coat is about 3 kg. While some coats weigh tip to 6 kg, wearing such heavy coats becomes physically burdensome as inspection time increases. The trade-off between physical burden and protection was considered by analyzing the X-ray intensity distribution and attenuation rate of scattered radiation in each position assumed by the medical staff. In the case of inspections performed at an x-ray tube voltage of 80 kV, it may be possible to reduce the weight of the lead rubber apron by about 33%. Namely, the lead thickness can be reduced uniformly by 0.20 mm Pb at 70 cm and 0.05 mm Pb at 100 cm, when the shielding capability of a 0.25 mm thick Pb layer is accepted as the standard at 40 cm above the gonad position. The same range of permeated X-ray dose for the gonad position may be reduced as well. In the case of 110 kV, when the lead thicknesses are 0.30 mm Pb at 40 cm and 70 cm, and 0.10 mm Pb at 100 cm, it is possible to reduce the weight of the lead rubber apron by about 28%. (author)

Cryoseism Vibrational Movement and Sorting of Detritus of Mars' Regolith Bedforms (E.G., ~ Streaks, Gullies): a New, Dry, Midsummer Antarctic Analogue Mechanism

Science.gov (United States)

Ford, A. B.

2015-12-01

"SNAP!, CRACK!, POP!" The sounds reverberated across newly shaded permafrost of unusual talus aprons (Ford & Andersen, 1967; J. Geol., 75, 722-732) of interior Antarctica (lats. >84°S; Thiel, Pensacola mtns.), coming from ice cracking under tensile failure (cryoseisms). Apron regoliths show conspicuously reversed downslope particle-size sorting and downslope-oriented lineations (debris-cleared tracts; stone stripes) formed by vibrational movement of detritus by midsummer, diurnal cracking of ice. Moving laterally by vibrations away from cracks, with downslope component by gravity, finer detritus becomes concentrated downslope from coarser debris of initial cliff fall — winnowed, as if on a gigantic vibrating shaking table. Slopes outside shade zones remain free of cracking. Diurnal midday shading of solar-warmed, debris-mantled permafrost- and glacier-surface ice at low ambient midsummer temperatures produces high strain-loading rates that exceed tensile toughness of inhomogeneous, polycrystalline ice containing zones of older but sealed cracks. This dry, mechanical, cryoseism mechanism is here proposed also for now waterless Mars and other icy Solar System bodies. Regolith features of Mars' cryosphere may appear different from anrarctic analogues owing to likely operation over tens if not hundreds of millions of years longer than on Earth. The strain distributions in tensile failure of ice better explain a common spacing uniformity of many martian linear features than others' proposed origins, and for some "active" streaks and gully channels, TARS, RSL and dune-slipface channels, as well as for dune orthogonality, diurnal moonquakes and asteroid-regolith detrital sorting (e.g., "rubble-pile" 25143-Itokawa). Because periodic shade from topography (canyons, craters, etc.) is needed, the mechanism is not expected on flattish terrains where more normal annual cooling rates produce the common polygonal tensile fracturing of ice

Sedimentary processes in modern and ancient oceanic arc settings: evidence from the Jurassic Talkeetna Formation of Alaska and the Mariana and Tonga Arcs, western Pacific

Science.gov (United States)

Draut, Amy E.; Clift, Peter D.

2006-01-01

Sediment deposited around oceanic volcanic ares potentially provides the most complete record of the tectonic and geochemical evolution of active margins. The use of such tectonic and geochemical records requires an accurate understanding of sedimentary dynamics in an arc setting: processes of deposition and reworking that affect the degree to which sediments represent the contemporaneous volcanism at the time of their deposition. We review evidence from the modern Mariana and Tonga arcs and the ancient arc crustal section in the Lower Jurassic Talkeetna Formation of south-central Alaska, and introduce new data from the Mariana Arc, to produce a conceptual model of volcaniclastic sedimentation processes in oceanic arc settings. All three arcs are interpreted to have formed in tectonically erosive margin settings, resulting in long-term extension and subsidence. Debris aprons composed of turbidites and debris flow deposits occur in the immediate vicinity of arc volcanoes, forming relatively continuous mass-wasted volcaniclastic records in abundant accommodation space. There is little erosion or reworking of old volcanic materials near the arc volcanic front. Tectonically generated topography in the forearc effectively blocks sediment flow from the volcanic front to the trench; although some canyons deliver sediment to the trench slope, most volcaniclastic sedimentation is limited to the area immediately around volcanic centers. Arc sedimentary sections in erosive plate margins can provide comprehensive records of volcanism and tectonism spanning arc may be best reconstructed from sediments of the debris aprons for intervals up to ~ 20 My but no longer, because subduction erosion causes migration of the forearc basin crust and its sedimentary cover toward the trench, where there is little volcaniclastic sedimentation and where older sediments are dissected and reworked along the trench slope.

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.

X-ray protective garment

International Nuclear Information System (INIS)

Wardley, R.B.

1981-01-01

This patent claim relates to a protective apron. It incorporates material comprising an array of at least two superposed sheets prepared from a composition comprising a natural or synthetic polymeric material, optionally in combination with a plasticiser, and, as a filler, a material serving as an x-ray absorber, the outer, or the outer two sheets having on their outer surfaces a decorative and/or protective surface covering, for example, a layer of unfilled rubber or plastics material, the array of superposed sheets being bonded together round its edges, there being unbonded areas between the sheets in regions away from the edges. Bonding may be by welding, adhesion or stitching. (U.K.)

Sutter Buttes-the lone volcano in California's Great Valley

Science.gov (United States)

Hausback, Brain P.; Muffler, L.J. Patrick; Clynne, Michael A.

2011-01-01

The volcanic spires of the Sutter Buttes tower 2,000 feet above the farms and fields of California's Great Valley, just 50 miles north-northwest of Sacramento and 11 miles northwest of Yuba City. The only volcano within the valley, the Buttes consist of a central core of volcanic domes surrounded by a large apron of fragmental volcanic debris. Eruptions at the Sutter Buttes occurred in early Pleistocene time, 1.6 to 1.4 million years ago. The Sutter Buttes are not part of the Cascade Range of volcanoes to the north, but instead are related to the volcanoes in the Coast Ranges to the west in the vicinity of Clear Lake, Napa Valley, and Sonoma Valley.

Radiation exposure of an anaesthesiologist in catheterisation and electrophysiological cardiac procedures

International Nuclear Information System (INIS)

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). (authors)

Active electronic personal dosemeter in interventional radiology

International Nuclear Information System (INIS)

Prlic, I.; Suric Mihic, M.; Vucic, Z.

2008-01-01

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)

Thermoluminescent dosimetry in veterinary diagnostic radiology

International Nuclear Information System (INIS)

Hernández-Ruiz, L.; Jimenez-Flores, Y.; Rivera-Montalvo, T.; Arias-Cisneros, L.; Méndez-Aguilar, R.E.; Uribe-Izquierdo, P.

2012-01-01

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.

Impact of climate changes on the Santos Harbor, São Paulo State (Brazil

Directory of Open Access Journals (Sweden)

Paolo Alfredini

2013-12-01

Full Text Available Santos Harbor Area (SHA in Sao Paulo Coastline (Brazil is the most important marine cargo transfer terminal in the Southern Hemisphere. A long term relative tidal level variability assessment shows a consistent response to relative sea level rise. A wave data base Wave Watch III was compared with a long term wave data-base generated by the ERA40-ECMWF (2003, both local validated. The current bed level of SHA Outer Channel is -15.00 m (Chart Datum or, in abbreviation, CD, maintained by dredging. According to the cargo throughput forecast, in 2025, the Access Channel will have to be deepened to level of -17.00 m. The feasibility of that choice is discussed from a technical, economical and conceptual navigation point of view in that context. A data set found from a scale model of the whole area of Santos Bay, Estuary and nearby beaches, showed the impact of maritime climate changes upon the coastal area. In the previous researches developed by the authors, it was demonstrated that the wave climate, the tides and tidal currents affect harbor and coastal structures maintenance, beaches stability, tidal inlet, sediment transport, saline intrusion and wetlands. Considering the increasing of the sea hazards and the high values of the infrastructures in that coastline, it is necessary to mitigate the risks. Hence, based on the results obtained by the authors, are highlighted guidelines strategies suggested for Access Channels dimensions, wharves free-board, jetties dimensions, dredging rates, rigid and flexible littoral defenses and land protection against flooding (including wetlands.

Morphology of nerve endings in vocal fold of human newborn.

Science.gov (United States)

Gonçalves da Silva Leite, Janaina; Costa Cavalcante, Maria Luzete; Fechine-Jamacaru, Francisco Vagnaldo; de Lima Pompeu, Margarida Maria; Leite, José Alberto Dias; Nascimento Coelho, Dulce Maria; Rabelo de Freitas, Marcos

2016-10-01

Sensory receptors are distributed throughout the oral cavity, pharynx, and larynx. Laryngeal sensitivity is crucial for maintaining safe swallowing, thus avoiding silent aspiration. Morphologic description of different receptor types present in larynx vary because of the study of many different species, from mouse to humans. The most commonly sensory structures described in laryngeal mucosa are free nerve endings, taste buds, muscle spindles, glomerular and corpuscular receptors. This study aimed at describing the morphology and the distribution of nerve endings in premature newborn glottic region. Transversal serial frozen sections of the whole vocal folds of three newborns were analyzed using an immuno-histochemical process with a pan-neuronal marker anti-protein gene product 9.5 (PGP 9.5). Imaging was done using a confocal laser microscope. Nerve fiber density in vocal cord was calculated using panoramic images in software Morphometric Analysis System v1.0. Some sensory structures, i.e. glomerular endings and intraepithelial free nerve endings were found in the vocal cord mucosa. Muscle spindles, complex nerve endings (Meissner-like, spherical, rectangular and growing) spiral-wharves nerve structures were identified in larynx intrinsic muscles. Nervous total mean density in vocal cord was similar in the three newborns, although they had different gestational age. The mean nerve fiber density was higher in the posterior region than anterior region of vocal cord. The present results demonstrate the occurrence of different morphotypes of sensory corpuscles and nerve endings premature newborn glottic region and provide information on their sensory systems. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Mapping surficial geology and assessment of permafrost conditions under the Iqaluit airport, Nunavut, Canada

Science.gov (United States)

Mathon-Dufour, V.; Allard, M.; Leblanc, A.; L'Hérault, E.; Oldenborger, G. A.; Sladen, W. E.

2012-12-01

Formerly, characterization of permafrost conditions was minimal before the construction of infrastructures. It was assumed that the permafrost would forever remain a solid substrate. Before global warming, transportation infrastructures were not designed, especially in terms of materials and dimensions, to withstand without damage an increased input of heat in the soil. Iqaluit airport, the hub of the eastern Canadian Arctic, is currently affected by thawing permafrost. In fact, the runway, taxiways and apron are affected by differential settlements resulting from the presence of localized ice-rich soils. This study uses a GIS approach that makes up for the absence of appropriate characterization before the construction of the airport during WWII and in the 1950s. Mapping of surficial geology, hydrography and landforms indicative of the presence of ground ice (e.g. tundra polygons) was produced by interpreting aerial photographs dating back from the initial phases of construction (1948) and photographs taken at intervals since then, to the most recent high-resolution satellite images. Subsequent map analysis shows that the original terrain conditions prevailing before the construction of the airport have a significant impact on the current stability of the infrastructure. Data integration allowed us to summarize the main problems affecting the Iqaluit airport which are: 1) Differential settlements associated with pre-construction drainage network 2) Cracking due to thermal contraction, 3) Linear depressions associated with ice wedge degradation and 4) Sink holes. Most of the sectors affected by differential settlements and instabilities are perfectly coincident with the original streams and lakes network that has been filled to increase the size of the runway, taxiways and the apron. In addition, the runway is affected by intense frost cracking. Similarities with nearby natural terrain suggest that the network pattern of the cracks follows pre-existing ice wedges

Thermochemical Concrete Pavement Scaling Mechanism: Navy F/A-18 Jet Aircraft Parking Apron Problem

Science.gov (United States)

1998-06-01

the phosphoric acid did originate from the phenyl orthophosphate and traces of red phosphorus used in the engine oil. It is suggested that engineers...b) bacterial degradation of the hexanoate and octanoate esters into the corresponding carboxylic acids. 3. The traces of calcium hydroxide known...orthophosphate and triphenyl phosphite were among these chemicals. These compounds help lubricate steel and reduce wear due to heat and friction. A

"Apron" flap and re-creation of the inframammary fold following TRAM flap breast reconstruction.

Science.gov (United States)

Amir, A; Silfen, R; Hauben, D J

2000-03-01

To the best of our knowledge, the recreation of an inframammary fold after TRAM flap breast reconstruction has not yet been described. This article offers a technique for the creation of an inframammary fold as a secondary procedure. The technique has been performed thus far in two patients with good aesthetic outcomes and no postoperative complications. It may also be suitable for adding bulk to the TRAM flap, especially in bilateral breast reconstruction, and for other minor chest deformities.

On-line sampling of apatite-nepheline ore using apron feeders by gamma-gamma method

Energy Technology Data Exchange (ETDEWEB)

Bliznyuk, G.I.

1981-01-01

The yield flow of an underground mine equipped with a crushing complex was investigated. /sup 241/Am source and 20x20 mm NaI(Tl) crystal were used; the lump size of apatite-nepheline ore was 200 mm, P/sub 2/O/sub 5/ content varied from 10 to 22%. The mean-square error was 1% P/sub 2/O/sub 5/ in 100-ton portions of mined ore. The method can be also applied for sampling iron, copper-nickel, and polymetallic ores.

Pseudotumors after primary abdominal lipectomy as a new sequela in patients with abdominal apron.

Science.gov (United States)

Dragu, Adrian; Bach, Alexander D; Polykandriotis, Elias; Kneser, Ulrich; Horch, Raymund E

2009-11-01

Malnutrition and overweight is a common problem in modern societies. Primary abdominal lipectomy is a standard surgical tool in patients with these problems. However, unknown secondary problems result from recent advances in obesity surgery. Plication of the anterior musculoaponeurotic wall is a widely and commonly used operative technique during abdominoplasty. Many different plication techniques have been published. So far no common standard and long-term effectiveness is proven. In addition, there is no sufficient literature dealing with the postoperative risks of plication of the musculoaponeurotic wall. Four patients with development of pseudotumors were reviewed. All four patients received 12 months in advance a primary abdominal lipectomy including a vertical plication of the musculoaponeurotic wall. All four patients were females with mean age of 61 years and mean body mass index (BMI) of 37 kg/m(2). All four patients had developed a pseudotumor of the abdomen as a long-term complication more than 12 months after primary abdominal lipectomy including a vertical plication of the anterior rectus sheath. One should be aware of the potential long-term risk of secondary postoperative hematoma formation, with or without partial necrosis of the anterior rectus sheath after vertical plication of the anterior musculoaponeurotic wall. Viewed clinically and radiologically, such sequelas may appear as pseudotumor like masses and require immediate revision.

Radiation exposure during ureteroscopy

International Nuclear Information System (INIS)

Bagley, D.H.; Cubler-Goodman, A.

1990-01-01

Use of fluoroscopy during ureteroscopy increases the risk of radiation exposure to the urologist and patient. Radiation entrance dosages were measured at skin level in 37 patients, and at the neck, trunk and finger of the urologist, and neck and trunk of the circulating nurse. Radiation exposure time was measured in 79 patients, and was related to the purpose of the procedure and the type of ureteroscope used, whether rigid or flexible. Exposure could be minimized by decreasing the fluoroscopy time. A portable C-arm fluoroscopy unit with electronic imaging and last image hold mode should be used to minimize exposure time. Lead aprons and thyroid shields should be used by the urologist and other personnel in the endoscopy room

Determination of effective dose for workers hemodynamics service using double dosimetry

International Nuclear Information System (INIS)

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.

2013-01-01

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)

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.

The level of radiation exposure of critical organs of the patient and the examiner during arteriographies

International Nuclear Information System (INIS)

Schmitt, G.; Lohr, E.; Ewen, K.

1979-01-01

The radiation exposures of the patient and the examiner during arteriographies are analyzed. The unshielded gonadal doses of the patient range from 1 mrem at brachial- and carotid arteriographies to 1000 mrem at pelvic arteriographies, while the bone marrow is exposed to approximately 500 mrem in the direct beam. For the examiner shielded by an apron with a lead equivalent of 0.25 mm, the body and gonadal doses do not exceed 10 mrem. The exposure of the eyes and the hands can reach 75 and 131 mrem, respectively. If skilful techniques and careful radiation protection are taken into account, genetic or somatic hazards are not to be expected for the patient and the examiner in the aforementioned dose range during arteriographies

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)

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

International Nuclear Information System (INIS)

Ishiguchi, T.; Nakamura, H.; Okazaki, M.

2000-01-01

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)

Utilizing borehole electrical images to interpret lithofacies of fan-delta: A case study of Lower Triassic Baikouquan Formation in Mahu Depression, Junggar Basin, China

Directory of Open Access Journals (Sweden)

Yuan Rui

2017-11-01

Full Text Available Large-scale conglomerate fan-delta aprons were typical deposits on the slope of Mahu Depression during the Early Triassic. Without outcrops, it is difficult to study the lithofacies only by examining the limited cores from the main oil-bearing interval of the Baikouquan Formation. Borehole electrical imaging log provides abundant high-resolution geologic information that is obtainable only from real rocks previously. Referring to the lithology and sedimentary structure of cores, a case study of fan-deltas in the Lower Triassic Baikouquan Formation of the Mahu Depression presents a methodology for interpreting the complicated lithofacies utilizing borehole electrical images. Eleven types of lithologies and five types of sedimentary structures are summarized in borehole electrical images. The sediments are fining upward from gravel to silt and clay in the Baikouquan Formation. Fine-pebbles and granules are the main deposits in T1b1 and T1b2, but sandstones, siltstones and mudstones are more developed in T1b3. The main sedimentary textures are massive beddings, cross beddings and scour-and-fill structures. Parallel and horizontal beddings are more developed in T1b3 relatively. On integrated analysis of the lithology and sedimentary structure, eight lithofacies from electrical images, referred to as image lithofacies, is established for the fan-deltas. Granules to coarse-pebbles within massive beddings, granules to coarse-pebbles within cross and parallel beddings, siltstones within horizontal and massive beddings are the most developed lithofacies respectively in T1b1, T1b2 and T1b3. It indicates a gradual rise of the lake level of Mahu depression during the Early Triassic, with the fan-delta aprons retrograding towards to the margin of the basin. Therefore, the borehole electrical imaging log compensate for the limitation of cores of the Baikouquan Formation, providing an effective new approach to interpret the lithofacies of fan-delta.

Fluoroscopic radiation exposure: are we protecting ourselves adequately?

Science.gov (United States)

Hoffler, C Edward; Ilyas, Asif M

2015-05-06

While traditional intraoperative fluoroscopy protection relies on thyroid shields and aprons, recent data suggest that the surgeon's eyes and hands receive more exposure than previously appreciated. Using a distal radial fracture surgery model, we examined (1) radiation exposure to the eyes, thyroid, chest, groin, and hands of a surgeon mannequin; (2) the degree to which shielding equipment can decrease exposure; and (3) how exposure varies with fluoroscopy unit size. An anthropomorphic model was fit with radiation-attenuating glasses, a thyroid shield, an apron, and gloves. "Exposed" thermoluminescent dosimeters overlaid the protective equipment at the eyes, thyroid, chest, groin, and index finger while "shielded" dosimeters were placed beneath the protective equipment. Fluoroscopy position and settings were standardized. The mini-c-arm milliampere-seconds were fixed based on the selection of the kilovolt peak (kVp). Three mini and three standard c-arms scanned a model of the patient's wrist continuously for fifteen minutes each. Ten dosimeter exposures were recorded for each c-arm. Hand exposure averaged 31 μSv/min (range, 22 to 48 μSv/min), which was 13.0 times higher than the other recorded exposures. Eye exposure averaged 4 μSv/min, 2.2 times higher than the mean thyroid, chest, and groin exposure. Gloves reduced hand exposure by 69.4%. Glasses decreased eye exposure by 65.6%. There was no significant difference in exposure between mini and standard fluoroscopy. Surgeons' hands receive the most radiation exposure during distal radial plate fixation under fluoroscopy. There was a small but insignificant difference in mean exposure between standard fluoroscopy and mini-fluoroscopy, but some standard units resulted in lower exposure than some mini-units. On the basis of these findings, we recommend routine protective equipment to mitigate exposure to surgeons' hands and eyes, in addition to the thyroid, chest, and groin, during fluoroscopy procedures

Utilizing borehole electrical images to interpret lithofacies of fan-delta: A case study of Lower Triassic Baikouquan Formation in Mahu Depression, Junggar Basin, China

Science.gov (United States)

Yuan, Rui; Zhang, Changmin; Tang, Yong; Qu, Jianhua; Guo, Xudong; Sun, Yuqiu; Zhu, Rui; Zhou, Yuanquan (Nancy)

2017-11-01

Large-scale conglomerate fan-delta aprons were typical deposits on the slope of Mahu Depression during the Early Triassic. Without outcrops, it is difficult to study the lithofacies only by examining the limited cores from the main oil-bearing interval of the Baikouquan Formation. Borehole electrical imaging log provides abundant high-resolution geologic information that is obtainable only from real rocks previously. Referring to the lithology and sedimentary structure of cores, a case study of fan-deltas in the Lower Triassic Baikouquan Formation of the Mahu Depression presents a methodology for interpreting the complicated lithofacies utilizing borehole electrical images. Eleven types of lithologies and five types of sedimentary structures are summarized in borehole electrical images. The sediments are fining upward from gravel to silt and clay in the Baikouquan Formation. Fine-pebbles and granules are the main deposits in T1b1 and T1b2, but sandstones, siltstones and mudstones are more developed in T1b3. The main sedimentary textures are massive beddings, cross beddings and scour-and-fill structures. Parallel and horizontal beddings are more developed in T1b3 relatively. On integrated analysis of the lithology and sedimentary structure, eight lithofacies from electrical images, referred to as image lithofacies, is established for the fan-deltas. Granules to coarse-pebbles within massive beddings, granules to coarse-pebbles within cross and parallel beddings, siltstones within horizontal and massive beddings are the most developed lithofacies respectively in T1b1, T1b2 and T1b3. It indicates a gradual rise of the lake level of Mahu depression during the Early Triassic, with the fan-delta aprons retrograding towards to the margin of the basin. Therefore, the borehole electrical imaging log compensate for the limitation of cores of the Baikouquan Formation, providing an effective new approach to interpret the lithofacies of fan-delta.

Antecedent topography and morphological controls on sediment accumulation and slope stability of the U.S. Atlantic margin

Science.gov (United States)

Hill, J. C.; Brothers, D. S.; Ten Brink, U. S.; Andrews, B. D.

2017-12-01

The U.S. Atlantic margin encompasses a wide variety of slope failure processes, ranging from small canyon-confined failures on the upper slope to large, open slope landslides originating in deeper water. Here we used a suite of high-resolution multibeam bathymetry and detailed multichannel seismic data coverage to investigate the relationship between modern seafloor morphology, pre-existing stratigraphy and sediment accumulation patterns. We suggest that a combination of sediment supply and antecedent margin physiography, whereby variations in margin evolution during the Miocene have influenced the modern seafloor morphology, controls both the location of slope sediment accumulation and the style of slope failure. Oversteepened margins with angular shelf breaks and steep upper slopes, referred to as oblique margins, are characterized by downslope mass transport and densely-spaced canyon formation. These margins are most likely the locus of canyon-confined failures and smaller lower slope fan-apron failures (e.g., much of the Mid-Atlantic). Sigmoidal margins with prograded slopes, a rounded shelf edge, and a low gradient slope morphology can support significant sediment accumulation across a broad area, with limited canyon development. These margins are often associated with high sediment supply and are prone to large, upper slope slab-style failures (e.g., the Hudson Apron, southwestern New England, the Currituck and Cape Fear Slide complexes). Areas with morphologies in between these two end members are characterized by limited shelf-edge accommodation space and large-scale lower slope accumulation and onlap, representing transitional stages of equilibrium slope adjustment. Large failures along these intermediate-type margins tend to develop lower on the slope where thick wedges of onlapping sediment are found (e.g., around Washington Canyon, Cape Lookout and southeastern New England). As antecedent topography and sediment loading appear to play an important role

Task-specific monitoring of nuclear medicine technologists' radiation exposure

International Nuclear Information System (INIS)

Smart, R.

2004-01-01

Many studies have demonstrated that the exposure of nuclear medicine technologists arises primarily from radioactive patients rather than from preparation of radiopharmaceuticals. However, in order to devise strategies to reduce staff exposure, it is necessary to identify the specific tasks within each procedure that result in the highest radiation doses. An ESM Eberline FH41B-10 radiation dosemeter, which records the ambient dose equivalent rate, was used to monitor the radiation exposure of a technologist and to record the dose rate in μSv per hour every 32 s throughout a working day. The technologist recorded the procedures that were being performed so that the procedures that resulted in higher doses could be identified clearly. The measured doses clearly showed that the major contributions to the technologist's dose were the following: (1) transferring incapacitated patients from the imaging table to a hospital trolley; (2) difficult injections without syringe shields; and (3) setting up patients for gated myocardial scans. The average dose to the technologist from transferring patients after a bone scan was 0.54 μSv, 40% of the total dose of 1.3 μSv for the complete bone scan procedure. The average dose received injecting 900 MBq of 99 Tc m -HDP using a tungsten syringe shield was 0.57 μSv, but the highest dose was 1.6 μSv, in a patient in whom the injection was difficult. A 0.5 mm lead apron was found to reduce the dose when setting up a patient for a gated stress 99 Tc m -sestamibi myocardial scan by approximately a factor of 2. The average dose per patient for this task was reduced from 1.1 to 0.6 μSv. It is recommended that staff waiting for assistance with patient transfers stand away from the patient, that tungsten syringe shields be used for all radiopharmaceutical injections and that a 0.5 mm lead apron be worn when attending patients containing high activities of 99 Tc m radiopharmaceuticals, such as those having myocardial imaging. (authors)

Micro-/nano-characterization of the surface structures on the divertor tiles from JET ITER-like wall

Energy Technology Data Exchange (ETDEWEB)

Tokitani, M., E-mail: tokitani.masayuki@LHD.nifs.ac.jp [National Institute for Fusion Science, Oroshi, Toki, Gifu 509-5292 (Japan); Miyamoto, M. [Shimane University, Matsue, Shimane 690-8504 (Japan); Masuzaki, S. [National Institute for Fusion Science, Oroshi, Toki, Gifu 509-5292 (Japan); Fujii, Y. [Shimane University, Matsue, Shimane 690-8504 (Japan); Sakamoto, R. [National Institute for Fusion Science, Oroshi, Toki, Gifu 509-5292 (Japan); Oya, Y. [Shizuoka University, Shizuoka 422-8529 (Japan); Hatano, Y. [University of Toyama, Toyama 930-8555 (Japan); Otsuka, T. [Kindai University, Higashi-Osaka, Osaka, 577-8502 (Japan); Oyaidzu, M.; Kurotaki, H.; Suzuki, T.; Hamaguchi, D.; Isobe, K.; Asakura, N. [National Institute for Quantum and Radiological Science and Technology (QST), Rokkasho Aomori 039-3212 (Japan); Widdowson, A. [EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Rubel, M. [Royal Institute of Technology (KTH), 100 44 Stockholm (Sweden)

2017-03-15

Highlights: • Micro-/nano-characterization of the surface structures on the divertor tiles from JET ITER-like wall were studied. • The stratified mixed-material deposition layer composed by W, C, O, Mo and Be with the thickness of ∼1.5 μm was formed on the apron of Tile 1. • The study revealed the micro- and nano-scale modification of the inner tile surface of the JET ILW. - Abstract: Micro-/nano-characterization of the surface structures on the divertor tiles used in the first campaign (2011–2012) of the JET tokamak with the ITER-like wall (JET ILW) were studied. The analyzed tiles were a single poloidal section of the tile numbers of 1, 3 and 4, i.e., upper, vertical and horizontal targets, respectively. A sample from the apron of Tile 1 was deposition-dominated. Stratified mixed-material layers composed of Be, W, Ni, O and C were deposited on the original W-coating. Their total thickness was ∼1.5 μm. By means of transmission electron microscopy, nano-size bubble-like structures with a size of more than 100 nm were identified in that layer. They could be related to deuterium retention in the layer dominated by Be. The surface microstructure of the sample from Tile 4 also showed deposition: a stratified mixed-material layer with the total thickness of 200–300 nm. The electron diffraction pattern obtained with transmission electron microscope indicated Be was included in the layer. No bubble-like structures have been identified. The surface of Tile 3, originally coated by Mo, was identified as the erosion zone. This is consistent with the fact that the strike point was often located on that tile during the plasma operation. The study revealed the micro- and nano-scale modification of the inner tile surface of the JET ILW. In particular, a complex mixed-material deposition layer could affect hydrogen isotope retention and dust formation.

Endoscopy dose examinations at the Sao Paulo University Hospital

International Nuclear Information System (INIS)

Aldred, M.A.; Siqueira P, W.; Fonseca F, A.M. da; Nucci, J.R.; Yoshimura, E. M.; Okuno, E.

1996-01-01

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

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

The stratigraphy of successions exposed in footwall crests of tilted fault blocks is commonly highly complex. Crestal stratigraphy and structure are particularly difficult to unravel in the subsurface due to poor seismic resolution across fault zones, footwall collapse, and coalescing syn- and post......-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...

Radiation dose electrophysiology procedures

International Nuclear Information System (INIS)

Hernandez-Armas, J.; Rodriguez, A.; Catalan, A.; Hernandez Armas, O.; Luque Japon, L.; Moral, S.; Barroso, L.; Rfuez-Hdez, R.

2006-01-01

The aim of this paper has been to measure and analyse some of the parameters which are directly related with the doses given to patients in two electrophysiology procedures: diagnosis and ablation with radiofrequency. 16 patients were considered in this study. 13 them had an ablation with radiofrequency at the Unit of Electrophysiology at the University Hospital of the Canaries, La Laguna., Tenerife. The results of skin doses, in the ablation cases, were higher than 2 Gy (threshold of some deterministic effects). The average value was 1.1 Gy. The personal doses, measured under the lead apron, for physician and nurses were 4 and 3 micro Sievert. These results emphasised the necessity of radiation protection measures in order to reduce, ad much as possible, the doses to patients. (Author)

Seismoturbidite record as preserved at core sites at the Cascadia and Sumatra–Andaman subduction zones

Directory of Open Access Journals (Sweden)

J. R. Patton

2013-04-01

Full Text Available Turbidite deposition along slope and trench settings is evaluated for the Cascadia and Sumatra–Andaman subduction zones. Source proximity, basin effects, turbidity current flow path, temporal and spatial earthquake rupture, hydrodynamics, and topography all likely play roles in the deposition of the turbidites as evidenced by the vertical structure of the final deposits. Channel systems tend to promote low-frequency components of the content of the current over longer distances, while more proximal slope basins and base-of-slope apron fan settings result in a turbidite structure that is likely influenced by local physiography and other factors. Cascadia's margin is dominated by glacial cycle constructed pathways which promote turbidity current flows for large distances. Sumatra margin pathways do not inherit these antecedent sedimentary systems, so turbidity currents are more localized.

USBR Type III and Type IV stilling basin and rock apron associated with stepped chutes

Science.gov (United States)

Stilling basins are commonly used as energy dissipators for structural chutes. Classical research conducted by scientists of the U. S. Bureau of Reclamation (USBR) led to the development of design criteria for a variety of stilling basin configurations as the outlet works for smooth chutes, but lit...

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…

The Institutionalization of Photojournalism Education: Bringing the Blue-Apron Ghetto to American Schools of Journalism

Science.gov (United States)

Paddock, Stanton M.

2017-01-01

As journalism educators wrestle to keep programs up-to-date in an evolving news landscape, there is value in understanding how education in an early form of multimedia journalism--photography--came to be. Little attention has been paid to the intersection of journalism education and photojournalism. This subject furnishes a unique perspective on…

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

International Nuclear Information System (INIS)

Falivene, A.; Gori, C.; Mazzocchi, S.; Targetti, S.; Zatelli, G.

2002-01-01

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 9 9mT c 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

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

DEFF Research Database (Denmark)

Møller, Karina Lauenborg; Thygesen, Lau Caspar; Schipperijn, Jasper

2014-01-01

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...

X-ray screening materials

International Nuclear Information System (INIS)

Wardley, R.B.

1981-01-01

This invention relates to x-ray screening materials and especially to materials in sheet form for use in the production of, for example, protective clothing such as aprons and lower back shields, curtains, mobile screens and suspended shields. The invention is based on the observation that x-ray screening materials in sheet form having greater flexiblity than the hitherto known x-ray screening materials of the same x-ray absorber content can be produced if, instead of using a single sheet of filled sheet material of increased thickness, one uses a plurality of sheets of lesser thickness together forming a laminar material of the desired thickness and one bonds the individual sheets together at their edges and, optionally, at other spaced apart points away from the edges thereby allowing one sheet to move relative to another. (U.K.)

Climate change and coasts

International Nuclear Information System (INIS)

Schellnhuber, H.J.; Sterr, H.

1993-01-01

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 [de

The colossal task of Ouranos

International Nuclear Information System (INIS)

Grondin, N.

2003-01-01

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

Geologic Map of MTM 35337, 40337, and 45337 Quadrangles, Deuteronilus Mensae Region of Mars

Science.gov (United States)

Chuang, Frank C.; Crown, David A.

2009-01-01

Deuteronilus Mensae, first defined as an albedo feature at lat 35.0 deg N., long 5.0 deg E., by U.S. Geological Survey (USGS) and International Astronomical Union (IAU) nomenclature, is a gradational zone along the dichotomy boundary in the northern mid-latitudes of Mars. The boundary in this location includes the transition from the rugged cratered highlands of Arabia Terra to the northern lowland plains of Acidalia Planitia. Within Deuteronilus Mensae, polygonal mesas are prominent along with features diagnostic of Martian fretted terrain, including lobate debris aprons, lineated valley fill, and concentric crater fill. Lobate debris aprons, as well as the valley and crater fill deposits, are geomorphic indicators of ground ice, and their concentration in Deuteronilus Mensae is of great interest because of their potential association with Martian climate change. The paucity of impact craters on the surfaces of debris aprons and the presence of ice-cemented mantle material imply young (for example, Amazonian) surface ages that are consistent with recent climate change in this region of Mars. North of Deuteronilus Mensae are the northern lowlands, a potential depositional sink that may have had large standing bodies of water or an ocean in the past. The northern lowlands have elevations that are several kilometers below the ancient cratered highlands with significantly younger surface ages. The morphologic and topographic characteristics of the Deuteronilus Mensae region record a diverse geologic history, including significant modification of the ancient highland plateau and resurfacing of low-lying regions. Previous studies of this region have interpreted a complex array of geologic processes, including eolian, fluvial and glacial activity, coastal erosion, marine deposition, mass wasting, tectonic faulting, effusive volcanism, and hydrovolcanism. The origin and age of the Martian crustal dichotomy boundary are fundamental questions that remain unresolved at the

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)

Jacob, S.; Bertrand, A.; Laurier, D.; Bernier, M.O.; Scanff, P.

2014-01-01

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

Survey of radiologic practices among dental practitioners

International Nuclear Information System (INIS)

Goren, A.D.; Sciubba, J.J.; Friedman, R.; Malamud, H.

1989-01-01

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

300 Area Process Trenches Verification Package

International Nuclear Information System (INIS)

Lerch, J.A.

1998-03-01

The purpose of this verification package is to document achievement of the remedial action objectives for the 300 Area Process Trenches (300 APT) located within the 300-FF-1 Operable Unit (OU). The 300 APT became active in 1975 as a replacement for the North and South Process Pond system that is also part of the 300-FF-1 OU. The trenches received 300 Area process effluent from the uranium fuel fabrication facilities. Waste from the 300 Area laboratories that was determined to be below discharge limits based on monitoring performed at the 307 retention basin was also released to the trenches. Effluent flowed through the headworks sluice gates, down a concrete apron, and into the trenches. From the beginning of operations in 1975 until 1993, a continuous, composite sampler was located at the headwork structure to analyze process effluent at the point of discharge to the environment

Radiation doses for X-ray diagnosis teeth in dental medicine

International Nuclear Information System (INIS)

Direkov, Lyubomir

2009-01-01

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

Tectonic and sedimentological environments of sandstone-hosted uranium deposits, with special reference to the Karoo Basin of South Africa

International Nuclear Information System (INIS)

Le Roux, J.P.

1985-01-01

The principal tectonic and sedimentological settings for sandstone-hosted uranium deposits are described. Back-arc basins filled with post-Silurian, fluvial sediments bordering subduction zone magmatic arcs of calc-alkaline composition are considered favourable tectonic environments. The basins should be closed to prevent excessive oxidation of the sediments. Uranium deposits are concentrated near basin rims in the transition zone between uplift and basin subsidence, because of favourable sedimentary facies in those areas. Syn- and post-depositional deformation could have affected the localisation of uranium ore-bodies, while intrusive centres or uplifted arcs commonly have surrounding aprons of potential host rocks. Stratigraphic zoning is also related to source area tectonics and can be used to predict favourable sedimentary environments. Sedimentological processes had a direct influence on the permeability and carbonaceous matter content of sandstones and therefore have often controlled the localisation of ore-bodies. (author)

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

International Nuclear Information System (INIS)

Chougle, Arun

1993-01-01

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 CaSO 4 :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

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

International Nuclear Information System (INIS)

Komemushi, Atsushi; Tanigawa, Noboru; Aoki, Atsuko

2010-01-01

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)

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

deposits occur in Belize and southern Mexico where the so called Albion island spheroid bed is superimposed on the target rock (the Barton Creek Formation). We analysed the spheroid bed via Mössbauer spectroscopy, petrology, XRD, and palynology at several sites ~ 350-500 km distance from the crater centre....... Our results show that the relative concentrations of Fe in nano-phase goethite (α-FeOOH) are very high in the spheroid bed samples from Albion Island (Belize) and from Ramonal South (Mexico), but are low to absent in the spheroid bed at Ramonal North, and in the Cretaceous target rock. Moreover, our......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...

[Radiation protection in interventional radiology].

Science.gov (United States)

Adamus, R; Loose, R; Wucherer, M; Uder, M; Galster, M

2016-03-01

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.

Lift-up construction method of apron pavement in the airport. Kuko epuron hoso no lift up koho

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, H. (Ministry of Transport, Tokyo (Japan))

1994-03-25

Frequently used airports do not allow the period during which facilities are shutdown for cultivation in the repair work of sunk concrete pavement. The present report describes the outline of the lift-up construction method by means of prestressed concrete pavement which allows repair work only in the night. The method has been developed and demonstrated this time in the construction of off-shore development of Tokyo International Airport. The fundamental procedures are as follows: A [phi] 16cm hole is drilled with a core boring machine into the pavement slab in the sunk area; the roadbed is excavated around the hole in the volume of ca. 45cm in diameter and ca. 30cm in thickness; a reaction bed of concrete and a metal fixture of the hydraulic jack are installed; the reaction bed is exerted with a force by the jack to lift up the pavement slab; and finally the gap made between the pavement slab and the road bed is grouted with cement milk. In a demonstration test construction, lift-up of 3.5cm over ca. 3500m[sup 2] was performed during a total of four days of one day in the daytime and three days in the night. 7 figs.

A study of the behaviour of and the forces in a bed protecting mattress : The falling apron

NARCIS (Netherlands)

Vrijling, J.K.; Ravenstijn, P.

2001-01-01

In many cases the bottom around a structure that is exposed to current has to be protected by a mattress. The purpose of the mattress is to protect the soil besides the structure from erosion and scour, thus preserving the strength of the foundation of the structure. Examples are the bottom

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

International Nuclear Information System (INIS)

Santos, Lucas R. dos; Oliveira, Celso A.; Silva, Fabio A.R.; Souza, Divanizia N.

2008-01-01

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)

Occupational dose assessment in interventional cardiology in Serbia

International Nuclear Information System (INIS)

Kaljevic, J.; Ciraj-Bjelac, O.; Stankovic, J.; Arandjic, D.; Bozovic, P.; Antic, V.

2016-01-01

The objective of this work is to assess the occupational dose in interventional cardiology in a large hospital in Belgrade, Serbia. A double-dosimetry method was applied for the estimation of whole-body dose, using thermoluminescent dosemeters, calibrated in terms of the personal dose equivalent H p (10). Besides the double-dosimetry method, eye dose was also estimated by means of measuring ambient dose equivalent, H*(10), and doses per procedure were reported. Doses were assessed for 13 physicians, 6 nurses and 10 radiographers, for 2 consequent years. The maximum annual effective dose assessed was 4.3, 2.1 and 1.3 mSv for physicians, nurses and radiographers, respectively. The maximum doses recorded by the dosemeter worn at the collar level (over the apron) were 16.8, 11.9 and 4.5 mSv, respectively. This value was used for the eye lens dose assessment. Estimated doses are in accordance with or higher than annual dose limits for the occupational exposure. (authors)

Use of active dosimeters as tool for optimization in hemodynamics; Uso de dosimetros ativos como ferramenta de otimizacao em hemodinamica

Energy Technology Data Exchange (ETDEWEB)

Nunes, Rafael; Pereira, Dirceu D., E-mail: rafael@bolsista.ird.gov.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Fisica; Canevaro, Lucia V. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Rodrigues, Barbara B.D. [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Ferreira, Esmeralci [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Faculdade de Medicina. Servico de Hemodinamica

2016-07-01

Interventional cardiology procedures are, in general, associated with high doses to patients and professionals. The objective of this study is to measure the radiation levels received by the staff. The professional dosimetry was performed in a department of Hemodynamics of University Hospital in Rio de Janeiro, were followed 331 coronary angiography (CA) and 26 percutaneous transluminal coronary angioplasty (PTCA) procedures. In order to measure the radiation levels at the chest of interventional professionals outside of lead aprons, active dosemeters were used. The results show that average personal equivalent dose of doctors, per procedure was 100μSv e 154 μSv. On average, nursing technicians and radiographers receive 12% and 10% of doses of physicians, respectively, during CA and PTCA procedures. From the results, it appears that the doses of hemodynamicists could exceed the annual dose limit of the standards, if radiological protection conduct would not be applied. The use of lead shielding has showed as an effective action to reduce doses in these workers. (author)

UTILIZAÇÃO DOS DEPÓSITOS DE ENCOSTAS DOS BREJOS PERNAMBUCANOS COMO MARCADORES PALEOCLIMÁTICOS DO QUATERNÁRIO TARDIO NO SEMI-ÁRIDO NORDESTINO

Directory of Open Access Journals (Sweden)

Antônio Carlos de Barros Corrêa

2008-01-01

Full Text Available The assessment of the geomorphological dynamics of ecologically discontinuous areas in the elevated compartments of Borborema Highlands has prioritized the occurrence of datable sedimentary deposits, which have been identified following a qualitative surveying of geomorphological features. The chosen pilot-areas for the conduction of this research were the Baixa Verde massif and the highlands of Brejo da Madre de Deus, State of Pernambuco. Among the several identified features, hill slope deposits, colluvium, in the shape of ramps and aprons were chosen for reconstructing the geomorphological dynamics. The stratigraphy of materials that overlie the surface of the landscape was defined following the elaboration of log sections. Optically stimulated luminescence dating of sediments was used as a tool for the qualitative reconstruction of depositional events and establishing models for landforms evolution. The obtained results indicated the occurrence of discrete events of material remobilization along the slopes as a response to climatic oscillations following the last glacial maximum.

Prediction of scour caused by 2D horizontal jets using soft computing techniques

Directory of Open Access Journals (Sweden)

Masoud Karbasi

2017-12-01

Full Text Available This paper presents application of five soft-computing techniques, artificial neural networks, support vector regression, gene expression programming, grouping method of data handling (GMDH neural network and adaptive-network-based fuzzy inference system, to predict maximum scour hole depth downstream of a sluice gate. The input parameters affecting the scour depth are the sediment size and its gradation, apron length, sluice gate opening, jet Froude number and the tail water depth. Six non-dimensional parameters were achieved to define a functional relationship between the input and output variables. Published data were used from the experimental researches. The results of soft-computing techniques were compared with empirical and regression based equations. The results obtained from the soft-computing techniques are superior to those of empirical and regression based equations. Comparison of soft-computing techniques showed that accuracy of the ANN model is higher than other models (RMSE = 0.869. A new GEP based equation was proposed.

Technique-dependent decrease in thyroid absorbed dose for dental radiography

International Nuclear Information System (INIS)

Wood, R.E.; Bristow, R.G.; Clark, G.M.; Nussbaum, C.; Taylor, K.W.

1989-01-01

A LiF thermoluminescent dosimetry (TLD) system, calibrated in the tissue of interest with the beam used for experimentation, was employed to investigate dosages (muGy) to the thyroid region of an anthropomorphic phantom resultant from two dental complete-mouth radiographic procedures. Both techniques were compared in terms of dosages associated with combinations of lead apron and thyroid collar shielding while using a 70-kVp or 90-kVp x-ray beam for a 20-film complete-mouth series. Lead shielding significantly decreased the dose to the thyroid using both techniques (p less than 0.05). The use of the 90-kVp beam resulted in a significant reduction in the thyroid absorbed dose when using the bisecting angle technique (p less than 0.05) but caused a significant increase in the thyroid absorbed dose when the paralleling technique was used (p less than 0.05). The implementation of higher kilovoltage techniques in dental offices must therefore be dependent on the radiographic technique employed

Fine-Scale Layering of Mars Polar Deposits and Signatures of Ice Content in Nonpolar Material From Multiband SHARAD Data Processing

Science.gov (United States)

Campbell, Bruce A.; Morgan, Gareth A.

2018-02-01

The variation of Shallow Radar (SHARAD) echo strength with frequency reveals material dielectric losses and polar layer properties. Loss tangents for Elysium and Amazonis Planitiae deposits are consistent with volcanic flows and sediments, while the Medusae Fossae Formation, lineated valley fill, and lobate debris aprons have low losses consistent with a major component of water ice. Mantling materials in Arcadia and Utopia Planitiae have higher losses, suggesting they are not dominated by ice over large fractions of their thickness. In Gemina Lingula, there are frequent deviations from a simple dependence of loss on depth. Within reflector packets, the brightest reflectors are often different among the frequency subbands, and there are cases of reflectors that occur in only the high- or low-frequency echoes. Many polar radar reflections must arise from multiple thin interfaces, or single deposits of appropriate thickness, that display resonant scattering behaviors. Reflector properties may be linked to climate-controlled polar dust deposition.

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.

On-field evaluation of operator lens protective devices in interventional radiology

International Nuclear Information System (INIS)

Strocchi, S.; Chiaravalli, A.; Veronese, I.; Novario, R.

2016-01-01

The recent publication of the Euratom Directive 2013/59, adopting the reduction of eye lens dose limits from 150 to 20 mSv y"-"1, calls for the development of new tools and methodologies for evaluating the eye lens dose absorbed by the medical staff involved in interventional radiology practices. Moreover, the effectiveness of the protective devices, like leaded glasses, which can be employed for radiation protection purposes, must be tested under typical exposure scenarios. In this work, eye lens dose measurements were carried out on an anthropomorphic phantom simulating a physician bound to perform standard interventional neuroradiology angiographic procedures. The correlation between eye lens doses, in terms of Hp(0.07), and the equivalent dose [again in terms of Hp(0.07)] monthly measured with thermoluminescent dosemeters placed above the lead apron at the chest level was studied, in the presence and in the absence of different types of leaded glasses. (authors)

Work procedures and risk factors for high rdiation exposure among radiologic technologists in South Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Young; Choi, Yeong Chull [Dept. of Preventive Medicine, Keimyung University College of Medicine, Daegu (Korea, Republic of); Lee, Won Jin; Cha, Eun Shil [Dept. of Preventive Medicine, Korea University College of Medicine, Seoul (Korea, Republic of)

2016-12-15

Radiologic technologists currently consist of 31.5% among diagnostic radiation workers in South Korea. Among diagnostic radiation workers, radiologic technologists receive the highest annual and collective doses in South Korea. Comprehensive assessment of the work practices and associated radiation doses from diagnostic radiology procedures should be undertaken for effective prevention for radiologic technologists. Using the national survey, this study aimed (1) to explore the distribution of the work procedures performed by gender, (2) to evaluate occupational radiation exposure by work characteristics and safety compliance, (3) to identify the primary factors influencing high radiation exposure among radiologic technologists in South Korea. This study provided detailed information on work practices, number of procedures performed on weekly basis, and occupational radiation doses among radiologic technologists in South Korea. Average radiation dose for radiologic technologists is higher than other countries, and type of facility, work safety, and wearing lead apron explained quite a portion of increased risk in the association between radiology procedures and radiation exposure among radiologic technologists.

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.

Coarse to fine aircraft detection from front-looking infrared images

Science.gov (United States)

Lin, Jin; Tan, Yihua; Tian, Jinwen

2018-03-01

Due to the weak feature and wide angle of long-distance aircraft targeting in the parking apron from front-looking infrared images, there are always false alarms in aircraft targeting detection. This leads to relatively poor reliability for detection results. In this paper, we present a scene-driven coarse-to-fine aircraft target detection method. First, we preprocess the image by combining the sharpened and enhanced images. Second, the region of interest (ROI) is segmented by using the local mean variance of the image and a series of subsequent processing. Then, target candidate areas are located by using the feature of local marginal distributions. Lastly, aircrafts can be detected accurately by a novel aircraft shape filter. Experiments on three infrared image sequences have shown that the presented method is effective and robust in detecting long-distance aircraft from front-looking infrared images and can also improve the reliability of the detection results.

Radiologist and angiographic procedures. Absorbed radiation dose

International Nuclear Information System (INIS)

Tryhus, M.; Mettler, F.A. Jr.; Kelsey, C.

1987-01-01

The radiation dose absorbed by the angiographer during angiographic procedures is of vital importance to the radiologist. Nevertheless, most articles on the subject are incomplete, and few measure gonadal dose. In this study, three TLDs were used for each of the following sites: radiologist's eyes, thyroid, gonads with and without shielding apron, and hands. The average dose during carotid angiograms was 2.6, 4.1, 0.4, 4.7, and 7.1 mrads to the eyes, thyroid, gonads with and without .5 mm of lead shielding, and hands, respectively. Average dose during abdominal and peripheral vascular angiographic procedures was 5.2, 7.5, 1.2, 8.5, and 39.9 mrads to the eyes, thyroid, gonads with and without shielding, and hands, respectively. A literature review demonstrates a significant reduction in radiation dose to the angiographer after the advent of automated injectors. Our measured doses for carotid angiography are compatible with contemporary reported values. There was poor correlation with fluoroscopy time and measured dose to the angiographer

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

International Nuclear Information System (INIS)

Rossi, Pier Luca; Bianchini, David; Corazza, Ivan; Compagnone, Gaetano; Ferrari, Paolo; Gualdrini, Gianfranco; Zannoli, Romano

2011-01-01

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 H p (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 H p (10) data that can be used to estimate the risk for the electrophysiologist performing this procedure.

Analyses of microstructure, composition and retention of hydrogen isotopes in divertor tiles of JET with the ITER-like wall

Science.gov (United States)

Masuzaki, S.; Tokitani, M.; Otsuka, T.; Oya, Y.; Hatano, Y.; Miyamoto, M.; Sakamoto, R.; Ashikawa, N.; Sakurada, S.; Uemura, Y.; Azuma, K.; Yumizuru, K.; Oyaizu, M.; Suzuki, T.; Kurotaki, H.; Hamaguchi, D.; Isobe, K.; Asakura, N.; Widdowson, A.; Heinola, K.; Jachmich, S.; Rubel, M.; contributors, JET

2017-12-01

Results of the comprehensive surface analyses of divertor tiles and dusts retrieved from JET after the first ITER-like wall campaign (2011-2012) are presented. The samples cored from the divertor tiles were analyzed. Numerous nano-size bubble-like structures were observed in the deposition layer on the apron of the inner divertor tile, and a beryllium dust with the same structures were found in the matter collected from the inner divertor after the campaign. This suggests that the nano-size bubble-like structures can make the deposition layer to become brittle and may lead to cracking followed by dust generation. X-ray photoelectron spectroscopy analyses of chemical states of species in the deposition layers identified the formation of beryllium-tungsten intermetallic compounds on an inner vertical tile. Different tritium retention profiles along the divertor tiles were observed at the top surfaces and at deeper regions of the tiles by using the imaging plate technique.

Conditions of radiation protection in medical stations

International Nuclear Information System (INIS)

Sa, L.R.B.S.; Tomaz Neto, A.; Pires, A.; Azevedo, H.; Boasquevisque, E.M.

1988-01-01

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) [pt

Work procedures and risk factors for high rdiation exposure among radiologic technologists in South Korea

International Nuclear Information System (INIS)

Kim, Jae Young; Choi, Yeong Chull; Lee, Won Jin; Cha, Eun Shil

2016-01-01

Radiologic technologists currently consist of 31.5% among diagnostic radiation workers in South Korea. Among diagnostic radiation workers, radiologic technologists receive the highest annual and collective doses in South Korea. Comprehensive assessment of the work practices and associated radiation doses from diagnostic radiology procedures should be undertaken for effective prevention for radiologic technologists. Using the national survey, this study aimed (1) to explore the distribution of the work procedures performed by gender, (2) to evaluate occupational radiation exposure by work characteristics and safety compliance, (3) to identify the primary factors influencing high radiation exposure among radiologic technologists in South Korea. This study provided detailed information on work practices, number of procedures performed on weekly basis, and occupational radiation doses among radiologic technologists in South Korea. Average radiation dose for radiologic technologists is higher than other countries, and type of facility, work safety, and wearing lead apron explained quite a portion of increased risk in the association between radiology procedures and radiation exposure among radiologic technologists.

Regional stratigraphy, sedimentology, and tectonic significance of Oligocene-Miocene sedimentary and volcanic rocks, northern Baja California, Mexico

Science.gov (United States)

Dorsey, Rebecca J.; Burns, Beverly

1994-01-01

Upper Oligocene (?) to middle Miocene sedimentary and volcanic rocks in northern Baja California were deposited along the western margin of North America during subduction of the Guadalupe plate and southward migration of the Rivera Triple Junction. Regional mapping and compilation of stratigraphic data reveal a sequence of three regionally traceable stratigraphic units. (1) Oligocene (?) to lower Miocene Mesa Formation: basal quartz-rich fluvial sandstone, grus, conglomerate, and accessory facies, whose detrital compositions reflect the composition of local pre-Tertiary basement rock. (2) Lower to middle Miocene Comondú Formation: laterally variable sequence of volcaniclastic conglomerate, breccia, sandstone, tuff and minor volcanic flow units. (3) Widespread mesa-capping rhyolite tuff, typically welded and crystal-rich, probably upper Miocene in age. The Mesa Formation overlies a highly irregular and deeply dissected erosional surface developed on pre-Tertiary basement rock. The shift from pre-Mesa erosion to widespread (though localized) deposition and valley-filling records the final phase of late Cretaceous to middle Tertiary regional subsidence and eastward transgression that resulted from slow cooling and thermal contraction of Cretaceous arc crust during a temporal gap in magmatic activity along the western Cordilleran margin. Nonmarine sediments of the Mesa Formation were deposited in small, steep-walled paleovalleys and basins that gradually filled and evolved to form through-going, low-energy ephemeral stream systems. The gradational upward transition from the Mesa to Comondú Formation records the early to middle Miocene onset of subduction-related arc magmatism in eastern Baja California and related westward progradation of alluvial volcaniclastic aprons shed from high-standing eruptive volcanic centers. Pre-existing streams were choked with the new influx of volcanic detritus, causing the onset of rapid sediment deposition by stream flows and dilute

Equipment performance and radiation protection status in X-ray fluoroscopy units in Sudan

International Nuclear Information System (INIS)

Ahmed, N. A.; Nayl, A. I.; Suliman, I. I.

2012-01-01

The number of fluoroscopy and fluoroscopically guided procedures has been substantially growing in developing countries at the same time advanced and sophisticated equipment are used in some hospitals. However, radiation protection requirements are not necessarily well adopted. In this study nine fluoroscopy X-ray units in Sudan were examined for compliance with international standards. The tests included: beam quality, entrance surface air kerma, image quality and radiation field measurements. Staff radiation protection tools such as lead aprons and eye glasses were also visually examined to find out whether international recommendations were fulfilled and to determine the level of staff awareness. The measured peak tube voltage deviation exceeded the recommended tolerance level in 30 % of the measurements. The results of patient doses measurements exceeded the recommended reference dose levels in 43 % of the measurements; however image quality and radiation field generally fulfilled the requirements for most units. The study revealed that a considerable number of fluoroscopy units were not performing according to the international standards and highlights the need of optimisation of radiation protection. (authors)

Status of researches in the field of safety of pressurized water reactors

International Nuclear Information System (INIS)

Couturier, Jean; Schwarz, Michel

2017-01-01

This collective publication proposes a synthesis of the status of researches performed in the field of safety of pressurized water reactors. They may discuss past, current and projected research works, involved actors, or lessons learned from these works. The authors propose a presentation of some research tools privileged by the IRSN for these researches: the CABRI and PHEBUS reactors, the GALAXIE experimental platform, and some other installations. Then they address researches related to loss-of-coolant accidents (two-phase thermohydraulics, fuel rod behaviour), to reactivity accidents, to accidents related to dewatering of irradiated fuel storage pools, to fires, to extreme aggressions of natural origin (earthquake, extreme flooding), to core fusion accidents (core heating and fusion within the vessel, vessel failure and apron erosion by corium, containment enclosure dynamic loading, release of radioactive products), to the behaviour of nuclear plant important metallic or civil works components and notably to their ageing, to organisational and human factors or more generally to social and human sciences (design of control rooms, safety organisation and management in EDF nuclear plants), and to other issues and research perspectives

Device for retaining oil gushing out in an uncontrolled fashion from offshore platforms. [German patent

Energy Technology Data Exchange (ETDEWEB)

Hambrock, H J

1978-11-23

The spread of oil which emerges on a water surface in case of a fault is to be prevented and its removal is to be made possible by a sort of floating fence. This type of oil barrier is formed by a blown up, floating hose on the water surface which may be filled with plastic foam. It surrounds the centrally placed possible place of emergence of the oil in a circle, this may be an offshore platform or a stationary tanker. The concentric position is ensured by radially tensioned ropes. The protective ring can normally be pulled in (above all during bad weather) and need only be expanded for a short time in case of a fault. In order to prevent oil collected inside the protective ring being washed under or over it by the wind or waves, a circular attachment in the form of a collar can be blown up in the upward direction, and a similar apron hanging downwards loaded with weights may be provided.

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

International Nuclear Information System (INIS)

Boumechra, Nadir; Hamdaoui, Karim

2008-01-01

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

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.

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

International Nuclear Information System (INIS)

Bashir, M. K. A.

2009-11-01

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)

Radiation protective clothing

International Nuclear Information System (INIS)

Ijiri, Yasuo; Fujinuma, Tadashi; Aso, Tsutomu.

1991-01-01

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.)

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.

Protective equipment of radiological protection and the worker wear

International Nuclear Information System (INIS)

Cassia, Flor Rita de; Huhn, Andrea; Lima, Gelbcke Francine

2013-01-01

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

Analysis of dose distribution in interventionist radiology professionals

International Nuclear Information System (INIS)

Mauricio, Claudia L.P.; Silva, Leonardo Peres; Canevaro, Lucia V.; Luz, Eara de Souza

2005-01-01

In this work, an evaluation was made of the distribution of dose received by professionals involved in some procedures of Interventional Radiology at hospitals and clinics in Rio de Janeiro, RJ, Brazil. For these measurements thermoluminescent dosemeters (TLD) of LiF: Mg, Ti (TLD100) were used, positioned at different points of the body of professionals: the hands, knees, neck, forehead and chest, inside and outside the lead apron. The measurements were made by procedure and/or a day of work, and the TLD were calibrated in equivalent operating magnitude of personal dose (Hp (d)) at different depths: 0.07 mm, 3 mm and 10 mm. In some procedures, physicians (holders of service and residents) received significant doses. The results show the importance of the appropriate training of these professionals and the use of personal protective equipment (PPE), such as thyroid shield, which is not always used. Based on these evaluations, some suggestions were made in order to optimize the dose values in these procedures and a discussion on the need for additional monitoring points

Designing shields for KeV photons with genetic algorithms

International Nuclear Information System (INIS)

Asbury, Stephen; Holloway, James P.

2011-01-01

Shielding of x-ray sources and low energy gamma rays is often accomplished with lead aprons, comprising a thin layer (0.5 mm to 1 mm) of lead or similar high-Z material. In previous work the authors used Genetic Algorithms to explore the design of a shadow shield for space applications. Now those techniques have been applied to the problem of shielding humans from low energy gamma radiation. This paper uses a simple geometry to explore layering various materials as a method to reduce mass and dose for thin gamma shields. The genetic algorithms discover layers of materials with various Z is in fact more effective than an equivalent mass of Pb alone for lower energy gammas, but as the incident radiation energy increases the efficacy of such layering diminishes. The utility of varying Z for lower energy gammas is in part due to their complementary K-edges, where one material compensates for the transmission that would occur just below the K-edge in another material. (author)

Time to Loosen the Apron Strings: Cohort-based Evaluation of a Learner-driven Remediation Model at One Medical School.

Science.gov (United States)

Bierer, S Beth; Dannefer, Elaine F; Tetzlaff, John E

2015-09-01

Remediation in the era of competency-based assessment demands a model that empowers students to improve performance. To examine a remediation model where students, rather than faculty, develop remedial plans to improve performance. Private medical school, 177 medical students. A promotion committee uses student-generated portfolios and faculty referrals to identify struggling students, and has them develop formal remediation plans with personal reflections, improvement strategies, and performance evidence. Students submit reports to document progress until formally released from remediation by the promotion committee. Participants included 177 students from six classes (2009-2014). Twenty-six were placed in remediation, with more referrals occurring during Years 1 or 2 (n = 20, 76 %). Unprofessional behavior represented the most common reason for referral in Years 3-5. Remedial students did not differ from classmates (n = 151) on baseline characteristics (Age, Gender, US citizenship, MCAT) or willingness to recommend their medical school to future students (p < 0.05). Two remedial students did not graduate and three did not pass USLME licensure exams on first attempt. Most remedial students (92 %) generated appropriate plans to address performance deficits. Students can successfully design remedial interventions. This learner-driven remediation model promotes greater autonomy and reinforces self-regulated learning.

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,

No More "Magic Aprons": Longitudinal Assessment and Continuous Improvement of Customer Service at the University of North Dakota Libraries

Science.gov (United States)

Clark, Karlene T.; Walker, Stephanie R.

2017-01-01

The University of North Dakota (UND) Libraries have developed a multi-award winning Customer Service Program (CSP) involving longitudinal assessment and continuous improvement. The CSP consists of iterative training modules; constant reinforcement of Customer Service Principles with multiple communication strategies and tools, and incentives that…

Systematic variations in sinter mineralogy, microtexture and diagenesis in modern siliceous hot springs: Clues for interpreting depositional conditions in ancient deposits

Science.gov (United States)

Mills, V. W.; Farmer, J. D.; Ruff, S. W.; Nunez, J.; Jahnke, L. L.

2011-12-01

glycolization methods, with XRPD. Results indicate that all of the acidic sinters we studied showed more extensive early diagenetic ordering of silica phases (opal-A to cristobalite and quartz) than the comparable microfacies of alkaline-neutral sinters. Clay analyses showed no evidence for smectitic (expansive) clays, but kaolin family clays (dickite, kaolinite and halloysite) were present in both acidic and alkaline sinters. The microfacies distribution observed for clays suggests: 1) dickite being more abundant in higher temperature (near-vent) microfacies, 2) kaolinite dominating mid-temperature outflow channels, slope and upper distal apron microfacies, and 3) halloysite being restricted to lower distal apron-marsh microfacies transitions. Future work will expand clay analyses to apply near-IR spectroscopy to a broader range of samples to assess the consistency with patterns suggested from XRPD.

An Analysis of Delay and Travel Times at Sao Paulo International Airport (AISP/GRU): Planning Based on Simulation Model

Science.gov (United States)

Santana, Erico Soriano Martins; Mueller, Carlos

2003-01-01

The occurrence of flight delays in Brazil, mostly verified at the ground (airfield), is responsible for serious disruptions at the airport level but also for the unchaining of problems in all the airport system, affecting also the airspace. The present study develops an analysis of delay and travel times at Sao Paulo International Airport/ Guarulhos (AISP/GRU) airfield based on simulation model. Different airport physical and operational scenarios had been analyzed by means of simulation. SIMMOD Plus 4.0, the computational tool developed to represent aircraft operation in the airspace and airside of airports, was used to perform these analysis. The study was mainly focused on aircraft operations on ground, at the airport runway, taxi-lanes and aprons. The visualization of the operations with increasing demand facilitated the analyses. The results generated in this work certify the viability of the methodology, they also indicated the solutions capable to solve the delay problem by travel time analysis, thus diminishing the costs for users mainly airport authority. It also indicated alternatives for airport operations, assisting the decision-making process and in the appropriate timing of the proposed changes in the existing infrastructure.

Radiation protection principles observance in Iranian dental schools

International Nuclear Information System (INIS)

Eskandarlou, A.; Ghazi-khanlou Sani, K.; Mehdizadeh, A. R.

2010-01-01

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.

Radiation exposure during equine radiography

International Nuclear Information System (INIS)

Ackerman, N.; Spencer, C.P.; Hager, D.A.; Poulos, P.W. Jr.

1988-01-01

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

Robotics in percutaneous cardiovascular interventions.

Science.gov (United States)

Pourdjabbar, Ali; Ang, Lawrence; Behnamfar, Omid; Patel, Mitul P; Reeves, Ryan R; Campbell, Paul T; Madder, Ryan D; Mahmud, Ehtisham

2017-11-01

The fundamental technique of performing percutaneous cardiovascular (CV) interventions has remained unchanged and requires operators to wear heavy lead aprons to minimize exposure to ionizing radiation. Robotic technology is now being utilized in interventional cardiology partially as a direct result of the increasing appreciation of the long-term occupational hazards of the field. This review was undertaken to report the clinical outcomes of percutaneous robotic coronary and peripheral vascular interventions. Areas covered: A systematic literature review of percutaneous robotic CV interventions was undertaken. The safety and feasibility of percutaneous robotically-assisted CV interventions has been validated in simple to complex coronary disease, and iliofemoral disease. Studies have shown that robotically-assisted PCI significantly reduces operator exposure to harmful ionizing radiation without compromising procedural success or clinical efficacy. In addition to the operator benefits, robotically-assisted intervention has the potential for patient advantages by allowing more accurate lesion length measurement, precise stent placement and lower patient radiation exposure. However, further investigation is required to fully elucidate these potential benefits. Expert commentary: Incremental improvement in robotic technology and telecommunications would enable treatment of an even broader patient population, and potentially provide remote robotic PCI.

Washing and changing uniforms: is guidance being adhered to?

Science.gov (United States)

Potter, Yvonne Camilla; Justham, David

To allay public apprehension regarding the risk of nurses' uniforms transmitting healthcare-associated infections (HCAI), national and local guidelines have been issued to control use, laundry and storage. This paper aims to measure the knowledge of registered nurses (RNs) and healthcare assistants (HCAs) working within a rural NHS foundation Trust and their adherence to the local infection prevention and control (IPC) standard regarding uniforms through a Trust-wide audit. Stratified random sampling selected 597 nursing staff and 399 responded (67%) by completing a short questionnaire based on the local standard. Responses were coded and transferred to SPSS (v. 17) for analysis. The audit found that nursing staff generally adhere to the guidelines, changing their uniforms daily and immediately upon accidental soiling, and wearing plastic aprons where indicated. At home, staff normally machine-wash and then iron their uniforms at the hottest setting. Nevertheless, few observe the local direction to place their newly-laundered uniforms in protective covers. This paper recommends a re-audit to compare compliance rates with baseline figures and further research into the reasons why compliance is lacking to sanction interventions for improvement, such as providing relevant staff education and re-introducing appropriate changing facilities.

A survey of the dentist attire and gender preferences in dentally anxious children

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Alexander Asokan

2016-01-01

Full Text Available Background: Anxiety about doctors among children is very common. White coat phobia which is a classical conditioning phenomenon is said to be prevalent among children. Objectives: To analyze the association between anxious states of children about dentists and their preference of dentist attire and gender in the dental office. Materials and Methods: The 9-12-year-old middle school children were selected for the study. Children were asked to fill a questionnaire containing children′s fear survey schedule-dental subscale (CFSS-DS and asked to prefer dental attire from four different pictures displaying the single anonymous dentist in four different attires in the same operator. The CFSS-DS gave the anxiety scale, and age, gender, and experience were also plotted against children preference in an apron, protective wear, and gender preference. Results were tabulated and statistically analyzed using Chi-square test. Results: About 718 (62% were scored as anxious children. Of all anxious children, 502 (69.9% had preference of colored attires of the dentist, and 408 (66.8% anxious children preferred dentist with protective wear. Female dentists were preferred by 452 (66% anxious children. Same gender preference was also prevalent.

How conservative is routine personal dosimetry monitoring in diagnostic radiology?

International Nuclear Information System (INIS)

Boetticher, H. von; Lachmund, J.; Hoffmann, W.

2007-01-01

Purpose: Dose values obtained by official personal radiation exposure monitoring are often considered equivalent to the effective dose of a person. This paper provides estimates of the extent of deviation between the two dose concepts under various conditions. Materials and Methods: Doses for patients and personnel were measured using thermoluminescence dosimeters for five different geometries at three work settings in a radiology department. Patients and personnel were simulated with anthropomorphic phantoms. Different types of protective clothing as well as permanent protection shields were considered in the calculations. Results: Dose values obtained by official personal dose monitoring are conservative only for specific radiation protection situations. With state-of-the-art personal protective equipment (wrap-around style lead apron with thyroid shield), the ratio between effective dose and personal dose varies between 0.6 and 1.25. Without thyroid protection the official personal dose systematically underestimates the effective dose: for protective clothing with 0.5 mm lead equivalent without thyroid shielding, the effective dose exceeds the personal dose by factors between 1.7 and 3.1. If protective clothing with lead equivalent 0.35 mm is used, this factor varies between 1.1 and 1.82. (orig.)

Preliminary Correlation Map of Geomorphic Surfaces in North-Central Frenchman Flat, Nevada Test Site

International Nuclear Information System (INIS)

Bechtel Nevada

2005-01-01

This correlation map (scale = 1:12,000) presents the results of a mapping initiative that was part of the comprehensive site characterization required to operate the Area 5 Radioactive Waste Management Site, a low-level radioactive waste disposal facility located in northern Frenchman Flat at the Nevada Test Site. Eight primary map units are recognized for Quaternary surfaces: remnants of six alluvial fan or terrace surfaces, one unit that includes colluvial aprons associated with hill slopes, and one unit for anthropogenically disturbed surfaces. This surficial geology map provides fundamental data on natural processes for reconstruction of the Quaternary history of northern Frenchman Flat, which in turn will aid in the understanding of the natural processes that act to develop the landscape, and the time-frames involved in landscape development. The mapping was conducted using color and color-infrared aerial photographs and field verification of map unit composition and boundaries. Criteria for defining the map unit composition of geomorphic surface units are based on relative geomorphic position, landform morphology, and degree of preservation of surface morphology. The bedrock units identified on this map were derived from previous published mapping efforts and are included for completeness

Accidental over-exposure from dental X-ray equipment

Energy Technology Data Exchange (ETDEWEB)

Phillips, B G [National Radiological Protection Board, Harwell (UK)

1976-07-01

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.

SedFoam-2.0: a 3-D two-phase flow numerical model for sediment transport

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J. Chauchat

2017-11-01

Full Text Available In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for sediment transport applications. The solver is extended from twoPhaseEulerFoam available in the 2.1.0 release of the open-source CFD (computational fluid dynamics toolbox OpenFOAM. In this approach the sediment phase is modeled as a continuum, and constitutive laws have to be prescribed for the sediment stresses. In the proposed solver, two different intergranular stress models are implemented: the kinetic theory of granular flows and the dense granular flow rheology μ(I. For the fluid stress, laminar or turbulent flow regimes can be simulated and three different turbulence models are available for sediment transport: a simple mixing length model (one-dimensional configuration only, a k − ε, and a k − ω model. The numerical implementation is demonstrated on four test cases: sedimentation of suspended particles, laminar bed load, sheet flow, and scour at an apron. These test cases illustrate the capabilities of SedFoam-2.0 to deal with complex turbulent sediment transport problems with different combinations of intergranular stress and turbulence models.

SedFoam-2.0: a 3-D two-phase flow numerical model for sediment transport

Science.gov (United States)

Chauchat, Julien; Cheng, Zhen; Nagel, Tim; Bonamy, Cyrille; Hsu, Tian-Jian

2017-11-01

In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for sediment transport applications. The solver is extended from twoPhaseEulerFoam available in the 2.1.0 release of the open-source CFD (computational fluid dynamics) toolbox OpenFOAM. In this approach the sediment phase is modeled as a continuum, and constitutive laws have to be prescribed for the sediment stresses. In the proposed solver, two different intergranular stress models are implemented: the kinetic theory of granular flows and the dense granular flow rheology μ(I). For the fluid stress, laminar or turbulent flow regimes can be simulated and three different turbulence models are available for sediment transport: a simple mixing length model (one-dimensional configuration only), a k - ɛ, and a k - ω model. The numerical implementation is demonstrated on four test cases: sedimentation of suspended particles, laminar bed load, sheet flow, and scour at an apron. These test cases illustrate the capabilities of SedFoam-2.0 to deal with complex turbulent sediment transport problems with different combinations of intergranular stress and turbulence models.

An evaluation and geochemical survey of the Farah Garan East Prospect, Southeast Asir, Kingdom of Saudi Arabia

Science.gov (United States)

Bookstrom, Arthur A.; El Komi, Mohamed; Christian, Ralph P.; Bazzari, Maher A.

1990-01-01

The Farah Garan East prospect (MODS 4886) is located in the southeastern part of the Precambrian Arabian Shield of Saudi Arabia, about 15 km east-northeast of Zahran Al Janub and 1 km northeast of the ancient mines at Farah Garan. Ore minerals at the Farah Garan East prospect are pyrite, tennantite, galena, and sphalerite. These are sparsely and erratically distributed in west-dipping beds of dolomite, dolomite-talc breccia, and carbonate-sericite phyllite, and in associated breccias and zones of carbonate-altered mafic metavolcanic rocks, all of Precambrian age. Concordant beds of dolomite and carbonate-sericite phyllite are interlayered with metavolcanic rocks and are interpreted as volcanic-related submarine hydrothermal deposits of Precambrian age. Funnel-shaped bodies of dolomite-talc breccia that crop out near the north and south ends of the dolomite beds are interpreted as submarine hot-spring vent breccias. Aprons of exhalative dolomite thin laterally outward from these vents. Discordant and concordant zones of carbonate-altered metavolcanic rocks, east of and structurally below the hot-spring vents, probably represent pathways of hydrothermal circulation along networks of fractures in volcanic rocks, subjacent to these Precambrian submarine hot-spring vents.

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)

Almeida, Claudio Domingues de

2005-01-01

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

Ovarian Follicular Dynamics around Estrus in Beetal and Teddy Goats

Directory of Open Access Journals (Sweden)

Hasan Riaz, Nasim Ahmad* and Muhammad Rizwan Yousuf

2013-01-01

Full Text Available Due to higher fecundity rate over Beetal goats, it is assumed that Teddy goats have higher ovarian activity. Therefore, the current study tested the hypothesis that ovarian follicular population i.e. number of small (2-4 mm, medium (>4-6 mm and large follicles (>6 mm, size of the ovulatory follicle, and ovulation rate (No. of CL/No of ovulated goats, using transrectal ultrasonography are different between Beetal and Teddy goats of Pakistani origin. Beetal (n=6 and Teddy (n=8 does were synchronized using double PGF2a injections 10 d apart and were scanned on Days -2, 0 (estrus and +2. The onset of estrus was assessed by aproned bucks. Mean number of small follicles were higher (P<0.05 in Beetal goats, compared to Teddy goats, on days -2, estrus and +2. The ovulatory follicle diameter, and ovulation rate were found non-significant between Beetal and Teddy goats. It is concluded that Beetal goats have greater population of small follicles around estrus compared to Teddy goats. Future studies can be based on the follicle recruitment and atretic factors in Beetal goats to enhance the production.

Statistical analysis of ground-water contamination at the alert apron and northern landfill areas of Wurtsmith AFB, Michigan. Final report

Energy Technology Data Exchange (ETDEWEB)

Hunter, P.; Naber, S.; Verducci, J.

1988-07-01

Two plumes of contamination are analyzed to determine their extent, composition, and movement. The large number of ground-water monitoring wells sampled over the past eight years at Wurtsmith AFB allow this analysis to be performed directly from empirical data, with minimal assumptions about solute transport mechanisms. Conclusions are drawn about the likely sources of contamination in the two plumes, the adequacy of the data for making risk assessments, and the likely consequences of alternative programs of remediation.

Prenatal bisphenol a exposure and dysregulation of infant hypothalamic-pituitary-adrenal axis function: findings from the APrON cohort study.

Science.gov (United States)

Giesbrecht, Gerald F; Ejaredar, Maede; Liu, Jiaying; Thomas, Jenna; Letourneau, Nicole; Campbell, Tavis; Martin, Jonathan W; Dewey, Deborah

2017-05-19

Animal models show that prenatal bisphenol A (BPA) exposure leads to sexually dimorphic disruption of the neuroendocrine system in offspring, including the hypothalamic-pituitary-adrenal (HPA) neuroendocrine system, but human data are lacking. In humans, prenatal BPA exposure is associated with sex-specific behavioural problems in children, and HPA axis dysregulation may be a biological mechanism. The objective of the current study was to examine sex differences in associations between prenatal maternal urinary BPA concentration and HPA axis function in 3 month old infants. Mother-infant pairs (n = 132) were part of the Alberta Pregnancy Outcomes and Nutrition study, a longitudinal birth cohort recruited (2010-2012) during pregnancy. Maternal spot urine samples collected during the 2nd trimester were analyzed for total BPA and creatinine. Infant saliva samples collected prior to and after a blood draw were analyzed for cortisol. Linear growth curve models were used to characterize changes in infant cortisol as a function of prenatal BPA exposure. Higher maternal BPA was associated with increases in baseline cortisol among females (β = 0.13 log μg/dL; 95% CI: 0.01, 0.26), but decreases among males (β = -0.22 log μg/dL; 95% CI: -0.39, -0.05). In contrast, higher BPA was associated with increased reactivity in males (β = .30 log μg/dL; 95% CI: 0.04, 0.56) but decreased reactivity in females (β = -0.15 log μg/dL; 95% CI: -0.35, 0.05). Models adjusting for creatinine yielded similar results. Prenatal BPA exposure is associated with sex-specific changes in infant HPA axis function. The biological plausibility of these findings is supported by their consistency with evidence in rodent models. Furthermore, these data support the hypotheses that sexually dimorphic changes in children's behaviour following prenatal BPA exposure are mediated by sexually dimorphic changes in HPA axis function.

Revised stratigraphy and reinterpretation of the Miocene Pohang basinfill, SE Korea: sequence development in response to tectonism and eustasy in a back-arc basin margin

Science.gov (United States)

Sohn, Y. K.; Rhee, C. W.; Shon, H.

2001-09-01

The Miocene Pohang Basin is a pull-apart basin formed along the eastern continental margin of Korea (ECMK) during the back-arc opening of the East Sea (Sea of Japan). The basin is filled by more than 1 km thick, nonmarine to deep-marine strata. These strata show extreme vertical and lateral lithofacies changes and have caused decades-long controversies on their nature and stratigraphy. Previous sedimentological studies suggest that the basinfill was deposited by a series of contemporaneously developed depositional systems, including fan delta, prodelta, slope apron, and basin plain. Detailed mapping and magnetotelluric surveying show, however, that the basinfill is composed of several packages of strata (sequences) that are bounded by distinct and laterally persistent stratigraphic discontinuities (sequence boundaries). This suggests that the depositional systems in the Pohang Basin developed sequentially rather than contemporaneously. Six packages of strata are identified in the basin: a nonmarine to shallow marine (transgressive) sequence (Sequence 1), a Gilbert-type-delta conglomerate (Sequence 2), and alternations of submarine conglomerates and hemipelagic mudstones (Sequences 3-6). The conglomerates and hemipelagic mudstones of the latter four sequences are interpreted to represent lowstand depositional systems (slope apron, submarine fan, and high-gradient delta) and condensed intervals, respectively. Compilation of geochronologic, paleomagnetic, and biostratigraphic data suggests that Sequence 1 formed during the gradual subsidence of the ECMK prior to 17 Ma, whereas Sequence 2 formed in response to abrupt downfaulting of the Pohang Basin at about 17 Ma. Both sequences are interpreted to have developed in response to the early Miocene back-arc-opening tectonism of the East Sea. On the other hand, Sequences 3-6 formed between 17 and about 10.5 Ma. The Pohang Basin was subject to only minor tectonism during this period and could record global sea

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

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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

Evaluation of the efficiency of different methods of personal dosimetry in vascular interventional radiology

International Nuclear Information System (INIS)

Bacchim Neto, F.A.; Alves, A.F.F.; Rosa, M.E.D.; Pina, D.R.

2017-01-01

Interventional Radiology - IR is the area of medicine that provides the largest occupational exposures. The dose values to which interventionists are exposed are difficult to standardize. The objective of the study is to perform a complete evaluation of occupational exposures and to determine the efficiency of different personal dosimetry methods used in IR. We evaluated the efficiencies of 6 different personal dosimetry methodologies used internationally to estimate the effective dose received by interventional professionals. And, based on this analysis, determine the characteristics of each methodology. One of the methods of personal dosimetry recommended by Brazilian legislation was the most conservative, overestimating, on average, the effective dose of professionals by up to 200%, reaching maximum values close to 400%. The most accurate method was that used in North America. This method did not overestimate the effective dose of the professionals more than a few percent and their standard deviation relative to the effective reference dose were the lowest. Based on these results, the choice of methodologies employing at least two dosimeters, one under and above protective aprons is recommended. In addition, in some situations where the dose in the hands may be high, additional dosimeters for this region are also recommended

Novel posterior reconstruction technique during robot-assisted laparoscopic prostatectomy: description and comparative outcomes.

Science.gov (United States)

Jeong, Chang Wook; Oh, Jong Jin; Jeong, Seong Jin; Hong, Sung Kyu; Byun, Seok-Soo; Choe, Gheeyoung; Lee, Sang Eun

2012-07-01

The aim of the present study was to assess the impact of a novel posterior reconstruction technique during robot-assisted laparoscopic prostatectomy on continence recovery. A total of 116 consecutive patients who received the novel posterior reconstruction (case group) were retrospectively compared with a cohort of 126 patients who did not receive posterior reconstruction (control group). The primary end-point was the duration of continence recovery (no pad use) after robot-assisted laparoscopic prostatectomy. The posterior reconstruction was obtained by opposing the median dorsal fibrous raphe to the posterior counterpart of the detrusor apron, rather than the Denonvilliers' fascia. The case group showed higher continence rates at all points of evaluation, which were 2 weeks (30.1% vs 19.8%), 1 month (58.4% vs 45.7%), 3 months (82.7% vs 70.5%) and 6 months postoperatively (95.3% vs 86.4%) (P = 0.007). Application of the novel posterior reconstruction technique, age and length of membranous urethra were significant variables for the complete recovery of continence on multivariable analysis. This study shows that the application of this novel PR technique significantly improves the recovery of continence in patients undergoing robot-assisted laparoscopic prostatectomy. © 2012 The Japanese Urological Association.

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.

Radiation absorbed doses at radiographic examination of third molars

International Nuclear Information System (INIS)

Rehnmark-Larsson, S.; Stenstroem, B.; Julin, P.; Richter, S.; Huddinge University Hospital

1981-01-01

The radiation absorbed doses to critical organs, i.e. the thyroid and salivary glands and the gonadal region, were measured at radiographic examination of third molars. A tissue equivalent phantom was used together with ionization chamber detectors and TLDs. The greatest thyroid dose, 35 μGy, came from a mandibular disto-oblique projection with the circular tube collimator and Ultra-Speed film. The doses in different parts of the parotid gland from the disto-oblique mandibular projection with Ultra-Speed film ranged between 2.65 and 0.052 mGy. the corresponding doses in the submandibular gland were 1.74 mGy beneath the mandible and 0.458 mGy in the fovea. A rectangular tube collimator reduced the doses by approximately 50 %. The Ekta-Speed film requirted approximately 40 % lower exposure than the Ultra-Speed film. A horizontal radiation shield reduced the thyroid doses by between 12 and 46 % and the gonadal doses by between 50 and 95 %. The reduction effect from the shield was relatively greater when using the larger aperture of the tube collimator. Combinations of leaded aprons and soft leaded collars reduced the thyroid doses between 15 and 42 % and the gonadal doses by two orders of magnitude. (Authors)

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.

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

International Nuclear Information System (INIS)

Hollister, C.D.

1979-01-01

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% CaCO 3 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

Microbiological investigation of halal butchery products and butchers' premises.

Science.gov (United States)

Little, C; Gillespie, I; de Louvois, J; Mitchell, R

1999-06-01

Halal butchers' premises were investigated as they had not been represented in a recent study of butchery products and butchers' premises conducted by the Local Authorities Coordinating Body on Food and Trading Standards and the PHLS. This study examined 183 raw prepared meats and 212 environmental samples from 105 halal butcher premises. Only raw meats were prepared on 97 of the premises visited; and the types of meat prepared on the remaining eight premises was not specified. Four halal butchers sold cooked meats prepared elsewhere. Salmonella spp. and Campylobacter spp. were detected in 12 (7%) and 52 (28%) of the 183 raw meat products, respectively. Five raw prepared meats (3%) contained both salmonella and campylobacter. Vero cytotoxin producing Escherichia coli O157 was isolated from a raw meat product that also contained campylobacter. No cooked meat products were available for collection. The physical separation of raw and unwrapped cooked meat products in premises that prepared raw and sold cooked meats was not recorded. Apron cloths were the most heavily contaminated environmental samples examined; hygiene indicator microorganisms indicated an increased risk of cross contamination. Managers in 85 premises had received no food hygiene training and 88 premises had no hazard analysis system in place. Improvements are needed to reduce the risk of cross contamination.

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

International Nuclear Information System (INIS)

Ferriz D, H.

1977-01-01

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)

Analysis of occupational doses in interventional radiology and cardiology installations

International Nuclear Information System (INIS)

Vano, E.; Gonzalez, L.; Ten, J.I.; Guibelalde, E.; Fernandez, J.M.

1997-01-01

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.cm 2 . 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)

Research note: Molecular subtyping of Salmonella enterica serovar Tshiongwe recently isolated in Malaysia during 2001-2002.

Science.gov (United States)

Thong, Kwai Lin; Bakeri, Shamsilawani Ahmad; Lai, Kin Seng; Koh, Yin Tee; Taib, Mohd Zainuldin; Lim, V K E; Yasin, Rohani Md

2004-03-01

Pulsed field gel electrophoresis (PFGE) and antimicrobial susceptibility analysis were undertaken on twenty-three strains of Salmonella enterica serovar Tshiongwe, an unusual serovar, which recently emerged in Malaysia. Antimicrobial susceptibility analysis showed that all the strains were sensitive to ampicilin, chloramphenicol, cotrimoxazole, and kanamycin. Twenty (87%) and 8 (3.5%) strains had resistance to tetracycline and streptomycin respectively. PFGE analysis subtyped 23 strains into 10 profiles (Dice coefficient of similarity, F = 0.7-1.0). The predominant profile, X1 was found in both clinical and environmental isolates and was widely distributed in different parts of Malaysia during the study period. In addition, isolates recovered from food, a hand-towel, apron and the surface of a table-top in one particular location had unique, indistinguishable profiles (X4/4a) and identical antibiograms. Similarly, isolates from cooked meat and a chopping board had PFGE profiles similar to some human isolates. These probably indicated cross-contamination and poor hygiene in food practices, hence contributing to Salmonellosis. Factors causing the emergence of this rare Salmonella serovar being responsible for food poisoning episodes during the study period remained unclear. The study reiterated the usefulness and versatility of PFGE in the molecular subtyping of this rare Salmonella serovar in Malaysia.

ICRP Publication 139: Occupational Radiological Protection in Interventional Procedures.

Science.gov (United States)

López, P Ortiz; Dauer, L T; Loose, R; Martin, C J; Miller, D L; Vañó, E; Doruff, M; Padovani, R; Massera, G; Yoder, C

2018-03-01

In recent publications, such as Publications 117 and 120, the Commission provided practical advice for physicians and other healthcare personnel on measures to protect their patients and themselves during interventional procedures. These measures can only be effective if they are encompassed by a framework of radiological protection elements, and by the availability of professionals with responsibilities in radiological protection. This framework includes a radiological protection programme with a strategy for exposure monitoring, protective garments, education and training, and quality assurance of the programme implementation. Professionals with responsibilities in occupational radiological protection for interventional procedures include: medical physicists; radiological protection specialists; personnel working in dosimetry services; clinical applications support personnel from the suppliers and maintenance companies; staff engaged in training, standardisation of equipment, and procedures; staff responsible for occupational health; hospital administrators responsible for providing financial support; and professional bodies and regulators. This publication addresses these elements and these audiences, and provides advice on specific issues, such as assessment of effective dose from dosimeter readings when an apron is worn, estimation of exposure of the lens of the eye (with and without protective eyewear), extremity monitoring, selection and testing of protective garments, and auditing the interventional procedures when occupational doses are unusually high or low (the latter meaning that the dosimeter may not have been worn).

Evaluation of the efficiency of different methods of personal dosimetry in vascular interventional radiology; Avaliação da eficiência de diferentes métodos de dosimetria pessoal em radiologia intervencionista vascular

Energy Technology Data Exchange (ETDEWEB)

Bacchim Neto, F.A., E-mail: fernando.bacchim@lnls.br [Laboratório Nacional de Luz Síncrotron (LNLS), Campinas-SP (Brazil). Centro Nacional de Pesquisa em Energia e Materiais; Alves, A.F.F.; Rosa, M.E.D. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Instituto de Biociências; Pina, D.R. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Departamento de Doenças Tropicais e Diagnóstico por Imagem

2017-07-01

Interventional Radiology - IR is the area of medicine that provides the largest occupational exposures. The dose values to which interventionists are exposed are difficult to standardize. The objective of the study is to perform a complete evaluation of occupational exposures and to determine the efficiency of different personal dosimetry methods used in IR. We evaluated the efficiencies of 6 different personal dosimetry methodologies used internationally to estimate the effective dose received by interventional professionals. And, based on this analysis, determine the characteristics of each methodology. One of the methods of personal dosimetry recommended by Brazilian legislation was the most conservative, overestimating, on average, the effective dose of professionals by up to 200%, reaching maximum values close to 400%. The most accurate method was that used in North America. This method did not overestimate the effective dose of the professionals more than a few percent and their standard deviation relative to the effective reference dose were the lowest. Based on these results, the choice of methodologies employing at least two dosimeters, one under and above protective aprons is recommended. In addition, in some situations where the dose in the hands may be high, additional dosimeters for this region are also recommended.

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

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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.

[Optimizing staff radiation protection in radiology by minimizing the effective dose].

Science.gov (United States)

von Boetticher, H; Lachmund, J; Hoffmann, W; Luska, G

2006-03-01

In the present study the optimization of radiation protection devices is achieved by minimizing the effective dose of the staff members since the stochastic radiation effects correlate to the effective dose. Radiation exposure dosimetry was performed with TLD measurements using one 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. It was shown that the doses of the unshielded organs (thyroid, parts of the active bone marrow) contribute significantly to the effective dose of the staff. Therefore, there is no linear relationship between the shielding factors for protective garments and the effective dose. An additional thyroid protection collar reduces the effective dose by a factor of 1.7 - 3.0. X-ray protective clothing with a 0.35 mm lead equivalent and an additional thyroid protection collar provides better protection against radiation than an apron with a 0.5 mm lead equivalent but no collar. The use of thyroid protection collars is an effective preventive measure against exceeding occupational organ dose limits, and a thyroid shield also considerably reduces the effective dose. Therefore, thyroid protection collars should be a required component of anti-X protection.

Knowledge, Attitudes and Performance of Dental Practitioners in Isfahan-Iran about Biologic Effects of Ionizing Radiation and Protection Against them in 2011

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Hamid Badrian

2013-01-01

Full Text Available Introduction: Increasing use of dental radiography makes necessitates of increasing awareness and appropriate performance about ionizing radiation protection. The present study was done with the aim of evaluation of awareness, attitude and performance levels of dental practitioners in the city of Isfahan about ionizing radiation and protection against them.Materials & Methods: In this descriptive-analytic study a questionnaire including questions for evaluating of awareness, attitude and performance levels and demographic information was distributed among 184 dentists in the city of Isfahan. The data were analyzed by means of student t test and Pearson correlation coefficient in SPSS software (α=0.05. Results: In the present study 73.2% of dentists had weak awareness level 25.6% and 1.2% of dentists had moderate and good awareness levels respectively. Twentyfour and 76 percent had good and apathetic attitudes. Ten and 4.5 percent of dentists have been using lead apron and thyroidal necklace for their patients respectively. Experience and awareness had significant inverse correlation with eachother (P=0.004, r =-0.218.Conclusion: According to the results of the presents study, the awareness of dentists was weak and academic education as well as post-graduate education is necessary.

Decommissioning of a hot cell with high levels of contamination. Experience during the Undressed of Workers

International Nuclear Information System (INIS)

Martinez, A.; Sancho, C.

1998-01-01

The object of this work is to show the radiological controls in decommissioning of the inner of the Base Cell of the Nuclear Facility of CIEMAT, IN-04 (Metallurgy Hot Cells) and the experience during the undressed of workers in decommissioning of this cell. The workers were equipped with one cotton overalls and one or two paper overalls of one-use. Also, when the radiation levels are high, the workers were equipped with leaded glasses and aprons. The protection equipment for internal contamination were autonomous and semi-autonomous respiratory equipment. Due to a high superficial contamination levels, two areas were established in order to proceed to the undressed of the workers when these concluded their work. The first area was a confined enclosure by joined to the hot cell, where an expert of the Radiation Protection Service (RPS), trained for it, take off the first paper overall and the first pair of gloves to the worker that come out the hot cells. The second area was at the exist of the Load Zone, where another expert of PRS, take off the second paper overall, the second pair of gloves and dislocated the pipe of air of the semi-autonomous respiratory equipment, to the worker that come out this zone. (Author)

Occupational Radiation Dose for Medical Workers at a University Hospital

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M.H. Nassef

2017-11-01

Full Text Available Occupational radiation doses for medical workers from the departments of diagnostic radiology, nuclear medicine, and radiotherapy at the university hospital of King Abdul-Aziz University (KAU were measured and analysed. A total of 100 medical radiation workers were monitored to determine the status of their average annual effective dose. The analysis and the calibration procedures of this study were carried out at the Center for Radiation Protection and Training-KAU. The monitored workers were classified into subgroups, namely, medical staff/supervisors, technicians, and nurses, according to their responsibilities and specialties. The doses were measured using thermo luminescence dosimeters (TLD-100 (LiF:Mg,Ti placed over the lead apron at the chest level in all types of workers except for those in the cath lab, for whom the TLD was placed at the thyroid protective collar. For nuclear medicine, a hand dosimeter was used to measure the hand dose distribution. The annual average effective doses for diagnostic radiology, nuclear medicine, and radiotherapy workers were found to be 0.66, 1.56, and 0.28 mSv, respectively. The results of the measured annual dose were well below the international recommended dose limit of 20 mSv. Keywords: Occupational radiation dose, radiation workers, TLD, radiation protection

Preliminary results of chronostratigraphic field work, OSL-dating and morphogenetic reconstruction of an alluvial apron at Alborz southern foothill, Damghan basin, Iran

Science.gov (United States)

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

2014-05-01

Here we present preliminary results of a chronostratigraphic study of an alluvial fan in the Damghan Basin, northern Iran. The basin sediments date back to the Mio- and Pliocene and therefore represent the starting point of alluvial fan aggradation. Today, the still active alluvial fans prograde from the Albors Mountain ranges and sit on the older sediment bodies. In this study, our focus is on the late Pleistocene to Holocene alluvial fan sedimentation history. The upper stratigraphy of the alluvial fans and intercalated lake deposits is characterized by six individual layers of gravels and fines, representing six different stratigraphic units. These units are described and classified by detailed geomorphological and stratigraphic mapping. To establish an alluvial fan chronology, six profiles were sampled for OSL dating. As expected, due to the high-energy transport system of alluvial fan aggradation in semi-desert environments, OSL dating of these sediments is challenging due to the problem of insufficient bleaching. Consequently, most of the samples are interpreted as maximum ages. However, the measurements show a consistent internal age structure and the overall OSL-based chronology is in agreement with the age model derived from our geomorphological analysis. As a first interpretation, based on surveyed geomorphological features and chronological analysis, we could identify seven morphodynamic phases, leading to a genetic model of alluvial fan aggradation. The oldest Pleistocene age estimate is derived from a former lake terrace. The following ages represent ongoing lake sediment deposition and the development of a proximal and mid-fan gravel cover. After the youngest lake deposits were accumulated within the Holocene, the lake starts to retreat and small alluvial fans are filling up the former lake bottom. This last sedimentation phase can be divided in at least two sub-phases, probably coupled to a lateral shifting of the active depositional lobe and to the abandonment and shallow incision of mid fan surfaces.

Comparison of Shallow Survey 2012 Multibeam Datasets

Science.gov (United States)

Ramirez, T. M.

2012-12-01

The purpose of the Shallow Survey common dataset is a comparison of the different technologies utilized for data acquisition in the shallow survey marine environment. The common dataset consists of a series of surveys conducted over a common area of seabed using a variety of systems. It provides equipment manufacturers the opportunity to showcase their latest systems while giving hydrographic researchers and scientists a chance to test their latest algorithms on the dataset so that rigorous comparisons can be made. Five companies collected data for the Common Dataset in the Wellington Harbor area in New Zealand between May 2010 and May 2011; including Kongsberg, Reson, R2Sonic, GeoAcoustics, and Applied Acoustics. The Wellington harbor and surrounding coastal area was selected since it has a number of well-defined features, including the HMNZS South Seas and HMNZS Wellington wrecks, an armored seawall constructed of Tetrapods and Akmons, aquifers, wharves and marinas. The seabed inside the harbor basin is largely fine-grained sediment, with gravel and reefs around the coast. The area outside the harbor on the southern coast is an active environment, with moving sand and exposed reefs. A marine reserve is also in this area. For consistency between datasets, the coastal research vessel R/V Ikatere and crew were used for all surveys conducted for the common dataset. Using Triton's Perspective processing software multibeam datasets collected for the Shallow Survey were processed for detail analysis. Datasets from each sonar manufacturer were processed using the CUBE algorithm developed by the Center for Coastal and Ocean Mapping/Joint Hydrographic Center (CCOM/JHC). Each dataset was gridded at 0.5 and 1.0 meter resolutions for cross comparison and compliance with International Hydrographic Organization (IHO) requirements. Detailed comparisons were made of equipment specifications (transmit frequency, number of beams, beam width), data density, total uncertainty, and

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

Orthopedic surgeons’ knowledge regarding risk of radiation exposition: a survey analysis

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Tunçer Nejat

2017-01-01

Full Text Available Introduction: The purpose of this study is to evaluate the knowledge levels of orthopedic surgeons working in Turkey about the uses and possible risks of fluoroscopy and assess methods for preventing radiation damage. Methods: A questionnaire with a total of 12 questions was sent to 1121 orthopedic surgeons working in Turkey. The questionnaire evaluated participants’ knowledge about the uses and risks of fluoroscopy and methods for preventing damage. One thousand and twenty-four orthopedic surgeons were found to be suitable for inclusion in the study. The effects of fluoroscopy on patients were not assessed in our study. Results: The data obtained were statistically evaluated. Of the surveyed surgeons, 313 (30% had used fluoroscopy in over 50% of their operations. The average number of fluoroscopy shots per case was 54.5. A lead apron was the most commonly used (88% protection from the harmful effects of radiation. Fluoroscopy shots were performed with the help of operating room personnel (86%. A dosimeter was used 5% of the time. Conclusion: According to the survey results, the need for fluoroscopy was very high in orthopedic surgery. However, orthopedic surgeons have inadequate knowledge about the uses and risks of fluoroscopy and methods for preventing damage. Therefore, we believe that training on this topic should be provided to all orthopedic surgeons.

Orthopedic surgeons' knowledge regarding risk of radiation exposition: a survey analysis.

Science.gov (United States)

Tunçer, Nejat; Kuyucu, Ersin; Sayar, Şafak; Polat, Gökhan; Erdil, İrem; Tuncay, İbrahim

2017-01-01

The purpose of this study is to evaluate the knowledge levels of orthopedic surgeons working in Turkey about the uses and possible risks of fluoroscopy and assess methods for preventing radiation damage. A questionnaire with a total of 12 questions was sent to 1121 orthopedic surgeons working in Turkey. The questionnaire evaluated participants' knowledge about the uses and risks of fluoroscopy and methods for preventing damage. One thousand and twenty-four orthopedic surgeons were found to be suitable for inclusion in the study. The effects of fluoroscopy on patients were not assessed in our study. The data obtained were statistically evaluated. Of the surveyed surgeons, 313 (30%) had used fluoroscopy in over 50% of their operations. The average number of fluoroscopy shots per case was 54.5. A lead apron was the most commonly used (88%) protection from the harmful effects of radiation. Fluoroscopy shots were performed with the help of operating room personnel (86%). A dosimeter was used 5% of the time. According to the survey results, the need for fluoroscopy was very high in orthopedic surgery. However, orthopedic surgeons have inadequate knowledge about the uses and risks of fluoroscopy and methods for preventing damage. Therefore, we believe that training on this topic should be provided to all orthopedic surgeons. © The Authors, published by EDP Sciences, 2017.

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.

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

International Nuclear Information System (INIS)

Al-Haj, A.N.; Lobriguito, A.M.; Lagarde, C.S.

2003-01-01

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 kV p 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)

The relation of cognitive load and pupillary unrest.

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Müller, Andreas; Petru, Raluca; Seitz, Lucia; Englmann, Ines; Angerer, Peter

2011-06-01

This study examines the relationship between pupillary unrest (PU) and cognitive load. PU represents a measure of reduced central nervous tonic arousal (sleepiness). A loss of tonic arousal can be associated with difficulties in maintaining the required level of performance. Thus, the measurement of tonic arousal in occupational contexts can help to prevent overload or errors. We compared a group with high cognitive load (30 apron controllers of an international airport) with a control group with low cognitive load (63 healthy people during their free time) in a non-randomized experimental design with pre- and post-test assessment of PU. PU was scanned by an infrared sensor with a frequency of 25 Hz and a resolution of .05 mm. To control for circadian effects, measurements for both groups were taken at the same time of the day. High PU at the start of the shift correlated with high perceived load during the shift. There were no indications of reverse effects. Analyses of group x time effects with generalized linear models (repeated measures) revealed that cognitive load did in no way affected PU. Initially low tonic arousal (indicated by high PU) may predict subsequent workload, but being exposed to high cognitive load does not influence tonic arousal after the end of the shift. With that, the study contributes to valid interpretations of pupillary unrest measurements in occupational contexts.

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

International Nuclear Information System (INIS)

Mohammed, Sirelkatim Khogali

2013-04-01

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)

Nesting biology of Paravespa rex (von Schulthess 1924) (Hymenoptera: Vespidae: Eumeninae) in the Crimea, Ukraine.

Science.gov (United States)

Fateryga, Alexander V; Ivanov, Sergey P

2013-01-01

Paravespa rex is the only species of the wasp genus Paravespa that occurs in Europe. Females of this species nest in clay loam soil of proluvial terraces and deluvial aprons of badlands. The nests are vertical burrows 10-12 cm deep, surmounted by turrets of two distinct architectural forms: funnel-shaped and curved. The nests contain 1-3 vertical cells (mean-1.9) not different from the other parts of nest burrow. An egg is laid onto the bottom of the cell without attaching; it stands vertically via the moist adhesive surface of the bottom and then with the help of the position of the first prey, which is laid around the egg. The species is univoltine; prepupae hibernate in the cocoon for one or several years. Females hunt for caterpillars of two species of the noctuid genus Heliotis; 3-7 caterpillars (mean-3.7) are stored per cell. Adult feeding is recorded on flowers of Thymus tauricus. Males look for females at their water-collecting sites. Only a third of the cells are successful; the other ones are damaged by rain and the gold wasp, Chrysis valesiana, parasitizing in the nests. Nest-building and hunting activity of the species is described with the duration of certain nesting acts. Nesting biology of Paravespa species, rarity of P. rex, turret function, egg position, and measures for species conservation are discussed.

Vegetation growth patterns on six rock-covered UMTRA Project disposal cells

International Nuclear Information System (INIS)

1992-02-01

This study assessed vegetation growth patterns, the potential impacts of vegetation growth on disposal cell cover integrity, and possible measures that could be taken to monitor and/or control plant growth, where necessary, on six Uranium Mill Tailings Remedial Action (UMTRA) Project rock-covered disposal cells. A large-scale invasion of volunteer plants was observed on the Shiprock and Burrell disposal cells. Plant growth at the South Clive, Green River, and Tuba City disposal cells was sparse except for the south rock apron and south slope of the Tuba City disposal cell, where windblown sand had filled up part of the rock cover and plant growth was observed. The rock-covered topslope of the Collins Ranch disposal cell was intentionally covered with topsoil and vegetated. Plant roots growing on the disposal cells are changing the characteristics of the cover by drying out the radon barrier, encouraging the establishment of soil-building processes in the bedding and radon barrier layers, creating channels in the radon barrier, and facilitating ecological succession, which could lead to the establishment of additional deep-rooted plants on the disposal cells. If left unchecked, plant roots would reach the tailings at the Burrell and Collins Ranch disposal cells within a few years, likely resulting in the transport of contaminants out of the cells

Nonlocal Sediment Transport on Steep Lateral Moraines, Eastern Sierra Nevada, California, USA

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Doane, Tyler H.; Furbish, David Jon; Roering, Joshua J.; Schumer, Rina; Morgan, Daniel J.

2018-01-01

Recent work has highlighted the significance of long-distance particle motions in hillslope sediment transport. Such motions imply that the flux at a given hillslope position is appropriately described as a weighted function of surrounding conditions that influence motions reaching the given position. Although the idea of nonlocal sediment transport is well grounded in theory, limited field evidence has been provided. We test local and nonlocal formulations of the flux and compare their ability to reproduce land surface profiles of steep moraines in California. We show that nonlocal and nonlinear models better reproduce evolved land surface profiles, notably the amount of lowering and concavity near the moraine crest and the lengthening and straightening of the depositional apron. The analysis provides the first estimates of key parameters that set sediment entrainment rates and travel distances in nonlocal formulations and highlights the importance of correctly specifying the entrainment rate when modeling land surface evolution. Moraine evolution associated with nonlocal and nonlinear transport formulations, when described in terms of the evolution of the Fourier transform of the moraine surface, displays a distinct behavior involving growth of certain wave numbers, in contrast to the decay of all wave numbers associated with linear transport. Nonlinear and nonlocal formulations share key mathematical elements yielding a nonlinear relation between the flux and the land surface slope.

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

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Wu, J R; Huang, T Y; Wu, D K; Hsu, P C; Weng, P S

1991-07-15

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, we 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.

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

International Nuclear Information System (INIS)

Wu, J.R.; Huang, T.Y.; Wu, D.K.; Hsu, P.C.; Weng, P.S.

1991-01-01

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

Potential of radioactive and other waste disposals on the continental margin by natural dispersal processes

International Nuclear Information System (INIS)

Ryan, W.B.F.; Farre, J.A.

1983-01-01

Mass wasting, an erosional process, has recently been active at deepwater waste disposal sites on the mid-Atlantic margin of the United States. On the continental slope there is a subsea drainage network consisting of canyons, gullies, and chutes, and there are meandering channels, erosional scars, and debris aprons present on the continental rise. Fresh-looking blocks of 40 to 45 million-year-old marl and chalk (from cobble to boulder size) are strewn among canisters of low-level radioactive wastes. Some of the blocks have traveled from their original place of deposition for distances in excess of 170 km. Waste containers on the continental slope and rise cannot be considered to be disposed of permanently. The drainage network of the slope provides a natural process for collecting wastes over a catchment area, and for concentrating it with interim storage in canyons. Erosion by slumping, sliding, and debris flows ultimately will transport the wastes from the continental slope and disperse it over potentially large areas on the continental rise and abyssal plain. If it is desirable that the wastes be buried in the seafloor and isolated from the environment, then the continental slope and rise are not attractive repositories. If, however, it is deemed beneficial that the wastes ultimately be dispersed over a wide area, then the continental slope could be used as a disposal site

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

International Nuclear Information System (INIS)

Syarif Husin Lubis; Jamal Hisham Hashim; Noor Hassim Ismail; Salmaan Hussain Inayat Hussain

2002-01-01

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)

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

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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.

Investigation of the distal margins of the LVF/LDA environments in the northern midlatitudes of Mars.

Science.gov (United States)

Morgan, G. A.; Head, J. W., III

2008-09-01

Introduction The northern dichotomy boundary on Mars consists of an abrupt escarpment between the cratered uplands and the northern plains. The boundary is characterized by fretted valleys which divide the uplands into a series of plateaus and mesas which become progressively smaller to the north and eventually merge with the northern plains [1]. Lineated Valley Fill (LVF) and Lobate Debris Aprons (LDA) deposits are a prominent feature of the dichotomy boundary [2] and have been attributed by some [e.g., 3] to be the remains of debris-covered glaciers that were active during previous climatic regimes when snow was deposited along the dichotomy boundary [4-5]. Recent in depth analysis of LVF/LDA has been made possible by new comprehensive high-resolution data from Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter. and has revealed evidence for multiple LVF/LDA emplacement events [6-8], as well as evidence for plateau glaciation [4] and evidence that glacial conditions extended much further from the margins of the dichotomy boundary than previously thought [4]. However, remaining unexamined, however, are the regions adjacent to the current positions of the LVF/LDA deposits where one can explore the relationship between the distal landforms present there and the main bodies of LVF/LDA. We have therefore investigated an area of the northern plains directly north of a region of the dichotomy boundary where detailed studies have reported largescale integrated LVF systems >10,000 km3 in extent, that are analogous to terrestrial debris covered glacial systems [3,6-8]. Through the utilization of the most recent data sets (CTX and HiRISE) we have categorized the distinct landform assemblages associated with this area and documented the degraded nature of lobate debris aprons and related features present there. Degraded Lobate Debris Aprons All of the LDAs in the study region have troughs cut into their surface which are aligned in the same direction as the flanks of