WorldWideScience

Sample records for surface contamination measurements

  1. Optical measurements on contaminated surfaces

    Science.gov (United States)

    Bonham, T. E.; Schmitt, R. J.; Linford, R. M. F.

    1975-01-01

    A bidirectional reflectometer system was developed for in situ measurements of the changes in spectral reflectance of surfaces contaminated with films of organic materials. The system permits experiments with films of controlled thickness in an environment that simulates the thermal, radiation, and vacuum conditions of space. The mechanical and optical construction of the reflectometer are discussed in detail, and actual data curves are used to illustrate its operation and performance.

  2. Description of measurement techniques for surface contaminations

    International Nuclear Information System (INIS)

    Bourrez, E.

    2001-01-01

    The needs of evaluation of the surface contamination are numerous in the processes of production and management of radioactive waste. The market of radiation protection materials proposes a lot of devices answering to the almost all these needs. These device have however their conditions and particular limits for use. To realize correct measurements it is use the device, the technique and the methods adapted to the need, by taking into account the optimization of economical aspect. (N.C.)

  3. Measurement and removal of surface contamination

    International Nuclear Information System (INIS)

    Neider, M.; Tamberg, T.

    1990-01-01

    This is a critical reappraisal of the sampling factor which is important for indirect contamination measurement. The factor gives the radioactivity collected by means of a wipe sample as a fraction of the total loose radioactivity i.e. without firm adhesion. It is used in national and international standard specifications and stated, frequently with excessive conservatism, as 0.1. Secondly, the standard specifications for the testing and appraisal of surface materials in relation to their decontamination capacity and for testing the effect of decontamination agents hitherto bond and Co-60 and Cs-137 are to be expanded to include radioactive iodine, which is important in nuclear medicine. The selection of optimum surface materials will thus be put on an improved basis. (orig./DG) [de

  4. Automatic Measurement of Low Level Contamination on Concrete Surfaces

    International Nuclear Information System (INIS)

    Tachibana, M.; Itoh, H.; Shimada, T.; Yanagihara, S.

    2002-01-01

    Automatic measurement of radioactivity is necessary for considering cost effectiveness in final radiological survey of building structures in decommissioning nuclear facilities. The RAPID (radiation measuring pilot device for surface contamination) was developed to be applied to automatic measurement of low level contamination on concrete surfaces. The RAPID has a capability to measure contamination with detection limit of 0.14 Bq/cm2 for 60Co in 30 seconds of measurement time and its efficiency is evaluated to be 5 m2/h in a normal measurement option. It was confirmed that low level contamination on concrete surfaces could be surveyed by the RAPID efficiently compared with direct measurement by workers through its actual application

  5. Development of portable and automatic smear sampler for measuring surface contamination

    International Nuclear Information System (INIS)

    Lee, Bong Jae; Chang, S. Y.; Kim, B. H.; Kim, J. S.; Lee, H. S.; Kim, C. K.; Swol, C. W.

    2000-12-01

    In measuring radioactive contamination in radiation controlled area of nuclear facility, the technical criteria to evaluate surface contamination level and to sample by indirect method was established in this paper. Radioactive materials always present on surface within operating nuclear facilities. Because of the presence of interfering radiation field, health physicists take smear samples to monitoring surface contamination according to routine monitoring program. But there are some problems like great errors and difference of personnel. Then, to solve them, The portable and automatic smear sampling apparatus was designed and fabricated

  6. Development of portable and automatic smear sampler for measuring surface contamination

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bong Jae; Chang, S. Y.; Kim, B. H.; Kim, J. S.; Lee, H. S.; Kim, C. K.; Swol, C. W

    2000-12-01

    In measuring radioactive contamination in radiation controlled area of nuclear facility, the technical criteria to evaluate surface contamination level and to sample by indirect method was established in this paper. Radioactive materials always present on surface within operating nuclear facilities. Because of the presence of interfering radiation field, health physicists take smear samples to monitoring surface contamination according to routine monitoring program. But there are some problems like great errors and difference of personnel. Then, to solve them, The portable and automatic smear sampling apparatus was designed and fabricated.

  7. Measurement of residual radioactive surface contamination by 2-D laser heated TLD

    International Nuclear Information System (INIS)

    Jones, S.C.

    1997-06-01

    The feasibility of applying and adapting a two-dimensional laser heated thermoluminescence dosimetry system to the problem of surveying for radioactive surface contamination was studied. The system consists of a CO 2 laser-based reader and monolithic arrays of thin dosimeter elements. The arrays consist of 10,201 thermoluminescent phosphor elements of 40 micron thickness, covering a 900 cm 2 area. Array substrates are 125 micron thick polyimide sheets, enabling them to easily conform to regular surface shapes, especially for survey of surfaces that are inaccessible for standard survey instruments. The passive, integrating radiation detectors are sensitive to alpha and beta radiation at contamination levels below release guideline limits. Required contact times with potentially contaminated surfaces are under one hour to achieve detection of transuranic alpha emission at 100 dpm/100 cm 2 . Positional information obtained from array evaluation is useful for locating contamination zones. Unique capabilities of this system for survey of sites, facilities and material include measurement inside pipes and other geometrical configurations that prevent standard surveys, and below-surface measurement of alpha and beta emitters in contaminated soils. These applications imply a reduction of material that must be classified as radioactive waste by virtue of its possibility of contamination, and cost savings in soil sampling at contaminated sites

  8. Calculation of reasonable exemption levels for surface contamination by measuring overall gamma ray

    International Nuclear Information System (INIS)

    Ogino, Haruyuki; Hattori, Takatoshi

    2008-01-01

    The present regulation on surface contamination [Bq/cm 2 ] is determined from a simple radiological model for the most hazardous radionuclides (Pu-239 for alpha emitters and Sr-90 for beta emitters) and its extremely conservative model is applied for all other alpha and beta emitters. In this study, reasonable exemption levels for surface contamination are calculated for each radionuclide by adopting an original radiological dose evaluation method for surface contamination that can be applied in radiation safety, transport safety and waste safety. Furthermore, a new concept of judging the exemption by estimating the overall contamination [Bq] on the objects from the measurement of gamma ray has been designed and a reasonable value was derived. We conclude that the overall exemption levels obtained by gamma ray measurement can be one order smaller than those obtained by the conventional method for some radionuclides, such as Mn-54, Co-60, Nb-94, Cs-134, Cs-137, Eu-152 and Eu-154. (author)

  9. Development of the automatic measuring system to survey the surface contamination on equipments

    International Nuclear Information System (INIS)

    Ishizuka, Akira; Matsumura, Hidekatsu; Nawa, Takao; Yamaguchi, Seiji; Yamada, Tadashi.

    1980-01-01

    The inspection of surface contamination carried out when things are taken out of the control areas in nuclear power stations requires considerable labor and time because it is carried out manually. In order to make the inspection of surface contamination more efficiently and to standardize it, the development of an automatic inspection apparatus was carried out. This apparatus inspects the surface contamination due to radio isotopes which do not emit α-ray, and the objects to be measured are the large things with definite forms, such as boards and pipes for scaffolding. The method of measuring β-ray with a gas flow counter was adopted for the apparatus in view of the good detection sensitivity, relatively simple shielding against background, and easy conversion to surface contamination density. The measuring system was composed of the gas flow counters and a rate meter. The outline of the apparatus made for trial is explained. As the result of the performance test, the lowest detection sensitivity was 1.29 x 10 -5 μCi/cm 2 at the moving speed of an object of 1 cm/sec. The detection sensitivity is improved by the flattening of the sensitivity distribution. The evaluation of the error, the reduction of measuring time and the prevention of contamination were also made. (Kako, I.)

  10. Radioactive surface contamination monitors

    International Nuclear Information System (INIS)

    Aoyama, Kei; Minagoshi, Atsushi; Hasegawa, Toru

    1994-01-01

    To reduce radiation exposure and prevent contamination from spreading, each nuclear power plant has established a radiation controlled area. People and articles out of the controlled area are checked for the surface contamination of radioactive materials with surface contamination monitors. Fuji Electric has repeatedly improved these monitors on the basis of user's needs. This paper outlines typical of a surface contamination monitor, a personal surface contamination monitor, an article surface contamination monitor and a laundry monitor, and the whole-body counter of an internal contamination monitor. (author)

  11. Portable instrumentation for quantitatively measuring radioactive surface contaminations, including 90Sr

    International Nuclear Information System (INIS)

    Brodzinski, R.L.

    1983-10-01

    In order to measure the effectiveness of decontamination efforts, a quantitative analysis of the radiocontamination is necessary, both before and after decontamination. Since it is desirable to release the decontaminated material for unrestricted use or disposal, the assay equipment must provide adequate sensitivity to measure the radioactivity at or below the release limit. In addition, the instrumentation must be capable of measuring all kinds of radiocontaminants including fission products, activation products, and transuranic materials. Finally, the survey instrumentation must be extremely versatile in order to assay the wide variety of contaminated surfaces in many environments, some of which may be extremely hostile or remote. This communication describes the development and application of portable instrumentation capable of quantitatively measuring most transuranics, activation products, and fission products, including 90 Sr, on almost any contaminated surface in nearly any location

  12. Evaluation of surface contamination based on certifiably traceable, internationally accreditable measurements

    International Nuclear Information System (INIS)

    Whitlock, G.D.

    1992-01-01

    National Accreditation and Measurement Service (NAMAS) adopted by the EUROMET agreement requires that the calibration of monitoring instruments be traceable internationally with the objective that radiation hazard assessment be improved. This objective is achieved for Tritium surface contamination by employing calibration sources and evaluation methods which comply with ISO standards including the measurement of activity removable by Volatilization as well as dust. Consideration should be given to organic binding of tritium in the skin with its implications in the event of litigation. (author)

  13. Experimental analysis on removal factor of smear method in measurement of surface contamination

    International Nuclear Information System (INIS)

    Sugiura, Nobuyuki; Taira, Junichi; Takenaka, Keisuke; Yamanaka, Kazuo; Sugai, Kenji; Kosako, Toshiso

    2007-01-01

    The smear test is one of the important ways to measure surface contamination. The loose contamination under the high background radiation, which is more significant in handling non-sealed radioisotopes, can be evaluated by this method. The removal factor is defined as the ratio of the activity removed from the surface by one smear to the whole activity of the removable surface contamination. The removal factor is greatly changed by the quality and condition of surface materials. In this study, the values of removal factor at several typical surface conditions were evaluated experimentally and the practical application of those values was considered. It is required the smear should be pressed by moderate pressure when wiping the surface. The pressure from 1.0 kg to 1.5 kg per filter paper was recommended. The removal factor showed lower value in wiping by the pressure below 1.0 kg. The value of 0.5 for the removal factor could be applied to the smooth surface of linoleum, concrete coated with paint or epoxy resin, stainless steel and glass with the statistical allowance. (author)

  14. The accuracy of surface-contamination measurements; survey of UK hospitals, 1986

    International Nuclear Information System (INIS)

    Woods, M.J.

    1987-01-01

    In response to a number of concerns expressed at both national and international levels, the National Physical Laboratory (NPL) conducted a survey of UK hospitals and associated Regional Radiation Protection Services. Sources of surface contamination were distributed and participants were requested to measure these and interpret the relevant responses in terms of emission and activity per unit area. The analysis of the returns demonstrates that the vast majority of results was significantly in error and that the quality of radiation protection may be impaired. (author)

  15. Optical Interferometry with Flexible Coherent Fiber Bundle for Measuring Deposits or Contamination on Surfaces and Inside Tubes

    Data.gov (United States)

    National Aeronautics and Space Administration — A new measuring/cleaning method for closed surfaces (pipes) applicable to removing contaminants (oil films, fungus, rust) from NASA instruments and spacecraft is...

  16. Measurements of the spatial distribution of tritium in air above a chronically contaminated surface

    International Nuclear Information System (INIS)

    Workman, W.J.G.; Davis, P.A.; Wood, M.J.; Barry, P.J.

    1993-01-01

    Tritium in air (HTO) concentrations were measured over a 13 month period above a surface that is chronically contaminated by tritium-bearing groundwater from a waste management area. The measurements were made using passive diffusion samplers, which were sited at six locations (about 100 m apart) at 0.15, 0.9, and 1.8 m above ground level. The diffusion samplers were compact, sampled at a known rate, and required no external power source. They are ideal for remote locations and require a minimum of effort to collect and analyze the data. HTO-in-air concentration peaked in the summer at 500-1500 Bq.m -3 and decreased in the winter to 1-120 Bq.m -3 . In general, concentration decreased with height above ground level, implying that HTO is being lost from the surface to the atmosphere. The flux of tritium to the atmosphere must, therefore, be taken into account to estimate the tritium mass balance for a contaminated area. (Author) 3 figs., 5 tabs., 10 refs

  17. Surface soil contamination standards

    International Nuclear Information System (INIS)

    Boothe, G.F.

    1979-01-01

    The purpose of this document is to define surface soil contamination limits for radioactive materials below which posting, restrictions and environmental controls are not necessary in order to protect personnel and the environment. The standards can also be used to determine if solid waste or other material is contaminated relative to disposal requirements. The derivation of the standards is given

  18. Absorption and backscatter of internal conversion electrons in the measurements of surface contamination of 137Cs

    International Nuclear Information System (INIS)

    Yunoki, A.; Kawada, Y.; Yamada, T.; Unno, Y.; Sato, Y.; Hino, Y.

    2013-01-01

    We measured 4π and 2π counting efficiencies for internal conversion electrons (ICEs), gross β-particles and also β-rays alone with various source conditions regarding absorber and backing foil thickness using e-X coincidence technique. Dominant differences regarding the penetration, attenuation and backscattering properties among ICEs and β-rays were revealed. Although the abundance of internal conversion electrons of 137 Cs- 137 Ba is only 9.35%, 60% of gross counts may be attributed to ICEs in worse source conditions. This information will be useful for radionuclide metrology and for surface contamination monitoring. - Highlights: • Counting efficiencies for internal conversion electrons from 137 Cs were measured, and compared with those for β-rays. • Electron-X coincidence technique was employed. • A thin NaI(Tl) scintillation detector was used for X-ray detection. • Backscattering fractions of electrons and beta particles were studied by similar experiments

  19. Development of inspection techniques for quantitatively measuring surface contamination on SRM hardware

    Science.gov (United States)

    Law, R. D.

    1989-01-01

    A contaminant is any material or substance which is potentially undesirable or which may adversely affect any part, component, or assembly. Contamination control of SRM hardware surfaces is a serious concern, for both Thiokol and NASA, with particular concern for contaminants which may adversely affect bonding surfaces. The purpose of this study is to develop laboratory analytical techniques which will make it possible to certify the cleanliness of any designated surface, with special focus on particulates (dust, dirt, lint, etc.), oils (hydrocarbons, silicones, plasticizers, etc.), and greases (HD-2, fluorocarbon grease, etc.). The hardware surfaces of concern will include D6AC steel, aluminum alloys, anodized aluminum alloys, glass/phenolic, carbon/phenolic, NBR/asbestos-silica, and EPDM rubber.

  20. Some problems in calibrating surface contamination meters

    International Nuclear Information System (INIS)

    Chen Zigen; LI Xingyuan; Shuai Xiaoping.

    1984-01-01

    It is necessary that instruments are calibrated accurately in order to obtain reliable survey data of surface contamination. Some problems in calibrating surface contamination meters are expounded in this paper. Measurement comparison for beta surface contamination meters is organized within limited scope, thus survey quality is understood, questions are discovered, significance of calibration is expounded further. (Author)

  1. Evaluation of the contribution of contamination of radiotherapy room surfaces in the measure of exposure rate of radioiodine therapy patients

    International Nuclear Information System (INIS)

    Campos, Rafael Ferreira

    2015-01-01

    The contamination of radiotherapy room surfaces is significant and the measures of patient exposure rate are held on the fourth dependencies, relevant questions are raised: the background radiation of the room stay high due to surface contamination, may interfere with the rate of patient exposure at the time of its release? The monitoring site is important to determine whether the patient will be released? The value of the deal activity and the clinical condition of the patient may increase the contamination, influencing the monitoring results? This paper aims to conduct a quantitative analysis of surface contamination of the contribution of therapeutic room at the time is monitored exposure rate from inpatient. Measurements were made regarding the hospitalization of 32 patients with different doses administered activity, age and of both genders. The measurements were performed in the therapeutic rooms at the hospital Brotherhood Santa Casa de Misericordia de Sao Paulo. Exposure rate measurements were performed at the center of the room at 1 meter of the patient on the day of its release. After his release and prior to decontamination, measurements were performed at predetermined landmarks within the therapeutic room. The results revealed that on average background radiation, high due to surface contamination contributes only 2% of the patient dose rate. It can be considered that even with influence of contamination of surfaces, this is insignificant to determine if the patient may or may not be released. This study suggests that the site in which monitoring occurs exposure rate of the patient should not be decisive for liberation thereof. (author)

  2. Fluorescence Imaging Reveals Surface Contamination

    Science.gov (United States)

    Schirato, Richard; Polichar, Raulf

    1992-01-01

    In technique to detect surface contamination, object inspected illuminated by ultraviolet light to make contaminants fluoresce; low-light-level video camera views fluorescence. Image-processing techniques quantify distribution of contaminants. If fluorescence of material expected to contaminate surface is not intense, tagged with low concentration of dye.

  3. Comparison of surface contamination monitors for in vivo measurement of {sup 131}I in thyroid

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, S.M.; Dantas, A.L.A.; Dantas, B.M., E-mail: salomao.marques@ymail.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The routine handling of radiopharmaceuticals in nuclear medicine represents a significant risk of internal exposure to the staff. The IAEA recommends the implementation of monitoring plans for all workers subject to a risk of exposures above 1 mSv per year. However, in Brazil, such recommendation is practically unfeasible due to the lack of a sufficient number of qualified internal dosimetry services over the country. This work presents an alternative based on a simple and inexpensive methodology aimed to perform in-vivo monitoring of {sup 131}I in thyroid using portable surface contamination probes. All models evaluated showed suitable sensitivity for such application. (author)

  4. Comparison of surface contamination monitors for in vivo measurement of 131I in thyroid

    International Nuclear Information System (INIS)

    Oliveira, S.M.; Dantas, A.L.A.; Dantas, B.M.

    2015-01-01

    The routine handling of radiopharmaceuticals in nuclear medicine represents a significant risk of internal exposure to the staff. The IAEA recommends the implementation of monitoring plans for all workers subject to a risk of exposures above 1 mSv per year. However, in Brazil, such recommendation is practically unfeasible due to the lack of a sufficient number of qualified internal dosimetry services over the country. This work presents an alternative based on a simple and inexpensive methodology aimed to perform in-vivo monitoring of 131 I in thyroid using portable surface contamination probes. All models evaluated showed suitable sensitivity for such application. (author)

  5. Surface contamination technology in decommissioning of nuclear fuel cycle

    International Nuclear Information System (INIS)

    Ishiguro, Hideharu

    2012-01-01

    Surface contamination measurement is the most basic technology in radiation control of the nuclear and radiation facilities. Loose surface contamination causes internal exposure through airborne contamination. Surface contamination measurement is recently more important in the waste management such as confirmation of decontamination factor, contamination survey of carried-out materials from radioactive control area, and application of clearance level. This report describes the base of surface contamination standards, meaning of contamination in decommissioning, relationship between clearance level and surface contamination, and current technology of surface contamination measurement. (author)

  6. Evaluation of Unfixed Tritium Surface Contamination

    International Nuclear Information System (INIS)

    Postolache, C.; Matei, Lidia

    2005-01-01

    Surface unfixed radioactive contamination represents the amount of surface total radioactive contamination which can be eliminated by pure mechanical processes. This unfixed contamination represents the main risk factor for contamination of the personnel which operates in tritium laboratories. Unfixed contamination was determined using sampling smears type FPCSN-PSE-AA. Those FPCSN-PSE-AA smears are disks of expanded polystyrene which contain acrylic acid fragments superficially grafted. Sampling factor was determinated by contaminated surface wiping with moisten smears in 50 μL butylic alcohol and activity measuring at liquid scintillation measuring device. Sampling factor was determined by the ratio between measured activity and initially real conventional activity. The sampling factor was determined for Tritium Laboratory existent surfaces: stainless steel, aluminum, glass, ceramics, linoleum, washable coats, epoxy resins type ALOREX LP-52.The sampling factors and the reproducibility were determined in function of surface nature

  7. Hydrogen Contamination of Niobium Surfaces

    International Nuclear Information System (INIS)

    Viet Nguyen-Tuong; Lawrence Doolittle

    1993-01-01

    The presence of hydrogen is blamed for dramatic reductions in cavity Q's. Hydrogen concentration is difficult to measure, so there is a great deal of Fear, Uncertainty, and Doubt (FUD) associated with the problem. This paper presents measurements of hydrogen concentration depth profiles, commenting on the pitfalls of the methods used and exploring how material handling can change the amount of hydrogen in pieces of niobium. Hydrogen analysis was performed by a forward scattering experiment with Helium used as the primary beam. This technique is variously known as FRES (Forward Recoil Elastic Scattering), FRS, HFS (Hydrogen Forward Scattering), and HRA (Hydrogen Recoil Analysis). Some measurements were also made using SIMS (Secondary Ion Mass Spectrometry). Both HFS and SIMS are capable of measuring a depth profile of Hydrogen. The primary difficulty in interpreting the results from these techniques is the presence of a surface peak which is due (at least in part) to contamination with either water or hydrocarbons. With HFS, the depth resolution is about 30 nm, and the maximum depth profiled is about 300 nm. (This 10-1 ratio is unusually low for ion beam techniques, and is a consequence of the compromises that must be made in the geometry of the experiment, surface roughness, and energy straggling in the absorber foil that must be used to filter out the forward scattered helium.) All the observed HFS spectra include a surface peak which includes both surface contamination and any real hydrogen uptake by the niobium surface. Some contamination occurs during the analysis. The vacuum in the analysis chamber is typically a few times 10(sup -6) torr, and some of the contamination is in the form of hydrocarbons from the pumping system. Hydrocarbons normally form a very thin (less than a monolayer) film which is in equilibrium between arrival rate and the evaporation rate. In the presence of the incoming ion beam, however, these hydrocarbons crack on the surface into non

  8. Examination of a measuring method for fallout radioactivity released by the accident of the Fukushima Dai-ichi NPS. Surface contamination measurement

    International Nuclear Information System (INIS)

    Yoshii, Taiki; Kawasaki, Satoru

    2013-08-01

    Radioactive nuclides were released in the atmosphere by the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Station in March, 2011, and they are detected on the materials that had no artificial radioactive nuclides before the accident. Confronted with this situation, NISA issued a guideline titled 'A guideline regarding treatment of materials in nuclear facilities considering the influence of fallout released from the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Station' on March 30, 2012. Nuclear Regulatory Authority refers to applying the existing bylaw until the time to make decision of the updated bylaw. The guideline shows that after judging whether there is the influence of fallout or not, the conventional clearance and NR systems can be used when there is no influence of fallout. On the other hand, the special treatment is required when it is judged that there is the influence. This report describes a specific example of measuring method to evaluate the influence of fallout, in case of surface contamination. This report focused surface contamination of flat object as target. Preliminary investigation shows that the distribution of surface contamination due to fallout is near to lognormal distribution. Therefore, the sampling measurement can be adopted. The average surface contamination of target is decided from sampling data by using 90% upper confidence limit of Chebyshev inequality. Also, the minimum sampling number is decided. The evaluation of the influence of fallout is judged from the result of surface contamination measurement, weight of target and surface area of target. (author)

  9. Redispersion of indoor surface contamination: a review

    International Nuclear Information System (INIS)

    Sansone, E.B.; Slein, M.W.

    1978-01-01

    The importance of surface contamination as a potential source of exposure to hazardous materials is discussed. Data from the literature concerning the resuspension of indoor surface contamination are presented. Reported procedures for quantitating surface contamination are compared. It is suggested that, despite its limitations, surface contamination monitoring may be useful in estimating potential risks from hazardous materials. (Auth.)

  10. Location and area measurement of rock and groundwater oil contamination by surface methods

    Energy Technology Data Exchange (ETDEWEB)

    Svoma, J; Muzikar, R [ed.

    1978-01-01

    Non-destructive methods of detecting oil spills are reviewed. Geobotanical and geophysical electrical methods have had a long tradition in geological prospecting; at the present time they can be applied, in principle, to search for and to delineate oil spills. Photography is in its early stage of research in order to establish its practical use in detecting oil products. While substantial problems are not to be expected when applying infrared color photography do detect gaseous hydrocarbons, the problem of the feasibility of photoindications of pollutions caused by liquid hydrocarbons remains unsolved. High-quality spectrophotometers, spectroradiometers and infrared thermal scanners are too expensive to be available at each of the prospecting organizations. It seems to be more advantageous to equip one laboratory with peak instrumentation allowing to accomplish the basic spectrometric and thermometric measurements. Of the techniques not tested so far, radar, contactless thermometry or microseismics can be of importance for locating the presence of oil under ground. The application of nonphotographic remote sensing from satellites does not seem probable so far.

  11. Monitoring of surface and airborne contamination

    Energy Technology Data Exchange (ETDEWEB)

    Pradeep Kumar, K S [Bhabha Atomic Research Centre, Bombay (India)

    1997-06-01

    Indian nuclear energy programme aims at total safety in all activities involved in the entire fuel cycle for the occupational workers, members of the public and the environment as a whole. Routine radiation monitoring with clearly laid out procedures are followed for ensuring the safety of workers and public. Radiation monitoring carried out for the nuclear installations comprises of process monitoring, monitoring of effluent releases and also of the radiation protection monitoring of the individuals, work place and environment. Regulations like banning of smoking and consumption of food and drink etc. reduces the risk of direct ingestion even if inadvertent spread of contamination takes place. Though limit of transportable surface contamination is prescribed, the health physicists always follow a ``clean on swipe`` philosophy which compensates any error in the measurement of surface contamination. In this paper, the following items are contained: Necessity of contamination monitoring, accuracy required in the calibration of surface contamination monitors, methodology for contamination monitoring, air monitoring, guidelines for unrestricted release of scrap materials, and problems in contamination monitoring. (G.K.)

  12. OPERATIONAL LIMITATIONS FOR DEMOLITION OF A HIGHLY ALPHA CONTAMINATED BUILDING MODLES VERSUS MEASURED AIR & SURFACE ACTIVITY CONCENTRATIONS

    Energy Technology Data Exchange (ETDEWEB)

    LLOYD, E.R.

    2006-11-02

    The demolition of a facility historically used for processing and handling transuranic materials is considered. Residual alpha emitting radionuclide contamination poses an exposure hazard if released to the local environment during the demolition. The process of planning for the demolition of this highly alpha contaminated building, 232-Z, included a predemolition modeling analysis of potential exposures. Estimated emission rates were used as input to an air dispersion model to estimate frequencies of occurrence of peak air and surface exposures. Postdemolition modeling was also conducted, based on the actual demolition schedule and conditions. The modeling results indicated that downwind deposition is the main operational limitation for demolition of a highly alpha-contaminated building. During the demolition of 232-Z, airborne radiation and surface contamination were monitored. The resultant non-detect monitoring results indicate a significant level of conservatism in the modeled results. This comparison supports the use of more realistic assumption in the estimating emission rates. The resultant reduction in modeled levels of potential exposures has significant implications in terms of the projected costs of demolition of such structures.

  13. Measurement of surface contamination by certain antineoplastic drugs using high-performance liquid chromatography: applications in occupational hygiene investigations in hospital environments.

    Science.gov (United States)

    Rubino, F M; Floridia, L; Pietropaolo, A M; Tavazzani, M; Colombi, A

    1999-01-01

    Within the context of continuing interest in occupational hygiene of hospitals as workplaces, the authors report the results of a preliminary study on surface contamination by certain antineoplastic drugs (ANDs), recently performed in eight cancer departments of two large general hospitals in Milan, Italy. Since reliable quantitative information on the exposure levels to individual drugs is mandatory to establish a strong interpretative framework for correctly assessing the health risks associated with manipulation of ANDs and rationally advise intervention priorities for exposure abatement, two automated analytical methods were set up using reverse-phase high-performance liquid chromatography for the measurement of contamination by 1) methotrexate (MTX) and 2) the three most important nucleoside analogue antineoplastic drugs (5-fluorouracil 5FU, Cytarabin CYA, Gemcytabin GCA) on surfaces such as those of preparation hoods and work-benches in the pharmacies of cancer wards. The methods are characterized by short analysis time (7 min) under isocratic conditions, by the use of a mobile phase with a minimal content of organic solvent and by high sensitivity, adequate to detect surface contamination in the 5-10 micrograms/m2 range. To exemplify the performance of the analytical methods in the assessment of contamination levels from the target analyte ANDs, data are reported on the contamination levels measured on various surfaces (such as on handles, floor surfaces and window panes, even far from the preparation hood). Analyte concentrations corresponding to 0.8-1.5 micrograms of 5FU were measured on telephones, 0.85-28 micrograms/m2 of CYA were measured on tables, 1.2-1150 micrograms/m2 of GCA on furniture and floors. Spillage fractions between 1-5% of the used ANDs (daily use 5FU 7-13 g; CYA 0.1-7.1 g; GCA 0.2-5 g) were measured on the disposable polythene-backed paper cover sheet of the preparation hood.

  14. Radiative Transfer Model for Contaminated Rough Surfaces

    Science.gov (United States)

    2013-02-01

    reflectance of potassium chlorate and ammonium nitrate contaminated surfaces in mid-wavelength and long-wavelength infrared for detection. Our framework...obtained excellent or good results for lab measurements of potassium chlorate on most aluminum surfaces; however, ammonium nitrate on painted aluminum...misidentify potassium chlorate as ammonium nitrate and vice versa). We also observed moderate success on field data. 15. SUBJECT TERMS radiative

  15. Contamination of optical surfaces in Earth orbit

    Science.gov (United States)

    Kinser, Donald L.; Weller, Robert A.; Mendenhall, M. H.; Wiedlocher, D. E.; Nichols, R.; Tucker, D.; Whitaker, A.

    1992-01-01

    Glass and glass ceramic samples exposed to the low earth orbit environment for approximately 5.5 years on the Long Duration Exposure Facility (LDEF) were found to display limited degradation in optical transmission. Commercial optical quality fused silica samples display decreases in transmission in the 200 to 400 nm wavelength region, and this degradation appears to be a consequence of surface contamination. The contamination, found only on internal surfaces of samples, was measured by medium energy backscattering spectrometry and found to be primarily carbon. Additional thin film contamination by a species with atomic mass near 64, which was present at the level of about 8 x 10 exp 14/sq. cm has not been identified. These observations are consistent with the interpretation that organic binders used in the black absorbing paint (Chem Glaze Z-306) inside the sample holding tray were concentrated in the vicinity of the samples and photolytically cracked by solar UV radiation. The resulting decomposition products were deposited on the interior sample surface and gave rise to the optical transmission loss. No detectable contamination was observed on the external or space exposed surface of the samples. No measurable damage was detected which could be attributed to the direct action of gamma or UV radiation on the glass samples. These results emphasize the need for special precautions in the preparation of spacecraft carrying precision optical components on long duration missions.

  16. False negative rate and other performance measures of a sponge-wipe surface sampling method for low contaminant concentrations.

    Energy Technology Data Exchange (ETDEWEB)

    Einfeld, Wayne; Krauter, Paula A.; Boucher, Raymond M.; Tezak, Mathew; Amidan, Brett G. (Pacific Northwest National Laboratory, Richland, WA); Piepel, Greg F. (Pacific Northwest National Laboratory, Richland, WA)

    2011-05-01

    Recovery of spores from environmental surfaces is known to vary due to sampling methodology, techniques, spore size and characteristics, surface materials, and environmental conditions. A series of tests were performed to evaluate a new, validated sponge-wipe method. Specific factors evaluated were the effects of contaminant concentrations and surface materials on recovery efficiency (RE), false negative rate (FNR), limit of detection (LOD) - and the uncertainties of these quantities. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show a roughly linear dependence of surface roughness on RE, where the smoothest surfaces have the highest mean RE values. REs were not influenced by the low spore concentrations tested (3 x 10{sup -3} to 1.86 CFU/cm{sup 2}). The FNR data were consistent with RE data, showing a trend of smoother surfaces resulting in higher REs and lower FNRs. Stainless steel generally had the lowest mean FNR (0.123) and plastic had the highest mean FNR (0.479). The LOD{sub 90} varied with surface material, from 0.015 CFU/cm{sup 2} on stainless steel up to 0.039 on plastic. Selecting sampling locations on the basis of surface roughness and using roughness to interpret spore recovery data can improve sampling. Further, FNR values, calculated as a function of concentration and surface material, can be used pre-sampling to calculate the numbers of samples for statistical sampling plans with desired performance, and post-sampling to calculate the confidence in characterization and clearance decisions.

  17. Derived limits for surface contamination

    CERN Document Server

    Wrixon, A D; Linsley, G S; White, D F

    1979-01-01

    Derived limits (DLs) for surface contamination were first established for use in the nuclear energy industry where a wide variety of radionuclides is encountered. They were later used in factories, hospitals, and universities, where the radionuclides used are normally fewer in number, either known or readily identifiable, and often of low toxicity. In these situations the current limits are frequently over-restrictive. This report describes a reassessment of the values in the light of more recent information on the possible pathways of exposure and the dose equivalent limits given in ICRP Publication 26. The reassessment is prompted also by the introduction of SI units. The results of the reassessment are used to produce a classification of DLs for all radionuclides for active and inactive area surfaces and for skin.

  18. Intercomparison measurements of surface soil contamination with in-situ gamma ray spectrometry. Pt.1. Artificial radionuclides

    International Nuclear Information System (INIS)

    Winkelmann, I.

    1994-01-01

    This intercomparison program was performed by the Federal Office of Radiation Protection in October 1993. It includes seven laboratory teams from five countries and is applied on a pasture in southern Germany having an undisturbed soil profile. The location was chosen because of its relatively high 137 Cs-soil contamination caused by the Chernobyl accident - up to 50 kBq/m 2 . The deposition of 134 Cs and 137 Cs was determined. The comparison demonstrated a good agreement between results from different labs. Additionally, the dose rate at all marked locations was measured and compared to the dose rate of individual radionuclides calculated from the measured spectra. A relatively good agreement was obtained. It is shown that the main contribution to the total dose rate of 70 nSv/h is made by 137 Cs with a value of 5 nSv/h. 4 figs., 2 tabs., 3 refs. (orig.)

  19. Airborne iodine-125 arising from surface contamination

    International Nuclear Information System (INIS)

    Kwok, C.S.; Hilditch, T.E.

    1982-01-01

    Measurements of airborne 125 I were made during the subdivision of 740 MBq stocks of 125 I iodide solution in a hospital dispensary. Within the fume cupboard the mean airborne 125 I concentration was 3.5 +- 2.9 kBqm -3 . No airborne concentration contamination was found outside the fume cupboard during these dispensing sessions. The airborne 125 I concentration arising from deliberate surface contamination (50 μl, 3.7-6.3 MBq) of the top of a lead pot was measured at a height simulating face level at an open work bench. There was a progressive fall in airborne concentration over seven days but even then the level was still significantly above background. Measurements made with the extraction system of the fume cupboard in operation were 2-3 times lower. (U.K.)

  20. Contamination detector for inner surface of container

    International Nuclear Information System (INIS)

    Watanabe, Tadao.

    1995-01-01

    The present invention concerns a device for detecting contamination of radioactive materials on the inner surface of a vessel upon reutilizing the vessel for containing solidified radioactive wastes and transporting them. Namely, the detecting device has following functions. (1) A radiation detector detects the radioactive materials on the inner surface of the vessel. (2) A plurality of proximity switches measure the distance from the radiation detector to the wall surface of the vessel and are actuated if the distance is decreased to a predetermined value, (3) A vessel inner surface position calculation mechanism calculates the position of the inner surface of the vessel based on the information from a direction indicator and a height indicator. (4) A frontal limit detector detects the limit for allowing the radiation detector to proceed. (5) A vessel inner shape judging mechanism for judging the shape of the inner side of the vessel based on the signals from the proximity switches in a state where the frontal limit detector is operated and a vessel inner surface position signal outputted from the vessel inner surface position calculation mechanism. As a result, the shape of the inner side of the vessel can accurately be recognized, thereby improving accuracy of radiation measurement. (I.S.)

  1. Body-surface contamination monitoring preparatory to monitoring for internal contamination

    International Nuclear Information System (INIS)

    Schlueter, W.; Klucke, H.

    1980-01-01

    Measurements in the whole-body counter of the SAAS are routinely preceded by a thorough inspection of the patients for body-surface contamination to protect the sensitive counting equipment against becoming contaminated and to avoid a falsified indication of incorporated radionuclides. The measuring system employed for these examinations is described. (author)

  2. Techniques for removing contaminated concrete surfaces

    International Nuclear Information System (INIS)

    Halter, J.M.; Sullivan, R.G.

    1981-01-01

    This discussion compares various techniques that have been used to clean concrete surfaces by removing the surface. Three techniques which have been investigated by the Pacific Northwest Laboratory for removing surfaces are also described: the water cannon, the concrete spaller, and high-pressure water jet. The equipment was developed with the assumption that removal of the top 1/8 to 1/4 in. of surface would remove most of the contamination. If the contamination has gone into cracks or deep voids in the surface, the removal processes can be repeated until the surface is acceptable

  3. BIOREMEDIATION OF CONTAMINATED SURFACE SOILS

    Science.gov (United States)

    Biological remediation of soils contaminated with organic chemicals is an alternative treatment technology that can often meet the goal of achieving a permanent clean-up remedy at hazardous waste sites, as encouraged by the U.S. Environmental Protection Agency (U.S. EPA) for impl...

  4. Calibration of alpha surface contamination monitor

    International Nuclear Information System (INIS)

    Freitas, I.S.M. de; Goncalez, O.L.

    1990-01-01

    In this work, the results, as well as the methodology, of the calibration of an alpha surface contamination monitor are presented. The calibration factors are obtained by least-squares fitting with effective variance. (author)

  5. Decontamination of radioactively contaminated surfaces

    International Nuclear Information System (INIS)

    1986-10-01

    By this standard objective conditions to evaluate and test the ease of decontamination of surfaces under laboratory conditions are to be laid down. Ease of decontamination in this context denotes the summed-up effect of two material properties: a) the capacity of the material for retaining radioactive substances at its surface; b) the ease with which these substances are given off again in the course of cleaning processes. (orig./HP) [de

  6. Development of radioactive surface contamination monitor

    International Nuclear Information System (INIS)

    Hashimoto, Tadao; Hasegawa, Toru; Fukumoto, Keisuke; Ooki, Yasushi

    2008-01-01

    In the radiation facilities such as nuclear power plants, surface contamination of the people accessing or articles conveyed in and out of the radiation controlled areas is detected and monitored by installing contamination monitors at the boundary of controlled areas and uncontrolled areas against the expansion of the radioactive materials to out of the facilities. It is required for the surface contamination of articles to be tightened of control criteria as 'Guidelines for discrimination ways of nonradioactive waste (not classified as radioactive waste) generated from nuclear power plants' (hereinafter referred to as 'the Guideline') was established by the Nuclear and Industrial Safety Agency of the Ministry of Economy, Trade and Industry in August, 2005. It predicts that the control criteria of monitors other than article monitors are also tightened in the future. Fuji electric has been fabricating and delivering surface contamination detecting monitors. Now we are developing the new contamination monitor corresponding to the tightening of the control criteria. 'Large article transfer monitor', 'Clothing monitor' and 'Body surface contamination monitor' are introduced in this article. (author)

  7. Occurrence of Surface Water Contaminations: An Overview

    Science.gov (United States)

    Shahabudin, M. M.; Musa, S.

    2018-04-01

    Water is a part of our life and needed by all organisms. As time goes by, the needs by human increased transforming water quality into bad conditions. Surface water contaminated in various ways which is pointed sources and non-pointed sources. Pointed sources means the source are distinguished from the source such from drains or factory but the non-pointed always occurred in mixed of elements of pollutants. This paper is reviewing the occurrence of the contaminations with effects that occurred around us. Pollutant factors from natural or anthropology factors such nutrients, pathogens, and chemical elements contributed to contaminations. Most of the effects from contaminated surface water contributed to the public health effects also to the environments.

  8. Quantification of surface contamination: principles and applications

    International Nuclear Information System (INIS)

    Vo-Dinh, T.

    1982-01-01

    The applications discussed in this paper underscore the usefulness and versatility of molecular luminescence spectroscopy as an efficient surface detection technique. The technique can be used not only as a qualitative characterization method, but also as a quantitative analytical tool to detect trace contaminants on surfaces. Recent advances in instrumentation and methodology have expanded the applicability of surface luminescence into many new problem areas. Trace organics are emphasized here

  9. Measurement of radioactive soil contamination from the air

    International Nuclear Information System (INIS)

    Loman, A.C.; Kuile, C.R. ter; Slaper, H.

    1990-09-01

    In-situ gamma spectrometry can be used to determine the qualitative and quantitative deposition of radioactive materials on the ground surface. By applying the in-situ spectrometry method using either a helicopter or an airplane, large areas can be scanned in a short period of time. In this report the results of in-situ gamma spectroscopic measurements taken from a helicopter are described. Measurements were carried out using a single point source, a field of 36 point sources, and using the present ground contamination due to fall-out from the Chernobyl accident and atom bombs. The results of these measurements were used to determine calibration factors, which were in agreement with a calibration obtained using more simple (and less expensive) laboratory measurements in combination with flux calculations. Detection limits for the measurement of surface contamination were determined. At a height of 50 meters above the surface and using a measurement time of 2 minutes, the minimally detectable surface contamination was 1.1 kBqm -2 for a Cs-137 contamination and 2.1 kBqm -2 for I-131 contamination. Fall-out determinations based on measurements taken at a height of 50 meters were in agreement with determinations taken at a height of 1 meter, and with the results obtained measuring soil samples. The in-situ gamma spectroscopy, using helicopter or airplane, is a fast and powerful method for mapping surface contamination. (author). 13 refs.; 18 figs.; 13 tabs

  10. Evaluation of the contribution of contamination of radiotherapy room surfaces in the measure of exposure rate of radioiodine therapy patients; Avaliacao da contribuicao da contaminacao de superficies do quarto terapeutico na medida da taxa de exposicao de pacientes de radioiodoterapia

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Rafael Ferreira

    2015-07-01

    The contamination of radiotherapy room surfaces is significant and the measures of patient exposure rate are held on the fourth dependencies, relevant questions are raised: the background radiation of the room stay high due to surface contamination, may interfere with the rate of patient exposure at the time of its release? The monitoring site is important to determine whether the patient will be released? The value of the deal activity and the clinical condition of the patient may increase the contamination, influencing the monitoring results? This paper aims to conduct a quantitative analysis of surface contamination of the contribution of therapeutic room at the time is monitored exposure rate from inpatient. Measurements were made regarding the hospitalization of 32 patients with different doses administered activity, age and of both genders. The measurements were performed in the therapeutic rooms at the hospital Brotherhood Santa Casa de Misericordia de Sao Paulo. Exposure rate measurements were performed at the center of the room at 1 meter of the patient on the day of its release. After his release and prior to decontamination, measurements were performed at predetermined landmarks within the therapeutic room. The results revealed that on average background radiation, high due to surface contamination contributes only 2% of the patient dose rate. It can be considered that even with influence of contamination of surfaces, this is insignificant to determine if the patient may or may not be released. This study suggests that the site in which monitoring occurs exposure rate of the patient should not be decisive for liberation thereof. (author)

  11. Monitoring of tritium-contaminated surfaces, including skin

    Energy Technology Data Exchange (ETDEWEB)

    Surette, R A; Wood, M J

    1994-05-01

    We have examined various commercially available tritium surface contamination monitors along with different swipe media and techniques for direct and indirect (swipe) monitoring of contaminated surfaces, including skin. None of the methods or instruments evaluated were more sensitive than the swipe and liquid scintillation counting (LSC) method. Swipe measurements with open-window proportional counters were, in general, less than half as sensitive as LSC, but have the advantages of having the results available almost immediately, and no sample preparation is required. The Nuclear Measurement Corporation`s PC-55 is the most suitable instrument we tested for the analysis of routine swipe measurement. The PC-55 was about one third as sensitive as LSC when used with Ontario Hydro filter paper swipe media. Surface contamination measurement results can be obtained within minutes using the PC-55, compared to hours using LSC. The selection of swipe media for use with proportional counter-based instruments is critical. A medium that is electrically insulating can develop an electrostatic charge on its surface; this may alter the field gradient in the detector and may adversely influence the results. Although the PC-55 is sufficiently sensitive and very convenient, operational experience with the instrument is needed before recommending that it replace current LSC methods. The PC-55`s susceptibility to internal tritium contamination may limit its practical usefulness. Because of the complexity of using live animals to evaluate direct and indirect methods for assessing skin contamination, pig skin was investigated as a possible substitute. We concluded that, for the first few hours post-exposure, pig skin mimics the kinetics of animal skin that has contacted a tritium-contaminated surface. (author). 30 refs., 1 tab., 7 figs.

  12. Monitoring of tritium-contaminated surfaces, including skin

    International Nuclear Information System (INIS)

    Surette, R.A.; Wood, M.J.

    1994-05-01

    We have examined various commercially available tritium surface contamination monitors along with different swipe media and techniques for direct and indirect (swipe) monitoring of contaminated surfaces, including skin. None of the methods or instruments evaluated were more sensitive than the swipe and liquid scintillation counting (LSC) method. Swipe measurements with open-window proportional counters were, in general, less than half as sensitive as LSC, but have the advantages of having the results available almost immediately, and no sample preparation is required. The Nuclear Measurement Corporation's PC-55 is the most suitable instrument we tested for the analysis of routine swipe measurement. The PC-55 was about one third as sensitive as LSC when used with Ontario Hydro filter paper swipe media. Surface contamination measurement results can be obtained within minutes using the PC-55, compared to hours using LSC. The selection of swipe media for use with proportional counter-based instruments is critical. A medium that is electrically insulating can develop an electrostatic charge on its surface; this may alter the field gradient in the detector and may adversely influence the results. Although the PC-55 is sufficiently sensitive and very convenient, operational experience with the instrument is needed before recommending that it replace current LSC methods. The PC-55's susceptibility to internal tritium contamination may limit its practical usefulness. Because of the complexity of using live animals to evaluate direct and indirect methods for assessing skin contamination, pig skin was investigated as a possible substitute. We concluded that, for the first few hours post-exposure, pig skin mimics the kinetics of animal skin that has contacted a tritium-contaminated surface. (author). 30 refs., 1 tab., 7 figs

  13. Correlation of gamma spectrometer measurements at surface with concentrations and distributions of subsurface radium contamination: Development, verification and application of methodology

    International Nuclear Information System (INIS)

    McCallum, B.A.; Clement, C.H.; Huffman, D.; Stager, R.H.

    2000-01-01

    This work is a step forward in the investigation of data gathering principles and analysis tools for improved estimates of subsurface radium contamination concentrations and distributions using surface gamma radiation spectra. Techniques to solve the inverse problem of estimating surface gamma radiation spectra given a fully known subsurface radium distribution have been investigated and applied with success. These techniques fell into three broad categories: empirical (using laboratory and field data), analytical (using mathematical derivations of relationships), and computer simulation (using Monte-Carlo photon transport simulation methods). Methods of analyzing surface spectra to estimate certain source parameters have been studied. The most fully developed methods are those involving the ratio of the areas of two peaks of differing energy from the same radionuclide to determine the source depth. For a point source of radium and its progeny, these techniques are able to reliably estimate the source depth from a single gamma radiation spectrum taken at the surface directly above the source. The only significant uncertainties in this case are the soil density and uncertainties introduced as a result of counting statistics. Further work remains to fully achieve the goals of the larger project: to develop a comprehensive suite of tools for the improved interpretation of surface gamma radiation spectra from subsurface distributions of radium contaminated soil. (author)

  14. System for removing contaminated surface layers

    International Nuclear Information System (INIS)

    Yoshikawa, Kozo.

    1987-04-01

    The object of the present invention is to offer a new type of useful decontamination system, with which the contaminated surface layers can be removed effectively by injection of such solid microparticles. Liquid carbon dioxide is passed from a liquid carbon dioxide tank via the carbon dioxide supply line into the system for injecting solid carbon dioxide particles. Part of the liquid carbon dioxide introduced into the system is converted to solid carbon dioxide particles by the temperature drop resulting from adiabatic expansion in the carbon dioxide expansion space of the injection system. The solid carbon dioxide particles reach the injection nozzle, which is connected through the expansion space. The carbon dioxide microparticles are further cooled and accelerated by nitrogen gas injected from the nitrogen gas nozzle at the tip of the nitrogen gas supply line, which is connected to a liquid nitrogen tank. The cooled and accelerated solid carbon dioxide microparticles are injected from the injection nozzle for the solid carbon dioxide and directed against the contaminated surface to be cleaned, and, as a result, the surface contamination is removed

  15. Smears for determinations surface unfixed tritium contamination

    International Nuclear Information System (INIS)

    Postolache, Cristian; Matei, Lidia

    2003-01-01

    The present paper describes a method of obtaining expanded polystyrene with hydrophilized surface smears by radioinduced grafting of acrylic acid. The grafting was carried out by using a 60 Co γ radiation source. The variation of grafting rates as a function of dose range and absorbed dose was established. Grafting radiochemical rates were determined by radiometric methods using acrylic acid labeled with tritium as a grafting agent. The sampling coefficients and the reproducibility were analyzed as a function of the nature of the contaminated surface. (authors)

  16. MEASURING CONTAMINANT RESUSPENSION RESULTING FROM SEDIMENT CAPPING

    Science.gov (United States)

    This Sediment Issue summarizes two studies undertaken at marine sites by the National Risk Management Research Laboratory of U.S. EPA to evaluate the resuspension of surface materials contaminated with polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) b...

  17. Release of Streptomyces albus propagules from contaminated surfaces

    International Nuclear Information System (INIS)

    Gorny, R.L.; Mainelis, Gediminas; Grinshpun, Sergey A.; Willeke, Klaus; Dutkiewicz, Jacek; Reponen, Tiina

    2003-01-01

    The release of Streptomyces albus propagules from contaminated agar an ceiling tile surfaces was studied under controlled environmental condition in a newly developed aerosolization chamber. The experiments revealed tha both spores and cell fragments can be simultaneously released from the colonized surface by relatively gentle air currents of 0.3 m s -1 . A 100x increase of the air velocity can result in a 50-fold increase in the number of released propagules. The aerosolization rate depends strongly on the typ and roughness of the contaminated surface. Up to 90% of available actinomycete propagules can become airborne during the first 10 min of th release process. Application of vibration to the surface did not reveal an influence on the aerosolization process of S. albus propagules under th tested conditions. This study has shown that propagules in the fine particle size range can be released in large amounts from contaminated surfaces Measurement of the number of S. albus fragments in the vicinity of contaminated area, as an alternative to conventional air or surface sampling appears to be a promising approach for quantitative exposure assessment

  18. Direct measurements of the tile drain and groundwater flow route contributions to surface water contamination: From field-scale concentration patterns in groundwater to catchment-scale surface water quality

    International Nuclear Information System (INIS)

    Rozemeijer, J.C.; Velde, Y. van der; Geer, F.C. van; Bierkens, M.F.P.; Broers, H.P.

    2010-01-01

    Enhanced knowledge of water and solute pathways in catchments would improve the understanding of dynamics in water quality and would support the selection of appropriate water pollution mitigation options. For this study, we physically separated tile drain effluent and groundwater discharge from an agricultural field before it entered a 43.5-m ditch transect. Through continuous discharge measurements and weekly water quality sampling, we directly quantified the flow route contributions to surface water discharge and solute loading. Our multi-scale experimental approach allowed us to relate these measurements to field-scale NO 3 concentration patterns in shallow groundwater and to continuous NO 3 records at the catchment outlet. Our results show that the tile drains contributed 90-92% of the annual NO 3 and heavy metal loads. Considering their crucial role in water and solute transport, enhanced monitoring and modeling of tile drainage are important for adequate water quality management. - Direct measurements of flow route contributions to surface water contaminant loading reveal the crucial role of tile drainage for catchment-scale water and solute transport.

  19. Dosimetric system for measurement of radioactive contaminations

    International Nuclear Information System (INIS)

    Litynski, Z.; Pienkos, J.P.; Witkowski, J.; Zadrozny, S.

    1985-01-01

    A dosimetric system for personnel dosimetry and monitoring measuring a contamination without time delay and dead time is described. The system ensures many-point measurement and minimalization of background radiation influence. 1 fig. (A.S.)

  20. Decontamination of plutonium-contaminated surfaces

    International Nuclear Information System (INIS)

    Bertrand, J.; Clouet d'Orval, Ch.; Tachon, J.

    1958-01-01

    The measure of the neutron distribution in the core of 'Proserpine', by means of activation detectors, requires no contact between the plutonium sulfate solution and the detectors. These detectors are put into PVC or polyethylene bags. This report describes the process used to decontaminate these bags. A washing by nitric acid followed by coating with plexiglass is kept, with this process we have no contamination on the detectors. (author) [fr

  1. A consideration on internal dose evaluation and intervention based on a surface contamination concept

    International Nuclear Information System (INIS)

    Yasuda, H.

    1997-01-01

    Long-term radiation doses received by the inhabitants after the Chernobyl accident have been evaluated according to the surface contamination levels on the ground surface. The health effects have also been discussed by comparison between the surface-contaminated area and the uncontaminated control area. Selected protective measures were carried out in accordance with the contamination level of surface soil. These have been based on the 'surface contamination concept' which assumes that the radiation risk to inhabitants is proportional to the level of ground-surface contamination. The observations collected in regions around Chernobyl, however, show that the internal radiation doses to the inhabitants poorly correlate with the surface contamination level. This fact poses a question on the suitability of dose evaluations and interventions based on this concept

  2. Synthesis of present methods of surface contamination detection (skin, clothes, laboratories)

    International Nuclear Information System (INIS)

    Joudrier, P.

    1983-01-01

    The signification of the term ''contamination'' is briefly recalled. To measure the levels of contamination, there are only two methods: the direct method and the indirect method. Finally, the recent improvements in the surface contamination detection field are shortly reviewed [fr

  3. Micrometeorological methods for measurements of mercury emissions over contaminated soils

    International Nuclear Information System (INIS)

    Kim, K.H.; Lindberg, S.E.; Hanson, P.J.; Owens, J.; Myers, T.P.

    1993-01-01

    As part of a larger study involving development and application of field and laboratory methods (micrometeorological, dynamic enclosure chamber, and controlled laboratory chamber methods) to measure the air/surface exchange of Hg vapor, we performed a series of preliminary measurements over contaminated soils. From March--April 1993, we used the modified Bowen ratio (MBR) method to measure emission rates of mercury over a floodplain contaminated with mercury near Oak Ridge, TN. The mercury emission rates measured from contaminated EFPC soils using the MBR method during early spring show that (1) in all cases, the contaminated soils acted as a source of mercury to the atmosphere with source strengths ranging from 17 to 160 ng m -2 h -1 ; and (2) the strengths of mercury emissions can be greatly influenced by the combined effects of surface soil temperature, residence time of air masses over the source area, and turbulence conditions. The mercury fluxes measured in a controlled flow chamber indicate that contaminated soils can exhibit up to an order of magnitude higher emission rates of Hg under conditions of elevated soil temperature, soil structure disturbance, and high turbulence. Mercury emissions from contaminated soils exceeded emissions from background soils by one to two orders of magnitude

  4. Measurement of contamination by 241Am

    International Nuclear Information System (INIS)

    Hemmingsen, L.B.S.

    1991-08-01

    In relation to the fact that four employees at the Danish Isotope Center who had regularly cleaned the smoke detectors used for control measurements were found to be contaminated with 241 Am, the aim was to investigate the suitability of the Phoswich detector system for measurement of contamination of humans by 241 Am. It was also wished to compare this measuring method with other selected ones. The measurement results are presented in detail. It was found that measurements taken on the cranium with the Phoswich detectors were more suitable for measurement of contamination by 241 Am than the use of a Ge detector on the liver, - because of the first-named method's greater degree of measuring efficiency, (0.013 cps/Bq compared with 0.0001 cps/Bq in the case of Ge detector measurement) and lower minimum detectable activity in relation to that activity that was measured on A1 (one of the employees). It was found that Phoswich-detector measurement and measuring of urine samples supplemented each other in a satisfactory way. The Phoswich detector enables a quick measurement of the degree of seriousness of the contamination of a person and a relatively accurate determination of the calculated intake of contamination which has a size of at least twice the annual limit of intake size. Measurements of urine samples enable smaller amounts of contamination to be revealed, but this takes ca. 32 weeks and is less accurate than Phoswich measurement especially if a long time has elapsed after the intake. (AB) (34 refs.)

  5. Automation system for tritium contaminated surface monitoring

    International Nuclear Information System (INIS)

    Culcer, Mihai; Iliescu, Mariana; Curuia, Marian; Raceanu, Mircea; Enache, Adrian; Stefanescu, Ioan; Ducu, Catalin; Malinovschi, Viorel

    2005-01-01

    The low energy of betas makes tritium difficult to detect. However, there are several methods used in tritium detection, such as liquid scintillation and ionization chambers. Tritium on or near a surface can be also detected using proportional counter and, recently, solid state devices. The paper presents our results in the design and achievement of a surface tritium monitor using a PIN photodiode as a solid state charged particle detector to count betas emitted from the surface. That method allows continuous, real-time and non-destructively measuring of tritium. (authors)

  6. Strippable gel for decontamination of contaminated metallic surfaces

    International Nuclear Information System (INIS)

    Banerjee, D.; Sandhya, U.; Khot, S.A.; Srinivas, C.; Wattal, P.K.

    2013-01-01

    Periodic decontamination of radioactive laboratories including fume hoods, glove boxes and all surfaces used for handling, processing and transporting radioactive materials is mandatory in all nuclear installations as this reduces spread of contamination and decreases total man rem exposure. Conventionally, chemical decontaminating agents or surfactant solutions are used for this purpose. However, this approach leads to generation of large volume of secondary radioactive waste. The use of strippable gel is an attractive alternative with low secondary waste generation particularly where removal of loose or weakly fixed contamination is necessary and also when the decontaminated material are to be reused, for e.g. decontamination of fume hoods, glove boxes, transport casks, spent fuel storage racks, control rod drive transport containers etc. Literature on gel formulations is scarce and mostly in the patent form. The sustained effort on gel formulation development has resulted in a basic gel formulation. The gel is a highly viscous water-based organic polymer, particularly suitable for application on vertical surfaces including difficult to reach metallic surfaces of complex geometry and not just limited to horizontal surfaces. The gel can be easily applied on contaminated surfaces by brushing or spraying. Curing of the gel is complete within 16-24 hours under ambient conditions and can then be removed by peeling as a dry sheet. While curing, the contaminants are trapped in gel either physically or chemically depending upon the nature of the contaminant. Salient features of cured gel include that it is water soluble and can be disposed off after immobilization in cement. Decontamination performance of the gel was initially evaluated by applying it on SS planchettes contaminated with known amount of radionuclides such as Cs(I), Co(II) and Ce(III). The measured decontamination factor was found to be in the range of 50-500, lowest for Ce(III) and highest for Co

  7. Calibration and verification of surface contamination meters --- Procedures and techniques

    International Nuclear Information System (INIS)

    Schuler, C; Butterweck, G.; Wernli, C.; Bochud, F.; Valley, J.-F.

    2007-03-01

    A standardised measurement procedure for surface contamination meters (SCM) is presented. The procedure aims at rendering surface contamination measurements to be simply and safely interpretable. Essential for the approach is the introduction and common use of the radionuclide specific quantity 'guideline value' specified in the Swiss Radiation Protection Ordinance as unit for the measurement of surface activity. The according radionuclide specific 'guideline value count rate' can be summarized as verification reference value for a group of radionuclides ('basis guideline value count rate'). The concept can be generalized for SCM of the same type or for SCM of different types using he same principle of detection. A SCM multi source calibration technique is applied for the determination of the instrument efficiency. Four different electron radiation energy regions, four different photon radiation energy regions and an alpha radiation energy region are represented by a set of calibration sources built according to ISO standard 8769-2. A guideline value count rate representing the activity per unit area of a surface contamination of one guideline value can be calculated for any radionuclide using instrument efficiency, radionuclide decay data, contamination source efficiency, guideline value averaging area (100 cm 2 ), and radionuclide specific guideline value. n this way, instrument responses for the evaluation of surface contaminations are obtained for radionuclides without available calibration sources as well as for short-Iived radionuclides, for which the continuous replacement of certified calibration sources can lead to unreasonable costs. SCM verification is based on surface emission rates of reference sources with an active area of 100 cm 2 . The verification for a given list of radionuclides is based on the radionuclide specific quantity guideline value count rate. Guideline value count rates for groups of radionuclides can be represented within the maximum

  8. Analysis of surface contaminants on beryllium and aluminum windows

    International Nuclear Information System (INIS)

    Gmur, N.F.

    1987-06-01

    An effort has been made to document the types of contamination which form on beryllium window surfaces due to interaction with a synchrotron radiation beam. Beryllium windows contaminated in a variety of ways (exposure to water and air) exhibited surface powders, gels, crystals and liquid droplets. These contaminants were analyzed by electron diffraction, electron energy loss spectroscopy, energy dispersive x-ray spectroscopy and wet chemical methods. Materials found on window surfaces include beryllium oxide, amorphous carbon, cuprous oxide, metallic copper and nitric acid. Aluminum window surface contaminants were also examined

  9. Developments in surface contamination and cleaning fundamentals and applied aspects

    CERN Document Server

    Kohli, Rajiv

    2015-01-01

    Developments in Surface Contamination and Cleaning, Vol. 1: Fundamentals and Applied Aspects, Second Edition, provides an excellent source of information on alternative cleaning techniques and methods for characterization of surface contamination and validation. Each volume in this series contains a particular topical focus, covering the key techniques and recent developments in the area. This volume forms the heart of the series, covering the fundamentals and application aspects, characterization of surface contaminants, and methods for removal of surface contamination. In addition, new cleaning techniques effective at smaller scales are considered and employed for removal where conventional cleaning techniques fail, along with new cleaning techniques for molecular contaminants. The Volume is edited by the leading experts in small particle surface contamination and cleaning, providing an invaluable reference for researchers and engineers in R&D, manufacturing, quality control, and procurement specific...

  10. Bonding of radioactive contamination. IV. Effect of surface finish

    International Nuclear Information System (INIS)

    Rankin, W.N.

    1983-01-01

    The mechanisms by which radioactive contamination would be bonded to a DWPF canister are being investigated. Previous investigations in this series have examined the effects of temperature, oxidation before contamination, and atmosphere composition control on the bonding of contamination. This memorandum describes the results of tests to determine the effect of special surface finishes on the bonding of contamination to waste glass canisters. Surface pretreatments which produce smoother canister surfaces actually cause radioactive contamination to be more tightly bonded to the metal surface than on an untreated surface. Based on the results of these tests it is recommended that the canister surface finish be specified as having a bright cold rolled mill finish equivalent to ASTM No. 2B. 7 references, 3 figures, 3 tables

  11. Improvement of a device for monitoring the contamination of surfaces

    International Nuclear Information System (INIS)

    Barbier, Albert.

    1981-01-01

    The purpose of this invention is to make it possible to monitor the contamination of surfaces by a light weight portable device and enabling the alpha, beta and gamma radiation contamination to be detected. The detection probe which is connected by a single lead to the box is adapted, in each particular case, to the radiation mode emitted by the contaminated surfaces and the box is provided with a special leak-proof socket for connecting the probe and includes means for assessing the counting rate of the radiation given off, depending on the mode of the radiations emitted by the contaminated surfaces and the intensity of the count rate [fr

  12. Measurement of radioactivity in contaminated crops

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Y; Hasegawa, M; Kihara, T

    1956-01-01

    A method called the Direct Method was developed to correct for natural /sup 40/K radiation in plant samples. The K content of the ashed sample is determined by flamephotometry. The radioactivity in a 100 mg sample is measured and the natural radioactivity from /sup 40/K determined by calculation subtracted. Tea samples tested gave evidence of contamination by radioactive fallout.

  13. Experimental study on source efficiencies for estimating surface contamination level

    International Nuclear Information System (INIS)

    Ichiji, Takeshi; Ogino, Haruyuki

    2008-01-01

    Source efficiency was measured experimentally for various materials, such as metals, nonmetals, flooring materials, sheet materials and other materials, contaminated by alpha and beta emitter radioactive nuclides. Five nuclides, 147 Pm, 60 Co, 137 Cs, 204 Tl and 90 Sr- 90 Y, were used as the beta emitters, and one nuclide 241 Am was used as the alpha emitter. The test samples were prepared by placing drops of the radioactive standardized solutions uniformly on the various materials using an automatic quantitative dispenser system from Musashi Engineering, Inc. After placing drops of the radioactive standardized solutions, the test materials were allowed to dry for more than 12 hours in a draft chamber with a hood. The radioactivity of each test material was about 30 Bq. Beta rays or alpha rays from the test materials were measured with a 2-pi gas flow proportional counter from Aloka Co., Ltd. The source efficiencies of the metals, nonmetals and sheet materials were higher than 0.5 in the case of contamination by the 137 Cs, 204 Tl and 90 Sr- 90 Y radioactive standardized solutions, higher than 0.4 in the case of contamination by the 60 Co radioactive standardized solution, and higher than 0.25 in the case of contamination by the alpha emitter the 241 Am radioactive standardized solution. These values were higher than those given in Japanese Industrial Standards (JIS) documents. In contrast, the source efficiencies of some permeable materials were lower than those given in JIS documents, because source efficiency varies depending on whether the materials or radioactive sources are wet or dry. This study provides basic data on source efficiency, which is useful for estimating the surface contamination level of materials. (author)

  14. Measurement of complex surfaces

    International Nuclear Information System (INIS)

    Brown, G.M.

    1993-05-01

    Several of the components used in coil fabrication involve complex surfaces and dimensions that are not well suited to measurements using conventional dimensional measuring equipment. Some relatively simple techniques that are in use in the SSCL Magnet Systems Division (MSD) for incoming inspection will be described, with discussion of their suitability for specific applications. Components that are submitted for MSD Quality Assurance (QA) dimensional inspection may be divided into two distinct categories; the first category involves components for which there is an approved drawing and for which all nominal dimensions are known; the second category involves parts for which 'reverse engineering' is required, the part is available but there are no available drawings or dimensions. This second category typically occurs during development of coil end parts and coil turn filler parts where it is necessary to manually shape the part and then measure it to develop the information required to prepare a drawing for the part

  15. Ion implanters contamination on wafer surface analyzed by ToF-SIMS and SPV analytical techniques

    International Nuclear Information System (INIS)

    Ricciari, R.; Bertini, M.; Ferlito, E.P.; Pizzo, G.; Anastasi, G.; Mello, D.; Franco, G.

    2007-01-01

    In ULSI processes, metallic contamination controls are very important issues. For the ion implantation process it is known that several sources of contaminations still need to be controlled: metals from sputtering of the apertures or wafer holders, Na + contaminations from filament impurities and messy maintenance procedure. ToF-SIMS is one of the most promising candidates to perform in-line surface analysis due to its high sensitivity. It is very common to use surface photo-voltage (SPV) techniques to control ion implanter equipments but this kind of analysis is an indirect measure for metallic contamination. The aim of this work is to study the possibility to use ToF-SIMS instead of SPV for in line equipment contamination monitoring. For this reason a comparison between SPV and ToF-SIMS data occurred. Good correlation between the data is shown; moreover ToF-SIMS spectra give detailed information about the other contaminations present on the wafer surface

  16. A criterion of contamination of the glass surface of photovoltaic batteries

    International Nuclear Information System (INIS)

    Tursunov, M.N.; Dyskin, V.G.; Yuldashev, I.A. et al.; Park Jeong Hwoan

    2015-01-01

    The relative change in the coefficient of efficiency is chosen as a criterion for contamination of the glass surface of a photovoltaic battery. Using the formula obtained, the results of measurements of the transmission coefficient of a contaminated glass plate after its exposure to open air in the center of Tashkent for 80 and 110 days are processed. It is shown that the contamination of the glass plate reduces the coefficient of efficiency of the PVB by 50.0%. (authors)

  17. Surface contamination to UV-curable acrylates in the furniture and parquet industry.

    Science.gov (United States)

    Surakka, J; Lindh, T; Rosén, G; Fischer, T

    2001-03-01

    Surface contamination to ultraviolet radiation curable coatings (UV coatings), used increasingly in the parquet and furniture industry, is a matter of concern as a source for skin contamination. UV coatings contain chemically and biologically reactive acrylates, well known as skin contact irritants and sensitizers. Surface contamination may spread secondarily to equipment and other unexpected areas even outside the workplace. Yet, studies concerning this type of contamination are lacking due to lack of suitable sampling methods. Surface contamination of the work environment with risk for skin exposure to UV coating was measured employing a quantitative adhesive tape sampling method developed for this purpose. A pilot study was first performed at three workplaces to evaluate the contamination. In the main study, we wanted to locate and identify in detail the surface contamination of areas where problems exist, and to determine the extent of the problem. Measurements were performed at seven workplaces on two separate workdays (round 1 and 2) within a six-month period. Samples were collected from the workplaces based on the video monitoring of skin contact frequency with the surfaces and categorized into three groups to analyze risk. The pilot study indicated that surface contamination to TPGDA containing UV coatings was common, found in 76 percent of the surfaces, and varied with a maximum of 909 microg TPGDA 10 cm(-2) sampling area. In the main study TPGDA was found in 153 out of 196 collected samples (78.1%); for round one 78.1 percent (82 out of 105 samples) and for round two 78.0 percent (71 out of 91 samples). The average TPGDA mass on positive surface samples was on the first round 2,247 +/- 7,462 microg, and on the second round 2,960 +/- 4,590 microg. We conclude that surface contamination to uncured UV coatings at UV-curing lines is common and this involves a risk for harmful, unintentional skin exposure to acrylates.

  18. Total effective dose equivalent associated with fixed uranium surface contamination

    International Nuclear Information System (INIS)

    Bogard, J.S.; Hamm, R.N.; Ashley, J.C.; Turner, J.E.; England, C.A.; Swenson, D.E.; Brown, K.S.

    1997-04-01

    This report provides the technical basis for establishing a uranium fixed-contamination action level, a fixed uranium surface contamination level exceeding the total radioactivity values of Appendix D of Title 10, Code of Federal Regulations, part 835 (10CFR835), but below which the monitoring, posting, and control requirements for Radiological Areas are not required for the area of the contamination. An area of fixed uranium contamination between 1,000 dpm/100 cm 2 and that level corresponding to an annual total effective dose equivalent (TEDE) of 100 mrem requires only routine monitoring, posting to alert personnel of the contamination, and administrative control. The more extensive requirements for monitoring, posting, and control designated by 10CFR835 for Radiological Areas do not have to be applied for these intermediate fixed-contamination levels

  19. Modeling of laser damage initiated by surface contamination

    International Nuclear Information System (INIS)

    Feit, M.D.; Rubenchik, A.M.; Faux, D.R.; Riddle, R.A.; Shapiro, A.; Eder, D.C.; Penetrante, B.M.; Milam, D.; Genin, F.Y.; Kozlowski, M.R.

    1996-11-01

    The authors are engaged in a comprehensive effort to understand and model the initiation and growth of laser damage initiated by surface contaminants. This includes, for example, the initial absorption by the contaminant, heating and plasma generation, pressure and thermal loading of the transparent substrate, and subsequent shockwave propagation, 'splashing' of molten material and possible spallation, optical propagation and scattering, and treatment of material fracture. The integration use of large radiation hydrodynamics codes, optical propagation codes and material strength codes enables a comprehensive view of the damage process The following picture of surface contaminant initiated laser damage is emerging from our simulations

  20. Optimization in the nuclear fuel cycle II: Surface contamination

    International Nuclear Information System (INIS)

    Pereira, W.S.; Silva, A.X.; Lopes, J.M.; Carmo, A.S.; Fernandes, T.S.; Mello, C.R.; Kelecom, A.

    2017-01-01

    Optimization is one of the bases of radioprotection and aims to move doses away from the dose limit that is the borderline of acceptable radiological risk. This work aims to use the monitoring of surface contamination as a tool of the optimization process. 53 surface contamination points were analyzed at a nuclear fuel cycle facility. Three sampling points were identified with monthly mean values of contamination higher than 1 Bq ∙ cm -2 , points 28, 42 and 47. These points were indicated for the beginning of the optimization process

  1. Quality assurance measures and calibration of contamination meters at FAG-Kugelfischer

    International Nuclear Information System (INIS)

    Schloesser, H.

    1992-01-01

    The quality assurance measures taken in connection with the production of contamination meters according to the DIN 44801 standard are explained with regard to the individual components of such instruments, which include mechanical, electronic and detector elements. After the relevant calibration procedures have been described, the author proceeds to draw the reader's attention to potentials for error in measurements of surface contamination. (orig.) [de

  2. Estimating dermal transfer from PCB-contaminated porous surfaces.

    Science.gov (United States)

    Slayton, T M; Valberg, P A; Wait, A D

    1998-06-01

    Health risks posed by dermal contact with PCB-contaminated porous surfaces have not been directly demonstrated and are difficult to estimate indirectly. Surface contamination by organic compounds is commonly assessed by collecting wipe samples with hexane as the solvent. However, for porous surfaces, hexane wipe characterization is of limited direct use when estimating potential human exposure. Particularly for porous surfaces, the relationship between the amount of organic material collected by hexane and the amount actually picked up by, for example, a person's hand touch is unknown. To better mimic PCB pickup by casual hand contact with contaminated concrete surfaces, we used alternate solvents and wipe application methods that more closely mimic casual dermal contact. Our sampling results were compared to PCB pickup using hexane-wetted wipes and the standard rubbing protocol. Dry and oil-wetted samples, applied without rubbing, picked up less than 1% of the PCBs picked up by the standard hexane procedure; with rubbing, they picked up about 2%. Without rubbing, saline-wetted wipes picked up 2.5%; with rubbing, they picked up about 12%. While the nature of dermal contact with a contaminated surface cannot be perfectly reproduced with a wipe sample, our results with alternate wiping solvents and rubbing methods more closely mimic hand contact than the standard hexane wipe protocol. The relative pickup estimates presented in this paper can be used in conjunction with site-specific PCB hexane wipe results to estimate dermal pickup rates at sites with PCB-contaminated concrete.

  3. Development of an automatic smear sampler and evaluation of surface contamination

    International Nuclear Information System (INIS)

    Seo, B. K.; Lee, B. J.; Lee, K. W.; Park, J. H.

    2004-01-01

    The surface contamination level of a radiation-controlled area is measured periodically according to atomic energy law and connection regulations. The measurement of surface contamination by an indirect method is subject to various kinds of error depending on the sampling person and consumes much time and effort in the sampling of large nuclear facilities. In this research, an automatic smear sampler is developed to solve these problems. The developed equipment is composed of a rotating sampling part, a sample transferring part, a power supply part a control part, and vacuum part. It improved the efficiency of estimation of the surface contamination level achieved periodically in a radiation-controlled area. Using an automatic smear sampler developed in this research, it is confirmed that radioactive contaminated materials are uniformly transferred to smear paper more than any sampling method by an operator. (authors)

  4. Process for cleaning radioactively contaminated metal surfaces

    International Nuclear Information System (INIS)

    Mihram, R.G.; Snyder, G.A.

    1975-01-01

    A process is described for removing radioactive scale from a ferrous metal surface, including the steps of initially preconditioning the surface by contacting it with an oxidizing solution (such as an aqueous solution of an alkali metal permanganate or hydrogen peroxide), then, after removal or decomposition of the oxidizing solution, the metallic surface is contacted with a cleaning solution which is a mixture of a mineral acid and a complexing agent (such as sulfuric acid and oxalic acid), and which preferably contains a corrosion inhibitor. A final step in the process is the treatment of the spent cleaning solution containing radioactive waste materials in solution by adding a reagent selected from the group consisting of calcium hydroxide or potassium permanganate and an alkali metal hydroxide to thereby form easily recovered metallic compounds containing substantially all of the dissolved metals and radioactivity. (auth)

  5. Methods for the calculation of derived working limits for surface contamination by low-toxicity radionuclides

    International Nuclear Information System (INIS)

    Gibson, J.A.B.; Wrixon, A.D.

    1979-01-01

    Surface contamination is often measured as an indication of the general spread of radioactive contamination in a particular place. Derived working limits, (DWLs) for surface contamination provide figures against which to assess the significance of measurements. Derived working limits for surface contamination were first established for use in the nuclear energy industry. They were designed to cope with a wide range of unspecified radionuclides and were therefore based on the assumption that the contamination was due to the presence of the most hazardous radionuclides, e.g. 90 Sr, 210 Pb, 226 Ra and 239 Pu. While this assumption may still be appropriate when the radionuclide mixture is unknown, there are now many specialized uses of particular low-toxicity radionuclides in universities, hospitals and general industry. If it is known that only a particular radionuclide is present, the general DWL can be replaced by a more specific value. The methods for calculating DWLs for some of the more commonly employed low-toxicity radionuclides are described. The exposure pathways considered are (a) external radiation of the skin and inhalation of airborne material from contaminated surfaces in active areas; (b) external irradiation of the skin and ingestion from contaminated skin. Some consideration is given to the effect of the revised dose equivalent limits in the most recent recommendations of ICRP. (author)

  6. Cleaning, disinfection and sterilization of surface prion contamination.

    Science.gov (United States)

    McDonnell, G; Dehen, C; Perrin, A; Thomas, V; Igel-Egalon, A; Burke, P A; Deslys, J P; Comoy, E

    2013-12-01

    Prion contamination is a risk during device reprocessing, being difficult to remove and inactivate. Little is known of the combined effects of cleaning, disinfection and sterilization during a typical reprocessing cycle in clinical practice. To investigate the combination of cleaning, disinfection and/or sterilization on reducing the risk of surface prion contamination. In vivo test methods were used to study the impact of cleaning alone and cleaning combined with thermal disinfection and high- or low-temperature sterilization processes. A standardized test method, based on contamination of stainless steel wires with high titres of scrapie-infected brain homogenates, was used to determine infectivity reduction. Traditional chemical methods of surface decontamination against prions were confirmed to be effective, but extended steam sterilization was more variable. Steam sterilization alone reduced the risk of prion contamination under normal or extended exposure conditions, but did show significant variation. Thermal disinfection had no impact in these studies. Cleaning with certain defined formulations in combination with steam sterilization can be an effective prion decontamination process, in particular with alkaline formulations. Low-temperature, gaseous hydrogen peroxide sterilization was also confirmed to reduce infectivity in the presence and absence of cleaning. Prion decontamination is affected by the full reprocessing cycle used on contaminated surfaces. The correct use of defined cleaning, disinfection and sterilization methods as tested in this report in the scrapie infectivity assay can provide a standard precaution against prion contamination. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  7. Analysis of surface contaminants on beryllium windows

    International Nuclear Information System (INIS)

    Gmur, N.F.

    1986-12-01

    It is known that various crystalline and liquid compounds form on the downstream surfaces of beryllium windows exposed to air. It is also known that the integrity of such windows may be compromised resulting in leaks through the window. The purpose of this report is to document the occurrences described as they pertain to the NSLS and to analyze, where possible, the various substances formed

  8. Measurement of surface roughness

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo

    This document is used in connection with two 3 hours laboratory exercises that are part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The laboratories include a demonstration of the function of roughness measuring instruments plus a series of exercises illustrating roughness measurement...

  9. Development of an automatic smear sampler and a polymer film for surface radioactive contamination assay

    International Nuclear Information System (INIS)

    Seo, B.-K.; Lee, K.-W.; Woo, Z.-H.; Jeong, K.-S.; Oh, W.-Z.; Han, M.-J.

    2004-01-01

    Measurement of the surface contamination by an indirect method is subject to the various kinds of error according to the sampling person and needs much time and effort in the sampling and assay. In this research, an automatic smear sampler is developed. It improved efficiency for assay work of surface contamination level achieved periodically in a radiation controlled area. Using an automatic smear sampler developed, it is confirmed that radioactive contaminated materials are uniformly transferred to smear paper more than any sampling method by an operator. Also, Solid scintillation proximity membranes were prepared for measuring the amount of radioactive contamination in laboratories contaminated by the low energy beta-ray emitter, such as 3 H and 14 C. Polysulfone scintillation proximity membranes were prepared by impregnating Cerium Activated Yttrium Silicate (CAYS), an inorganic fluor, in a membrane structure. The inorganic fluor-impregnated membranes were applied to detect the radioactive surface contamination. The preparation of membranes was divided into two processes. A supporting polymer film was made of casting solutions consisting of polysulfone and solvent, their cast film being solidified by vacuum evaporation. CAYS-dispersed polymer solutions were cast over the first, solidified polymer films and coagulated either by evaporating solvent in the solution with non-solvent in a coagulation bath. The prepared membranes had two distinguished, but tightly attached, double layers : one is the supporting layer of dense polymer film and the other results revealed that the prepared membranes were efficient to monitor radioactive contamination with reliable counting ability. For enhancement of pick-up and measurement efficiency, the membrane was prepared with the condition of different membrane solidification. The scintillation produced by interaction with radiation and CAYS was measured with photomultiplier tube. The test results showed that the prepared

  10. Techniques for removing contaminants from optical surfaces

    International Nuclear Information System (INIS)

    Stowers, I.F.; Patton, H.G.

    1978-01-01

    Particle removal procedures such as plasma cleaning, ultrasonic agitation of solvents, detergents, solvent wiping, mild abrasives, vapor degreasing, high pressure solvent spraying and others have been evaluated and the results are reported here. Wiping with a lens tissue wetted with an organic solvent and high pressure fluid spraying are the only methods by which particles as small as 5 μm can be effectively removed. All of the other methods tested were found to be at least two orders of magnitude less effective at removing small insoluble particles. An additional and as yet unresolved problem is the development of a reliable method for evaluating particulate surface cleanliness. Without such a reproducible monitoring technique, the large diversity of cleaning methods currently available cannot be quantitatively evaluated

  11. Online Oxide Contamination Measurement and Purification Demonstration

    Science.gov (United States)

    Bradley, D. E.; Godfroy, T. J.; Webster, K. L.; Garber, A. E.; Polzin, K. A.; Childers, D. J.

    2011-01-01

    Liquid metal sodium-potassium (NaK) has advantageous thermodynamic properties indicating its use as a fission reactor coolant for a surface (lunar, martian) power system. A major area of concern for fission reactor cooling systems is system corrosion due to oxygen contaminants at the high operating temperatures experienced. A small-scale, approximately 4-L capacity, simulated fission reactor cooling system employing NaK as a coolant was fabricated and tested with the goal of demonstrating a noninvasive oxygen detection and purification system. In order to generate prototypical conditions in the simulated cooling system, several system components were designed, fabricated, and tested. These major components were a fully-sealed, magnetically-coupled mechanical NaK pump, a graphite element heated reservoir, a plugging indicator system, and a cold trap. All system components were successfully demonstrated at a maximum system flow rate of approximately 150 cc/s at temperatures up to 550 C. Coolant purification was accomplished using a cold trap before and after plugging operations which showed a relative reduction in oxygen content.

  12. Combined Contamination and Space Environmental Effects on Solar Cells and Thermal Control Surfaces

    Science.gov (United States)

    Dever, Joyce A.; Bruckner, Eric J.; Scheiman, David A.; Stidham, Curtis R.

    1994-01-01

    For spacecraft in low Earth orbit (LEO), contamination can occur from thruster fuel, sputter contamination products and from products of silicone degradation. This paper describes laboratory testing in which solar cell materials and thermal control surfaces were exposed to simulated spacecraft environmental effects including contamination, atomic oxygen, ultraviolet radiation and thermal cycling. The objective of these experiments was to determine how the interaction of the natural LEO environmental effects with contaminated spacecraft surfaces impacts the performance of these materials. Optical properties of samples were measured and solar cell performance data was obtained. In general, exposure to contamination by thruster fuel resulted in degradation of solar absorptance for fused silica and various thermal control surfaces and degradation of solar cell performance. Fused silica samples which were subsequently exposed to an atomic oxygen/vacuum ultraviolet radiation environment showed reversal of this degradation. These results imply that solar cells and thermal control surfaces which are susceptible to thruster fuel contamination and which also receive atomic oxygen exposure may not undergo significant performance degradation. Materials which were exposed to only vacuum ultraviolet radiation subsequent to contamination showed slight additional degradation in solar absorptance.

  13. Worker exposures from recycling surface contaminated radioactive scrap metal

    International Nuclear Information System (INIS)

    Kluk, A.; Phillips, J.W.; Culp, J.

    1996-01-01

    Current DOE policy permits release from DOE control of real property with residual levels of surficial radioactive contamination if the contamination is below approved guidelines. If the material contains contamination that is evenly distributed throughout its volume (referred to as volumetric contamination), then Departmental approval for release must be obtained in advance. Several DOE sites presently recycle surface contaminated metal, although the quantities are small relative to the quantities of metal processed by typical mini-mills, hence the potential radiation exposures to mill workers from processing DOE metals and the public from the processed metal are at present also a very small fraction of their potential value. The exposures calculated in this analysis are based on 100% of the scrap metal being processed at the maximum contamination levels and are therefore assumed to be maximum values and not likely to occur in actual practice. This paper examines the relationship between the surface contamination limits established under DOE Order 5400.5, open-quotes Radiation Protection of the Public and the Environment,close quotes and radiation exposures to workers involved in the scrap metal recycling process. The analysis is limited to surficial contamination at or below the guideline levels established in DOE Order 5400.5 at the time of release. Workers involved in the melting and subsequent fabrication of products are not considered radiation workers (no requirements for monitoring) and must be considered members of the public. The majority of the exposures calculated in this analysis range from tenths of a millirem per year (mrem/yr) to less than 5 mrem/yr. The incremental risk of cancer associated with these exposures ranges from 10 -8 cancers per year to 10 -6 cancers per year

  14. Modelling of contamination of surface atmosphere for deflation of Cesium-137 on contaminated territories

    International Nuclear Information System (INIS)

    Bogdanov, A.P.; Zhmura, G.M.

    1994-01-01

    Presence of Cesium 137 in near land air is caused at the contaminated territories by 'local' dusting and transport of the dust from the zone of strong contamination. For large distance is it caused by resuspension of radioactive dust from the surface in the given region. In accordance with the models of dusting round square sources based on Gauss statistical model of dissemination of admixtures in the atmosphere, the contaminated areas of european part of the former of USSR with the density of contamination over 1 Ci/km 2 with Cesium 137 were represented by 30 round square sources covering the main spots of contamination. The results of calculation of contamination of the atmosphere for several cities of Belarus, Russia and Ukraine, where there are the permanent points of observation for the content of radionuclides in the air, have shown that the proposed model of dusting sources describes the contamination of near land air with Cesium 137 reasonably well. 7 refs., 3 tabs

  15. Surface Contamination Monitor and Survey Information Management System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    Shonka Research Associates, Inc.`s (SRA) Surface Contamination Monitor and Survey Information management System (SCM/SIMS) is designed to perform alpha and beta radiation surveys of floors and surfaces and document the measured data. The SRA-SCM/SIMS technology can be applied to routine operational surveys, characterization surveys, and free release and site closure surveys. Any large nuclear site can make use of this technology. This report describes a demonstration of the SRA-SCM/SIMS technology. This demonstration is part of the chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), Office of Science and Technology (ST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East`s (ANL) CP-5 Research Reactor Facility. The purpose of the LSDP is to demonstrate that by using innovative and improved deactivation and decommissioning (D and D) technologies from various sources, significant benefits can be achieved when compared to baseline D and D technologies.

  16. Development of apparatus for surveying uranium surface contamination quantity

    International Nuclear Information System (INIS)

    Wang Qingheng; Han Jingquan

    1994-11-01

    An apparatus for measuring uranium contamination of the surface of reactor plate component is described. The searching unit of the apparatus is a large surface multi-wire proportional counter. The cathode of the counter is made of stainless steel with low radioactive background, the window is made of film which is plated with aluminum about 6 μm; and the anode is mad by gild tungsten wire of 0.025 mm diameter. The sensitive area of the counter is 1113 mm x 100 mm. It has been shown that the intrinsic radioactive background of the apparatus is 0.002 cpm/cm 2 (2 count/min). The detecting efficiency is 67% for enriched uranium source (2π solid angle). The stability is 0.84% within 24 hour (including detector, high voltage power supply, amplifier, discriminator, computer, type and display system). The lower detection limit of the apparatus is 4.6 x 10 -10 g/cm 2 (for 20% 235 U, 0.13% 234 U, 79.64% 238 U). The apparatus can present timing by a computer controlling, and it also has the following functions: displaying, automatic alarming, classifying and typing the results. (2 tabs., 7 figs.)

  17. Surface Contamination Monitor and Survey Information Management System

    International Nuclear Information System (INIS)

    1998-02-01

    Shonka Research Associates, Inc.'s (SRA) Surface Contamination Monitor and Survey Information management System (SCM/SIMS) is designed to perform alpha and beta radiation surveys of floors and surfaces and document the measured data. The SRA-SCM/SIMS technology can be applied to routine operational surveys, characterization surveys, and free release and site closure surveys. Any large nuclear site can make use of this technology. This report describes a demonstration of the SRA-SCM/SIMS technology. This demonstration is part of the chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), Office of Science and Technology (ST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East's (ANL) CP-5 Research Reactor Facility. The purpose of the LSDP is to demonstrate that by using innovative and improved deactivation and decommissioning (D and D) technologies from various sources, significant benefits can be achieved when compared to baseline D and D technologies

  18. Assessment of arsenic surface contamination in a museum anthropology department.

    Science.gov (United States)

    Gribovich, Andrey; Lacey, Steven; Franke, John; Hinkamp, David

    2013-02-01

    To assess potential arsenic (As) contamination of work surfaces to improve upon the control strategy at an anthropology department in a large natural history museum. Work practices were observed and control strategy reviewed to inform an occupational hygiene assessment strategy utilizing surface wipe sampling. A total of 35 sampling targets were identified, focusing on surfaces that receive high touch traffic, including workstations, artifact transport carts, and elevator buttons. Arsenic sampling and analysis were performed using reference method Occupational Safety and Health Administration ID-125G. Four of the sampling areas returned detectable levels of As, ranging from 0.052 to 0.350 μg/100 cm. Workplace observations and wipe sampling data enabled the development of recommendations to help to further reduce potential occupational exposure to As. Continuous reduction of surface contamination is prudent for known human carcinogens.

  19. Field Measurements of PCB emissions from Building Surfaces Using a New Portable Emission Test Cell

    DEFF Research Database (Denmark)

    Lyng, Nadja; Haven, Rune; Gunnarsen, Lars Bo

    2016-01-01

    The purpose of the study was to measure PCB-emission rates from indoor surfaces on-site in contaminated buildings using a newly developed portable emission test cell. Emission rates were measured from six different surfaces; three untreated surfaces and three remediated surfaces in a contaminated...

  20. Development of a calibration system for surface contamination monitors

    International Nuclear Information System (INIS)

    Marechal, M.H.H.; Barbosa, M.P.

    1992-01-01

    A calibration system for surface contamination monitors is developed, aiming supply the existence demand of these instruments. A experimental arrangement and a methodology are described. The advantages of use this system for calibration routine optimization are also discussed. (C.G.C.)

  1. Deuteriding of thin titanium films: the effect of carbon monoxide surface contamination

    International Nuclear Information System (INIS)

    Malinowski, M.W.

    1976-02-01

    The effect of adsorbed CO on the deuteriding of thin titanium films at room temperature was measured at D 2 pressures between 10 to 25 mtorr on films contaminated with CO exposures ranging between approximately 10 -8 torr-seconds (''clean'') to 10 -4 torr-seconds. In all measurements, for deuterium/titanium atom ratios greater than .2, the deuteriding appeared to be initally limited by the sticking of D 2 on the clean or contaminated titanium deuteride surface; the effective sticking coefficient on a clean titanium deuteride surface was approximately 3 x 10 -3 , while on a surface contaminated with 10 -4 torr-seconds of CO, the coefficient was reduced to approximately, 2 x 10 -4 . The pumping speeds of Ti films were dramatically different when the films were evaporated over TiD 2 . These changes were attributed to the presence of deuterium which diffused from the substrate film into the overlayer film

  2. Influence of the target surface contamination on UHV screening energies

    Energy Technology Data Exchange (ETDEWEB)

    Targosz-Sleczka, N; Czerski, K; Kilic, A I [Institute of Physics, University of Szczecin, Szczecin (Poland); Huke, A; Martin, L; Heide, P [Institut fuer Atomare Physik und Optik, Technische Universitaet Berlin, Berlin (Germany); Blauth, D; Winter, H, E-mail: natalia.targosz@wmf.univ.szczecin.p [Institut fuer Physik, Humboldt-Universitaet zu Berlin, Berlin (Germany)

    2010-01-01

    The d + d fusion reactions have been investigated in the Zirconium environment under ultra high vacuum (UHV) conditions for projectile energies below 30 keV. The experimentally determined screening energy value of 497 {+-} 7 eV is larger than the previous results by a factor of almost two. Despite the UHV conditions a small deviation between experimental data and the theoretical curve arising from the target surface contamination could be still observed at the lowest projectile energies. Calculations made under the assumption of formation of a Zirconium oxide contamination, show that every atomic monolayer reduces the estimated screening energy significantly.

  3. Influence of the target surface contamination on UHV screening energies

    International Nuclear Information System (INIS)

    Targosz-Sleczka, N; Czerski, K; Kilic, A I; Huke, A; Martin, L; Heide, P; Blauth, D; Winter, H

    2010-01-01

    The d + d fusion reactions have been investigated in the Zirconium environment under ultra high vacuum (UHV) conditions for projectile energies below 30 keV. The experimentally determined screening energy value of 497 ± 7 eV is larger than the previous results by a factor of almost two. Despite the UHV conditions a small deviation between experimental data and the theoretical curve arising from the target surface contamination could be still observed at the lowest projectile energies. Calculations made under the assumption of formation of a Zirconium oxide contamination, show that every atomic monolayer reduces the estimated screening energy significantly.

  4. Laser Decontamination of Surfaces Contaminated with Cs+ Ion

    International Nuclear Information System (INIS)

    Baigalmaaa, B.; Won, H. J.; Moon, J. K.; Jung, C. H.; Lee, K. W.; Hyun, J. H.

    2008-01-01

    Laser decontamination technology has been proven to be an efficient method for a surface modification of metals and concretes contaminated with radioactive isotopes. Furthermore, the generation of a secondary waste is negligible. The radioactivity of hot cells in the DFDF (Dupic Fuel Development Facility) is presumed to be very high and the predominant radionuclide is Cs-137. A series of laser decontamination studies by a fabricated Q-switched Nd:YAG laser system were performed on stainless steel specimens artificially contaminated with Cs+ ion. Decontamination characteristics of the stainless steel were analyzed by SEM and EPMA

  5. Verification of surface contamination density standard using clearance automatic laser inspection system for objects from a nuclear power plant

    International Nuclear Information System (INIS)

    Sasaki, Michiya; Ogino, Haruyuki; Ichiji, Takeshi; Hattori, Takatoshi

    2008-01-01

    In the clearance level inspection in Japan, it is necessary to indicate that the activity level of the target object must be less than not only the clearance levels, but also the surface contamination density standards. The classification measurements for these two standards have been performed separately, and the GM survey meters based on beta-ray measurement have mainly been used for surface contamination density measurement so far. Recently the Clearance Automatic Laser Inspection System, named CLALIS, has been developed to estimate the low-level activity concentration. This system consists of 3-dimensional laser scanner for shape measurement and eight large NE102A plastic scintillation detectors for gamma-ray measurement, and it has been clarified that the CLALIS has adequate detection ability for clearance measurement of both metal scraps and concrete debris. In this study, we compared the surface contamination densities for a number of actual contaminated and non-contaminated objects generated inside from the radiation controlled area at the Kashiwazaki-Kariwa nuclear power station by using the CLALIS and the GM survey meter. As a result, since CLALIS could detect the surface contamination as well as the GM survey meter for all measurement targets, it was revealed that CLALIS can rationally achieve clearance level inspection in a single radiation measurement. The practicality of CLALIS in view of the detection limit and processing time was discussed by comparison with the usual radiation monitors for surface contamination measurement. (author)

  6. Experiment on Physical Desalinisation of Uranium-contaminated Gravel Surface

    International Nuclear Information System (INIS)

    Park, Uk-Ryang; Kim, Gye-Nam; Kim, Seung-Soo; Han, Gyu-Seong; Moon, Jai-Kwon

    2014-01-01

    As a result, the method to wash uranium-contaminated gravels could not get satisfactory desalinization rate. During the long oxidization process it was judged that uranium penetrated inside the gravels, so we tried to increase the desalinization rate by fragmentizing them into pieces and then washing them. The desalinization rate after fragmentizing the gravels into pieces and washing them brought a satisfactory result.. However, we could obtain desired concentration for gravels with high uranium concentration by fragmentizing them and breaking them further into even smaller pieces. Likewise, desalinization using soil washing process is complicated and has to go through multiple washing steps, resulting in too much of waste fluid generated accordingly. The increase of waste fluid generated leads to the increase in by-products of the final disposal process later on, bringing a not good economic result. Furthermore, taking into account that the desalinization rate is 65% during soil washing process, it is expected that gravel washing will show a similar desalinization result; it is considered uneasy to have a perfect desalinization only by soil washing. The grinding method is actually used in the primary desalinization process in order to desalinize radioactivity-contaminated concrete. This method does desalinization by grinding the radioactivity-contaminated area of the concrete surface with desalinization equipment, which enables a near-to-perfect desalinization for relatively thinly contaminated surface. Likewise, this research verified the degree of desalinization by applying the grinding method and comparing it to the fragmentizing-washing method, and attempted to find a method to desalinize uranium-contaminated gravels more effectively. In order to desalinize uranium-contaminated gravels more effectively and compare to the existing washing-desalinization method, we conducted a desalinization experiment with grinding method that grinds gravel surface. As a

  7. Armor Plate Surface Roughness Measurements

    National Research Council Canada - National Science Library

    Stanton, Brian; Coburn, William; Pizzillo, Thomas J

    2005-01-01

    ...., surface texture and coatings) that could become important at high frequency. We measure waviness and roughness of various plates to know the parameter range for smooth aluminum and rolled homogenous armor (RHA...

  8. Application Of The SPV-based Surface Lifetime Technique To In-Line Monitoring Of Surface Cu Contamination

    Science.gov (United States)

    D'Amico, John; Savtchouk, Alexandre; Wilson, Matthew; Kim, Chul Hong; Yoo, Hyung Won; Lee, Chang Hwan; Kim, Tae Kyoung; Son, Sang Hoon

    2009-09-01

    Implementation of Cu interconnects into Silicon Integrated Circuits (IC's) has been instrumental in the continuing improvement of IC device performance. Copper as a well known Gate Oxide Integrity (GOI) killer [1, 2] requires extensive protocols to minimize the possibility of cross contamination. Despite such protocols the risk for cross contamination exists, and consequently there is the need for in-line Cu cross-contamination detection metrology. Preferably the metrology will be non-destructive, fast, and capable of mapping on product wafers. Up to now the most common approaches for monitoring Cu contamination in IC fabrication lines either measure Cu in the bulk Si, which is not applicable to Cu cross-contamination monitoring because Back-End-of-the-Line thermal budgets restrict the ability to diffuse the surface Cu into the bulk Si; or the techniques are not optimal for in-line monitoring due to their destructive, time-consuming, or costly nature. In this work we demonstrate for the first time the application of the ac-Surface Photo Voltage (ac-SPV) surface lifetime approach [3] to in-line, full wafer coverage mapping of low level (metrology system. Furthermore, because the metrology is non-contact (utilizing edge-grip handling) and non-destructive, it is directly applicable to measurement of production wafers. In-line fab data acquired using this metrology is presented and compared to data from Inductively Coupled Plasma Mass Spectroscopy (ICP-MS).

  9. Residual viral and bacterial contamination of surfaces after cleaning and disinfection

    NARCIS (Netherlands)

    Tuladhar, E.; Hazeleger, W.C.; Koopmans, M.; Zwietering, M.H.; Beumer, R.R.; Duizer, E.

    2012-01-01

    Environmental surfaces contaminated with pathogens can be sources of indirect transmission, and cleaning and disinfection are common interventions focused on reducing contamination levels. We determined the efficacy of cleaning and disinfection procedures for reducing contamination by noroviruses,

  10. Reactor surface contamination stabilization. Innovative technology summary report

    International Nuclear Information System (INIS)

    1998-11-01

    Contaminated surfaces, such as the face of a nuclear reactor, need to be stabilized (fixed) to avoid airborne contamination during decontamination and decommissioning activities, and to prepare for interim safe storage. The traditional (baseline) method of fixing the contamination has been to spray a coating on the surfaces, but ensuring complete coverage over complex shapes, such as nozzles and hoses, is difficult. The Hanford Site C Reactor Technology Demonstration Group demonstrated innovative technologies to assess stabilization properties of various coatings and to achieve complete coverage of complex surfaces on the reactor face. This demonstration was conducted in two phases: the first phase consisted of a series of laboratory assessments of various stabilization coatings on metal coupons. For the second phase, coatings that passed the laboratory tests were applied to the front face of the C Reactor and evaluated. The baseline coating (Rust-Oleum No. 769) and one of the innovative technologies did not completely cover nozzle assemblies on the reactor face, the most critical of the second-phase evaluation criteria. However, one of the innovative coating systems, consisting of a base layer of foam covered by an outer layer of a polymeric film, was successful. The baseline technology would cost approximately 33% as much as the innovative technology cost of $64,000 to stabilize an entire reactor face (196 m 2 or 2116 ft 2 ) with 2,004 nozzle assemblies, but the baseline system failed to provide complete surface coverage

  11. Surface contamination of hazardous drug pharmacy storage bins and pharmacy distributor shipping containers.

    Science.gov (United States)

    Redic, Kimberly A; Fang, Kayleen; Christen, Catherine; Chaffee, Bruce W

    2018-03-01

    Purpose This study was conducted to determine whether there is contamination on exterior drug packaging using shipping totes from the distributor and carousel storage bins as surrogate markers of external packaging contamination. Methods A two-part study was conducted to measure the presence of 5-fluorouracil, ifosfamide, cyclophosphamide, docetaxel and paclitaxel using surrogate markers for external drug packaging. In Part I, 10 drug distributor shipping totes designated for transport of hazardous drugs provided a snapshot view of contamination from regular use and transit in and out of the pharmacy. An additional two totes designated for transport of non-hazardous drugs served as controls. In Part II, old carousel storage bins (i.e. those in use pre-study) were wiped for snapshot view of hazardous drug contamination on storage bins. New carousel storage bins were then put into use for storage of the five tested drugs and used for routine storage and inventory maintenance activities. Carousel bins were wiped at time intervals 0, 8, 16 and 52 weeks to measure surface contamination. Results Two of the 10 hazardous shipping totes were contaminated. Three of the five-old carousel bins were contaminated with cyclophosphamide. One of the old carousel bins was also contaminated with ifosfamide. There were no detectable levels of hazardous drugs on any of the new storage bins at time 0, 8 or 16 weeks. However, at the Week 52, there was a detectable level of 5-FU present in the 5-FU carousel bin. Conclusions Contamination of the surrogate markers suggests that external packaging for hazardous drugs is contaminated, either during the manufacturing process or during routine chain of custody activities. These results demonstrate that occupational exposure may occur due to contamination from shipping totes and storage bins, and that handling practices including use of personal protective equipment is warranted.

  12. [Observation of topography and analysis of surface contamination of titanium implant after roughness treatment].

    Science.gov (United States)

    Cao, Hongdan; Yang, Xiaodong; Wu, Dayi; Zhang, Xingdong

    2007-04-01

    The roughness treatment of dental implant surface could improve the bone bonding and increase the success rate of implant, but the difference of diverse treatments is still unknown. In this study using scanning electron microscopy (SEM), energy disperse spectrometer (EDS) and the test of contact angle, we studied the microstructure, surface contamination and surface energy, and hence conducted a comparative analysis of the following surface roughness treatments: Polished Treatment (PT), Sandblasting with Alumina(SA), Sandblasting with Aluminia and Acid-etched (SAA), Sandblasting with Titanium Acid-etched (STA), Electro-erosion Treatment(ET). The result of SEM showed that the surface displayed irregularities after roughness treatments and that the surface properties of different roughness treatments had some distinctions. SAA and SA had some sharp edges and protrutions; the STA showed a regular pattern like honeycomb, but the ET sample treated by electric erosion exhibited the deeper pores of different sizes and the pores with a perforated secondary structure. The EDS indicated that the surface was contaminated after the treatment with foreign materials; the SA surface had some embedded contaminations even after acid etching. The measurement of water contact angle indicated that the morphology correlated with the surface treatments. These findings suggest that the distinction of surface structure and composition caused by different treatments may result in the disparity in biological behavior of dental implant.

  13. Salinization and arsenic contamination of surface water in southwest Bangladesh.

    Science.gov (United States)

    Ayers, John C; George, Gregory; Fry, David; Benneyworth, Laura; Wilson, Carol; Auerbach, Leslie; Roy, Kushal; Karim, Md Rezaul; Akter, Farjana; Goodbred, Steven

    2017-09-11

    To identify the causes of salinization and arsenic contamination of surface water on an embanked island (i.e., polder) in the tidal delta plain of SW Bangladesh we collected and analyzed water samples in the dry (May) and wet (October) seasons in 2012-2013. Samples were collected from rice paddies (wet season), saltwater ponds used for brine shrimp aquaculture (dry season), freshwater ponds and tidal channels (both wet and dry season), and rainwater collectors. Continuous measurements of salinity from March 2012 to February 2013 show that tidal channel water increases from ~0.15 ppt in the wet season up to ~20 ppt in the dry season. On the polder, surface water exceeds the World Health Organization drinking water guideline of 10 μg As/L in 78% of shrimp ponds and 27% of rice paddies, raising concerns that produced shrimp and rice could have unsafe levels of As. Drinking water sources also often have unsafe As levels, with 83% of tubewell and 43% of freshwater pond samples having >10 μg As/L. Water compositions and field observations are consistent with shrimp pond water being sourced from tidal channels during the dry season, rather than the locally saline groundwater from tubewells. Irrigation water for rice paddies is also obtained from the tidal channels, but during the wet season when surface waters are fresh. Salts become concentrated in irrigation water through evaporation, with average salinity increasing from 0.43 ppt in the tidal channel source to 0.91 ppt in the rice paddies. Our observations suggest that the practice of seasonally alternating rice and shrimp farming in a field has a negligible effect on rice paddy water salinity. Also, shrimp ponds do not significantly affect the salinity of adjacent surface water bodies or subjacent groundwater because impermeable shallow surface deposits of silt and clay mostly isolate surface water bodies from each other and from the shallow groundwater aquifer. Bivariate plots of conservative element

  14. Removable coating for contamination protection of concrete surface

    International Nuclear Information System (INIS)

    Brambilla, G.; Beaulardi, L.

    1985-01-01

    In order to research protective coatings for concrete surfaces, assuring an effective protection against contamination and that it be easily removed before dismantling the structures, commercial stripping paints have been characterized for their conventional and nuclear properties: water and chemicals, abrasion, impact, tensile stress resistance, stripping capacity, decontaminability. The protective power of the coatings against contamination has been checked by recording the surface activity before and after stripping the paint film: the activity filtered through the coating was, in any case, very low (< 1% of the deposited activity). Indications from large scale application of a stripping paint in NUCLEO (Rome) establishments and technical evaluation of the possible utilization of removable coatings in the CAORSO Nuclear Power Station, are also reported

  15. Artefacts for optical surface measurement

    Science.gov (United States)

    Robson, Stuart; Beraldin, J.-Angelo; Brownhill, Andrew; MacDonald, Lindsay

    2011-07-01

    Flexible manufacturing technologies are supporting the routine production of components with freeform surfaces in a wide variety of materials and surface finishes. Such surfaces may be exploited for both aesthetic and performance criteria for a wide range of industries, for example automotive, aircraft, small consumer goods and medial components. In order to ensure conformance between manufactured part and digital design it is necessary to understand, validate and promote best practice of the available measurement technologies. Similar, but currently less quantifiable, measurement requirements also exist in heritage, museum and fine art recording where objects can be individually hand crafted to extremely fine levels of detail. Optical 3D measurement systems designed for close range applications are typified by one or more illumination sources projecting a spot, line or structured light pattern onto a surface or surfaces of interest. Reflections from the projected light are detected in one or more imaging devices and measurements made concerning the location, intensity and optionally colour of the image. Coordinates of locations on the surface may be computed either directly from an understanding of the illumination and imaging geometry or indirectly through analysis of the spatial frequencies of the projected pattern. Regardless of sensing configuration some independent means is necessary to ensure that measurement capability will meet the requirements of a given level of object recording and is consistent for variations in surface properties and structure. As technologies mature, guidelines for best practice are emerging, most prominent at the current time being the German VDI/VDE 2634 and ISO/DIS 10360-8 guidelines. This considers state of the art capabilities for independent validation of optical non-contact measurement systems suited to the close range measurement of table top sized manufactured or crafted objects.

  16. Measurement of Radioactive Contamination on Work Clothing of Workers Engaged in Decontamination Operations

    Science.gov (United States)

    Tsujimura, Norio; Yoshida, Tadayoshi; Hoshi, Katsuya

    To rationally judge the necessity of the contamination screening measurements required in the decontamination work regulations, a field study of the surface contamination density on the clothing of the workers engaged in decontamination operations was performed. The clothing and footwear of 20 workers was analyzed by high-purity germanium (HPGe) gamma-ray spectroscopy. The maximum radiocesium activities (134Cs + 137Cs) observed were 3600, 1300, and 2100 Bq for the work clothing, gloves, and boots, respectively, and the derived surface contamination densities were below the regulatory limit of 40 Bq/cm2. The results of this field study suggest that the upper bounds of the surface contamination density on the work clothing, gloves, and boots are predictable from the maximum soil loading density on the surface of clothing and footwear and the radioactivity concentration in soil at the site.

  17. Measurement of radioactive contamination on work clothing of workers engaged in decontamination operations

    International Nuclear Information System (INIS)

    Tsujimura, Norio; Yoshida, Tadayoshi; Hoshi, Katsuya

    2016-01-01

    To rationally judge the necessity of the contamination screening measurements required in the decontamination work regulations, a field study of the surface contamination density on the clothing of the workers engaged in decontamination operations was performed. The clothing and footwear of 20 workers was analyzed by high-purity germanium (HPGe) gamma-ray spectroscopy. The maximum radiocesium activities ("1"3"4Cs + "1"3"7Cs) observed were 3600, 1300, and 2100 Bq for the work clothing, gloves, and boots, respectively, and the derived surface contamination densities were below the regulatory limit of 40 Bq/cm"2. The results of this field study suggest that the upper bounds of the surface contamination density on the work clothing, gloves, and boots are predictable from the maximum soil loading density on the surface of clothing and footwear and the radioactivity concentration in soil at the site. (author)

  18. Modeling Groundwater-Surface Water Interaction and Contaminant Transport of Chlorinated Solvent Contaminated Site

    Science.gov (United States)

    Yimer Ebrahim, Girma; Jonoski, Andreja; van Griensven, Ann; Dujardin, Juliette; Baetelaan, Okke; Bronders, Jan

    2010-05-01

    Chlorinated-solvent form one of the largest groups of environmental chemicals. Their use and misuse in industry have lead to a large entry of these chemicals into the environment, resulting in widespread dissemination and oftentimes environmental contamination. Chlorinated solvent contamination of groundwater resources has been widely reported. For instance, there has been much interest in the assessment of these contaminant levels and their evolutions with time in the groundwater body below the Vilvoorde-Machelen industrial area (Belgium). The long industrial history of the area has lead to complex patterns of pollution from multiple sources and the site has been polluted to the extent that individual plumes are not definable any more. Understanding of groundwater/surface water interaction is a critical component for determining the fate of contaminant both in streams and ground water due to the fact that groundwater and surface water are in continuous dynamic interaction in the hydrologic cycle. The interaction has practical consequences in the quantity and quality of water in either system in the sense that depletion and/or contamination of one of the system will eventually affect the other one. The transition zone between a stream and its adjacent aquifer referred to as the hyporheic zone plays a critical role in governing contaminant exchange and transformation during water exchange between the two water bodies. The hyporheic zone of Zenne River ( the main receptor ) is further complicated due to the fact that the river banks are artificially trained with sheet piles along its reach extending some 12 m below the surface. This study demonstrates the use of MODFLOW, a widely used modular three-dimensional block-centred finite difference, saturated flow model for simulating the flow and direction of movement of groundwater through aquifer and stream-aquifer interaction and the use of transport model RT3D, a three-dimensional multi-species reactive transport model

  19. Removal of Microbial Contamination from Surface by Plasma

    Science.gov (United States)

    Feng, Xinxin; Liu, Hongxia; Shen, Zhenxing; Wang, Taobo

    2018-01-01

    Microbial contamination is closely associated with human and environmental health, they can be tested on food surfaces, medical devices, packing material and so on. In this paper the removal of the microbial contamination from surface using plasma treatment is investigated. The Escherichia coli (E. coli) has been chosen as a bio-indicator enabling to evaluate the effect of plasma assisted microbial inactivation. Oxygen gas was as the working gas. The plasma RF power, plasma exposition time, gas flow and the concentration of organic pollutant were varied in order to see the effect of the plasma treatment on the Gram-negative germ removal. After the treatment, the microbial abatement was evaluated by the standard plate count method. This proved a positive effect of the plasma treatment on Gram-negative germ removal. The kinetics and mathematical model of removal were studied after plasma treatment, and then the removing course of E. coli was analyzed. This work is meaningful for deepening our understanding of the fundamental scientific principles regarding microbial contamination from surface by plasma.

  20. Surface dose extrapolation measurements with radiographic film

    International Nuclear Information System (INIS)

    Butson, Martin J; Cheung Tsang; Yu, Peter K N; Currie, Michael

    2004-01-01

    Assessment of surface dose delivered from radiotherapy x-ray beams for optimal results should be performed both inside and outside the prescribed treatment fields. An extrapolation technique can be used with radiographic film to perform surface dose assessment for open field high energy x-ray beams. This can produce an accurate two-dimensional map of surface dose if required. Results have shown that the surface percentage dose can be estimated within ±3% of parallel plate ionization chamber results with radiographic film using a series of film layers to produce an extrapolated result. Extrapolated percentage dose assessment for 10 cm, 20 cm and 30 cm square fields was estimated to be 15% ± 2%, 29% ± 3% and 38% ± 3% at the central axis and relatively uniform across the treatment field. The corresponding parallel plate ionization chamber measurements are 16%, 27% and 37%, respectively. Surface doses are also measured outside the treatment field which are mainly due to scattered electron contamination. To achieve this result, film calibration curves must be irradiated to similar x-ray field sizes as the experimental film to minimize quantitative variations in film optical density caused by varying x-ray spectrum with field size. (note)

  1. Explosive Contamination from Substrate Surfaces: Differences and Similarities in Contamination Techniques Using RDX and C-4

    Science.gov (United States)

    Miller, C. J.; Yoder, T. S.

    2010-06-01

    Explosive trace detection equipment has been deployed to airports for more than a decade. During this time, the need for standardized procedures and calibrated trace amounts for ensuring that the systems are operating properly and detecting the correct explosive has been apparent but a standard representative of a fingerprint has been elusive. Standards are also necessary to evaluate instrumentation in the laboratories during development and prior to deployment to determine sample throughput, probability of detection, false positive/negative rates, ease of use by operator, mechanical and/or software problems that may be encountered, and other pertinent parameters that would result in the equipment being unusable during field operations. Since many laboratories do not have access to nor are allowed to handle explosives, the equipment is tested using techniques aimed at simulating the actual explosives fingerprint. This laboratory study focused on examining the similarities and differences in three different surface contamination techniques that are used to performance test explosive trace detection equipment in an attempt to determine how effective the techniques are at replicating actual field samples and to offer scenarios where each contamination technique is applicable. The three techniques used were dry transfer deposition of standard solutions using the Transportation Security Laboratory’s (TSL) patented dry transfer techniques (US patent 6470730), direct deposition of explosive standards onto substrates, and fingerprinting of actual explosives onto substrates. RDX was deposited on the surface of one of five substrates using one of the three different deposition techniques. The process was repeated for each substrate type using each contamination technique. The substrate types used were: 50% cotton/50% polyester as found in T-shirts, 100% cotton with a smooth surface such as that found in a cotton dress shirt, 100% cotton on a rough surface such as that

  2. Measurement techniques for radiological characterization of contaminated sites

    Energy Technology Data Exchange (ETDEWEB)

    Loos, M

    1996-09-18

    Once the decision is taken to characterize a contaminated site, appropriate measurement techniques must be selected. The choice will depend on the available information, on the nature and extent of the contamination, as well as on available resources (staff and budget). Some techniques are described on the basis of examples of characterization projects (e.g. Olen area in Belgium).

  3. Organization of work for prevention of propagation of radioactive contamination, for decontamination of the premise surfaces and individual protective means in case of radiation accident

    International Nuclear Information System (INIS)

    Klochkov, V.N.; Vas'kin, A.G.; Filatova, V.M.

    1995-01-01

    Radiation accident results in radioactive contamination of the surface, clothes and other property. If proper measures are taken, it will prevent propagation of contamination. Decontamination of surfaces - is a complicated and tedious process. The paper has examined the measures of organization and technical aspects of prevention of propagation of radioactive contamination. Methods of decontamination of internal surfaces of premises are demonstrated, organization of the individual protective means is determined. 9 refs

  4. Laser assisted decontamination of metal surface: Evidence of increased surface absorptivity due to field enhancement caused by transparent/semi-transparent contaminant particulates

    International Nuclear Information System (INIS)

    Nilaya, J. Padma; Biswas, Dhruba J.

    2010-01-01

    Small signal absorption measurements of the incident coherent radiation by the metal surface have revealed an increase in the absorption by the surface in presence of transparent/semi-transparent particulates on it. This effect, identified as field enhanced surface absorption, has been found to increase with reduction in the average particulate size. Consequently higher laser assisted removal efficiency of contamination from a metal surface has been observed for smaller contaminant particulates. These measurements have been carried out utilizing coherent radiations of two different wavelengths so chosen that for one the particulates are totally transparent while for the other they are partially transparent.

  5. Contamination measurements on persons after a nuclear accident

    International Nuclear Information System (INIS)

    Maushart, R.

    1992-01-01

    The purpose of contamination measurements after accidents is threefold: to detect and localize contaminations; to determine the level of contamination as a base for medical decisions; and to check the scope and efficiency of the decontamination measures. Persons involved in accidents should never measure their contamination themselves. The radiation protection personnel, whether it belongs to the medical team or to the disaster control squads, must be familiar with the measuring instruments and experienced in handling these instruments. A high priority has to be placed on training and constant practice. The monitors used must meet the special requirements of an emergency situation. This includes resistance against environmental factors - temperature, humidity, vibrations - as well as the simplicity of handling the instrument, and the clear presentation of the results. (author)

  6. Surface flow measurements from drones

    Science.gov (United States)

    Tauro, Flavia; Porfiri, Maurizio; Grimaldi, Salvatore

    2016-09-01

    Drones are transforming the way we sense and interact with the environment. However, despite their increased capabilities, the use of drones in geophysical sciences usually focuses on image acquisition for generating high-resolution maps. Motivated by the increasing demand for innovative and high performance geophysical observational methodologies, we posit the integration of drone technology and optical sensing toward a quantitative characterization of surface flow phenomena. We demonstrate that a recreational drone can be used to yield accurate surface flow maps of sub-meter water bodies. Specifically, drone's vibrations do not hinder surface flow observations, and velocity measurements are in agreement with traditional techniques. This first instance of quantitative water flow sensing from a flying drone paves the way to novel observations of the environment.

  7. Use of a surface contamination survey simulation program and its effects

    International Nuclear Information System (INIS)

    Onuma, Isamu; Kobayashi, Makoto; Umehara, Takashi; Shimizu, Isamu

    2012-01-01

    A computer simulation program has been developed to train the practitioners examining the surface contamination of objects to be carried out from the controlled area. The efficiency of the examination depends significantly on the proficiency in radiation measurement and proper perception of contamination. It has been demonstrated through the usage of the program that it helps practitioners very much suggest their weakness and promote their skill in examination. The program runs on the commonly used personal computers and users can easily experience the virtual examination by sweeping and cricking the mouse. The program is useful to radiation protection practitioners not only beginners but also experts. (author)

  8. Dosimetry of skin-contact exposure to tritium gas contaminated surfaces

    International Nuclear Information System (INIS)

    Legare, M.

    1990-12-01

    The radiological hazards from tritium are usually associated with exposure to tritium oxide either by inhalation, ingestion or permeation through skin. However, exposure from skin contact with tritium gas contaminated surfaces represents a different radiological hazard in tritium removal facilities and future fusion power plants. Previous experiments on humans and more recent experiments on hairless rats at Chalk River Laboratories have shown that when a tritium gas-contaminated surface is brought into contact with intact skin, high concentrations of organically-bound tritium in urine and skin are observed which were not seen from single tritiated water (liquid or vapour form) contamination. The results of the rat experiments, which involved measurements of tritium activity in urine and skin, after contact with contaminated stainless steel, are described. These results are also compared to previous data from human experiments. The effect of various exposure conditions and different contaminated surfaces such as brass, aluminum and glass are analysed and related to the results from contaminated stainless steel exposure. Dosimetric models are being developed in order to improve the basis for dose assessment for this mode of tritium uptake. The presently studied model is explained along with the assumptions and methods involved in its derivation. The features of 'STELLA', the software program used to implement the model, are discussed. The methods used to estimate skin and whole body dose from a model are demonstrated. Finally, some experiments for improving the accuracy of the model are proposed. Briefly, this study compares the results from animal and human experiments as well as different exposure conditions, and determines the range of whole body and skin dose that may be involved from skin-contact intake. This information is essential for regulatory purposes particularly in the derivation of doses for skin-contact contamination. (15 figs., 7 tabs., 29 refs.)

  9. Method of measuring surface density

    International Nuclear Information System (INIS)

    Gregor, J.

    1982-01-01

    A method is described of measuring surface density or thickness, preferably of coating layers, using radiation emitted by a suitable radionuclide, e.g., 241 Am. The radiation impinges on the measured material, e.g., a copper foil and in dependence on its surface density or thickness part of the flux of impinging radiation is reflected and part penetrates through the material. The radiation which has penetrated through the material excites in a replaceable adjustable backing characteristic radiation of an energy close to that of the impinging radiation (within +-30 keV). Part of the flux of the characteristic radiation spreads back to the detector, penetrates through the material in which in dependence on surface density or thickness of the coating layer it is partly absorbed. The flux of the penetrated characteristic radiation impinging on the face of the detector is a function of surface density or thickness. Only that part of the energy is evaluated of the energy spectrum which corresponds to the energy of characteristic radiation. (B.S.)

  10. Radiation contamination monitors

    International Nuclear Information System (INIS)

    Kato, Tsutomu; Iba, Hiroshi; Sato, Hiroshi

    1999-01-01

    To make sure of no contamination on people, used articles and working uniforms coming out of the radiation controlled area, nuclear power plants are equipped with radioactive contamination monitors. This paper outlines the basic specifications and advantages of our personnel surface contamination monitors to inspect whole-body surface contamination of people coming out, article surface contamination monitors to inspect the surface and inside contamination of used articles brought out, laundry monitors to inspect surface contamination of working uniforms used in the area before and after a wash, and whole-body counters to inspect and measure the internal contamination of a person out of the area. (author)

  11. Bacteria contamination of touch surfaces in Polish hospital wards

    Directory of Open Access Journals (Sweden)

    Anna Różańska

    2017-08-01

    Full Text Available Background: The objective of the study has been to evaluate the pathogenic bacteria contamination of touch surfaces in hospital wards. Material and Methods: Samples were taken from frequently touched surfaces in the hospital environment in 13 units of various types. Culturing was carried out on solid blood agar and in growth broth (tryptic soy broth – TSB. Species identification was performed using the analytical profile index (API biochemical testing and confirmed with matrix assisted laser desorption ionization time-flight mass spectrometry (MALDI-TOF-MS system. Results: The total of 161 samples were taken for the study. Fifty-two of them, after 24 h of culture on a solid medium, demonstrated bacterial growth and further 60 samples had growth after prior multiplication in TSB. Overall, 69.6% of samples exhibited growth of 19 bacterial species. Pathogenic species – representing indicator organisms of efficiency of hospital cleaning – was demonstrated by 21.4% of samples. Among them Acinetobacter spp., Enterocococci spp. and Staphylococcus aureus were identified. Coagulase-negative staphylococci (CNS were predominant. The proportion of various groups of bacteria significantly varied in respective hospitals, and in various types of wards. Disturbing observation is a large proportion of resistance of isolated CNS strains as a potential reservoir of resistance genes. Conclusions: The results show that touch surfaces in hospital units are contaminated by both potentially pathogenic and pathogenic bacterial species. In connection with the reported, also in Poland, frequent omission or incorrect execution of hand hygiene by hospital staff, and probably patients, touch surfaces still constitute important reservoir of pathogenic bacteria. Improving hand hygiene compliance of health-care workers with recommendations is necessary for increasing biological safety of hospital environment. Med Pr 2017;68(3:459–467

  12. The technique for determination of surface contamination by uranium on U3Si2-Al plate-type fuel elements

    International Nuclear Information System (INIS)

    Li Shulan; He Fengqi; Wang Qingheng; Han Jingquan

    1993-04-01

    The NDT method for determining the surface contamination by uranium on U 3 Si 2 -Al plate-type fuel elements, the process of standard specimen preparation and the graduation curve are described. The measurement results of U 3 Si 2 -Al plate-type fuel elements show that the alpha counting method to measure the surface contamination by uranium on fuel plate is more reliable. The UB-1 type surface contamination meter, which was recently developed, has many advantages such as high sensitivity to determine the uranium pollution, short time in measuring, convenience for operation, and the minimum detectable amount of uranium is 5 x 10 -10 g/cm 2 . The measuring device is controlled by a microcomputer. Besides data acquisition and processing, it has functions of statistics, output data on terminal or to printer and alarm. The procedures of measurement are fully automatic. All of these will meet the measuring needs in batch process

  13. Detecting buried radium contamination using soil-gas and surface-flux radon meaurements

    International Nuclear Information System (INIS)

    Karp, K.E.

    1988-06-01

    The Technical Measurements Center (TMC) has investigated the effectiveness of using radon soil-gas under surface-flux measurments to locate radium contamination that is buried sufficiently deep to be undetectable by surface gamma methods. At the first test site studied, an indication of a buried source was revealed by mapping anomalous surface-flux and soil-gas concentrations in the near surface overburden. The mapped radon anomalies were found to correspond in rough outline to the shape of the areal extent of the deposit as determined by borehole gamma-ray logs. The 5.9pCi/g radium deposit, buried 2 feet below the surface, went undetected by conventional surface gamma measurements. Similar results were obtained at the second test site where radon and conventional surface gamma measurements were taken in an area having radium concentrations ranging from 13.3 to 341.0 pCi/g at a depth of 4 feet below the surface. The radon methods were found to have a detection limit for buried radium lower than that of the surface gamma methods, as evidenced by the discovery of the 13.3 pCi/g deposit which went undetected by the surface gamma methods. 15 refs., 33 figs., 8 tabs

  14. Evaluation of surface contamination due to alpha using large area contamination monitors

    International Nuclear Information System (INIS)

    Raghavayya, M.

    1998-01-01

    Radioactive contamination at work places is evaluated routinely using either the swipe sampling technique or a contamination monitor. Commercially available alpha probes used for the purpose are usually circular and have a face diameter of 50 or 100 mm. Square faced probes are also available. A thin aluminized mylar membrane of thickness 0.45 to 0.9 mg.cm -2 is used to screen the phosphor in the alpha probe to protect it from external light. The membrane cuts off more alphas from low energy emitters than from higher energy alpha emitters. Moreover the response of the detector for alphas originating at all points under the detector face is not uniform, especially when the large area alpha monitors are used. These factors can introduce errors as high as 40% into the measurements. This paper aims to quantify these errors and describe a procedure to overcome the limitations. (author)

  15. A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

    International Nuclear Information System (INIS)

    Gao Baohong; Liu Yuling; Wang Chenwei; Wang Shengli; Zhou Qiang; Tan Baimei; Zhu Yadong

    2010-01-01

    This paper presents a new cleaning process using boron-doped diamond (BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces. The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide, pyrophosphate peroxide can oxidize organic contaminants, and pyrophosphate peroxide is deoxidized into pyrophosphate. Pyrophosphate, a good complexing agent, can form a metal complex, which is a structure consisting of a copper ion, bonded to a surrounding array of two pyrophosphate anions. Three polished wafers were immersed in the 0.01 mol/L CuSO 4 solution for 2 h in order to make comparative experiments. The first one was cleaned by pyrophosphate peroxide, the second by RCA (Radio Corporation of America) cleaning, and the third by deionized (DI) water. The XPS measurement result shows that the metallic contaminants on wafers cleaned by the RCA method and by pyrophosphate peroxide is less than the XPS detection limits of 1 ppm. And the wafer's surface cleaned by pyrophosphate peroxide is more efficient in removing organic carbon residues than RCA cleaning. Therefore, BDD film anode electrochemical oxidation can be used for microelectronics cleaning, and it can effectively remove organic contaminants and metallic contaminants in one step. It also achieves energy saving and environmental protection. (semiconductor technology)

  16. Contamination measurements with quadrupole mass spectrometer

    International Nuclear Information System (INIS)

    Bohatka, S.; Berecz, I.; Langer, G.

    1981-01-01

    A sensitive quadrupole mass spectrometer of our own construction was used for different purity measurements. The analysis of gases in operating rooms showed a 1 ppm-10 5 ppm concentration of narcotics and helped to develop an effective and cheap method for regenerating narcotic filters. We regularly control the gases used in radioactive pollution measurements by internal GM counters and in radiocarbon dating technique. Combustion products and the gases of a fermenter are investigated for industrial application. (orig.) [de

  17. Recommendations for determining the surface contamination of the skin and estimating radiation exposure of the skin after contamination

    International Nuclear Information System (INIS)

    1989-01-01

    The recommendations are applicable to the determination of surface contaminations of the skin and to the estimation of the expected radiation exposure of the skin of contaminated persons. According to the present recommendations, the radiation exposure can only be estimated for the intact and healthy skin

  18. Detection of microbial contaminations in drinking water using ATP measurements – evaluating potential for online monitoring

    DEFF Research Database (Denmark)

    Vang, Óluva Karin; Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    2011-01-01

    There is an increasing call for fast and reliable methods for continuous monitoring of microbial drinking water quality in order to protect public health. The potential for Adenosine triphosphate (ATP) measurements as a real-time analysis for continuous monitoring of microbial drinking water...... quality was investigated through simulation of two contamination scenarios, i.e. drinking water contaminated with waste water and surface water at various concentrations. With ATP measurements it was possible to detect waste water diluted 1000-10,000 times in drinking water depending on sensitivity...... of reagent kit. Surface water diluted 100-1000 times was detected in drinking water with ATP measurements. ATP has the potential as an early warning tool, especially in the period when the contamination concentration is high. 2011 © American Water Works Association AWWA WQTC Conference Proceedings All Rights...

  19. New miniaturized alpha/beta spectrometric system for the surface contamination monitoring and radon personal dosimeter

    International Nuclear Information System (INIS)

    Streil, T.; Oeser, V.; Holfeld, G.

    1998-01-01

    The heart of the new miniaturized alpha/beta spectroscopic system is a Smart Card MCA having a 12 bit resolution and a 32 bit memory for each channel with the size of a cheque card. The system consists of a single or up to 12 alpha spectrometers in a battery powered casing with connectors for direct detector/amplifier module plugging. Surface contamination in the order of 1 Bq/cm 2 of 239 Pu can be measured. (M.D.)

  20. Device for determining the gross weight, dose rate, surface contamination and/or nuclide inventory

    International Nuclear Information System (INIS)

    1987-01-01

    Barrels with low nuclide inventories (about 1E6 Bq) and with high inventories (1E13 Bq) are inspected with the barrel inspection system. The system provides a rotating plate, which is part of some scales and a measuring sensor arrangement for this purpose. The surface contamination and nuclide inventories of the 200 litre barrels can be calculated from the weight and radiation detector values. (DG) [de

  1. Effect of Surface Contaminants Remained on the Blasted Surface on Epoxy Coating Performance and Corrosion Resistance

    International Nuclear Information System (INIS)

    Baek, Kwang Ki; Park, Chung Seo; Kim, Ki Hong; Chung, Mong Kyu; Park, Jin Hwan

    2006-01-01

    One of the critical issues in the coating specification is the allowable limit of surface contaminant(s) - such as soluble salt(s), grit dust, and rust - after grit blasting. Yet, there is no universally accepted data supporting the relationship between the long-term coating performance and the amount of various surface contaminants allowed after grit blasting. In this study, it was attempted to prepare epoxy coatings applied on grit-blasted steel substrate dosed with controlled amount of surface contaminants - such as soluble salt(s), grit dust, and rust. Then, coating samples were subjected to 4,200 hours of cyclic test(NORSOK M-501), which were then evaluated in terms of resistance to rust creepage, blistering, chalking, rusting, cracking and adhesion strength. Additional investigations on the possible damage at the paint/steel interface were carried out using an Electrochemical Impedance Spectroscopy(EIS) and observations of under-film-corrosion. Test results suggested that the current industrial specifications were well matched with the allowable degree of rust, whereas the allowable amount of soluble salt and grit dust after grit blasting showed a certain deviation from the specifications currently employed for fabrication of marine vessels and offshore facilities

  2. Indoor and Outdoor Surface-Growing Fungi Contamination at Higher Institutional Buildings in a Malaysian University

    Science.gov (United States)

    Er, C. M.; Sunar, N. M.; Leman, A. M.; Khalid, A.; Ali, R.; Zaidi, E.; Azhar, A. T. S.

    2018-04-01

    Surface-growing indoor and outdoor fungi were assessed using swabbing method to investigate the indoor contamination. The painted wall surface samples were collected from two institutional buildings (B1 and B2) of a university in southern Peninsular Malaysia; indoors and outdoors. The mould concentrations varied widely between indoor and outdoor surface samples of both buildings. The total indoor surface-growing mould concentration (8776.49 CFU/cm2) is significantly higher (pair quality parameters (relative humidity, temperature and air velocity) were also measured indoors and outdoors during the study and violation of the guideline provided by ICOP-IAQ 2010 were proven in indoor environment in both buildings. The results of this assessment showed that the indoor environments of both institutional buildings were contaminated by the surface-growing mould. It also suggested the faulty designs and/or usages of building material in these institutional buildings contributed toward the contamination. An innovative solution is needed to correct the problems.

  3. Conformation evolution of oil contaminants onto aluminum oxide surface in aqueous solution: The effect of surface coverage

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wenkun; Liu, Haitao, E-mail: xwk584523412@126.com; Sun, Yazhou; Fu, Hongya; Liang, Yingchun

    2017-01-15

    Highlights: • The dynamic conformational change of oil contaminations, at various surface coverages onto perfect α-Al{sub 2}O{sub 3}(0001) surface in aqueous solution is given. • The effect of surface coverage of oil molecules on the driving forces for the conformational change of oil contaminations is described. • The effect of interfacial water on the conformational change and even detachment of oil contaminations is considered. - Abstract: The microscopic conformational change process of oil contaminants adhered onto perfect α-Al{sub 2}O{sub 3} (0001) surface in aqueous solution was investigated by using all-atom classic molecular dynamics simulations. The change in removal mechanism of oil contaminants induced by surface coverage (surface area per molecule) was emphatically explored. Our simulation results strongly reveal that the increase in oil surface coverage induces an evident difference in microscopic detachment processes of oil contaminants. At a low surface coverage, oil contaminants can be thoroughly detached from solid surface. The whole detachment process could be divided into multi stages, including conformational change of oil contaminants on solid surface, dynamic motion of those in bulk solution and rapid migration of those from bulk solution to air/water interface. With surface coverage increasing, water diffusion becomes the key to induce conformational change and promote the detachment of oil contaminants. When oil surface coverage exceeds a threshold value, oil contaminants also undertake an evident conformational change process exhibiting typical characteristics but an incomplete detachment process occurs. All findings of the present study are helpful for the interpretation of the removal mechanism of oil contaminants on solid surface.

  4. Advanced LWIR hyperspectral sensor for on-the-move proximal detection of liquid/solid contaminants on surfaces

    Science.gov (United States)

    Giblin, Jay P.; Dixon, John; Dupuis, Julia R.; Cosofret, Bogdan R.; Marinelli, William J.

    2017-05-01

    Sensor technologies capable of detecting low vapor pressure liquid surface contaminants, as well as solids, in a noncontact fashion while on-the-move continues to be an important need for the U.S. Army. In this paper, we discuss the development of a long-wave infrared (LWIR, 8-10.5 μm) spatial heterodyne spectrometer coupled with an LWIR illuminator and an automated detection algorithm for detection of surface contaminants from a moving vehicle. The system is designed to detect surface contaminants by repetitively collecting LWIR reflectance spectra of the ground. Detection and identification of surface contaminants is based on spectral correlation of the measured LWIR ground reflectance spectra with high fidelity library spectra and the system's cumulative binary detection response from the sampled ground. We present the concepts of the detection algorithm through a discussion of the system signal model. In addition, we present reflectance spectra of surfaces contaminated with a liquid CWA simulant, triethyl phosphate (TEP), and a solid simulant, acetaminophen acquired while the sensor was stationary and on-the-move. Surfaces included CARC painted steel, asphalt, concrete, and sand. The data collected was analyzed to determine the probability of detecting 800 μm diameter contaminant particles at a 0.5 g/m2 areal density with the SHSCAD traversing a surface.

  5. Accuracy Analysis of a Robotic Radionuclide Inspection and Mapping System for Surface Contamination

    International Nuclear Information System (INIS)

    Mauer, Georg F.; Kawa, Chris

    2008-01-01

    The mapping of localized regions of radionuclide contamination in a building can be a time consuming and costly task. Humans moving hand-held radiation detectors over the target areas are subject to fatigue. A contamination map based on manual surveys can contain significant operator-induced inaccuracies. A Fanuc M16i light industrial robot has been configured for installation on a mobile aerial work platform, such as a tall forklift. When positioned in front of a wall or floor surface, the robot can map the radiation levels over a surface area of up to 3 m by 3 m. The robot's end effector is a commercial alpha-beta radiation sensor, augmented with range and collision avoidance sensors to ensure operational safety as well as to maintain a constant gap between surface and radiation sensors. The accuracy and repeatability of the robotically conducted contamination surveys is directly influenced by the sensors and other hardware employed. This paper presents an in-depth analysis of various non-contact sensors for gap measurement, and the means to compensate for predicted systematic errors that arise during the area survey scans. The range sensor should maintain a constant gap between the radiation counter and the surface being inspected. The inspection robot scans the wall surface horizontally, moving down at predefined vertical intervals after each scan in a meandering pattern. A number of non-contact range sensors can be employed for the measurement of the gap between the robot end effector and the wall. The nominal gap width was specified as 10 mm, with variations during a single scan not to exceed ± 2 mm. Unfinished masonry or concrete walls typically exhibit irregularities, such as holes, gaps, or indentations in mortar joints. These irregularities can be sufficiently large to indicate a change of the wall contour. The responses of different sensor types to the wall irregularities vary, depending on their underlying principles of operation. We explored

  6. MULTIPLE IMAGING TECHNIQUES DEMONSTRATE THE MANIPULATION OF SURFACES TO REDUCE BACTERIAL CONTAMINATION

    Science.gov (United States)

    Surface imaging techniques were combined to determine appropriate manipulation of technologically important surfaces for commercial applications. Stainless steel surfaces were engineered to reduce bacterial contamination, biofilm formation, and corrosion during product processing...

  7. Equipment for measuring contamination of hands with radioactive material

    International Nuclear Information System (INIS)

    Erban, J.; Kleinbauer, K.; Husak, V.; Grigar, O.

    1986-01-01

    The claimed device consists of a scintillation detector mounted in a shielding case consisting of rings. The shielding case is provided with a cavity with an inlet opening lined with polyethylene foil. The cavity shape, shielding and replaceable foil guarantee minimizing the interfering effect of radiation sources in the vicinity and of contamination of the device. Gradually inserting the hand in the cavity or suitably placing the hand can locate contamination of the hand surface. The sensitivity of the device for 125 I and 99 Tc is 200-times higher than that of Geiger-Mueller counter instruments. (M.D.)

  8. Natural Contamination and Surface Flashover on Silicone Rubber Surface under Haze–Fog Environment

    Directory of Open Access Journals (Sweden)

    Ang Ren

    2017-10-01

    Full Text Available Anti-pollution flashover of insulator is important for power systems. In recent years, haze-fog weather occurs frequently, which makes discharge occurs easily on the insulator surface and accelerates insulation aging of insulator. In order to study the influence of haze-fog on the surface discharge of room temperature vulcanized silicone rubber, an artificial haze-fog lab was established. Based on four consecutive years of insulator contamination accumulation and atmospheric sampling in haze-fog environment, the contamination configuration appropriate for RTV-coated surface discharge test under simulation environment of haze-fog was put forward. ANSYS Maxwell was used to analyze the influence of room temperature vulcanized silicone rubber surface attachments on electric field distribution. The changes of droplet on the polluted room temperature vulcanized silicone rubber surface and the corresponding surface flashover voltage under alternating current (AC, direct current (DC positive polar (+, and DC negative polar (− power source were recorded by a high speed camera. The results are as follows: The main ion components from haze-fog atmospheric particles are NO3−, SO42−, NH4+, and Ca2+. In haze-fog environment, both the equivalent salt deposit density (ESDD and non-soluble deposit density (NSDD of insulators are higher than that under general environment. The amount of large particles on the AC transmission line is greater than that of the DC transmission line. The influence of DC polarity power source on the distribution of contamination particle size is not significant. After the deposition of haze-fog, the local conductivity of the room temperature vulcanized silicone rubber surface increased, which caused the flashover voltage reduce. Discharge is liable to occur at the triple junction point of droplet, air, and room temperature vulcanized silicone rubber surface. After the deformation or movement of droplets, a new triple junction

  9. Practical aspects of tritium measurement in ground and surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Nitzsche, O [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik; Hebert, D [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik

    1997-03-01

    Tritium measurements are a powerful tool in hydrological and hydrogeological investigations for detecting mean residence times of several water reservoirs. Due to the low tritium activities in precipitation, ground and surface waters a low level measurement is necessary. Therefore often the liquid scintillation counting after an electrolytic enrichment of water is used. In this paper some practical aspects and problems of measurement are discussed and the problem of contamination in low level laboratories is shown. (orig.)

  10. Potential effects of groundwater and surface water contamination in an urban area, Qus City, Upper Egypt

    Science.gov (United States)

    Abdalla, Fathy; Khalil, Ramadan

    2018-05-01

    The potential effects of anthropogenic activities, in particular, unsafe sewage disposal practices, on shallow groundwater in an unconfined aquifer and on surface water were evaluated within an urban area by the use of hydrogeological, hydrochemical, and bacteriological analyses. Physicochemical and bacteriological data was obtained from forty-five sampling points based on33 groundwater samples from variable depths and 12 surface water samples. The pollution sources are related to raw sewage and wastewater discharges, agricultural runoff, and wastewater from the nearby Paper Factory. Out of the 33 groundwater samples studied, 17 had significant concentrations of NO3-, Cl- and SO42-, and high bacteria counts. Most of the water samples from the wells contained high Fe, Mn, Pb, Zn, Cd, and Cr. The majority of surface water samples presented high NO3- concentrations and high bacteria counts. A scatter plot of HCO3- versus Ca indicates that 58% of the surface water samples fall within the extreme contamination zone, while the others are within the mixing zone; whereas 94% of groundwater samples showed evidence of mixing between groundwater and wastewater. The bacteriological assessment showed that all measured surface and groundwater samples contained Escherichia coli and total coliform bacteria. A risk map delineated four classes of contamination, namely, those sampling points with high (39.3%), moderate (36.3%), low (13.3%), and very low (11.1%) levels of contamination. Most of the highest pollution points were in the middle part of the urban area, which suffers from unmanaged sewage and industrial effluents. Overall, the results demonstrate that surface and groundwater in Qus City are at high risk of contamination by wastewater since the water table is shallow and there is a lack of a formal sanitation network infrastructure. The product risk map is a useful tool for prioritizing zones that require immediate mitigation and monitoring.

  11. Tritium contaminated surface monitoring with a solid - state device

    International Nuclear Information System (INIS)

    Culcer, Mihai; Iliescu, Mariana; Curuia, Marian; Enache, Adrian; Stefanescu, Ioan; Ducu, Catalin; Malinovschi, Viorel

    2004-01-01

    The low energy of betas makes tritium difficult to detect. However, there are several methods used in tritium detection, such as liquid scintillation and ionization chambers. Tritium on or near a surface can be also detected using proportional counters and, recently, solid state devices. The paper presents our results in the design and achievement of a surface tritium monitor using a PIN photodiode as a solid state charged particle detector to count betas emitted from the surface. That method allows continuous, real-time and non-destructively measuring of tritium. (authors)

  12. Environmental survey to assess viral contamination of air and surfaces in hospital settings.

    Science.gov (United States)

    Carducci, A; Verani, M; Lombardi, R; Casini, B; Privitera, G

    2011-03-01

    The presence of pathogenic viruses in healthcare settings represents a serious risk for both staff and patients. Direct viral detection in the environment poses significant technical problems and the indirect indicators currently in use suffer from serious limitations. The aim of this study was to monitor surfaces and air in hospital settings to reveal the presence of hepatitis C virus, human adenovirus, norovirus, human rotavirus and torque teno virus by nucleic acid assays, in parallel with measurements of total bacterial count and haemoglobin presence. In total, 114 surface and 62 air samples were collected. Bacterial contamination was very low (air was 282 cfu/m(3). Overall, 19 (16.7%) surface samples tested positive for viral nucleic acids: one for norovirus, one for human adenovirus and 17 (14.9%) for torque teno virus (TTV). Only this latter virus was directly detected in 10 air samples (16.1%). Haemoglobin was found on two surfaces. No relationship was found between viral, biochemical or bacterial indicators. The data obtained confirm the difficulty of assessing viral contamination using bacterial indicators. The frequent detection of TTV suggests its possible use as an indicator for general viral contamination of the environment. Copyright © 2010 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

  13. Surface and subsurface characterization of uranium contamination at the Fernald environmental management site

    International Nuclear Information System (INIS)

    Schilk, A.J.; Perkins, R.W.; Abel, K.H.; Brodzinski, R.L.

    1993-04-01

    The past operations of uranium production and support facilities at several Department of Energy (DOE) sites have occasionally resulted in the local contamination of some surface and subsurface soils, and the three-dimensional distribution of the uranium at these sites must be thoroughly characterized before any effective remedial protocols can be established. To this end, Pacific Northwest Laboratory (PNL) has been tasked by the DOE's Office of Technology Development with adapting, developing, and demonstrating technologies for the measurement of uranium in surface and subsurface soils at the Fernald Uranium in Soils Integrated Demonstration site. These studies are detailed in this report

  14. Surface Sampling Collection and Culture Methods for Escherichia coli in Household Environments with High Fecal Contamination.

    Science.gov (United States)

    Exum, Natalie G; Kosek, Margaret N; Davis, Meghan F; Schwab, Kellogg J

    2017-08-22

    Empiric quantification of environmental fecal contamination is an important step toward understanding the impact that water, sanitation, and hygiene interventions have on reducing enteric infections. There is a need to standardize the methods used for surface sampling in field studies that examine fecal contamination in low-income settings. The dry cloth method presented in this manuscript improves upon the more commonly used swabbing technique that has been shown in the literature to have a low sampling efficiency. The recovery efficiency of a dry electrostatic cloth sampling method was evaluated using Escherichia coli and then applied to household surfaces in Iquitos, Peru, where there is high fecal contamination and enteric infection. Side-by-side measurements were taken from various floor locations within a household at the same time over a three-month period to compare for consistency of quantification of E. coli bacteria. The dry cloth sampling method in the laboratory setting showed 105% (95% Confidence Interval: 98%, 113%) E. coli recovery efficiency off of the cloths. The field application demonstrated strong agreement of side-by-side results (Pearson correlation coefficient for dirt surfaces was 0.83 ( p samples (Pearson (0.53, p method can be utilized in households with high bacterial loads using either continuous (quantitative) or categorical (semi-quantitative) data. The standardization of this low-cost, dry electrostatic cloth sampling method can be used to measure differences between households in intervention and non-intervention arms of randomized trials.

  15. Wind effected redistribution of surface contamination. Progress report, September 1974--August 1975

    International Nuclear Information System (INIS)

    Amato, A.J.

    1975-01-01

    Theoretical resuspension ratios were computed through the extension of a one-dimensional model used to simulate the wind effected movement of surface contaminants. The surface movement of contamination associated with inhalable size particles was considered in relation to time, space, wind velocity, distance from the source, soil resuspension ratios, and other variables. A computer program was developed to calculate the wind effected distribution of surface contaminants. (U.S.)

  16. Monitoring of Water and Contaminant Migration at the Groundwater-Surface Water Interface

    Science.gov (United States)

    2008-08-01

    seepage is occurring in a freshwater lake environment and to map the lateral extent of any subsurface contamination at the groundwater –surface water ...and Contaminant Migration at the Groundwater -Surface Water Interface August 2008 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public...4. TITLE AND SUBTITLE Monitoring of Water and Contaminant Migration at the Groundwater -Surface Water Interface 5a. CONTRACT NUMBER 5b. GRANT NUMBER

  17. A microscopy approach for in situ inspection of micro-coordinate measurement machine styli for contamination

    Science.gov (United States)

    Feng, Xiaobing; Pascal, Jonathan; Lawes, Simon

    2017-09-01

    During the process of measurement using a micro-coordinate measurement machine (µCMM) contamination gradually builds up on the surface of the stylus tip and affects the dimensional accuracy of the measurement. Regular inspection of the stylus for contamination is essential to determine the appropriate cleaning interval and prevent the dimensional error from becoming significant. However, in situ inspection of a µCMM stylus is challenging due to the size, spherical shape, material and surface properties of a typical stylus. To address this challenge, this study evaluates several non-contact measurement technologies for in situ stylus inspection and, based on those findings, proposes a cost-effective microscopy approach. The operational principle is then demonstrated by an automated prototype, coordinated directly by the CMM software MCOSMOS, with an effective threshold of detection as low as 400 nm and a large field of view and depth of field. The level of contamination on the stylus has been found to increase steadily with the number of measurement contacts made. Once excessive contamination is detected on the stylus, measurement should be stopped and a stylus cleaning procedure should be performed to avoid affecting measurement accuracy.

  18. A microscopy approach for in situ inspection of micro-coordinate measurement machine styli for contamination

    International Nuclear Information System (INIS)

    Feng, Xiaobing; Lawes, Simon; Pascal, Jonathan

    2017-01-01

    During the process of measurement using a micro-coordinate measurement machine (µCMM) contamination gradually builds up on the surface of the stylus tip and affects the dimensional accuracy of the measurement. Regular inspection of the stylus for contamination is essential to determine the appropriate cleaning interval and prevent the dimensional error from becoming significant. However, in situ inspection of a µCMM stylus is challenging due to the size, spherical shape, material and surface properties of a typical stylus. To address this challenge, this study evaluates several non-contact measurement technologies for in situ stylus inspection and, based on those findings, proposes a cost-effective microscopy approach. The operational principle is then demonstrated by an automated prototype, coordinated directly by the CMM software MCOSMOS, with an effective threshold of detection as low as 400 nm and a large field of view and depth of field. The level of contamination on the stylus has been found to increase steadily with the number of measurement contacts made. Once excessive contamination is detected on the stylus, measurement should be stopped and a stylus cleaning procedure should be performed to avoid affecting measurement accuracy. (paper)

  19. Measurement of iron absorption from meals contaminated with iron

    International Nuclear Information System (INIS)

    Hallberg, L.; Bjoern-Rasmussen, E.

    1981-01-01

    A method is described to measure in vitro the extent of isotopic exchange between the native nonheme food iron and added inorganic reduction to radioiron tracer. The food is digested with pepsin and trypsin in the presence of radioiron. The exchangeability of food iron is calculated from the specific activity in the food and in an extract of bathophenantroline in isoamyl alcohol obtained after digesting this food. The precision and accuracy of the method is illustrated by two kinds of studies, those in which different amounts of contamination iron are added to a meal and those evaluating contamination iron in natural meals. The present method will make it possible to measure validly iron absorption from meals contaminated with unknown amounts of iron of unknown exchangeability with the extrinsic radioiron tracer

  20. Unbiased contaminant removal for 3D galaxy power spectrum measurements

    Science.gov (United States)

    Kalus, B.; Percival, W. J.; Bacon, D. J.; Samushia, L.

    2016-11-01

    We assess and develop techniques to remove contaminants when calculating the 3D galaxy power spectrum. We separate the process into three separate stages: (I) removing the contaminant signal, (II) estimating the uncontaminated cosmological power spectrum and (III) debiasing the resulting estimates. For (I), we show that removing the best-fitting contaminant (mode subtraction) and setting the contaminated components of the covariance to be infinite (mode deprojection) are mathematically equivalent. For (II), performing a quadratic maximum likelihood (QML) estimate after mode deprojection gives an optimal unbiased solution, although it requires the manipulation of large N_mode^2 matrices (Nmode being the total number of modes), which is unfeasible for recent 3D galaxy surveys. Measuring a binned average of the modes for (II) as proposed by Feldman, Kaiser & Peacock (FKP) is faster and simpler, but is sub-optimal and gives rise to a biased solution. We present a method to debias the resulting FKP measurements that does not require any large matrix calculations. We argue that the sub-optimality of the FKP estimator compared with the QML estimator, caused by contaminants, is less severe than that commonly ignored due to the survey window.

  1. A simplified ALARA approach to demonstration of compliance with surface contaminated object regulatory requirements

    International Nuclear Information System (INIS)

    Pope, R.B.; Shappert, L.B.; Michelhaugh, R.D.; Boyle, R.W.; Cook, J.C.

    1998-02-01

    The US Department of Transportation (DOT) and the US Nuclear Regulatory Commission (NRC) have jointly prepared a comprehensive set of draft guidance for consignors and inspectors to use when applying the newly imposed regulatory requirements for low specific activity (LSA) material and surface contaminated objects (SCOs). The guidance is being developed to facilitate compliance with the new LSA material and SCO requirements, not to impose additional requirements. These new requirements represent, in some areas, significant departures from the manner in which packaging and transportation of these materials and objects were previously controlled. On occasion, it may be appropriate to use conservative approaches to demonstrate compliance with some of the requirements, ensuring that personnel are not exposed to radiation at unnecessary levels, so that exposures are kept as low as reasonably achievable (ALARA). In the draft guidance, one such approach would assist consignors preparing a shipment of a large number of SCOs in demonstrating compliance without unnecessarily exposing personnel. In applying this approach, users need to demonstrate that four conditions are met. These four conditions are used to categorize non-activated, contaminated objects as SCO-2. It is expected that, by applying this approach, it will be possible to categorize a large number of small contaminated objects as SCO-2 without the need for detailed, quantitative measurements of fixed, accessible contamination, or of total (fixed and non-fixed) contamination on inaccessible surfaces. The method, which is based upon reasoned argument coupled with limited measurements and the application of a sum of fractions rule, is described and examples of its use are provided

  2. Cross-contamination in the kitchen: effect of hygiene measures

    NARCIS (Netherlands)

    Jong, de A.E.I.; Verhoeff-Bakkenes, L.; Nauta, M.J.; Jonge, de R.

    2008-01-01

    Aims: To determine the effect of hygiene measures on cross-contamination of Campylobacter jejuni at home and to select a safe tracer organism for C. jejuni. Methods and Results: Comparative tests were conducted with nonpathogenic Escherichia coli and Lactobacillus casei and L. casei was chosen as

  3. Techniques for the measurement of the contamination of air

    International Nuclear Information System (INIS)

    Labeyrie, J.

    1960-01-01

    This lecture has been given at the International Symposium of Riso 1959. Methods for measuring radioactive content of the atmosphere are described, and main results found at Saclay are given, for the following contaminants: Rn, Tn and their daughter, H-3, C-14, A-41, Kr-85, I-131, and fission products as a whole. (author) [fr

  4. Molecular-level removal of proteinaceous contamination from model surfaces and biomedical device materials by air plasma treatment.

    Science.gov (United States)

    Banerjee, K K; Kumar, S; Bremmell, K E; Griesser, H J

    2010-11-01

    Established methods for cleaning and sterilising biomedical devices may achieve removal of bioburden only at the macroscopic level while leaving behind molecular levels of contamination (mainly proteinaceous). This is of particular concern if the residue might contain prions. We investigated at the molecular level the removal of model and real-life proteinaceous contamination from model and practical surfaces by air plasma (ionised air) treatment. The surface-sensitive technique of X-ray photoelectron spectroscopy (XPS) was used to assess the removal of proteinaceous contamination, with the nitrogen (N1s) photoelectron signal as its marker. Model proteinaceous contamination (bovine serum albumin) adsorbed on to a model surface (silicon wafer) and the residual proteinaceous contamination resulting from incubating surgical stainless steel (a practical biomaterial) in whole human blood exhibited strong N1s signals [16.8 and 18.5 atomic percent (at.%), respectively] after thorough washing. After 5min air plasma treatment, XPS detected no nitrogen on the sample surfaces, indicating complete removal of proteinaceous contamination, down to the estimated XPS detection limit 10ng/cm(2). Applying the same plasma treatment, the 7.7at.% nitrogen observed on a clinically cleaned dental bur was reduced to a level reflective of new, as-received burs. Contact angle measurements and atomic force microscopy also indicated complete molecular-level removal of the proteinaceous contamination upon air plasma treatment. This study demonstrates the effectiveness of air plasma treatment for removing proteinaceous contamination from both model and practical surfaces and offers a method for ensuring that no molecular residual contamination such as prions is transferred upon re-use of surgical and dental instruments. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  5. Trench 'bathtubbing' and surface plutonium contamination at a legacy radioactive waste site.

    Science.gov (United States)

    Payne, Timothy E; Harrison, Jennifer J; Hughes, Catherine E; Johansen, Mathew P; Thiruvoth, Sangeeth; Wilsher, Kerry L; Cendón, Dioni I; Hankin, Stuart I; Rowling, Brett; Zawadzki, Atun

    2013-01-01

    Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (~12 Bq/L of (239+240)Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest (239+240)Pu soil activity was 829 Bq/kg in a shallow sample (0-1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the 'bathtub' effect.

  6. Trench ‘Bathtubbing’ and Surface Plutonium Contamination at a Legacy Radioactive Waste Site

    Science.gov (United States)

    2013-01-01

    Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (∼12 Bq/L of 239+240Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest 239+240Pu soil activity was 829 Bq/kg in a shallow sample (0–1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the ‘bathtub’ effect. PMID:24256473

  7. Proposal of traceability chain for direct measurements of radioactive contamination in Cuba

    International Nuclear Information System (INIS)

    Walwyn Salas, Gonzalo; Tamayo Garcia, Jose A.; Cornejo Diaz, Nestor

    2008-01-01

    The measurements of the radioactive surface contamination are common used to demonstrate the compliance with safety regulations at national level. It is mandatory that those measurements are traceable to national standards through the suitable calibration of the monitors used for survey. In Cuba, there is not a harmonized methodology for evaluation of contamination from direct measurements and no standardized calibration service for portable monitors is routinely provided to users. The Secondary Standard Dosimetry Laboratory of Cuba has recently established the calibration service of contamination monitors in terms of instrument efficiency using the reference sources of known emission rate per unit area in accordance with international normative ISO 8769. In the present paper, is proposed a traceable scheme of direct measurements of contamination that involve the calibration at the laboratory level using multi-source method and the evaluation of contaminations at user level in terms of activity per unit area. Some improvements from the previous single-source method of calibration are explained in order to support the advantages that offer the new chain for those measurements in the country. (author)

  8. Surface deposition measurements of the TMI-2 gross decontamination experiment

    International Nuclear Information System (INIS)

    McIssac, C.V.; Hetzer, D.C.

    1982-01-01

    In order to measure the effectiveness of the gross decontamination experiment (principally a water spray technique) performed in the TMI-2 reactor building, the Technical Information and Examination Program's Radiation and Environment personnel made surface activity measurements before and after the experiment. In conjunction with surface sampling, thermoluminescent dosimeter (TLD) and gamma spectrometry measurements were also performed to distinguish between radiation fields and contamination. The surface sampler used to collect samples from external surfaces within the reactor building is a milling tool having four major components: a 1.27-cm constant-speed drill; a drill support assembly that allows setting sample penetration depth; filter cartridges for intake air purification and sample collection; and an air pump that forces air across the surface being sampled and through the sample filter cartridge

  9. Bioremediation of contaminated surface water by immobilized Micrococcus roseus.

    Science.gov (United States)

    Li, H; Li, P; Hua, T; Zhang, Y; Xiong, X; Gong, Z

    2005-08-01

    The problems caused by contaminated surface water have gradually become more serious in recent years. Although various remediation technologies were investigated, unfortunately, no efficient method was developed. In this paper, a new bioremediation technology was studied using Micrococcus roseus, which was immobilized in porous spherical beads by an improved polyvinyl alcohol (PVA) - sodium alginate (SA) embedding method. The experimental results indicated that COD removal rate could reach 64.7 % within 72 hours when immobilized M. roseus beads were used, which was ten times as high as that of free cells. The optimum inoculation rate of immobilized M. roseus beads was 10 % (mass percent of the beads in water sample, g g(-1)). Suitable aeration was proved necessary to enhance the bioremediation process. The immobilized cells had an excellent tolerance to pH and temperature changes, and were also more resistant to heavy metal stress compared with free cells. The immobilized M. roseus beads had an excellent regeneration capacity and could be reused after 180-day continuous usage. The Scanning Electronic Microscope (SEM) analysis showed that the bead microstructure was suitable for M. roseus growth, however, some defect structures should still be improved.

  10. The measurement of surface gravity.

    Science.gov (United States)

    Crossley, David; Hinderer, Jacques; Riccardi, Umberto

    2013-04-01

    This review covers basic theory and techniques behind the use of ground-based gravimetry at the Earth's surface. The orientation is toward modern instrumentation, data processing and interpretation for observing surface, land-based, time-variable changes to the geopotential. The instrumentation side is covered in some detail, with specifications and performance of the most widely used models of the three main types: the absolute gravimeters (FG5, A10 from Micro-g LaCoste), superconducting gravimeters (OSG, iGrav from GWR instruments), and the new generation of spring instruments (Micro-g LaCoste gPhone, Scintrex CG5 and Burris ZLS). A wide range of applications is covered, with selected examples from tides and ocean loading, atmospheric effects on gravity, local and global hydrology, seismology and normal modes, long period and tectonics, volcanology, exploration gravimetry, and some examples of gravimetry connected to fundamental physics. We show that there are only a modest number of very large signals, i.e. hundreds of µGal (10(-8) m s(-2)), that are easy to see with all gravimeters (e.g. tides, volcanic eruptions, large earthquakes, seasonal hydrology). The majority of signals of interest are in the range 0.1-5.0 µGal and occur at a wide range of time scales (minutes to years) and spatial extent (a few meters to global). Here the competing effects require a careful combination of different gravimeter types and measurement strategies to efficiently characterize and distinguish the signals. Gravimeters are sophisticated instruments, with substantial up-front costs, and they place demands on the operators to maximize the results. Nevertheless their performance characteristics such as drift and precision have improved dramatically in recent years, and their data recording ability and ruggedness have seen similar advances. Many subtle signals are now routinely connected with known geophysical effects such as coseismic earthquake displacements, post

  11. Measuring techniques for the characterisation of 137Cs contaminated river banks, Slovakia

    International Nuclear Information System (INIS)

    Slavik, O.; Moravek, J.

    2000-01-01

    In 1990, 137 Cs contaminated areas were discovered along 19 km of the banks of the rivers receiving discharged waste waters from the Bohunice NPP. The contamination was the result of uncontrolled releases of drainage water from the radioactive waste treatment unit and two accidents on the CO 2 cooled and heavy water moderated NPP-A1 unit in 1976 and 1977. In total, more than 67.000 m 2 of bank surfaces (the lower and middle parts of their slopes) have been found to be contaminated with 137 Cs at levels exceeding 1 kBq/kg of soil. This paper describes the planning for restoration of these river banks with emphasis on site characterization techniques used for these purposes. The general strategy and application of monitoring techniques for the purposes of characterisation of contaminated river banks is the main topic of the work performed in the context of the IAEA CRP on 'Site Characterisation Techniques for Environmental Restoration'. First results in developing new and more sophisticated measuring techniques, needed for the characterization of discontinuous and spot-contamination found on parts of the banks are given. The technique described is based on a dose rate measurement approach, using ratio of two detector readings at two different distances above ground and Monte-Carlo simulations of the plastic scintillation detector responses. The method will also be useful, for the final, post-remediation survey of residual spots of 137 Cs contamination. (author)

  12. Measures to be taken in cases of radioactive contamination of the skin

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This recommendation refers to those technical, medical and scientific facilities in which unsealed radioactive substances are handled. These facilities include, among other things: nuclear power plants, facilities of the fuel cycle, scientific and industrial laboratories, doctors' practices, hospitals and medical laboratories. Any unnecessary contamination of individuals shall be avoided. If contamination does occur, the resulting radiation exposure shall be kept as low as possible, even below the dose limits of the Radiological Protection Ordinance, taking into consideration the state of the art and also taking into account all circumstances pertaining to each individual case. Preventive measures to avoid or limit contamination represent the most effective form of protection. Preventive measures therefore include regular checks on the condition of the skin and constant personal skin care. Specific decontamination instructions must be provided for each individual plant and also, where applicable, for each individual workplace. Contaminated items of clothing must be removed before decontamination is commenced. Low levels of contamination can usually be eleminated in one step by washing with water. There is no need to carry out further decontamination steps where the decontamination effect is less than 10% and the remaining surface-related activity is less than 10 Bq/cm 2 (averaged over 100 cm 2 where the contamination is largely distributed over the entire area). (orig.) [de

  13. FJ-2207 measuring instrument detection pipe surface a level of pollution method

    International Nuclear Information System (INIS)

    Wang Jiangong

    2010-01-01

    On the pipe surface contamination were detected α level of pollution is a frequently encountered dose-detection work. Because the pipeline surface arc, while the measuring probe for the plane, which for accurate measurement difficult. In this paper, on the FJ-2207-type pipe surface contamination measuring instrument measuring pollution levels in the α method was studied. Introduced the FJ-2207 measuring instrument detection pipe surface α pollution levels. Studied this measuring instrument on the same sources of surface, plane α level of radioactivity measured differences in the results obtained control of the apparatus when the direct measurement of the surface correction factor, and gives 32-216 specifications commonly used pipe direct measurement of the amendment factor. Convenient method, test results are reliable for the accurate measurement of pipe pollution levels in the surface of α as a reference and learning. (authors)

  14. HTO transfer from contaminated surfaces to the atmosphere: a database for model validation

    International Nuclear Information System (INIS)

    Davis, P.A.; Amiro, B.D.; Workman, W.J.G.; Corbett, B.J.

    1996-12-01

    This report comprises a detailed database that can be used to validate models of the emission of tritiated water vapour (HTO) from natural contaminated surfaces to the atmosphere. The data were collected in 1992 July during an intensive field study based on the flux-gradient method of micrometeorology. The measurements were made over a wetland area at the Chalk River Laboratories, and over a grassed field near the Pickering Nuclear Generating Station. The study sites, the sampling protocols and the analytical techniques are described in detail, and the measured fluxes are presented. The report also contains a detailed listing of HTO concentrations in air at two heights, HTO concentrations in the source compartments (soil, surface water and vegetation), supporting meteorological data, and various vegetation and soil properties. The uncertainties in all of the measured data are estimated. (author). 15 refs., 23 tabs., 9 figs

  15. Assessment of Surface Water Contamination from Coalbed Methane Fracturing-Derived Volatile Contaminants in Sullivan County, Indiana, USA.

    Science.gov (United States)

    Meszaros, Nicholas; Subedi, Bikram; Stamets, Tristan; Shifa, Naima

    2017-09-01

    There is a growing concern over the contamination of surface water and the associated environmental and public health consequences from the recent proliferation of hydraulic fracturing in the USA. Petroleum hydrocarbon-derived contaminants of concern [benzene, toluene, ethylbenzene, and xylenes (BTEX)] and various dissolved cations and anions were spatially determined in surface waters around 15 coalbed methane fracking wells in Sullivan County, IN, USA. At least one BTEX compound was detected in 69% of sampling sites (n = 13) and 23% of sampling sites were found to be contaminated with all of the BTEX compounds. Toluene was the most common BTEX compound detected across all sampling sites, both upstream and downstream from coalbed methane fracking wells. The average concentration of toluene at a reservoir and its outlet nearby the fracking wells was ~2× higher than other downstream sites. However, one of the upstream sites was found to be contaminated with BTEX at similar concentrations as in a reservoir site nearby the fracking well. Calcium (~60 ppm) and sulfates (~175 ppm) were the dominant cations and anions, respectively, in surface water around the fracking sites. This study represents the first report of BTEX contamination in surface water from coalbed methane hydraulic fracturing wells.

  16. Contribution of the surface contamination of uranium-materials on the quantitative analysis results by electron probe microbeam analysis

    International Nuclear Information System (INIS)

    Bonino, O.; Fournier, C.; Fucili, C.; Dugne, O.; Merlet, C.

    2000-01-01

    The analytical testing of uranium materials is necessary for quality research and development in nuclear industry applications (enrichment, safety studies, fuel, etc). Electron Probe Microbeam Analysis Wavelength Dispersive Spectrometry (EPMA-WDS) is a dependable non-destructive analytical technology. The characteristic X-ray signal is measured to identify and quantify the sample components, and the analyzed volume is about one micron cube. The surface contamination of uranium materials modifies and contributes to the quantitative analysis results of EPMA-WDS. This contribution is not representative of the bulk. A thin oxidized layer appears in the first instants after preparation (burnishing, cleaning) as well as a carbon contamination layer, due to metallographic preparation and carbon cracking under the impact of the electron probe. Several analytical difficulties subsequently arise, including an overlapping line between the carbon Ka ray and the Uranium U NIVOVI ray. Sensitivity and accuracy of the quantification of light elements like carbon and oxygen are also reduced by the presence of uranium. The aim of this study was to improve the accuracy of quantitative analysis on uranium materials by EPMA-WDS by taking account of the contribution of surface contamination. The first part of this paper is devoted to the study of the contaminated surface of the uranium materials U, UFe 2 and U 6 Fe a few hours after preparation. These oxidation conditions are selected so as to reproduce the same contamination surfaces occurring in microprobe analytical conditions. Surface characterization techniques were SIMS and Auger spectroscopy. The contaminated surfaces are shown. They consist of successive layers: a carbon layer, an oxidized iron layer, followed by an iron depletion layer (only in UFe 2 and U 6 Fe), and a ternary oxide layer (U-Fe-O for UFe 2 et U 6 Fe and UO 2+x for uranium). The second part of the paper addresses the estimation of the errors in quantitative

  17. 10 CFR Appendix D to Part 835 - Surface Contamination Values

    Science.gov (United States)

    2010-01-01

    ... posting of contamination and high contamination areas in accordance with § 835.603(e) and (f) and...-228, Th-230, Th-228, Pa-231, Ac-227, I-125, I-129 20 500 Th-nat, Th-232, Sr-90, Ra-223, Ra-224, U-232... pressure, and then assessing the amount of radioactive material on the swipe with an appropriate instrument...

  18. Characterization of surface water contaminants in the Clinch River and Poplar Creek

    International Nuclear Information System (INIS)

    Ford, C.; Madix, S.; Rash, C.

    1995-01-01

    Surface waters in the Clinch River and Poplar Creek have been contaminated by activities on the DOE's Oak Ridge Reservation throughout the more than 50 year history of Oak Ridge. Though the Clinch River and Poplar Creek drainage areas are contaminated with heavy metals, organics and radionuclides, public access to these sites is not restricted. The investigation, divided into discrete studies, was tailored to provide a statistically sound picture of contaminants and aqueous toxicity in Poplar Creek, investigate contaminant remobilization from sediments, and determine contaminant levels during a series of ''worst-case'' events. Results for Poplar Creek indicate that average contaminant values were below levels of concern for human health and ecological risk, though contaminant distributions suggest that episodic events contribute sufficiently to system contaminant levels to be of concern. Additionally, water column contaminant levels were significantly higher in particle deposition areas rather than at known contaminant sources. Levels of organic compounds in reference areas to Poplar Creek exceeded those in the Poplar Creek study area. In the Clinch River and Poplar Creek, statistical differences in metal and radionuclide levels from known contaminated areas confirmed previous results, and were used to independently distinguish between sites. Contaminant concentrations were elevated in association with sediments, though no distinction between deposition and remobilization could be made. Due to elevated contaminant levels, and some unexpected contaminant distributions, sites in Poplar Creek and off-channel embayments of the Clinch River were identified that will require additional characterization

  19. Materials SIG quantification and characterization of surface contaminants

    Science.gov (United States)

    Crutcher, E. Russ

    1992-01-01

    When LDEF entered orbit its cleanliness was approximately a MIL-STD-1246B Level 2000C. Its burden of contaminants included particles from every part of its history including a relatively small contribution from the shuttle bay itself. Although this satellite was far from what is normally considered clean in the aerospace industry, contaminating events in orbit and from processing after recovery were easily detected. The molecular contaminants carried into orbit were dwarfed by the heavy deposition of UV polymerized films from outgassing urethane paints and silicone based materials. Impacts by relatively small objects in orbit could create particulate contaminants that easily dominated the particle counts within a centimeter of the impact site. During the recovery activities LDEF was 'sprayed' with a liquid high in organics and water soluble salts. With reentry turbulence, vibration, and gravitational loading particulate contaminants were redistributed about LDEF and the shuttle bay.

  20. Radioactive contamination of some rubber or plastic surfaces by fission products. Decontamination tests

    International Nuclear Information System (INIS)

    Mestre, E.; Sautiez, N.

    1957-10-01

    With the objective of notably addressing the contamination and decontamination of gloves and floor covering, this report first presents some characteristics of contaminating radioactive materials (nature, physical and chemical condition), of contaminated surfaces (surface condition, surface nature), and of decontamination processes (physical, chemical or mechanical action). It describes the operational modality implemented to test decontamination processes on various glove or flooring materials: sample preparation, counting, decontamination, reproducibility of decontamination tests, results in terms of activity reduction. It more precisely describes the tested samples: short gloves, gloves from glove boxes, floor and wall coverings. Results are presented and discussed in terms of sample susceptibility to contamination, and of decontamination, but also for re-contamination tests after a Nab-based decontamination (susceptibility to contamination, decontamination gain)

  1. Direct-scanning alpha spectrometer for americium and plutonium contamination on highly-enriched uranium surfaces

    International Nuclear Information System (INIS)

    Ward, W.C.; Martinez, H.E.; Abeyta, C.L.; Morgan, A.N.; Nelson, T.O.

    1997-01-01

    Trace Pu 239 and Am 241 contamination on a surface whose alpha count is dominated by U 235 and U 234 decay has been successfully quantified by counting swipes in external alpha spectroscopy chambers. The swipe process, however, is labor intensive and subject to uncertainties in the swiping process as well as degraded spectral resolution due to the presence of the swipe material. A multichannel instrument for automated in situ measurements of interior and exterior contamination has been developed which incorporates a rotary table, 13 fixed ion-implanted silicon detectors, and spectroscopy electronics. Custom software was written to allow alpha spectrometer to function as a virtual instrument in the LabView environment. This system gives improved speed and resolution as well as a complete log of the location of areas of high surface contamination, a feature not practical to obtain by other methods, and one which opens the possibility of long term studies such as Pu outgrowth evaluation employing the instrument. The authors present performance data as well as system integration, calibration, control, and dynamic geometric efficiency calculations related to the design of this and next generation systems

  2. Assessment of surface contamination level in an operating uranium ore processing facility of Jaduguda, India

    International Nuclear Information System (INIS)

    Meena, J.S.; Patnaik, R.L.; Jha, V.N.; Sahoo, S.K.; Ravi, P.M.; Tripathi, R.M.

    2014-01-01

    Radiological concern of the occupational workers and the area is given priority over other safety issue in confirmation with the stipulated guideline of national regulatory agency (AERB/FEFCF/SG-2, 2007). The key concern from the radiological hazard evaluation point of view is air activity, external gamma level and surface contamination. Present investigations was carried out to ascertain the surface contamination level of uranium ore processing facility at Jaduguda, Jharkhand. For a low grade uranium ore processing industry surface contamination is a major concern in product precipitation and recovery section. In view of this, the ore processing plant can broadly be classified into three areas i.e. ion exchange area, precipitation and product recovery section and other areas. The monitoring results incorporate the level of surface contamination of the plant during the last five years. The geometric mean activity of surface contamination level was 31.1, 34.5 and 9.8 Bq dm -2 in ion exchange, product precipitation and recovery and other areas with GSD of 2, 2.5 and 1.9. In most of the cases the surface contamination level was well within the recommended limit of 100 Bq dm -2 for M class uranium compound. Occasional cases of surface contamination levels exceeding the recommended limit were addressed and areas were decontaminated. Based on the study, modification in the design feature of the surface of the finished product section was also suggested so that the decontamination procedure can be more effectively implemented

  3. Decontamination of plutonium-contaminated surfaces; Essais de decontamination des surfaces contaminees par du plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, J; Clouet d' Orval, Ch; Tachon, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The measure of the neutron distribution in the core of 'Proserpine', by means of activation detectors, requires no contact between the plutonium sulfate solution and the detectors. These detectors are put into PVC or polyethylene bags. This report describes the process used to decontaminate these bags. A washing by nitric acid followed by coating with plexiglass is kept, with this process we have no contamination on the detectors. (author) [French] La mesure de la distribution de neutrons par detecteurs a activation dans le coeur de Proserpine exige de proteger ces detecteurs contre tout contact avec la solution de plutonium. Les detecteurs sont places dans des gaines en polyvinyle ou en polyethylene. Ce rapport decrit le procede utilise pour decontaminer ces gaines. On a retenu un lavage a l'acide nitrique suivi du revetement d'une meme couche de plexiglass, ce qui permet d'eviter la contamination des detecteurs. (auteur)

  4. Surface soil contamination standards for Rockwell Hanford Operations

    International Nuclear Information System (INIS)

    Boothe, G.F.

    1981-01-01

    The 200 Areas of the Hanford site contain soils contaminated with levels of radioactivity ranging from fallout concentrations to levels requiring radiological controls. Some contamination is more or less uniformly distributed, and some occurs as discrete specks or spots of activity. Because of the acute need for standards, the Rockwell Environmental Protection (EP) Group proceeded to develop standards; these were approved by Rockwell in October 1979. It must be emphasized that these standards are only applicable to the 200 Areas of the Hanford site or other areas under Rockwell's jurisdiction. It is assumed that access to these areas will always be restricted and that land-use restrictions will be maintained. Contamination limits for areas used by the general public would normally be lower than the limits derived in this case. It appears that the Rockwell standards divided by a factor of 5 to 10 may be reasonable contamination guidelines for the general environment

  5. Estimation of the amount of surface contamination of a water cooled nuclear reactor by cooling water analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, G. [KFKI Atomic Energy Research Institute, P.O. Box 49, Budapest H-1525 (Hungary)]. E-mail: nagyg@sunserv.kfki.hu; Somogyi, A. [KFKI Atomic Energy Research Institute, P.O. Box 49, Budapest H-1525 (Hungary); Patek, G. [Paks Nuclear Power Plant, P.O. Box 71, Paks H-7031 (Hungary); Pinter, T. [Paks Nuclear Power Plant, P.O. Box 71, Paks H-7031 (Hungary); Schiller, R. [KFKI Atomic Energy Research Institute, P.O. Box 49, Budapest H-1525 (Hungary)

    2007-06-15

    Calculations, based upon on-the-spot measurements, were performed to estimate the contamination of NPP primary circuit and spent fuel storage pool solid surfaces via the composition of the cooling water in connection with a non-nuclear incident in the Paks NPP. Thirty partially burnt-up fuel element bundles were damaged during a cleaning process, an incident which resulted in the presence of fission products in the cooling water of the cleaning tank (CT) situated in a separate pool (P1). Since this medium was in contact for an extended period of time with undamaged fuel elements to be used later and also with other structural materials of the spent fuel storage pool (SP), it was imperative to assess the surface contamination of these latter ones with a particular view to the amount of fission material. In want of direct methods, one was restricted to indirect information which rested mainly on the chemical and radiochemical data of the cooling water. It was found that (i) the most important contaminants were uranium, plutonium, cesium and cerium; (ii) after the isolation of P1 and SP and an extended period of filtering the only important contaminants were uranium and plutonium; (iii) the surface contamination of the primary circuit (PC) was much lower than that of either SP or P1; (iv) some 99% of the contamination was removed from the water by the end of the filtering process.

  6. Thallium dispersal and contamination in surface sediments from South China and its source identification.

    Science.gov (United States)

    Liu, Juan; Wang, Jin; Chen, Yongheng; Shen, Chuan-Chou; Jiang, Xiuyang; Xie, Xiaofan; Chen, Diyun; Lippold, Holger; Wang, Chunlin

    2016-06-01

    Thallium (Tl) is a non-essential element in humans and it is considered to be highly toxic. In this study, the contents, sources, and dispersal of Tl were investigated in surface sediments from a riverine system (the western Pearl River Basin, China), whose catchment has been contaminated by mining and roasting of Tl-bearing pyrite ores. The isotopic composition of Pb and total contents of Tl and other relevant metals (Pb, Zn, Cd, Co, and Ni) were measured in the pyrite ores, mining and roasting wastes, and the river sediments. Widespread contamination of Tl was observed in the sediments across the river, with the highest concentration of Tl (17.3 mg/kg) measured 4 km downstream from the pyrite industrial site. Application of a modified Institute for Reference Materials and Measurement (IRMM) sequential extraction scheme in representative sediments unveiled that 60-90% of Tl and Pb were present in the residual fraction of the sediments. The sediments contained generally lower (206)Pb/(207)Pb and higher (208)Pb/(206)Pb ratios compared with the natural Pb isotope signature (1.2008 and 2.0766 for (206)Pb/(207)Pb and (208)Pb/(206)Pb, respectively). These results suggested that a significant fraction of non-indigenous Pb could be attributed to the mining and roasting activities of pyrite ores, with low (206)Pb/(207)Pb (1.1539) and high (208)Pb/(206)Pb (2.1263). Results also showed that approximately 6-88% of Tl contamination in the sediments originated from the pyrite mining and roasting activities. This study highlights that Pb isotopic compositions could be used for quantitatively fingerprinting the sources of Tl contamination in sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Evaluation of wastewater contaminant transport in surface waters using verified Lagrangian sampling

    Science.gov (United States)

    Antweiler, Ronald C.; Writer, Jeffrey H.; Murphy, Sheila F.

    2014-01-01

    Contaminants released from wastewater treatment plants can persist in surface waters for substantial distances. Much research has gone into evaluating the fate and transport of these contaminants, but this work has often assumed constant flow from wastewater treatment plants. However, effluent discharge commonly varies widely over a 24-hour period, and this variation controls contaminant loading and can profoundly influence interpretations of environmental data. We show that methodologies relying on the normalization of downstream data to conservative elements can give spurious results, and should not be used unless it can be verified that the same parcel of water was sampled. Lagrangian sampling, which in theory samples the same water parcel as it moves downstream (the Lagrangian parcel), links hydrologic and chemical transformation processes so that the in-stream fate of wastewater contaminants can be quantitatively evaluated. However, precise Lagrangian sampling is difficult, and small deviations – such as missing the Lagrangian parcel by less than 1 h – can cause large differences in measured concentrations of all dissolved compounds at downstream sites, leading to erroneous conclusions regarding in-stream processes controlling the fate and transport of wastewater contaminants. Therefore, we have developed a method termed “verified Lagrangian” sampling, which can be used to determine if the Lagrangian parcel was actually sampled, and if it was not, a means for correcting the data to reflect the concentrations which would have been obtained had the Lagrangian parcel been sampled. To apply the method, it is necessary to have concentration data for a number of conservative constituents from the upstream, effluent, and downstream sites, along with upstream and effluent concentrations that are constant over the short-term (typically 2–4 h). These corrections can subsequently be applied to all data, including non-conservative constituents. Finally, we

  8. Evaluation of wastewater contaminant transport in surface waters using verified Lagrangian sampling.

    Science.gov (United States)

    Antweiler, Ronald C; Writer, Jeffrey H; Murphy, Sheila F

    2014-02-01

    Contaminants released from wastewater treatment plants can persist in surface waters for substantial distances. Much research has gone into evaluating the fate and transport of these contaminants, but this work has often assumed constant flow from wastewater treatment plants. However, effluent discharge commonly varies widely over a 24-hour period, and this variation controls contaminant loading and can profoundly influence interpretations of environmental data. We show that methodologies relying on the normalization of downstream data to conservative elements can give spurious results, and should not be used unless it can be verified that the same parcel of water was sampled. Lagrangian sampling, which in theory samples the same water parcel as it moves downstream (the Lagrangian parcel), links hydrologic and chemical transformation processes so that the in-stream fate of wastewater contaminants can be quantitatively evaluated. However, precise Lagrangian sampling is difficult, and small deviations - such as missing the Lagrangian parcel by less than 1h - can cause large differences in measured concentrations of all dissolved compounds at downstream sites, leading to erroneous conclusions regarding in-stream processes controlling the fate and transport of wastewater contaminants. Therefore, we have developed a method termed "verified Lagrangian" sampling, which can be used to determine if the Lagrangian parcel was actually sampled, and if it was not, a means for correcting the data to reflect the concentrations which would have been obtained had the Lagrangian parcel been sampled. To apply the method, it is necessary to have concentration data for a number of conservative constituents from the upstream, effluent, and downstream sites, along with upstream and effluent concentrations that are constant over the short-term (typically 2-4h). These corrections can subsequently be applied to all data, including non-conservative constituents. Finally, we show how data

  9. Visible-light system for detecting doxorubicin contamination on skin and surfaces.

    Science.gov (United States)

    Van Raalte, J; Rice, C; Moss, C E

    1990-05-01

    A portable system that uses fluorescence stimulated by visible light to identify doxorubicin contamination on skin and surfaces was studied. When activated by violet-blue light in the 465-nm range, doxorubicin fluoresces, emitting orange-red light in the 580-nm range. The light source to stimulate fluorescence was a slide projector with a filter to selectively pass short-wave (blue) visible light. Fluorescence was both observed visually with viewing spectacles and photographed. Solutions of doxorubicin in sterile 0.9% sodium chloride injection were prepared in nine standard concentrations ranging from 2 to 0.001 mg/mL. Droplets of each admixture were placed on stainless steel, laboratory coat cloth, pieces of latex examination glove, bench-top absorbent padding, and other materials on which antineoplastics might spill or leak. These materials then were stored for up to eight weeks and photographed weekly. The relative ability of water, household bleach, hydrogen peroxide solution, and soap solution to deactivate doxorubicin was also measured. Finally, this system was used to inspect the antineoplastic-drug preparation and administration areas of three outpatient cancer clinics for doxorubicin contamination. Doxorubicin fluorescence was easily detectable with viewing spectacles when a slide projector was used as the light source. The photographic method was sensitive for doxorubicin concentrations from 2.0 to 0.001 mg/mL. Immersion of study materials in bleach for one minute eliminated detectable fluorescence. Doxorubicin contamination is detectable for at least eight weeks in the ambient environment. Probable doxorubicin contamination was detected in two of the three clinics surveyed. A safe, portable system that uses fluorescence stimulated by visible light is a sensitive method for detecting doxorubicin on skin and surfaces.

  10. Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff.

    Science.gov (United States)

    Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Cahn, Michael

    2017-05-15

    Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

  11. Contaminant interferences with SIMS analyses of microparticle impactor residues on LDEF surfaces

    International Nuclear Information System (INIS)

    Simon, C.G.; Batchelor, D.; Griffis, D.P.; Hunter, J.L.; Misra, V.; Ricks, D.A.; Wortman, J.J.

    1992-01-01

    Elemental analyses of impactor residues on high purity surface exposed to the low earth orbit (LEO) environment for 5.8 years on Long Duration Exposure Facility (LDEF) has revealed several probable sources for microparticles at this altitude, including natural micrometeorites and manmade debris ranging from paint pigments to bits of stainless steel. A myriad of contamination interferences were identified and their effects on impactor debris identification mitigated during the course of this study. These interferences included pre-, post-, and in-flight deposited particulate surface contaminants, as well as indigenous heterogeneous material contaminants. Non-flight contaminants traced to human origins, including spittle and skin oils, contributed significant levels of alkali-rich carbonaceous interferences. A ubiquitous layer of in-flight deposited silicaceous contamination varied in thickness with location on LDEF and proximity to active electrical fields. In-flight deposited (low velocity) contaminants included urine droplets and bits of metal film from eroded thermal blankets

  12. Concrete decontamination: two innovative processes in response to surface or deep contamination

    International Nuclear Information System (INIS)

    CUER, F.; Nadai, A. de; Faure, S.

    2008-01-01

    To meet the future needs in the nuclear industry as regards dismantling and decommissioning, the LPAD (Laboratoire des Procedes Avances de Decontamination) develops new specific techniques to decontaminate concretes: the drying gel process adapted to surface contamination and the electrokinetics process to treat deep contamination. Indeed, because the concrete constitute a porous medium, two types of contamination can be met according to the environment to which is subjected the material. In the case of an accidental or dry contamination, radio elements do not penetrate beyond the first millimeters of the material. The contamination is then considered as surface. On the contrary, the contamination is considered as 'deep' when radioactive ions have diffused deeply under the effects of the natural diffusion. This is the case in fuel storage pond or other many nuclear infrastructures. (authors)

  13. Removal of carbon contaminations by RF plasma generated reactive species and subsequent effects on optical surface

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, P. K., E-mail: praveenyadav@rrcat.gov.in; Rai, S. K.; Modi, M. H.; Nayak, M.; Lodha, G. S. [Indus Synchrotron Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Kumar, M.; Chakera, J. A.; Naik, P. A. [Laser Plasma Laboratory, Laser Plasma Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India)

    2015-06-24

    Carbon contamination on optical elements is a serious issue in synchrotron beam lines for several decades. The basic mechanism of carbon deposition on optics and cleaning strategies are not fully understood. Carbon growth mechanism and optimized cleaning procedures are worldwide under development stage. Optimized RF plasma cleaning is considered an active remedy for the same. In present study carbon contaminated optical test surfaces (carbon capped tungsten thin film) are exposed for 30 minutes to four different gases, rf plasma at constant power and constant dynamic pressure. Structural characterization (thickness, roughness and density) of virgin samples and plasma exposed samples was done by soft x-ray (λ=80 Å) reflectivity measurements at Indus-1 reflectivity beam line. Different gas plasma removes carbon with different rate (0.4 to 0.65 nm /min). A thin layer 2 to 9 nm of different roughness and density is observed at the top surface of tungsten film. Ar gas plasma is found more suitable for cleaning of tungsten surface.

  14. Plastic deformation to enhance plasma-assisted nitriding: On surface contamination induced by Surface Mechanical Attrition Treatment

    International Nuclear Information System (INIS)

    Samih, Youssef; Novelli, Marc; Bolle, Bernard; Allain, Nathalie; Fundenberger, Jean-Jacques; Marcos, Grégory; Czerwiec, Thierry; Grosdidier, Thierry; Thiriet, Tony

    2014-01-01

    The Surface Mechanical Attrition Treatment is a recent technique leading to the formation of nanostructured layers by the repeated action of impacting balls. While several communications have revealed possible contamination of the SMATed surfaces, the nature of this surface contamination was analyzed in the present contribution for the treatment of an AISI 316L stainless steel. It is shown, by a combination of Transmission Electron Microscopy and Glow Discharge – Optical Emission Spectrometry, that the surface was alloyed with Ti, Al and V coming from the sonotrode that is used to move the balls as well as Zr coming from the zirshot® balls themselves

  15. Plastic deformation to enhance plasma-assisted nitriding: On surface contamination induced by Surface Mechanical Attrition Treatment

    Science.gov (United States)

    Samih, Youssef; Novelli, Marc; Thiriet, Tony; Bolle, Bernard; Allain, Nathalie; Fundenberger, Jean-Jacques; Marcos, Grégory; Czerwiec, Thierry; Grosdidier, Thierry

    2014-08-01

    The Surface Mechanical Attrition Treatment is a recent technique leading to the formation of nanostructured layers by the repeated action of impacting balls. While several communications have revealed possible contamination of the SMATed surfaces, the nature of this surface contamination was analyzed in the present contribution for the treatment of an AISI 316L stainless steel. It is shown, by a combination of Transmission Electron Microscopy and Glow Discharge - Optical Emission Spectrometry, that the surface was alloyed with Ti, Al and V coming from the sonotrode that is used to move the balls as well as Zr coming from the zirshot® balls themselves.

  16. Levels of surface contamination with radioactive materials at workplaces of nuclear research centre at Rez

    International Nuclear Information System (INIS)

    Hoelgye, Z.; Nemcova, I.; Kasikova, M.; Popper, J.; Chysky, J.

    1983-01-01

    A hygiene supervision unit at workplaces of the nuclear Research Institute in Rez monitored on a long-term basis surface contamination with radioactive substances. Surface contamination was found at workplaces with open sources. Of the 4343 monitored places action levels were only exceeded in 13 cases. The obtained data were used for typifying workplaces with the highest level of surface contamination, to determine in certain instances the mechanism of the escape of radioactive substances from insulating facilities and to determine the rate of the spread of the radioactive substance into adjacent non-active workplaces. (author)

  17. Bioremediation of hydrocarbon contaminated surface water, groundwater, and soils

    International Nuclear Information System (INIS)

    Piotrowski, M.R.

    1991-01-01

    Bioremediation is currently receiving considerable attention as a remediation option for sites contaminated with hazardous organic compounds. There is an enormous amount of interest in bioremediation, and numerous journals now publish research articles concerning some aspect of the remediation approach. A review of the literature indicates that two basic forms of bioremediation are currently being practiced: the microbiological approach and the microbial ecology approach. Each form has its advocates and detractors, and the microbiological approach is generally advocated by most of the firms that practice bioremediation. In this paper, the merits and disadvantages of these forms are reviewed and a conceptual approach is presented for assessing which form may be most useful for a particular contaminant situation. I conclude that the microbial ecology form of bioremediation may be the most useful for the majority of contaminant situations, and I will present two case histories in support of this hypothesis

  18. Laboratory Studies on Surface Sampling of Bacillus anthracis Contamination: Summary, Gaps, and Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F.; Amidan, Brett G.; Hu, Rebecca

    2011-11-28

    This report summarizes previous laboratory studies to characterize the performance of methods for collecting, storing/transporting, processing, and analyzing samples from surfaces contaminated by Bacillus anthracis or related surrogates. The focus is on plate culture and count estimates of surface contamination for swab, wipe, and vacuum samples of porous and nonporous surfaces. Summaries of the previous studies and their results were assessed to identify gaps in information needed as inputs to calculate key parameters critical to risk management in biothreat incidents. One key parameter is the number of samples needed to make characterization or clearance decisions with specified statistical confidence. Other key parameters include the ability to calculate, following contamination incidents, the (1) estimates of Bacillus anthracis contamination, as well as the bias and uncertainties in the estimates, and (2) confidence in characterization and clearance decisions for contaminated or decontaminated buildings. Gaps in knowledge and understanding identified during the summary of the studies are discussed and recommendations are given for future studies.

  19. Exploring Surface Analysis Techniques for the Detection of Molecular Contaminants on Spacecraft

    Science.gov (United States)

    Rutherford, Gugu N.; Seasly, Elaine; Thornblom, Mark; Baughman, James

    2016-01-01

    Molecular contamination is a known area of concern for spacecraft. To mitigate this risk, projects involving space flight hardware set requirements in a contamination control plan that establishes an allocation budget for the exposure of non-volatile residues (NVR) onto critical surfaces. The purpose of this work will focus on non-contact surface analysis and in situ monitoring to mitigate molecular contamination on space flight hardware. By using Scanning Electron Microscopy and Energy Dispersive Spectroscopy (SEM-EDS) with Raman Spectroscopy, an unlikely contaminant was identified on space flight hardware. Using traditional and surface analysis methods provided the broader view of the contamination sources allowing for best fit solutions to prevent any future exposure.

  20. Conformational change of oil contaminants adhered onto crystalline alpha-alumina surface in aqueous solution

    International Nuclear Information System (INIS)

    Xie, Wenkun; Sun, Yazhou; Liu, Haitao; Fu, Hongya; Liang, Yingchun

    2016-01-01

    Graphical abstract: - Highlights: • Dynamic conformational change process of oil contaminations adhered onto Al-terminated α-Al_2O_3 surface in aqueous solution is given. • Effect of water penetration on the conformational change and even detachment of oil contaminants is considered. • Change of driving forces leading to the conformational change of oil contaminants is described. - Abstract: Microscopic conformational change of oil contaminants adhered onto perfect α-Al_2O_3 (0001) surface in the aqueous solution was simulated by means of detailed fully atomistic molecular dynamics simulations. The main driving forces of the conformation change process of the oil contaminants were explored. The simulation results indicate that with submerging of the contaminated α-Al_2O_3 (0001) surface into the aqueous solution, the oil contaminants undertake an evident conformational change process. The dynamic process can be divided into several stages, including early penetration of water molecules, formation and widening of water channel, and generation of molecularly adsorbed hydration layers. Moreover, the oil contaminants on the α-Al_2O_3 surface are not fully removed from solid surface after a 10 ns relaxation, while a relatively stable oil/water/solid three-phase interface is gradually formed. Further, the residual oil contaminants are finally divided into several new ordered molecular adsorption layers. In addition, by systemically analyzing the driving forces for the conformational change of the oil contaminants, the penetration of water molecules is found to be the most important driving force. With penetrating of the water molecules, the dominating interactions controlling the conformational change of the oil contaminants have been changing over the whole simulation.

  1. Liquid scintillation cocktails comparison for tritium contamination measurements

    International Nuclear Information System (INIS)

    Bazzarri, S.; Belloni, P.

    1996-01-01

    Liquid scintillation counting is one of the most used techniques for the measurements of tritium contamination. Until few years ago a problem related to this kind of measurement was the potential toxicity of the liquid cocktails used to produce the required scintillation. Some new products that guarantee an almost negligible impact on the environment and that are no longer toxic for the operators are now available. Some of this new scintillation cocktail are suitable to be used for tritium measurement. Due to the great benefit from the health point of view of these new materials a test of their scintillation performance has been done at the ENEA centers to select the product having the best characteristics for tritium measurement. (author)

  2. A risk-informed basis for establishing non-fixed surface contamination limits for spent fuel transportation casks

    International Nuclear Information System (INIS)

    Rawl, R.R.; Eckerman, K.F.; Bogard, J.S.; Cook, J.R.

    2004-01-01

    The current limits for non-fixed contamination on packages used to transport radioactive materials were introduced in the 1961 edition of the International Atomic Energy Agency (IAEA) transport regulations and were based on radiation protection guidance and practices in use at that time. The limits were based on exposure scenarios leading to intakes of radionuclides by inhalation and external irradiation of the hands. These considerations are collectively referred to as the Fairbairn model. Although formulated over 40 years ago, the model remains unchanged and is still the basis of current regulatory-derived limits on package non-fixed surface contamination. There can also be doses that while not resulting directly from the contamination, are strongly influenced by and attributable to transport regulatory requirements for contamination control. For example, actions necessary to comply with the current derived limits for light-water-reactor (LWR) spent nuclear fuel (SNF) casks can result in significant external doses to workers. This is due to the relatively high radiation levels around the loaded casks, where workers must function during the measurement of contamination levels and while decontaminating the cask. In order to optimize the total dose received due to compliance with cask contamination levels, it is necessary to take into account all the doses that vary as a result of the regulatory limit. Limits for non-fixed surface contamination on spent fuel casks should be established by using a model that considers and optimizes the appropriate exposure scenarios both in the workplace and in the public environment. A risk-informed approach is needed to ensure optimal use of personnel and material resources for SNF-based packaging operations. This paper is a summary of a study sponsored by the US Nuclear Regulatory Commission and performed by Oak Ridge National Laboratory that examined the dose implications for removable surface contamination limits on spent fuel

  3. Nickel, Lead and Zinc Contamination in the Surface Sediments of Agh Gel Wetland, Iran

    Directory of Open Access Journals (Sweden)

    Soheil Sobhan Ardakani

    2016-07-01

    Full Text Available Background & Aims of the Study: Due to the increased human activities around the Agh Gel wetland, this study aimed to measured accumulations of heavy metals (Ni, Pb and Zn in the surface sediment samples taken from this wetland. Materials & Methods: Samples were taken from 10 stations and exposed to bulk digestion and chemical partitioning. Finally, Ni, Pb and Zn concentrations were monitored with ICP-OES in the sediments. Also, geo-accumulation index, contamination factor and pollution load index were used to evaluate the magnitude of contaminants in the sediment profile. Results: The results showed, the average of metal concentration in samples (mg kg-1 wet weight were 34.20±3.58 for Ni, 25.37±2.52 for Pb and 127.20±15.21 for Zn, respectively. Therefore, the pattern of metal concentrations in sediment was determined as Zinc>Nickel >Lead. According to the mean I-geo values, sediments' qualities are classified as unpolluted category for Ni and Pb. Also, sediment's quality is classified as unpolluted to moderately polluted for Zn. The CF values for all elements are classified as moderate contamination. The PLI values indicated that metal pollution exists for all sampling stations. Conclusions: The obtained results indicated that the Agh Gel wetland has a potential to threaten by chemical pollutants such as agricultural effluent. So, in order to preserve the environment of the Agh Gel wetland from deterioration, monitoring of water and sediment qualities is recommended periodically.

  4. Measurement of radioactive contamination and decontamination on wooden exteriors and garden trees in Northern Fukushima Prefecture

    International Nuclear Information System (INIS)

    Sugiura, Hiroyuki; Kawano, Keisuke; Kayama, Yukihiko

    2012-01-01

    Measurement and decontamination of surface of trees and surrounding wooden structures contaminated by radioactive substance were studied in the gardens and public parks of Northern Fukushima Prefecture which experienced radioactive contamination due to the accident at the TEPCO's Fukushima Daiichi Nuclear Power Plant. The counts per minute (CPM) above the centre surface of wooden garden tables in open air were 1.5 times higher than those of garden benches and 9 times higher than that of a garden bench in the square gazebo. Decontamination of wooden garden benches by high-pressure washing was more effective than planing. The counts per minute (CPM) above the soil around garden trees increased by 1.2 times after high-pressure washing. Radioactivity counting rate did not decrease when the leaves fallen from zelocova trees were removed; however, they decreased by about half when soil cover was installed at the base of the trees. Clearly, the upper surfaces of garden trees and wooden surrounding structures were strongly contaminated by radioactive substances, and they should be decontaminated by high-pressure washing before removing the surface soil. (author)

  5. Soil contamination of plant surfaces from grazing and rainfall interactions

    International Nuclear Information System (INIS)

    Hinton, T.G.; Stoll, J.M.; Tobler, L.

    1995-01-01

    Contaminants often attach to soil particles, and their subsequent environmental transport is largely determined by processes that govern soil movement. We examined the influence of grazing intensity on soil contamination of pastures. Four different grazing densities of sheep were tested against an ungrazed control plot. Scandium concentrations were determined by neutron activation analysis and was used as a tracer of soil adhesion on vegetation. Soil loadings ( g soil kg -1 dry plant) increased 60% when grazing intensity was increased by a factor of four (p 0.003). Rain and wind removed soil from vegetation in the ungrazed control plots, but when grazing sheep were present, an increase in rain from 0.3 to 9.7 mm caused a 130% increase in soil contamination. Multiple regression was used to develop an equation that predicts soil loadings as a function of grazing density, rainfall and wind speed (p = 0.0001, r 2 = 0.78). The model predicts that if grazing management were to be used as a tool to reduce contaminant intake from inadvertent consumption of resuspended soil by grazing animals, grazing densities would have to be reduced 2.5 times to reduce soil loadings by 50%. (author)

  6. Metal Hydride assited contamination on Ru/Si surfaces

    NARCIS (Netherlands)

    Pachecka, Malgorzata; Lee, Christopher James; Sturm, Jacobus Marinus; Bijkerk, Frederik

    2013-01-01

    In extreme ultraviolet lithography (EUVL) residual tin, in the form of particles, ions, and atoms, can be deposited on nearby EUV optics. During the EUV pulse, a reactive hydrogen plasma is formed, which may be able to react with metal contaminants, creating volatile and unstable metal hydrides that

  7. Radioactive air and surface contamination in Czechia and Slovakia

    International Nuclear Information System (INIS)

    Rumyantsev, V.V.

    1992-01-01

    Data are presented on the radioactive substance effluents into the environment in conditions of NPP normal operation and on the air contamination by 85 Kr due to operation of the European and Soviet plants for reprocessing spent nuclear fuel. Data are given on the dosage of the Czechoslovakia population due to the Chernobyl NPP accident

  8. Contact area measurements on structured surfaces

    DEFF Research Database (Denmark)

    Kücükyildiz, Ömer Can; Jensen, Sebastian Hoppe Nesgaard; De Chiffre, Leonardo

    In connection with the use of brass specimens featuring structured surfaces in a tribology test, an algorithm was developed for automatic measurement of the contact area by optical means.......In connection with the use of brass specimens featuring structured surfaces in a tribology test, an algorithm was developed for automatic measurement of the contact area by optical means....

  9. Nuclear electronic components of surface contamination monitor based on multi-electrode proportional counter

    International Nuclear Information System (INIS)

    Du Xiangyang; Zhang Yong; Han Shuping; Rao Xianming; Fang Jintu

    2001-01-01

    The nuclear electronic components applying in Portal Monitor and Hands and Feet Surface Contamination Monitor were based on modern integrated circuit are introduced. The detailed points in circuit design and manufacturing technique are analyzed

  10. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects.

    LENUS (Irish Health Repository)

    Mohamed, Seif

    2010-05-01

    This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite with that around Nanotite implants.

  11. National Enforcement Initiative: Preventing Animal Waste from Contaminating Surface and Ground Water

    Science.gov (United States)

    This page describes EPA's goal in preventing animal waste from contaminating surface and ground Water. It is an EPA National Enforcement Initiative. Both enforcement cases, and a map of enforcement actions are provided.

  12. Hand Monitor for Simultaneous Measurements of Alpha and Beta Contamination

    International Nuclear Information System (INIS)

    Andersson, I.Oe.; Braun, J.; Soederlund, B.

    1960-11-01

    An instrument is described which measures α and β contamination of the hands simultaneously. This has been achieved by using as detectors 8 flow counters paired in 4 units of two chambers, one unit for each side of the hand. The inner chamber of every unit (adjacent to the hands) delivers α-pulses, the outer chambers deliver β-pulses. When two finger contacts are pushed the detectors are closing around the hands and the measurement is started. Audible and visual warnings operate when the MPL is exceeded. Similar warnings ope.rate if hands are removed before the end of the counting period. The activity levels are logarithmically indicated on four pointer instruments, which are automatically zeroed when the next measurement is started. The instrument is now commercially available

  13. Hand Monitor for Simultaneous Measurements of Alpha and Beta Contamination

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, I Oe; Braun, J; Soederlund, B

    1960-11-15

    An instrument is described which measures {alpha} and {beta} contamination of the hands simultaneously. This has been achieved by using as detectors 8 flow counters paired in 4 units of two chambers, one unit for each side of the hand. The inner chamber of every unit (adjacent to the hands) delivers {alpha}-pulses, the outer chambers deliver {beta}-pulses. When two finger contacts are pushed the detectors are closing around the hands and the measurement is started. Audible and visual warnings operate when the MPL is exceeded. Similar warnings ope.rate if hands are removed before the end of the counting period. The activity levels are logarithmically indicated on four pointer instruments, which are automatically zeroed when the next measurement is started. The instrument is now commercially available.

  14. Mouldboard ploughing as a remedial measure for contaminated land

    International Nuclear Information System (INIS)

    Loensjoe, H.

    1985-01-01

    In the case of a nuclear power plant accident, farmland would be contaminated by radioactive fall-out. The possibilities of restoring such land under Swedish conditions are under investigation. One of the means to reduce the external radiation and limit the plant uptake of the long-lived fission products, is mouldboard ploughing for placement of the contaminated soil surface layer deep in comparison to subsequent soil management operations. A series of ploughing experiments, using MgSO 4 . H 2 O as a tracer, have been performed in order to study the effectiveness of such operations in practical agriculture. Various types of ploughs used in Sweden have been tested on different soil types and vegetation beds. The results show that the activity to some extent will be distributed in the top soil layer, thus giving a reversed triangular or reversed exponential distribution in the soil profile. The external gamma radiation exposure from 137 Cs is estimated to be reduced by a factor of appr. 8-15 after ploughing, depending on type of plough and working depth

  15. Mapping possible flowpaths of contaminants through surface and cross-borehole spectral time-domain induced polarization

    DEFF Research Database (Denmark)

    Bording, Thue Sylvester; Fiandaca, Gianluca; Maurya, Pradip Kumar

    Traditional methods for mapping possible flowpaths of contaminants in sedimentary environments by boreholes may often be insufficient. Additional information may be acquired by geophysical methods. In the present study, cross-borehole and surface measurements were performed using time-domain indu......-domain induced polarization (TDIP). After measurements the entire test site was dug out, and the geology was described. A 2D spectral inversion of the combined dataset is presented, which is in great correspondence with the observed geology....

  16. Environmental Measurement-While-Drilling system for real-time field screening of contaminants

    International Nuclear Information System (INIS)

    Lockwood, G.J.; Normann, R.A.; Bishop, L.B.; Floran, R.J.; Williams, C.V.

    1995-01-01

    Sampling during environmental drilling is essential to fully characterize the spatial distribution and migration of near surface contaminants. However, the analysis of these samples is not only expensive, but can take weeks or months when sent to an off-site laboratory. In contrast, measurement-while-drilling (MWD) screening capability could save money and valuable time by quickly distinguishing between contaminated and uncontaminated areas. Real-time measurements provided by a MVM system would enable on-the-spot decisions to be made regarding sampling strategies, enhance worker safety, and provide the added flexibility of being able to ''steer'' the drill bit in or out hazardous zones. During measurement-while-drilling, down-hole sensors are located behind the drill bit and linked by a rapid data transmission system to a computer at the surface. As drilling proceeds, data are collected on the nature and extent of the subsurface contamination in real-time. The down-hole sensor is a Geiger-Mueller tube (GMT) gamma radiation detector. In addition to the GMT signal, the MWD system monitors these required down-hole voltages and two temperatures associated with the detector assembly. The Gamma Ray Detection System (GRDS) and electronics package are discussed in as well as the results of the field test. Finally, our conclusions and discussion of future work are presented

  17. Radon measurements over a natural-gas contaminated aquifer

    International Nuclear Information System (INIS)

    Palacios, D.; Fusella, E.; Avila, Y.; Salas, J.; Teixeira, D.; Fernández, G.; Salas, A.; Sajo-Bohus, L.; Greaves, E.; Barros, H.; Bolívar, M.; Regalado, J.

    2013-01-01

    Radon and thoron concentrations in soil pores in a gas production region of the Anzoategui State, Venezuela, were determined by active and passive methods. In this region, water wells are contaminated by natural gas and gas leaks exist in the nearby river. Based on soil gas Radon data surface hydrocarbon seeps were identified. Radon and thoron concentration maps show anomalously high values near the river gas leaks decreasing in the direction of water wells where natural gas is also detected. The area where the highest concentrations of 222 Rn were detected seems to indicate the surface projection of the aquifer contaminated with natural gas. The Radon/Thoron ratio revealed a micro-localized anomaly, indicating the area where the gas comes from deep layers of the subsoil. The radon map determined by the passive method showed a marked positive anomaly around abandoned gas wells. The high anomalous Radon concentration localized near the trails of ascending gas bubbles at the river indicates the zone trough where natural gases are ascending with greater ease, associated with a deep geological fault, being this the main source of methane penetration into the aquifer. It is suggested that the source of the natural gas may be due to leaks at deep sites along the structure of some of the abandoned wells located at the North-East of the studied area. - Highlights: ► High Radon/Thoron ratios were localized near the natural-gas emanations in a river. ► Natural gases are ascending trough a deep geological fault. ► Apparently, the radon anomaly shows the site where natural gas enters the aquifer. ► Natural gas source may be related to leaks in the structure of abandoned gas wells

  18. Aspheric surface measurement using capacitive probes

    Science.gov (United States)

    Tao, Xin; Yuan, Daocheng; Li, Shaobo

    2017-02-01

    With the application of aspheres in optical fields, high precision and high efficiency aspheric surface metrology becomes a hot research topic. We describe a novel method of non-contact measurement of aspheric surface with capacitive probe. Taking an eccentric spherical surface as the object of study, the averaging effect of capacitive probe measurement and the influence of tilting the capacitive probe on the measurement results are investigated. By comparing measurement results from simultaneous measurement of the capacitive probe and contact probe of roundness instrument, this paper indicates the feasibility of using capacitive probes to test aspheric surface and proposes the compensation method of measurement error caused by averaging effect and the tilting of the capacitive probe.

  19. Surface texture measurement for dental wear applications

    Science.gov (United States)

    Austin, R. S.; Mullen, F.; Bartlett, D. W.

    2015-06-01

    The application of surface topography measurement and characterization within dental materials science is highly active and rapidly developing, in line with many modern industries. Surface measurement and structuring is used extensively within oral and dental science to optimize the optical, tribological and biological performance of natural and biomimetic dental materials. Although there has historically been little standardization in the use and reporting of surface metrology instrumentation and software, the dental industry is beginning to adopt modern areal measurement and characterization techniques, especially as the dental industry is increasingly adopting digital impressioning techniques in order to leverage CAD/CAM technologies for the design and construction of dental restorations. As dental treatment becomes increasingly digitized and reliant on advanced technologies such as dental implants, wider adoption of standardized surface topography and characterization techniques will become evermore essential. The dental research community welcomes the advances that are being made in surface topography measurement science towards realizing this ultimate goal.

  20. Evaluation and assessment of baseline metal contamination in surface sediments from the Bernam River, Malaysia.

    Science.gov (United States)

    Kadhum, Safaa A; Ishak, Mohd Yusoff; Zulkifli, Syaizwan Zahmir

    2016-04-01

    The Bernam River is one of the most important rivers in Malaysia in that it provides water for industries and agriculture located along its banks. The present study was conducted to assess the level of contamination of heavy metals (Cd, Ni, Cr, Sn, and Fe) in surface sediments in the Bernam River. Nine surface sediment samples were collected from the lower, middle, and upper courses of the river. The results indicated that the concentrations of the metals decreased in the order of Sn > Cr > Ni > Fe > Cd (56.35, 14.90, 5.3, 4.6, and 0.62 μg/g(1) dry weight). Bernam River sediments have moderate to severe enrichment for Sn, moderate for Cd, and no enrichment for Cr, Ni, and Fe. The contamination factor (CF) results demonstrated that Cd and Sn are responsible for the high contamination. The pollution load index (PLI), for all the sampling sites, suggests that the sampling stations were generally unpolluted with the exception of the Bagan Tepi Sungai, Sabak Bernam, and Tanjom Malim stations. Multivariate techniques including Pearson's correlation and hierarchical cluster analysis were used to apportion the various sources of the metals. The results suggested that the sediment samples collected from the upper course of the river had lower metal concentrations, while sediments in the middle and lower courses of the river had higher metal concentrations. Therefore, our results can be useful as a baseline data for government bodies to adopt corrective measure on the issues related to heavy metal pollution in the Bernam River in the future.

  1. Comparison between ex situ and in situ measurement methods for the assessment of radioactively contaminated land. Comparison between measurement methods for the characterisation of radioactively contaminated land

    International Nuclear Information System (INIS)

    Rostron, Peter D.; Ramsey, Michael H.; Heathcote, John A.

    2012-01-01

    In the UK, it is estimated that there may be 20,000,000 cubic metres of contaminated land at Sellafield alone. Harwell and Dounreay are known to have significant amounts of radioactive or nonradioactive contaminated land (NDA, 2006). It is therefore important to devise optimal methods for the characterisation of areas of land for radionuclide content, in order to enable cost-effective decommissioning. With chemical contaminants, ex situ measurements are made on a larger volume of soil than are in situ measurements, such as PXRF. However, the opposite is often true for the characterisation of radioactive contamination, when this involves the detection of penetrating radiation from γ-emitting radionuclides. This means that when investigating for hotspots of radioactive contamination at or near the ground surface, better coverage can be obtained using in situ methods. This leads to the question, what is the optimal strategy (e.g. percentage coverage, counting time) for in situ characterisation of radioactively contaminated land' Surveys on light-moderate contaminated areas of ground were conducted at Dounreay in order to compare the relative effectiveness of in situ and ex situ methods, both for the detection of radioactive hotspots and also for estimating the average radionuclide content of an area of ground. These surveys suggest that continuous coverage by in situ devices is more effective at hotspot detection, with ex situ laboratory measurements being less effective, although in one case elevated activity below 10 cm depth that was identified by ex situ measurement was not located by in situ measurement. The surveys also highlighted that careful choice of an appropriate spatial model is critical to the estimation of activity concentrations over averaging areas. Whereas continuous coverage may be considered necessary for hotspot identification, in the particular case of the detection of hot particles (where the particle is very small compared to the sampling

  2. Non destructive measurement for the penetration of contamination inside concrete walls

    International Nuclear Information System (INIS)

    Rottner, B.

    1998-01-01

    The scope of this work is to determine the penetration depth of the contamination inside materials like concrete, only using external measurements, avoiding for instance to drill holes in the concrete wall. When dismantling NPP, concrete represents a significant part of the amount of waste. It is then interesting to segregate concrete into different types of waste: ordinary waste, very low level active waste,... This method makes it possible to generate a three dimensional map of the contamination in a concrete wall; this map car be used to adapt the dismantling scenario, and the tools, in order to: - first: decontaminate the wall by scraping the identified contaminated parts, which generates a small quantity of active waste; - second: break down the wall using non nuclear specific methods, generating a large quantity of ordinary waste. The method is based on spectrometric measurements, using two types of information: - the peak to peak ratios for a single radio-nuclide; - the ratio of the peak surface to the baseline enhancement under the peak. Both ratios vary with the penetration depth of the contamination, but rot in the same way. Therefore, the information which is used, will preferably depends on the depth. The correlation of the two ratios to the penetration depth is computed, using two specific calculation codes. One computes the sensitivity of the detector to the direct rays and the other computes the spectrum shape. (author)

  3. EM Task 12 - Laser cleaning of Contaminated Painted Surfaces

    International Nuclear Information System (INIS)

    Ames A. Grisanti; Charlene R. Crocker; Robert J. Jensen

    1998-01-01

    Several techniques are available or under development for surface decontamination in nuclear facilities. Each technique has its merits; however, none of them is universally the best choice for all surface decontamination applications. Because of the multitude of factors which influence the environmental and economic aspects of selecting a surface decontamination technique, it is difficult to select the best method in a given situation; an objective basis for comparing techniques is needed. The objective of this project is to develop a software tool for use by personnel selecting a surface decontamination technique. The software will incorporate performance data for available surface decontamination techniques. The beta release of the Surface Decontamination Assistant Software has been completed and has undergone testing at the Energy and Environmental Research Center (EERC). Minor modifications to the software will be completed before the end of November 1998, and a final release of the software will be issued

  4. EM Task 12 - Laser cleaning of contaminated painted surfaces

    International Nuclear Information System (INIS)

    Grisanti, Ames A.; Crocker, Charlene R.; Jensen, Robert R.

    1999-01-01

    Several techniques are available or under development for surface decontamination in nuclear facilities. Each technique has its merits; however, none of them is universally the best choice for all surface decontamination applications. Because of the multitude of factors which influence the environmental and economic aspects of selecting a surface decontamination technique, it is difficult to select the best method in a given situation; an objective basis for comparing techniques is needed. The objective of this project was to develop a software tool for use by personnel selecting a surface decontamination technique. The software incorporates performance data for available surface decontamination techniques. The beta release version of the Surface Decontamination Assistant Software has been completed and has undergone testing at the Energy and Environmental Research Center. Minor modifications to the software were completed, and a final release version of the software is ready to be issued

  5. Surface texture measurement for additive manufacturing

    Science.gov (United States)

    Triantaphyllou, Andrew; Giusca, Claudiu L.; Macaulay, Gavin D.; Roerig, Felix; Hoebel, Matthias; Leach, Richard K.; Tomita, Ben; Milne, Katherine A.

    2015-06-01

    The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting.

  6. Surface texture measurement for additive manufacturing

    International Nuclear Information System (INIS)

    Triantaphyllou, Andrew; Tomita, Ben; Milne, Katherine A; Giusca, Claudiu L; Macaulay, Gavin D; Roerig, Felix; Hoebel, Matthias; Leach, Richard K

    2015-01-01

    The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting. (paper)

  7. Fate factors and emission flux estimates for emerging contaminants in surface waters

    Directory of Open Access Journals (Sweden)

    Hoa T. Trinh

    2016-01-01

    Full Text Available Pharmaceuticals, personal care products, hormones, and wastewater products are emerging environmental concerns for manifold reasons, including the potential of some compounds found in these products for endocrine disruption at a very low chronic exposure level. The environmental occurrences and sources of these contaminants in the water, soil, sediment and biota in European nations and the United States are well documented. This work reports a screening-level emission and fate assessment of thirty compounds, listed in the National Reconnaissance of the United States Geological Survey (USGS, 1999–2000 as the most frequently detected organic wastewater contaminants in U.S. streams and rivers. Estimations of the surface water fate factors were based on Level II and Level III multimedia fugacity models for a 1000 km2 model environment, the size of a typical county in the eastern United States. The compounds are categorized into three groups based upon the sensitivity of their predicted surface water fate factors to uncertainties in their physicochemical property values and the landscape parameters. The environmental fate factors, mass distributions, and loss pathways of all of the compounds are strongly affected by their assumed modes of entry into the environment. It is observed that for thirteen of the thirty organic wastewater contaminants most commonly detected in surface waters, conventional treatment strategies may be ineffective for their removal from wastewater effluents. The surface water fate factors predicted by the fugacity models were used in conjunction with the surface water concentrations measured in the USGS reconnaissance to obtain emission flux estimates for the compounds into U.S. streams and rivers. These include estimated fluxes of 6.8 × 10−5 to 0.30 kg/h km2 for the biomarker coprostanol; 1.7 × 10−5 to 6.5 × 10−5 kg/h km2 for the insect repellent N,N-diethyltoluamide; and 4.3 × 10−6 to 3.1 × 10−5 kg/h km2 for

  8. Study of surface potential contamination in radioisotope and radiopharmaceutical production facilities and alternative solutions

    International Nuclear Information System (INIS)

    Suhaedi Muhammad; Rimin Sumantri; Farida Tusafariah; Djarwanti Rahayu Pipin Soedjarwo

    2013-01-01

    Radioisotope and radiopharmaceutical production facilities that exist in their operations around the world in the form of radiological impacts of radiation exposure, contamination of surface and air contamination. Given the number of existing open source in radioisotope and radiopharmaceutical production facility, then the possibility of surface contamination in the work area is quite high. For that to protect the safety and health of both workers, the public and the environment, then the licensee must conduct an inventory of some of the potential that could result in contamination of surfaces in radioisotope and radiopharmaceutical production facilities. Several potential to cause surface contamination in radioisotope and radiopharmaceutical production facilities consist of loss of resources, the VAC system disorders, impaired production facilities, limited resources and lack of work discipline and radioactive waste handling activities. From the study of some potential, there are several alternative solutions that can be implemented by the licensee to address the contamination of the surface so as not to cause adverse radiological impacts for both radiation workers, the public or the environment. (author)

  9. Atmospheric-Pressure Plasma Cleaning of Contaminated Surfaces

    International Nuclear Information System (INIS)

    Hicks, Robert F.; Herrmann, Hans W.

    2003-01-01

    The objective of this work is to demonstrate a practical, atmospheric pressure plasma tool for the surface decontamination of radioactive waste. Decontamination of radioactive materials that have accumulated on the surfaces of equipment and structures is a challenging and costly undertaking for the US Department of Energy. Our technology shows great potential for accelerating this clean up effort

  10. Contamination of Optical Surfaces Under Irradiation by Outgassed Volatile Products

    International Nuclear Information System (INIS)

    Khasanshin, R. H.; Grigorevskiy, A. V.; Galygin, A. N.; Alexandrov, N. G.

    2009-01-01

    Deposition of outgassed products of a polymeric composite on model material surfaces being irradiated by electrons and protons with initial energies of E e = 40 keV and E p = 30 keV respectively was studied. It was shown that deposition of volatile products on model material surfaces being under ionizing radiations results in increase of organic film growth rate.

  11. Measuring Light Reflectance of BGO Crystal Surfaces

    Science.gov (United States)

    Janecek, Martin; Moses, William W.

    2008-10-01

    A scintillating crystal's surface reflectance has to be well understood in order to accurately predict and optimize the crystal's light collection through Monte Carlo simulations. In this paper, we measure the inner surface reflectance properties for BGO. The measurements include BGO crystals with a mechanically polished surface, rough-cut surface, and chemically etched surface, and with various reflectors attached, both air-coupled and with coupling compound. The measurements are performed with a laser aimed at the center of a hemispherical shaped BGO crystal. The hemispherical shape eliminates any non-perpendicular angles for light entering and exiting the crystal. The reflected light is collected with an array of photodiodes. The laser can be set at an arbitrary angle, and the photodiode array is rotated to fully cover 2pi of solid angle. The current produced in the photodiodes is readout with a digital multimeter connected through a multiplexer. The two rows of photodiodes achieve 5-degree by 4-degree resolution, and the current measurement has a dynamic range of 105:1. The acquired data was not described by the commonly assumed linear combination of specular and diffuse (Lambertian) distributions, except for a very few surfaces. Surface roughness proved to be the most important parameter when choosing crystal setup. The reflector choice was of less importance and of almost no consequence for rough-cut surfaces. Pure specular reflection distribution for all incidence angles was measured for polished surfaces with VM2000 film, while the most Lambertian distribution for any surface finish was measured for titanium dioxide paint. The distributions acquired in this paper will be used to create more accurate Monte Carlo models for light reflection distribution within BGO crystals.

  12. The aftermath of the Fukushima nuclear accident: Measures to contain groundwater contamination

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, Adrian H., E-mail: adgallardo@geowater.com.au [CONICET (Argentina National Scientific and Technical Research Council), San Luis National University, FCFMyN, Department of Geology, San Luis 5700 (Argentina); Marui, Atsunao [AIST Geological Survey of Japan, Geo-Resources and Environment Institute, Groundwater Research Group, Ibaraki-ken, Tsukuba 305-8567 (Japan)

    2016-03-15

    Several measures are being implemented to control groundwater contamination at the Fukushima Daiichi Nuclear Plant. This paper presents an overview of work undertaken to contain the spread of radionuclides, and to mitigate releases to the ocean via hydrological pathways. As a first response, contaminated water is being held in tanks while awaiting treatment. Limited storage capacity and the risk of leakage make the measure unsustainable in the long term. Thus, an impervious barrier has been combined with a drain system to minimize the discharge of groundwater offshore. Caesium in seawater at the plant port has largely dropped, although some elevated concentrations are occasionally recorded. Moreover, a dissimilar decline of the radioactivity in fish could indicate additional sources of radionuclides intake. An underground frozen shield is also being constructed around the reactors. This structure would reduce inflows to the reactors and limit the interaction between fresh and contaminated waters. Additional strategies include groundwater abstraction and paving of surfaces to lower water levels and further restrict the mobilisation of radionuclides. Technical difficulties and public distrust pose an unprecedented challenge to the site remediation. Nevertheless, the knowledge acquired during the initial work offers opportunities for better planning and more rigorous decisions in the future. - Highlights: • Measures are being undertaken to manage groundwater contamination in Fukushima. • Methods focus on isolating the source and controlling the radionuclides migration. • Wastewater is being temporarily held in tanks for treatment. • Impervious walls inhibit the transport of contaminants toward the ocean. • Paving and pumping further mitigate the dispersion of pollutants by water.

  13. Geometric Measure Theory and Minimal Surfaces

    CERN Document Server

    Bombieri, Enrico

    2011-01-01

    W.K. ALLARD: On the first variation of area and generalized mean curvature.- F.J. ALMGREN Jr.: Geometric measure theory and elliptic variational problems.- E. GIUSTI: Minimal surfaces with obstacles.- J. GUCKENHEIMER: Singularities in soap-bubble-like and soap-film-like surfaces.- D. KINDERLEHRER: The analyticity of the coincidence set in variational inequalities.- M. MIRANDA: Boundaries of Caciopoli sets in the calculus of variations.- L. PICCININI: De Giorgi's measure and thin obstacles.

  14. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    Directory of Open Access Journals (Sweden)

    Adilson Yoshio Furuse

    2007-12-01

    Full Text Available The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1 rinsing with water and drying; (G2 application of an adhesive system; (G3 rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4 rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (p<0.05. Similar values to the original bond strength were obtained after abrasion and application of adhesive (G3 or etching and application of silane and adhesive (G4. If contamination occurs, a surface treatment is required to guarantee an adequate interaction between the resin increments.

  15. Measurement of atmospheric contamination by double mandarin (1961)

    International Nuclear Information System (INIS)

    Billard, F.; Miribel Pradel, J.

    1961-01-01

    - To check the radioactivity of the air in laboratories where plutonium is handled, an apparatus known as 'Double Mandarin' was devised. This instrument distinguishes plutonium dusts from those which carry natural active deposits, by making use of the granulometric difference between these two types of particle. The separation is based on the use of selective filters placed in series. An electronic unit enables the activities of the dusts collected on the two filters to be measured continuously and immediately. This apparatus is simple in design and should provide a means of checking atmospheric contamination. Its performance is particularly satisfactory in the case of laboratories where the air is filtered. Under these conditions it is possible to detect 70 times the CMA after one minute and 7 times this concentration in 10 minutes. (authors) [fr

  16. SUDOQU, a new dose-assessment methodology for radiological surface contamination.

    Science.gov (United States)

    van Dillen, Teun; van Dijk, Arjan

    2018-06-12

    A new methodology has been developed for the assessment of the annual effective dose resulting from removable and fixed radiological surface contamination. It is entitled SUDOQU (SUrface DOse QUantification) and it can for instance be used to derive criteria for surface contamination related to the import of non-food consumer goods, containers and conveyances, e.g., limiting values and operational screening levels. SUDOQU imposes mass (activity)-balance equations based on radioactive decay, removal and deposition processes in indoor and outdoor environments. This leads to time-dependent contamination levels that may be of particular importance in exposure scenarios dealing with one or a few contaminated items only (usually public exposure scenarios, therefore referred to as the 'consumer' model). Exposure scenarios with a continuous flow of freshly contaminated goods also fall within the scope of the methodology (typically occupational exposure scenarios, thus referred to as the 'worker model'). In this paper we describe SUDOQU, its applications, and its current limitations. First, we delineate the contamination issue, present the assumptions and explain the concepts. We describe the relevant removal, transfer, and deposition processes, and derive equations for the time evolution of the radiological surface-, air- and skin-contamination levels. These are then input for the subsequent evaluation of the annual effective dose with possible contributions from external gamma radiation, inhalation, secondary ingestion (indirect, from hand to mouth), skin contamination, direct ingestion and skin-contact exposure. The limiting effective surface dose is introduced for issues involving the conservatism of dose calculations. SUDOQU can be used by radiation-protection scientists/experts and policy makers in the field of e.g. emergency preparedness, trade and transport, exemption and clearance, waste management, and nuclear facilities. Several practical examples are worked

  17. Methods for Sampling and Measurement of Compressed Air Contaminants

    International Nuclear Information System (INIS)

    Stroem, L.

    1976-10-01

    In order to improve the technique for measuring oil and water entrained in a compressed air stream, a laboratory study has been made of some methods for sampling and measurement. For this purpose water or oil as artificial contaminants were injected in thin streams into a test loop, carrying dry compressed air. Sampling was performed in a vertical run, down-stream of the injection point. Wall attached liquid, coarse droplet flow, and fine droplet flow were sampled separately. The results were compared with two-phase flow theory and direct observation of liquid behaviour. In a study of sample transport through narrow tubes, it was observed that, below a certain liquid loading, the sample did not move, the liquid remaining stationary on the tubing wall. The basic analysis of the collected samples was made by gravimetric methods. Adsorption tubes were used with success to measure water vapour. A humidity meter with a sensor of the aluminium oxide type was found to be unreliable. Oil could be measured selectively by a flame ionization detector, the sample being pretreated in an evaporation- condensation unit

  18. Methods for Sampling and Measurement of Compressed Air Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Stroem, L

    1976-10-15

    In order to improve the technique for measuring oil and water entrained in a compressed air stream, a laboratory study has been made of some methods for sampling and measurement. For this purpose water or oil as artificial contaminants were injected in thin streams into a test loop, carrying dry compressed air. Sampling was performed in a vertical run, down-stream of the injection point. Wall attached liquid, coarse droplet flow, and fine droplet flow were sampled separately. The results were compared with two-phase flow theory and direct observation of liquid behaviour. In a study of sample transport through narrow tubes, it was observed that, below a certain liquid loading, the sample did not move, the liquid remaining stationary on the tubing wall. The basic analysis of the collected samples was made by gravimetric methods. Adsorption tubes were used with success to measure water vapour. A humidity meter with a sensor of the aluminium oxide type was found to be unreliable. Oil could be measured selectively by a flame ionization detector, the sample being pretreated in an evaporation- condensation unit

  19. Diamond blade grinding as a means for removing surface contamination from concrete

    International Nuclear Information System (INIS)

    Lynch, T.W.

    1980-01-01

    The use of a highway grinding unit for the decontamination of a 5,000 square foot surface is described. The type of equipment presently in use is described. Performance characteristics, waste collection and water usage are commented on. Variables in blade design are discussed. Feasibility of the grinding technique for water soluble contaminants and vertical surfaces is referred to

  20. Fixation of soil surface contamination using natural polysaccharides

    International Nuclear Information System (INIS)

    Sackschewsky, M.R.

    1993-09-01

    Natural polysaccharides were evaluated as alternatives to commercially available dust-control agents for application in buried-waste and contaminated-soil remediation situations. Materials were identified and evaluated with specific criteria in mind: the materials must be environmentally benign and must not introduce any additional hazardous materials; they must be effective for at least 2 or 3 days, but they do not necessarily have to be effective for more than 2 to 3 weeks; they should be relatively resistant to light traffic; they must not interfere with subsequent soil treatment techniques, especially soil washing; and they must be relatively inexpensive. Two products, a pregelled potato starch and a mixture of carbohydrates derived from sugar beets, were selected for evaluation. Testing included small- and large-scale field demonstrations, laboratory physical property analyses, and wind-tunnel evaluations

  1. Radiobiological significance of radioactive contamination - summary assessment based on great number of measurements

    International Nuclear Information System (INIS)

    Angelov, V.; Bonchev, Ts.; Mavrodiev, V.; Kyrdzhilov, N.

    1995-01-01

    In order to facilitate quantitative and qualitative characterisation of radioactive contamination the authors introduce a relative estimate of radionuclide activity by setting as a reference the most abundant element -Co-60 in the case of the Kozloduy NPP. The ratio η i of the mean annual permissible concentration in air for each radionuclide (RPC-92) to that of Co-60 is calculated. It is found that η i has the same or close values for groups of radionuclides, e.g. η i = 2.10 -4 for 238 Pu, 239 Pu, 240 Pu, 241 Am, 244 Cm; η i = 5 for 89 Sr, 91 Y; 93 Nb, 134 Cs, 137 Cs; η i = 50 for 55 Fe, 63 Ni, 95 Zr, 95 Nb, 140 Ba, 140 La. Then it is compared to the experimentally measured values of the same quantity η iexp , derived from surface contamination data. The ratio η iexp /η i is plotted against log η i . The resulting nomograms give graphic representation of the radiobiological significance of various radionuclide groups. Data from different locations at the Kozloduy NPP are presented. It is found that the alpha emitter contamination has highest values in the Unit 1 (WWER-440) control rooms after repair. The Unit 5 (WWER-1000) has lower alpha contamination compared to WWER-440 units. 1 ref., 5 figs., 1 tab

  2. The Mobile Surface Contamination Monitor II environmental radiological characterization utilizing GPS/GIS technologies

    International Nuclear Information System (INIS)

    Wendling, M.A.

    1993-05-01

    Time, cost, and most importantly quality of data are the three factors to measure the success of field radiological characterizations. The application of coupling radiation detection instrumentation to a GPS receiver has dramatically increased the data quality achievable compared to traditional environmental radiological survey methods. Improvements in verifying adequate spatial coverage of an area while collecting data and at,the same time reducing field time requirements can be realized. Data acquired during the recent implementation of the Mobile Surface Contamination Monitor 11 (MSCM-11) will be presented to demonstrate the advantages of this system over traditional radiological survey methods. The comparison will include time and manpower requirements. Linking the complimentary GPS, GIS and radiation detection technologies on a mobile tractor based platform has provided a tool to provide radiological characterization data faster, cheaper, and better to assist in the Environmental Restoration Mission of the Hanford Site

  3. Radioecological state of some surface water systems of contaminated areas of both Gomel and Mogilev Regions

    International Nuclear Information System (INIS)

    Datskevich, P. I.; Komissariv, F. D.; Khvale', O. D.; Basharina, L. P.; Lobach, I. L.

    1997-01-01

    The radioecological situation of different ecosystems of Belarus and their components has been analysed. Such components of the surface water ecosystems as water, suspensions, sediments and soils of water-collection areas were used for the investigation of the content of cesium 137 and strontium 90. The received data were given since 1990. The content of cesium 137 and strontium 90 in the components of water ecosystems was counted in the laboratory conditions by means of standard methods of beta radiometry, semiconductor gamma spectrometry and radiochemistry. The error of measurement of radioactivity was not higher than 25 and 35% for cesium 137 and strontium 90 accordingly. Water ecosystems were distinguished by the state of contamination of water-collection areas and hydrological parameters. These and some other reasons considered in the article influence on the character of cesium 137 and strontium 90 behaviour in water ecosystems

  4. Removal of Airborne Contaminants from a Surface Tank by a Push-Pull System

    DEFF Research Database (Denmark)

    Heiselberg, Per; Topp, Claus

    Open surface tanks are used in many industrial processes, and local exhaust systems are often designed to capture and remove toxic fumes diffused from materials in the tanks prior to their escape into the workplace environment. The push-pull system seems to be the most efficient local exhaust...... system, but proper design is required to ensure health and safety of the workers and, furthermore, it is very desirable from an energy conservation point of view to determine an optimum and -an efficient design of push-pull hoods which can exhaust all contaminants with a minimum quantity of volume flow....... The paper describes and discusses different design methods and compares designed values with results from a measurement series of push-pull system efficiency....

  5. The Development of a Sub-Surface Monitoring System for Organic Contamination in Soils and Groundwater

    Directory of Open Access Journals (Sweden)

    Sharon L. Huntley

    2002-01-01

    Full Text Available A major problem when dealing with environmental contamination is the early detection and subsequent surveillance of the contamination. This paper describes the potential of sub-surface sensor technology for the early detection of organic contaminants in contaminated soils, sediments, and landfill sites. Rugged, low-power hydrocarbon sensors have been developed, along with a data-logging system, for the early detection of phase hydrocarbons in soil. Through laboratory-based evaluation, the ability of this system to monitor organic contamination in water-based systems is being evaluated. When used in conjunction with specific immunoassays, this can provide a sensitive and low-cost solution for long-term monitoring and analysis, applicable to a wide range of field applications.

  6. Influence of temporary cement contamination on the surface free energy and dentine bond strength of self-adhesive cements.

    Science.gov (United States)

    Takimoto, Masayuki; Ishii, Ryo; Iino, Masayoshi; Shimizu, Yusuke; Tsujimoto, Akimasa; Takamizawa, Toshiki; Ando, Susumu; Miyazaki, Masashi

    2012-02-01

    The surface free energy and dentine bond strength of self-adhesive cements were examined after the removal of temporary cements. The labial dentine surfaces of bovine mandibular incisors were wet ground with #600-grit SiC paper. Acrylic resin blocks were luted to the prepared dentine surfaces using HY Bond Temporary Cement Hard (HY), IP Temp Cement (IP), Fuji TEMP (FT) or Freegenol Temporary Cement (TC), and stored for 1 week. After removal of the temporary cements with an ultrasonic tip, the contact angle values of five specimens per test group were determined for the three test liquids, and the surface-energy parameters of the dentine surfaces were calculated. The dentine bond strengths of the self-adhesive cements were measured after removal of the temporary cements in a shear mode at a crosshead speed of 1.0mm/min. The data were subjected to one-way analysis of variance (ANOVA) followed by Tukey's HSD test. For all surfaces, the value of the estimated surface tension component γ(S)(d) (dispersion) was relatively constant at 41.7-43.3 mJm(-2). After removal of the temporary cements, the value of the γ(S)(h) (hydrogen-bonding) component decreased, particularly with FT and TC. The dentine bond strength of the self-adhesive cements was significantly higher for those without temporary cement contamination (8.2-10.6 MPa) than for those with temporary cement contamination (4.3-7.1 MPa). The γ(S) values decreased due to the decrease of γ(S)(h) values for the temporary cement-contaminated dentine. Contamination with temporary cements led to lower dentine bond strength. The presence of temporary cement interferes with the bonding performance of self-adhesive cements to dentine. Care should be taken in the methods of removal of temporary cement when using self-adhesive cements. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. What Orthopaedic Operating Room Surfaces Are Contaminated With Bioburden? A Study Using the ATP Bioluminescence Assay.

    Science.gov (United States)

    Richard, Raveesh Daniel; Bowen, Thomas R

    2017-07-01

    Contaminated operating room surfaces can increase the risk of orthopaedic infections, particularly after procedures in which hardware implantation and instrumentation are used. The question arises as to how surgeons can measure surface cleanliness to detect increased levels of bioburden. This study aims to highlight the utility of adenosine triphosphate (ATP) bioluminescence technology as a novel technique in detecting the degree of contamination within the sterile operating room environment. What orthopaedic operating room surfaces are contaminated with bioburden? When energy is required for cellular work, ATP breaks down into adenosine biphosphate (ADP) and phosphate (P) and in that process releases energy. This process is inherent to all living things and can be detected as light emission with the use of bioluminescence assays. On a given day, six different orthopaedic surgery operating rooms (two adult reconstruction, two trauma, two spine) were tested before surgery with an ATP bioluminescence assay kit. All of the cases were considered clean surgery without infection, and this included the previously performed cases in each sampled room. These rooms had been cleaned and prepped for surgery but the patients had not been physically brought into the room. A total of 13 different surfaces were sampled once in each room: the operating room (OR) preparation table (both pre- and postdraping), OR light handles, Bovie machine buttons, supply closet countertops, the inside of the Bair Hugger™ hose, Bair Hugger™ buttons, right side of the OR table headboard, tourniquet machine buttons, the Clark-socket attachment, and patient positioners used for total hip and spine positioning. The relative light units (RLUs) obtained from each sample were recorded and data were compiled and averaged for analysis. These values were compared with previously published ATP benchmark values of 250 to 500 RLUs to define cleanliness in both the hospital and restaurant industries. All

  8. The influence of surface contamination on the ion emission from nanosecond-pulsed laser ablation of Al and Cu

    Science.gov (United States)

    Ullah, S.; Dogar, A. H.; Qayyum, H.; Rehman, Z. U.; Qayyum, A.

    2018-04-01

    Ions emitted from planar Al and Cu targets irradiated with a 1064 nm pulsed laser were investigated with the help of a time-resolving Langmuir probe. It was found that the intensity of the ions emitted from a target area rapidly decreases with the increasing number of laser shots, and seems to reach saturation after about 10 laser shots. The saturated intensity of Al and Cu ions was approximately 0.1 and 0.3 times the intensity of the respective ions measured at the first laser shot, respectively. The higher target ion intensity for the first few shots is thought to be due to the enhanced ionization of target atoms by vacuum-ultraviolet radiations emitted from the thermally excited/ionized surface contaminants. The reduction of target ion intensity with an increasing number of laser shots thus indicates the removal of contaminants from the irradiated surface area. Laser-cleaned Al and Cu surfaces were then allowed to be recontaminated with residual vacuum gases and the ion intensity was measured at various time delays. The prolonged exposure of the cleaned target to vacuum residual gases completely restores the ion intensity. Regarding surface contaminants removal, laser shots of higher intensities were found to be more effective than a higher number of laser shots having lower intensities.

  9. Emerging organic contaminants in surface water and groundwater: a first overview of the situation in Italy.

    Science.gov (United States)

    Meffe, Raffaella; de Bustamante, Irene

    2014-05-15

    This paper provides the first review of the occurrence of 161 emerging organic compounds (EOCs) in Italian surface water and groundwater. The reported EOCs belong to the groups of industrials, pharmaceuticals, estrogens and illicit drugs. Occurrence of 137 pesticides was also reported. The reviewed research works have been published between 1997 and 2013. The majority of the studies have been carried out in Northern Italy (n. 30) and to a lower extent in Central Italy (n. 13). Only a limited number of research studies report EOC concentrations in water resources of Southern Italy. The EOCs that have been more frequently studied are in the following descending order, pesticides (16), pharmaceuticals (15), industrials (13), estrogens (7) and illicit drugs (2). Research activities investigating the EOC occurrence in surface water are more numerous than those in groundwater. This is consistent with the higher complexity involved in groundwater sampling and EOC detection. Among the reported EOCs, industrials and pesticides are those occurring in both surface water and groundwater with the highest concentrations (up to 15 × 10(6) and 4.78 × 0(5)ng L(-1), respectively). Concentrations of pharmaceuticals in surface water reach a maximum of 3.59 × 10(3)ng L(-1), whereas only the antimicrobial agent josamycin has been encountered in groundwater with a concentration higher than 100 ng L(-1). Both estrogens and illicit drugs appeared in surface water with concentrations lower than 50 ng L(-1). Groundwater concentrations for estrogens were measured to be below the detection limits, whereas illicit drugs have so far not been studied in groundwater. The present review reveals the serious contamination status of Italian surface water and groundwater especially by pesticides, industrials and to a lower extent by pharmaceuticals and the necessity to foster the research on EOC occurrence in Italian water resources, in particular in Southern Italy where a limited number of

  10. General radioactive contamination of the biosphere measurements in the Netherlands 1974. Annual report Coordination Commission radioactivity measurements and Coordination Commission for the measurements of radioactivity and xenobiotic materials

    Energy Technology Data Exchange (ETDEWEB)

    1975-07-01

    For several years, measurements have been performed in the Netherlands to determine radioactive contamination of the biosphere. These measurements are carried out by various institutes responsible to three ministries: the Ministery of 'Health and Environmental Protection', of 'Agriculture and Fisheries' and of 'Transport and Water', (Dutch: 'Verkeer en Waterstaat', under the supervision of the Coordination Commission Radioactive Measurements (CCRA)). Besides radionuclides, many other elements and compounds are considered harmful for man, animal and the environment. A systematic control of the extent of the contamination of the biosphere, in the same way as is in operation for radionuclides, has been proposed for a number of the most harmful contaminants of the biosphere. The measurements are divided into measurements for the National Measuring Programme and additional Measurements. The former include the analyses essential for an efficacious control of the radioactivity of the biosphere. Measurements are performed in air, soil, surface water, milk and in deposition on the surface of the earth. Besides the determination of the usual radionuclides, as performed up to 1970, deposited radioactivity and surface water are also tested for some other specific radionuclides which may be set free at nuclear installations. Finally, samples of milk and grass from the surroundings of nuclear reactors and water from drinking-waterreservoirs have been analysed. Results are given of determination of tritium in drinking water of four big cities, and of radionuclides in some fishery products from the Dutch coastal waters in view of the potential of some marine organisms to concentrate fission products and especially activated corrosion products from nuclear installations. Adiitionally are given the results of measurements by the licensees of the Dutch nuclear installations of samples from the surroundings of their plants.

  11. Development of floor smear sampler (floor radioactive contamination measuring instrument) for nuclear facilities

    International Nuclear Information System (INIS)

    Miyagawa, Minoru; Ito, Haruo; Nozawa, Katsuro; Shinohara, Yotaro; Hashimoto, Hiroshi.

    1980-01-01

    The control of the floor contamination with radioactive substances in nuclear facilities is strictly carried out by smear method, in which the contaminants on floor surfaces are wiped off with filter papers or cloths, and the contamination density on the floor surfaces is measured through their intensity of radioactivity. This wiping work is laborious since it is carried out in leaning-over posture when many samples must be taken in wide floor area. Therefore, to achieve labor saving in this work, an automatic sampler was developed. In the floor smear sampler developed, samples are taken on long band type wiping cloths only by handle operation, and the sample numbers are printed. When many samples are taken in wide floor area, this is especially effective, and the labor saving by 1/3 to 1/2 can be achieved. At present, this sampler is put in practical use in Hamaoka Nuclear Power Station. At the time of trial manufacture, the method of wiping, the mechanisms of wiping, cloth feeding and running, the contact pressure and the number of times of wiping affecting wiping efficiency and the required torque of a motor were examined. The developed sampler is that of constant contact pressure, vibration wiping type, and the rate of sampling is 10 sec per one sample. 100 samples can be taken on one roll of wiping cloth. The results of performance test are reported. (Kako, I.)

  12. Direct measurement of homogeneously distributed radioactive air contamination with germanium detectors

    International Nuclear Information System (INIS)

    Sowa, W.

    1990-01-01

    Air contamination by γ emitting radionuclides was measured with a vertically arranged germanium detector, laterally shielded by a lead ring, and calibration factors and detection limits of a number of fission products determined. The possibility of measuring simultaneously existing air and soil contamination by measurements with and without lead shield is described. The change of detection limit of air contamination is presented for different soil contamination levels by the same radionuclide. Calibration factors are given to determine the dose rate on the ground due to air contamination by different radionuclides. (author)

  13. Surface sterilization method for reducing microbial contamination of ...

    African Journals Online (AJOL)

    An effective disinfection method for strawberry (Fragaria x ananassa Duch.) cv. Senga Sengana micropropagation using runner tips and nodal segments as explants was developed. The explants were surface sterilized with different sterilants for different durations. The present studies on the effect of different regimes of ...

  14. Water Quality, Mitigation Measures of Arsenic Contamination and Sustainable Rural Water Supply Options in Bangladesh

    Directory of Open Access Journals (Sweden)

    HOSSAIN M. ANAWAR

    2012-06-01

    Full Text Available Arsenic contamination of groundwater has created a serious public health issue in Bangladesh and West Bengal (India, because groundwater is widely used for drinking, household and agriculture purposes. Given the magnitude of the problem of groundwater contamination facing Bangladesh, effective, acceptable and sustainable solutions are urgently required. Different NGOs (Non-government organizations and research organizations are using their extensive rural networks to raise awareness and conduct pilot projects. The implication of the results from the previous studies is robust, but coastly arsenic reduction technologies such as activated alumina technology, and As and Fe removal filters may find little social acceptance, unless heavily subsidized. This review paper analysed the quality of surface water and ground water, all mitigation measures and the most acceptable options to provide sustainable access to safe- water supply in the rural ares of Bangladesh. Although there are abundant and different sources of surface water, they can not be used for drinking and hosehold purposes due to lack of sanitation, high faecal coliform concentration, turibidity and deterioration of quality of surface water sources. There are a few safe surface water options; and also there are several methods available for removal of arsenic and iron from groundwater in large conventional treatments plants. This review paper presented a short description of the currently available and most sustainable technologies for arsenic and iron removal, and alternative water supply options in the rural areas.

  15. use of the RESRAD-BUILD code to calculate building surface contamination limits

    International Nuclear Information System (INIS)

    Faillace, E.R.; LePoire, D.; Yu, C.

    1996-01-01

    Surface contamination limits in buildings were calculated for 226 Ra, 230 Th, 232 Th, and natural uranium on the basis of 1 mSv y -1 (100 mrem y -1 ) dose limit. The RESRAD-BUILD computer code was used to calculate these limits for two scenarios: building occupancy and building renovation. RESRAD-BUILD is a pathway analysis model designed to evaluate the potential radiological dose incurred by individuals working or living inside a building contaminated with radioactive material. Six exposure pathways are considered in the RESRAD-BUILD code: (1) external exposure directly from the source; (2) external exposure from materials deposited on the floor; (3) external exposure due to air submersion; (4) inhalation of airborne radioactive particles; (5) inhalation of aerosol indoor radon progeny; and (6) inadvertent ingestion of radioactive material, either directly from the sources or from materials deposited on the surfaces. The code models point, line, area, and volume sources and calculates the effects of radiation shielding, building ventilation, and ingrowth of radioactive decay products. A sensitivity analysis was performed to determine how variations in input parameters would affect the surface contamination limits. In most cases considered, inhalation of airborne radioactive particles was the primary exposure pathway. However, the direct external exposure contribution from surfaces contaminated with 226 Ra was in some cases the dominant pathway for building occupancy depending on the room size, ventilation rates, and surface release fractions. The surface contamination limits are most restrictive for 232 Th, followed by 230 Th, natural uranium, and 226 Ra. The results are compared with the surface contamination limits in the Nuclear Regulatory Commission's Regulatory Guide 1.86, which are most restrictive for 226 Ra and 230 Th, followed by 232 Th, and are least restrictive for natural uranium

  16. The development of the American national standard, ''control of radioactive surface contamination on materials, equipment and facilities to be released for uncontrolled use''

    International Nuclear Information System (INIS)

    Shapiro, J.

    1980-01-01

    The American National Standard, Control of Radioactive Surface Contamination on Materials, Equipment and Facilities to be Released for Uncontrolled Use, was developed under the procedures of ANSI for ANSI Main Committee N13 (Radiation Protection) by a working group of the Health Physics Society Standards Committee. This standard provides criteria for the control of materials, equipment and facilities contaminated with radioactivity proposed to be released for uncontrolled use. Permissible contamination limits are specified as well as methods assessing the levels of contamination. This paper reviews the proceedings of the Subcommittee on Radioactive Surface Contamination, the comments received by reviewers of the standard, the resolution of the committee, and the bases for reaching the final limits, recommendations, and measurement procedures. (H.K.)

  17. Sound field separation with cross measurement surfaces.

    Directory of Open Access Journals (Sweden)

    Jin Mao

    Full Text Available With conventional near-field acoustical holography, it is impossible to identify sound pressure when the coherent sound sources are located on the same side of the array. This paper proposes a solution, using cross measurement surfaces to separate the sources based on the equivalent source method. Each equivalent source surface is built in the center of the corresponding original source with a spherical surface. According to the different transfer matrices between equivalent sources and points on holographic surfaces, the weighting of each equivalent source from coherent sources can be obtained. Numerical and experimental studies have been performed to test the method. For the sound pressure including noise after separation in the experiment, the calculation accuracy can be improved by reconstructing the pressure with Tikhonov regularization and the L-curve method. On the whole, a single source can be effectively separated from coherent sources using cross measurement.

  18. Tritium activity balance in hairless rats following skin-contact exposure to tritium-gas-contaminated stainless-steel surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Trivedi, A

    1994-06-01

    Studies using animals and human volunteers have demonstrated that the dosimetry for skin-contact exposure to contaminated metal surfaces differs from that for the intake of tritiated water or tritium gas. However, despite the availability of some information on the dosimetry for skin-contact with tritium-gas-contaminated metal surfaces, uncertainties in estimating skin doses remain, because of poor accounting for the applied tritium activity in the body (Eakins et al., 1975; Trivedi, 1993). Experiments on hairless rats were performed to account for the tritium activity applied onto the skin. Hairless rats were contaminated through skin-contact exposure to tritium-gas-contaminated stainless-steel planchets. The activity in the first smear was about 35% of the total removable activity (measured by summing ten consecutive swipes). The amount of tritium applied onto the skin can be approximated by estimating the tritium activity in the first smear removed form the contaminated surfaces. 87 {+-} 9% of the transferred tritium was retained in the exposed skin 30 min post-exposure. 30 min post exposure, the unexposed skin and the carcass retained 8 {+-} 6% and 3 {+-} 2% of the total applied tritium activity, respectively. The percentage of tritium evolved from the body or breathed out was estimated to be 2 {+-} 1% of the total applied activity 30 min post-exposure. It is recommended that to evaluate accurately the amount of tritium transferred to the skin, alternative measurement approaches are required that can directly account for the transferred activity onto the skin. 15 refs., 13 tabs., 7 figs.

  19. Surface sediment quality relative to port activities: A contaminant-spectrum assessment.

    Science.gov (United States)

    Yu, Shen; Hong, Bing; Ma, Jun; Chen, Yongshan; Xi, Xiuping; Gao, Jingbo; Hu, Xiuqin; Xu, Xiangrong; Sun, Yuxin

    2017-10-15

    Ports are facing increasing environmental concerns with their importance to the global economy. Numerous studies indicated sediment quality deterioration in ports; however, the deterioration is not discriminated for each port activity. This study investigated a spectrum of contaminants (metals and organic pollutants) in surface sediments at 20 sampling points in Port Ningbo, China, one of the top five world ports by volume. The spectrum of contaminants (metals and organic pollutants) was quantified following marine sediment quality guidelines of China and USA and surface sediment quality was assessed according to thresholds of the two guidelines. Coupling a categorical matrix of port activities with the matrix of sedimentary contaminants revealed that contaminants were highly associated with the port operations. Ship repair posed a severe chemical risk to sediment. Operations of crude oil and coal loadings were two top activities related to organic pollutants in sediments while port operations of ore and container loadings discharged metals. Among the 20 sampling points, Cu, Zn, Pb, and DDT and its metabolites were the priority contaminants influencing sediment quality. Overall, surface sediments in Port Ningbo had relatively low environmental risks but ship repair is an environmental concern that must be addressed. This study provides a practical approach for port activity-related quality assessment of surface sediments in ports that could be applicable in many world sites. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Improving Satellite Retrieved Infrared Sea Surface Temperatures in Aerosol-Contaminated Regions

    Science.gov (United States)

    Luo, B.; Minnett, P. J.; Szczodrak, G.; Kilpatrick, K. A.

    2017-12-01

    Infrared satellite observations of sea surface temperature (SST) have become essential for many applications in meteorology, climatology, and oceanography. Applications often require high accuracy SST data: for climate research and monitoring an absolute uncertainty of 0.1K and stability of better than 0.04K per decade are required. Tropospheric aerosol concentrations increase infrared signal attenuation and prevent the retrieval of accurate satellite SST. We compare satellite-derived skin SST with measurements from the Marine-Atmospheric Emitted Radiance Interferometer (M-AERI) deployed on ships during the Aerosols and Ocean Science Expeditions (AEROSE) and with quality-controlled drifter temperatures. After match-up with in-situ SST and filtering of cloud contaminated data, the results indicate that SST retrieved from MODIS (Moderate Resolution Imaging Spectroradiometer) aboard the Terra and Aqua satellites have negative (cool) biases compared to shipboard radiometric measurements. There is also a pronounced negative bias in the Saharan outflow area that can introduce SST errors >1 K at aerosol optical depths > 0.5. In this study, we present a new method to derive night-time Saharan Dust Index (SDI) algorithms based on simulated brightness temperatures at infrared wavelengths of 3.9, 10.8 and 12.0 μm, derived using RTTOV. We derived correction coefficients for Aqua MODIS measurements by regression of the SST errors against the SDI. The biases and standard deviations are reduced by 0.25K and 0.19K after the SDI correction. The goal of this study is to understand better the characteristics and physical mechanisms of aerosol effects on satellite retrieved infrared SST, as well as to derive empirical formulae for improved accuracies in aerosol-contaminated regions.

  1. Cuantificación de la contaminación del gas de protección en procesos de soldadura con arco eléctrico por medio de mediciones de oxígeno en la superficie del material base Quantification of contamination of the shielding gas in arc welding processes through measurement of oxygen on the surface of the base material

    Directory of Open Access Journals (Sweden)

    Julio Fuentes-Muñoz

    2012-09-01

    Full Text Available A metodologia apresentada neste trabalho se baseia em medições do teor de oxigênio na superfície do metal base, possibilitando assim, uma avaliação quantitativa da contaminação do gás de proteção. Os gases utilizados nos processos de soldagem definem as características do arco e protegem a poça de soldagem. A contaminação do gás, por exemplo, com o ar do meio ambiente, prejudica as propriedades da união soldada. A contaminação do gás de proteção não é somente dependente da qualidade do gás utilizado, como também tem que ser considerado os componentes contidos na tocha. Até agora, o nível da contaminação do gás produzido pela tocha tem sido analisado somente de forma empírica, avaliando a qualidade e forma do cordão de solda. A medição do oxigênio na superfície do metal de base é um método simples e preciso para analisar o nível de contaminação do gás de proteção. Este procedimento permite uma avaliação quantitativa, inclusive na presença do arco. No contexto deste trabalho se apresentará por meio de exemplos em tochas TIG e MIG/MAG as possibilidades da utilização desta metodologia para o desenvolvimento e análise de processos de soldagem a arco.The method presented in this paper is based on the measurement of oxygen on the surface of the base metal to enable a quantitative assessment of the contamination in the shielding gas. The gas used in arc processes affected arc properties and simultaneously protected the welding pool. The contamination of the shielding gases, e.g. with atmospheric air, damages the properties of the weld joint. The contamination in the shielding gas is not only dependent on the purity of the utilized gas, but also on the components of the welding torch. The level of contamination in the gas produced by the torch had been analyzed so far only by empirical evaluation of the quality and appearance of the welding seam. The measurement of oxygen on the surface of the base

  2. Spectral induced polarization (SIP) measurement of NAPL contaminated soils

    Science.gov (United States)

    Schwartz, N.; Huisman, J. A.; Furman, A.

    2010-12-01

    The potential applicability of spectral induce polarization (SIP) as a tool to map NAPLs (non aqueous phase liquids) contaminants at the subsurface lead researchers to investigate the electric signature of those contaminant on the spectral response. However, and despite the cumulative efforts, the effect of NAPL on the electrical properties of soil, and the mechanisms that control this effect are largely unknown. In this work a novel experiment is designed to further examine the effect of NAPL on the electrical properties of partially saturated soil. The measurement system that used is the ZEL-SIP04 impedance meter developed at the Forschungszentrum Julich, Germany. The system accurately (nominal phase precision of 0.1 mrad below 1 kHz) measures the phase and the amplitude of a material possessing a very low polarization (such as soil). The sample holder has a dimension of 60 cm long and 4.6 cm in diameter. Current and potential electrodes were made of brass, and while the current electrodes were inserted in full into the soil, the contact between the potential electrode and the soil was made through an Agarose bridge. Two types of soils were used: clean quartz sand, and a mixture of sand with clean Bentonite. Each soil (sandy or clayey) was mixed with water to get saturation degree of 30%. Following the mixture with water, NAPL was added and the composite were mixed again. Packing was done by adding and compressing small portions of the soil to the column. A triplicate of each mixture was made with a good reproducible bulk density. Both for the sandy and clayey soils, the results indicate that additions of NAPL decrease the real part of the complex resistivity. Additionally, for the sandy soil this process is time depended, and that a further decrease in resistivity develops over time. The results are analyzed considering geometrical factors: while the NAPL is electrically insulator, addition of NAPL to the soil is expected to increase the connectivity of the

  3. Evaluation of the homogeneity of reference flat sources used in calibration of surface contamination monitors

    International Nuclear Information System (INIS)

    Silva Junior, I.A.; Xavier, M.; Siqueira, P.T.D.; Potiens, M.P.A.

    2014-01-01

    The aim of this study was to re-evaluate the uniformity of the wide area reference sources of the Calibration Laboratory of Instruments (LCI-IPEN) used in the calibration of surface contamination monitors, according the recommendations of the ISO 8769 standard and the NRPB. In this work used six wide area reference sources of 150 cm 2 of 241 Am, 14 C, 36 Cl, 137 Cs, 90 Sr+ 90 Y and 99 Tc with reference dates between 1996 and 1997 and three sources of 100 cm 2 of 14 C, 137 Cs and 60 Co were used with reference dates 2007. Measurements were performed with a radiation monitor of the Thermo, model FH40GX with a pancake probe, model FHZ732GM. We also made several models on paper with the objective of define each measurement position and an aluminum plate with a square hole (6.25 cm 2 ) in its center, allowing the passage of the radiation only through the hole. Each wide area reference source was positioned in setup and measurements were performed in order to cover the entire surface of the source. The values of the uniformity obtained partially confirm previous data obtained in another study conducted by LCI-IPEN, showing that some wide area reference sources 150 cm 2 in disagree with ISO 8769. In the former work, just the source of 241 Am (7.3%) was within the range specified by the standard, now have sources of 241 Am (5.7%), 137 Cs (8.8%), 90 Sr+ 9 '0Y (8, 8%) and 99 Tc (9.2%) with values within the specified uniformity. The sources of 14 C (53.3%) and 36 Cl (16.6%) were outside the specified. The wide area reference sources of 100 cm 2 , show disagreement in values of uniformity of the sources 14 C (46.7%) and 60 Co (10.4%). The values of the uniformity of the wide area reference sources show that some fonts can not be used in calibrations, because not in accordance with the value of uniformity specified in ISO 8769:2010, this is a conditions to believe a laboratory according to ISO 17025, show the laboratory performs its services with a high quality. The

  4. Second IRMF comparison of surface contamination monitor calibrations 2001-2002

    CERN Document Server

    Scott, C J

    2002-01-01

    The Ionising Radiations Metrology Forum (IRMF) organised a second comparison of surface contamination monitor calibrations in which twenty establishments in the UK participated. The exercise involved the circulation of three surface contamination monitors for calibration using large area reference sources available in the participants' laboratories. The instruments used were a Mini Instruments EP15, a Berthold LB122 and an Electra ratemeter with DP6AD probe. The instrument responses were calculated by the individual participants and submitted to the for analysis along with details of the reference sources used. Details of the estimated uncertainties were also reported. The results are compared and demonstrate generally satisfactory agreement between the participating establishments.

  5. Effect of surface contaminants on the light emission spectrum of LiF TLDs

    International Nuclear Information System (INIS)

    Abhold, M.E.

    1987-01-01

    Recent results show the differences between the light emissions spectra from LiF Thermoluminescent Dosimeters (TLDs) for gamma vs. alpha irradiations to be due to contaminants on the surface of the TLD. The light emission spectrum for thermal neutron irradiations was observed to be identical to that for a Cs-137 gamma irradiation in Harshaw TLD-100. Further experiments with surface treatments on TLD-100 indicate trace contaminants introduced by the standard methanol cleansing rinse in reagent grade methanol to have a substantial effect on the light emission spectrum for Am-241 alpha irradiations

  6. Surface contamination effects on leaf chemical composition in the Atlantic Forest

    International Nuclear Information System (INIS)

    Ferrari, A.A.; Franca, E.J.; Fernandes, E.A.N.; Bacchi, M.A.

    2006-01-01

    The exogenous material that adheres to the leaf surface affects the elemental composition of the plant itself, thereby constituting one of the major error sources in plant analysis. The present work investigated the surface contamination of leaves from the Atlantic Forest. Instrumental neutron activation analysis (INAA) was applied to assess the efficiency of leaf EDTA-washing. Chemical element concentrations were corrected using Sc (soil tracer) since resuspended soil is the main source of contamination in leaves. As a result, EDTA-washing should be used mainly for the evaluation of terrigenous elements, while the Sc-corrected concentrations are considered satisfactory for the other elements. (author)

  7. Chemometric Analysis of Selected Organic Contaminants in Surface Water of Langat River Basin

    International Nuclear Information System (INIS)

    Mohamad Rafaie Mohamed Zubir; Rozita Osman; Norashikin Saim

    2016-01-01

    Chemometric techniques namely hierarchical agglomerative cluster analysis (HACA), discriminant analysis (DA), principal component analysis (PCA) and factor analysis (FA) were applied to the distribution of selected organic contaminants (polycyclic aromatic hydrocarbons (PAHs), sterols, pesticides (chloropyrifos), and phenol) to assess the potential of using these organic contaminants as chemical markers in Langat River Basin. Water samples were collected from February 2012 to January 2013 on a monthly basis for nine monitoring sites along Langat River Basin. HACA was able to classify the sampling sites into three clusters which can be correlated to the level of contamination (low, moderate and high contamination sites). DA was used to discriminate the sources of contamination using the selected organic contaminants and relate to the existing DOE local activities groupings. Forward and backward stepwise DA was able to discriminate two and five organic contaminants variables, respectively, from the original 13 selected variables. The five significant variables identified using backward stepwise DA were fluorene, pyrene, stigmastanol, stigmasterol and phenol. PCA and FA (varimax functionality) were used to identify the possible sources of each organic contaminant based on the inventory of local activities. Five principal components were obtained with 66.5 % of the total variation. Result from FA indicated that PAHs (pyrene, fluorene, acenaphthene, benzo[a]anthracene) originated from industrial activity and socio-economic activities; while sterols (coprostanol, stigmastanol and stigmasterol) were associated to domestic sewage and local socio-economic activities. The occurrence of chloropyrifos was correlated to agricultural activities, urban and domestic discharges. This study showed that the application of chemometrics on the distribution of selected organic contaminants was able to trace the sources of contamination in surface water. (author)

  8. [Disinfectants and main sanitary and preventive measures for protection of ventilation and air-conditioning systems from Legionella contamination].

    Science.gov (United States)

    Gerasimov, V N; Golov, E A; Khramov, M V; Diatlov, I A

    2008-01-01

    The study was devoted to selection and assessment of disinfecting preparations for prevention of contamination by Legionella. Using system of criteria for quality assessment of disinfectants, seven newdomestic ones belonging to quaternary ammonium compounds class or to oxygen-containing preparations and designed for disinfecting of air-conditioning and ventilation systems were selected. Antibacterial and disinfecting activities of working solutions of disinfectants were tested in laboratory on the test-surfaces and test-objects of premises' air-conditioning and ventilation systems contaminated with Legionella. High antimicrobial and disinfecting activity of new preparations "Dezactiv-M", "ExtraDez", "Emital-Garant", "Aquasept Plus", "Samarovka", "Freesept", and "Ecobreeze Oxy" during their exposure on objects and materials contaminated with Legionella was shown. Main sanitary and preventive measures for defending of air-conditioning and ventilation systems from contamination by Legionella species were presented.

  9. Atmospheric-Pressure Plasma Cleaning of Contaminated Surfaces

    International Nuclear Information System (INIS)

    Hicks, Robert F.; Selwyn, Gary S.

    2001-01-01

    Project was to develop a low-cost, environmentally benign technology for the decontamination and decommissioning of transuranic waste. With the invention of the atmospheric-pressure plasma jet the goal was achieved. This device selectively etches heavy metals from surfaces, rendering objects radiation free and suitable for decommissioning. The volatile reaction products are captured on filters, which yields a tremendous reduction in the volume of the waste. Studies on tantalum, a surrogate material for plutonium, have shown that etch rate of 6.0 microns per minute can be achieved under mild conditions. Over the past three years, we have made numerous improvements in the design of the plasma jet. It may now be operated for hundreds of hours and not undergo any degradation in performance. Furthermore, small compact units have been developed, which are easily deployed in the field

  10. Force control of a robot for surface contamination detection

    International Nuclear Information System (INIS)

    Petterson, B.J.; Jones, J.F.

    1987-01-01

    A system is under development at Sandia National Laboratories for use in understanding the issues relating to automated robotic handling of spent nuclear fuel shipping casks. The goal of robotic handling is reduction of personnel radiation exposure at the proposed geologic repositories. One of the major technology development areas has been the integration of sensors into the control of the robot system to allow operation in semi-structured environments. In particular, a multiaxis force sensor is used to make robot trajectory corrections based on the contact force between the robot and workpiece. This force feedback system allows contact swipes (smears) to be made on the cask surface in a repeatable manner. 8 refs., 3 figs

  11. Atmospheric-Pressure Plasma Cleaning of Contaminated Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Robert F. Hicks; Gary S. Selwyn

    2001-01-09

    Project was to develop a low-cost, environmentally benign technology for the decontamination and decommissioning of transuranic waste. With the invention of the atmospheric-pressure plasma jet the goal was achieved. This device selectively etches heavy metals from surfaces, rendering objects radiation free and suitable for decommissioning. The volatile reaction products are captured on filters, which yields a tremendous reduction in the volume of the waste. Studies on tantalum, a surrogate material for plutonium, have shown that etch rate of 6.0 microns per minute can be achieved under mild conditions. Over the past three years, we have made numerous improvements in the design of the plasma jet. It may now be operated for hundreds of hours and not undergo any degradation in performance. Furthermore, small compact units have been developed, which are easily deployed in the field.

  12. Contamination analysis unit

    International Nuclear Information System (INIS)

    Gregg, H.R.; Meltzer, M.P.

    1996-01-01

    The portable Contamination Analysis Unit (CAU) measures trace quantities of surface contamination in real time. The detector head of the portable contamination analysis unit has an opening with an O-ring seal, one or more vacuum valves and a small mass spectrometer. With the valve closed, the mass spectrometer is evacuated with one or more pumps. The O-ring seal is placed against a surface to be tested and the vacuum valve is opened. Data is collected from the mass spectrometer and a portable computer provides contamination analysis. The CAU can be used to decontaminate and decommission hazardous and radioactive surfaces by measuring residual hazardous surface contamination, such as tritium and trace organics. It provides surface contamination data for research and development applications as well as real-time process control feedback for industrial cleaning operations and can be used to determine the readiness of a surface to accept bonding or coatings. 1 fig

  13. Surface resistivity measurement of plasma treated polymers

    International Nuclear Information System (INIS)

    Simon, D.; Pigram, P.J.; Liesegang, J.

    2000-01-01

    Full text: Resistivity of insulators is an important property of materials used within the integrated circuit and packaging industries. The measurement of electrical resistivity of insulator materials in the surface region in this work is interpreted through observations of surface charge decay. A self-field driven and diffusion charge transport theory is used to model the process and resistivity values obtained computationally. Data for the charge decay of surface charged samples are collected by suspending them inside a coaxial cylinder connected to an electrometer. Samples used have been low density polyethylene LDPE sheet, both pristine and surface treated. Some samples have been treated by air plasma at low vacuum pressures for different periods of time; others have been washed in ethyl acetate and then plasma treated before the resistivity measurement. The sets of resistivity measurements form the various treatments are compared below. X-ray photoelectron spectroscopy (XPS) has also been used to investigate and account for the observed variations in surface resistivity

  14. Global occurrence of anti-infectives in contaminated surface waters: Impact of income inequality between countries.

    Science.gov (United States)

    Segura, Pedro A; Takada, Hideshige; Correa, José A; El Saadi, Karim; Koike, Tatsuya; Onwona-Agyeman, Siaw; Ofosu-Anim, John; Sabi, Edward Benjamin; Wasonga, Oliver V; Mghalu, Joseph M; dos Santos Junior, Antonio Manuel; Newman, Brent; Weerts, Steven; Yargeau, Viviane

    2015-07-01

    The presence anti-infectives in environmental waters is of interest because of their potential role in the dissemination of anti-infective resistance in bacteria and other harmful effects on non-target species such as algae and shellfish. Since no information on global trends regarding the contamination caused by these bioactive substances is yet available, we decided to investigate the impact of income inequality between countries on the occurrence of anti-infectives in surface waters. In order to perform such study, we gathered concentration values reported in the peer-reviewed literature between 1998 and 2014 and built a database. To fill the gap of knowledge on occurrence of anti-infectives in African countries, we also collected 61 surface water samples from Ghana, Kenya, Mozambique and South Africa, and measured concentrations of 19 anti-infectives. A mixed one-way analysis of covariance (ANCOVA) model, followed by Turkey-Kramer post hoc tests was used to identify potential differences in anti-infective occurrence between countries grouped by income level (high, upper-middle and lower-middle and low income) according to the classification by the World Bank. Comparison of occurrence of anti-infectives according to income level revealed that concentrations of these substances in contaminated surface waters were significantly higher in low and lower-middle income countries (p=0.0001) but not in upper-middle income countries (p=0.0515) compared to high-income countries. We explained these results as the consequence of the absence of or limited sewage treatment performed in lower income countries. Furthermore, comparison of concentrations of low cost anti-infectives (sulfonamides and trimethoprim) and the more expensive macrolides between income groups suggest that the cost of these substances may have an impact on their environmental occurrence in lower income countries. Since wastewaters are the most important source of contamination of anti-infectives and other

  15. Derived surface contamination limits for the uranium mining and milling industry

    International Nuclear Information System (INIS)

    Ching, S.H.

    1984-10-01

    Derived Surface Contamination Limits (DSCL) are proposed for the control of surface contamination at the work place for the uranium mining and milling industry. They have been derived by a method incorporating recent ICRP recommendations and consideration of the radiation exposure pathways of ingestion, inhalation and external irradiation of the basal layer of skin. A generalized DSCL of 10 5 Bq/m 2 of beta activity is recommended for all contaminants likely to be found in uranium mine and mill workplaces except for fresh uranium concentrates. In the latter case, the DSCL is expressed in terms of alpha activity because the ratio of beta to alpha activities for fresh uranium concentrates is variable; the beta activity increases with the ingrowth of U-238 daughter products (Th-234 and Pa-234m) until secular equilibrium is re-established in about six months. A surface contamination limit of 10 4 Bq/m 2 of beta activity is proposed for the release of non-porous materials and equipment with no detectable loose contamination to the public domain

  16. Concentration and toxicity of sea-surface contaminants in Puget Sound

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, J.T.; Crecelius, E.A.; Kocan, R.

    1986-04-01

    The Marine Research Laboratory conducted studies during CY 1985 to evaluate the effects of sea-surface contamination on the reproductive success of a valued marine species. Microlayer and bulk water samples were collected from a rural bay, central Puget Sound, and three urban bays and analyzed for a number of metal and organic contaminants as well as for densities of neuston and plankton organisms. Fertilized neustonic eggs of sand sole (Psettichthys melanostictus) were exposed to the same microlayer samples during their first week of embryonic and larval development. Also, we evaluated the effects of microlayer extracts on the growth of trout cell cultures. Compared to rural sites, urban bays generally contained lower densities of neustonic flatfish eggs during the spawning season. Also, in contrast to the rural sites or the one central Puget Sound site, approximately half of the urban bay microlayer samples resulted in significant increases in embryo mortality (up to 100%), kyphosis (bent spine abnormalities) in hatched larvae, increased anaphase aberrations in developing embryos, and decreased trout cell growth. The toxic samples generally contained high concentrations of polycyclic aromatic and/or chlorinated hydrocarbons and/or potentially toxic metals. In some cases, concentrations of contaminants on the sea surface exceeded water-quality criteria by several orders of magnitude. Several samples of subsurface bulk water collected below highly contaminated surfaces showed no detectable contamination or toxicity.

  17. Surface Tension Measurements with a Smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-01-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept…

  18. Surface charge measurement using an electrostatic probe

    DEFF Research Database (Denmark)

    Crichton, George C; McAllister, Iain Wilson

    1998-01-01

    During the 1960s, the first measurements of charge on dielectric surfaces using simple electrostatic probes were reported. However it is only within the last 10 years that a proper understanding of the probe response has been developed. This situation arose as a consequence of the earlier studies...

  19. Optical measurement of surface roughness in manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Brodmann, R.

    1984-11-01

    The measuring system described here is based on the light-scattering method, and was developed by Optische Werke G. Rodenstock, Munich. It is especially useful for rapid non-contact monitoring of surface roughness in production-related areas. This paper outlines the differences between this system and the common stylus instrument, including descriptions of some applications in industry.

  20. The influence of Triga 2000 reactor operation on the surface contamination at reactor room using smear test method

    International Nuclear Information System (INIS)

    Bintu Khoiriyyah; Budi Purnama; Tri Cahyo Laksono

    2016-01-01

    The monitoring of surface contamination should be conducted to determine the safety of work areas. Surface contamination at the TRIGA 2000 reactor room which is on PSTNT-BATAN Bandung remain to be implemented although reactor not operating. In this research monitoring of surface contamination when TRIGA 2000 in operation of the first time after several years not operating aims to determine the influence on the results of monitoring. The monitoring of surface contamination has been done using smear test method at some predetermined in TRIGA 2000 reactor room. The highest surface contamination activities is obtained 0.32 Bq/cm 2 and there are some points that are not detected. Based on keputusan kepala BAPETEN No.1/Ka BAPETEN/ V/99 the work showed that the TRIGA 2000 reactor in the category of low area contamination, that is <3.7 Bq/cm 2 to gross beta. (author)

  1. Resistance of Pseudomonas aeruginosa to liquid disinfectants on contaminated surfaces before formation of biofilms.

    Science.gov (United States)

    Sagripanti, J L; Bonifacino, A

    2000-01-01

    A comparison was made of the effectiveness of popular disinfectants (Cavicide, Cidexplus, Clorox, Exspor, Lysol, Renalin, and Wavicide) under conditions prescribed for disinfection in the respective product labels on Pseudomonas aeruginosa either in suspension or deposited onto surfaces of metallic or polymeric plastic devices. The testing also included 7 nonformulated germicidal agents (glutaraldehyde, formaldehyde, peracetic acid, hydrogen peroxide, sodium hypochlorite, phenol, and cupric ascorbate) commonly used in disinfection and decontamination. Results showed that P. aeruginosa is on average 300-fold more resistant when present on contaminated surfaces than in suspension. This increase in resistance agrees with results reported in studies of biofilms, but unexpectedly, it precedes biofilm formation. The surface to which bacteria are attached can influence the effectiveness of disinfectants. Viable bacteria attached to devices may require dislodging through more than a one-step method for detection. The data, obtained with a sensitive and quantitative test, suggest that disinfectants are less effective on contaminated surfaces than generally acknowledged.

  2. A Complete Analytical Screening Identifies the Real Pesticide Contamination of Surface Waters

    Science.gov (United States)

    Moschet, Christoph; Wittmer, Irene; Simovic, Jelena; Junghans, Marion; Singer, Heinz; Stamm, Christian; Leu, Christian; Hollender, Juliane

    2014-05-01

    A comprehensive assessment of pesticides in surface waters is challenging due to the large number of potential contaminants. In Switzerland for example, roughly 500 active ingredients are registered as either plant protection agent (PPA) or as biocide. In addition, an unlimited number of transformations products (TPs) can enter or be formed in surfaced waters. Most scientific publications or regulatory monitoring authorities have implemented 15-40 pesticides in their analytics. Only a few TPs are normally included. Interpretations of the surface water quality based on these subsets remains error prone. In the presented study, we carried out a nearly complete analytical screening covering 86% of all polar organic pesticides (from agricultural and urban sources) in Switzerland (300 substances) and 134 TPs with limits of quantification in the low ng/L range. The comprehensive pesticide screening was conducted by liquid-chromatography coupled to high-resolution tandem mass spectrometry. Five medium-sized rivers (Strahler stream order 3-4, catchment size 35-105 km2), containing high percentiles of diverse crops, orchards and urban settlements in their catchments, were sampled from March till July 2012. Nine subsequent time-proportional bi-weekly composite samples were taken in order to quantify average concentrations. In total, 104 different active ingredients could be detected in at least one of the five rivers. Thereby, 82 substances were only registered as PPA, 20 were registered as PPA and as biocide and 2 were only registered as biocide. Within the PPAs, herbicides had the most frequent detections and the highest concentrations, followed by fungicides and insecticides. Most concentrations were found between 1 and 50 ng/L; however 31 substances (mainly herbicides) had concentrations above 100 ng/L and 3 herbicides above 1000 ng/L. It has to be noted that the measured concentrations are average concentrations over two weeks in medium sized streams and that maximum

  3. Aluminum-contaminant transport by surface runoff and bypass flow from an acid sulphate soil

    NARCIS (Netherlands)

    Minh, L.Q.; Tuong, T.P.; Mensvoort, van M.E.F.; Bouma, J.

    2002-01-01

    Quantifying the process and the amount of acid-contaminant released to the surroundings is important in assessing the environmental hazards associated with reclaiming acid sulphate soils (ASS). The roles of surface runoff and bypass flow (i.e. the rapid downward flow of free water along macropores

  4. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    DEFF Research Database (Denmark)

    Furuse, Adilson Yoshio; da Cunha, Leonardo Fernandes; Benetti, Ana Raquel

    2007-01-01

    of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin...

  5. A new technique for the identification of surface contamination in low temperature bolometric experiments

    International Nuclear Information System (INIS)

    Sangiorgio, S.; Arnaboldi, C.; Brofferio, C.; Bucci, C.; Capelli, S.; Carbone, L.; Clemenza, M.; Cremonesi, O.; Fiorini, E.; Foggetta, L.; Giuliani, A.; Gorla, P.; Nones, C.; Nucciotti, A.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Previtali, E.; Salvioni, C.

    2011-01-01

    In the framework of the bolometric experiment CUORE, a new and promising technique has been developed in order to control the dangerous contamination coming from the surfaces close to the detector. In fact, by means of a composite bolometer, it is possible to partially overcome the loss of spatial resolution of the bolometer itself and to clearly identify events coming from outside.

  6. An integrated model for assessing the risk of TCE groundwater contamination to human receptors and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Funder, S.G.; Rasmussen, J.J.

    2010-01-01

    The practical implementation of the European Water Framework Directive has resulted in an increased focus on the hyporheic zone. In this paper, an integrated model was developed for evaluating the impact of point sources in groundwater on human health and surface water ecosystems....... This was accomplished by coupling the system dynamics-based decision support system CARO-PLUS to the aquatic ecosystem model AQUATOX using an analytical volatilization model for the stream. The model was applied to a case study where a TCE contaminated groundwater plume is discharging to a stream. The TCE source...... will not be depleted for many decades, however measured and predicted TCE concentrations in surface water were found to be below human health risk management targets. Volatilization rapidly attenuates TCE concentrations in surface water. Thus, only a 300 m stream reach fails to meet surface water quality criteria...

  7. TECHNICAL BASIS FOR EVALUATING SURFACE BARRIERS TO PROTECT GROUNDWATER FROM DEEP VADOSE ZONE CONTAMINATION

    International Nuclear Information System (INIS)

    Fayer, J.M.; Freedman, V.L.; Ward, A.L.; Chronister, G.B.

    2010-01-01

    The U.S. DOE and its predecessors released nearly 2 trillion liters (450 billion gallons) of contaminated liquid into the vadose zone at the Hanford Site. Some of the contaminants currently reside in the deeper parts of the vadose zone where they are much less accessible to characterization, monitoring, and typical remediation activities. The DOE Richland Operations Office (DOE-RL) prepared a treatability test plan in 2008 to examine remediation options for addressing contaminants in the deep vadose zone; one of the technologies identified was surface barriers (also known as engineered barriers, covers, and caps). In the typical configuration, the contaminants are located relatively close to the surface, generally within 15 m, and thus they are close to the base of the surface barrier. The proximity of the surface barrier under these conditions yielded few concerns about the effectiveness of the barrier at depth, particularly for cases in which the contaminants were in a lined facility. At Hanford, however, some unlined sites have contaminants located well below depths of 15 m. The issue raised about these sites is the degree of effectiveness of a surface barrier in isolating contaminants in the deep vadose zone. Previous studies by Hanford Site and PNNL researchers suggest that surface barriers have the potential to provide a significant degree of isolation of deep vadose zone contaminants. The studies show that the actual degree of isolation is site-specific and depends on many factors, including recharge rates, barrier size, depth of contaminants, geohydrologic properties ofthe sediments, and the geochemical interactions between the contaminants and the sediments. After the DOE-RL treatability test plan was published, Pacific Northwest National Laboratory was contracted to review the information available to support surface barrier evaluation for the deep vadose zone, identify gaps in the information and outcomes necessary to fill the data gaps, and outline

  8. Surface Contaminant Control Technologies to Improve Laser Damage Resistance of Optics

    Directory of Open Access Journals (Sweden)

    Xiaofeng Cheng

    2014-01-01

    Full Text Available The large high-power solid lasers, such as the National Ignition Facility (NIF of America and the Shenguang-III (SG-III laser facility of China, can output over 2.1 MJ laser pulse for the inertial confinement fusion (ICF experiments. Because of the enhancement of operating flux and the expansion of laser driver scale, the problem of contamination seriously influences their construction period and operation life. During irradiation by intense laser beams, the contaminants on the metallic surface of beam tubes can be transmitted to the optical surfaces and lead to damage of optical components. For the high-power solid-state laser facilities, contamination control focuses on the slab amplifiers, spatial filters, and final-optical assemblies. In this paper, an effective solution to control contaminations including the whole process of the laser driver is put forward to provide the safe operation of laser facilities, and the detailed technical methods of contamination control such as washing, cleanliness metrology, and cleanliness protecting are also introduced to reduce the probability of laser-induced damage of optics. The experimental results show that the cleanliness level of SG-III laser facility is much better to ensure that the laser facility can safely operate at high energy flux.

  9. Effect of electrocardiographic contamination on surface electromyography assessment of back muscles.

    Science.gov (United States)

    Hu, Yong; Mak, Joseph N F; Luk, Keith D K

    2009-02-01

    The purpose of this study was to demonstrate the relative effect of electrocardiography (ECG) on back muscle surface electromyography (SEMG) parameters and their corresponding sensitivity in low back pain (LBP) assessment. Back muscle SEMG activities were recorded from 17 healthy subjects and 18 chronic LBP patients under static postures (straight sitting and upright standing), and dynamic action (flexion-extension). ECG cancellation based on independent component analysis (ICA) method was performed. Root mean square (RMS) and median frequency (MF) of raw and denoised SEMG data were computed respectively. Multiple comparisons were then performed. A consistent trend of change (increased MF and decreased RMS) followed ECG removal was noticed. In particular, in SEMG measurements under static postures, a significant decrease in RMS (pcorruption by ECG artifacts on SEMG measurements was found to be more serious and prominent in static postures than that in dynamic action. After ECG removal, significant improvements in the ability of SEMG to discriminate LBP patients from healthy subjects were seen in RMS amplitude recorded while standing (peffect of ECG contamination on back muscles SEMG parameters and LBP assessment.

  10. Actinide migration from contaminated soil to surface water at the rocky flats environmental technology site

    International Nuclear Information System (INIS)

    Santschi, Peter H.; Roberts, Kimberly

    2002-01-01

    Surficial soils of the Rocky Flats Environmental Technology Site (RFETS) contain elevated levels of 239,240 Pu and 241 Am due to wind dispersal of soil particles, contaminated in the 1960's by leaking drums stored on the 903 Pad. Over the past 4 years, actinide mobility in the surface environment at RFETS, Golden, Colorado, USA, was examined through field and laboratory experiments. From measurements of total 239,240 Pu and 241 Am concentrations in storm runoff and pond discharge samples, collected during spring and summer times, it was established that most of the actinide transport from contaminated soils to streams occurred in the particulate (0.45μm) and colloidal (3kDa - 0.45μm) phases. Controlled laboratory investigations of soil resuspension, indicated that remobilization of colloid-bound Pu during soil erosion events can be enhanced by humic acids. 2-D Polyacrylamide Gel electrophoresis (PAGE) experiments of radiolabeled colloidal organic and inorganic matter, extracted from RFETS soils, suggested that colloidal Pu, which was focused at pH IEP of 4.5, is mainly associated with organic (humic acids) colloids of 10-15 kDa molecular weight. Pu(IV) oxide and inorganic colloids such as iron and aluminum oxides have pH IEP of 8-10. While some clay minerals also have pH IEP of 3-5, no Al was found coincident with Pu. This finding has important ramifications for possible remediation, erosion controls, and land-management strategies. (author)

  11. Residual viral and bacterial contamination of surfaces after cleaning and disinfection.

    Science.gov (United States)

    Tuladhar, Era; Hazeleger, Wilma C; Koopmans, Marion; Zwietering, Marcel H; Beumer, Rijkelt R; Duizer, Erwin

    2012-11-01

    Environmental surfaces contaminated with pathogens can be sources of indirect transmission, and cleaning and disinfection are common interventions focused on reducing contamination levels. We determined the efficacy of cleaning and disinfection procedures for reducing contamination by noroviruses, rotavirus, poliovirus, parechovirus, adenovirus, influenza virus, Staphylococcus aureus, and Salmonella enterica from artificially contaminated stainless steel surfaces. After a single wipe with water, liquid soap, or 250-ppm free chlorine solution, the numbers of infective viruses and bacteria were reduced by 1 log(10) for poliovirus and close to 4 log(10) for influenza virus. There was no significant difference in residual contamination levels after wiping with water, liquid soap, or 250-ppm chlorine solution. When a single wipe with liquid soap was followed by a second wipe using 250- or 1,000-ppm chlorine, an extra 1- to 3-log(10) reduction was achieved, and except for rotavirus and norovirus genogroup I, no significant additional effect of 1,000 ppm compared to 250 ppm was found. A reduced correlation between reduction in PCR units (PCRU) and reduction in infectious particles suggests that at least part of the reduction achieved in the second step is due to inactivation instead of removal alone. We used data on infectious doses and transfer efficiencies to estimate a target level to which the residual contamination should be reduced and found that a single wipe with liquid soap followed by a wipe with 250-ppm free chlorine solution was sufficient to reduce the residual contamination to below the target level for most of the pathogens tested.

  12. Evaluation and study of advanced optical contamination, deposition, measurement, and removal techniques. [including computer programs and ultraviolet reflection analysis

    Science.gov (United States)

    Linford, R. M. F.; Allen, T. H.; Dillow, C. F.

    1975-01-01

    A program is described to design, fabricate and install an experimental work chamber assembly (WCA) to provide a wide range of experimental capability. The WCA incorporates several techniques for studying the kinetics of contaminant films and their effect on optical surfaces. It incorporates the capability for depositing both optical and contaminant films on temperature-controlled samples, and for in-situ measurements of the vacuum ultraviolet reflectance. Ellipsometer optics are mounted on the chamber for film thickness determinations, and other features include access ports for radiation sources and instrumentation. Several supporting studies were conducted to define specific chamber requirements, to determine the sensitivity of the measurement techniques to be incorporated in the chamber, and to establish procedures for handling samples prior to their installation in the chamber. A bibliography and literature survey of contamination-related articles is included.

  13. Radiobiological significance of radioactive contamination - summary assessment based on great number of measurements

    Energy Technology Data Exchange (ETDEWEB)

    Angelov, V [Civil Defence Administration, Sofia (Bulgaria); Bonchev, Ts; Mavrodiev, V; Kyrdzhilov, N [Sofia Univ. (Bulgaria). Fizicheski Fakultet

    1996-12-31

    In order to facilitate quantitative and qualitative characterisation of radioactive contamination the authors introduce a relative estimate of radionuclide activity by setting as a reference the most abundant element -Co-60 in the case of the Kozloduy NPP. The ratio {eta}{sub i} of the mean annual permissible concentration in air for each radionuclide (RPC-92) to that of Co-60 is calculated. It is found that {eta}{sub i} has the same or close values for groups of radionuclides, e.g. {eta}{sub i} = 2.10{sup -4} for {sup 238} Pu, {sup 239} Pu, {sup 240} Pu, {sup 241} Am, {sup 244} Cm; {eta}{sub i} = 5 for {sup 89} Sr, {sup 91} Y; {sup 93} Nb, {sup 134} Cs, {sup 137} Cs; {eta}{sub i} = 50 for {sup 55} Fe, {sup 63} Ni, {sup 95} Zr, {sup 95} Nb, {sup 140} Ba, {sup 140} La. Then it is compared to the experimentally measured values of the same quantity {eta}{sub iexp}, derived from surface contamination data. The ratio {eta}{sub iexp}/{eta}{sub i} is plotted against log {eta}{sub i}. The resulting nomograms give graphic representation of the radiobiological significance of various radionuclide groups. Data from different locations at the Kozloduy NPP are presented. It is found that the alpha emitter contamination has highest values in the Unit 1 (WWER-440) control rooms after repair. The Unit 5 (WWER-1000) has lower alpha contamination compared to WWER-440 units. 1 ref., 5 figs., 1 tab.

  14. Influence of temporally variable groundwater flow conditions on point measurements and contaminant mass flux estimations

    DEFF Research Database (Denmark)

    Rein, Arno; Bauer, S; Dietrich, P

    2009-01-01

    Monitoring of contaminant concentrations, e.g., for the estimation of mass discharge or contaminant degradation rates. often is based on point measurements at observation wells. In addition to the problem, that point measurements may not be spatially representative. a further complication may ari...

  15. Surface aerosol measurements at Barrow during AGASP

    International Nuclear Information System (INIS)

    Bodhaine, B.A.; Dutton, E.G.; DeLuisi, J.J.

    1984-01-01

    Surface aerosol measurements were made at the Barrow GMCC Observatory during the AGASP flight series in March 1983. The condensation nucleus, scattering extinction coefficient, size distribution, and total aerosol optical depth measurements all clearly show conditions of background Arctic haze for March 9-11, a series of haze episodes during March 12-16, and a return to background haze for March 17-18. Angstrom exponents calculated from scattering coefficient data were low during March 9-11, relatively higher during March 12-14, and highest during March 15-18. Surface aerosol data and aerosol optical depth data are in good qualitative agreement for the 10-day period studied. Background haze was present when trajectories circled the Arctic basin, and haze episodes occurred when trajectories originated in western Asia and Europe

  16. Plasma measurements with surface barrier detectors

    International Nuclear Information System (INIS)

    Futch, A.H. Jr.; Bradley, A.E.

    1969-01-01

    A surface barrier detector system for measuring the loss rate of protons from a hydrogen plasma and their energy spectrum is described. A full width at half maximum (FWHM) resolution of 1.4 keV for 15-keV hydrogen atoms was obtained using a selected detector having a sensitive area of 3 mm 2 and a depletion depth of 700 microns

  17. Radioimmunoassay to quantitatively measure cell surface immunoglobulins

    International Nuclear Information System (INIS)

    Krishman, E.C.; Jewell, W.R.

    1975-01-01

    A radioimmunoassay techniques developed to quantitatively measure the presence of immunoglobulins on the surface of cells, is described. The amount of immunoglobulins found on different tumor cells varied from 200 to 1140 ng/10 6 cells. Determination of immunoglobulins on the peripheral lymphocytes obtained from different cancer patients varied between 340 to 1040 ng/10 6 cells. Cultured tumor cells, on the other hand, were found to contain negligible quantities of human IgG [pt

  18. Contaminants of emerging concern in surface waters in Barbados, West Indies.

    Science.gov (United States)

    Edwards, Quincy A; Kulikov, Sergei M; Garner-O'Neale, Leah D; Metcalfe, Chris D; Sultana, Tamanna

    2017-11-14

    Contaminants of emerging concern (CECs), including pharmaceuticals, artificial sweeteners, steroid hormones, and current-use pesticides have been detected in surface waters around the world, but to date, there have been no reports in the peer-reviewed literature on the levels of these classes of contaminants in freshwater resources in the Caribbean region. In the present study, multi-residue solid phase extraction (SPE) and liquid chromatography with tandem mass spectroscopy (LC-MS/MS) were used to analyze grab samples of surface waters collected from five different watersheds in Barbados, West Indies. The artificial sweeteners (AS), acesulfame, cyclamate, saccharin, and sucralose were widely detected in the watersheds, indicating contamination from domestic wastewater, and the concentrations of these chemical tracers in water were correlated with the concentrations of the non-prescription pharmaceutical, ibuprofen (R 2 values of 0.4-0.6). Surprisingly, the concentrations of another chemical tracer of domestic wastewater, caffeine were not correlated with ibuprofen or AS concentrations. Several other prescription pharmaceuticals and the steroid hormones, estrone and androstenedione, were detected in selected watersheds at low ng/L concentrations. The fungicide, chlorothalonil was widely detected in surface waters at low (contamination of water resources by pharmaceuticals.

  19. A decision-making process on cleanup of contaminated surface soil

    International Nuclear Information System (INIS)

    Yasuda, Hiroshi

    1996-01-01

    This study presents principles for determining derived intervention levels (DILs) for surface soil cleanup. The people concerned were divided into major three groups: residents, responsible parties, and cleanup workers; it was considered that each group has different interests. The DILs for soil cleanup were determined from the viewpoints of these three groups: safety of residence, advantages of the countermeasures, and safety of cleanup activities, respectively. An example process for determination of the DILs in accordance with the principles was also presented for a site contaminated by 137 Cs. This decision-making frame is expected to be applicable to other contaminants. (author)

  20. Heavy metal contamination in surface runoff sediments of the urban area of Vilnius, Lithuania

    Directory of Open Access Journals (Sweden)

    Gytautas Ignatavičius

    2017-02-01

    Full Text Available Surface runoff from urbanized territories carries a wide range of pollutants. Sediments in untreated runoff from direct discharge stormwater systems significantly contribute to urban waterway pollution. In this study, heavy metal (Pb, Zn, Cu, Cr, Ba, As and Fe contamination in surface runoff sediments of the urban area of the city of Vilnius was investigated. The surface runoff sediment samples were collected from seven dischargers with the highest volume rate of water flow and concentrations of suspended solids. The geospatial analysis of the distribution of heavy metals shows that there are several active pollution sources supplying the dischargers with contaminated sediments. Most of these areas are located in the central part of the city and in old town with intense traffic. Principal components analysis and t-test results clearly depicted the significantly different chemical compositions of winter and autumn surface sediment samples. The sampling approach and assessment of results provide a useful tool to examine the contamination that is generated in urban areas, distinguish pollution sources and give a better understanding of the importance of permeable surfaces and green areas.

  1. Removal of copper and nickel contaminants from Si surface by use of cyanide solutions

    International Nuclear Information System (INIS)

    Fujiwara, N.; Liu, Y.-L.; Nakamura, T.; Maida, O.; Takahashi, M.; Kobayashi, H.

    2004-01-01

    The cleaning method using cyanide solutions has been developed to remove heavy metals such as copper (Cu) and nickel (Ni) from Si surfaces. Immersion of Si wafers with both Cu and Ni contaminants in potassium cyanide (KCN) solutions of methanol at room temperature decreases these surface concentrations below the detection limit of total reflection X-ray fluorescence spectroscopy of ∼3x10 9 atoms/cm 2 . UV spectra of the KCN solutions after cleaning of the Cu-contaminated Si surface show that stable copper-cyanide complexes are formed in the solution, leading to the prevention of the re-adsorption of copper in the solutions. From the complex stability constants, it is concluded that the Cu(CN) 4 3- is the most dominant species in the KCN solutions

  2. Contribution to Surface Water Contamination Understanding by Pesticides and Pharmaceuticals, at a Watershed Scale

    Directory of Open Access Journals (Sweden)

    Stéphanie Piel

    2012-12-01

    Full Text Available This study aims at understanding the presence of regulated and emerging micropollutants, particularly pesticides and pharmaceuticals, in surface water, regarding spatial and temporal influences at a watershed scale. The study of relations between micropollutants and other water quality and hydroclimatic parameters was carried out from a statistical analysis on historical and experimental data of different sampling sites from the main watershed of Brittany, western France. The outcomes point out the influence of urban and rural areas of the watershed as well as the impact of seasons on contamination variations. This work contributes to health risk assessment related to surface water contamination by micropollutants. This approach is particularly interesting in the case of agricultural watersheds such as the one studied, where more than 80% of surface water is used to produce drinking water.

  3. Laser cleaning of the contaminations on the surface of tire mould

    Science.gov (United States)

    Ye, Yayun; Jia, Baoshen; Chen, Jing; Jiang, Yilan; Tang, Hongping; Wang, Haijun; Luan, Xiaoyu; Liao, Wei; Zhang, Chuanchao; Yao, Caizhen

    2017-07-01

    During the manufacturing of tires, surface pollutants on tire mould will lead to the production of unqualified tires. Tire moulds need to be regularly cleaned. Laser cleaning is recognized as a non-destructive, effective, precise and environmental friendly method. In this paper, laser cleaning was used to remove contaminants on tire mould surface. First, laser induced damage experiments were performed. The results showed that the roughness and hardness of the cast steel sample surface seldom changed under the energy range of 140.1-580.2 mJ laser irradiation 1 pulse and the energy range of 44.7-168.9 mJ laser irradiation 100 pulses. In the laser cleaning experiments, the cleaning thresholds and the optimal cleaning parameters were obtained. Results indicated that laser cleaning was safe and effective for tire mould contamination removal.

  4. Doping profile measurement on textured silicon surface

    Science.gov (United States)

    Essa, Zahi; Taleb, Nadjib; Sermage, Bernard; Broussillou, Cédric; Bazer-Bachi, Barbara; Quillec, Maurice

    2018-04-01

    In crystalline silicon solar cells, the front surface is textured in order to lower the reflection of the incident light and increase the efficiency of the cell. This texturing whose dimensions are a few micrometers wide and high, often makes it difficult to determine the doping profile measurement. We have measured by secondary ion mass spectrometry (SIMS) and electrochemical capacitance voltage profiling the doping profile of implanted phosphorus in alkaline textured and in polished monocrystalline silicon wafers. The paper shows that SIMS gives accurate results provided the primary ion impact angle is small enough. Moreover, the comparison between these two techniques gives an estimation of the concentration of electrically inactive phosphorus atoms.

  5. PROCEEDINGS WITH CONTAMINATED INDUSTRIAL SITES IN TERMS OF NEW LEGISLATION – PART I. HISTORICAL POLLUTION OF THE EARTH'S SURFACE

    OpenAIRE

    Magdalena Paulina Wiśniewska; Agnieszka Pusz

    2017-01-01

    This article shows a way of dealing with the industrial areas, where historical contamination of the earth’s surface occurred, together with an indication of the proper remediation method selection. Public Administration authorities, including the Regional Director of Environmental Protection (RDOŚ) and the governor are responsible, among others, for identifying areas where historical contamination or potential historical contamination of the earth's surface occurred. General Director of Envi...

  6. Highly accurate surface maps from profilometer measurements

    Science.gov (United States)

    Medicus, Kate M.; Nelson, Jessica D.; Mandina, Mike P.

    2013-04-01

    Many aspheres and free-form optical surfaces are measured using a single line trace profilometer which is limiting because accurate 3D corrections are not possible with the single trace. We show a method to produce an accurate fully 2.5D surface height map when measuring a surface with a profilometer using only 6 traces and without expensive hardware. The 6 traces are taken at varying angular positions of the lens, rotating the part between each trace. The output height map contains low form error only, the first 36 Zernikes. The accuracy of the height map is ±10% of the actual Zernike values and within ±3% of the actual peak to valley number. The calculated Zernike values are affected by errors in the angular positioning, by the centering of the lens, and to a small effect, choices made in the processing algorithm. We have found that the angular positioning of the part should be better than 1?, which is achievable with typical hardware. The centering of the lens is essential to achieving accurate measurements. The part must be centered to within 0.5% of the diameter to achieve accurate results. This value is achievable with care, with an indicator, but the part must be edged to a clean diameter.

  7. Evaluation of indigenously developed plastic scintillator sheet detector for surface radioactive contamination monitoring application

    International Nuclear Information System (INIS)

    Sahani, R.M.; Chaudhary, H.S.; Mahala, V.K.; Senwar, K.R.; Meena, J.P.

    2018-01-01

    Radioactive contamination may be caused by release of radioactivity in the environment due to accident at nuclear plant/reactor or spillage of loose radioactive materials in a laboratory. The protection of workers from potentially hazardous radiations emitted by the contaminants is a matter of prime concern. The detection of such radiations requires a monitoring system capable of measuring the level of radioactivity at the contaminated site. Plastic scintillators are widely used for large area radiation monitoring due to the ease of preparation in different shape and sizes. These detectors are sensitive to beta and gamma radiation therefore can be used for monitoring of beta and gamma contamination. In this paper, performance results of indigenously developed plastic scintillator sheet of area 800 cm 2 are reported

  8. Removal and treatment of radioactive, organochlorine, and heavy metal contaminants from solid surfaces

    International Nuclear Information System (INIS)

    Grieco, S.A.; Neubauer, E.D.

    1996-01-01

    The U.S. Department of Energy (DOE) is defining decontamination and decommissioning (D ampersand D) obligations at its sites. Current D ampersand D activities are generally labor intensive, use chemical reagents that are difficult to treat, and may expose workers to radioactive and hazardous chemicals. Therefore, new technologies are desired that minimize waste, allow much of the decommissioned materials to be reused rather than disposed of as waste, and produce wastes that will meet disposal criteria. The O'Brien ampersand Gere companies tested a scouring decontamination system on concrete and steel surfaces contaminated with radioactive and hazardous wastes under the sponsorship of Martin Marietta Energy Systems, Inc. (MMES) at DOE's K-25 former gaseous diffusion plant in Oak Ridge, Tennessee. The scouring system removes fixed radioactive and hazardous contamination yet leaves the surface intact. Blasting residuals are treated using physical/chemical processes. Bench- and pilot-scale testing of the system was conducted on surfaces contaminated with uranium, technetium, heavy metals, and PCBs. Areas of concrete and metal surfaces were blasted. Residuals were dissolved in tap water and treated for radioactive, hazardous, and organochlorine constituents. The treatment system comprised pH adjustment, aeration, solids settling, filtration, carbon adsorption, and ion exchange. This system produced treated water and residual solid waste. Testing demonstrated that the system is capable of removing greater than 95% of radioactive and PCB surface contamination to below DOE's unrestricted use release limits; aqueous radionuclides, heavy metals, and PCBs were below DOE and USEPA treatment objectives after treatment. Waste residuals volume was decreased by 71 %. Preliminary analyses suggest that this system provides significant waste volume reduction and is more economical than alternative surface decontamination techniques that are commercially available or under development

  9. Radioactive contamination of some rubber or plastic surfaces by fission products. Decontamination tests; Contamination radioactive de quelques surfaces en caoutchouc ou en matiere plastique par des produits de fission. Essais de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Mestre, E.; Sautiez, N.

    1957-10-15

    With the objective of notably addressing the contamination and decontamination of gloves and floor covering, this report first presents some characteristics of contaminating radioactive materials (nature, physical and chemical condition), of contaminated surfaces (surface condition, surface nature), and of decontamination processes (physical, chemical or mechanical action). It describes the operational modality implemented to test decontamination processes on various glove or flooring materials: sample preparation, counting, decontamination, reproducibility of decontamination tests, results in terms of activity reduction. It more precisely describes the tested samples: short gloves, gloves from glove boxes, floor and wall coverings. Results are presented and discussed in terms of sample susceptibility to contamination, and of decontamination, but also for re-contamination tests after a Nab-based decontamination (susceptibility to contamination, decontamination gain)

  10. Evaluation of Arctic broadband surface radiation measurements

    Science.gov (United States)

    Matsui, N.; Long, C. N.; Augustine, J.; Halliwell, D.; Uttal, T.; Longenecker, D.; Niebergall, O.; Wendell, J.; Albee, R.

    2012-02-01

    The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW) and thermal infrared, or longwave (LW), radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that keep sensors and shading devices trained on the sun along its diurnal path. High quality measurements require striking a balance between locating stations in a pristine undisturbed setting free of artificial blockage (such as from buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data in the Arctic include solar tracker malfunctions, rime/frost/snow deposition on the protective glass domes of the radiometers and operational problems due to limited operator access in extreme weather conditions. In this study, comparisons are made between the global and component sum (direct [vertical component] + diffuse) SW measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of arctic radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both SW and LW measurements. Solutions to these operational problems that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols are proposed.

  11. Solubility measurement of uranium in uranium-contaminated soils

    International Nuclear Information System (INIS)

    Lee, S.Y.; Elless, M.; Hoffman, F.

    1993-08-01

    A short-term equilibration study involving two uranium-contaminated soils at the Fernald site was conducted as part of the In Situ Remediation Integrated Program. The goal of this study is to predict the behavior of uranium during on-site remediation of these soils. Geochemical modeling was performed on the aqueous species dissolved from these soils following the equilibration study to predict the on-site uranium leaching and transport processes. The soluble levels of total uranium, calcium, magnesium, and carbonate increased continually for the first four weeks. After the first four weeks, these components either reached a steady-state equilibrium or continued linearity throughout the study. Aluminum, potassium, and iron, reached a steady-state concentration within three days. Silica levels approximated the predicted solubility of quartz throughout the study. A much higher level of dissolved uranium was observed in the soil contaminated from spillage of uranium-laden solvents and process effluents than in the soil contaminated from settling of airborne uranium particles ejected from the nearby incinerator. The high levels observed for soluble calcium, magnesium, and bicarbonate are probably the result of magnesium and/or calcium carbonate minerals dissolving in these soils. Geochemical modeling confirms that the uranyl-carbonate complexes are the most stable and dominant in these solutions. The use of carbonate minerals on these soils for erosion control and road construction activities contributes to the leaching of uranium from contaminated soil particles. Dissolved carbonates promote uranium solubility, forming highly mobile anionic species. Mobile uranium species are contaminating the groundwater underlying these soils. The development of a site-specific remediation technology is urgently needed for the FEMP site

  12. Skin and surface lead contamination, hygiene programs, and work practices of bridge surface preparation and painting contractors.

    Science.gov (United States)

    Virji, M Abbas; Woskie, Susan R; Pepper, Lewis D

    2009-02-01

    A 2005 regulatory review of the lead in construction standard by the Occupational Safety and Health Administration (OSHA) noted that alternative pathways of exposure can be as significant as inhalation exposure and that noncompliance with the standard pertaining to hygiene facilities and practices was the second most commonly violated section of the standard. Noncompliance with provisions of the standard and unhealthy work and hygiene practices likely increase the likelihood of take-home lead via contaminated clothing, automobiles, and skin, thus contributing to elevated blood lead levels (BLL) among construction workers and their family members. We performed a cross-sectional study of bridge painters working for small contractors in Massachusetts to investigate causes of persistent elevated BLLs and to assess lead exposures. Thirteen work sites were evaluated for a 2-week period during which surface and skin wipe samples were collected and qualitative information was obtained on personal hygiene practices, decontamination and hand wash facilities, and respiratory protection programs. Results showed lead contamination on workers' skin, respirators, personal automobiles, and the decontamination unit, indicating a significant potential for take-home lead exposure. Overall, the geometric mean (GM) skin lead levels ranged from 373 microg on workers' faces at end of shift to 814 microg on hands at break time. The overall GM lead level inside respirators was 143 microg before work and 286 microg after work. Lead contamination was also present inside workers' personal vehicles as well as on surfaces inside the clean side of the decontamination unit. Review of the respiratory protection programs, work site decontamination and hand wash facilities, and personal hygiene practices indicated that these factors had significant impact on skin and surface contamination levels and identified significant opportunities for improving work site facilities and personal practices

  13. The degradation behaviour of nine diverse contaminants in urban surface water and wastewater prior to water treatment.

    Science.gov (United States)

    Cormier, Guillaume; Barbeau, Benoit; Arp, Hans Peter H; Sauvé, Sébastien

    2015-12-01

    An increasing diversity of emerging contaminants are entering urban surface water and wastewater, posing unknown risks for the environment. One of the main contemporary challenges in ensuring water quality is to design efficient strategies for minimizing such risks. As a first step in such strategies, it is important to establish the fate and degradation behavior of contaminants prior to any engineered secondary water treatment. Such information is relevant for assessing treatment solutions by simple storage, or to assess the impacts of contaminant spreading in the absence of water treatment, such as during times of flooding or in areas of poor infrastructure. Therefore in this study we examined the degradation behavior of a broad array of water contaminants in actual urban surface water and wastewater, in the presence and absence of naturally occurring bacteria and at two temperatures. The chemicals included caffeine, sulfamethoxazole, carbamazepine, atrazine, 17β-estradiol, ethinylestradiol, diclofenac, desethylatrazine and norethindrone. Little information on the degradation behavior of these pollutants in actual influent wastewater exist, nor in general in water for desethylatrazine (a transformation product of atrazine) and the synthetic hormone norethindrone. Investigations were done in aerobic conditions, in the absence of sunlight. The results suggest that all chemicals except estradiol are stable in urban surface water, and in waste water neither abiotic nor biological degradation in the absence of sunlight contribute significantly to the disappearance of desethylatrazine, atrazine, carbamazepine and diclofenac. Biological degradation in wastewater was effective at transforming norethindrone, 17β-estradiol, ethinylestradiol, caffeine and sulfamethoxazole, with measured degradation rate constants k and half-lives ranging respectively from 0.0082-0.52 d(-1) and 1.3-85 days. The obtained degradation data generally followed a pseudo-first-order-kinetic model

  14. Contaminants in surface water and sediments near the Tynagh silver mine site, County Galway, Ireland

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, A. [School of Planning, Architecture and Civil Engineering, Queen' s University of Belfast, Belfast, Northern Ireland (United Kingdom); Phillips, D.H., E-mail: d.phillips@qub.ac.uk [School of Planning, Architecture and Civil Engineering, Queen' s University of Belfast, Belfast, Northern Ireland (United Kingdom); Bowen, J. [School of Planning, Architecture and Civil Engineering, Queen' s University of Belfast, Belfast, Northern Ireland (United Kingdom); Sen Gupta, B. [School of the Built Environment, Hariot-Watt University, Edinburgh, Scotland (United Kingdom)

    2015-04-15

    A former silver mine in Tynagh, Co. Galway, Ireland is one of the most contaminated mine sites in Europe with maximum concentrations of Zn, As, Pb, Mn, Ni, Cu, and Cd far exceeding guideline values for water and sediment. The aims of this research were to 1) further assess the contamination, particularly metals, in surface water and sediment around the site, and 2) determine if the contamination has increased 10 years after the Environmental Protection Agency Ireland (EPAI) identified off-site contamination. Site pH is alkaline to neutral because CaCO{sub 3}-rich sediment and rock material buffer the exposed acid generating sulphide-rich ore. When this study was compared to the previous EPAI study conducted 10 years earlier, it appeared that further weathering of exposed surface sediment had increased concentrations of As and other potentially toxic elements. Water samples from the tailings ponds and adjacent Barnacullia Stream had concentrations of Al, Cd, Mn, Zn and Pb above guideline values. Lead and Zn concentrations from the tailings pond sediment were 16 and 5 times higher, respectively, than concentrations reported 10 years earlier. Pb and Zn levels in most sediment samples exceeded the Expert Group (EGS) guidelines of 1000 and 5000 mg/kg, respectively. Arsenic concentrations were as high as 6238 mg/kg in the tailings ponds sediment, which is 62 and 862 times greater than the EGS and Canadian Soil Quality Guidelines (CSQG), respectively. Cadmium, Cu, Fe, Mn, Pb and Zn concentrations in water and sediment were above guideline values downstream of the site. Additionally, Fe, Mn and organic matter (OM) were strongly correlated and correlated to Zn, Pb, As, Cd, Cu and Ni in stream sediment. Therefore, the nearby Barnacullia Stream is also a significant pathway for contaminant transport to downstream areas. Further rehabilitation of the site may decrease the contamination around the area. - Highlights: • Tynagh silver mine in Co. Galway, Ireland is a source of

  15. Microbial air quality and bacterial surface contamination in ambulances during patient services.

    Science.gov (United States)

    Luksamijarulkul, Pipat; Pipitsangjan, Sirikun

    2015-03-01

    We sought to assess microbial air quality and bacterial surface contamination on medical instruments and the surrounding areas among 30 ambulance runs during service. We performed a cross-sectional study of 106 air samples collected from 30 ambulances before patient services and 212 air samples collected during patient services to assess the bacterial and fungal counts at the two time points. Additionally, 226 surface swab samples were collected from medical instrument surfaces and the surrounding areas before and after ambulance runs. Groups or genus of isolated bacteria and fungi were preliminarily identified by Gram's stain and lactophenol cotton blue. Data were analyzed using descriptive statistics, t-test, and Pearson's correlation coefficient with a p-value of less than 0.050 considered significant. The mean and standard deviation of bacterial and fungal counts at the start of ambulance runs were 318±485cfu/m(3) and 522±581cfu/m(3), respectively. Bacterial counts during patient services were 468±607cfu/m(3) and fungal counts were 656±612cfu/m(3). Mean bacterial and fungal counts during patient services were significantly higher than those at the start of ambulance runs, p=0.005 and p=0.030, respectively. For surface contamination, the overall bacterial counts before and after patient services were 0.8±0.7cfu/cm(2) and 1.3±1.1cfu/cm(2), respectively (pair samples and bacterial counts on medical instruments and allocated areas. This study revealed high microbial contamination (bacterial and fungal) in ambulance air during services and higher bacterial contamination on medical instrument surfaces and allocated areas after ambulance services compared to the start of ambulance runs. Additionally, bacterial and fungal counts in ambulance air showed a significantly positive correlation with the bacterial surface contamination on medical instruments and allocated areas. Further studies should be conducted to determine the optimal intervention to reduce

  16. Surface temperature measurement with radioactive kryptonates

    International Nuclear Information System (INIS)

    Pruzinec, J.; Piatrik, M.

    1976-01-01

    The preparation and use of radioactive kryptonates is described for measuring surface temperatures within the region of 45 to 70 degC. Two samples each were prepared of kryptonated beechwood and hydroquinone on a paper carrier. One sample served as the standard which during the experiment was placed in a thermostat at a constant temperature of 45 degC. The second sample was placed in another thermostat where the temperature changed from 45 to 70 degC. Both samples were in the thermostat for 30 mins. The temperature was raised in steps of 2.5 degC and the time of measurement was constant in both samples. The dependences are given of the drop in activity on temperature for both types of samples. The difference was determined of the drop in activity between the standard and the second sample and the relation for measuring the temperature of the sample was determined therefrom. (J.B.)

  17. Emerging contaminants in surface waters in China—a short review

    International Nuclear Information System (INIS)

    Yang, Guang; Zhang, Guangming; Fan, Maohong

    2014-01-01

    Emerging contaminants (ECs) have drawn attention to many countries due to their persistent input and potential threat to human health and the environment. This article reviews the current contamination sources and their status for surface waters in China. The contamination levels of ECs in surface waters are in the range ng L −1 to μg L −1 in China, apparently about the same as the situation in other countries. ECs enter surface water via runoff, drainage, rainfall, and wastewater treatment effluent. The frequency of occurrence of ECs increased rapidly from 2006 to 2011; a significant reason is the production and consumption of pharmaceuticals and personal care products. As for the distribution of EC pollution in China, the frequency of occurrence of ECs in eastern regions is higher than in western regions. A majority of EC studies have focused on surface waters of the Haihe River and Pearl River watersheds due to their highly developed industries and intense human activity. Legislative and administrative regulation of ECs is lacking in China. To remove ECs, a number of technologies, such as absorption by activated carbon, membrane filtration technology, and advanced oxidation processes, have been researched. (letter)

  18. Microbiological quality control of single-walled carbon-nanotubes-coated surfaces experimentally contaminated

    International Nuclear Information System (INIS)

    Natalizi, T.; Frioni, A.; Passeri, D.; Pantanella, F.

    2013-01-01

    The emergence of new nanotechnologies involves the spreading of nanoparticles in various fields of human life. Nanoparticles in general and, more specifically, carbon nanotubes have been adopted for many practical approaches i.e.: coatings for medical devices, food process industry and drug delivery. Humans will be increasingly exposed to nanoparticles but the susceptibility of nanostructured materials to microbial colonization in process of manufacturing and storage has not been thoroughly considered. Therefore, the microbiological quality control of nanoparticles plays a pivotal role. Different analytical methods have been attempted for detecting bacterial population contaminating a surface, but no one can be considered fully appropriate. Here, BioTimer Assay (BTA) and conventional sonication followed by colony forming units method (S-CFU) were applied for microbiological quality control of single-walled carbon nanotubes (SWCNTs)-coated surfaces experimentally contaminated with Streptococcus mutans and Pseudomonas aeruginosa. Our results demonstrated that S-CFU is unreliable to actually determine the number of bacteria, contaminating abiotic surfaces, as it does not detach all adherent bacteria and kills part of the bacterial population. Instead, BTA is a reliable method to enumerate bacteria colonizing SWCNTs-coated surfaces and can be considered a useful tool for microbiological quality control of nanomaterials for human use.

  19. Emerging contaminants in surface waters in China—a short review

    Science.gov (United States)

    Yang, Guang; Fan, Maohong; Zhang, Guangming

    2014-07-01

    Emerging contaminants (ECs) have drawn attention to many countries due to their persistent input and potential threat to human health and the environment. This article reviews the current contamination sources and their status for surface waters in China. The contamination levels of ECs in surface waters are in the range ng L-1 to μg L-1 in China, apparently about the same as the situation in other countries. ECs enter surface water via runoff, drainage, rainfall, and wastewater treatment effluent. The frequency of occurrence of ECs increased rapidly from 2006 to 2011; a significant reason is the production and consumption of pharmaceuticals and personal care products. As for the distribution of EC pollution in China, the frequency of occurrence of ECs in eastern regions is higher than in western regions. A majority of EC studies have focused on surface waters of the Haihe River and Pearl River watersheds due to their highly developed industries and intense human activity. Legislative and administrative regulation of ECs is lacking in China. To remove ECs, a number of technologies, such as absorption by activated carbon, membrane filtration technology, and advanced oxidation processes, have been researched.

  20. Development of measuring device for inner surfaces of embedded piping (Contract research)

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Hirokuni [Ohyo Koken Kogyo Co., Ltd., Tokyo (Japan); Hatakeyama, Mutsuo [Radioactive Waste Management and Nuclear Facility Decommissioning Technology Center, Tokyo (Japan); Tachibana, Mitsuo; Yanagihara, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The measuring device for inner surfaces of embedded piping (MISE) was developed to evaluate low-level radiological contaminations of inner surfaces of piping. The MISE consists of a cylindrically-formed double layered type detector and a piping crawling robot, which were designed and manufactured separately. In measurements of the contaminations, an outer cylindrical detector close to the surface of piping measures {beta}-rays and {gamma}-rays and an inner cylindrical detector set after a shielding plate for shield of {beta}-rays measures {gamma}-rays. The {beta}-ray counting rates are derived by subtracting {gamma}-ray counts measured by the inner detector from {gamma}- and {beta}-ray counts measured by the outer detector. The piping crawling robot transports the cylindrically-formed double layered type detector with observing inner surfaces of piping. The detection limit for the contamination of {sup 60}Co was found to be about 0.17 Bq/cm{sup 2} with measurement time of 30 seconds. It is expected that 0.2 Bq/cm{sup 2} corresponding to clearance level of {sup 60}Co (0.4 Bq/g) can be evaluated with measurement time of 2 seconds, which is equal to measurement speed of 54 m/h. (author)

  1. Sources, pathways, and relative risks of contaminants in surface water and groundwater: a perspective prepared for the Walkerton inquiry.

    Science.gov (United States)

    Ritter, Len; Solomon, Keith; Sibley, Paul; Hall, Ken; Keen, Patricia; Mattu, Gevan; Linton, Beth

    2002-01-11

    On a global scale, pathogenic contamination of drinking water poses the most significant health risk to humans, and there have been countless numbers of disease outbreaks and poisonings throughout history resulting from exposure to untreated or poorly treated drinking water. However, significant risks to human health may also result from exposure to nonpathogenic, toxic contaminants that are often globally ubiquitous in waters from which drinking water is derived. With this latter point in mind, the objective of this commission paper is to discuss the primary sources of toxic contaminants in surface waters and groundwater, the pathways through which they move in aquatic environments, factors that affect their concentration and structure along the many transport flow paths, and the relative risks that these contaminants pose to human and environmental health. In assessing the relative risk of toxic contaminants in drinking water to humans, we have organized our discussion to follow the classical risk assessment paradigm, with emphasis placed on risk characterization. In doing so, we have focused predominantly on toxic contaminants that have had a demonstrated or potential effect on human health via exposure through drinking water. In the risk assessment process, understanding the sources and pathways for contaminants in the environment is a crucial step in addressing (and reducing) uncertainty associated with estimating the likelihood of exposure to contaminants in drinking water. More importantly, understanding the sources and pathways of contaminants strengthens our ability to quantify effects through accurate measurement and testing, or to predict the likelihood of effects based on empirical models. Understanding the sources, fate, and concentrations of chemicals in water, in conjunction with assessment of effects, not only forms the basis of risk characterization, but also provides critical information required to render decisions regarding regulatory

  2. Fiber-optic Fourier transform infrared spectroscopy for remote label-free sensing of medical device surface contamination

    Science.gov (United States)

    Hassan, Moinuddin; Tan, Xin; Welle, Elissa; Ilev, Ilko

    2013-05-01

    As a potential major source of biochemical contamination, medical device surfaces are of critical safety concerns in the clinical practice and public health. The development of innovative sensing methods for accurate and real-time detection of medical device surface contamination is essential to protect patients from high risk infection. In this paper, we demonstrate an alternative fiber-optic Fourier Transform Infrared (FTIR) spectroscopy based sensing approach for remote, non-contact, and label-free detection of biochemical contaminants in the mid-infrared (mid-IR) region. The sensing probe is designed using mid-IR hollow fibers and FTIR measurements are carried out in reflection mode. Bovine Serum Albumin (BSA) and bacterial endotoxin of different concentrations under thoroughly dry condition are used to evaluate the detection sensitivity. The devised system can identify ≤0.0025% (≤4 × 1011 molecules) BSA and 0.5% (0.5 EU/ml) endotoxin concentration. The developed sensing approach may be applied to detect various pathogens that pose public health threats.

  3. Contamination of the ground waters and surface waters by boron in Lerma Valley, NW-Argentina - an inventory

    International Nuclear Information System (INIS)

    Bundschuh, J.

    1992-01-01

    Ground- and surface waters in areas unaffected by pollution from borax and boric acid producing plants exhibit low boron concentrations of less than 300 μg B/l. Only at the boric acid plant 'Mineratea' is the groundwater contaminated, with up to 6200 μg B/l occurring within an area of 8 to 10 km 2 with more than 1000 μg boron/l. Even higher boron concentrations (up to 18 μg B/l) are present in polluted surface waters. Not the boron concentration in the irrigation water, but the absolute amount of boron added to the plants by irrigation is what determines plant toxicity. For the contaminated area of the boric acid 'Mineratea', characterized by boron concentrations of between 1000 and 6000 μg B/l, the maximal amounts of irrigation water that can be applied lies between 300 and 8 mm. In order to protect the local groundwater resoures from present and future contamination, environmental impact assessment on industrial projects in the area are required. In this way, the quality of the drinking and irrigation water can be guaranteed through suitable measures, without hindering further necessary industrial development of the region. (orig./UWA) [de

  4. Measuring the Valence of Nanocrystal Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Owen, Jonathan Scharle [Columbia Univ., New York, NY (United States)

    2016-11-30

    The goal of this project is to understand and control the interplay between nanocrystal stoichiometry, surface ligand binding and exchange, and the optoelectronic properties of semiconductor nanocrystals in solution and in thin solid films. We pursued three research directions with this goal in mind: 1) We characterized nanocrystal stoichiometry and its influence on the binding of L-type and X-type ligands, including the thermodynamics of binding and the kinetics of ligand exchange. 2) We developed a quantitative understanding of the relationship between surface ligand passivation and photoluminescence quantum yield. 3) We developed methods to replace the organic ligands on the nanocrystal with halide ligands and controllably deposit these nanocrystals into thin films, where electrical measurements were used to investigate the electrical transport and internanocrystal electronic coupling.

  5. Transport of contaminants by Arctic sea ice and surface ocean currents

    International Nuclear Information System (INIS)

    Pfirman, S.

    1995-01-01

    Sea ice and ocean currents transport contaminants in the Arctic from source areas on the shelves, to biologically active regions often more than a thousand kilometers away. Coastal regions along the Siberian margin are polluted by discharges of agricultural, industrial and military wastes in river runoff, from atmospheric deposition and ocean dumping. The Kara Sea is of particular concern because of deliberate dumping of radioactive waste, as well as the large input of polluted river water. Contaminants are incorporated in ice during suspension freezing on the shelves, and by atmospheric deposition during drift. Ice releases its contaminant load through brine drainage, surface runoff of snow and meltwater, and when the floe disintegrates. The marginal ice zone, a region of intense biological activity, may also be the site of major contaminant release. Potentially contaminated ice from the Kara Sea is likely to influence the marginal ice zones of the Barents and Greenland seas. From studies conducted to date it appears that sea ice from the Kara Sea does not typically enter the Beaufort Gyre, and thus is unlikely to affect the northern Canadian and Alaskan margins

  6. Camel meat quality in the slaughterhouse of Ouargla in Algeria. II. Bacterial surface contamination of carcasses

    Directory of Open Access Journals (Sweden)

    A. Benaissa

    2015-10-01

    Full Text Available To assess the microbiological quality of camel meat in the slaughterhouse of Ouargla District in Algeria, the bacterial surface contamination of 60 camel carcasses was investigated. Within an hour after slaughter, swabs were used to collect samples on three sites (thigh, flank and shoulder, just after skinning and before postmortem inspection. Germ rates varied depending on the carcasses and sampling sites. The predominant flora was the total aerobic mesophilic flora, whose contamination level was 2.8  log CFU/cm2 (i.e. 25% of the flora count, followed by enterobacteria with 2.4 log CFU/cm2 (21%, total coliforms with 2.2 log CFU/cm2 (20%, fecal coliforms with 2.0  log CFU/cm2 (18%, and staphylococci with 1.8 log CFU/cm2 (16%. Salmonella and Escherichia coli were detected on all the sampled sites of the carcasses. The camel meat of Ouargla slaughterhouse showed a high level of contamination by pathogenic bacteria (salmonellae and staphylococci. A high fecal contamination (E. coli was also present. Good hygiene practices need to be implemented at slaughter to reduce contaminations.

  7. Airborne spectral measurements of surface anisotropy during SCAR-B

    Science.gov (United States)

    Tsay, Si-Chee; King, Michael D.; Arnold, G. Thomas; Li, Jason Y.

    1998-12-01

    During the Smoke, Clouds, and Radiation-Brazil (SCAR-B) deployment, angular distributions of spectral reflectance for vegetated surfaces and smoke layers were measured using the scanning cloud absorption radiometer (CAR) mounted on the University of Washington C-131A research aircraft. The CAR contains 13 narrowband spectral channels between 0.3 and 2.3 μm with a 190° scan aperture (5° before zenith to 5° past nadir) and 1° instantaneous field of view. The bidirectional reflectance is obtained by flying a clockwise circular orbit above the surface, resulting in a ground track ˜3 km in diameter within about 2 min. Although the CAR measurements are contaminated by minor atmospheric effects, results show distinct spectral characteristics for various types of surfaces. Spectral bidirectional reflectances of three simple and well-defined surfaces are presented: cerrado (August 18, 1995) and dense forest (August 25, 1995), both measured in Brazil under nearly clear-sky conditions, and thick smoke layers over dense forest (September 6 and 11, 1995). The bidirectional reflectances of cerrado and dense forest revealed fairly symmetric patterns along the principal plane, with varying maximal strengths and widths spectrally in the backscattering direction. In the shortwave-infrared region the aerosol effect is very small due to low spectral optical depth. Also, these backscattering maxima can be seen on the bidirectional reflectance of smoke layer over dense forest. These detailed measurements of the angular distribution of spectral reflectance can be parameterized by a few independent variables and utilized to retrieve either surface characteristics or aerosol microphysical and optical properties (e.g., size distribution and single-scattering parameters), if proper physical and radiation models are used. The spectral-hemispherical albedo of these surfaces is obtained directly by integrating all angular measurements and is compared with the measured nadir reflectance

  8. Occurrence of perchloroethylene in surface water and fish in a river ecosystem affected by groundwater contamination.

    Science.gov (United States)

    Wittlingerová, Zdena; Macháčková, Jiřina; Petruželková, Anna; Zimová, Magdalena

    2016-03-01

    Long-term monitoring of the content of perchloroethylene (PCE) in a river ecosystem affected by groundwater contamination was performed at a site in the Czech Republic. The quality of surface water was monitored quarterly between 1994 and 2013, and fish were collected from the affected ecosystem to analyse the content of PCE in their tissue in 1998, 2011 and 2012. Concentrations of PCE (9-140 μg/kg) in the tissue of fish collected from the contaminated part of the river were elevated compared to the part of the river unaffected by the contamination (ND to 5 μg/kg PCE). The quality of surface water has improved as a result of groundwater remediation during the evaluated period. Before the remedial action, PCE concentrations ranged from 30 to 95 μg/L (1994-1997). Following commencement of remedial activities in September 1997, a decrease in the content of PCE in the surface water to 7.3 μg/L (1998) and further to 1 μg/L (2011) and 1.1 μg/L (2012) led to a progressive decrease in the average concentration of PCE in the fish muscle tissue from 79 μg/kg (1998) to 24 (2011) and 30 μg/kg (2012), respectively. It was determined that the bioconcentration of PCE does not have a linear dependence because the decrease in contamination in the fish muscle tissue is not directly proportional to the decrease in contamination in the river water. The observed average bioconcentration factors were 24 and 28 for the lower concentrations of PCE and 11 for the higher concentrations of PCE in the river. In terms of age, length and weight of the collected fish, weight had the greatest significance for bioconcentration, followed by the length, with age being evaluated as a less significant factor.

  9. Field emission and high voltage cleaning of particulate contaminants on extended metallic surfaces

    International Nuclear Information System (INIS)

    Tan, J.; Bonin, B.; Safa, H.

    1996-01-01

    The vacuum insulation properties of extended metallic surfaces depends strongly on their cleanliness. The usual technique to reduce electronic field emission from such surfaces consists in exposing them to very high electric fields during limited periods of time. This kind of processing also reduces the occurrence of vacuum breakdown. The processing of the surface is generally believed to be due to a thermomechanical destruction of the emitting sites, initiated by the emission itself. Comparison of the electric forces vs adherence forces which act on dust particles lying on the surface shows that the processing could also be due simply to the mechanical removal of the dust particles, with a subsequent reduction of field emission from the contaminated surface. (author)

  10. Substantiation of rate setting of surface contamination with amino acids, labelled with tritium

    International Nuclear Information System (INIS)

    Zhesko, T.V.

    1987-01-01

    For rate setting of surface contamination with the wide-spread biogenic tritium compounds-protein predecessors-experimental study of skin absorption and skin deposit of amino acids labelled with tritium is carried out on rats. While extrapolating data to people and calculating tolerable skin contamination with 3 H- amino acids, it is supposed that people arm skin, 100-500 cm 2 , has no defects and that the skin surface decontamination after radionuclide contact is carried out with a preparation, efficiency of which is not less than 97%. The value of tolerable skin absorption of tritium amino acids, being 110-550 MBq/year or 4.8 kBq/cm 2 per one working day, is calculated

  11. Longer Contact Times Increase Cross-Contamination of Enterobacter aerogenes from Surfaces to Food.

    Science.gov (United States)

    Miranda, Robyn C; Schaffner, Donald W

    2016-11-01

    Bacterial cross-contamination from surfaces to food can contribute to foodborne disease. The cross-contamination rate of Enterobacter aerogenes on household surfaces was evaluated by using scenarios that differed by surface type, food type, contact time (food types were watermelon, bread, bread with butter, and gummy candy. Surfaces (25 cm 2 ) were spot inoculated with 1 ml of inoculum and allowed to dry for 5 h, yielding an approximate concentration of 10 7 CFU/surface. Foods (with a 16-cm 2 contact area) were dropped onto the surfaces from a height of 12.5 cm and left to rest as appropriate. Posttransfer, surfaces and foods were placed in sterile filter bags and homogenized or massaged, diluted, and plated on tryptic soy agar. The transfer rate was quantified as the log percent transfer from the surface to the food. Contact time, food, and surface type all had highly significant effects (P food, while the least bacteria transferred to gummy candy (∼0.1 to 62%). Transfer of bacteria to bread (∼0.02 to 94%) was similar to transfer of bacteria to bread with butter (∼0.02 to 82%), and these transfer rates under a given set of conditions were more variable than with watermelon and gummy candy. The popular notion of the "five-second rule" is that food dropped on the floor and left there for foods (watermelon, bread, bread with butter, and gummy candy), four different contact times (food and the surface, are of equal or greater importance. Some transfer takes place "instantaneously," at times of <1 s, disproving the five-second rule. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  12. Evaluation of Arctic broadband surface radiation measurements

    Directory of Open Access Journals (Sweden)

    N. Matsui

    2012-02-01

    Full Text Available The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW and thermal infrared, or longwave (LW, radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers that keep sensors and shading devices trained on the sun along its diurnal path. High quality measurements require striking a balance between locating stations in a pristine undisturbed setting free of artificial blockage (such as from buildings and towers and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data in the Arctic include solar tracker malfunctions, rime/frost/snow deposition on the protective glass domes of the radiometers and operational problems due to limited operator access in extreme weather conditions. In this study, comparisons are made between the global and component sum (direct [vertical component] + diffuse SW measurements. The difference between these two quantities (that theoretically should be zero is used to illustrate the magnitude and seasonality of arctic radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both SW and LW measurements. Solutions to these operational problems that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols are proposed.

  13. Calibration of areal surface topography measuring instruments

    Science.gov (United States)

    Seewig, J.; Eifler, M.

    2017-06-01

    The ISO standards which are related to the calibration of areal surface topography measuring instruments are the ISO 25178-6xx series which defines the relevant metrological characteristics for the calibration of different measuring principles and the ISO 25178-7xx series which defines the actual calibration procedures. As the field of areal measurement is however not yet fully standardized, there are still open questions to be addressed which are subject to current research. Based on this, selected research results of the authors in this area are presented. This includes the design and fabrication of areal material measures. For this topic, two examples are presented with the direct laser writing of a stepless material measure for the calibration of the height axis which is based on the Abbott- Curve and the manufacturing of a Siemens star for the determination of the lateral resolution limit. Based on these results, as well a new definition for the resolution criterion, the small scale fidelity, which is still under discussion, is presented. Additionally, a software solution for automated calibration procedures is outlined.

  14. Carbapenem-Resistant Acinetobacter baumannii: Concomitant Contamination of Air and Environmental Surfaces.

    Science.gov (United States)

    Shimose, Luis A; Masuda, Eriko; Sfeir, Maroun; Berbel Caban, Ana; Bueno, Maria X; dePascale, Dennise; Spychala, Caressa N; Cleary, Timothy; Namias, Nicholas; Kett, Daniel H; Doi, Yohei; Munoz-Price, L Silvia

    2016-07-01

    OBJECTIVE To concomitantly determine the differential degrees of air and environmental contamination by Acinetobacter baumannii based on anatomic source of colonization and type of ICU layout (single-occupancy vs open layout). DESIGN Longitudinal prospective surveillance study of air and environmental surfaces in patient rooms. SETTING A 1,500-bed public teaching hospital in Miami, Florida. PATIENTS Consecutive A. baumannii-colonized patients admitted to our ICUs between October 2013 and February 2014. METHODS Air and environmental surfaces of the rooms of A. baumannii-colonized patients were sampled daily for up to 10 days. Pulsed-field gel electrophoresis (PFGE) was used to type and match the matching air, environmental, and clinical A. baumannii isolates. RESULTS A total of 25 A. baumannii-colonized patients were identified during the study period; 17 were colonized in the respiratory tract and 8 were colonized in the rectum. In rooms with rectally colonized patients, 38.3% of air samples were positive for A. baumannii; in rooms of patients with respiratory colonization, 13.1% of air samples were positive (P=.0001). In rooms with rectally colonized patients, 15.5% of environmental samples were positive for A. baumannii; in rooms of patients with respiratory colonization, 9.5% of environmental samples were positive (P=.02). The rates of air contamination in the open-layout and single-occupancy ICUs were 17.9% and 21.8%, respectively (P=.5). Environmental surfaces were positive in 9.5% of instances in open-layout ICUs versus 13.4% in single-occupancy ICUs (P=.09). CONCLUSIONS Air and environmental surface contaminations were significantly greater among rectally colonized patients; however, ICU layout did not influence the rate of contamination. Infect Control Hosp Epidemiol 2016;37:777-781.

  15. Chemical disinfection of non-porous inanimate surfaces experimentally contaminated with four human pathogenic viruses.

    OpenAIRE

    Sattar, S. A.; Springthorpe, V. S.; Karim, Y.; Loro, P.

    1989-01-01

    The chemical disinfection of virus-contaminated non-porous inanimate surfaces was investigated using coxsackievirus B3, adenovirus type 5, parainfluenza virus type 3 and coronavirus 229E as representatives of important nosocomial viral pathogens. A 10 microliter amount of the test virus, suspended in either faeces or mucin, was placed onto each stainless steel disk (about 1 cm in diameter) and the inoculum allowed to dry for 1 h under ambient conditions. Sixteen disinfectant formulations were...

  16. Multiple containment for LSA [low specific activity] and SCO [surface contaminated objects] wastes

    International Nuclear Information System (INIS)

    Burgess, M.H.

    1993-09-01

    Radioactive wastes are generally transported in the form of Low Specific Activity (LSA) materials or Surface Contaminated Objects (SCO). This report proposes that a method of acknowledging the beneficial effects of multiple containment for such wastes should be written into the 1996 Edition of the IAEA Transport Regulations. Experience used to assess risks from on-site movements of radioactive material in the UK can be applied to develop safety arguments justifying the alleviation of off-site transport risks. (UK)

  17. Model for the assessment of surface radionuclide 210 Pb contamination indoors due to presence of radon

    International Nuclear Information System (INIS)

    Mrdja, D.; Bikit, I.; Forkapic, S.

    2009-01-01

    The model is based on the fact that the change of indoor radon concentration, which periodically enters the room, affects only on radioactive decay and the inserted amount of radon in each impact, but not on its diffusion out, i.e. escape from the room. The aim of the model is to assess the surface contamination of the room by lead 210 Pb. (author) [sr

  18. Risk assessment based on current release standards for radioactive surface contamination

    International Nuclear Information System (INIS)

    Chen, S.Y.

    1993-09-01

    Standards for uncontrolled releases of radioactive surface contamination have been in existence in the United States for about two decades. Such standards have been issued by various agencies, including the US Department of Energy. This paper reviews the technical basis of published standards, identifies areas in need of revision, provides risk interpretations based on current technical knowledge and the regulatory environment, and offers suggestions for improvements

  19. LOFT fuel rod surface temperature measurement testing

    International Nuclear Information System (INIS)

    Eaton, A.M.; Tolman, E.L.; Solbrig, C.W.

    1978-01-01

    Testing of the LOFT fuel rod cladding surface thermocouples has been performed to evaluate how accurately the LOFT thermocouples measure the cladding surface temperature during a loss-of-coolant accident (LOCA) sequence and what effect, if any, the thermocouple would have on core performance. Extensive testing has been done to characterize the thermocouple design. Thermal cycling and corrosion testing of the thermocouple weld design have provided an expected lifetime of 6000 hours when exposed to reactor coolant conditions of 620 K and 15.9 MPa and to sixteen thermal cycles with an initial temperature of 480 K and peak temperatures ranging from 870 to 1200K. Departure from nucleate boiling (DNB) tests have indicated a DNB penalty (5 to 28% lower) during steady state operation and negligible effects during LOCA blowdown caused by the LOFT fuel rod surface thermocouple arrangement. Experience with the thermocouple design in Power Burst Facility (PBF) and LOFT nonnuclear blowdown testing has been quite satisfactory. Tests discussed here were conducted using both stainless steel and zircaloy-clad electrically heated rod in the LOFT Test Support Facility (LTSF) blowdown simulation loop

  20. Detection of fecal contamination on beef meat surfaces using handheld fluorescence imaging device (HFID)

    Science.gov (United States)

    Oh, Mirae; Lee, Hoonsoo; Cho, Hyunjeong; Moon, Sang-Ho; Kim, Eun-Kyung; Kim, Moon S.

    2016-05-01

    Current meat inspection in slaughter plants, for food safety and quality attributes including potential fecal contamination, is conducted through by visual examination human inspectors. A handheld fluorescence-based imaging device (HFID) was developed to be an assistive tool for human inspectors by highlighting contaminated food and food contact surfaces on a display monitor. It can be used under ambient lighting conditions in food processing plants. Critical components of the imaging device includes four 405-nm 10-W LEDs for fluorescence excitation, a charge-coupled device (CCD) camera, optical filter (670 nm used for this study), and Wi-Fi transmitter for broadcasting real-time video/images to monitoring devices such as smartphone and tablet. This study aimed to investigate the effectiveness of HFID in enhancing visual detection of fecal contamination on red meat, fat, and bone surfaces of beef under varying ambient luminous intensities (0, 10, 30, 50 and 70 foot-candles). Overall, diluted feces on fat, red meat and bone areas of beef surfaces were detectable in the 670-nm single-band fluorescence images when using the HFID under 0 to 50 foot-candle ambient lighting.

  1. Mathematical simulation of sediment and contaminant transport in surface waters. Annual report, October 1977--September 1978

    International Nuclear Information System (INIS)

    Onishi, Y.; Arnold, E.M.; Serne, R.J.; Cowan, C.E.; Thompson, F.L.; Mayer, D.W.

    1979-01-01

    Various pathways exist for exposure of humans and biota to radioactive materials released from nuclear facilities. Hydrologic transport (liquid pathway) is one element in the evaluation of the total radiation dose to man. Mathematical models supported by well-planned field data collection programs can be useful tools in assessing the hydrologic transport and ultimate fate of radionuclides. Radionuclides with high distribution coefficients or radionuclides in surface waters with high suspended sediment concentrations are, to a great extent, adsorbed by river and marine sediments. Thus, otherwise dilute contaminants are concentrated. Contaminated sediments may be deposited on the river and ocean beds creating a significant pathway to man. Contaminated bed sediment in turn may become a long-term source of pollution through desorption and resuspension. In order to assess migration and accumulation of radionuclides in surface waters, mathematical models must correctly simulate essential mechanisms of radionuclide transport. The objectives of this study were: (1) to conduct a critical review of (a) radionuclide transport models as well as sediment transport and representative water quality models in rivers, estuaries, oceans, lakes, and reservoirs, and (b) adsorption and desorption mechanisms of radionuclides with sediments in surface waters; (2) to synthesize a mathematical model capable of predicting short- and long-term transport and accumulation of radionuclides in marine environments

  2. Mitigation of cesium and cobalt contamination on the surfaces of RAM packages

    International Nuclear Information System (INIS)

    Krumhansl, J.; Bonhomme, F.; McConnell, P.; Kapoor, A.

    2004-01-01

    Techniques for mitigating the adsorption of 137 Cs and 60 Co on metal surfaces (e.g., RAM packages) exposed to contaminated water (e.g., spent-fuel pools) has been developed and experimentally verified. The techniques are also effective in removing some of the 60 Co and 137 Cs that may have been adsorbed on the surfaces after removal from the contaminated water. The principle for the 137 Cs mitigation technique is based upon ion-exchange processes. In contrast, 60 Co contamination primarily resides in minute particles of CRUD that become lodged on cask surfaces. CRUD is an insoluble Fe-Ni-Cr oxide that forms colloidal-sized particles as stainless steels corrode. Because of the similarity between Ni +2 and Co +2 , CRUD is able to scavenge and retain traces of cobalt as it forms. A number of organic compounds have a great specificity for combining with nickel and cobalt. Ongoing research is investigating the effectiveness of chemical complexing agent, EDTA, with regard to its ability to dissolve the host phase (CRUD) thereby liberating the entrained 60Co into a solution where it can be rinsed away

  3. Linking otolith microchemistry and surface water contamination from natural gas mining.

    Science.gov (United States)

    Keller, David H; Zelanko, Paula M; Gagnon, Joel E; Horwitz, Richard J; Galbraith, Heather S; Velinsky, David J

    2018-09-01

    Unconventional natural gas drilling and the use of hydraulic fracturing technology have expanded rapidly in North America. This expansion has raised concerns of surface water contamination by way of spills and leaks, which may be sporadic, small, and therefore difficult to detect. Here we explore the use of otolith microchemistry as a tool for monitoring surface water contamination from generated waters (GW) of unconventional natural gas drilling. We exposed Brook Trout in the laboratory to three volumetric concentrations of surrogate generated water (SGW) representing GW on day five of drilling. Transects across otolith cross-sections were analyzed for a suite of elements by LA-ICP-MS. Brook Trout exposed to a 0.01-1.0% concentration of SGW for 2, 15, and 30 days showed a significant (p waters and provide support for the use of this technique in natural habitats. To our knowledge, this is the first demonstration of how trace elements in fish otoliths may be used to monitor for surface water contamination from GW. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Study of luminous phenomena observed on contaminated metallic surfaces submitted to high RF fields

    International Nuclear Information System (INIS)

    Maissa, S.; Junquera, T.; Fouaidy, M.; Le Goff, A.; Bonin, B.; Luong, M.; Safa, H.; Tan, J.

    1995-01-01

    The RF field emission from a sample subjected to high RF fields in a copper cavity has been investigated. The study is focused on the luminous emissions occurring on the RF surface simultaneously with the electron emission. The optical apparatus attached to the cavity permits to observe the evolution of the emitters and the direct effects of the surface conditioning. Also, the parameters of the emitted radiation (intensity, glowing duration, spectral distribution) may provide additional informations on the field emission phenomena. Some results concerning samples intentionally contaminated with particles (metallic or dielectric) are presented. (K.A.)

  5. Methane Bubbles Transport Particles From Contaminated Sediment to a Lake Surface

    Science.gov (United States)

    Delwiche, K.; Hemond, H.

    2017-12-01

    Methane bubbling from aquatic sediments has long been known to transport carbon to the atmosphere, but new evidence presented here suggests that methane bubbles also transport particulate matter to a lake surface. This transport pathway is of particular importance in lakes with contaminated sediments, as bubble transport could increase human exposure to toxic metals. The Upper Mystic Lake in Arlington, MA has a documented history of methane bubbling and sediment contamination by arsenic and other heavy metals, and we have conducted laboratory and field studies demonstrating that methane bubbles are capable of transporting sediment particles over depths as great as 15 m in Upper Mystic Lake. Methane bubble traps were used in-situ to capture particles adhered to bubble interfaces, and to relate particle mass transport to bubble flux. Laboratory studies were conducted in a custom-made 15 m tall water column to quantify the relationship between water column height and the mass of particulate transport. We then couple this particle transport data with historical estimates of ebullition from Upper Mystic Lake to quantify the significance of bubble-mediated particle transport to heavy metal cycling within the lake. Results suggest that methane bubbles can represent a significant pathway for contaminated sediment to reach surface waters even in relatively deep water bodies. Given the frequent co-occurrence of contaminated sediments and high bubble flux rates, and the potential for human exposure to heavy metals, it will be critical to study the significance of this transport pathway for a range of sediment and contaminant types.

  6. Development of measuring device for inner surfaces of embedded piping (Contract research)

    CERN Document Server

    Itoh, H; Tachibana, M; Yanagihara, S

    2003-01-01

    The measuring device for inner surfaces of embedded piping (MISE) was developed to evaluate low-level radiological contaminations of inner surfaces of piping. The MISE consists of a cylindrically-formed double layered type detector and a piping crawling robot, which were designed and manufactured separately. In measurements of the contaminations, an outer cylindrical detector close to the surface of piping measures beta-rays and gamma-rays and an inner cylindrical detector set after a shielding plate for shield of beta-rays measures gamma-rays. The beta-ray counting rates are derived by subtracting gamma-ray counts measured by the inner detector from gamma- and beta-ray counts measured by the outer detector. The piping crawling robot transports the cylindrically-formed double layered type detector with observing inner surfaces of piping. The detection limit for the contamination of sup 6 sup 0 Co was found to be about 0.17 Bq/cm sup 2 with measurement time of 30 seconds. It is expected that 0.2 Bq/cm sup 2 co...

  7. Metals Accumulation and Leaf Surface Anatomy of Murdannia spectabilis Growing in Zn/Cd Contaminated Soil

    Directory of Open Access Journals (Sweden)

    Ladawan Rattanapolsan

    2013-07-01

    Full Text Available Murdannia spectabilis (Kurz Faden was identified as a Zn/Cd hyperaccumulative plant. Leaf surface anatomy of the plant growing in non-contaminated soil (control and Zn/Cd contaminated soil,was studied and compared by a light microscopy and scanning electron microscopy combined with Energy-dispersive X-ray spectroscopy(SEM/EDS. The similarities were reticulate cuticle on epidermises, uniform polygonal cell, stomatal arrangement in six surrounding subsidiary cells, and submarginal sclerenchyma. The dissimilarities were uniserate trichomes spreading on both adaxial and abaxial epidermis of the plants growing in non-contaminated soil, whereas the uniserate trichomes were only on the submarginal-adaxial epidermis of the control plants. The trichomes on leaves of the plants growing in non-contaminated soil were found to have both uniseriate non-glandular and uniseriate glandular trichomes;whereas, leaves of the plants growing in the contaminated soil were merely non-glandular trichomes. The different shape and location of trichomes, the number of stomata and trichome indicated the effect of Zn and Cd on M. spectabilis. The higher percentages of Zn and Cd in the vascular bundle than in the cross section and epidermis areas showed both solutes could move along each route, with diffusion through the symplast and apoplast. The increase of Ca in M. spectabilis growing in Zn/Cd contaminated soil corresponded to the Zn and Cd distributed in the leaves. Zn K-edge and S K-edge XANES spectra proposed that Zn2+ ions were accumulated and/or adsorbed on the epidermis of the tuber, and then absorbed into the root and transport to the xylem. The double peaks of Zn-cysteine in the leaf samples proposed the metal sequestration was by sulphur proteins.

  8. Limits determination of microbial contamination present on surfaces from a pharmaceutical microbiology district reference laboratory

    Directory of Open Access Journals (Sweden)

    Natalia Charry

    2016-06-01

    Full Text Available Context: The bioburden present on the pharmaceutical microbiology laboratory’s surfaces, may increase the risk of cross-contamination when analytical tests are being carried out; periodic monitoring allows to set limits that reduce the risk. Aims: To determinate the limits of bioburden present on seven surfaces of the pharmaceutical microbiology laboratory, after the cleaning and disinfection process. Methods: The swabbing method was used for sampling. With a 25 cm2 stencil and a sterile swab, a sample was taken, passing the swab over five points of every surface chosen. A total aerobic microbial count and a total yeast and mold count was done. Finally, the average and the standard deviation of the counts was obtained. Results: The average from the counts obtained on each surface selected for the study, were below the recommended limits by international entities like the World Health Organization and the European Union, between others; also, the results generated in this study, allow to classify the biosafety cabinet as an ISO 5 area and the other areas as ISO 7. Conclusions: Bioburden levels on the tested surfaces are considered low, reducing the risk of cross-contamination, which could have a negative impact on laboratory’s activities. Also, it follows that disinfectant concentration used, is effectively.

  9. Radon-induced surface contaminations in neutrinoless double beta decay and dark matter experiments

    International Nuclear Information System (INIS)

    Pattavina, L.

    2011-01-01

    In experiments looking for rare events, like neutrinoless double beta decay (DBD0ν) and dark matter search (DM), one of the main issues is to increase the experimental sensitivity through the material selection and production. The background contribution coming from the materials used for the detector realization has to be minimized. Moreover the net reduction of the background produced by the bulk part of the apparatus has raised concerns about the background contribution coming from the surfaces. Many procedures and techniques were developed during the last years in order to remove and to minimize the presence of possible contaminants on detector surfaces. To succeed in this strategy a big effort was put in defining all possible mechanisms that lead to surface contaminations, as well as specific cleaning procedures, which are able to reduce and control the surface radioactivity. The presence in air and gases of possible radioactive elements that can stick on the detector surfaces can lead to a recontamination process that will vanish all the applied cleaning procedures. Here is presented and analyzed the contribution to the background of rare events experiments like CUORE experiment (DBD0ν) and EDELWEISS experiment (DM) produced by an exposure of their detector components to a big activity of 222 Rn, radioactive daughter isotope from the 238 U chain. (author)

  10. Determination of the external contamination and cross-contamination by cytotoxic drugs on the surfaces of vials available on the Swiss market.

    Science.gov (United States)

    Fleury-Souverain, Sandrine; Nussbaumer, Susanne; Mattiuzzo, Marc; Bonnabry, Pascal

    2014-04-01

    The external contamination and cross-contamination by cytotoxic drugs on the surface (outside and septum) of 133 vials from various manufacturers and available on the Swiss market were evaluated. All of the tested vials contained one of the following active ingredients: cyclophosphamide, cytarabine, doxorubicin, epirubicin, etoposide phosphate, gemcitabine, ifosfamide, irinotecan, methotrexate or vincristine. The validated wiping liquid chromatography-mass spectrometry method used in this study allowed for the simultaneous determination of these 10 cytotoxic drugs in less than 30 min. External contamination by cytotoxic drugs was detected on 63% of tested vials (outside and septum). The highest contamination level was observed on etoposide phosphate vials with 1896.66 ng of active ingredient on the outside of the vial. Approximately 20% of the contaminated vials had greater than 10 ng of cytotoxic drugs. Chemical contamination on the septum was detected on 38% of the vials. No contamination or very low levels of cytotoxic drugs, less than 1 ng per vial, were detected on the vials protected by plastic shrink-wrap. Traces of cytotoxic drugs different from the active ingredient were detected on 35% of the tested vials. Handling cytotoxic vials with gloves and having a procedure for the decontamination of vials are of the utmost importance for reducing exposure to cytotoxic drugs. Moreover, manufacturers must improve their procedures to provide products free from any contamination.

  11. Atmospheric pressure plasma cleaning of contamination surfaces. 1997 mid-year progress report

    International Nuclear Information System (INIS)

    Hicks, R.; Selwyn, G.S.

    1997-01-01

    'Goals of the project are to (1) identify the key physics and chemistry underlying the use of high pressure plasmas for etching removal of actinides and actinide surrogates; and (2) identify key surface reactions and plasma physics necessary for optimization of the atmospheric pressure plasma jet. Technical description of the work decommissioning of transuranic waste (TRU) into low-level radioactive waste (LLW) represents the largest cleanup cost associated with the nuclear weapons complex. This work is directed towards developing a low-cost plasma technology capable of converting TRU into LLW, based upon highly selective plasma etching of plutonium and other actinides from contaminated surfaces. In this way, only the actinide material is removed, leaving the surface less contaminated. The plasma etches actinide material by producing a volatile halide compound, which may be efficiently trapped using filters. To achieve practical, low-cost operation of a plasma capable of etching actinide materials, the authors have developed a y-mode, resonant-cavity, atmospheric pressure plasma jet (APPJ). In contrast to conventional, low pressure plasmas, the APPJ produces a purely-chemical effluent free of ions, and so achieves very high selectivity and produces negligible damage to the surface. Since the jet operates outside a chamber, many nuclear wastes may be treated including machinery, duct-work, concrete and other building materials. In some cases, it may be necessary to first remove paint from contaminated surfaces using a plasma selective for that surface, then to switch to the actinide etching chemistry for removal of actinide contamination. The goal of this work is to develop the underlying science required for maturation of this technology and to establish early version engineering prototypes. Accomplishments to Date The authors have made significant progress in this program. The work conducted jointly at Los Alamos and at UCLA. This has been facilitated by exchange

  12. Atmospheric pressure plasma cleaning of contamination surfaces. 1997 mid-year progress report

    Energy Technology Data Exchange (ETDEWEB)

    Selwyn, G.S. [Los Alamos National Lab., NM (US); Hicks, R. [Univ. of California, Los Angeles, CA (US)

    1997-06-01

    'Goals of the project are to (1) identify the key physics and chemistry underlying the use of high pressure plasmas for etching removal of actinides and actinide surrogates; and (2) identify key surface reactions and plasma physics necessary for optimization of the atmospheric pressure plasma jet. Technical description of the work decommissioning of transuranic waste (TRU) into low-level radioactive waste (LLW) represents the largest cleanup cost associated with the nuclear weapons complex. This work is directed towards developing a low-cost plasma technology capable of converting TRU into LLW, based upon highly selective plasma etching of plutonium and other actinides from contaminated surfaces. In this way, only the actinide material is removed, leaving the surface less contaminated. The plasma etches actinide material by producing a volatile halide compound, which may be efficiently trapped using filters. To achieve practical, low-cost operation of a plasma capable of etching actinide materials, the authors have developed a y-mode, resonant-cavity, atmospheric pressure plasma jet (APPJ). In contrast to conventional, low pressure plasmas, the APPJ produces a purely-chemical effluent free of ions, and so achieves very high selectivity and produces negligible damage to the surface. Since the jet operates outside a chamber, many nuclear wastes may be treated including machinery, duct-work, concrete and other building materials. In some cases, it may be necessary to first remove paint from contaminated surfaces using a plasma selective for that surface, then to switch to the actinide etching chemistry for removal of actinide contamination. The goal of this work is to develop the underlying science required for maturation of this technology and to establish early version engineering prototypes. Accomplishments to Date The authors have made significant progress in this program. The work conducted jointly at Los Alamos and at UCLA. This has been facilitated by

  13. Using Contaminant Transport Modeling to Determine Historical Discharges at the Surface

    Science.gov (United States)

    Fogwell, T. W.

    2013-12-01

    When it is determined that a contaminated site needs to be remediated, the issue of who is going to pay for that remediation is an immediate concern. This means that there needs to be a determination of who the responsible parties are for the existing contamination. Seldom is it the case that records have been made and kept of the surface contaminant discharges. In many cases it is possible to determine the relative amount of contaminant discharge at the surface of the various responsible parties by employing a careful analysis of the history of contaminant transport through the surface, through the vadose zone, and within the saturated zone. The process begins with the development of a dynamic conceptual site model that takes into account the important features of the transport of the contaminants through the vadose zone and in the groundwater. The parameters for this model can be derived from flow data available for the site. The resulting contaminant transport model is a composite of the vadose zone transport model, together with the saturated zone (groundwater) flow model. Any calibration of the model should be carefully employed in order to avoid using information about the conclusions of the relative discharge amounts of the responsible parties in determining the calibrated parameters. Determination of the leading edge of the plume is an important first step. It is associated with the first discharges from the surface of the site. If there were several discharging parties at the same time, then it is important to establish a chemical or isotopic signature of the chemicals that were discharged. The time duration of the first discharger needs to be determined as accurately as possible in order to establish the appropriate characterization of the leading portion of the resulting plume in the groundwater. The information about the first discharger and the resulting part of the plume associated with this discharger serves as a basis for the determination of the

  14. The Use of Numerical Modeling to Address Surface and Subsurface Water Contamination due to Fracwater Spills in Larry's Creek, Pennsylvania

    Science.gov (United States)

    Simon, C. A.; Arjmand, S.; Abad, J. D.

    2012-12-01

    Because of its relatively low carbon dioxide emissions, natural gas is considered to be more efficient and environmentally friendly than other non-renewable fuels. As a result of this, among other factors, in recent years natural gas has become one of the world's primary energy sources. In the United States, drilling to extract natural gas has substantially increased over the past few years. In the Marcellus Shale, unconventional gas is currently extracted by using two new techniques: horizontal drilling and hydraulic fracturing. Today, fracking fluids which have been applied as part of the hydraulic fracturing process to fracture the shale rock and release the gas, pose a major environmental concern. These fluids are highly contaminated with radionuclides and toxic metals and any exposure of this highly polluted water to surface water or soil could heavily contaminate the media. The area selected for the current study is the Larry's Creek, located in Lycoming County in Pennsylvania. Larry's Creek Watershed was adversely affected by coal and iron mines activities in the 19th century. Though, the water quality in this creek was considered to be good as of 2006. Recently, oil and gas drilling activities have raised concerns about the creek's water quality again. A major environmental hazard is the freshwater contamination by frac/flowback water. Drilling companies are using impoundments on site to keep fracwater, and to store and evaporate flowback water. However, these ponds may fail or leak due to construction problems and/or accidents. Close to Saladasburg, Larry's Creek's stream was observed running rich with clay in October 19, 2011. Historical measurements show very high turbidity during this period which has raised questions about water contamination by the gas industry activities in the upper stream of the watershed. An interstate watershed agency has reported spills in Wolf Run in different drilling sites in the Larry's Creek basin. The focus of this study

  15. Uptake of radionuclides by wheat roots with respect to location of contamination below the surface

    International Nuclear Information System (INIS)

    Suvornmongkhol, Narumon.

    1996-01-01

    The behaviour of 85 Sr, 137 Cs, 54 Mn and 60 Co in terms of plant availability in near surface soil and their root uptake was studied as a function of the location of contamination in the soil profile. Wheat (Triticum aestivum) was employed and the study programme involved both column and hydroponic studies. In the column studies, columns were packed with sandy soil, and either homogeneously or discretely contaminated with the radionuclides, and the water table maintained manually at 3 cm from the bottom. In the discrete contamination, the location of contamination was varied (0-5, 25-30 or 45-50 cm from the top). Wheat plants were grown to maturity in these columns, and harvested at different growth stages to examine radioactivity uptake and its subsequent translocation within the plants. The movement of radionuclides within the soil as well as the soil physicochemical properties were also investigated. The short term uptake kinetics of the hydroponically grown plants during ontogenesis were also studied, both with excised roots and intact plants. The excised root experiment was aimed at investigating the radionuclide by roots of different orders. (author)

  16. Occurrence and behavior of emerging contaminants in surface water and a restored wetland.

    Science.gov (United States)

    Matamoros, Víctor; Arias, Carlos A; Nguyen, Loc Xuan; Salvadó, Victòria; Brix, Hans

    2012-08-01

    Pollution mitigation is an important target for restored wetlands, and although there is much information in relation to nutrient removal, little attention has been paid to emerging contaminants. This paper reports on the occurrence and attenuation capacity of 17 emerging contaminants in a restored wetland and two rivers in North-East Denmark. The compounds belong to the groups of pharmaceuticals, fragrances, antiseptics, fire retardants, pesticides, and plasticizers. Concentrations in surface waters ranged from 2 to 1476 ng L(-1). The compounds with the highest concentrations were diclofenac, 2-methyl-4-chlorophenoxyacetic acid (MCPA), caffeine, and tris(2-chloroethyl) phosphate (TCEP). The herbicide concentrations increased after a rain-fall event, demonstrating the agricultural run-off origin of these compounds, whereas the concentration of the other emerging contaminants was rather conservative. The mitigation capacity of the restored wetland for the compounds ranged from no attenuation to 84% attenuation (19% on average). Hence, restored wetlands may be considered as a feasible alternative for mitigating emerging contaminants from river waters. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Resistance to disinfection of a polymicrobial association contaminating the surface of elastomeric dental impressions.

    Science.gov (United States)

    Giammanco, Giovanni M; Melilli, Dario; Rallo, Antonio; Pecorella, Sonia; Mammina, Caterina; Pizzo, Giuseppe

    2009-04-01

    The aim of this study was to evaluate the ability to resist disinfection of a polymicrobial association contaminating the surface of dental impressions obtained with two different elastomers: a polyether (Impregum) and an addition-polymerized silicone (Elite). Impressions were contaminated with a mixture of three biofilm-forming microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans) and disinfected immediately after contamination, or after microbial layers were allowed to develop during a six-hour storage. Two commercial disinfectants were tested: MD 520 containing 0.5% glutaraldehyde and Sterigum Powder without glutaraldehyde. Residual contamination was recovered by mechanical rinsing immediately after disinfection and after a six-hour storage of disinfected impressions, and assessed by colony counting. Both disinfectants tested were shown to be effective in reducing the microbial presence on the impression materials, achieving at least a 102 reduction of microbial counts compared to water rinsing. However, Sterigum was generally less effective on the Elite elastomer and could not grant disinfection on six-hour aged P. aeruginosa and C. albicans microbial layers. The results of this study suggest that the materials used for the impressions influence the efficacy of disinfection. Disinfectants should be tested according to conditions encountered in everyday clinical practice and the need for immediate disinfection of impressions should be clearly indicated by manufacturers.

  18. Quadrotor helicopter for surface hydrological measurements

    Science.gov (United States)

    Pagano, C.; Tauro, F.; Porfiri, M.; Grimaldi, S.

    2013-12-01

    Surface hydrological measurements are typically performed through user-assisted and intrusive field methodologies which can be inadequate to monitor remote and extended areas. In this poster, we present the design and development of a quadrotor helicopter equipped with digital acquisition system and image calibration units for surface flow measurements. This custom-built aerial vehicle is engineered to be lightweight, low-cost, highly customizable, and stable to guarantee optimal image quality. Quadricopter stability guarantees minimal vibrations during image acquisition and, therefore, improved accuracy in flow velocity estimation through large scale particle image velocimetry algorithms or particle tracking procedures. Stability during the vehicle pitching and rolling is achieved by adopting large arm span and high-wing configurations. Further, the vehicle framework is composed of lightweight aluminum and durable carbon fiber for optimal resilience. The open source Ardupilot microcontroller is used for remote control of the quadricopter. The microcontroller includes an inertial measurement unit (IMU) equipped with accelerometers and gyroscopes for stable flight through feedback control. The vehicle is powered by a 3 cell (11.1V) 3000 mAh Lithium-polymer battery. Electronic equipment and wiring are hosted into the hollow arms and on several carbon fiber platforms in the waterproof fuselage. Four 35A high-torque motors are supported at the far end of each arm with 10 × 4.7 inch propellers. Energy dissipation during landing is accomplished by four pivoting legs that, through the use of shock absorbers, prevent the impact energy from affecting the frame thus causing significant damage. The data capturing system consists of a GoPro Hero3 camera and in-house built camera gimbal and shock absorber damping device. The camera gimbal, hosted below the vehicle fuselage, is engineered to maintain the orthogonality of the camera axis with respect to the water surface by

  19. Techniques for the measurement of the contamination of air; Technique de mesure de la contamination de l'air

    Energy Technology Data Exchange (ETDEWEB)

    Labeyrie, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    This lecture has been given at the International Symposium of Riso 1959. Methods for measuring radioactive content of the atmosphere are described, and main results found at Saclay are given, for the following contaminants: Rn, Tn and their daughter, H-3, C-14, A-41, Kr-85, I-131, and fission products as a whole. (author) [French] Ce texte est celui d'une conference-rapport prononcee au Colloque International de Riso en 1959. On indique les techniques de mesures de la contamination radioactive de l'atmosphere et les principaux resultats obtenus jusqu'ici au CEA pour: Rn et Tn et leurs derives, H-3, C-14, A-41, Kr-85, I-131, et l'ensemble des produits de fission. (auteur)

  20. Morphology and Differentiation of MG63 Osteoblast Cells on Saliva Contaminated Implant Surfaces

    Directory of Open Access Journals (Sweden)

    Neda Shams

    2015-11-01

    Full Text Available Objectives: Osteoblasts are the most important cells in the osseointegration process. Despite years of study on dental Implants, limited studies have discussed the effect of saliva on the adhesion process of osteoblasts to implant surfaces. The aim of this in vitro study was to evaluate the effect of saliva on morphology and differentiation of osteoblasts attached to implant surfaces.Materials and Methods: Twelve Axiom dental implants were divided into two groups. Implants of the case group were placed in containers, containing saliva, for 40 minutes. Then, all the implants were separately stored in a medium containing MG63 human osteoblasts for a week. Cell morphology and differentiation were assessed using a scanning electron microscope and their alkaline phosphatase (ALP activity was determined. The t-test was used to compare the two groups.Results: Scanning electron microscopic observation of osteoblasts revealed round or square cells with fewer and shorter cellular processes in saliva contaminated samples, whereas elongated, fusiform and well-defined cell processes were seen in the control group. ALP level was significantly lower in case compared to control group (P<0.05.Conclusion: Saliva contamination alters osteoblast morphology and differentiation and may subsequently interfere with successful osseointegration. Thus, saliva contamination of bone and implant must be prevented or minimized.

  1. Effect of Hadron Contamination on Dielectron Signal Reconstruction in Heavy Flavor Production Measurements

    International Nuclear Information System (INIS)

    Kikoła, Daniel

    2015-01-01

    Dielectron signal reconstruction is an important tool for heavy flavor measurements because of its trigger feasibility and its relatively straightforward particle identification process. However, in the case of time projection chamber detectors, some hadron contamination is unavoidable, even if additional means are used to improve the particle identification process. In this paper, we investigate the effects of hadron (protons, pions, and kaons) contamination on the dielectron signal reconstruction process in the measurement of J/ψ and electrons from heavy flavor hadron decays

  2. Removal of contaminated concrete surfaces by microwave heating: Phase 1 results

    International Nuclear Information System (INIS)

    White, T.L.; Grubb, R.G.; Pugh, L.P.; Foster, D. Jr.; Box, W.D.

    1992-01-01

    Oak Ridge National Laboratory (ORNL) is developing a microwave heating process to remove radiologically contaminated surface layers from concrete. The microwave energy is directed at the concrete surface and heats the concrete and free water present in the concrete matrix. Continued heating produces steam-pressure-induced mechanical stresses that cause the concrete surface to burst. The concrete particles from this steam explosion are small enough to be removed by a vacuum system, yet less than 1% of the debris is small enough to pose an airborne contamination hazard. The first phase of this program has demonstrated reliable removal of noncontaminated concrete surfaces at frequencies of 2.45 GHz and 10.6 GHz. Continuous concrete removal rates of 1.07 cm 3 /s with 5.2 kW of 2.45.-GHz power and 2.11 cm 3 /s with 3.6 kW of 10.6-GHz power have been demonstrated. Figures-of-merit for microwave removal of concrete have been calculated to be 0.21 cm 3 /s/kW at 2.45 GHz and 0.59 cm 3 /s/kW at 10.6 GHz. The amount of concrete removed in a single pass can be controlled by choosing the frequency and power of the microwave system

  3. Suitability of artificial sweeteners as indicators of raw wastewater contamination in surface water and groundwater.

    Science.gov (United States)

    Tran, Ngoc Han; Hu, Jiangyong; Li, Jinhua; Ong, Say Leong

    2014-01-01

    There is no quantitative data on the occurrence of artificial sweeteners in the aquatic environment in Southeast Asian countries, particularly no information on their suitability as indicators of raw wastewater contamination on surface water and groundwater. This study provided the first quantitative information on the occurrence of artificial sweeteners in raw wastewater, surface water and groundwater in the urban catchment area in Singapore. Acesulfame, cyclamate, saccharin, and sucralose were ubiquitous in raw wastewater samples at concentrations in the range of ng/L-μg/L, while other sweeteners were not found or found only in a few of the raw wastewater samples. Residential and commercial effluents were demonstrated to be the two main sources of artificial sweeteners entering the municipal sewer systems. Relatively higher concentrations of the detected sweeteners were frequently found in surface waters at the sampling sites located in the residential/commercial areas. No significant difference in the concentrations of the detected sweeteners in surface water or groundwater was noted between wet and dry weather conditions (unpaired T-test, p> 0.05). Relatively higher concentrations and detection frequencies of acesulfame, cyclamate and saccharin in surface water samples were observed at the potentially impacted sampling sites, while these sweeteners were absent in most of the background surface water samples. Similarly, acesulfame, cyclamate, and saccharin were found in most groundwater samples at the monitoring well (GW6), which is located close to known leaking sewer segment; whereas these were absent in the background monitoring well, which is located in the catchment with no known wastewater sources. Taken together, the results suggest that acesulfame, cyclamate, and saccharin can be used as potential indicators of raw wastewater contamination in surface water and groundwater. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Development of a Novel Contamination Resistant Ion Chamber for Process Tritium Measurement and Use in the JET First Trace Tritium Experiment

    International Nuclear Information System (INIS)

    Worth, L.B.C.; Pearce, R.J.H.; Bruce, J.; Banks, J.; Scales, S.

    2005-01-01

    The accuracy of process measurements of tritium with conventional ion chambers is often affected by surface tritium contamination. The measurement of tritium in the exhaust of the JET torus is particularly difficult due to surface contamination with highly tritiated hydrocarbons. JET's first unsuccessful attempt to overcome the contamination problem was to use an ion chamber, with a heating element as the chamber wall so that it could be periodically decontaminated by baking. The newly developed ion chamber works on the principle of minimising the surface area within the boundary of the anode and cathode.This paper details the design of the ion chamber, which utilises a grid of 50-micron tungsten wire to define the ion chamber wall and the collector electrode. The effective surface area which, by contamination, is able to effect the measurement of tritium within the process gas has been reduced by a factor of ∼200 over a conventional ion chamber. It is concluded that the new process ion chamber enables sensitive accurate tritium measurements free from contamination issues. It will be a powerful new tool for future tritium experiments both to improve tritium tracking and to help in the understanding of tritium retention issues

  5. Contamination by persistent toxic substances in surface sediment of urban rivers in Chaohu City, China.

    Science.gov (United States)

    Li, Feipeng; Zhang, Haiping; Meng, Xiangzhou; Chen, Ling; Yin, Daqiang

    2012-01-01

    The concentration and spatial distribution of persistent toxic substances (PTS) in the river sediment in Chaohu City, China were investigated. A total of nine surface sediments were collected and the selected PTS pollutants including six heavy metals and nineteen polybrominated diphenyl ethers (PBDEs) were analyzed. The mean heavy metal concentrations (in mg/kg, dry weight) ranged within 0.18-1.53 (Hg), 50.08-200.18 (Cu), 118.70-313.65 (Zn), 50.77-310.85 (Cr), 37.12-92.72 (Pb) and 13.29-197.24 (As), and Cu, Zn and As have been regarded as the main metal pollutants. The levels of PBDEs (1.2-12.1 ng/g) and BDE-209 (2.4-30.5 ng/g) were at the middle level of the global range. BDE-209 was the predominant congener (67.0%-85.7%), which agrees with the fact that technical deca-BDE mixtures are the dominant PBDE formulation in China. The relative high level of PTS pollutants in the western part of the city is probably owing to the intensive agricultural activities and lack of sewerage system there. The ecological risk assessment with the sediment quality guidelines (SOGs) indicates that the urban river sediments in the city have been heavily contaminated by heavy metals with probable ecotoxicological impacts on freshwater organisms and the main toxic pollutants are Hg and As. The results of current study imply that the city, and perhaps many other small cities in China as well, requires immediate pollution control measures with emphasis on not only conventional organic pollutants but also on PTS such as heavy metals and PBDEs.

  6. Surface contamination of spent fuel convoys - resumption of transport in France

    International Nuclear Information System (INIS)

    Pertuis, V.

    2000-01-01

    In France, 1998 was marked by the transport of spent fuel from EDF plants being suspended and then resumed. From the time the first inspections were carried out by the Nuclear Installations Safety Directorate (NISD), in charge of monitoring radioactive and fissile material for civil use since June 1997, surface contamination was found in a high percentage of packages and/or wagons containing spent fuel. The different expert appraisals showed that this had no consequences for the health of the public or of workers. Aiming at the resumption of transport, EDF and Cogema presented to the safety authority a plan of action including an increase in monitoring (number of points and cross-checking by SGS Qualitest), more widespread observance of good practices resulting from analyses by EDF and conclusions of its nuclear inspectorate, and an improvement in radiological cleanliness in the area where casks were loaded. During the inspections carried out at EDF plants, the NISD verified the application of this plan. Several observations were, nevertheless, made regarding maintenance of equipment, failure to apply procedures on a corporate level and the traceability of certain operations. The measures taken to sufficiently inform the public were applied. The NISD is continuing its monitoring actions to ensure that all EDF plants adopt best practices. However, the overall clean-up of EDF plants is a long-term operation. Finally, the NISD is continuing its monitoring of the different stages of spent fuel transport as well as other types of transport of radioactive materials associated with nuclear activities. (author)

  7. Innovative technology for expedited site remediation of extensive surface and subsurface contamination

    International Nuclear Information System (INIS)

    Audibert, J.M.E.; Lew, L.R.

    1994-01-01

    Large scale surface and subsurface contamination resulted from numerous releases of feed stock, process streams, waste streams, and final product at a major chemical plant. Soil and groundwater was contaminated by numerous compounds including lead, tetraethyl lead, ethylene dibromide, ethylene dichloride, and toluene. The state administrative order dictated that the site be investigated fully, that remedial alternative be evaluated, and that the site be remediated within a year period. Because of the acute toxicity and extreme volatility of tetraethyl lead and other organic compounds present at the site and the short time frame ordered by the regulators, innovative approaches were needed to carry out the remediation while protecting plant workers, remediation workers, and the public

  8. Measuring larval nematode contamination on cattle pastures: Comparing two herbage sampling methods.

    Science.gov (United States)

    Verschave, S H; Levecke, B; Duchateau, L; Vercruysse, J; Charlier, J

    2015-06-15

    Assessing levels of pasture larval contamination is frequently used to study the population dynamics of the free-living stages of parasitic nematodes of livestock. Direct quantification of infective larvae (L3) on herbage is the most applied method to measure pasture larval contamination. However, herbage collection remains labour intensive and there is a lack of studies addressing the variation induced by the sampling method and the required sample size. The aim of this study was (1) to compare two different sampling methods in terms of pasture larval count results and time required to sample, (2) to assess the amount of variation in larval counts at the level of sample plot, pasture and season, respectively and (3) to calculate the required sample size to assess pasture larval contamination with a predefined precision using random plots across pasture. Eight young stock pastures of different commercial dairy herds were sampled in three consecutive seasons during the grazing season (spring, summer and autumn). On each pasture, herbage samples were collected through both a double-crossed W-transect with samples taken every 10 steps (method 1) and four random located plots of 0.16 m(2) with collection of all herbage within the plot (method 2). The average (± standard deviation (SD)) pasture larval contamination using sampling methods 1 and 2 was 325 (± 479) and 305 (± 444)L3/kg dry herbage (DH), respectively. Large discrepancies in pasture larval counts of the same pasture and season were often seen between methods, but no significant difference (P = 0.38) in larval counts between methods was found. Less time was required to collect samples with method 2. This difference in collection time between methods was most pronounced for pastures with a surface area larger than 1 ha. The variation in pasture larval counts from samples generated by random plot sampling was mainly due to the repeated measurements on the same pasture in the same season (residual variance

  9. Comparative Measurement of Microcystins in Diverse Surface ...

    Science.gov (United States)

    The measurement of microcystins, cyanotoxins associated with cyanobacterial blooms which are increasingly prevalent in inland waters, is complicated by the diversity of congeners which have been observed in the environment. At present, more than 150 microcystin congeners have been identified, and this poses a significant challenge to analytical methods intended to assess human health risks in surface and drinking water systems. The most widely employed analytical method at present is the ADDA-ELISA technique which is potentially sensitive to all microcystins, but it is primarily intended as a semi-quantitative method, and questions have been raised regarding the potential for cross-reactivity and false positives. LC-MS/MS methods targeting specific congeners, such as US EPA Method 544, are intended for use as a secondary confirmation following a positive ELISA response, but these techniques can target only those congeners for which commercial standards are available. Accordingly, they are not suitable for ascertaining the safety of a given water sample, given the potential for omitting unknown microcystin congeners which might be present.An alternative approach involves oxidative transformation of microcystins to a common product, 2-methyl-3-methoxy-4-phenylbutyric acid, or MMPB. Measuring MMPB by LC-MS/MS can potentially provide a metric for the sum of all microcystin congeners present in a sample, subject to the efficiency and overall yield of conversion. The

  10. Surface tailored organobentonite enhances bacterial proliferation and phenanthrene biodegradation under cadmium co-contamination

    International Nuclear Information System (INIS)

    Mandal, Asit; Biswas, Bhabananda; Sarkar, Binoy; Patra, Ashok K.; Naidu, Ravi

    2016-01-01

    Co-contamination of soil and water with polycyclic aromatic hydrocarbon (PAH) and heavy metals makes biodegradation of the former extremely challenging. Modified clay-modulated microbial degradation provides a novel insight in addressing this issue. This study was conducted to evaluate the growth and phenanthrene degradation performance of Mycobacterium gilvum VF1 in the presence of a palmitic acid (PA)-grafted Arquad® 2HT-75-based organobentonite in cadmium (Cd)-phenanthrene co-contaminated water. The PA-grafted organobentonite (ABP) adsorbed a slightly greater quantity of Cd than bentonite at up to 30 mg L"−"1 metal concentration, but its highly negative surface charge imparted by carboxylic groups indicated the potential of being a significantly superior adsorbent of Cd at higher metal concentrations. In systems co-contained with Cd (5 and 10 mg L"−"1), the Arquad® 2HT-75-modified bentonite (AB) and PA-grafted organobentonite (ABP) resulted in a significantly higher (72–78%) degradation of phenanthrene than bentonite (62%) by the bacterium. The growth and proliferation of bacteria were supported by ABP which not only eliminated Cd toxicity through adsorption but also created a congenial microenvironment for bacterial survival. The macromolecules produced during ABP–bacteria interaction could form a stable clay-bacterial cluster by overcoming the electrostatic repulsion among individual components. Findings of this study provide new insights for designing clay modulated PAH bioremediation technologies in mixed-contaminated water and soil. - Highlights: • Surface tailored organobentonite synthesised and characterised • Modified clay adsorbs Cd and reduces toxicity to Mycobacterium gilvum. • It creates congenial microenvironment for bacterial survival. • It enhances phenanthrene biodegradation in metal co-contaminated condition.

  11. Surface tailored organobentonite enhances bacterial proliferation and phenanthrene biodegradation under cadmium co-contamination

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Asit [Future Industries Institute (formerly Centre for Environmental Risk Assessment and Remediation), University of South Australia, Mawson Lakes, SA 5095 (Australia); Indian Council of Agricultural Research (ICAR), Indian Institute of Soil Science, Bhopal (India); Biswas, Bhabananda [Future Industries Institute (formerly Centre for Environmental Risk Assessment and Remediation), University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), ACT Building, University of Newcastle, Callaghan, NSW 2308 (Australia); Sarkar, Binoy, E-mail: binoy.sarkar@unisa.edu.au [Future Industries Institute (formerly Centre for Environmental Risk Assessment and Remediation), University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), ACT Building, University of Newcastle, Callaghan, NSW 2308 (Australia); Patra, Ashok K. [Indian Council of Agricultural Research (ICAR), Indian Institute of Soil Science, Bhopal (India); Naidu, Ravi, E-mail: ravi.naidu@newcastle.edu.au [Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), ACT Building, University of Newcastle, Callaghan, NSW 2308 (Australia); Global Centre for Environmental Remediation (GCER), Faculty of Science and Information Technology, University of Newcastle, Callaghan, NSW 2308 (Australia)

    2016-04-15

    Co-contamination of soil and water with polycyclic aromatic hydrocarbon (PAH) and heavy metals makes biodegradation of the former extremely challenging. Modified clay-modulated microbial degradation provides a novel insight in addressing this issue. This study was conducted to evaluate the growth and phenanthrene degradation performance of Mycobacterium gilvum VF1 in the presence of a palmitic acid (PA)-grafted Arquad® 2HT-75-based organobentonite in cadmium (Cd)-phenanthrene co-contaminated water. The PA-grafted organobentonite (ABP) adsorbed a slightly greater quantity of Cd than bentonite at up to 30 mg L{sup −1} metal concentration, but its highly negative surface charge imparted by carboxylic groups indicated the potential of being a significantly superior adsorbent of Cd at higher metal concentrations. In systems co-contained with Cd (5 and 10 mg L{sup −1}), the Arquad® 2HT-75-modified bentonite (AB) and PA-grafted organobentonite (ABP) resulted in a significantly higher (72–78%) degradation of phenanthrene than bentonite (62%) by the bacterium. The growth and proliferation of bacteria were supported by ABP which not only eliminated Cd toxicity through adsorption but also created a congenial microenvironment for bacterial survival. The macromolecules produced during ABP–bacteria interaction could form a stable clay-bacterial cluster by overcoming the electrostatic repulsion among individual components. Findings of this study provide new insights for designing clay modulated PAH bioremediation technologies in mixed-contaminated water and soil. - Highlights: • Surface tailored organobentonite synthesised and characterised • Modified clay adsorbs Cd and reduces toxicity to Mycobacterium gilvum. • It creates congenial microenvironment for bacterial survival. • It enhances phenanthrene biodegradation in metal co-contaminated condition.

  12. Wipe sampling for nicotine as a marker of thirdhand tobacco smoke contamination on surfaces in homes, cars, and hotels.

    Science.gov (United States)

    Quintana, Penelope J E; Matt, Georg E; Chatfield, Dale; Zakarian, Joy M; Fortmann, Addie L; Hoh, Eunha

    2013-09-01

    Secondhand smoke contains a mixture of pollutants that can persist in air, dust, and on surfaces for months or longer. This persistent residue is known as thirdhand smoke (THS). Here, we detail a simple method of wipe sampling for nicotine as a marker of accumulated THS on surfaces. We analyzed findings from 5 real-world studies to investigate the performance of wipe sampling for nicotine on surfaces in homes, cars, and hotels in relation to smoking behavior and smoking restrictions. The intraclass correlation coefficient for side-by-side samples was 0.91 (95% CI: 0.87-0.94). Wipe sampling for nicotine reliably distinguished between private homes, private cars, rental cars, and hotels with and without smoking bans and was significantly positively correlated with other measures of tobacco smoke contamination such as air and dust nicotine. The sensitivity and specificity of possible threshold values (0.1, 1, and 10 μg/m(2)) were evaluated for distinguishing between nonsmoking and smoking environments. Sensitivity was highest at a threshold of 0.1 μg/m(2), with 74%-100% of smoker environments showing nicotine levels above threshold. Specificity was highest at a threshold of 10 μg/m(2), with 81%-100% of nonsmoker environments showing nicotine levels below threshold. The optimal threshold will depend on the desired balance of sensitivity and specificity and on the types of smoking and nonsmoking environments. Surface wipe sampling for nicotine is a reliable, valid, and relatively simple collection method to quantify THS contamination on surfaces across a wide range of field settings and to distinguish between nonsmoking and smoking environments.

  13. Clostridium difficile from food and surface samples in a Belgian nursing home: an unlikely source of contamination.

    Science.gov (United States)

    Rodriguez, C; Korsak, N; Taminiau, B; Avesani, V; Van Broeck, J; Brach, P; Delmée, M; Daube, G

    2015-04-01

    This study investigates the contamination of foods and surfaces with Clostridium difficile in a single nursing home. C. difficile PCR-ribotype 078 was found in one food sample and in none of the tested surfaces. These results indicate that food and surfaces are an unlikely source of C. difficile infection in this setting. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Study on agroecology contamination from 125I gas and control measures in a simulated ecosystem

    International Nuclear Information System (INIS)

    Zhao Wenhu; Li Chuanzhao; Xu Shiming; Hou Lanxin; Shang Zhaorong; Li Xia

    1995-09-01

    The study was made in an air-tight space in which a simulated agricultural ecosystem was contaminated from 125 I gas. The contents of the study were summarized as follows: The space and time distribution of 125 I gas, contamination of foliage of the plants, accumulation and transfer of 125 I fallen on the soil and entered into the plants from the roots of crops and vegetables, the time distribution of 125 I in crops in water contaminated from 125 I fallout, distribution, accumulation and transfer of 125 I in chickens and rabbits which inhaled 125 I gas or fed the fodder contaminated from 125 I. The control measures of contamination in agroenvironment from 125 I were discussed. (7 refs., 20 figs., 29 tabs.)

  15. Integrated modelling for assessing the risk of groundwater contaminants to human health and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Rasmussen, Jes; Funder, Simon G.

    2010-01-01

    for evaluating the impact of a TCE groundwater plume, located in an area with protected drinking water interests, to human health and surface water ecosystems. This is accomplished by coupling the system dynamicsbased decision support system CARO-Plus to the aquatic ecosystem model AQUATOX via an analytical......The practical implementation of the European Water Framework Directive has resulted in an increased focus on the groundwater-surface water interaction zone. A gap exists with respect to preliminary assessment methodologies that are capable of evaluating and prioritising point sources...... volatilisation model for the stream. The model is tested on a Danish case study involving a 750 m long TCE groundwater plume discharging into a stream. The initial modelling results indicate that TCE contaminant plumes with μgL-1 concentrations entering surface water systems do not pose a significant risk...

  16. Contamination by urban superficial runoff: accumulated heavy metals on a road surface

    Directory of Open Access Journals (Sweden)

    Carlos Alfonso Zafra Mejía

    2007-01-01

    Full Text Available Studying the behaviour of accumulated contamination on urban surfaces is important in designing control methods minimising the impacts of surface runoff on the environment. This paper presents data regarding the sediment collected on the surface of an urban road in the city of Torrelavega in northern Spain during a period of 65 days during which 132 samples were collected. Two types of sediment collection samples were obtained: vacuumed dry samples (free load and those swept up following vacuuming (fixed load. The results showed that heavy metal concentration in the collected sediment (Pb, Zn, Cu and Cd was inversely proportional to particle diameter. High heavy metal concentrations were found in the smaller fraction (63 pm. Regression equations were calculated for heavy metal concentration regarding particle diameter. Large heavy metal loads were found in the larger fraction (125 pm. The results provide information for analysing runoff water quality in urban areas and designing treatment strategies.

  17. Effectiveness of disinfection with alcohol 70% (w/v of contaminated surfaces not previously cleaned

    Directory of Open Access Journals (Sweden)

    Maurício Uchikawa Graziano

    2013-04-01

    Full Text Available OBJECTIVE: To evaluate the disinfectant effectiveness of alcohol 70% (w/v using friction, without previous cleaning, on work surfaces, as a concurrent disinfecting procedure in Health Services. METHOD: An experimental, randomized and single-blinded laboratory study was undertaken. The samples were enamelled surfaces, intentionally contaminated with Serratia marcescens microorganisms ATCC 14756 106 CFU/mL with 10% of human saliva added, and were submitted to the procedure of disinfection WITHOUT previous cleaning. The results were compared to disinfection preceded by cleaning. RESULTS: There was a reduction of six logarithms of the initial microbial population, equal in the groups WITH and WITHOUT previous cleaning (p=0.440 and a residual microbial load ≤ 102 CFU. CONCLUSION: The research demonstrated the acceptability of the practice evaluated, bringing an important response to the area of health, in particular to Nursing, which most undertakes procedures of concurrent cleaning /disinfecting of these work surfaces.

  18. Effectiveness of disinfection with alcohol 70% (w/v of contaminated surfaces not previously cleaned

    Directory of Open Access Journals (Sweden)

    Maurício Uchikawa Graziano

    Full Text Available OBJECTIVE: To evaluate the disinfectant effectiveness of alcohol 70% (w/v using friction, without previous cleaning, on work surfaces, as a concurrent disinfecting procedure in Health Services. METHOD: An experimental, randomized and single-blinded laboratory study was undertaken. The samples were enamelled surfaces, intentionally contaminated with Serratia marcescens microorganisms ATCC 14756 106 CFU/mL with 10% of human saliva added, and were submitted to the procedure of disinfection WITHOUT previous cleaning. The results were compared to disinfection preceded by cleaning. RESULTS: There was a reduction of six logarithms of the initial microbial population, equal in the groups WITH and WITHOUT previous cleaning (p=0.440 and a residual microbial load ≤ 102 CFU. CONCLUSION: The research demonstrated the acceptability of the practice evaluated, bringing an important response to the area of health, in particular to Nursing, which most undertakes procedures of concurrent cleaning /disinfecting of these work surfaces.

  19. Analysis of body surface radiological contamination for inbound people from Japan to China during the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Yuan Long; Ma Weidong; Lei Cuiping; Chen Huifang; Li Yuwen; Liu Ying

    2012-01-01

    Objective: To investigate the radiological contamination of body surface for inbound people from Japan to China during Fukushima nuclear accident. Methods: According to The guidance for radiological contamination management for body surface issued by Chinese Center for Disease Control and Prevention, for people evacuated from Japan, the body surface monitoring of radiological contamination was performed by the related agencies in main provinces and cities in China. The monitoring data were collected, analyzed and reported to Ministry of Health. Results: A total of 432 persons were checked. The monitoring results of 429 cases were close to the background level, while those of three persons were higher than the background level. Conclusions: In general,the detected results were as low as the background level. The radiological contamination monitoring of body surface for people from Japan could provide scientific data to relax the horror and panic among them. (authors)

  20. An Immunoassay for Quantification of Contamination by Raw Meat Juice on Food Contact Surfaces.

    Science.gov (United States)

    Chen, Fur-Chi; Godwin, Sandria; Chambers, Edgar

    2016-11-01

    Raw chicken products often are contaminated with Salmonella and Campylobacter , which can be transmitted from packages to contact surfaces. Raw meat juices from these packages also provide potential media for cross-contamination. There are limited quantitative data on the levels of consumer exposure to raw meat juice during shopping for and handling of chicken products. An exposure assessment is needed to quantify the levels of transmission and to assess the risk. An enzyme-linked immunosorbent assay (ELISA) was developed and validated for quantitative detection of raw meat juice on hands and various food contact surfaces. Analytical procedures were designed to maximize the recovery of raw meat juice from various surfaces: hands, plastic, wood, stainless steel, laminated countertops, glass, and ceramics. The ELISA was based on the detection of a soluble muscle protein, troponin I (TnI), in the raw meat juice. The assay can detect levels as low as 1.25 ng of TnI, which is equivalent to less than 1 μl of the raw meat juice. The concentrations of TnI in the raw meat juices from 10 retail chicken packages, as determined by ELISA, were between 0.46 and 3.56 ng/μl, with an average of 1.69 ng/μl. The analytical procedures, which include swabbing, extraction, and concentration, enable the detection of TnI from various surfaces. The recoveries of raw meat juice from surfaces of hands were 92%, and recoveries from other tested surfaces were from 55% on plastic cutting boards to 75% on laminated countertops. The ELISA developed has been used for monitoring the transfer of raw meat juice during shopping for and handling of raw chicken products in our studies. The assay also can be applied to other raw meat products, such as pork and beef.

  1. Influence of Surface Adsorption on Work Function Measurements on Gold-Platinum Interface Using Scanning Kelvin Probe Microscopy

    International Nuclear Information System (INIS)

    Mugo, Simon; Yuan Jun

    2012-01-01

    Surface potential difference (SPD) on freshly coated gold and platinum electrodes have been found to be much smaller than bulk work functions consideration and to be dependent on time. We show these discrepancies arise due to formation of surface dipoles caused by adsorbed contaminants in ambient environments. The process is reversible by gentle annealing consistent with contaminant hypothesis. Examination of potential changes on individual electrodes suggest that the Pt surface is more sensitive to ambient conditions than the Au surface in accordance with their relative chemical activities. The result has great implication for interpretation of Kelvin probe measurements obtained on practical devices exposed to ambient environments.

  2. Comparative evaluations of surface contamination detectors calibration with radioactive sources - used in the Goiania accident, and standard sources

    International Nuclear Information System (INIS)

    Becker, P.H.B.; Marecha, M.H.H.

    1997-01-01

    The construction of Cs-137 standard flat sources for calibration of surface contamination detectors, used in the Goiania accident in 1987, is described and the procedures adopted are reported. At that time, standard sources were not available. Nowadays the Instituto de Radioprotecao e Dosimetria has standard sources acquired from Amersham which are used as calibration standards for surface contamination detectors. Comparative evaluations between the standard flat sources constructed for the accident and the calibrated ones are presented

  3. Position-sensitive radiation monitoring (surface contamination monitor). Innovative technology summary report

    International Nuclear Information System (INIS)

    1999-06-01

    The Shonka Research Associates, Inc. Position-Sensitive Radiation Monitor both detects surface radiation and prepares electronic survey map/survey report of surveyed area automatically. The electronically recorded map can be downloaded to a personal computer for review and a map/report can be generated for inclusion in work packages. Switching from beta-gamma detection to alpha detection is relatively simple and entails moving a switch position to alpha and adjusting the voltage level to an alpha detection level. No field calibration is required when switching from beta-gamma to alpha detection. The system can be used for free-release surveys because it meets the federal detection level sensitivity limits requires for surface survey instrumentation. This technology is superior to traditionally-used floor contamination monitor (FCM) and hand-held survey instrumentation because it can precisely register locations of radioactivity and accurately correlate contamination levels to specific locations. Additionally, it can collect and store continuous radiological data in database format, which can be used to produce real-time imagery as well as automated graphics of survey data. Its flexible design can accommodate a variety of detectors. The cost of the innovative technology is 13% to 57% lower than traditional methods. This technology is suited for radiological surveys of flat surfaces at US Department of Energy (DOE) nuclear facility decontamination and decommissioning (D and D) sites or similar public or commercial sites

  4. Purification of fuel and nitrate contaminated ground water using a free water surface constructed wetland plant

    Energy Technology Data Exchange (ETDEWEB)

    Machate, T.; Heuermann, E.; Schramm, K.W.; Kettrup, A.

    1999-10-01

    Contaminated ground water from a former coke plant site was purified in a free water surface (FWS) constructed wetland plant during a 3-mo short-term experiment. The pilot plant (total surface area 27 m{sup 2}) was filled with a 1 m thick lava-gravel substrate planted with cattail (Typha spp.) and bulrush (Scirpus lacustrls). Major contaminants were low to moderate concentrations of polycyclic aromatic hydrocarbons, BTEX, nitrate, and nitrite. The wetland was dosed at hydraulic loading rates of q{sub A} = 4.8 and 9.6 cm d{sup {minus}1} with a hydraulic residence time (HRT) of 13.7 and 6.8 d. The surface removal rates of PAH were between 98.8 and 1914 mg m{sup {minus}2} d{sup {minus}1}. Efficiency was always {gt}99%. Extraction of lava gravel showed that approx. 0.4% of the applied PAH were retained on the substratum. The ratio of {Sigma}2,3-ring PAH and {Sigma}4,5,6-ring PAH showed a shift from 1:0.11 in water to 1:2.5 in lava. The removal of BTEX was {gt}99%, but might be in part due to volatilization. The efficiency in the removal of nitrate was 91% and of nitrite was 97%. Purification performance was not influenced by hydraulic loading rates or after die-back of the macrophytes.

  5. Position-sensitive radiation monitoring (surface contamination monitor). Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    1999-06-01

    The Shonka Research Associates, Inc. Position-Sensitive Radiation Monitor both detects surface radiation and prepares electronic survey map/survey report of surveyed area automatically. The electronically recorded map can be downloaded to a personal computer for review and a map/report can be generated for inclusion in work packages. Switching from beta-gamma detection to alpha detection is relatively simple and entails moving a switch position to alpha and adjusting the voltage level to an alpha detection level. No field calibration is required when switching from beta-gamma to alpha detection. The system can be used for free-release surveys because it meets the federal detection level sensitivity limits requires for surface survey instrumentation. This technology is superior to traditionally-used floor contamination monitor (FCM) and hand-held survey instrumentation because it can precisely register locations of radioactivity and accurately correlate contamination levels to specific locations. Additionally, it can collect and store continuous radiological data in database format, which can be used to produce real-time imagery as well as automated graphics of survey data. Its flexible design can accommodate a variety of detectors. The cost of the innovative technology is 13% to 57% lower than traditional methods. This technology is suited for radiological surveys of flat surfaces at US Department of Energy (DOE) nuclear facility decontamination and decommissioning (D and D) sites or similar public or commercial sites.

  6. Blood Contamination in Saliva: Impact on the Measurement of Salivary Oxidative Stress Markers

    Directory of Open Access Journals (Sweden)

    Natália Kamodyová

    2015-01-01

    Full Text Available Salivary oxidative stress markers represent a promising tool for monitoring of oral diseases. Saliva can often be contaminated by blood, especially in patients with periodontitis. The aim of our study was to examine the impact of blood contamination on the measurement of salivary oxidative stress markers. Saliva samples were collected from 10 healthy volunteers and were artificially contaminated with blood (final concentration 0.001–10%. Next, saliva was collected from 12 gingivitis and 10 control patients before and after dental hygiene treatment. Markers of oxidative stress were measured in all collected saliva samples. Advanced oxidation protein products (AOPP, advanced glycation end products (AGEs, and antioxidant status were changed in 1% blood-contaminated saliva. Salivary AOPP were increased in control and patients after dental treatment (by 45.7% and 34.1%, p<0.01. Salivary AGEs were decreased in patients after microinjury (by 69.3%, p<0.001. Salivary antioxidant status markers were decreased in both control and patients after dental treatment (p<0.05 and p<0.01. One % blood contamination biased concentrations of salivary oxidative stress markers. Saliva samples with 1% blood contamination are visibly discolored and can be excluded from analyses without any specific biochemic detection of blood constituents. Salivary markers of oxidative stress were significantly altered in blood-contaminated saliva in control and patients with gingivitis after dental hygiene treatment.

  7. Experimental measurements of negative hydrogen ion production from surfaces

    International Nuclear Information System (INIS)

    Graham, W.G.

    1977-09-01

    Experimental measurements of the production of H - from surfaces bombarded with hydrogen are reviewed. Some measurements of H + and H 0 production from surfaces are also discussed with particular emphasis on work which might be relevant to ion source applications

  8. Response of monitors of surface contamination to internal exposition control from 131I in the 'nuclear medicine services'

    International Nuclear Information System (INIS)

    Puerta, Nancy; Rojo, Ana M.; Villella, Adrian; Gossio, Sebastian; Parada, Ines Gomez; Acosta, Norma; Arenas, German

    2013-01-01

    The IAEA, in its publication RS-G-1.2, proposes individual control of workers occupationally exposed with risk of internal exposure when the potential exposure provided by incorporation leads to a value of annual committed effective dose equal to or greater than 1 mSv. Because the radionuclide 131 I is the most important to control internal exposure in Nuclear Medicine Services, it is evaluated if the surface contamination monitors, commonly used in nuclear medicine centers of Argentina, would implement individual control of internal exposure to 131 I. Selected detectors were calibrated with a dummy neck and thyroid with calibrated sources of 131 I and 133 Ba reference. For each detector is was estimated the detection efficiency for 131 I and its detection limit. Each instrument was evaluated for the lowest effective dose possible to detect compromised by individual routine monitoring with different measurement intervals . We analyzed the response of each team for determining conditions that may be effective for the control of internal exposure of 131 I. Finally , we conclude that the daily individual monitoring surface contamination detectors available in the Nuclear Medicine Services is feasible to implement and ensures detection of significant additions of 131 I

  9. Measurement of underground contamination of non-aqueous phase liquids (NAPLs) on the basis of the radon concentration in ground level air

    International Nuclear Information System (INIS)

    Schubert, M.

    2001-01-01

    It was investigated whether measurements of radon concentrations in ground level air are a suitable method of detecting sub-surface soil contamination with non-aqueous phase liquids (NAPLs). The working postulation was that, due to the very high solubility of radon in NAPLs, and the resulting accumulation of radon in NAPLs, radon exhalation to the ground level air in the proximity of such NAPL contamination should be locally reduced, thus indicating contamination of sub-surface soils with NAPLs. The research work reported was to verify the working theory by way of experiments, and to finally develop a reliable detection method for NAPL contaminations. The investigations comprised theoretical studies, laboratory experiments, experiments in defined soil columns, and extensive field studies [de

  10. Application of autonomous robotics to surveillance of waste storage containers for radioactive surface contamination

    International Nuclear Information System (INIS)

    Sweeney, F.J.; Beckerman, M.; Butler, P.L.; Jones, J.P.; Reister, D.B.

    1991-01-01

    This paper describes a proof-of-principal demonstration performed with the HERMIES-III mobile robot to automate the inspection of waste storage drums for radioactive surface contamination and thereby reduce the human burden of operating a robot and worker exposure to potentially hazardous environments. Software and hardware for the demonstration were developed by a team consisting of Oak Ridge National Laboratory, and the Universities of Florida, Michigan, Tennessee, and Texas. Robot navigation, machine vision, manipulator control, parallel processing and human-machine interface techniques developed by the team were demonstrated utilizing advanced computer architectures. The demonstration consists of over 100,000 lines of computer code executing on nine computers

  11. Surface Water Contamination and Los Alamos National Laboratory's Holistic Approach to Mitigation

    International Nuclear Information System (INIS)

    Katzman, D.; Veenis, S.; Reneau, S.

    2009-01-01

    A sediment and contaminant transport mitigation project is being implemented at Los Alamos National Laboratory. This effort is driven by a requirement from State of New Mexico regulators and is also in concert with efforts underway to support a surface-water diversion project by a Santa Fe, NM, public water utility. The effort is being implemented in a large geomorphically and hydrologically complex watershed. Rather than simply attempting to trap sediment in a retention basin, this effort uses a watershed-scale holistic approach with intent to promote watershed healing. (authors)

  12. Ion bombardment induced surface topography modification of clean and contaminated single crystal Cu and Si

    International Nuclear Information System (INIS)

    Lewis, G.W.; Kiriakides, G.; Carter, G.; Nobes, M.J.

    1982-01-01

    Among the several factors which lead to depth resolution deterioration during sputter profiling, surface morphological modification resulting from local differences of sputtering rate can be important. This paper reports the results of direct scanning, electron microscopic studies obtained quasi-dynamically during increasing fluence ion bombardment of the evolution of etch pit structures on Si and Cu, and how such elaboration may be suppressed. It also reports on the elaboration of contaminant-induced cone generation for different ion species bombardment. The influence of such etch pit and cone generation on achievable depth resolution is assessed. (author)

  13. Reference sources for the calibration of surface contamination monitors - Beta-emitters (maximum beta energy greater than MeV) and alpha-emitters (International Standard Publication ISO 8769:1988)

    International Nuclear Information System (INIS)

    Stefanik, J.

    2001-01-01

    This International Standard specifies the characteristics of reference sources of radioactive surface contamination, traceable to national measurement standards, for the calibration of surface contamination monitors. This International Standard relates to alpha-emitters and to beta-emitters of maximum beta energy greater than 0,15 MeV. It does not describe the procedures involved in the use of these reference sources for the calibration of surface contamination monitors. Such procedures are specified in IEC Publication 325 and other documents. This International Standard specifies reference radiations for the calibration of surface contamination monitors which take the form of adequately characterized large area sources specified, without exception, in terms of activity and surface emission rate, the evaluation of these quantities being traceable to national standards

  14. Sampling for Beryllium Surface Contamination using Wet, Dry and Alcohol Wipe Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, Kent [Central Missouri State Univ., Warrensburg, MO (United States)

    2004-12-01

    This research project was conducted at the National Nuclear Security Administration's Kansas City Plant, operated by Honeywell Federal Manufacturing and Technologies, in conjunction with the Safety Sciences Department of Central Missouri State University, to compare relative removal efficiencies of three wipe sampling techniques currently used at Department of Energy facilities. Efficiencies of removal of beryllium contamination from typical painted surfaces were tested by wipe sampling with dry Whatman 42 filter paper, with water-moistened (Ghost Wipe) materials, and by methanol-moistened wipes. Test plates were prepared using 100 mm X 15 mm Pyrex Petri dishes with interior surfaces spray painted with a bond coat primer. To achieve uniform deposition over the test plate surface, 10 ml aliquots of solution containing 1 beryllium and 0.1 ml of metal working fluid were transferred to the test plates and subsequently evaporated. Metal working fluid was added to simulate the slight oiliness common on surfaces in metal working shops where fugitive oil mist accumulates over time. Sixteen test plates for each wipe method (dry, water, and methanol) were processed and sampled using a modification of wiping patterns recommended by OSHA Method 125G. Laboratory and statistical analysis showed that methanol-moistened wipe sampling removed significantly more (about twice as much) beryllium/oil-film surface contamination as water-moistened wipes (p< 0.001), which removed significantly more (about twice as much) residue as dry wipes (p <0.001). Evidence for beryllium sensitization via skin exposure argues in favor of wipe sampling with wetting agents that provide enhanced residue removal efficiency.

  15. Biosurfactants and increased bioavailability of sorbed organic contaminants: Measurements using a biosensor

    International Nuclear Information System (INIS)

    Strong-Gunderson, J.M.; Palumbo, A.V.; Applegate, B.; Saylor, G.S.

    1993-01-01

    Bioremediation of sites contaminated with hydrophobic materials that sorb onto the soil matrix is very difficult due to reduced microbial (bio)availability. Following biosurfactant addition, we have measured an increase in contaminant bioavailability by using a lux biosensor. Direct microbial bioavailability was determined by using a genetically engineered microbial bioreporter strain of Pseudomonas putida. This strain was engineered so the lux genes, which code for light production, are transcriptionally fused with genes that code for contaminant degradation and are thus induced in the presence of specific compounds. By using a bioreporter we can quantify the actual microbial bioavailability of the contaminants and compare it to concentrations measured by other analytical methods (e.g. gas chromatograph). It is possible that these values are not equal to each other. Thus, bioremediation rates may not be accurately predicted if bioavailability is not considered

  16. A model to determine the radiological implications of non-fixed radioactive contamination on the surfaces of packages and conveyances

    International Nuclear Information System (INIS)

    Hughes, J.S.; Warner Jones, S.M.; Lizot, M.T.; Perrin, M.L.; Thierfeld, S.; Schroedl, E.; Schwarz, G.; Rawl, R.; Munakata, M.; Hirose, M.

    2004-01-01

    The surfaces of packages and conveyances used to transport radioactive materials can sometimes become contaminated with radioactive material. This usually occurs as a result of the transfer of radioactive material from areas in which these packages and conveyances are handled. This contamination may subsequently be transferred to transport equipment, workers and to areas accessible to the public. This can represent a significant radiation safety issue that requires careful management. The current regulatory limits for non-fixed contamination on packages and conveyances have been in use for over 40 years, and are based on a simple exposure model. However, the bases on which these limits were derived have been subject to changes, as a result of successive revisions of international recommendations. In recognition of this need for a review and analysis of the current contamination limits an IAEA Co-ordinated Research Project (CRP) on the ''Radiological Aspects of Package and Conveyance Non-Fixed Contamination'' was initiated to review the scientific basis for the current regulatory limits for surface contamination. The CRP was also to develop guidance material for evaluating the radiological significance of surface contamination to workers and the public in light of state-of-the-art research, technical developments and current transport practices. The specific objectives of the work undertaken within this multi-national CRP were, in accordance with the terms of reference: To ensure that appropriate models exist for all package types including consideration of the aspects pertinent for assessing and revising a surface contamination model for transport. To collect - where possible - contamination, operational and dosimetric data to ensure modelling consistency. To use models for assessing the limitations and optimisation of radiation doses incurred in transport operations, and to consider preventive methods for package and conveyance contamination

  17. A Review of Removable Surface Contamination on Radioactive Materials Transportation Containers

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Jr, W. E.; Watson, E. C.; Murphy, D. W.; Harrer, B. J.; Harty, R.; Aldrich, J. M.

    1981-05-01

    This report contains the results of a study sponsored by the U.S. Nuclear Regulatory Commission (NRC) of removable surface contamination on radioactive materials transportation containers. The purpose of the study is to provide information to the NRC during their review of existing regulations. Data was obtained from both industry and literature on three major topics: 1) radiation doses, 2) economic costs, and 3) contamination frequencies. Containers for four categories of radioactive materials are considered including radiopharmaceuticals, industrial sources, nuclear fuel cycle materials, and low-level radioactive waste. Assumptions made in this study use current information to obtain realistic yet conservative estimates of radiation dose and economic costs. Collective and individual radiation doses are presented for each container category on a per container basis. Total doses, to workers and the public, are also presented for spent fuel cask and low-level waste drum decontamination. Estimates of the additional economic costs incurred by lowering current limits by factors of 10 and 100 are presented. Current contamination levels for each category of container are estimated from the data collected. The information contained in this report is designed to be useful to the NRC in preparing their recommendations for new regulations.

  18. Simple surface foam application enhances bioremediation of oil-contaminated soil in cold conditions.

    Science.gov (United States)

    Jeong, Seung-Woo; Jeong, Jongshin; Kim, Jaisoo

    2015-04-09

    Landfarming of oil-contaminated soil is ineffective at low temperatures, because the number and activity of micro-organisms declines. This study presents a simple and versatile technique for bioremediation of diesel-contaminated soil, which involves spraying foam on the soil surface without additional works such as tilling, or supply of water and air. Surfactant foam containing psychrophilic oil-degrading microbes and nutrients was sprayed twice daily over diesel-contaminated soil at 6 °C. Removal efficiencies in total petroleum hydrocarbon (TPH) at 30 days were 46.3% for landfarming and 73.7% for foam-spraying. The first-order kinetic biodegradation rates for landfarming and foam-spraying were calculated as 0.019 d(-1) and 0.044 d(-1), respectively. Foam acted as an insulating medium, keeping the soil 2 °C warmer than ambient air. Sprayed foam was slowly converted to aqueous solution within 10-12h and infiltrated the soil, providing microbes, nutrients, water, and air for bioaugmentation. Furthermore, surfactant present in the aqueous solution accelerated the dissolution of oil from the soil, resulting in readily biodegradable aqueous form. Significant reductions in hydrocarbon concentration were simultaneously observed in both semi-volatile and non-volatile fractions. As the initial soil TPH concentration increased, the TPH removal rate of the foam-spraying method also increased. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Development of a Passive Multisampling Method to Measure Dioxins/Furans and Other Contaminant Bioavailability in Aquatic Sediments

    Science.gov (United States)

    2016-11-01

    FINAL REPORT Development of a Passive Multisampling Method to Measure Dioxins/Furans and Other Contaminant Bioavailability in Aquatic...passive multisampling method to measure Dioxins/Furans 5a. CONTRACT NUMBER and other contaminant bioavailability in aquatic sediments...This also indicates the bioavailability or pressure (fugacity) of contaminants on organisms2 and consequently represents the exposure level for

  20. PROCEEDINGS WITH CONTAMINATED INDUSTRIAL SITES IN TERMS OF NEW LEGISLATION – PART I. HISTORICAL POLLUTION OF THE EARTH'S SURFACE

    Directory of Open Access Journals (Sweden)

    Magdalena Paulina Wiśniewska

    2017-02-01

    Full Text Available This article shows a way of dealing with the industrial areas, where historical contamination of the earth’s surface occurred, together with an indication of the proper remediation method selection. Public Administration authorities, including the Regional Director of Environmental Protection (RDOŚ and the governor are responsible, among others, for identifying areas where historical contamination or potential historical contamination of the earth's surface occurred. General Director of Environmental Protection is responsible for conducting and updating the registry, which contains information on identified by RDOŚ and district governor contaminated areas. The article discusses also issues related to the duties and responsibilities wielding the earth's surface, as well as the costs of using the environment, taking into account the "polluter pays" principle.

  1. Wipe-rinse technique for quantitating microbial contamination on large surfaces

    Science.gov (United States)

    Kirschner, L. E.; Puleo, J. R.

    1979-01-01

    The evaluation of an improved wipe-rinse technique for the bioassay of large areas was undertaken due to inherent inadequacies in the cotton swab-rinse technique to which assay of spacecraft is currently restricted. Four types of contamination control cloths were initially tested. A polyester-bonded cloth (PBC) was selected for further evaluation because of its superior efficiency and handling characteristics. Results from comparative tests with PBC and cotton swabs on simulated spacecraft surfaces indicated a significantly higher recovery efficiency for the PBC than for the cotton (90.4 versus 75.2%). Of the sampling area sites studied, PBC was found to be most effective on surface areas not exceeding 0.74 sq m (8.0 sq ft).

  2. Probing Anisotropic Surface Properties of Molybdenite by Direct Force Measurements.

    Science.gov (United States)

    Lu, Zhenzhen; Liu, Qingxia; Xu, Zhenghe; Zeng, Hongbo

    2015-10-27

    Probing anisotropic surface properties of layer-type mineral is fundamentally important in understanding its surface charge and wettability for a variety of applications. In this study, the surface properties of the face and the edge surfaces of natural molybdenite (MoS2) were investigated by direct surface force measurements using atomic force microscope (AFM). The interaction forces between the AFM tip (Si3N4) and face or edge surface of molybdenite were measured in 10 mM NaCl solutions at various pHs. The force profiles were well-fitted with classical DLVO (Derjaguin-Landau-Verwey-Overbeek) theory to determine the surface potentials of the face and the edge surfaces of molybdenite. The surface potentials of both the face and edge surfaces become more negative with increasing pH. At neutral and alkaline conditions, the edge surface exhibits more negative surface potential than the face surface, which is possibly due to molybdate and hydromolybdate ions on the edge surface. The point of zero charge (PZC) of the edge surface was determined around pH 3 while PZC of the face surface was not observed in the range of pH 3-11. The interaction forces between octadecyltrichlorosilane-treated AFM tip (OTS-tip) and face or edge surface of molybdenite were also measured at various pHs to study the wettability of molybdenite surfaces. An attractive force between the OTS-tip and the face surface was detected. The force profiles were well-fitted by considering DLVO forces and additional hydrophobic force. Our results suggest the hydrophobic feature of the face surface of molybdenite. In contrast, no attractive force between the OTS-tip and the edge surface was detected. This is the first study in directly measuring surface charge and wettability of the pristine face and edge surfaces of molybdenite through surface force measurements.

  3. Nano-TiO2-based photocatalytic disinfection of environmental surfaces contaminated by meticillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Petti, S; Messano, G A

    2016-05-01

    Traditional cleaning and disinfection methods are inefficient for complete decontamination of hospital surfaces from meticillin-resistant Staphylococcus aureus (MRSA). Additional methods, such as nano-TiO2-based photocatalytic disinfection (PCD), could be helpful. To evaluate anti-MRSA activity of PCD on polyvinyl chloride (PVC) surfaces in natural-like conditions. Two identical PVC surfaces were used, and nano-TiO2 was incorporated into one of them. The surfaces were contaminated with MRSA isolated from hospitalized patients using a mist sprayer to simulate the mode of environmental contamination caused by a carrier. MRSA cell density was assessed before contamination until 180min after contamination using Rodac plates. The differences between test and control surfaces in terms of MRSA density and log MRSA density reduction were assessed using parametric and non-parametric statistical tests. Five strains were tested, and each strain was tested five times. The highest median MRSA densities [46.3 and 43.1 colony-forming units (cfu)/cm(2) for control and test surfaces, respectively] were detected 45min after contamination. Median MRSA densities 180min after contamination were 10.1 and 0.7cfu/cm(2) for control and test surfaces, respectively (Pdisinfectant activity remained stable throughout the 25 testing occasions, despite between-test cleaning and disinfection. The anti-MRSA activity of PCD was compatible with the benchmark for surface hygiene in hospitals (surfaces. However, for clinical surfaces, PCD should be regarded as supplemental to conventional decontamination procedures, rather than an alternative. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  4. Heavy metal contamination in surface sediments of Yangtze River intertidal zone: An assessment from different indexes

    International Nuclear Information System (INIS)

    Zhang Weiguo; Feng Huan; Chang Jinna; Qu Jianguo; Xie Hongxia; Yu Lizhong

    2009-01-01

    Surface sediments (0-5 cm) from 59 stations within the Yangtze River intertidal zone (YRIZ) were sampled for metal contamination analysis in April and August 2005. The concentrations ranged (in mg kg -1 dry weight): Al, 40,803-97,213; Fe, 20,538-49,627; Cd, 0.12-0.75; Cr, 36.9-173; Cu, 6.87-49.7; Mn, 413-1,112; Ni, 17.6-48.0; Pb, 18.3-44.1; and Zn, 47.6-154; respectively. Among the 59 sampling stations, enrichment factors (EF) indicate enrichment of Cd (52 stations), Cr (54 stations), Cu (5 stations), Ni (26 stations), Pb (5 stations) and Zn (5 stations). Geoaccumulation indexes (I geo ) also suggest individual metal contamination in localized areas. This study indicates that Cd, Cr and Ni enrichment in the YRIZ sediment is widespread whereas Cu, Mn, Pb and Zn enrichment is localized or nonexistent. Factor and cluster analyses indicate that Cd is associated with total organic carbon whereas Cu, Cr, Ni, Pb and Zn have a close association with Mn. - Surface sediment metal enrichment is evidenced for Cd, Cr and Ni in the Yangtze River intertidal zone.

  5. Guidance and methods for satisfying low specific activity material and surface contaminated object regulatory requirements

    International Nuclear Information System (INIS)

    Pope, R.B.; Shappert, L.B.; Michelhaugh, R.D.; Boyle, R.W.; Easton, E.P.; Coodk, J.R.

    1998-01-01

    The U.S. Department of Transportation (DOT) and the U.S. Nuclear Regulatory Commission (NRC) have prepared a comprehensive set of draft guidance for shippers and inspectors to use when applying the newly imposed regulatory requirements for low specific activity (LSA) material and surface contaminated objects (SCOs). These requirements represent significant departures in some areas from the manner in which these materials and objects were regulated by the earlier versions of the regulations. The proper interpretation and application of the regulatory criteria can require a fairly complex set of decisions be made. To assist those trying these regulatory requirements, a detailed set of logic-flow diagrams representing decisions related to multiple factors were prepared and included in the draft report for comment on Categorizing and Transporting Low Specific Activity Materials and Surface Contaminated Objects, (DOT/NRC, 1997). These logic-flow diagrams, as developed, are specific to the U.S. regulations, but were readily adaptable to the IAEA regulations. The diagrams have been modified accordingly and tied directly to specific paragraphs in IAEA Safety Series No. 6. This paper provides the logic-flow diagrams adapted in the IAEA regulations, and demonstrated how these diagrams can be used to assist consignors and inspectors in assessing compliance of shipments with the LSA material and SCO regulatory requirements. (authors)

  6. Aircraft-borne spectrometry - a fast method for nuclide-specific measurement of soil contamination

    International Nuclear Information System (INIS)

    Winkelmann, I.; Schweiger, M.; Thomas, M.; Endrulat, H.J.

    1991-01-01

    An airworthy gamma spectrometer system for fast and large-area, nuclide-specific measurement of the soil contamination is described. The system encompasses an ultrapure germanium detector combined with a computer-controlled multichannel analyser system. The development from the laboratory system to an industrial-scale measuring system is explained. The practical testing is explained and first results are reported, obtained from measuring flights for the nuclide-specific determination of the soil contamination in the free State of Bavaria. (orig.) [de

  7. Evaluation of ATP measurements to detect microbial ingress by wastewater and surface water in drinking water.

    Science.gov (United States)

    Vang, Óluva K; Corfitzen, Charlotte B; Smith, Christian; Albrechtsen, Hans-Jørgen

    2014-11-01

    Fast and reliable methods are required for monitoring of microbial drinking water quality in order to protect public health. Adenosine triphosphate (ATP) was investigated as a potential real-time parameter for detecting microbial ingress in drinking water contaminated with wastewater or surface water. To investigate the ability of the ATP assay in detecting different contamination types, the contaminant was diluted with non-chlorinated drinking water. Wastewater, diluted at 10(4) in drinking water, was detected with the ATP assay, as well as 10(2) to 10(3) times diluted surface water. To improve the performance of the ATP assay in detecting microbial ingress in drinking water, different approaches were investigated, i.e. quantifying microbial ATP or applying reagents of different sensitivities to reduce measurement variations; however, none of these approaches contributed significantly in this respect. Compared to traditional microbiological methods, the ATP assay could detect wastewater and surface water in drinking water to a higher degree than total direct counts (TDCs), while both heterotrophic plate counts (HPC 22 °C and HPC 37 °C) and Colilert-18 (Escherichia coli and coliforms) were more sensitive than the ATP measurements, though with much longer response times. Continuous sampling combined with ATP measurements displays definite monitoring potential for microbial drinking water quality, since microbial ingress in drinking water can be detected in real-time with ATP measurements. The ability of the ATP assay to detect microbial ingress is influenced by both the ATP load from the contaminant itself and the ATP concentration in the specific drinking water. Consequently, a low ATP concentration of the specific drinking water facilitates a better detection of a potential contamination of the water supply with the ATP assay. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. America's Children and the Environment: Measures of Contaminants, Body Burdens, and Illnesses. Second Edition.

    Science.gov (United States)

    Woodruff, Tracey J.; Axelrad, Daniel A.; Kyle, Amy D.; Nweke, Onyemaechi; Miller, Gregory G.

    Noting that children may be affected by environmental contaminants in ways quite different from the way adults are affected, this report is the second on trends in measures reflecting environmental factors that may affect the U.S. children's health and well-being. A list of measures and key findings begins the report, followed by five main…

  9. Evaluation of measures to decrease intra-operative bacterial contamination in orthopaedic implant surgery

    NARCIS (Netherlands)

    Knobben, BAS; van Horn, [No Value; van der Mei, HC; Busscher, HJ

    The aim of this study was to evaluate whether behavioural and systemic measures wilt decrease intra-operative contamination during total hip or knee replacements. The influence of these measures on subsequent prolonged wound discharge, superficial surgical site infection and deep periprosthetic

  10. Hazard Assessment of Chemical Air Contaminants Measured in Residences

    Energy Technology Data Exchange (ETDEWEB)

    Logue, J.M.; McKone, T.E.; Sherman, M. H.; Singer, B.C.

    2010-05-10

    Identifying air pollutants that pose a potential hazard indoors can facilitate exposure mitigation. In this study, we compiled summary results from 77 published studies reporting measurements of chemical pollutants in residences in the United States and in countries with similar lifestyles. These data were used to calculate representative mid-range and upper bound concentrations relevant to chronic exposures for 267 pollutants and representative peak concentrations relevant to acute exposures for 5 activity-associated pollutants. Representative concentrations are compared to available chronic and acute health standards for 97 pollutants. Fifteen pollutants appear to exceed chronic health standards in a large fraction of homes. Nine other pollutants are identified as potential chronic health hazards in a substantial minority of homes and an additional nine are identified as potential hazards in a very small percentage of homes. Nine pollutants are identified as priority hazards based on the robustness of measured concentration data and the fraction of residences that appear to be impacted: acetaldehyde; acrolein; benzene; 1,3-butadiene; 1,4-dichlorobenzene; formaldehyde; naphthalene; nitrogen dioxide; and PM{sub 2.5}. Activity-based emissions are shown to pose potential acute health hazards for PM{sub 2.5}, formaldehyde, CO, chloroform, and NO{sub 2}.

  11. The system for measurements of radioactive contamination of environment and food in Poland

    International Nuclear Information System (INIS)

    Grabowski, D.; Kurowski, W.

    1990-01-01

    The service for Measurements of Radioactive Contamination comprises a network of 152 measuring stations. They are carrying out continuous measurements of gamma radiation dose rates and radioactivity measurements of 24 hours samples of air (aerosols) and total fallout. On the territory of each province there are selected points for sampling of environmental materials and food. Frequency of sampling depends on material being collected. 1 tab., 2 figs. (A.S.)

  12. Detection system qualification for direct measurement of thyroid internal contamination by radioiodine

    International Nuclear Information System (INIS)

    Tiberi, V.; Battisti, P.; Gualdrini, G.

    1999-01-01

    The work deals with a detection system qualification for direct measurements of thyroid internal contamination by radioiodine. The isotopes 131 I and 125 I are the most frequently used in nuclear medicine. Because of their volatility they are very dangerous for thyroid contamination by inhalation. The system has been projected to be easily and fast used and above all transportable where the control is necessary. These characteristic make it able to realise supervision programs of internal contamination by radioiodine. In fact due the very high control frequencies (each 15 days for 131 I), these programs are usually very expensive and demanding when they are executed in external measurement laboratories. The following steps are described: devices presentation, calculation of energy and efficiency parameters, minimum detectable activity, time system reliability, best operative conditions in the measurements. At the end an application example of the system is reported [it

  13. Solutal Marangoni flows of miscible liquids drive transport without surface contamination

    Science.gov (United States)

    Kim, Hyoungsoo; Muller, Koen; Shardt, Orest; Afkhami, Shahriar; Stone, Howard A.

    2017-11-01

    Mixing and spreading of different liquids are omnipresent in nature, life and technology, such as oil pollution on the sea, estuaries, food processing, cosmetic and beverage industries, lab-on-a-chip devices, and polymer processing. However, the mixing and spreading mechanisms for miscible liquids remain poorly characterized. Here, we show that a fully soluble liquid drop deposited on a liquid surface remains as a static lens without immediately spreading and mixing, and simultaneously a Marangoni-driven convective flow is generated, which are counterintuitive results when two liquids have different surface tensions. To understand the dynamics, we develop a theoretical model to predict the finite spreading time and length scales, the Marangoni-driven convection flow speed, and the finite timescale to establish the quasi-steady state for the Marangoni flow. The fundamental understanding of this solutal Marangoni flow may enable driving bulk flows and constructing an effective drug delivery and surface cleaning approach without causing surface contamination by immiscible chemical species.

  14. SUDOQU: a new dose model to derive criteria for surface contamination of non-food (consumer) goods, containers and conveyances

    International Nuclear Information System (INIS)

    Van Dillen, Teun

    2015-01-01

    The Fukushima nuclear accident (Japan, 11 March 2011) revealed the need for well-founded criteria for surface contamination and associated screening levels related to the import of non-food (consumer) goods, containers and conveyances. The only available European-harmonised criteria are those laid down in the IAEA transport regulations, but these criteria date back from the early 1960's and only apply to the safe transport of radioactive materials. The main problem is that a generic dose-assessment model for consumer products is missing. Therefore, RIVM (National Institute for Public Health and the Environment) developed a new methodology entitled SUDOQU (Surface Dose Quantification) to calculate the annual effective dose for both consumers and non-radiological workers, addressing issues of removability of surface contamination. The methodology can be used to derive criteria and screening levels for surface contamination and could serve as a useful tool for policy-makers and radiation-protection specialists. (authors)

  15. MODELING THE ANOMALY OF SURFACE NUMBER DENSITIES OF GALAXIES ON THE GALACTIC EXTINCTION MAP DUE TO THEIR FIR EMISSION CONTAMINATION

    Energy Technology Data Exchange (ETDEWEB)

    Kashiwagi, Toshiya; Suto, Yasushi; Taruya, Atsushi; Yahata, Kazuhiro [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan); Kayo, Issha [Department of Physics, Toho University, Funabashi, Chiba 274-8510 (Japan); Nishimichi, Takahiro, E-mail: kashiwagi@utap.phys.s.u-tokyo.ac.jp [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan)

    2015-02-01

    The most widely used Galactic extinction map is constructed assuming that the observed far-infrared (FIR) fluxes come entirely from Galactic dust. According to the earlier suggestion by Yahata et al., we consider how FIR emission of galaxies affects the SFD map. We first compute the surface number density of Sloan Digital Sky Survey (SDSS) DR7 galaxies as a function of the r-band extinction, A {sub r,} {sub SFD}. We confirm that the surface densities of those galaxies positively correlate with A {sub r,} {sub SFD} for A {sub r,} {sub SFD} < 0.1, as first discovered by Yahata et al. for SDSS DR4 galaxies. Next we construct an analytical model to compute the surface density of galaxies, taking into account the contamination of their FIR emission. We adopt a log-normal probability distribution for the ratio of 100 μm and r-band luminosities of each galaxy, y ≡ (νL){sub 100} {sub μm}/(νL) {sub r}. Then we search for the mean and rms values of y that fit the observed anomaly, using the analytical model. The required values to reproduce the anomaly are roughly consistent with those measured from the stacking analysis of SDSS galaxies. Due to the limitation of our statistical modeling, we are not yet able to remove the FIR contamination of galaxies from the extinction map. Nevertheless, the agreement with the model prediction suggests that the FIR emission of galaxies is mainly responsible for the observed anomaly. Whereas the corresponding systematic error in the Galactic extinction map is 0.1-1 mmag, it is directly correlated with galaxy clustering and thus needs to be carefully examined in precision cosmology.

  16. A DEVICE TO MEASURE LOW LEVELS OF RADIOACTIVE CONTAMINANTS IN ULTRA-CLEAN MATERIALS

    International Nuclear Information System (INIS)

    James H Reeves; Matthew Kauer

    2006-01-01

    detector measuring 6 inch x 6 inch x 6 inch was fitted with wave length shifting fibers that allowed the light from ionizing radiation to be collected and transmitted outside the massive shield to photomultiplier tubes and electronics. The detector was calibrated for energy and detection efficiency and low resolution background spectra were collected. Results from these measurements show the figure of merit (using: efficiency/square root of background) for this plastic scintillation counting technique to be ∼15 times better than for a 2 kg germanium detector for measuring surface contamination from atmospheric 222Rn daughters (210Pb, 210Bi, and 210Po). These daughter radionuclides are normally deposited everywhere onto all materials exposed to air. The results are encouraging and indicate that plastic scintillation counting techniques can be of benefit to the public by making available very sensitive counters for screening ultra-low background materials at an affordable cost. However, in order to reach the level required a multi element array of thin plastic scintillator sheets must be developed that will allow many thin samples to be counted at one time. In addition, more sophisticated light detection hardware, electronics, and computer software is needed

  17. Beta Autoradiography. An analytical technique to investigate radionuclides contamination on surface

    International Nuclear Information System (INIS)

    Ficher, P.; Goutelard, F.; Siitari-Kauppi, M.

    2012-01-01

    In decommissioning of old buildings and after disposal of nuclear facilities (materials, glove boxes,...), the inventory of the radioactive contamination of various building materials needs to be obtained in order to fix the working condition for dismantling. The challenge of this study was to classify different building materials of a whole research laboratory that was dedicated to research on organic molecules labeled with H-3 and C-14. The problem of waste classification is essential for safety treatment of waste and also for its cost. The analytical technique of beta autoradiography particularly well known for biological researches has been tested to investigate radionuclides contamination on surface. This technique is mainly interesting for beta and alpha emitters but also sensitive to gamma radiation. The first step of this technique is the deposit of a film on the surface of material to be analyzed. Films can be deposited on the ground or also fixed on the walls or even on the ceiling. The film is a plastic sheet covered with an emulsion containing photostimulable crystals and Eu that is activated when the film is exposed on radioactive source. The exposed films are then scanned with the Cyclone Plus equipment to get a digitized image. This image represents the radioactivity of the surface studied. The possibility to re-use the films is very important to investigate a large area. This autoradiography technique has retained our attention for its sensitivity and moreover the possibility of 2-dimensional investigation has been found as a real advantage. However it remains now as a qualitative technique and new studies must be launched to prove its quantitative potentialities. The high spatial resolution was not as important as in biological observation, and the mm resolution is totally sufficient

  18. Environmental Measurement While Drilling System for Real-Time Field Screening of Contaminants

    International Nuclear Information System (INIS)

    Lockwood, G.J.; Normann, R.A.; Williams, C.V.

    1999-01-01

    Sampling during environmental drilling is essential to fully characterize the spatial distribution and migration of subsurface contaminants. However, analysis of the samples is expensive and time-consuming: off-site laboratory analysis can take weeks or months. Real-time information on environmental conditions, drill bit location and temperature during drilling is valuable in many environmental restoration operations. This type of information can be used to provide field screening data and improved efficiency of site characterization activities. The Environmental Measurement-While-Drilling (EMWD) System represents an innovative blending of new and existing technology in order to obtain real-time data during drilling. The system consists of two subsystems. The down-hole subsystem (at the drill bit) consists of sensors, a power supply, a signal conditioning and transmitter board, and a radio-frequency (RF) coaxial cable. The up-hole subsystem consists of a battery pack/coil, pickup coil, receiver, and personal computer. The system is compatible with fluid miser drill pipe, a directional drilling technique that uses minimal drilling fluids and generates little to no secondary waste. In EMWD, downhole sensors are located behind the drill bit and linked by a high-speed data transmission system to a computer at the surface. Sandia-developed Windowstrademark-based software is used for data display and storage. As drilling is conducted, data is collected on the nature and extent of contamination, enabling on-the-spot decisions regarding drilling and sampling strategies. Initially, the downhole sensor consisted of a simple gamma radiation detector, a Geiger-Mueller tube (GMT). The design includes data assurance techniques to increase safety by reducing the probability of giving a safe indication when an unsafe condition exists. The EMWD system has been improved by the integration of a Gamma Ray Spectrometer (GRS) in place of the GMT. The GRS consists of a sodium iodide

  19. Measurement of contaminant removal from skin using a portable fluorescence scanning system

    International Nuclear Information System (INIS)

    Hession, Helena; Byrne, Miriam; Cleary, S.; Andersson, K.G.; Roed, J.

    2006-01-01

    The residence time of particulate contamination on the human body is a factor that has an important impact on the accuracy of exposure assessment in the aftermath of an accidental release of radionuclides to the atmosphere. Measurements of particle clearance from human skin were made using an illumination system to excite fluorescence in labelled silica particles and a CCD camera and image processing system to detect this fluorescence. The illumination system consists of high-intensity light emitting diodes (LEDS) of suitable wavelengths arranged on a portable stand. The physically small size of the LEDs allows them to be positioned close to the fluorescing surface, thus maximising the fluorescent signal that can be obtained. The limit of detection was found to be 50 μg of tracer particle per cm 2 . Experiments were carried out to determine the clearance rates of 10 μm and 3 μm particles from the skin. Results show that, in the absence of any mechanical rubbing of the skin, the clearance of particles from the skin followed an approximately exponential decay with a half-time of 1.5-7.8 h. Skin hairiness and degree of human movement were found, in addition to particle size, to have an important influence on particle fall-off rate

  20. A study on EUV reticle surface molecular contamination under different storage conditions in a HVM foundry fab

    Science.gov (United States)

    Singh, SherJang; Yatzor, Brett; Taylor, Ron; Wood, Obert; Mangat, Pawitter

    2017-03-01

    The prospect of EUVL (Extreme Ultraviolet Lithography) insertion into HVM (High Volume Manufacturing) has never been this promising. As technology is prepared for "lab to fab" transition, it becomes important to comprehend challenges associated with integrating EUVL infrastructure within existing high volume chip fabrication processes in a foundry fab. The existing 193nm optical lithography process flow for reticle handling and storage in a fab atmosphere is well established and in-fab reticle contamination concerns are mitigated with the reticle pellicle. However EUVL reticle pellicle is still under development and if available, may only provide protection against particles but not molecular contamination. HVM fab atmosphere is known to be contaminated with trace amounts of AMC's (Atmospheric Molecular Contamination). If such contaminants are organic in nature and get absorbed on the reticle surface, EUV photon cause photo-dissociation resulting into carbon generation which is known to reduce multilayer reflectivity and also degrades exposure uniformity. Chemical diffusion and aggregation of other ions is also reported under the e-beam exposure of a EUV reticle which is known to cause haze issues in optical lithography. Therefore it becomes paramount to mitigate absorbed molecular contaminant concerns on EUVL reticle surface. In this paper, we have studied types of molecular contaminants that are absorbed on an EUVL reticle surface under HVM fab storage and handling conditions. Effect of storage conditions (gas purged vs atmospheric) in different storage pods (Dual pods, Reticle Clamshells) is evaluated. Absorption analysis is done both on ruthenium capping layer as well as TaBN absorber. Ru surface chemistry change as a result of storage is also studied. The efficacy of different reticle cleaning processes to remove absorbed contaminant is evaluated as well.

  1. Measurement in vivo of the cutaneous contamination provoked by a radioactive solution

    International Nuclear Information System (INIS)

    Lefaix, J.L.; Lombardo, J.; Delacroix, D.

    1996-01-01

    The utilization of unsealed radioactive sources may cause cutaneous contamination accidents. The detriment is function of the dose of irradiation absorbed by the basal layer of the epidermis and mainly depends on the energy of the β rays, the molecular nature of contaminant and the time of contact with the skin. Furthermore, the penetration kinetic of a substance through the skin is influenced by different factors. So as to determine the dose of irradiation absorbed by the basal layer of the epidermis, we have realized different studies of cutaneous contamination in vivo in the pig: in a first study wa have compared cutaneous obsorption of a radioisotope ( 99m TC) diluted in physiological serum, in a aprotic solvent (DMSO) known to enhance the cutaneous permeability, and by varying the pH of the solution. In a second part, we have compared the cutaneous absorption after contamination times of 1 and 5 minutes, and in different hydration states of the skin before contamination. Results of the in vivo cutaneous absorption, for contaminating times of 1 and 5 minutes, have shown a loss of 5 % of external counting of the electrons (external counting of the 120 KeV electron of 99m Tc), one hour after the contamination, for all the chemical vectors. The variation of the contamination time and the state of hydration of the skin before contamination showed similar results. From these experimental results, an exponential distribution model of the radioisotope in the skin has allowed to calculate the dose rate equivalent of irradiation absorbed by the basal layer of the ipidermis: during a contamination of 5 minutes on a surface of 9 cm 2 with 99m Tc, this dose rate equivalent was 0.98 mSv h -1 by 37 kBq cm -2 (μCi cm -2 ). By the Monte-Carlo method in the hypothesis where there is no cutaneous absorption, it was 0.94 mSv h -1 by 37 kBq cm-2. A preliminary experience with a β emitter ( 14 C) has confirmed a less of 5% of the counting in the same experimental conditions

  2. The groundwater contribution to surface water contamination in a region with intensive agricultural land use (Noord-Brabant, The Netherlands)

    International Nuclear Information System (INIS)

    Rozemeijer, J.C.; Broers, H.P.

    2007-01-01

    Traditionally, monitoring of soil, groundwater and surface water quality is coordinated by different authorities in the Netherlands. Nowadays, the European Water Framework Directive (EU, 2000) stimulates an integrated approach of the complete soil-groundwater-surface water system. Based on water quality data from several test catchments, we propose a conceptual model stating that stream water quality at different discharges is the result of different mixing ratios of groundwater from different depths. This concept is used for a regional study of the groundwater contribution to surface water contamination in the Dutch province of Noord-Brabant, using the large amount of available data from the regional monitoring networks. The results show that groundwater is a dominant source of surface water contamination. The poor chemical condition of upper and shallow groundwater leads to exceedance of the quality standards in receiving surface waters, especially during quick flow periods. - Water quality monitoring data show the importance of the groundwater contribution to surface water pollution

  3. Decontamination effects of a simulated contaminated floor surface by a teleoperated mopping system

    International Nuclear Information System (INIS)

    Kim, Ki Ho; Kwon, Hyok Jo; Park, Jang Jin; Yang, Myung Seung

    2004-01-01

    A Tele Operated Mopping System (TOMS) was developed for use in the radioactive zone of the M6 hot-cell of the Irradiated Material Examination Facility (IMEF) at the Korea Atomic Energy Research Institute (KAERI). TOMS was designed to remove contaminated dry particulates, dust, and smears existing on the floor surface of the M6 hot-cell by mopping it in a remote manner. TOMS has three subsystems - a mobile mopping slave located inside the hot-cell, and a mopping master and a control console located outside the hot-cell. The mobile mopping slave consists of a tracked mobile platform, a mopping tool, and a wet mopping cloth, which were constructed in modules to facilitate a maintenance. This paper aims at describing the mopping capability of the developed TOMS - decontamination capability. In this work the decontamination capability is defined by the ratio of the removed contaminated area when the mopping cloth was passed over. The experiment was carried out by varying the speeds of the mopping slave and the roller, while the mopping force driven by the operator was constant. The roller of the mopping tool mounted on the mopping slave was designed to collect the mopping cloth used. The experimental results showed that the speeds of the mopping slave and the roller influence the extent of the decontamination

  4. Dispersion of inorganic contaminants in surface water in the vicinity of Potchefstroom

    Science.gov (United States)

    Manyatshe, A.; Fosso-Kankeu, E.; van der Berg, D.; Lemmer, N.; Waanders, F.; Tutu, H.

    2017-08-01

    Potchefstroom and the neighbouring cities rely mostly on the Mooi River and Vaal River for their water needs. These rivers flow through the gold mining areas and farms, and are therefore likely to be contaminated with substantial amounts of inorganic pollutants. Water was collected along the rivers network, streams, canals and dams in Potchefstroom and the vicinity. The samples were characterized for geochemical parameters, metals and anions concentrations. The results showed high concentrations of potentially toxic elements such as As (4.53 mg/L - 5.74 mg/L), Cd (0.25 mg/L - 0.7 mg/L), Pb (1.14 mg/L - 5.13 mg/L) and U (0.04 mg/L - 0.11 mg/L) which were predominantly found around the mining areas. Elevated concentrations of anions such SO42- and CN- were detected around mining areas while NO3- was dominant near farms. The relatively high levels of anions and metals in the surface water made it unfit for domestic or agricultural use. The study showed that contaminants in mining and agricultural facilities were potentially mobilised, thus impacting the nearby water systems.

  5. Soil and groundwater VOCs contamination: How can electrical geophysical measurements help assess post-bioremediation state?

    Science.gov (United States)

    Kessouri, P.; Johnson, T. C.; Day-Lewis, F. D.; Slater, L. D.; Ntarlagiannis, D.; Johnson, C. D.

    2016-12-01

    The former Brandywine MD (Maryland, USA) Defense Reutilization and Marketing Office (DRMO) was designated a hazardous waste Superfund site in 1999. The site was used as a storage area for waste and excess government equipment generated by several U.S. Navy and U.S. Air Force installations, leading to soil and groundwater contamination by volatile organic compounds (VOCs). Active bioremediation through anaerobic reductive dehalogenation was used to treat the groundwater and the aquifer unconsolidated materials in 2008, with electrical geophysical measurements employed to track amendment injections. Eight years later, we used spectral induced polarization (SIP) and time domain induced polarization (TDIP) on 2D surface lines and borehole electrical arrays to assess the long term impact of active remediation on physicochemical properties of the subsurface. Within the aquifer, the treated zone is more electrically conductive, and the phase shift describing the polarization effects is higher than in the untreated zone. Bulk conductivity and phase shift are also locally elevated close to the treatment injection well, possibly due to biogeochemical transformations associated with prolonged bacterial activity. Observed SIP variations could be explained by the presence of biofilms coating the pore space and/or by-products of the chemical reactions catalyzed by the bacterial activity (e.g. iron sulfide precipitation). To investigate these possibilities, we conducted complementary well logging measurements (magnetic susceptibility [MS], nuclear magnetic resonance [NMR], gamma-ray) using 5 boreholes installed at both treated and untreated locations of the site. We also collected water and soil samples on which we conducted microbiological and chemical analyses, along with geophysical observations (SIP, MS and NMR), in the laboratory. These measurements provide further insights into the physicochemical transformations in the subsurface resulting from the treatment and highlight

  6. Means to remove electrode contamination effect of Langmuir probe measurement in space

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, K.-I.; Lee, C. H.; Fang, H. K.; Cheng, C. Z. [Plasma and Space Science Center, National Cheng Kung University, No.1 Ta-Hsueh Rd., Tainan 70101, Taiwan (China)

    2012-05-15

    Precaution to remove the serious effect of electrode contamination in Langmuir probe experiments has not been taken in many space measurements because the effect is either not understood or ignored. We stress here that one should pay extra attention to the electrode contamination effect to get accurate and reliable plasma measurements so that the long time effort for sounding rocket/satellite missions does not end in vain or becomes less fruitful. In this paper, we describe two main features of voltage-current characteristic curves associated with the contaminated Langmuir probe, which are predicted from the equivalent circuit model, which we proposed in 1970's. We then show that fast sweeping dc Langmuir probes can give reliable results in the steady state regime. The fast sweeping probe can also give reliable results in transient situations such as satellite moves through plasma bubble in the ionosphere where the electron density drastically changes. This fact was first confirmed in our laboratory experiment.

  7. Multicenter evaluation of a new closed system drug-transfer device in reducing surface contamination by antineoplastic hazardous drugs.

    Science.gov (United States)

    Bartel, Sylvia B; Tyler, Timothy G; Power, Luci A

    2018-02-15

    Results of a study to evaluate the effectiveness of a recently introduced closed system drug-transfer device (CSTD) in reducing surface contamination during compounding and simulated administration of antineoplastic hazardous drugs (AHDs) are reported. Wipe samples were collected from 6 predetermined surfaces in compounding and infusion areas of 13 U.S. cancer centers to establish preexisting levels of surface contamination by 2 marker AHDs (cyclophosphamide and fluorouracil). Stainless steel templates were placed over the 6 previously sampled surfaces, and the marker drugs were compounded and infused per a specific protocol using all components of the CSTD. Wipe samples were collected from the templates after completion of tasks and analyzed for both marker AHDs. Aggregated results of wipe sampling to detect preexisting contamination at the 13 study sites showed that overall, 66.7% of samples (104 of 156) had detectable levels of at least 1 marker AHD; subsequent testing after CSTD use per protocol found a sample contamination rate of 5.8% (9 of 156 samples). In the administration areas alone, the rate of preexisting contamination was 78% (61 of 78 samples); with use of the CSTD protocol, the contamination rate was 2.6%. Twenty-six participants rated the CSTD for ease of use, with 100% indicating that they were satisfied or extremely satisfied. A study involving a rigorous protocol and 13 cancer centers across the United States demonstrated that the CSTD reduced surface contamination by cyclophosphamide and fluorouracil during compounding and simulated administration. Participants reported that the CSTD was easy to use. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  8. Laser-induced damage of fused silica at 355 and 1065 nm initiated at aluminum contamination particles on the surface

    International Nuclear Information System (INIS)

    Genin, F.Y.; Michlitsch, K.; Furr, J.; Kozlowski, M.R.; Krulevitch, P.

    1997-01-01

    1-μm thick circular dots, 10-250 μm dia, were deposited onto 1.14 cm thick fused silica windows by sputtering Al through a mask. Al shavings were also deposited on the windows to investigate effects of particle-substrate adhesion. The silica windows were then illuminated repetitively using a 3-ns, 355 nm and an 8.6-ns, 1064 nm laser. The tests were conducted at near normal incidence with particles on input and output surfaces of the windows. During the first shot, a plasma ignited at the metal particle and damage initiated on the fused silica surface. The morphology of the damage at the metal dots were reproducible but different for input and output surface contamination. For input surface contamination, minor damage occurred where the particle was located; such damage ceased to grow with the removal of contaminant material. More serious damage (pits and cracks) was initiated on the output surface (especially at 355 nm) and grew to catastrophic proportions after few shots. Output surface contaminants were usually ejected on the initial shot, leaving a wave pattern on the surface. No further damage occurred with subsequent shots unless a shot (usually the first shot) cracked the surface; such behavior was mostly observed at 355 nm and occasionally for large shavings at 1064 nm. The size of the damaged area scaled with the size of the particle (except when catastrophic damage occurred). Onset of catastrophic damage on output surface occurred only when particles exceeded a critical size. Damage behavior of the sputtered dots was found to be qualitatively similar to that of the shavings. The artificial contamination technique accelerated the study by allowing better control of the test conditions

  9. Agricultural contamination in soil-groundwater-surface water systems in the North China Plain

    DEFF Research Database (Denmark)

    Brauns, Bentje

    of fertilizers and pesticides. Unfortunately, the lack of regulation or oversight has led to the overuse of these agrochemicals: current application rates (in kg/ha) are two- to threefold higher than in most developed countries, and this is taking its toll on the environment. Problems include severe surface...... water and groundwater pollution by nitrogen and pesticides, soil degradation, bioaccumulation of toxic compounds, and more. It is crucial for China to do improve the safeguarding of its water resources in order to sustain the livelihoods of its people and ensure safe supply of drinking water. Recently......-groundwater interaction was chosen, and field work was performed between October 2012 and March 2014. Results from the field study showed that fertilizer inputs were excessive, and could be reduced substantially. Contaminated river water was infiltrating – and carrying ammonium pollution – into the shallow groundwater...

  10. Risk assessing heavy metals in the groundwater-surface water interface at a contaminated site

    DEFF Research Database (Denmark)

    Bigi, Giovanni; McKnight, Ursula S.; Bjerg, Poul Løgstrup

    such as surface water and groundwater (EC, 2017). The current study quantified and assessed the contamination of As, Cd, Cr, Cu, Ni, Pb and Zn in the shallow aquifer, hyporheic zone, stream water and streambed sediments at Rådvad site, a former metal manufacturing industrial area located in Denmark, investigating...... in the soil). Stream water was sampled in 12 points, while groundwater was sampled in 4 wells close to the stream where the interaction was suspected. Sediments and hyporheic zone were sampled in pair, where upward hydraulic heads have been detected. A drain discharging in the river was also sampled....... Sediments were divided in different layers and both heavy metal total concentration and chemical partitioning were analysed. Redox species and dissolved organic matter were also analysed in the water samples, while fraction of organic carbon was investigated in the extracted sediments. Results showed a high...

  11. The prediction of BRDFs from surface profile measurements

    International Nuclear Information System (INIS)

    Church, E.L.; Takacs, P.Z.; Leonard, T.A.

    1989-01-01

    This paper discusses methods of predicting the BRDF of smooth surfaces from profile measurements of their surface finish. The conversion of optical profile data to the BRDF at the same wavelength is essentially independent of scattering models, while the conversion of mechanical measurements, and wavelength scaling in general, are model dependent. Procedures are illustrated for several surfaces, including two from the recent HeNe BRDF round robin, and results are compared with measured data. Reasonable agreement is found except for surfaces which involve significant scattering from isolated surface defects which are poorly sampled in the profile data

  12. A new fiber optic sensor for inner surface roughness measurement

    Science.gov (United States)

    Xu, Xiaomei; Liu, Shoubin; Hu, Hong

    2009-11-01

    In order to measure inner surface roughness of small holes nondestructively, a new fiber optic sensor is researched and developed. Firstly, a new model for surface roughness measurement is proposed, which is based on intensity-modulated fiber optic sensors and scattering modeling of rough surfaces. Secondly, a fiber optical measurement system is designed and set up. Under the help of new techniques, the fiber optic sensor can be miniaturized. Furthermore, the use of micro prism makes the light turn 90 degree, so the inner side surface roughness of small holes can be measured. Thirdly, the fiber optic sensor is gauged by standard surface roughness specimens, and a series of measurement experiments have been done. The measurement results are compared with those obtained by TR220 Surface Roughness Instrument and Form Talysurf Laser 635, and validity of the developed fiber optic sensor is verified. Finally, precision and influence factors of the fiber optic sensor are analyzed.

  13. Space Flight Experiments to Measure Polymer Erosion and Contamination on Spacecraft

    Science.gov (United States)

    Lillis, Maura C.; Youngstrom, Erica E.; Marx, Laura M.; Hammerstrom, Anne M.; Finefrock, Katherine D.; Youngstrom, Christiane A.; Kaminski, Carolyn; Fine, Elizabeth S.; Hunt, Patricia K.; deGroh, Kim K.

    2002-01-01

    Atomic oxygen erosion and silicone contamination are serious issues that could damage or destroy spacecraft components after orbiting for an extended period of time, such as on a space station or satellite. An experiment, the Polymer Erosion And Contamination Experiment (PEACE) will be conducted to study the effects of atomic oxygen (AO) erosion and silicone contamination, and it will provide information and contribute to a solution for these problems. PEACE will fly 43 different polymer materials that will be analyzed for AO erosion effects through two techniques: mass loss measurement and recession depth measurement. Pinhole cameras will provide information about the arrival direction of AO, and silicone contamination pinhole cameras will identify the source of silicone contamination on a spacecraft. All experimental hardware will be passively exposed to AO for up to two weeks in the actual space environment when it flies in the bay of a space shuttle. A second set of the PEACE Polymers is being exposed to the space environment for erosion yield determination as part of a second experiment, Materials International Space Station Experiment (MISSE). MISSE is a collaboration between several federal agencies and aerospace companies. During a space walk on August 16, 2001, MISSE was attached to the outside of the International Space Station (ISS) during an extravehicular activity (EVA), where it began its exposure to AO for approximately 1.5 years. The PEACE polymers, therefore, will be analyzed after both short-term and long-term AO exposures for a more complete study of AO effects.

  14. Radioactivity measurement of radioactive contaminated soil by using a fiber-optic radiation sensor

    Science.gov (United States)

    Joo, Hanyoung; Kim, Rinah; Moon, Joo Hyun

    2016-06-01

    A fiber-optic radiation sensor (FORS) was developed to measure the gamma radiation from radioactive contaminated soil. The FORS was fabricated using an inorganic scintillator (Lu,Y)2SiO5:Ce (LYSO:Ce), a mixture of epoxy resin and hardener, aluminum foil, and a plastic optical fiber. Before its real application, the FORS was tested to determine if it performed adequately. The test result showed that the measurements by the FORS adequately followed the theoretically estimated values. Then, the FORS was applied to measure the gamma radiation from radioactive contaminated soil. For comparison, a commercial radiation detector was also applied to measure the same soil samples. The measurement data were analyzed by using a statistical parameter, the critical level to determine if net radioactivity statistically different from background was present in the soil sample. The analysis showed that the soil sample had radioactivity distinguishable from background.

  15. Mechanisms for surface contamination of soils and bottom sediments in the Shagan River zone within former Semipalatinsk Nuclear Test Site.

    Science.gov (United States)

    Aidarkhanov, A O; Lukashenko, S N; Lyakhova, O N; Subbotin, S B; Yakovenko, Yu Yu; Genova, S V; Aidarkhanova, A K

    2013-10-01

    The Shagan River is the only surface watercourse within the former Semipalatinsk Test Site (STS). Research in the valley of the Shagan River was carried out to study the possible migration of artificial radionuclides with surface waters over considerable distances, with the possibility these radionuclides may have entered the Irtysh River. The investigations revealed that radioactive contamination of soil was primarily caused by the first underground nuclear test with soil outburst conducted at the "Balapan" site in Borehole 1004. The surface nuclear tests carried out at the "Experimental Field" site and global fallout made insignificant contributions to contamination. The most polluted is the area in the immediate vicinity of the "Atomic" Lake crater. Contamination at the site is spatial. The total area of contamination is limited to 10-12 km from the crater piles. The ratio of plutonium isotopes was useful to determine the source of soil contamination. There was virtual absence of artificial radionuclide migration with surface waters, and possible cross-border transfer of radionuclides with the waters of Shagan and Irtysh rivers was not confirmed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Effects of (α,n) contaminants and sample multiplication on statistical neutron correlation measurements

    International Nuclear Information System (INIS)

    Dowdy, E.J.; Hansen, G.E.; Robba, A.A.; Pratt, J.C.

    1980-01-01

    The complete formalism for the use of statistical neutron fluctuation measurements for the nondestructive assay of fissionable materials has been developed. This formalism includes the effect of detector deadtime, neutron multiplicity, random neutron pulse contributions from (α,n) contaminants in the sample, and the sample multiplication of both fission-related and background neutrons

  17. Inspection of freeform surfaces considering uncertainties in measurement, localization and surface reconstruction

    International Nuclear Information System (INIS)

    Mehrad, Vahid; Xue, Deyi; Gu, Peihua

    2013-01-01

    Inspection of a manufactured freeform surface can be conducted by building its surface model and comparing this manufactured surface model with the ideal design surface model and its tolerance requirement. The manufactured freeform surface model is usually achieved by obtaining measurement points on the manufactured surface, transforming these measurement points from the measurement coordinate system to the design coordinate system through localization, and reconstructing the surface model using the localized measurement points. In this research, a method was developed to estimate the locations and their variances of any selected points on the reconstructed freeform surface considering different sources of uncertainties in measurement, localization and surface reconstruction processes. In this method, first locations and variances of the localized measurement points are calculated considering uncertainties of the measurement points and uncertainties introduced in the localization processes. Then locations and variances of points on the reconstructed freeform surface are obtained considering uncertainties of the localized measurement points and uncertainties introduced in the freeform surface reconstruction process. Two case studies were developed to demonstrate how these three different uncertainty sources influence the quality of the reconstructed freeform curve and freeform surface in inspection. (paper)

  18. Energy distribution and quantum yield for photoemission from air-contaminated gold surfaces under ultraviolet illumination close to the threshold

    Science.gov (United States)

    Hechenblaikner, Gerald; Ziegler, Tobias; Biswas, Indro; Seibel, Christoph; Schulze, Mathias; Brandt, Nico; Schöll, Achim; Bergner, Patrick; Reinert, Friedrich T.

    2012-06-01

    The kinetic energy distributions of photo-electrons emitted from gold surfaces under illumination by UV-light close to the threshold (photon energy in the order of the material work function) are measured and analyzed. Samples are prepared as chemically clean through Ar-ion sputtering and then exposed to atmosphere for variable durations before quantum yield measurements are performed after evacuation. During measurements, the bias voltage applied to the sample is varied and the resulting emission current measured. Taking the derivative of the current-voltage curve yields the energy distribution which is found to closely resemble the distribution of total energies derived by DuBridge for emission from a free electron gas. We investigate the dependence of distribution shape and width on electrode geometry and contaminant substances adsorbed from the atmosphere, in particular, to water and hydro-carbons. Emission efficiency increases initially during air exposure before diminishing to zero on a timescale of several hours, whilst subsequent annealing of the sample restores emissivity. A model fit function, in good quantitative agreement with the measured data, is introduced which accounts for the experiment-specific electrode geometry and an energy dependent transmission coefficient. The impact of large patch potential fields from contact potential drops between sample and sample holder is investigated. The total quantum yield is split into bulk and surface contributions which are tested for their sensitivity to light incidence angle and polarization. Our results are directly applicable to model parameters for the contact-free discharge system onboard the Laser Interferometer Space Antenna (LISA) Pathfinder spacecraft.

  19. Microbial interactions with organic contaminants in soil: Definitions, processes and measurement

    International Nuclear Information System (INIS)

    Semple, Kirk T.; Doick, Kieron J.; Wick, Lukas Y.; Harms, Hauke

    2007-01-01

    There has been and continues to be considerable scientific interest in predicting bioremediation rates and endpoints. This requires the development of chemical techniques capable of reliably predicting the bioavailability of organic compounds to catabolically active soil microbes. A major issue in understanding the link between chemical extraction and bioavailability is the problem of definition; there are numerous definitions, of varying degrees of complexity and relevance, to the interaction between organic contaminants and microorganisms in soil. The aim of this review is to consider the bioavailability as a descriptor for the rate and extent of biodegradation and, in an applied sense, bioremediation of organic contaminants in soil. To address this, the review will (i) consider and clarify the numerous definitions of bioavailability and discuss the usefulness of the term 'bioaccessibility'; (ii) relate definition to the microbiological and chemical measurement of organic contaminants' bioavailability in soil, and (iii) explore the mechanisms employed by soil microorganisms to attack organic contaminants in soil. - Understanding organic contaminant's behaviour in soil is key to chemically predicting biodegradation

  20. Constructing Invariant Fairness Measures for Surfaces

    DEFF Research Database (Denmark)

    Gravesen, Jens; Ungstrup, Michael

    1998-01-01

    of the size of this vector field is used as the fairness measure on the family.Six basic 3rd order invariants satisfying two quadratic equations are defined. They form a complete set in the sense that any invariant 3rd order function can be written as a function of the six basic invariants together...

  1. Surface magnetic field measurement with magnetic shielding

    Czech Academy of Sciences Publication Activity Database

    Perevertov, Oleksiy

    2010-01-01

    Roč. 61, č. 7 (2010), 66-68 ISSN 1335-3632 Grant - others:AVČR(CZ) M100100906 Institutional research plan: CEZ:AV0Z10100520 Keywords : magnetic hysteresis * magnetic field measurement * magnetic shielding * extrapolation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.270, year: 2010

  2. Applicability of portable spectrometer for activity measurement of contaminated water and soil samples

    International Nuclear Information System (INIS)

    Krishnan, Narayani; Rekha, A.K.; Anilkumar, S.; Sharma, D.N.

    2011-01-01

    The absolute activity measurement is often necessary to assess the impact of radioactivity contamination due to various incidents. Commercially available portable spectrometer cum dose rate meter is used for the identification of radionuclides involved and associated dose rates. In this paper the authors discusses the study carried out on the applicability of portable spectrometer for absolute radioactivity measurements in water and soil matrices. The portable spectrometer and the methodology developed for activity estimation has been used in many insitu applications. (author)

  3. In-line gas chromatographic apparatus for measuring the hydrophobic micropore volume (HMV) and contaminant transformation in mineral micropores

    International Nuclear Information System (INIS)

    Cheng Hefa; Reinhard, Martin

    2010-01-01

    Desorption of hydrophobic organic compounds from micropores is characteristically slow compared to surface adsorption and partitioning. The slow-desorbing mass of a hydrophobic probe molecule can be used to calculate the hydrophobic micropore volume (HMV) of microporous solids. A gas chromatographic apparatus is described that allows characterization of the sorbed mass with respect to the desorption rate. The method is demonstrated using a dealuminated zeolite and an aquifer sand as the model and reference sorbents, respectively, and trichloroethylene (TCE) as the probe molecule. A glass column packed with the microporous sorbent is coupled directly to a gas chromatograph that is equipped with flame ionization and electron capture detectors. Sorption and desorption of TCE on the sorbent was measured by sampling the influent and effluent of the column using a combination of switching and injection valves. For geosorbents, the HMV is quantified based on Gurvitsch's rule from the mass of TCE desorbed at a rate that is characteristic for micropores. Instrumental requirements, design considerations, hardware details, detector calibration, performance, and data analysis are discussed along with applications. The method is novel and complements traditional vacuum gravimetric and piezometric techniques, which quantify the total pore volume under vacuum conditions. The HMV is more relevant than the total micropore volume for predicting the fate and transport of organic contaminants in the subsurface. Sorption in hydrophobic micropores strongly impacts the mobility of organic contaminants, and their chemical and biological transformations. The apparatus can serve as a tool for characterizing microprous solids and investigating contaminant-solid interactions.

  4. Tritium surface loading due to contamination of rainwater from atmospheric release at NAPS

    International Nuclear Information System (INIS)

    Sharma, L.N.; Dube, B.; Varakhedkar, V.K.

    2001-01-01

    Annual tritium (HTO) surface loading has been measured and calculated for the year 1998-99 within 0.8 km distance from 145m high stack of Narora Atomic Power Station (NAPS) at eight locations in different directions. The technique for measured values consists of the summation of product of tritium concentration (Bq/l) in daily rainfall samples and daily rainfall (mm) whereas that for calculated values having the use of prevailing meteorological conditions and average tritium release rate during a year. The ratios of measured and calculated values of tritium surface loading during the years 1998-99 are found to be in the range of 0.18 to 6.97. Tritium surface loading studies at NAPS reveal that a fraction 1.7E-03 of total annual tritium released through stack gets deposited on the surface due to washout / rainout of plume within 0.8 km radial distance from stack. The range of deposition velocity, V w (m.s - 1 ) i.e the ratio of annual tritium surface loading W(Bq.m - 2 . s - 1 ) and annual mean tritium concentration in air, χo(Bq.m - 3) at three locations for the years 1998-99 is found to be 5.59E-04 to 5.99E-03 ms - 1 . The average value for wet deposition velocity V bar w for NAPS site is estimated as 2.92E-03 m.s - 1. (author)

  5. Measures against radioactive contamination due to Fukushima First Nuclear Power Plant accidents. Part 3. Removing and decontamination of contaminated soil

    International Nuclear Information System (INIS)

    Ishii, K.; Terakawa, A.; Matsuyama, S.

    2012-01-01

    We studied the structure of radioactive cesium distribution in soil and found the exponential dependence. This behavior could be explained theoretically. We developed a useful method to decontaminate the soil contaminated with radioactive cesium atoms. We applied our method to the contaminated school yards of elementary schools of Marumori town and decontaminated total area of about 7000 m"2. (author)

  6. A prospective survey of air and surface fungal contamination in a medical mycology laboratory at a tertiary care university hospital.

    Science.gov (United States)

    Sautour, Marc; Dalle, Frédéric; Olivieri, Claire; L'ollivier, Coralie; Enderlin, Emilie; Salome, Elsa; Chovelon, Isabelle; Vagner, Odile; Sixt, Nathalie; Fricker-Pap, Véronique; Aho, Serge; Fontaneau, Olivier; Cachia, Claire; Bonnin, Alain

    2009-04-01

    Invasive filamentous fungi infections resulting from inhalation of mold conidia pose a major threat in immunocompromised patients. The diagnosis is based on direct smears, cultural symptoms, and culturing fungi. Airborne conidia present in the laboratory environment may cause contamination of cultures, resulting in false-positive diagnosis. Baseline values of fungal contamination in a clinical mycology laboratory have not been determined to date. A 1-year prospective survey of air and surface contamination was conducted in a clinical mycology laboratory during a period when large construction projects were being conducted in the hospital. Air was sampled with a portable air system impactor, and surfaces were sampled with contact Sabouraud agar plates. The collected data allowed the elaboration of Shewhart graphic charts. Mean fungal loads ranged from 2.27 to 4.36 colony forming units (cfu)/m(3) in air and from 0.61 to 1.69 cfu/plate on surfaces. Strict control procedures may limit the level of fungal contamination in a clinical mycology laboratory even in the context of large construction projects at the hospital site. Our data and the resulting Shewhart graphic charts provide baseline values to use when monitoring for inappropriate variations of the fungal contamination in a mycology laboratory as part of a quality assurance program. This is critical to the appropriate management of the fungal risk in hematology, cancer and transplantation patients.

  7. Heavy metals in the surface sediments of the northern portion of the South China Sea shelf: distribution, contamination, and sources.

    Science.gov (United States)

    Xu, Fangjian; Tian, Xu; Yin, Feng; Zhao, Yongfang; Yin, Xuebo

    2016-05-01

    The concentrations of seven heavy metals (Cr, Ni, Cu, Zn, As, Cd, and Pb) in the surface sediments of the northern portion of the South China Sea (SCS) shelf collected between 2012 and 2014 were measured to assess the potential contamination levels and determine the environmental risks that are associated with heavy metals in the area. The measured concentrations in the sediments were 12.4-72.5 mg kg(-1) for Cr, 4.4-29.2 mg kg(-1) for Ni, 7.1-38.1 mg kg(-1) for Cu, 19.3-92.5 mg kg(-1) for Zn, 1.3-12.1 mg kg(-1) for As, 0.03-0.24 mg kg(-1) for Cd, and 8.5-24.4 mg kg(-1) for Pb. These results indicate that the heavy metal concentrations in the sediments generally meet the China Marine Sediment Quality criteria and suggest that the overall sediment quality of the northern portion of the SCS shelf has not been significantly impacted by heavy metal pollution. However, the enrichment factor (EF) and geoaccumulation index (I geo) clearly show that elevated concentrations of Cd occur in the region. A Pearson's correlation analysis was performed, and the results suggest that Cr, Ni, Cu, and Zn have a natural origin; Cd is primarily sourced from anthropogenic activities, with partial lithogenic components, and As and Pb may be affected by factors such as varying input sources or pathways (i.e., coal burning activities and aerosol precipitation). Heavy metal contamination mostly occurred to the east of Hainan Island, mainly because of the rapid economic and social developments in the Hainan Island. The results of this study will be useful for marine environment managers for the remediation of pollution sources.

  8. Radioactivity Measurements on Glazed Ceramic Surfaces

    OpenAIRE

    Hobbs, Thomas G.

    2000-01-01

    A variety of commonly available household and industrial ceramic items and some specialty glass materials were assayed by alpha pulse counting and ion chamber voltage measurements for radioactivity concentrations. Identification of radionuclides in some of the items was performed by gamma spectroscopy. The samples included tableware, construction tiles and decorative tiles, figurines, and other products with a clay based composition. The concentrations of radioactivity ranged from near backgr...

  9. Grain size measurements by ultrasonic Rayleigh surface waves

    International Nuclear Information System (INIS)

    Palanichamy, P.; Jayakumar, T.

    1996-01-01

    The use of Rayleigh surface waves to determine average grain size nondestructively in an austenitic stainless steel AISI type 316 stainless is discussed. Two commercial type 4MHz frequency surface wave transducers, one as transmitter and the other as receiver were employed for the measurement of surface wave amplitudes. Relative amplitudes of the Rayleigh surface waves were correlated with the metallographically obtained grain sizes. Results indicate that surface/sub-surface average grain sizes of AISI type 316 austenitic stainless steel can be estimated with a confidence level of more than 80% in the grain size range 30-170 μm. (author)

  10. In situ surface roughness measurement using a laser scattering method

    Science.gov (United States)

    Tay, C. J.; Wang, S. H.; Quan, C.; Shang, H. M.

    2003-03-01

    In this paper, the design and development of an optical probe for in situ measurement of surface roughness are discussed. Based on this light scattering principle, the probe which consists of a laser diode, measuring lens and a linear photodiode array, is designed to capture the scattered light from a test surface with a relatively large scattering angle ϕ (=28°). This capability increases the measuring range and enhances repeatability of the results. The coaxial arrangement that incorporates a dual-laser beam and a constant compressed air stream renders the proposed system insensitive to movement or vibration of the test surface as well as surface conditions. Tests were conducted on workpieces which were mounted on a turning machine that operates with different cutting speeds. Test specimens which underwent different machining processes and of different surface finish were also studied. The results obtained demonstrate the feasibility of surface roughness measurement using the proposed method.

  11. Sorption of nonpolar aromatic contaminants by chlorosilane surface modified natural minerals.

    Science.gov (United States)

    Huttenloch, P; Roehl, K E; Czurda, K

    2001-11-01

    The efficacy of the surface modification of natural diatomite and zeolite material by chlorosilanes is demonstrated. Chlorosilanes used were trimethylchlorosilane (TMSCI), tert-butyldimethylchlorosilane (TBDMSCI), dimethyloctadecylchlorosilane (DMODSCI), and diphenyldichlorosilane (DPDSCI) possessing different headgroups and chemical properties. Silanol groups of the diatomite and zeolite were modified by chemical reaction with the chlorosilanes resulting in a stable covalent attachment of the organosilanes to the mineral surface. The alteration of surface properties of the modified material was proved by measurements of water adsorption capacity, total organic carbon (TOC) content, and thermoanalytical data. The surface modified material showed great stability even when exposed to extremes in ionic strength, pH, and to pure organic solvents. Sorption of toluene, o-xylene, and naphthalene from water was greatly enhanced by the surface modification compared to the untreated materials which showed no measurable sorption of these compounds. The enhanced sorption was dependent on the organic carbon content as well as on chemical characteristics of the chlorosilanes used. Batch sorption experiments showed that the phenyl headgroups of DPDSCI have the best affinity for aromatic compounds. Removal from an aqueous solution of 10 mg/L of naphthalene, o-xylene, and toluene was 71%, 60%, and 30% for surface modified diatomite and 51%, 30%, and 16% for modified clinoptilolite, respectively. Sorption data were well described by the Freundlich isotherm equation, which indicated physical adsorption onto the lipophilic surface rather than partitioning into the surface organic phase. The chlorosilane modified materials have an apparent potential for application in environmental technologies such as permeable reactive barriers (PRB) or wastewater treatment.

  12. Identification and quantification of point sources of surface water contamination in fruit culture in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Beltman, W.H.J.; Werd, de H.A.E.; Zande, van de J.C.

    2008-01-01

    Measurements of pesticide concentrations in surface water by the water boards show that they have decreased less than was expected from model calculations. Possibly, the implementation of spray drift reducing techniques is overestimated in the model calculation. The impact of point sources is

  13. Flux Meter Assesses the Effects of Groundwater, Surface Water, and Contaminated Sediment Interactions on Ecosystems

    Science.gov (United States)

    The slow flow of water between groundwater (GW) and surface water (SW) is often referred to as seepage, or in scientific terms, advective flux. This slow flow at the GW/SW interface presents measurement difficulties. This project was conducted to develop a durable advective flux ...

  14. Micro contaminants in surface sediments and macrobenthic invertebrates of the North Sea

    NARCIS (Netherlands)

    Everaarts, J.M.; Fischer, C.V.

    1989-01-01

    Trace metal concentrations (copper, zinc, cadmium and lead) were measured in the silt fraction (grainsize < 63 µm) of surface sediment of the North Sea. The concentrations varied in different areas of the Dutch continental shelf of the North Sea. The trace metal concentrations were highly related

  15. Effect of electron contamination of a 6 MV x-ray beam on near surface diode dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, C R; Mountford, P J; Moloney, A J [Medical Physics Directorate, University Hospital of North Staffordshire, Princes Road, Hartshill, Stoke-on-Trent, Staffordshire, ST4 7LN (United Kingdom)

    2006-12-21

    In critical organ in vivo x-ray dosimetry, the relative contaminating electron contribution to the total dose and total detector response outside the field will be different to the corresponding contributions at the central axis detector calibration position, mainly due to the effects of shielding in the linear accelerator head on the electron and x-ray energy spectrum. To investigate these contributions, the electron energy response of a Scanditronix PFD diode was measured using electrons with mean energies from 0.45 to 14.6 MeV, and the Monte Carlo code MCNP-4C was used to calculate the electron energy spectra on the central axis, and at 1 and 10 cm outside the edge of a 4 x 4, 10 x 10 and a 15 x 15 cm{sup 2} 6 MV x-ray field. The electron contribution to the total dose varied from about 8% on the central axis of the smallest field to about 76% at 10 cm outside the edge of the largest field. The electron contribution to the total diode response varied from about 7-8% on the central axis of all three fields to about 58% at 10 cm outside the edge of the smallest field. The results indicated that a near surface x-ray dose measurement with a diode outside the treatment field has to be interpreted with caution and requires knowledge of the relative electron contribution specific to the measurement position and field size.

  16. Airborne radioactive contamination following aerosol ventilation studies

    International Nuclear Information System (INIS)

    Mackie, A.; Hart, G.C.; Ibbett, D.A.; Whitehead, R.J.S.

    1994-01-01

    Lung aerosol ventilation studies may be accompanied by airborne contamination, with subsequent surface contamination. Airborne contamination has been measured prior to, during and following 59 consecutive 99 Tc m -diethylenetriamine pentaacetate (DTPA) aerosol studies using a personal air sampler. Airborne contamination ranging between 0 and 20 330 kBq m -3 has been measured. Airborne contamination increases with degree of patient breathing difficulty. The effective dose equivalent (EDE) to staff from ingested activity has been calculated to be 0.3 μSv per study. This figure is supported by data from gamma camera images of a contaminated staff member. However, surface contamination measurements reveal that 60% of studies exceed maximum permissible contamination limits for the hands; 16% of studies exceed limits for controlled area surfaces. (author)

  17. Removal factor determination of some local smear papers for surface contamination smear test

    International Nuclear Information System (INIS)

    Suratman; Indriyotomo, D.; Aminjoyo, S.

    1996-01-01

    Removal factor determination of some local smear papers has been done, using dry smear test method. The aim of this research is to find removal values of local smear papers on some surfaces, to replace import smear papers. Smear test was done on the various surfaces i.e.: porcelain, formica, glass, stainless steel, steel and PVC, with the local smear papers I.e.: Padalarang, Diagonal, Concorde, Marga, Hard Cloth, and import smear paper. The artificial contaminant which used were I-131 and P-32. The removal factor values of Padalarang paper for surfaces: porcelain, formica, glass stainless steel, steel and PVC were: 24.5%, 20.0%, 27.0%, 6.8%, 4.9%, and 13.6% respectively. The removal factor values of Diagonal paper were:18.4%, 15.9%, 5.7%, 3.5%, and 9.1% respectively. The removal factor values of concord paper were: 18.5%, 20.3%, 23.1%, 6.6%, 3.8%, and 9.0% respectively. The removal factor values of Marga paper were: 16.7%, 13.5%, 21.1%, 4.2%, 4.1% and 8.1% respectively. The removal factor values of Hard Cloth were: 18.6%, 12.6%, 20.5%, 8.2%, and 10.1% respectively. The removal factor values of import smear paper were: 17.8%, 15.0%, 18.8%, 9.1%, 4.8%, and 14.4% respectively . Substitution alternative of import smear paper is Padalarang. (author)

  18. Surface and borehole electromagnetic imaging of conducting contaminant plumes. 1997 annual progress report

    International Nuclear Information System (INIS)

    Berryman, J.G.

    1997-01-01

    'Electromagnetic induction tomography is a promising new tool for imaging electrical conductivity variations in the earth. The EM source field is produced by induction coil (magnetic dipole) transmitters deployed at the surface or in boreholes. Vertical and horizontal component magnetic field detectors are deployed in other boreholes or on the surface. Sources and receivers are typically deployed in a configuration surrounding the region of interest. The goal of this procedure is to image electrical conductivity variations in the earth, much as x-ray tomography is used to image density variations through cross-sections of the body. Although such EM field techniques have been developed and applied, the algorithms for inverting the magnetic data to produce the desired images of electrical conductivity have not kept pace. One of the main reasons for the lag in the algorithm development has been the fact that the magnetic induction problem is inherently three dimensional: other imaging methods such as x-ray and seismic can make use of two-dimensional approximations that are not too far from reality, but the author does not have this luxury in EM induction tomography. In addition, previous field experiments were conducted at controlled test sites that typically do not have much external noise or extensive surface clutter problems often associated with environmental sites. To use the same field techniques in environments more typical of cleanup sites requires a new set of data processing tools to remove the effects of both noise and clutter. The goal of this project is to join theory and experiment to produce enhanced images of electrically conducting fluids underground, allowing better localization of contaminants and improved planning strategies for the subsequent remediation efforts. After explaining the physical context in more detail, this report will summarize the progress made in the first year of this project: (1) on code development and (2) on field tests of

  19. Performance test and analysis to the prototype of fiber-based portable large area surface contamination monitor

    International Nuclear Information System (INIS)

    Qu Yantao; Liu Yang; Wang Wei; Wang Ying; Hou Jie

    2013-01-01

    The feasibility was studied of using large area plastic scintillation (sensitive area up to 1200 cm 2 ) and wavelength-shifting fiber (WLS) to measure β surface contamination that led to a tentative adoption of direct coupling method of wavelength-shifting fiber array and plastic scintillator. Based on above, a calculation program was established, by which the optical transmission was simulated enabling optimizations to the design of the system such as the size of the plastic scintillator, the quantity of the wavelength-shifting fiber and the configuration mode of the wavelength-shifting fiber. As a result, a special experimental prototype was developed and tested. Results prove that the sensitive detection area is up to 1200 cm 2 , the detection efficiency is about 15.4%, the inconsistency of the different sensitive area is about 9.7%, and the minimum detectable limit is about 0.05 Bq/cm 2 , all of which indicate that the experimental prototype could satisfy requirements of surface pollution monitoring for both normal and accident conditions. (authors)

  20. Hazard and precautionary measures in connection with negligent or wilful contamination

    International Nuclear Information System (INIS)

    Ahlfaenger, Rainer; Scheidegger, Roland

    2009-01-01

    Handling open radioactive substances requires extensive precautionary measures in order to avoid any danger. During the past 100 years many persons were injured or killed due to unintended external irradiation, contamination of the skin or uptake of radioactive substances. With the help of organisational measures with users of sources and with operators of radionuclide laboratories or nuclear installations numerous accidents can be avoided or their consequences can be mitigated. Also the government itself is challenged in order to register and secure radioactive sources and maintaining the national safeguard. Education of personnel handling radioactive substances plays an important role when it comes to precautionary measures. In combination with suitable technical equipment it is possible to obtain a high degree of protection against the hazard from negligent or wilful contamination. (orig.)

  1. Characterization and Remediation of Contaminated Sites:Modeling, Measurement and Assessment

    Science.gov (United States)

    Basu, N. B.; Rao, P. C.; Poyer, I. C.; Christ, J. A.; Zhang, C. Y.; Jawitz, J. W.; Werth, C. J.; Annable, M. D.; Hatfield, K.

    2008-05-01

    The complexity of natural systems makes it impossible to estimate parameters at the required level of spatial and temporal detail. Thus, it becomes necessary to transition from spatially distributed parameters to spatially integrated parameters that are capable of adequately capturing the system dynamics, without always accounting for local process behavior. Contaminant flux across the source control plane is proposed as an integrated metric that captures source behavior and links it to plume dynamics. Contaminant fluxes were measured using an innovative technology, the passive flux meter at field sites contaminated with dense non-aqueous phase liquids or DNAPLs in the US and Australia. Flux distributions were observed to be positively or negatively correlated with the conductivity distribution, depending on the source characteristics of the site. The impact of partial source depletion on the mean contaminant flux and flux architecture was investigated in three-dimensional complex heterogeneous settings using the multiphase transport code UTCHEM and the reactive transport code ISCO3D. Source mass depletion reduced the mean contaminant flux approximately linearly, while the contaminant flux standard deviation reduced proportionally with the mean (i.e., coefficient of variation of flux distribution is constant with time). Similar analysis was performed using data from field sites, and the results confirmed the numerical simulations. The linearity of the mass depletion-flux reduction relationship indicates the ability to design remediation systems that deplete mass to achieve target reduction in source strength. Stability of the flux distribution indicates the ability to characterize the distributions in time once the initial distribution is known. Lagrangian techniques were used to predict contaminant flux behavior during source depletion in terms of the statistics of the hydrodynamic and DNAPL distribution. The advantage of the Lagrangian techniques lies in their

  2. Development of material measures for performance verifying surface topography measuring instruments

    International Nuclear Information System (INIS)

    Leach, Richard; Giusca, Claudiu; Rickens, Kai; Riemer, Oltmann; Rubert, Paul

    2014-01-01

    The development of two irregular-geometry material measures for performance verifying surface topography measuring instruments is described. The material measures are designed to be used to performance verify tactile and optical areal surface topography measuring instruments. The manufacture of the material measures using diamond turning followed by nickel electroforming is described in detail. Measurement results are then obtained using a traceable stylus instrument and a commercial coherence scanning interferometer, and the results are shown to agree to within the measurement uncertainties. The material measures are now commercially available as part of a suite of material measures aimed at the calibration and performance verification of areal surface topography measuring instruments

  3. Listeria monocytogenes contamination of the environment and surfaces of the equipment in the meat processing facilities in republic of Macedonia

    OpenAIRE

    Dean Jankuloski; Pavle Sekulovski; Risto Prodanov; Zehra Hajrulai Musliu; Biljana Stojanovska Dimzovska

    2007-01-01

    Listeria monocytogenes contamination of the environment and surfaces of the equipment was examined in seven meat processing facilities. Up to date prevalence of this foodborn pathogen in meat processing facilities facilities in Republic of Macedonia was unknown. Biofilms are composed from food spoilage microorganisms and food born pathogens. They are located on the surfaces of the equipment that come in contact with food and in facilities environment. Microorganisms in biofilm presenting micr...

  4. MECHANISTIC STUDIES OF SURFACE CATALYZED H2O2 DECOMPOSITION AND CONTAMINANT DEGRADATION IN THE PRESENCE OF SAND. (R823402)

    Science.gov (United States)

    This study examined the mechanism and kinetics of surface catalyzed hydrogen peroxide decomposition and degradation of contaminants in the presence of sand collected from an aquifer and a riverbed. Batch experiments were conducted using variable sand concentrations (0.2 to 1.0&nb...

  5. ''In-situ'' spectro-electrochemical studies of radionuclide-contaminated surface films on metals

    International Nuclear Information System (INIS)

    Melendres, C.A.; Mini, S.; Mansour, A.N.

    2000-01-01

    The incorporation of heavy metal ions and radioactive contaminants into hydrous oxide films has been investigated in order to provide fundamental knowledge that could lead to the technological development of cost-effective processes and techniques for the decontamination of storage tanks, piping systems, surfaces, etc., in DOE nuclear facilities. The formation of oxide/hydroxide films was simulated by electrodeposition onto a graphite substrate from solutions of the appropriate metal salt. Synchrotron X-ray Absorption Spectroscopy (XAS), supplemented by Laser Raman Spectroscopy (LRS), was used to determine the structure and composition of the host oxide film, as well as the impurity ion. Results have been obtained for the incorporation of Ce, Sr, Cr, Fe, and U into hydrous nickel oxide films. Ce and Sr oxides/hydroxides are co-precipitated with the nickel oxides in separate phase domains. Cr and Fe, on the other hand, are able to substitute into Ni lattice sites or intercalate in the interlamellar positions of the brucite structure of Ni(OH) 2 . U was found to co-deposit as a U(VI) hydroxide. The mode of incorporation of metal ions depends both on the size and charge of the metal ion. The structure of iron oxide (hydroxide) films prepared by both anodic and cathodic deposition has also been extensively studied. The structure of Fe(OH) 2 was determined to be similar to that of α-Ni(OH) 2 . Anodic deposition from solutions containing Fe 2+ results in a film with a structure similar to γ-FeOOH. From the knowledge gained from the present studies, principles and methods for decontamination have become apparent. Contaminants sorbed on oxide surfaces or co-precipitated may be removed by acid wash and selective dissolution or complexation. Ions incorporated into lattice sites and interlamellar layers will require more drastic cleaning procedures. Electropolishing and the use of an electrochemical brush are among concepts that should be considered seriously for the latter

  6. Radioactivity Measurements on Glazed Ceramic Surfaces.

    Science.gov (United States)

    Hobbs, T G

    2000-01-01

    A variety of commonly available household and industrial ceramic items and some specialty glass materials were assayed by alpha pulse counting and ion chamber voltage measurements for radioactivity concentrations. Identification of radionuclides in some of the items was performed by gamma spectroscopy. The samples included tableware, construction tiles and decorative tiles, figurines, and other products with a clay based composition. The concentrations of radioactivity ranged from near background to about four orders of magnitude higher. Almost every nuclide identification test demonstrated some radioactivity content from one or more of the naturally occurring radionuclide series of thorium or uranium. The glazes seemed to contribute most of the activity, although a sample of unglazed pottery greenware showed some activity. Samples of glazing paints and samples of deliberately doped glass from the World War II era were included in the test, as was a section of foam filled poster board. A glass disc with known (232)Th radioactivity concentration was cast for use as a calibration source. The results from the two assay methods are compared, and a projection of sensitivity from larger electret ion chamber devices is presented.

  7. SGP Cloud and Land Surface Interaction Campaign (CLASIC): Measurement Platforms

    Energy Technology Data Exchange (ETDEWEB)

    MA Miller; R Avissar; LK Berg; SA Edgerton; ML Fischer; TJ Jackson; B. Kustas; PJ Lamb; G McFarquhar; Q Min; B Schmid; MS Torn; DD Tuner

    2007-06-01

    The Cloud and Land Surface Interaction Campaign (CLASIC) will be conducted from June 8 to June 30, 2007, at the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site. Data will be collected using eight aircraft equipped with a variety of specialized sensors, four specially instrumented surface sites, and two prototype surface radar systems. The architecture of CLASIC includes a high-altitude surveillance aircraft and enhanced vertical thermodynamic and wind profile measurements that will characterize the synoptic scale structure of the clouds and the land surface within the ACRF SGP site. Mesoscale and microscale structures will be sampled with a variety of aircraft, surface, and radar observations. An overview of the measurement platforms that will be used during the CLASIC are described in this report. The coordination of measurements, especially as it relates to aircraft flight plans, will be discussed in the CLASIC Implementation Plan.

  8. EXPERIMENTAL COMPARISON OF THE AEROSOL METHOD OF DISINFECTION OF AIR AND SURFACES CONTAMINATED BY M. TUBERCULOSIS

    Directory of Open Access Journals (Sweden)

    V. V. Kuzin

    2018-01-01

    instead of disinfectant for control tests treating the tests objects contaminated in the same manner.Results. The good disinfection properties of Green Dez aerosol were proved during the simulation of M. tuberculosis, H37Rv strain, disinfection on the surfaces and in the air.The efficiency analysis of the aerosol method of disinfection proved the reduction of disinfectant consumption by 4-5 times versus wiping and irrigation, due to this the aerosol treatment can be regarded as a safer and more environmentally friendly method.The finely dispersed disinfectant aerosol, produced by MNC, effectively decontaminated the whole space, including the remote and hard-to-reach places. Full automation of disinfection implies no human presence providing high safety of disinfection. 

  9. Decontamination and radioactivity measurement on building surfaces related to dismantling of Japan power demonstration reactor (JPDR)

    International Nuclear Information System (INIS)

    Hatakeyama, Mutsuo; Tachibana, Mitsuo; Yanagihara, Satoshi

    1997-12-01

    In the final stage of dismantling activities for decommissioning a nuclear power plant, building structures have to be demolished to release the site for unrestricted use. Since building structures are generally made from massive reinforced concrete materials, it is not a rational way to treat all concrete materials arising from its demolition as radioactive waste. Segregation of radioactive parts from building structures is therefore indispensable. The rational procedures were studied for demolition of building structures by treating arising waste as non-radioactive materials, based on the concept established by Nuclear Safety Commission, then these were implemented in the following way by the JPDR dismantling demonstration project. Areas of the JPDR facilities are categorized into two groups : possibly contaminated areas, and possibly non-contaminated areas, based on the document of the reactor operation. Radioactivity on the building surfaces was then measured to confirm that the qualitative categorization is reasonable. After that, building surfaces were decontaminated in such a way that the contaminated layers were removed with enough margin to separate radioactive parts from non-radioactive building structures. Thought it might be possible to demolish the building structures by treating arising waste as non-radioactive materials, confirmation survey for radioactivity was conducted to show that there is no artificial radioactive nuclides produced by operation in the facility. This report describes the procedures studied on measurement of radioactivity and decontamination, and the results of its implementation in the JPDR dismantling demonstration project. (author)

  10. Measuring and predicting the transport of actinides and fission product contaminants in unsaturated prairie soil

    Science.gov (United States)

    Sims, D. J.

    Soil samples have been taken in 2001 from the area of a 1951 release from an underground storage tank of 6.7 L of an aqueous solution of irradiated uranium (360 GBq). A simulation of the dispersion of the actinides and fission products was conducted in the laboratory using irradiated natural uranium, non-irradiated natural uranium and metal standards dissolved in acidic aqueous solutions and added to soil columns containing uncontaminated prairie soil. The lab soil columns were allowed 12 to 14 months for contaminant transport. Soil samples were analyzed using gamma-ray spectroscopy, neutron activation analysis (NAA) and liquid scintillation counting (LSC) to determine the elemental concentrations of U, Cs and Sr. Diffusion coefficients from the 50 year soil samples and the lab soil samples were determined. The measured diffusion coefficients from the field samples were 3.0 x 10-4 cm2 s-1 (Cs-137), 1.8 x 10-5 cm2 s-1 (U-238) and 2.6 x 10-3 cm2 s-1 (Sr-90) and the values determined from lab simulation were 5 x 10-6 cm 2 s-1 (Cs-137), 3 x 10-5 cm2 s-1 (U-238) and 1.9 x 10-5 cm 2 s-1 (Sr-90). The differences between the sets of diffusion coefficients can be attributed to differences in retardation effects, weather effects and changes in the soil characteristics when transporting, such as porosity. The analytical work showed that Cs-137 content of soil can be determined effectively using gamma-ray spectroscopy; U-238 content can be measured using NAA; and Sr-90 content can be measured using LSC. For non- and low-radioactive species, it was shown that both flame atomic absorption spectrometry (FAAS) and inductively-coupled plasma-mass spectrometry (ICP-MS) gave comparable results for Sr, Cs and Sm, with the average values ranging from 0.5 to 4.5 ppm of each other. The U-238 content results from NAA and from ICP-MS showed general agreement with an average difference of 81.3 ppm on samples having concentrations up to 988.2 ppm. The difference may have been due to matrix

  11. Chemical disinfection of non-porous inanimate surfaces experimentally contaminated with four human pathogenic viruses.

    Science.gov (United States)

    Sattar, S A; Springthorpe, V S; Karim, Y; Loro, P

    1989-06-01

    The chemical disinfection of virus-contaminated non-porous inanimate surfaces was investigated using coxsackievirus B3, adenovirus type 5, parainfluenza virus type 3 and coronavirus 229E as representatives of important nosocomial viral pathogens. A 10 microliter amount of the test virus, suspended in either faeces or mucin, was placed onto each stainless steel disk (about 1 cm in diameter) and the inoculum allowed to dry for 1 h under ambient conditions. Sixteen disinfectant formulations were selected for this study based on the findings of an earlier investigation with a human rotavirus. After 1 min exposure to 20 microliters of the disinfectant, the virus from the disks was immediately eluted into tryptose phosphate broth and plaque assayed. Using an efficacy criterion of a 3 log10 or greater reduction in virus infectivity titre and irrespective of the virus suspending medium, only the following five disinfectants proved to be effective against all the four viruses tested: (1) 2% glutaraldehyde normally used as an instrument soak, (2) a strongly alkaline mixture of 0.5% sodium o-benzyl-p-chlorophenate and 0.6% sodium lauryl sulphate, generally used as a domestic disinfectant cleaner for hard surfaces, (3) a 0.04% solution of a quaternary ammonium compound containing 7% hydrochloric acid, which is the basis of many toilet bowl cleaners, (4) chloramine T at a minimum free chlorine level of 3000 p.p.m. and (5) sodium hypochlorite at a minimum free chlorine concentration of 5000 p.p.m. Of those chemicals suitable for use as topical antiseptics, 70% ethanol alone or products containing at least 70% ethanol were ineffective only against coxsackievirus B3. These results emphasize the care needed in selecting chemical disinfectants for routine use in infection control.

  12. Cuban-Brazilian comparison of the calibration procedures for surface contamination monitors

    International Nuclear Information System (INIS)

    Salas, Gonzalo W.; Garcia, Jose A.T.; Ramos, Manoel M.O.

    2007-01-01

    The calibration laboratory of the CPHR, Centro de Proteccion e Higiene de las Radiaciones, is the only laboratory that performs calibrations of radiation protection instruments in Cuba. Recently they started a cooperation project with IAEA, code number CUB3002-01 with the task title 'Assuring and Demonstrating the safety of radioactive Waste Management'. Within the frame of this project they have a compromise to implement the calibration service for surface contamination monitors, for which they received instruments and sources. In 2006 the Laboratorio Nacional de Metrologia das Radiacoes Ionizantes (LNMRI) from the Instituto de Radioprotecao e Dosimetria, IRD/CNEN, was invited to perform a mission to CPHR in order to evaluate the level of implementation of the service trough the insertion of the service in the Quality Assurance System of their laboratory, and perform a comparison exercise to test the calibration method implemented. The results were evaluated by the methodology recommended in the ISO/IEC 43-1 standard. These results show that all values from both laboratories are comparable for most radionuclides except for Cl-36. The preliminary investigation about this situation is presented in the paper. (author)

  13. Chemical and toxicologic assessment of organic contaminants in surface water using passive samplers

    Science.gov (United States)

    Alvarez, D.A.; Cranor, W.L.; Perkins, S.D.; Clark, R.C.; Smith, S.B.

    2008-01-01

    Passive sampling methodologies were used to conduct a chemical and toxicologic assessment of organic contaminants in the surface waters of three geographically distinct agricultural watersheds. A selection of current-use agrochemicals and persistent organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides, were targeted using the polar organic chemical integrative sampler (POCIS) and the semipermeable membrane device passive samplers. In addition to the chemical analysis, the Microtox assay for acute toxicity and the yeast estrogen screen (YES) were conducted as potential assessment tools in combination with the passive samplers. During the spring of 2004, the passive samplers were deployed for 29 to 65 d at Leary Weber Ditch, IN; Morgan Creek, MD; and DR2 Drain, WA. Chemical analysis of the sampler extracts identified the agrochemicals predominantly used in those areas, including atrazine, simazine, acetochlor, and metolachlor. Other chemicals identified included deethylatrazine and deisopropylatrazine, trifluralin, fluoranthene, pyrene, cis- and trans-nonachlor, and pentachloroanisole. Screening using Microtox resulted in no acutely toxic samples. POCIS samples screened by the YES assay failed to elicit a positive estrogenic response. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  14. Contamination assessment of heavy metal in surface sediments of the Wuding River, northern China

    International Nuclear Information System (INIS)

    Longjiang, M.; Qiang, F.; Duowen, M.; Ke, H.; Jinghong, Y.

    2011-01-01

    The heavy metal contents and the contamination levels of the surface sediments of the Wuding River, northern China, were investigated. Heavy metal concentration ranged in μg g -1 : 50.15 - 71.91 for Cr, 408.1 - 442.9 for Mn, 20.11 - 43.59 for Ni, 17.51 - 20.1 for Cu, 68.32 - 89.57 for Zn, 0.2 - 0.38 for Cd and 15.08 - 16.14 for Pb in the Wuding River sediments. The enrichment factor (EF) and the geo-accumulation index (Igeo) demonstrated that the sediments of the Wuding River had been polluted by Cd, Cr and Ni, which mainly originated from anthropogenic sources, whereas the sediments had not been polluted by Zn, Pb, Cu and Mn, which were derived from the crust. In addition, the assessment results of EF and Igeo suggested that the sediments of the Wuding River was 'moderately' polluted by Cd and 'unpolluted to moderately' polluted by Cr and Ni. The elevated urban sewage discharges and agriculture fertilizers usage in river basin are the anthropogenic sources of these heavy metals in river. (author)

  15. Strippable core-shell polymer emulsion for decontamination of radioactive surface contamination

    International Nuclear Information System (INIS)

    Hwang, Ho-Sang; Seo, Bum-Kyoung; Lee, Kune-Woo

    2011-01-01

    In this study, the core-shell composite polymer for decontamination from the surface contamination was synthesized by the method of emulsion polymerization and blends of polymers. The strippable polymer emulsion is composed of the poly(styrene-ethyl acrylate) [poly(St-EA)] composite polymer, poly(vinyl alcohol) (PVA) and polyvinylpyrrolidone (PVP). The morphology of the poly(St-EA) composite emulsion particle was core-shell structure, with polystyrene (PS) as the core and poly(ethyl acrylate) (PEA) as the shell. Core-shell polymers of styrene (St)/ethyl acrylate (EA) pair were prepared by sequential emulsion polymerization in the presence of sodium dodecyl sulfate (SDS) as an emulsifier using ammonium persulfate (APS) as an initiator. Related tests and analysis confirmed the success in synthesis of composite polymer. The products are characterized by FT-IR spectroscopy, TGA that were used, respectively, to show the structure, the thermal stability of the prepared polymer. Two-phase particles with a core-shell structure were obtained in experiments where the estimated glass transition temperature and the morphologies of emulsion particles. Decontamination factors of the strippable polymeric emulsion were evaluated with the polymer blend contents. (author)

  16. SCO shipments from Rocky Flats - Experience and current practice [Surface Contaminated Object

    International Nuclear Information System (INIS)

    Bracken, Gary; Morris, Robert L.

    2001-01-01

    Decommissioning activities at Rocky Flats Environmental Technology Site (RFETS) are expected to generate approximately 251,000 cubic meters of low-level radioactive waste. Almost half of this will be characterized and shipped as the Department of Transportation ''Surface Contaminated Object'' (SCO) shipping class. In the 2 years since an SCO characterization method was implemented, almost 11,000 of the 18,000 cubic meters of low-level waste were SCO. RFETS experience to-date using an SCO waste characterization method has shown significant time and cost savings, reduced errors, and enhanced employee safety. SCO waste is characterized prior to packaging, near the point of generation, by any of the site's 300 Radiological Control Technicians using inexpensive radiological control survey instruments. This reduces on-site waste container moves and eliminates radiometric analysis at centrally located drum or crate counters. Containers too large for crate counters can also be characterized. Current instrumentation is not adequate to take full advantage of the SCO regulations. Future improvements in the SCO characterization and shipping process are focused on use of larger and/or reusable containers, extended-range instruments, and additional statistical methods, so that the full extent of the SCO regulations can be used

  17. Dynamical Mass Measurements of Contaminated Galaxy Clusters Using Support Distribution Machines

    Science.gov (United States)

    Ntampaka, Michelle; Trac, Hy; Sutherland, Dougal; Fromenteau, Sebastien; Poczos, Barnabas; Schneider, Jeff

    2018-01-01

    We study dynamical mass measurements of galaxy clusters contaminated by interlopers and show that a modern machine learning (ML) algorithm can predict masses by better than a factor of two compared to a standard scaling relation approach. We create two mock catalogs from Multidark’s publicly available N-body MDPL1 simulation, one with perfect galaxy cluster membership infor- mation and the other where a simple cylindrical cut around the cluster center allows interlopers to contaminate the clusters. In the standard approach, we use a power-law scaling relation to infer cluster mass from galaxy line-of-sight (LOS) velocity dispersion. Assuming perfect membership knowledge, this unrealistic case produces a wide fractional mass error distribution, with a width E=0.87. Interlopers introduce additional scatter, significantly widening the error distribution further (E=2.13). We employ the support distribution machine (SDM) class of algorithms to learn from distributions of data to predict single values. Applied to distributions of galaxy observables such as LOS velocity and projected distance from the cluster center, SDM yields better than a factor-of-two improvement (E=0.67) for the contaminated case. Remarkably, SDM applied to contaminated clusters is better able to recover masses than even the scaling relation approach applied to uncon- taminated clusters. We show that the SDM method more accurately reproduces the cluster mass function, making it a valuable tool for employing cluster observations to evaluate cosmological models.

  18. Measurements of radon progeny activity on typical indoor surfaces

    International Nuclear Information System (INIS)

    Knutson, E.O.; Gogolak, C.V.; Klemic, G.

    1992-01-01

    A number of studies aimed at defining how well radon progeny on surfaces can be measured, information that is needed in order to test physical/mathematical models governing indoor radon progeny behaviour, are described. One experiment compared the decomposition on to different surfaces. Only relatively small differences were found among metal, filter paper, broadcloth, corduroy fabric, vinyl wallpaper, glass, and latex paint, but polyethylene film collected two to four times as much as the others, due most likely to electrostatic charge on the plastic surface. Another experiment compared the gamma and gross alpha count methods of measuring surface activity for metal, filter paper, broadcloth and corduroy surfaces. No difference for the surfaces tested was found from which it is concluded that, even for rougher surfaces, progeny atoms deposit mainly on the outer layers. A final experiment compared in situ and surrogate-surface methods for measuring surface deposition. For most tests, the two methods agreed within 30%, and the average ratio was not significantly different from unity. 210 Po is a complication in the in situ method. An unexpected location effect was found in the experiments conducted in houses with high radon concentrations: the deposition on the ceiling was higher than on the surfaces. (author)

  19. Stochastic Radiative Transfer Model for Contaminated Rough Surfaces: A Framework for Detection System Design

    Science.gov (United States)

    2013-11-01

    example for the detection of a potassium chlorate contaminated “car” with a CO2 tunable laser system. 15. SUBJECT TERMS Radiative transfer...detector m-out-of-n detector Potassium chlorate Probability theory System performance Probability of detection and false alarm iii...for the detection of a potassium chlorate contaminated “car” with a CO2 tunable laser system. Subject Terms Radiative transfer, contaminated

  20. HYDROLASING OF CONTAMINATED UNDERWATER BASIN SURFACES AT THE HANFORD K AREA

    International Nuclear Information System (INIS)

    CHRONISTER, G.B.

    2005-01-01

    This paper discusses selecting and implementing hydrolasing technology to reduce radioactive contamination in preparing to dispose of the K Basins; two highly contaminated concrete basins at the Hanford Site. A large collection of spent nuclear fuel stored for many years underwater at the K Basins has been removed to stable, dry, safe storage. Remediation activities have begun for the remaining highly contaminated water. sludge, and concrete basin structures. Hydrolasing will be used to decontaminate and prepare the basin structures for disposal

  1. Contamination of surface and underground waters owing to the disaster of the Sasa mine tailing pond

    OpenAIRE

    Mircovski, Vojo; Spasovski, Orce

    2003-01-01

    The uncontrolled run off of flotation waste from the Sasa Mine causes contamination of the flows of the Rivers Kamenicka and Bregalnica as well as the water of Kalimanci Lake and further afield. Boundary, fracture and karst type of aquifers formed depending on the structural type of porosity along the marginal parts of the terrain. The aquifers are recharged mostly by the above mentioned rivers that results in contamination of their waters. Contamination of underground waters is particularly ...

  2. Tritium surface loading due to contamination of rainwater from atmospheric release at NAPS (2011)

    International Nuclear Information System (INIS)

    Gautam, Y.P.; Sharma, Saivajay; Rao, K.S.; Singh, Bhikam; Kumar, Avinash; Ravi, P.M.

    2012-01-01

    Annual tritium (HTO) surface loading has been measured and calculated for the year 2011 within 0.8 km distance from 145 m high stack of Narora Atomic Power Station (NAPS) at eight locations in different directions. The technique for measured values consists of the summation of product of tritium concentration (Bq/l) in daily rainfall samples and daily rainfall (mm). Tritium surface loading studies at NAPS reveal that a fraction 1.01E-03 of total annual tritium released through stack gets deposited on the surface due to washout/rainout of plume within 0.8 km radial distance from stack. The range of deposition velocity, Vw (m.s -1 ) i.e., the ratio of annual tritium surface loading W (Bq. m -2 .s -1 ) and annual mean tritium concentration in air, c 0 (Bq.m -3 ) at three locations for the years 2011 is found to be 6.12E-04 to 2.89E-03. The average value for wet deposition velocity V w for NAPS site is estimated as 3.17E-03 m.s -1 . (author)

  3. Do contaminants originating from state-of-the-art treated wastewater impact the ecological quality of surface waters?

    Science.gov (United States)

    Stalter, Daniel; Magdeburg, Axel; Quednow, Kristin; Botzat, Alexandra; Oehlmann, Jörg

    2013-01-01

    Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0-100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this

  4. Do Contaminants Originating from State-of-the-Art Treated Wastewater Impact the Ecological Quality of Surface Waters?

    Science.gov (United States)

    Stalter, Daniel; Magdeburg, Axel; Quednow, Kristin; Botzat, Alexandra; Oehlmann, Jörg

    2013-01-01

    Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0–100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this

  5. Do contaminants originating from state-of-the-art treated wastewater impact the ecological quality of surface waters?

    Directory of Open Access Journals (Sweden)

    Daniel Stalter

    Full Text Available Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0-100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn, 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in

  6. Dose reconstruction in radioactively contaminated areas based on radiation transport calculations and measurements

    International Nuclear Information System (INIS)

    Hiller, Mauritius Michael

    2015-01-01

    The external radiation exposure at the former village of Metlino, Russia, was reconstructed. The Techa river in Metlino was contaminated by water from the Majak plant. The village was evacuated in 1956 and a reservoir lake created. Absorbed doses in bricks were measured and a model of the present-day and the historic Metlino was created for Monte Carlo calculations. By combining both, the air kerma at shoreline could be reconstructed to evaluate the Techa River Dosimetry System.

  7. Direct Measurement of the Surface Energy of Graphene.

    Science.gov (United States)

    van Engers, Christian D; Cousens, Nico E A; Babenko, Vitaliy; Britton, Jude; Zappone, Bruno; Grobert, Nicole; Perkin, Susan

    2017-06-14

    Graphene produced by chemical vapor deposition (CVD) is a promising candidate for implementing graphene in a range of technologies. In most device configurations, one side of the graphene is supported by a solid substrate, wheras the other side is in contact with a medium of interest, such as a liquid or other two-dimensional material within a van der Waals stack. In such devices, graphene interacts on both faces via noncovalent interactions and therefore surface energies are key parameters for device fabrication and operation. In this work, we directly measured adhesive forces and surface energies of CVD-grown graphene in dry nitrogen, water, and sodium cholate using a modified surface force balance. For this, we fabricated large (∼1 cm 2 ) and clean graphene-coated surfaces with smooth topography at both macro- and nanoscales. By bringing two such surfaces into contact and measuring the force required to separate them, we measured the surface energy of single-layer graphene in dry nitrogen to be 115 ± 4 mJ/m 2 , which was similar to that of few-layer graphene (119 ± 3 mJ/m 2 ). In water and sodium cholate, we measured interfacial energies of 83 ± 7 and 29 ± 6 mJ/m 2 , respectively. Our work provides the first direct measurement of graphene surface energy and is expected to have an impact both on the development of graphene-based devices and contribute to the fundamental understanding of surface interactions.

  8. Open questions in surface topography measurement: a roadmap

    International Nuclear Information System (INIS)

    Leach, Richard; Evans, Christopher; He, Liangyu; Davies, Angela; Duparré, Angela; Henning, Andrew; Jones, Christopher W; O’Connor, Daniel

    2015-01-01

    Control of surface topography has always been of vital importance for manufacturing and many other engineering and scientific disciplines. However, despite over one hundred years of quantitative surface topography measurement, there are still many open questions. At the top of the list of questions is ‘Are we getting the right answer?’ This begs the obvious question ‘How would we know?’ There are many other questions relating to applications, the appropriateness of a technique for a given scenario, or the relationship between a particular analysis and the function of the surface. In this first ‘open questions’ article we have gathered together some experts in surface topography measurement and asked them to address timely, unresolved questions about the subject. We hope that their responses will go some way to answer these questions, address areas where further research is required, and look at the future of the subject. The first section ‘Spatial content characterization for precision surfaces’ addresses the need to characterise the spatial content of precision surfaces. Whilst we have been manufacturing optics for centuries, there still isn’t a consensus on how to specify the surface for manufacture. The most common three methods for spatial characterisation are reviewed and compared, and the need for further work on quantifying measurement uncertainties is highlighted. The article is focussed on optical surfaces, but the ideas are more pervasive. Different communities refer to ‘figure, mid-spatial frequencies, and finish’ and ‘form, waviness, and roughness’, but the mathematics are identical. The second section ‘Light scattering methods’ is focussed on light scattering techniques; an important topic with in-line metrology becoming essential in many manufacturing scenarios. The potential of scattering methods has long been recognized; in the ‘smooth surface limit’ functionally significant relationships can be derived from first

  9. Measurement of Dynamic Friction Coefficient on the Irregular Free Surface

    International Nuclear Information System (INIS)

    Yeom, S. H.; Seo, K. S.; Lee, J. H.; Lee, K. H.

    2007-01-01

    A spent fuel storage cask must be estimated for a structural integrity when an earthquake occurs because it freely stands on ground surface without a restriction condition. Usually the integrity estimation for a seismic load is performed by a FEM analysis, the friction coefficient for a standing surface is an important parame