WorldWideScience

Sample records for maximum contaminant limits

  1. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Science.gov (United States)

    2010-07-01

    ... turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Maximum contaminant levels for turbidity. The maximum contaminant levels for turbidity are applicable to... part. The maximum contaminant levels for turbidity in drinking water, measured at a representative...

  2. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for organic contaminants. 141.61 Section 141.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.61 Maximum contaminant...

  3. 40 CFR 141.62 - Maximum contaminant levels for inorganic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for inorganic contaminants. 141.62 Section 141.62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.62 Maximum...

  4. 40 CFR 141.63 - Maximum contaminant levels (MCLs) for microbiological contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels (MCLs) for microbiological contaminants. 141.63 Section 141.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.63 Maximum...

  5. Hydraulic Limits on Maximum Plant Transpiration

    Science.gov (United States)

    Manzoni, S.; Vico, G.; Katul, G. G.; Palmroth, S.; Jackson, R. B.; Porporato, A. M.

    2011-12-01

    Photosynthesis occurs at the expense of water losses through transpiration. As a consequence of this basic carbon-water interaction at the leaf level, plant growth and ecosystem carbon exchanges are tightly coupled to transpiration. In this contribution, the hydraulic constraints that limit transpiration rates under well-watered conditions are examined across plant functional types and climates. The potential water flow through plants is proportional to both xylem hydraulic conductivity (which depends on plant carbon economy) and the difference in water potential between the soil and the atmosphere (the driving force that pulls water from the soil). Differently from previous works, we study how this potential flux changes with the amplitude of the driving force (i.e., we focus on xylem properties and not on stomatal regulation). Xylem hydraulic conductivity decreases as the driving force increases due to cavitation of the tissues. As a result of this negative feedback, more negative leaf (and xylem) water potentials would provide a stronger driving force for water transport, while at the same time limiting xylem hydraulic conductivity due to cavitation. Here, the leaf water potential value that allows an optimum balance between driving force and xylem conductivity is quantified, thus defining the maximum transpiration rate that can be sustained by the soil-to-leaf hydraulic system. To apply the proposed framework at the global scale, a novel database of xylem conductivity and cavitation vulnerability across plant types and biomes is developed. Conductivity and water potential at 50% cavitation are shown to be complementary (in particular between angiosperms and conifers), suggesting a tradeoff between transport efficiency and hydraulic safety. Plants from warmer and drier biomes tend to achieve larger maximum transpiration than plants growing in environments with lower atmospheric water demand. The predicted maximum transpiration and the corresponding leaf water

  6. 40 CFR 141.51 - Maximum contaminant level goals for inorganic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for inorganic contaminants. 141.51 Section 141.51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...

  7. 40 CFR 141.50 - Maximum contaminant level goals for organic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for organic contaminants. 141.50 Section 141.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...

  8. 40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for microbiological contaminants. 141.52 Section 141.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...

  9. 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.

  10. Proposal for derivation of limit values for skin contamination

    International Nuclear Information System (INIS)

    Schieferdecker, H.; Koelzer, W.; Henrichs, K.

    1985-04-01

    From the primary limit value for the skin dose secondary limit values are derived for skin contamination which can be used in practical radiation protection work. In analogy to the secondary limit value for the maximum permissible body burden in case of incorporation, limit values for the 'maximum permissible skin burden' are calculated with the help of dose factors for application in case of skin contamination. They can be derived from the skin dose limit values. Considering that the skin is exposed to contamination but temporarily, in analogy to the annual limit on intake in case of incorporation a 'limit value of skin contamination' is derived for immediately removable contaminations and for one day of exposure, whereas with respect to non-removable contamination and taking into account the renewal of the skin, a limit value of annual skin contamination is defined for non-removable skin contaminations. An investigation level for skin contamination is assumed as a threshold above which defined measures must be taken. Regarding these measures not more than three times appropriate washing is recommended with the subsequent procedure determined by the level of residual contamination. The respective limit values are indicated for some radionuclides selected as examples (C-14, Co-60, Sr-90, Y-90, I-131, Cs-137, Ce-141, Pu-239). (orig./HP) [de

  11. Proposed derivation of skin contamination and skin decontamination limits

    International Nuclear Information System (INIS)

    Schieferdecker, H.; Koelzer, W.; Henrichs, K.

    1986-01-01

    From the primary dose limits for the skin, secondary dose limits were derived for skin contamination which can be used in practical radiation protection work. Analogous to the secondary dose limit for the maximum permissible body burden in the case of incorporation, dose limits for the 'maximum permissible skin burden' were calculated, with the help of dose factors, for application in the case of skin contamination. They can be derived from the skin dose limit values. For conditions in which the skin is exposed to temporary contamination, a limit of skin contamination was derived for immediately removable contamination and for one day of exposure. For non-removable contamination a dose limit of annual skin contamination was defined, taking into account the renewal of the skin. An investigation level for skin contamination was assumed, as a threshold, above which certain measures must be taken; these to include appropriate washing not more than three times, with the subsequent procedure determined by the level of residual contamination. The dose limits are indicated for selected radionuclides. (author)

  12. Maximum penetration level of distributed generation without violating voltage limits

    NARCIS (Netherlands)

    Morren, J.; Haan, de S.W.H.

    2009-01-01

    Connection of Distributed Generation (DG) units to a distribution network will result in a local voltage increase. As there will be a maximum on the allowable voltage increase, this will limit the maximum allowable penetration level of DG. By reactive power compensation (by the DG unit itself) a

  13. Maximum organic carbon limits at different melter feed rates (U)

    International Nuclear Information System (INIS)

    Choi, A.S.

    1995-01-01

    This report documents the results of a study to assess the impact of varying melter feed rates on the maximum total organic carbon (TOC) limits allowable in the DWPF melter feed. Topics discussed include: carbon content; feed rate; feed composition; melter vapor space temperature; combustion and dilution air; off-gas surges; earlier work on maximum TOC; overview of models; and the results of the work completed

  14. Light Obscuration Particle Counter Fuel Contamination Limits

    Science.gov (United States)

    2015-10-08

    two methods for measuring particulate contamination by gravimetric analysis: ASTM D2276 - Standard Test Method for Particulate Contaminant in Aviation...problems with the gravimetric methods is the poor repeatability and reproducibility of the methods , ASTM D2276 has a repeatability of 0.25 mg/L and...collected failing either the particle count or the gravimetric limit, 314 of which failed both methods . 245 false negatives were recorded where the

  15. Maximum time-dependent space-charge limited diode currents

    Energy Technology Data Exchange (ETDEWEB)

    Griswold, M. E. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Fisch, N. J. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

    2016-01-15

    Recent papers claim that a one dimensional (1D) diode with a time-varying voltage drop can transmit current densities that exceed the Child-Langmuir (CL) limit on average, apparently contradicting a previous conjecture that there is a hard limit on the average current density across any 1D diode, as t → ∞, that is equal to the CL limit. However, these claims rest on a different definition of the CL limit, namely, a comparison between the time-averaged diode current and the adiabatic average of the expression for the stationary CL limit. If the current were considered as a function of the maximum applied voltage, rather than the average applied voltage, then the original conjecture would not have been refuted.

  16. Maximum total organic carbon limit for DWPF melter feed

    International Nuclear Information System (INIS)

    Choi, A.S.

    1995-01-01

    DWPF recently decided to control the potential flammability of melter off-gas by limiting the total carbon content in the melter feed and maintaining adequate conditions for combustion in the melter plenum. With this new strategy, all the LFL analyzers and associated interlocks and alarms were removed from both the primary and backup melter off-gas systems. Subsequently, D. Iverson of DWPF- T ampersand E requested that SRTC determine the maximum allowable total organic carbon (TOC) content in the melter feed which can be implemented as part of the Process Requirements for melter feed preparation (PR-S04). The maximum TOC limit thus determined in this study was about 24,000 ppm on an aqueous slurry basis. At the TOC levels below this, the peak concentration of combustible components in the quenched off-gas will not exceed 60 percent of the LFL during off-gas surges of magnitudes up to three times nominal, provided that the melter plenum temperature and the air purge rate to the BUFC are monitored and controlled above 650 degrees C and 220 lb/hr, respectively. Appropriate interlocks should discontinue the feeding when one or both of these conditions are not met. Both the magnitude and duration of an off-gas surge have a major impact on the maximum TOC limit, since they directly affect the melter plenum temperature and combustion. Although the data obtained during recent DWPF melter startup tests showed that the peak magnitude of a surge can be greater than three times nominal, the observed duration was considerably shorter, on the order of several seconds. The long surge duration assumed in this study has a greater impact on the plenum temperature than the peak magnitude, thus making the maximum TOC estimate conservative. Two models were used to make the necessary calculations to determine the TOC limit

  17. Thermoelectric cooler concepts and the limit for maximum cooling

    International Nuclear Information System (INIS)

    Seifert, W; Hinsche, N F; Pluschke, V

    2014-01-01

    The conventional analysis of a Peltier cooler approximates the material properties as independent of temperature using a constant properties model (CPM). Alternative concepts have been published by Bian and Shakouri (2006 Appl. Phys. Lett. 89 212101), Bian (et al 2007 Phys. Rev. B 75 245208) and Snyder et al (2012 Phys. Rev. B 86 045202). While Snyder's Thomson cooler concept results from a consideration of compatibility, the method of Bian et al focuses on the redistribution of heat. Thus, both approaches are based on different principles. In this paper we compare the new concepts to CPM and we reconsider the limit for maximum cooling. The results provide a new perspective on maximum cooling. (paper)

  18. Radiation pressure acceleration: The factors limiting maximum attainable ion energy

    Energy Technology Data Exchange (ETDEWEB)

    Bulanov, S. S.; Esarey, E.; Schroeder, C. B. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Bulanov, S. V. [KPSI, National Institutes for Quantum and Radiological Science and Technology, Kizugawa, Kyoto 619-0215 (Japan); A. M. Prokhorov Institute of General Physics RAS, Moscow 119991 (Russian Federation); Esirkepov, T. Zh.; Kando, M. [KPSI, National Institutes for Quantum and Radiological Science and Technology, Kizugawa, Kyoto 619-0215 (Japan); Pegoraro, F. [Physics Department, University of Pisa and Istituto Nazionale di Ottica, CNR, Pisa 56127 (Italy); Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, University of California, Berkeley, California 94720 (United States)

    2016-05-15

    Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven ion acceleration, with near complete transfer of the laser energy to the ions in the relativistic regime. However, there is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. The tightly focused laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly focused pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the focus, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it transparent for radiation and effectively terminating the acceleration. The off-normal incidence of the laser on the target, due either to the experimental setup, or to the deformation of the target, will also lead to establishing a limit on maximum ion energy.

  19. Global Harmonization of Maximum Residue Limits for Pesticides.

    Science.gov (United States)

    Ambrus, Árpád; Yang, Yong Zhen

    2016-01-13

    International trade plays an important role in national economics. The Codex Alimentarius Commission develops harmonized international food standards, guidelines, and codes of practice to protect the health of consumers and to ensure fair practices in the food trade. The Codex maximum residue limits (MRLs) elaborated by the Codex Committee on Pesticide Residues are based on the recommendations of the FAO/WHO Joint Meeting on Pesticides (JMPR). The basic principles applied currently by the JMPR for the evaluation of experimental data and related information are described together with some of the areas in which further developments are needed.

  20. The tolerance efficiency of Panicum maximum and Helianthus annuus in TNT-contaminated soil and nZVI-contaminated soil.

    Science.gov (United States)

    Jiamjitrpanich, Waraporn; Parkpian, Preeda; Polprasert, Chongrak; Laurent, François; Kosanlavit, Rachain

    2012-01-01

    This study was designed to compare the initial method for phytoremediation involving germination and transplantation. The study was also to determine the tolerance efficiency of Panicum maximum (Purple guinea grass) and Helianthus annuus (Sunflower) in TNT-contaminated soil and nZVI-contaminated soil. It was found that the transplantation of Panicum maximum and Helianthus annuus was more suitable than germination as the initiate method of nano-phytoremediation potting test. The study also showed that Panicum maximum was more tolerance than Helianthus annuus in TNT and nZVI-contaminated soil. Therefore, Panicum maximum in the transplantation method should be selected as a hyperaccumulated plant for nano-phytoremediation potting tests. Maximum tolerance dosage of Panicum maximum to TNT-concentration soil was 320 mg/kg and nZVI-contaminated soil was 1000 mg/kg in the transplantation method.

  1. Noise and physical limits to maximum resolution of PET images

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J.L.; Espana, S. [Dpto. Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain); Vicente, E.; Vaquero, J.J.; Desco, M. [Unidad de Medicina y Cirugia Experimental, Hospital GU ' Gregorio Maranon' , E-28007 Madrid (Spain); Udias, J.M. [Dpto. Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain)], E-mail: jose@nuc2.fis.ucm.es

    2007-10-01

    In this work we show that there is a limit for the maximum resolution achievable with a high resolution PET scanner, as well as for the best signal-to-noise ratio, which are ultimately related to the physical effects involved in the emission and detection of the radiation and thus they cannot be overcome with any particular reconstruction method. These effects prevent the spatial high frequency components of the imaged structures to be recorded by the scanner. Therefore, the information encoded in these high frequencies cannot be recovered by any reconstruction technique. Within this framework, we have determined the maximum resolution achievable for a given acquisition as a function of data statistics and scanner parameters, like the size of the crystals or the inter-crystal scatter. In particular, the noise level in the data as a limitation factor to yield high-resolution images in tomographs with small crystal sizes is outlined. These results have implications regarding how to decide the optimal number of voxels of the reconstructed image or how to design better PET scanners.

  2. Noise and physical limits to maximum resolution of PET images

    International Nuclear Information System (INIS)

    Herraiz, J.L.; Espana, S.; Vicente, E.; Vaquero, J.J.; Desco, M.; Udias, J.M.

    2007-01-01

    In this work we show that there is a limit for the maximum resolution achievable with a high resolution PET scanner, as well as for the best signal-to-noise ratio, which are ultimately related to the physical effects involved in the emission and detection of the radiation and thus they cannot be overcome with any particular reconstruction method. These effects prevent the spatial high frequency components of the imaged structures to be recorded by the scanner. Therefore, the information encoded in these high frequencies cannot be recovered by any reconstruction technique. Within this framework, we have determined the maximum resolution achievable for a given acquisition as a function of data statistics and scanner parameters, like the size of the crystals or the inter-crystal scatter. In particular, the noise level in the data as a limitation factor to yield high-resolution images in tomographs with small crystal sizes is outlined. These results have implications regarding how to decide the optimal number of voxels of the reconstructed image or how to design better PET scanners

  3. Maximum permissible dietary contamination after the accidental release of radioactive materials from a nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Pochin, E E; Rock Carling, Ernest; Court Brown, W M [Medical Research Council, Committee on Protection against Ionizing Radiations, London (United Kingdom); and others

    1960-12-01

    After the accident to No. 1 pile at Windscale on October 10, 1957 (Atomic Energy Office, 1957), the Atomic Energy Authority asked the Medical Research Council for advice on the maximum intake of certain radioactive isotopes that should be regarded as permissible, under emergency conditions, for members of the general population living in, or deriving food from, an area contaminated owing to an accident to a reactor. The Council's Committee on Protection against Ionizing Radiations, together with its Subcommittees on Internal and External Radiations, has considered this problem, and concludes that the intake of radioactive materials by ingestion of contaminated food would generally be the limiting source of hazard after any such accident. Intake by inhalation, or radiation from the exterior, would become of importance only in rather special circumstances. In the following report, therefore, the Committee proposes maximum permissible levels of dietary contamination for the relevant isotopes in the emergency conditions envisaged. In proposing these levels, the Protection Committee has used the fullest information available on the radiation doses that would be delivered to different body tissues and at different ages by the isotopes concerned, and on the ways in which these materials would enter the body.

  4. Maximum permissible dietary contamination after the accidental release of radioactive materials from a nuclear reactor

    International Nuclear Information System (INIS)

    Pochin, E.E.; Rock Carling, Ernest; Court Brown, W.M.

    1960-01-01

    After the accident to No. 1 pile at Windscale on October 10, 1957 (Atomic Energy Office, 1957), the Atomic Energy Authority asked the Medical Research Council for advice on the maximum intake of certain radioactive isotopes that should be regarded as permissible, under emergency conditions, for members of the general population living in, or deriving food from, an area contaminated owing to an accident to a reactor. The Council's Committee on Protection against Ionizing Radiations, together with its Subcommittees on Internal and External Radiations, has considered this problem, and concludes that the intake of radioactive materials by ingestion of contaminated food would generally be the limiting source of hazard after any such accident. Intake by inhalation, or radiation from the exterior, would become of importance only in rather special circumstances. In the following report, therefore, the Committee proposes maximum permissible levels of dietary contamination for the relevant isotopes in the emergency conditions envisaged. In proposing these levels, the Protection Committee has used the fullest information available on the radiation doses that would be delivered to different body tissues and at different ages by the isotopes concerned, and on the ways in which these materials would enter the body

  5. Feedback Limits to Maximum Seed Masses of Black Holes

    International Nuclear Information System (INIS)

    Pacucci, Fabio; Natarajan, Priyamvada; Ferrara, Andrea

    2017-01-01

    The most massive black holes observed in the universe weigh up to ∼10 10 M ⊙ , nearly independent of redshift. Reaching these final masses likely required copious accretion and several major mergers. Employing a dynamical approach that rests on the role played by a new, relevant physical scale—the transition radius—we provide a theoretical calculation of the maximum mass achievable by a black hole seed that forms in an isolated halo, one that scarcely merged. Incorporating effects at the transition radius and their impact on the evolution of accretion in isolated halos, we are able to obtain new limits for permitted growth. We find that large black hole seeds ( M • ≳ 10 4 M ⊙ ) hosted in small isolated halos ( M h ≲ 10 9 M ⊙ ) accreting with relatively small radiative efficiencies ( ϵ ≲ 0.1) grow optimally in these circumstances. Moreover, we show that the standard M • – σ relation observed at z ∼ 0 cannot be established in isolated halos at high- z , but requires the occurrence of mergers. Since the average limiting mass of black holes formed at z ≳ 10 is in the range 10 4–6 M ⊙ , we expect to observe them in local galaxies as intermediate-mass black holes, when hosted in the rare halos that experienced only minor or no merging events. Such ancient black holes, formed in isolation with subsequent scant growth, could survive, almost unchanged, until present.

  6. Feedback Limits to Maximum Seed Masses of Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Pacucci, Fabio; Natarajan, Priyamvada [Department of Physics, Yale University, P.O. Box 208121, New Haven, CT 06520 (United States); Ferrara, Andrea [Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)

    2017-02-01

    The most massive black holes observed in the universe weigh up to ∼10{sup 10} M {sub ⊙}, nearly independent of redshift. Reaching these final masses likely required copious accretion and several major mergers. Employing a dynamical approach that rests on the role played by a new, relevant physical scale—the transition radius—we provide a theoretical calculation of the maximum mass achievable by a black hole seed that forms in an isolated halo, one that scarcely merged. Incorporating effects at the transition radius and their impact on the evolution of accretion in isolated halos, we are able to obtain new limits for permitted growth. We find that large black hole seeds ( M {sub •} ≳ 10{sup 4} M {sub ⊙}) hosted in small isolated halos ( M {sub h} ≲ 10{sup 9} M {sub ⊙}) accreting with relatively small radiative efficiencies ( ϵ ≲ 0.1) grow optimally in these circumstances. Moreover, we show that the standard M {sub •}– σ relation observed at z ∼ 0 cannot be established in isolated halos at high- z , but requires the occurrence of mergers. Since the average limiting mass of black holes formed at z ≳ 10 is in the range 10{sup 4–6} M {sub ⊙}, we expect to observe them in local galaxies as intermediate-mass black holes, when hosted in the rare halos that experienced only minor or no merging events. Such ancient black holes, formed in isolation with subsequent scant growth, could survive, almost unchanged, until present.

  7. Effects of lag and maximum growth in contaminant transport and biodegradation modeling

    International Nuclear Information System (INIS)

    Wood, B.D.; Dawson, C.N.

    1992-06-01

    The effects of time lag and maximum microbial growth on biodegradation in contaminant transport are discussed. A mathematical model is formulated that accounts for these effects, and a numerical case study is presented that demonstrates how lag influences biodegradation

  8. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exposure limits for airborne contaminants. 56... Quality and Physical Agents Air Quality § 56.5001 Exposure limits for airborne contaminants. Except as... contaminants shall not exceed, on the basis of a time weighted average, the threshold limit values adopted by...

  9. Guidance document on the derivation of maximum permissible risk levels for human intake of soil contaminants

    NARCIS (Netherlands)

    Janssen PJCM; Speijers GJA; CSR

    1997-01-01

    This report contains a basic step-to-step description of the procedure followed in the derivation of the human-toxicological Maximum Permissible Risk (MPR ; in Dutch: Maximum Toelaatbaar Risico, MTR) for soil contaminants. In recent years this method has been applied for a large number of compounds

  10. 5 CFR 581.402 - Maximum garnishment limitations.

    Science.gov (United States)

    2010-01-01

    ... PROCESSING GARNISHMENT ORDERS FOR CHILD SUPPORT AND/OR ALIMONY Consumer Credit Protection Act Restrictions..., pursuant to section 1673(b)(2) (A) and (B) of title 15 of the United States Code (the Consumer Credit... local law, the maximum part of the aggregate disposable earnings subject to garnishment to enforce any...

  11. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exposure limits for airborne contaminants. 57... Underground § 57.5001 Exposure limits for airborne contaminants. Except as permitted by § 57.5005— (a) Except as provided in paragraph (b), the exposure to airborne contaminants shall not exceed, on the basis of...

  12. Reduced oxygen at high altitude limits maximum size.

    Science.gov (United States)

    Peck, L S; Chapelle, G

    2003-11-07

    The trend towards large size in marine animals with latitude, and the existence of giant marine species in polar regions have long been recognized, but remained enigmatic until a recent study showed it to be an effect of increased oxygen availability in sea water of a low temperature. The effect was apparent in data from 12 sites worldwide because of variations in water oxygen content controlled by differences in temperature and salinity. Another major physical factor affecting oxygen content in aquatic environments is reduced pressure at high altitude. Suitable data from high-altitude sites are very scarce. However, an exceptionally rich crustacean collection, which remains largely undescribed, was obtained by the British 1937 expedition from Lake Titicaca on the border between Peru and Bolivia in the Andes at an altitude of 3809 m. We show that in Lake Titicaca the maximum length of amphipods is 2-4 times smaller than other low-salinity sites (Caspian Sea and Lake Baikal).

  13. Vehicle Maximum Weight Limitation Based on Intelligent Weight Sensor

    Science.gov (United States)

    Raihan, W.; Tessar, R. M.; Ernest, C. O. S.; E Byan, W. R.; Winda, A.

    2017-03-01

    Vehicle weight is an important factor to be maintained for transportation safety. A weight limitation system is proposed to make sure the vehicle weight is always below its designation prior the vehicle is being used by the driver. The proposed system is divided into two systems, namely vehicle weight confirmation system and weight warning system. In vehicle weight confirmation system, the weight sensor work for the first time after the ignition switch is turned on. When the weight is under the weight limit, the starter engine can be switched on to start the engine system, otherwise it will be locked. The seconds system, will operated after checking all the door at close position, once the door of the car is closed, the weight warning system will check once again the weight during runing engine condition. The results of these two systems, vehicle weight confirmation system and weight warning system have 100 % accuracy, respectively. These show that the proposed vehicle weight limitation system operate well.

  14. Maximum entropy estimation of a Benzene contaminated plume using ecotoxicological assays

    International Nuclear Information System (INIS)

    Wahyudi, Agung; Bartzke, Mariana; Küster, Eberhard; Bogaert, Patrick

    2013-01-01

    Ecotoxicological bioassays, e.g. based on Danio rerio teratogenicity (DarT) or the acute luminescence inhibition with Vibrio fischeri, could potentially lead to significant benefits for detecting on site contaminations on qualitative or semi-quantitative bases. The aim was to use the observed effects of two ecotoxicological assays for estimating the extent of a Benzene groundwater contamination plume. We used a Maximum Entropy (MaxEnt) method to rebuild a bivariate probability table that links the observed toxicity from the bioassays with Benzene concentrations. Compared with direct mapping of the contamination plume as obtained from groundwater samples, the MaxEnt concentration map exhibits on average slightly higher concentrations though the global pattern is close to it. This suggest MaxEnt is a valuable method to build a relationship between quantitative data, e.g. contaminant concentrations, and more qualitative or indirect measurements, in a spatial mapping framework, which is especially useful when clear quantitative relation is not at hand. - Highlights: ► Ecotoxicological shows significant benefits for detecting on site contaminations. ► MaxEnt to rebuild qualitative link on concentration and ecotoxicological assays. ► MaxEnt shows similar pattern when compared with concentrations map of groundwater. ► MaxEnt is a valuable method especially when quantitative relation is not at hand. - A Maximum Entropy method to rebuild qualitative relationships between Benzene groundwater concentrations and their ecotoxicological effect.

  15. Further European initiatives and regulations concerning radiation protection: drinking water guideline, maximum permissible contamination in food products and feeding stuff

    International Nuclear Information System (INIS)

    Mundigl, Stefan

    2013-01-01

    The radiation protection community has observed intensively the development of basic safety standards concerning protection against hazards of ionizing radiation. The new core part of the European radiation protection legislation is complemented by several specialized regulations relevant for radiation protection. Besides the existing regulations in the field of emergency protection the European Commission initiated a drinking water guideline that will be published in the near future. Furthermore the European commission approved a revised regulation concerning the maximum permissible contamination limits for food products and feeding stuff in case of a future nuclear accident. Together with the new radiation protection basic standards a new complete, coherent and modernized European regulation package will be accomplished.

  16. Determining Maximum Photovoltaic Penetration in a Distribution Grid considering Grid Operation Limits

    DEFF Research Database (Denmark)

    Kordheili, Reza Ahmadi; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

    2014-01-01

    High penetration of photovoltaic panels in distribution grid can bring the grid to its operation limits. The main focus of the paper is to determine maximum photovoltaic penetration level in the grid. Three main criteria were investigated for determining maximum penetration level of PV panels...... for this grid: even distribution of PV panels, aggregation of panels at the beginning of each feeder, and aggregation of panels at the end of each feeder. Load modeling is done using Velander formula. Since PV generation is highest in the summer due to irradiation, a summer day was chosen to determine maximum......; maximum voltage deviation of customers, cables current limits, and transformer nominal value. Voltage deviation of different buses was investigated for different penetration levels. The proposed model was simulated on a Danish distribution grid. Three different PV location scenarios were investigated...

  17. Maximum principle and convergence of central schemes based on slope limiters

    KAUST Repository

    Mehmetoglu, Orhan; Popov, Bojan

    2012-01-01

    A maximum principle and convergence of second order central schemes is proven for scalar conservation laws in dimension one. It is well known that to establish a maximum principle a nonlinear piecewise linear reconstruction is needed and a typical choice is the minmod limiter. Unfortunately, this implies that the scheme uses a first order reconstruction at local extrema. The novelty here is that we allow local nonlinear reconstructions which do not reduce to first order at local extrema and still prove maximum principle and convergence. © 2011 American Mathematical Society.

  18. Maximum β limited by ideal MHD ballooning instabilites in JT-60

    International Nuclear Information System (INIS)

    Seki, Shogo; Azumi, Masashi

    1986-03-01

    Maximum β limited by ideal MHD ballooning instabilities is investigated on divertor configurations in JT-60. Maximum β against ballooning modes in JT-60 has strong dependecy on the distribution of the safety factor over the magnetic surfaces. Maximum β is ∼ 2 % for q 0 = 1.0, while more than 3 % for q 0 = 1.5. These results suggest that the profile control of the safety factor, especially on the magnetic axis, is attractive to the higher β operation in JT-60. (author)

  19. Theoretical and experimental investigations of the limits to the maximum output power of laser diodes

    International Nuclear Information System (INIS)

    Wenzel, H; Crump, P; Pietrzak, A; Wang, X; Erbert, G; Traenkle, G

    2010-01-01

    The factors that limit both the continuous wave (CW) and the pulsed output power of broad-area laser diodes driven at very high currents are investigated theoretically and experimentally. The decrease in the gain due to self-heating under CW operation and spectral holeburning under pulsed operation, as well as heterobarrier carrier leakage and longitudinal spatial holeburning, are the dominant mechanisms limiting the maximum achievable output power.

  20. Longitudinal and transverse space charge limitations on transport of maximum power beams

    International Nuclear Information System (INIS)

    Khoe, T.K.; Martin, R.L.

    1977-01-01

    The maximum transportable beam power is a critical issue in selecting the most favorable approach to generating ignition pulses for inertial fusion with high energy accelerators. Maschke and Courant have put forward expressions for the limits on transport power for quadrupole and solenoidal channels. Included in a more general way is the self consistent effect of space charge defocusing on the power limit. The results show that no limits on transmitted power exist in principal. In general, quadrupole transport magnets appear superior to solenoids except for transport of very low energy and highly charged particles. Longitudinal space charge effects are very significant for transport of intense beams

  1. Improved Reliability of Single-Phase PV Inverters by Limiting the Maximum Feed-in Power

    DEFF Research Database (Denmark)

    Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

    2014-01-01

    Grid operation experiences have revealed the necessity to limit the maximum feed-in power from PV inverter systems under a high penetration scenario in order to avoid voltage and frequency instability issues. A Constant Power Generation (CPG) control method has been proposed at the inverter level...... devices, allowing a quantitative prediction of the power device lifetime. A study case on a 3 kW single-phase PV inverter has demonstrated the advantages of the CPG control in terms of improved reliability.......Grid operation experiences have revealed the necessity to limit the maximum feed-in power from PV inverter systems under a high penetration scenario in order to avoid voltage and frequency instability issues. A Constant Power Generation (CPG) control method has been proposed at the inverter level....... The CPG control strategy is activated only when the DC input power from PV panels exceeds a specific power limit. It enables to limit the maximum feed-in power to the electric grids and also to improve the utilization of PV inverters. As a further study, this paper investigates the reliability performance...

  2. Impact of sensor detection limits on protecting water distribution systems from contamination events

    International Nuclear Information System (INIS)

    McKenna, Sean Andrew; Hart, David Blaine; Yarrington, Lane

    2006-01-01

    Real-time water quality sensors are becoming commonplace in water distribution systems. However, field deployable, contaminant-specific sensors are still in the development stage. As development proceeds, the necessary operating parameters of these sensors must be determined to protect consumers from accidental and malevolent contamination events. This objective can be quantified in several different ways including minimization of: the time necessary to detect a contamination event, the population exposed to contaminated water, the extent of the contamination within the network, and others. We examine the ability of a sensor set to meet these objectives as a function of both the detection limit of the sensors and the number of sensors in the network. A moderately sized distribution network is used as an example and different sized sets of randomly placed sensors are considered. For each combination of a certain number of sensors and a detection limit, the mean values of the different objectives across multiple random sensor placements are calculated. The tradeoff between the necessary detection limit in a sensor and the number of sensors is evaluated. Results show that for the example problem examined here, a sensor detection limit of 0.01 of the average source concentration is adequate for maximum protection. Detection of events is dependent on the detection limit of the sensors, but for those events that are detected, the values of the performance measures are not a function of the sensor detection limit. The results of replacing a single sensor in a network with a sensor having a much lower detection limit show that while this replacement can improve results, the majority of the additional events detected had performance measures of relatively low consequence.

  3. Maximum total organic carbon limits at different DWPF melter feed maters (U)

    International Nuclear Information System (INIS)

    Choi, A.S.

    1996-01-01

    The document presents information on the maximum total organic carbon (TOC) limits that are allowable in the DWPF melter feed without forming a potentially flammable vapor in the off-gas system were determined at feed rates varying from 0.7 to 1.5 GPM. At the maximum TOC levels predicted, the peak concentration of combustible gases in the quenched off-gas will not exceed 60 percent of the lower flammable limit during a 3X off-gas surge, provided that the indicated melter vapor space temperature and the total air supply to the melter are maintained. All the necessary calculations for this study were made using the 4-stage cold cap model and the melter off-gas dynamics model. A high-degree of conservatism was included in the calculational bases and assumptions. As a result, the proposed correlations are believed to by conservative enough to be used for the melter off-gas flammability control purposes

  4. Maximum Throughput in a C-RAN Cluster with Limited Fronthaul Capacity

    OpenAIRE

    Duan , Jialong; Lagrange , Xavier; Guilloud , Frédéric

    2016-01-01

    International audience; Centralized/Cloud Radio Access Network (C-RAN) is a promising future mobile network architecture which can ease the cooperation between different cells to manage interference. However, the feasibility of C-RAN is limited by the large bit rate requirement in the fronthaul. This paper study the maximum throughput of different transmission strategies in a C-RAN cluster with transmission power constraints and fronthaul capacity constraints. Both transmission strategies wit...

  5. Avinash-Shukla mass limit for the maximum dust mass supported against gravity by electric fields

    Science.gov (United States)

    Avinash, K.

    2010-08-01

    The existence of a new class of astrophysical objects, where gravity is balanced by the shielded electric fields associated with the electric charge on the dust, is shown. Further, a mass limit MA for the maximum dust mass that can be supported against gravitational collapse by these fields is obtained. If the total mass of the dust in the interstellar cloud MD > MA, the dust collapses, while if MD < MA, stable equilibrium may be achieved. Heuristic arguments are given to show that the physics of the mass limit is similar to the Chandrasekar's mass limit for compact objects and the similarity of these dust configurations with neutron and white dwarfs is pointed out. The effect of grain size distribution on the mass limit and strong correlation effects in the core of such objects is discussed. Possible location of these dust configurations inside interstellar clouds is pointed out.

  6. Limitations of sorption isotherms on modeling groundwater contaminant transport

    International Nuclear Information System (INIS)

    Silva, Eduardo Figueira da

    2007-01-01

    Design and safety assessment of radioactive waste repositories, as well as remediation of radionuclide contaminated groundwater require the development of models capable of accurately predicting trace element fate and transport. Adsorption of trace radionuclides onto soils and groundwater is an important mechanism controlling near- and far- field transport. Although surface complexation models (SCMs) can better describe the adsorption mechanisms of most radionuclides onto mineral surfaces by directly accounting for variability of system properties and mineral surface properties, isotherms are still used to model contaminant transport in groundwater, despite the much higher system dependence. The present work investigates differences between transport model results based on these two approaches for adsorption modeling. A finite element transport model is used for the isotherm model, whereas the computer program PHREEQC is used for the SCM approach. Both models are calibrated for a batch experiment, and one-dimensional transport is simulated using the calibrated parameters. At the lower injected concentrations there are large discrepancies between SCM and isotherm transport predictions, with the SCM presenting much longer tails on the breakthrough curves. Isotherms may also provide non-conservative results for time to breakthrough and for maximum concentration in a contamination plume. Isotherm models are shown not to be robust enough to predict transport behavior of some trace elements, thus discouraging their use. The results also illustrate the promise of the SCM modeling approach in safety assessment and environmental remediation applications, also suggesting that independent batch sorption measurements can be used, within the framework of the SCM, to produce a more versatile and realistic groundwater transport model for radionuclides which is capable of accounting more accurately for temporal and spatial variations in geochemical conditions. (author)

  7. Mechanical limits to maximum weapon size in a giant rhinoceros beetle.

    Science.gov (United States)

    McCullough, Erin L

    2014-07-07

    The horns of giant rhinoceros beetles are a classic example of the elaborate morphologies that can result from sexual selection. Theory predicts that sexual traits will evolve to be increasingly exaggerated until survival costs balance the reproductive benefits of further trait elaboration. In Trypoxylus dichotomus, long horns confer a competitive advantage to males, yet previous studies have found that they do not incur survival costs. It is therefore unlikely that horn size is limited by the theoretical cost-benefit equilibrium. However, males sometimes fight vigorously enough to break their horns, so mechanical limits may set an upper bound on horn size. Here, I tested this mechanical limit hypothesis by measuring safety factors across the full range of horn sizes. Safety factors were calculated as the ratio between the force required to break a horn and the maximum force exerted on a horn during a typical fight. I found that safety factors decrease with increasing horn length, indicating that the risk of breakage is indeed highest for the longest horns. Structural failure of oversized horns may therefore oppose the continued exaggeration of horn length driven by male-male competition and set a mechanical limit on the maximum size of rhinoceros beetle horns. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  8. Defining the Glass Composition Limits for SRS Contaminated Soils

    International Nuclear Information System (INIS)

    Cicero, C.A.; Bickford, D.F.; Crews, W.O.

    1995-01-01

    Contaminated soil resulting from the excavation, repair, and decommissioning of facilities located at the Savannah River Site (SRS) is currently being disposed of by shallow land burial or is being stored when considered only hazardous. Vitrification of this waste is being investigated, since it will bind the hazardous and radioactive species in a stable and durable glass matrix, which will reduce the risk of ground water contamination. However, the composition limits for producing durable glass have to be determined before the technology can be applied. Glass compositions, consisting of SRS soil and glass forming additives, were tested on a crucible-scale in three ternary phase systems. Nine different glass compositions were produced, with waste loadings ranging from 43 to 58 weight percent. These were characterized using varoius chemical methods and tested for durability in both alkaline and acidic environments. All nine performed well in alkaline environments, but only three met the strictest criteria for the acidic environment tests. Although the glasses did not meet all of the limits for the acidic tests, the test was performed on very conservative size samples, so the results were also conservative. Therefore, enough evidence was found to provide proof that SRS soil can be vitrified in a durable glass matrix

  9. Waste material recycling: Assessment of contaminants limiting recycling

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn

    systematically investigated. This PhD project provided detailed quantitative data following a consistent approach to assess potential limitations for the presence of chemicals in relation to material recycling. Paper and plastics were used as illustrative examples of materials with well-established recycling...... schemes and great potential for increase in recycling, respectively. The approach followed in the present work was developed and performed in four distinct steps. As step one, fractional composition of waste paper (30 fractions) and plastics (9 fractions) from households in Åbenrå municipality (Southern...... detrimental to their recycling. Finally, a material flow analysis (MFA) approach revealed the potential for accumulation and spreading of contaminants in material recycling, on the example of the European paper cycle. Assessment of potential mitigation measures indicated that prevention of chemical use...

  10. Evaluation of regulatory variation and theoretical health risk for pesticide maximum residue limits in food.

    Science.gov (United States)

    Li, Zijian

    2018-08-01

    To evaluate whether pesticide maximum residue limits (MRLs) can protect public health, a deterministic dietary risk assessment of maximum pesticide legal exposure was conducted to convert global MRLs to theoretical maximum dose intake (TMDI) values by estimating the average food intake rate and human body weight for each country. A total of 114 nations (58% of the total nations in the world) and two international organizations, including the European Union (EU) and Codex (WHO) have regulated at least one of the most currently used pesticides in at least one of the most consumed agricultural commodities. In this study, 14 of the most commonly used pesticides and 12 of the most commonly consumed agricultural commodities were identified and selected for analysis. A health risk analysis indicated that nearly 30% of the computed pesticide TMDI values were greater than the acceptable daily intake (ADI) values; however, many nations lack common pesticide MRLs in many commonly consumed foods and other human exposure pathways, such as soil, water, and air were not considered. Normality tests of the TMDI values set indicated that all distributions had a right skewness due to large TMDI clusters at the low end of the distribution, which were caused by some strict pesticide MRLs regulated by the EU (normally a default MRL of 0.01 mg/kg when essential data are missing). The Box-Cox transformation and optimal lambda (λ) were applied to these TMDI distributions, and normality tests of the transformed data set indicated that the power transformed TMDI values of at least eight pesticides presented a normal distribution. It was concluded that unifying strict pesticide MRLs by nations worldwide could significantly skew the distribution of TMDI values to the right, lower the legal exposure to pesticide, and effectively control human health risks. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Physical Limits on Hmax, the Maximum Height of Glaciers and Ice Sheets

    Science.gov (United States)

    Lipovsky, B. P.

    2017-12-01

    The longest glaciers and ice sheets on Earth never achieve a topographic relief, or height, greater than about Hmax = 4 km. What laws govern this apparent maximum height to which a glacier or ice sheet may rise? Two types of answer appear possible: one relating to geological process and the other to ice dynamics. In the first type of answer, one might suppose that if Earth had 100 km tall mountains then there would be many 20 km tall glaciers. The counterpoint to this argument is that recent evidence suggests that glaciers themselves limit the maximum height of mountain ranges. We turn, then, to ice dynamical explanations for Hmax. The classical ice dynamical theory of Nye (1951), however, does not predict any break in scaling to give rise to a maximum height, Hmax. I present a simple model for the height of glaciers and ice sheets. The expression is derived from a simplified representation of a thermomechanically coupled ice sheet that experiences a basal shear stress governed by Coulomb friction (i.e., a stress proportional to the overburden pressure minus the water pressure). I compare this model to satellite-derived digital elevation map measurements of glacier surface height profiles for the 200,000 glaciers in the Randolph Glacier Inventory (Pfeffer et al., 2014) as well as flowlines from the Greenland and Antarctic Ice Sheets. The simplified model provides a surprisingly good fit to these global observations. Small glaciers less than 1 km in length are characterized by having negligible influence of basal melt water, cold ( -15C) beds, and high surface slopes ( 30 deg). Glaciers longer than a critical distance 30km are characterized by having an ice-bed interface that is weakened by the presence of meltwater and is therefore not capable of supporting steep surface slopes. The simplified model makes predictions of ice volume change as a function of surface temperature, accumulation rate, and geothermal heat flux. For this reason, it provides insights into

  12. Maximum Permissible Risk Levels for Human Intake of Soil Contaminants: Fourth Series of Compounds

    NARCIS (Netherlands)

    Janssen PJCM; Apeldoorn ME van; Engelen JGM van; Schielen PCJI; Wouters MFA; CSR

    1998-01-01

    This report documents the human-toxicological risk assessment work done in 1996 and 1997 at RIVM's Centre for Substances and Risk Assessment within the scope of the RIVM project on soil intervention values for soil clean-up. The method used for derivation of the Maximum Permissible Risk, as

  13. Do swimming goggles limit microbial contamination of contact lenses?

    Science.gov (United States)

    Wu, Yvonne T; Tran, Jess; Truong, Michelle; Harmis, Najat; Zhu, Hua; Stapleton, Fiona

    2011-04-01

    Wearing goggles over contact lenses while swimming is often recommended by eye care professionals. Limited data are available to assess this recommendation. The purpose of this study was to examine whether wearing goggles while swimming limits bacterial colonization on contact lenses and whether the type of lens worn affects contamination rates. Twenty-three subjects underwent two swimming sessions at an ocean (salt water) pool (Maroubra beach Rock Pool, Sydney, Australia). Silicone hydrogel (Ciba Focus Night and Day) or hydrogel lenses (Ciba Focus Daily) were inserted into subjects' eyes before 30 min of swimming sessions, and subjects used modified goggles to mimic goggled and non-goggled conditions. At the end of each session, lenses were collected for microbial investigation. Viable bacterial colonies were classified as gram positive and gram negative and enumerated. The level of bacterial colonization on contact lenses between goggled and non-goggled conditions and between the two lens materials were compared. The range of colony forming units recovered from goggled lenses were 0 to 930 compared with 0 to 1210 on non-goggled lenses. The majority of subjects (16/23) had more microorganisms in the non-goggled condition than when wearing goggles (p = 0.03). Gram negative organisms were found in three non-goggled lenses. No significant difference was shown in the number of bacteria isolated from silicone hydrogel and hydrogel lenses (p > 0.6) irrespective of wearing goggles. Water samples had consistently higher numbers of bacterial counts than those adhered to the lenses; however, no association was found between the number of bacteria in the water sample and those found on the contact lenses. Consistently, fewer bacterial colonies were found on the goggled contact lens, thus suggesting goggles offer some protection against bacterial colonization of contact lenses while swimming. These data would support the recommendation encouraging lens wearers to use goggles

  14. The Maximum Entropy Limit of Small-scale Magnetic Field Fluctuations in the Quiet Sun

    Science.gov (United States)

    Gorobets, A. Y.; Berdyugina, S. V.; Riethmüller, T. L.; Blanco Rodríguez, J.; Solanki, S. K.; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; van Noort, M.; Del Toro Iniesta, J. C.; Orozco Suárez, D.; Schmidt, W.; Martínez Pillet, V.; Knölker, M.

    2017-11-01

    The observed magnetic field on the solar surface is characterized by a very complex spatial and temporal behavior. Although feature-tracking algorithms have allowed us to deepen our understanding of this behavior, subjectivity plays an important role in the identification and tracking of such features. In this paper, we continue studies of the temporal stochasticity of the magnetic field on the solar surface without relying either on the concept of magnetic features or on subjective assumptions about their identification and interaction. We propose a data analysis method to quantify fluctuations of the line-of-sight magnetic field by means of reducing the temporal field’s evolution to the regular Markov process. We build a representative model of fluctuations converging to the unique stationary (equilibrium) distribution in the long time limit with maximum entropy. We obtained different rates of convergence to the equilibrium at fixed noise cutoff for two sets of data. This indicates a strong influence of the data spatial resolution and mixing-polarity fluctuations on the relaxation process. The analysis is applied to observations of magnetic fields of the relatively quiet areas around an active region carried out during the second flight of the Sunrise/IMaX and quiet Sun areas at the disk center from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory satellite.

  15. The Betz-Joukowsky limit for the maximum power coefficient of wind turbines

    DEFF Research Database (Denmark)

    Okulov, Valery; van Kuik, G.A.M.

    2009-01-01

    The article addresses to a history of an important scientific result in wind energy. The maximum efficiency of an ideal wind turbine rotor is well known as the ‘Betz limit’, named after the German scientist that formulated this maximum in 1920. Also Lanchester, a British scientist, is associated...

  16. Detection of maximum loadability limits and weak buses using Chaotic PSO considering security constraints

    International Nuclear Information System (INIS)

    Acharjee, P.; Mallick, S.; Thakur, S.S.; Ghoshal, S.P.

    2011-01-01

    Highlights: → The unique cost function is derived considering practical Security Constraints. → New innovative formulae of PSO parameters are developed for better performance. → The inclusion and implementation of chaos in PSO technique is original and unique. → Weak buses are identified where FACTS devices can be implemented. → The CPSO technique gives the best performance for all the IEEE standard test systems. - Abstract: In the current research chaotic search is used with the optimization technique for solving non-linear complicated power system problems because Chaos can overcome the local optima problem of optimization technique. Power system problem, more specifically voltage stability, is one of the practical examples of non-linear, complex, convex problems. Smart grid, restructured energy system and socio-economic development fetch various uncertain events in power systems and the level of uncertainty increases to a great extent day by day. In this context, analysis of voltage stability is essential. The efficient method to assess the voltage stability is maximum loadability limit (MLL). MLL problem is formulated as a maximization problem considering practical security constraints (SCs). Detection of weak buses is also important for the analysis of power system stability. Both MLL and weak buses are identified by PSO methods and FACTS devices can be applied to the detected weak buses for the improvement of stability. Three particle swarm optimization (PSO) techniques namely General PSO (GPSO), Adaptive PSO (APSO) and Chaotic PSO (CPSO) are presented for the comparative study with obtaining MLL and weak buses under different SCs. In APSO method, PSO-parameters are made adaptive with the problem and chaos is incorporated in CPSO method to obtain reliable convergence and better performances. All three methods are applied on standard IEEE 14 bus, 30 bus, 57 bus and 118 bus test systems to show their comparative computing effectiveness and

  17. Bayesian Reliability Estimation for Deteriorating Systems with Limited Samples Using the Maximum Entropy Approach

    OpenAIRE

    Xiao, Ning-Cong; Li, Yan-Feng; Wang, Zhonglai; Peng, Weiwen; Huang, Hong-Zhong

    2013-01-01

    In this paper the combinations of maximum entropy method and Bayesian inference for reliability assessment of deteriorating system is proposed. Due to various uncertainties, less data and incomplete information, system parameters usually cannot be determined precisely. These uncertainty parameters can be modeled by fuzzy sets theory and the Bayesian inference which have been proved to be useful for deteriorating systems under small sample sizes. The maximum entropy approach can be used to cal...

  18. Bayesian Reliability Estimation for Deteriorating Systems with Limited Samples Using the Maximum Entropy Approach

    Directory of Open Access Journals (Sweden)

    Ning-Cong Xiao

    2013-12-01

    Full Text Available In this paper the combinations of maximum entropy method and Bayesian inference for reliability assessment of deteriorating system is proposed. Due to various uncertainties, less data and incomplete information, system parameters usually cannot be determined precisely. These uncertainty parameters can be modeled by fuzzy sets theory and the Bayesian inference which have been proved to be useful for deteriorating systems under small sample sizes. The maximum entropy approach can be used to calculate the maximum entropy density function of uncertainty parameters more accurately for it does not need any additional information and assumptions. Finally, two optimization models are presented which can be used to determine the lower and upper bounds of systems probability of failure under vague environment conditions. Two numerical examples are investigated to demonstrate the proposed method.

  19. Contamination limits for real and personal property. Progress report, January--June 1976

    International Nuclear Information System (INIS)

    Healy, J.W.; Wenzel, W.J.

    1976-09-01

    Progress is reported on the plutonium in soils limit and on the surface contamination study. The report on the soils limit is being typed in draft form for review at other ERDA facilities. A model for surface contamination was derived and programmed but parametric studies have not yet been done

  20. Overcoming phytoremediation limitations. A case study of Hg contaminated soil

    Science.gov (United States)

    Barbafieri, Meri

    2013-04-01

    Phytoremediation is a broad term that comprises several technologies to clean up water and soil. Despite the numerous articles appearing in scientific journals, very few field applications of phytoextraction have been successfully realized. The research here reported on Phytoextraction, the use the plant to "extract" metals from contaminated soil, is focused on implementations to overcome two main drawbacks: the survival of plants in unfavorable environmental conditions (contaminant toxicity, low fertility, etc.) and the often lengthy time it takes to reduce contaminants to the requested level. Moreover, to overcome the imbalance between the technology's potential and its drawbacks, there is growing interest in the use of plants to reduce only the fraction that is the most hazardous to the environment and human health, that is to target the bioavailable fractions of metals in soil. Bioavailable Contaminant Stripping (BCS) would be a remediation approach focused to remove the bioavailable metal fractions. BCS have been used in a mercury contaminated soil from Italian industrial site. Bioavailable fractions were determined by sequential extraction with H2O and NH4Cl.Combined treatments of plant hormone and thioligand to strength Hg uptake by crop plants (Brassica juncea and Helianthus annuus) were tested. Plant biomass, evapotranspiration, Hg uptake and distribution following treatments were compared. Results indicate the plant hormone, cytokinine (CK) foliar treatment, increased evapotranspiration rate in both tested plants. The Hg uptake and translocation in both tested plants increased with simultaneous addition of CK and TS treatments. B. juncea was the most effective in Hg uptake. Application of CK to plants grown in TS-treated soil lead to an increase in Hg concentration of 232% in shoots and 39% in roots with respect to control. While H. annuus gave a better response in plant biomass production, the application of CK to plants grown in TS-treated soil lead to

  1. The impact of regulations, safety considerations and physical limitations on research progress at maximum biocontainment.

    Science.gov (United States)

    Shurtleff, Amy C; Garza, Nicole; Lackemeyer, Matthew; Carrion, Ricardo; Griffiths, Anthony; Patterson, Jean; Edwin, Samuel S; Bavari, Sina

    2012-12-01

    We describe herein, limitations on research at biosafety level 4 (BSL-4) containment laboratories, with regard to biosecurity regulations, safety considerations, research space limitations, and physical constraints in executing experimental procedures. These limitations can severely impact the number of collaborations and size of research projects investigating microbial pathogens of biodefense concern. Acquisition, use, storage, and transfer of biological select agents and toxins (BSAT) are highly regulated due to their potential to pose a severe threat to public health and safety. All federal, state, city, and local regulations must be followed to obtain and maintain registration for the institution to conduct research involving BSAT. These include initial screening and continuous monitoring of personnel, controlled access to containment laboratories, accurate and current BSAT inventory records. Safety considerations are paramount in BSL-4 containment laboratories while considering the types of research tools, workflow and time required for conducting both in vivo and in vitro experiments in limited space. Required use of a positive-pressure encapsulating suit imposes tremendous physical limitations on the researcher. Successful mitigation of these constraints requires additional time, effort, good communication, and creative solutions. Test and evaluation of novel vaccines and therapeutics conducted under good laboratory practice (GLP) conditions for FDA approval are prioritized and frequently share the same physical space with important ongoing basic research studies. The possibilities and limitations of biomedical research involving microbial pathogens of biodefense concern in BSL-4 containment laboratories are explored in this review.

  2. The Impact of Regulations, Safety Considerations and Physical Limitations on Research Progress at Maximum Biocontainment

    Directory of Open Access Journals (Sweden)

    Jean Patterson

    2012-12-01

    Full Text Available We describe herein, limitations on research at biosafety level 4 (BSL-4 containment laboratories, with regard to biosecurity regulations, safety considerations, research space limitations, and physical constraints in executing experimental procedures. These limitations can severely impact the number of collaborations and size of research projects investigating microbial pathogens of biodefense concern. Acquisition, use, storage, and transfer of biological select agents and toxins (BSAT are highly regulated due to their potential to pose a severe threat to public health and safety. All federal, state, city, and local regulations must be followed to obtain and maintain registration for the institution to conduct research involving BSAT. These include initial screening and continuous monitoring of personnel, controlled access to containment laboratories, accurate and current BSAT inventory records. Safety considerations are paramount in BSL-4 containment laboratories while considering the types of research tools, workflow and time required for conducting both in vivo and in vitro experiments in limited space. Required use of a positive-pressure encapsulating suit imposes tremendous physical limitations on the researcher. Successful mitigation of these constraints requires additional time, effort, good communication, and creative solutions. Test and evaluation of novel vaccines and therapeutics conducted under good laboratory practice (GLP conditions for FDA approval are prioritized and frequently share the same physical space with important ongoing basic research studies. The possibilities and limitations of biomedical research involving microbial pathogens of biodefense concern in BSL-4 containment laboratories are explored in this review.

  3. The Impact of Regulations, Safety Considerations and Physical Limitations on Research Progress at Maximum Biocontainment

    Science.gov (United States)

    Shurtleff, Amy C.; Garza, Nicole; Lackemeyer, Matthew; Carrion, Ricardo; Griffiths, Anthony; Patterson, Jean; Edwin, Samuel S.; Bavari, Sina

    2012-01-01

    We describe herein, limitations on research at biosafety level 4 (BSL-4) containment laboratories, with regard to biosecurity regulations, safety considerations, research space limitations, and physical constraints in executing experimental procedures. These limitations can severely impact the number of collaborations and size of research projects investigating microbial pathogens of biodefense concern. Acquisition, use, storage, and transfer of biological select agents and toxins (BSAT) are highly regulated due to their potential to pose a severe threat to public health and safety. All federal, state, city, and local regulations must be followed to obtain and maintain registration for the institution to conduct research involving BSAT. These include initial screening and continuous monitoring of personnel, controlled access to containment laboratories, accurate and current BSAT inventory records. Safety considerations are paramount in BSL-4 containment laboratories while considering the types of research tools, workflow and time required for conducting both in vivo and in vitro experiments in limited space. Required use of a positive-pressure encapsulating suit imposes tremendous physical limitations on the researcher. Successful mitigation of these constraints requires additional time, effort, good communication, and creative solutions. Test and evaluation of novel vaccines and therapeutics conducted under good laboratory practice (GLP) conditions for FDA approval are prioritized and frequently share the same physical space with important ongoing basic research studies. The possibilities and limitations of biomedical research involving microbial pathogens of biodefense concern in BSL-4 containment laboratories are explored in this review. PMID:23342380

  4. 40 CFR 130.7 - Total maximum daily loads (TMDL) and individual water quality-based effluent limitations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Total maximum daily loads (TMDL) and individual water quality-based effluent limitations. 130.7 Section 130.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS WATER QUALITY PLANNING AND MANAGEMENT § 130.7 Total...

  5. The limit distribution of the maximum increment of a random walk with regularly varying jump size distribution

    DEFF Research Database (Denmark)

    Mikosch, Thomas Valentin; Rackauskas, Alfredas

    2010-01-01

    In this paper, we deal with the asymptotic distribution of the maximum increment of a random walk with a regularly varying jump size distribution. This problem is motivated by a long-standing problem on change point detection for epidemic alternatives. It turns out that the limit distribution...... of the maximum increment of the random walk is one of the classical extreme value distributions, the Fréchet distribution. We prove the results in the general framework of point processes and for jump sizes taking values in a separable Banach space...

  6. Reliability of buildings in service limit state for maximum horizontal displacements

    Directory of Open Access Journals (Sweden)

    A. G. B. Corelhano

    Full Text Available Brazilian design code ABNT NBR6118:2003 - Design of Concrete Structures - Procedures - [1] proposes the use of simplified models for the consideration of non-linear material behavior in the evaluation of horizontal displacements in buildings. These models penalize stiffness of columns and beams, representing the effects of concrete cracking and avoiding costly physical non-linear analyses. The objectives of the present paper are to investigate the accuracy and uncertainty of these simplified models, as well as to evaluate the reliabilities of structures designed following ABNT NBR6118:2003[1&] in the service limit state for horizontal displacements. Model error statistics are obtained from 42 representative plane frames. The reliabilities of three typical (4, 8 and 12 floor buildings are evaluated, using the simplified models and a rigorous, physical and geometrical non-linear analysis. Results show that the 70/70 (column/beam stiffness reduction model is more accurate and less conservative than the 80/40 model. Results also show that ABNT NBR6118:2003 [1] design criteria for horizontal displacement limit states (masonry damage according to ACI 435.3R-68(1984 [10] are conservative, and result in reliability indexes which are larger than those recommended in EUROCODE [2] for irreversible service limit states.

  7. Maximum Entropy Production Modeling of Evapotranspiration Partitioning on Heterogeneous Terrain and Canopy Cover: advantages and limitations.

    Science.gov (United States)

    Gutierrez-Jurado, H. A.; Guan, H.; Wang, J.; Wang, H.; Bras, R. L.; Simmons, C. T.

    2015-12-01

    Quantification of evapotranspiration (ET) and its partition over regions of heterogeneous topography and canopy poses a challenge using traditional approaches. In this study, we report the results of a novel field experiment design guided by the Maximum Entropy Production model of ET (MEP-ET), formulated for estimating evaporation and transpiration from homogeneous soil and canopy. A catchment with complex terrain and patchy vegetation in South Australia was instrumented to measure temperature, humidity and net radiation at soil and canopy surfaces. Performance of the MEP-ET model to quantify transpiration and soil evaporation was evaluated during wet and dry conditions with independently and directly measured transpiration from sapflow and soil evaporation using the Bowen Ratio Energy Balance (BREB). MEP-ET transpiration shows remarkable agreement with that obtained through sapflow measurements during wet conditions, but consistently overestimates the flux during dry periods. However, an additional term introduced to the original MEP-ET model accounting for higher stomatal regulation during dry spells, based on differences between leaf and air vapor pressure deficits and temperatures, significantly improves the model performance. On the other hand, MEP-ET soil evaporation is in good agreement with that from BREB regardless of moisture conditions. The experimental design allows a plot and tree scale quantification of evaporation and transpiration respectively. This study confirms for the first time that the MEP-ET originally developed for homogeneous open bare soil and closed canopy can be used for modeling ET over heterogeneous land surfaces. Furthermore, we show that with the addition of an empirical function simulating the plants ability to regulate transpiration, and based on the same measurements of temperature and humidity, the method can produce reliable estimates of ET during both wet and dry conditions without compromising its parsimony.

  8. Experimental studies to validate model calculations and maximum solubility limits for Plutonium and Americium

    International Nuclear Information System (INIS)

    2017-01-01

    This report focuses on studies of KIT-INE to derive a significantly improved description of the chemical behaviour of Americium and Plutonium in saline NaCl, MgCl 2 and CaCl 2 brine systems. The studies are based on new experimental data and aim at deriving reliable Am and Pu solubility limits for the investigated systems as well as deriving comprehensive thermodynamic model descriptions. Both aspects are of high relevance in the context of potential source term estimations for Americium and Plutonium in aqueous brine systems and related scenarios. Americium and Plutonium are long-lived alpha emitting radionuclides which due to their high radiotoxicity need to be accounted for in a reliable and traceable way. The hydrolysis of trivalent actinides and the effect of highly alkaline pH conditions on the solubility of trivalent actinides in calcium chloride rich brine solutions were investigated and a thermodynamic model derived. The solubility of Plutonium in saline brine systems was studied under reducing and non-reducing conditions and is described within a new thermodynamic model. The influence of dissolved carbonate on Americium and Plutonium solubility in MgCl 2 solutions was investigated and quantitative information on Am and Pu solubility limits in these systems derived. Thermodynamic constants and model parameter derived in this work are implemented in the Thermodynamic Reference Database THEREDA owned by BfS. According to the quality assurance approach in THEREDA, is was necessary to publish parts of this work in peer-reviewed scientific journals. The publications are focused on solubility experiments, spectroscopy of aquatic and solid species and thermodynamic data. (Neck et al., Pure Appl. Chem., Vol. 81, (2009), pp. 1555-1568., Altmaier et al., Radiochimica Acta, 97, (2009), pp. 187-192., Altmaier et al., Actinide Research Quarterly, No 2., (2011), pp. 29-32.).

  9. 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)

  10. Hydraulic limits on maximum plant transpiration and the emergence of the safety-efficiency trade-off.

    Science.gov (United States)

    Manzoni, Stefano; Vico, Giulia; Katul, Gabriel; Palmroth, Sari; Jackson, Robert B; Porporato, Amilcare

    2013-04-01

    Soil and plant hydraulics constrain ecosystem productivity by setting physical limits to water transport and hence carbon uptake by leaves. While more negative xylem water potentials provide a larger driving force for water transport, they also cause cavitation that limits hydraulic conductivity. An optimum balance between driving force and cavitation occurs at intermediate water potentials, thus defining the maximum transpiration rate the xylem can sustain (denoted as E(max)). The presence of this maximum raises the question as to whether plants regulate transpiration through stomata to function near E(max). To address this question, we calculated E(max) across plant functional types and climates using a hydraulic model and a global database of plant hydraulic traits. The predicted E(max) compared well with measured peak transpiration across plant sizes and growth conditions (R = 0.86, P efficiency trade-off in plant xylem. Stomatal conductance allows maximum transpiration rates despite partial cavitation in the xylem thereby suggesting coordination between stomatal regulation and xylem hydraulic characteristics. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  11. Preliminary identification of the bioremediation limiting factors of a clay bearing soil contaminated with crude oil

    OpenAIRE

    Rizzo, Andréa C. L.; Cunha, Claudia D. da; Santos, Ronaldo L. C.; Santos, Renata M.; Magalhães, Hugo M.; Leite, Selma G. F.; Soriano, Adriana U.

    2008-01-01

    Bioremediation is an attractive alternative to treat soils contaminated with petroleum hydrocarbons. However, the effectiveness of biodegradation process can be limited by both contaminant characteristics and its bioavailability in soil. This work aims at establishing a preliminary procedure to identify the main factor (hydrocarbon recalcitrance or its bioavailability) that impairs the biodegradation, possibly resulting in low remediation efficiencies. Tests in soil microcosms were carried ou...

  12. Compact stars with a small electric charge: the limiting radius to mass relation and the maximum mass for incompressible matter

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Jose P.S.; Lopes, Francisco J.; Quinta, Goncalo [Universidade de Lisboa, UL, Departamento de Fisica, Centro Multidisciplinar de Astrofisica, CENTRA, Instituto Superior Tecnico, IST, Lisbon (Portugal); Zanchin, Vilson T. [Universidade Federal do ABC, Centro de Ciencias Naturais e Humanas, Santo Andre, SP (Brazil)

    2015-02-01

    One of the stiffest equations of state for matter in a compact star is constant energy density and this generates the interior Schwarzschild radius to mass relation and the Misner maximum mass for relativistic compact stars. If dark matter populates the interior of stars, and this matter is supersymmetric or of some other type, some of it possessing a tiny electric charge, there is the possibility that highly compact stars can trap a small but non-negligible electric charge. In this case the radius to mass relation for such compact stars should get modifications. We use an analytical scheme to investigate the limiting radius to mass relation and the maximum mass of relativistic stars made of an incompressible fluid with a small electric charge. The investigation is carried out by using the hydrostatic equilibrium equation, i.e., the Tolman-Oppenheimer-Volkoff (TOV) equation, together with the other equations of structure, with the further hypothesis that the charge distribution is proportional to the energy density. The approach relies on Volkoff and Misner's method to solve the TOV equation. For zero charge one gets the interior Schwarzschild limit, and supposing incompressible boson or fermion matter with constituents with masses of the order of the neutron mass one finds that the maximum mass is the Misner mass. For a small electric charge, our analytical approximating scheme, valid in first order in the star's electric charge, shows that the maximum mass increases relatively to the uncharged case, whereas the minimum possible radius decreases, an expected effect since the new field is repulsive, aiding the pressure to sustain the star against gravitational collapse. (orig.)

  13. A model for the derivation of new transport limits for non-fixed contamination

    International Nuclear Information System (INIS)

    Thierfeldt, S.; Lorenz, B.; Hesse, J.

    2004-01-01

    The IAEA Regulations for the Safe Transport of Radioactive Material contain requirements for contamination limits on packages and conveyances used for the transport of radioactive material. Current contamination limits for packages and conveyances under routine transport conditions have been derived from a model proposed by Fairbairn more than 40 years ago. This model has proven effective if used with pragmatism, but is based on very conservative as well as extremely simple assumptions which is in no way appropriate any more and which is not compatible with ICRP recommendations regarding radiation protection standards. Therefore, a new model has now been developed which reflects all steps of the transport process. The derivation of this model has been fostered by the IAEA by initiating a Co-ordinated Research Project. The results of the calculations using this model could be directly applied as new nuclide specific transport limits for the non-fixed contamination

  14. A model for the derivation of new transport limits for non-fixed contamination

    Energy Technology Data Exchange (ETDEWEB)

    Thierfeldt, S. [Brenk Systemplanung GmbH, Aachen (Germany); Lorenz, B. [GNS Gesellschaft fuer Nuklearservice, Essen (Germany); Hesse, J. [RWE Power AG, Essen (Germany)

    2004-07-01

    The IAEA Regulations for the Safe Transport of Radioactive Material contain requirements for contamination limits on packages and conveyances used for the transport of radioactive material. Current contamination limits for packages and conveyances under routine transport conditions have been derived from a model proposed by Fairbairn more than 40 years ago. This model has proven effective if used with pragmatism, but is based on very conservative as well as extremely simple assumptions which is in no way appropriate any more and which is not compatible with ICRP recommendations regarding radiation protection standards. Therefore, a new model has now been developed which reflects all steps of the transport process. The derivation of this model has been fostered by the IAEA by initiating a Co-ordinated Research Project. The results of the calculations using this model could be directly applied as new nuclide specific transport limits for the non-fixed contamination.

  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. Higher renewable energy integration into the existing energy system of Finland – Is there any maximum limit?

    International Nuclear Information System (INIS)

    Zakeri, Behnam; Syri, Sanna; Rinne, Samuli

    2015-01-01

    Finland is to increase the share of RES (renewable energy sources) up to 38% in final energy consumption by 2020. While benefiting from local biomass resources Finnish energy system is deemed to achieve this goal, increasing the share of other intermittent renewables is under development, namely wind power and solar energy. Yet the maximum flexibility of the existing energy system in integration of renewable energy is not investigated, which is an important step before undertaking new renewable energy obligations. This study aims at filling this gap by hourly analysis and comprehensive modeling of the energy system including electricity, heat, and transportation, by employing EnergyPLAN tool. Focusing on technical and economic implications, we assess the maximum potential of different RESs separately (including bioenergy, hydropower, wind power, solar heating and PV, and heat pumps), as well as an optimal mix of different technologies. Furthermore, we propose a new index for assessing the maximum flexibility of energy systems in absorbing variable renewable energy. The results demonstrate that wind energy can be harvested at maximum levels of 18–19% of annual power demand (approx. 16 TWh/a), without major enhancements in the flexibility of energy infrastructure. With today's energy demand, the maximum feasible renewable energy for Finland is around 44–50% by an optimal mix of different technologies, which promises 35% reduction in carbon emissions from 2012's level. Moreover, Finnish energy system is flexible to augment the share of renewables in gross electricity consumption up to 69–72%, at maximum. Higher shares of RES calls for lower energy consumption (energy efficiency) and more flexibility in balancing energy supply and consumption (e.g. by energy storage). - Highlights: • By hourly analysis, we model the whole energy system of Finland. • With existing energy infrastructure, RES (renewable energy sources) in primary energy cannot go beyond 50%.

  17. Contamination limits for real and personal property. Progress report, July--December 1975

    International Nuclear Information System (INIS)

    Healy, J.W.; Wenzel, W.J.

    1976-05-01

    Studies of surface contamination continued with an attempt to apply previous concepts. Revision of the proposed limit for plutonium in soils was started with major efforts on wind resuspension and the use of data on environmental lead to estimate intake by children

  18. 24 CFR 203.18c - One-time or up-front mortgage insurance premium excluded from limitations on maximum mortgage...

    Science.gov (United States)

    2010-04-01

    ... insurance premium excluded from limitations on maximum mortgage amounts. 203.18c Section 203.18c Housing and...-front mortgage insurance premium excluded from limitations on maximum mortgage amounts. After... LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES SINGLE FAMILY MORTGAGE...

  19. 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

  20. Paired maximum inspiratory and expiratory plain chest radiographs for assessment of airflow limitation in chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Takashi, E-mail: tkino@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Kawayama, Tomotaka, E-mail: kawayama_tomotaka@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Imamura, Youhei, E-mail: mamura_youhei@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Sakazaki, Yuki, E-mail: sakazaki@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Hirai, Ryo, E-mail: hirai_ryou@kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Ishii, Hidenobu, E-mail: shii_hidenobu@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Suetomo, Masashi, E-mail: jin_t_f_c@yahoo.co.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Matsunaga, Kazuko, E-mail: kmatsunaga@kouhoukai.or.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Azuma, Koichi, E-mail: azuma@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Fujimoto, Kiminori, E-mail: kimichan@med.kurume-u.ac.jp [Department of Radiology, Kurume University School of Medicine, Kurume (Japan); Hoshino, Tomoaki, E-mail: hoshino@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan)

    2015-04-15

    Highlights: •It is often to use computed tomography (CT) scan for diagnosis of chronic obstructive pulmonary disease. •CT scan is more expensive and higher. •A plane chest radiography more simple and cheap. Moreover, it is useful as detection of pulmonary emphysema, but not airflow limitation. •Our study demonstrated that the maximum inspiratory and expiratory plane chest radiography technique could detect severe airflow limitations. •We believe that the technique is helpful to diagnose the patients with chronic obstructive pulmonary disease. -- Abstract: Background: The usefulness of paired maximum inspiratory and expiratory (I/E) plain chest radiography (pCR) for diagnosis of chronic obstructive pulmonary disease (COPD) is still unclear. Objectives: We examined whether measurement of the I/E ratio using paired I/E pCR could be used for detection of airflow limitation in patients with COPD. Methods: Eighty patients with COPD (GOLD stage I = 23, stage II = 32, stage III = 15, stage IV = 10) and 34 control subjects were enrolled. The I/E ratios of frontal and lateral lung areas, and lung distance between the apex and base on pCR views were analyzed quantitatively. Pulmonary function parameters were measured at the same time. Results: The I/E ratios for the frontal lung area (1.25 ± 0.01), the lateral lung area (1.29 ± 0.01), and the lung distance (1.18 ± 0.01) were significantly (p < 0.05) reduced in COPD patients compared with controls (1.31 ± 0.02 and 1.38 ± 0.02, and 1.22 ± 0.01, respectively). The I/E ratios in frontal and lateral areas, and lung distance were significantly (p < 0.05) reduced in severe (GOLD stage III) and very severe (GOLD stage IV) COPD as compared to control subjects, although the I/E ratios did not differ significantly between severe and very severe COPD. Moreover, the I/E ratios were significantly correlated with pulmonary function parameters. Conclusions: Measurement of I/E ratios on paired I/E pCR is simple and

  1. Paired maximum inspiratory and expiratory plain chest radiographs for assessment of airflow limitation in chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    Kinoshita, Takashi; Kawayama, Tomotaka; Imamura, Youhei; Sakazaki, Yuki; Hirai, Ryo; Ishii, Hidenobu; Suetomo, Masashi; Matsunaga, Kazuko; Azuma, Koichi; Fujimoto, Kiminori; Hoshino, Tomoaki

    2015-01-01

    Highlights: •It is often to use computed tomography (CT) scan for diagnosis of chronic obstructive pulmonary disease. •CT scan is more expensive and higher. •A plane chest radiography more simple and cheap. Moreover, it is useful as detection of pulmonary emphysema, but not airflow limitation. •Our study demonstrated that the maximum inspiratory and expiratory plane chest radiography technique could detect severe airflow limitations. •We believe that the technique is helpful to diagnose the patients with chronic obstructive pulmonary disease. -- Abstract: Background: The usefulness of paired maximum inspiratory and expiratory (I/E) plain chest radiography (pCR) for diagnosis of chronic obstructive pulmonary disease (COPD) is still unclear. Objectives: We examined whether measurement of the I/E ratio using paired I/E pCR could be used for detection of airflow limitation in patients with COPD. Methods: Eighty patients with COPD (GOLD stage I = 23, stage II = 32, stage III = 15, stage IV = 10) and 34 control subjects were enrolled. The I/E ratios of frontal and lateral lung areas, and lung distance between the apex and base on pCR views were analyzed quantitatively. Pulmonary function parameters were measured at the same time. Results: The I/E ratios for the frontal lung area (1.25 ± 0.01), the lateral lung area (1.29 ± 0.01), and the lung distance (1.18 ± 0.01) were significantly (p < 0.05) reduced in COPD patients compared with controls (1.31 ± 0.02 and 1.38 ± 0.02, and 1.22 ± 0.01, respectively). The I/E ratios in frontal and lateral areas, and lung distance were significantly (p < 0.05) reduced in severe (GOLD stage III) and very severe (GOLD stage IV) COPD as compared to control subjects, although the I/E ratios did not differ significantly between severe and very severe COPD. Moreover, the I/E ratios were significantly correlated with pulmonary function parameters. Conclusions: Measurement of I/E ratios on paired I/E pCR is simple and

  2. Best Practices to Limit Contamination of Donor Milk in a Milk Bank.

    Science.gov (United States)

    Froh, Elizabeth B; Vanderpool, Jill; Spatz, Diane L

    2018-01-02

    Human milk donated to a milk bank can become contaminated in a number of ways, but processes exist to eradicate pathogenic bacterial growth. Donor human milk may be cultured before or after pasteurization or both. The purpose of this article is to describe standard operations of the Mothers' Milk Bank of the Children's Hospital of Philadelphia, best practices to limit the bacterial contamination of donor human milk, and implications for future research. Copyright © 2018 AWHONN, the Association of Women’s Health, Obstetric and Neonatal Nurses. Published by Elsevier Inc. All rights reserved.

  3. Further European initiatives and regulations concerning radiation protection: drinking water guideline, maximum permissible contamination in food products and feeding stuff; Weitere europaeische Initiativen und Regelungen im Strahlenschutz. Trinkwasserrichtlinie, maximal zulaessige Kontaminationswerte in Nahrungs- und Futtermitteln

    Energy Technology Data Exchange (ETDEWEB)

    Mundigl, Stefan [Europaeische Kommission, Generaldirektion Energie, Luxemburg (Luxembourg). Abt. D3 - Strahlenschutz, EUFO 4150

    2013-07-01

    The radiation protection community has observed intensively the development of basic safety standards concerning protection against hazards of ionizing radiation. The new core part of the European radiation protection legislation is complemented by several specialized regulations relevant for radiation protection. Besides the existing regulations in the field of emergency protection the European Commission initiated a drinking water guideline that will be published in the near future. Furthermore the European commission approved a revised regulation concerning the maximum permissible contamination limits for food products and feeding stuff in case of a future nuclear accident. Together with the new radiation protection basic standards a new complete, coherent and modernized European regulation package will be accomplished.

  4. Critical assessment of the available technologies for sanitation of contaminated soil and their limits of application

    International Nuclear Information System (INIS)

    Nussbaumer, M.; Glaeser, E.

    1993-01-01

    Sanitation of polluted land comprises safety measures and soil purification measures. Soil purification can take place either in situ, or on-site or off-site after digging up the contaminated soil. In-situ processes are soil deaeration, groundwater purification and biological methods. Soil deaeration is suited for volatile pollutants in the unsaturated zone of loose soils, while groundwater purification is commonly applied for water-soluble pollutants in the saturated zone of soils with a high k f value. On-site or off-site purification of contaminated soils can take place by thermal processes, by soil washing, by microorganisms, or by physical processes. Thermal processes have the widest range of applications; they are suited for most soils polluted with mostly organic pollutants, and the residual contamination is lowest. Soil washing is limited to sandy and noncohesive soils and for emulsifiable or elutable pollutants. Biological on-site and off-line methods are limited to biodegradable pollutants which are not in phase. Loosening agents may be added in order to overcome geotechnical limitations. Physical purification of soils is limited to specific applications e.g. removal of volatile hydrocarbons. (orig.) [de

  5. Limit values used in the European Union for managing excavated land and contaminated soils

    International Nuclear Information System (INIS)

    Soto Diaz, E.; Rodriguez Abad, R.

    2014-01-01

    In this paper, which is a summary of the minor thesis of the same title, a qualitative comparison is made between mean limit values applied in different member countries of the European Union (EU) for the proper management of excavated lands and contaminated soils. This management can be carried out as a byproduct through its reuse, recycling or previous treatment, or through its consideration as a waste and its subsequent admission to a particular type of landfill. Three types of comparisons of UE limit values are done in this paper: between those established in six member countries for the use of excavated lands as a byproduct, between those existing in 15 European countries for contaminated soils, and finally between those required in 12 EU countries for their land filling. (Author)

  6. Incorporating bioavailability into management limits for copper in sediments contaminated by antifouling paint used in aquaculture.

    Science.gov (United States)

    Simpson, Stuart L; Spadaro, David A; O'Brien, Dom

    2013-11-01

    Although now well embedded within many risk-based sediment quality guideline (SQG) frameworks, contaminant bioavailability is still often overlooked in assessment and management of contaminated sediments. To optimise management limits for metal contaminated sediments, we assess the appropriateness of a range methods for modifying SQGs based on bioavailability considerations. The impairment of reproduction of the amphipod, Melita plumulosa, and harpacticoid copepod, Nitocra spinipes, was assessed for sediments contaminated with copper from antifouling paint, located below aquaculture cages. The measurement of dilute acid-extractable copper (AE-Cu) was found to provide the most useful means for monitoring the risks posed by sediment copper and setting management limits. Acid-volatile sulfide was found to be ineffective as a SQG-modifying factor as these organisms live mostly at the more oxidised sediment water interface. SQGs normalised to %-silt/organic carbon were effective, but the benefits gained were too small to justify this approach. The effectiveness of SQGs based on AE-Cu was attributed to a small portion of the total copper being present in potentially bioavailable forms (typicallycopper was likely present as paint flakes in the form of copper (I) oxide, the active ingredient of the antifoulant formulation. While the concentrations of paint-associated copper are very high in some sediments, as the transformation of this form of copper to AE-Cu appears slow, monitoring and management limits should assess the more bioavailable AE-Cu forms, and further efforts be made to limit the release of paint particles into the environment. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  7. Derivation of recommended limits for radionuclide contamination of foods by the FAO

    International Nuclear Information System (INIS)

    Wirth, E.; Mueller, M.K.

    1986-01-01

    As a consequence of the reactor accident at Chernobyl, USSR, various countries defined limits for radioactive contamination of foods at different levels. These limits ranged from a few Bq iodine 131 or cesium 134 + 137/kg (Malaysia and Canada) to more than 1000 Bq/kg (Great Britain and France). These variations in limits hindered the movement of foods in international trade. For this reason the FAO convened an Expert Consultation to derive 'action levels' below which neither intervention nor constraint would be justified in terms of international movement and trade in food and drink. These limits are to find application in cases of widespread environmental contamination after an accidental release of radionuclides. They are not to be applied in cases of local release, e.g. in the vicinity of nuclear facilities. The derivation of 'action levels' by the FAO was based on the recommendations issued by the International Commission of Radiological Protection (ICRP) in May 1985. According to this recommendation the committed dose equivalent for the whole body should not exceed 5 mSv in the first and 1 mSv in the consecutive years. For radionuclides that preferentially irradiate individual organs, e.g. I131 in the thyroid, the dose equivalent to a specified organ may be used to derive limiting values. For individual organs limiting doses of 50 mSv/a and 10 mSv/a respectively were chosen

  8. Derivation of recommended limits for radionuclide contamination of foods by the FAO

    Energy Technology Data Exchange (ETDEWEB)

    Wirth, E; Mueller, M K [Institute for Radiation Hygiene, Federal Health Office, Neuherberg (Germany)

    1986-07-01

    As a consequence of the reactor accident at Chernobyl, USSR, various countries defined limits for radioactive contamination of foods at different levels. These limits ranged from a few Bq iodine 131 or cesium 134 + 137/kg (Malaysia and Canada) to more than 1000 Bq/kg (Great Britain and France). These variations in limits hindered the movement of foods in international trade. For this reason the FAO convened an Expert Consultation to derive 'action levels' below which neither intervention nor constraint would be justified in terms of international movement and trade in food and drink. These limits are to find application in cases of widespread environmental contamination after an accidental release of radionuclides. They are not to be applied in cases of local release, e.g. in the vicinity of nuclear facilities. The derivation of 'action levels' by the FAO was based on the recommendations issued by the International Commission of Radiological Protection (ICRP) in May 1985. According to this recommendation the committed dose equivalent for the whole body should not exceed 5 mSv in the first and 1 mSv in the consecutive years. For radionuclides that preferentially irradiate individual organs, e.g. I131 in the thyroid, the dose equivalent to a specified organ may be used to derive limiting values. For individual organs limiting doses of 50 mSv/a and 10 mSv/a respectively were chosen.

  9. Maximum heart rate in brown trout (Salmo trutta fario) is not limited by firing rate of pacemaker cells.

    Science.gov (United States)

    Haverinen, Jaakko; Abramochkin, Denis V; Kamkin, Andre; Vornanen, Matti

    2017-02-01

    Temperature-induced changes in cardiac output (Q̇) in fish are largely dependent on thermal modulation of heart rate (f H ), and at high temperatures Q̇ collapses due to heat-dependent depression of f H This study tests the hypothesis that firing rate of sinoatrial pacemaker cells sets the upper thermal limit of f H in vivo. To this end, temperature dependence of action potential (AP) frequency of enzymatically isolated pacemaker cells (pacemaker rate, f PM ), spontaneous beating rate of isolated sinoatrial preparations (f SA ), and in vivo f H of the cold-acclimated (4°C) brown trout (Salmo trutta fario) were compared under acute thermal challenges. With rising temperature, f PM steadily increased because of the acceleration of diastolic depolarization and shortening of AP duration up to the break point temperature (T BP ) of 24.0 ± 0.37°C, at which point the electrical activity abruptly ceased. The maximum f PM at T BP was much higher [193 ± 21.0 beats per minute (bpm)] than the peak f SA (94.3 ± 6.0 bpm at 24.1°C) or peak f H (76.7 ± 2.4 at 15.7 ± 0.82°C) (P brown trout in vivo. Copyright © 2017 the American Physiological Society.

  10. Recent developments on surface contamination limits for packages and conveyances in transport regulations

    International Nuclear Information System (INIS)

    Thierfeldt, S.; Woerlen, S.; Lorenz, B.; Schwarz, W.

    2009-01-01

    The IAEA Regulations for the Safe Transport of Radioactive Material [1] contain requirements for contamination limits on packages and conveyances used for the transport of radioactive material. Current contamination limits for packages and conveyances under routine transport conditions have been derived from a model proposed by Fairbairn nearly 50 years ago [3]. This model has proven effective if used with pragmatism, but is based on very conservative as well as extremely simple assumptions which is in no way appropriate any more and which is not compatible with ICRP recommendations regarding radiation protection standards. Therefore, a new model has been developed over the last 8 years which reflects all steps of the transport process. The derivation of this model has been fostered by the IAEA by initiating a Co-ordinated Research Project (see section 2). The results of the calculations using this model could be directly applied as new nuclide specific transport limits for the non-fixed contamination. A corresponding regulatory text has been drafted by an IAEA technical meeting TM-36514, which was held in Tokyo November 10-14, 2008 (see section 4). (orig.)

  11. Recent developments on surface contamination limits for packages and conveyances in transport regulations

    Energy Technology Data Exchange (ETDEWEB)

    Thierfeldt, S.; Woerlen, S. [Brenk Systemplanung GmbH, Aachen (Germany); Lorenz, B. [GNS Gesellschaft fuer Nuklear-Service mbH, Essen (Germany); Schwarz, W. [VGB PowerTech e.V., Essen (Germany)

    2009-07-01

    The IAEA Regulations for the Safe Transport of Radioactive Material [1] contain requirements for contamination limits on packages and conveyances used for the transport of radioactive material. Current contamination limits for packages and conveyances under routine transport conditions have been derived from a model proposed by Fairbairn nearly 50 years ago [3]. This model has proven effective if used with pragmatism, but is based on very conservative as well as extremely simple assumptions which is in no way appropriate any more and which is not compatible with ICRP recommendations regarding radiation protection standards. Therefore, a new model has been developed over the last 8 years which reflects all steps of the transport process. The derivation of this model has been fostered by the IAEA by initiating a Co-ordinated Research Project (see section 2). The results of the calculations using this model could be directly applied as new nuclide specific transport limits for the non-fixed contamination. A corresponding regulatory text has been drafted by an IAEA technical meeting TM-36514, which was held in Tokyo November 10-14, 2008 (see section 4). (orig.)

  12. Transport Limits for Non-Fixed Contamination: A Hazard to Optimization in Radioprotection

    International Nuclear Information System (INIS)

    Theis, S.; Lorenz, B.; Schwarz, W.

    2004-01-01

    Current contamination limits for packages and conveyances under routine transport conditions have been derived from the Fairbairn model more than 40 years ago. This model has proved to be effective if used with pragmatism, but conservative. In some countries the limits are handled as action levels. Actions are taken if contamination levels are exceeded, but instant reporting to authorities is only necessary if the excess is higher than a certain factor of e.g. 10. In countries like Germany the limits are regarded as strictly binding. As could be seen after contamination incidents with transport casks for spent fuel assembly, the reporting by the media and perception by the public was not in accordance with the real radiation risk, which could in any case be neglected. However, exceeding the limits by only one percent lead in some cases immediately to legal actions. To avoid such actions, any practice with relevance for possible contamination or decontamination must consider an additional safety margin which is usually a factor of 10. This results -by the definition of TS-R1 recommendations- in a complete removal of non fixed contamination. For two examples the tremendous amount of decontamination work as well as measurements, which are necessary to reach this aim, is quantified. The first example focuses on the clearance measurements of 20' standard ISO-containers, (which are used exclusively for the transport of radioactive materials,) as conveyances for shipment of radioactive packages. In the second example (a loaded cask awaiting shipment) such actions lead to a real operational exposure which -according to good health physics practice- should otherwise be subject to minimization. These information is compared with the results of an IAEA working group, which was set up in 2000 with the aim of remodeling the exposure conditions for all persons involved in the transport of radioactive material, even members of the public. This international group combined members

  13. Transport Limits for Non-Fixed Contamination: A Hazard to Optimization in Radioprotection

    Energy Technology Data Exchange (ETDEWEB)

    Theis, S.; Lorenz, B.; Schwarz, W.

    2004-07-01

    Current contamination limits for packages and conveyances under routine transport conditions have been derived from the Fairbairn model more than 40 years ago. This model has proved to be effective if used with pragmatism, but conservative. In some countries the limits are handled as action levels. Actions are taken if contamination levels are exceeded, but instant reporting to authorities is only necessary if the excess is higher than a certain factor of e.g. 10. In countries like Germany the limits are regarded as strictly binding. As could be seen after contamination incidents with transport casks for spent fuel assembly, the reporting by the media and perception by the public was not in accordance with the real radiation risk, which could in any case be neglected. However, exceeding the limits by only one percent lead in some cases immediately to legal actions. To avoid such actions, any practice with relevance for possible contamination or decontamination must consider an additional safety margin which is usually a factor of 10. This results -by the definition of TS-R1 recommendations- in a complete removal of non fixed contamination. For two examples the tremendous amount of decontamination work as well as measurements, which are necessary to reach this aim, is quantified. The first example focuses on the clearance measurements of 20' standard ISO-containers, (which are used exclusively for the transport of radioactive materials,) as conveyances for shipment of radioactive packages. In the second example (a loaded cask awaiting shipment) such actions lead to a real operational exposure which -according to good health physics practice- should otherwise be subject to minimization. These information is compared with the results of an IAEA working group, which was set up in 2000 with the aim of remodeling the exposure conditions for all persons involved in the transport of radioactive material, even members of the public. This international group combined

  14. Transport methods: general. 6. A Flux-Limited Diffusion Theory Derived from the Maximum Entropy Eddington Factor

    International Nuclear Information System (INIS)

    Yin, Chukai; Su, Bingjing

    2001-01-01

    The Minerbo's maximum entropy Eddington factor (MEEF) method was proposed as a low-order approximation to transport theory, in which the first two moment equations are closed for the scalar flux f and the current F through a statistically derived nonlinear Eddington factor f. This closure has the ability to handle various degrees of anisotropy of angular flux and is well justified both numerically and theoretically. Thus, a lot of efforts have been made to use this approximation in transport computations, especially in the radiative transfer and astrophysics communities. However, the method suffers numerical instability and may lead to anomalous solutions if the equations are solved by certain commonly used (implicit) mesh schemes. Studies on numerical stability in one-dimensional cases show that the MEEF equations can be solved satisfactorily by an implicit scheme (of treating δΦ/δx) if the angular flux is not too anisotropic so that f 32 , the classic diffusion solution P 1 , the MEEF solution f M obtained by Riemann solvers, and the NFLD solution D M for the two problems, respectively. In Fig. 1, NFLD and MEEF quantitatively predict very close results. However, the NFLD solution is qualitatively better because it is continuous while MEEF predicts unphysical jumps near the middle of the slab. In Fig. 2, the NFLD and MEEF solutions are almost identical, except near the material interface. In summary, the flux-limited diffusion theory derived from the MEEF description is quantitatively as accurate as the MEEF method. However, it is more qualitatively correct and user-friendly than the MEEF method and can be applied efficiently to various steady-state problems. Numerical tests show that this method is widely valid and overall predicts better results than other low-order approximations for various kinds of problems, including eigenvalue problems. Thus, it is an appealing approximate solution technique that is fast computationally and yet is accurate enough for a

  15. Methods to assess bioavailability of hydrophobic organic contaminants: Principles, operations, and limitations.

    Science.gov (United States)

    Cui, Xinyi; Mayer, Philipp; Gan, Jay

    2013-01-01

    Many important environmental contaminants are hydrophobic organic contaminants (HOCs), which include PCBs, PAHs, PBDEs, DDT and other chlorinated insecticides, among others. Owing to their strong hydrophobicity, HOCs have their final destination in soil or sediment, where their ecotoxicological effects are closely regulated by sorption and thus bioavailability. The last two decades have seen a dramatic increase in research efforts in developing and applying partitioning based methods and biomimetic extractions for measuring HOC bioavailability. However, the many variations of both analytical methods and associated measurement endpoints are often a source of confusion for users. In this review, we distinguish the most commonly used analytical approaches based on their measurement objectives, and illustrate their practical operational steps, strengths and limitations using simple flowcharts. This review may serve as guidance for new users on the selection and use of established methods, and a reference for experienced investigators to identify potential topics for further research. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. The limit distribution of the maximum increment of a random walk with dependent regularly varying jump sizes

    DEFF Research Database (Denmark)

    Mikosch, Thomas Valentin; Moser, Martin

    2013-01-01

    We investigate the maximum increment of a random walk with heavy-tailed jump size distribution. Here heavy-tailedness is understood as regular variation of the finite-dimensional distributions. The jump sizes constitute a strictly stationary sequence. Using a continuous mapping argument acting...... on the point processes of the normalized jump sizes, we prove that the maximum increment of the random walk converges in distribution to a Fréchet distributed random variable....

  17. 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.

  18. Understanding the Benefits and Limitations of Increasing Maximum Rotor Tip Speed for Utility-Scale Wind Turbines

    International Nuclear Information System (INIS)

    Ning, A; Dykes, K

    2014-01-01

    For utility-scale wind turbines, the maximum rotor rotation speed is generally constrained by noise considerations. Innovations in acoustics and/or siting in remote locations may enable future wind turbine designs to operate with higher tip speeds. Wind turbines designed to take advantage of higher tip speeds are expected to be able to capture more energy and utilize lighter drivetrains because of their decreased maximum torque loads. However, the magnitude of the potential cost savings is unclear, and the potential trade-offs with rotor and tower sizing are not well understood. A multidisciplinary, system-level framework was developed to facilitate wind turbine and wind plant analysis and optimization. The rotors, nacelles, and towers of wind turbines are optimized for minimum cost of energy subject to a large number of structural, manufacturing, and transportation constraints. These optimization studies suggest that allowing for higher maximum tip speeds could result in a decrease in the cost of energy of up to 5% for land-based sites and 2% for offshore sites when using current technology. Almost all of the cost savings are attributed to the decrease in gearbox mass as a consequence of the reduced maximum rotor torque. Although there is some increased energy capture, it is very minimal (less than 0.5%). Extreme increases in tip speed are unnecessary; benefits for maximum tip speeds greater than 100-110 m/s are small to nonexistent

  19. Understanding the Benefits and Limitations of Increasing Maximum Rotor Tip Speed for Utility-Scale Wind Turbines

    Science.gov (United States)

    Ning, A.; Dykes, K.

    2014-06-01

    For utility-scale wind turbines, the maximum rotor rotation speed is generally constrained by noise considerations. Innovations in acoustics and/or siting in remote locations may enable future wind turbine designs to operate with higher tip speeds. Wind turbines designed to take advantage of higher tip speeds are expected to be able to capture more energy and utilize lighter drivetrains because of their decreased maximum torque loads. However, the magnitude of the potential cost savings is unclear, and the potential trade-offs with rotor and tower sizing are not well understood. A multidisciplinary, system-level framework was developed to facilitate wind turbine and wind plant analysis and optimization. The rotors, nacelles, and towers of wind turbines are optimized for minimum cost of energy subject to a large number of structural, manufacturing, and transportation constraints. These optimization studies suggest that allowing for higher maximum tip speeds could result in a decrease in the cost of energy of up to 5% for land-based sites and 2% for offshore sites when using current technology. Almost all of the cost savings are attributed to the decrease in gearbox mass as a consequence of the reduced maximum rotor torque. Although there is some increased energy capture, it is very minimal (less than 0.5%). Extreme increases in tip speed are unnecessary; benefits for maximum tip speeds greater than 100-110 m/s are small to nonexistent.

  20. The distribution of 137Cs in maize (Zea mays L.) and two millet species (Panicum miliaceum L. and Panicum maximum Jacq.) cultivated on the cesium-contaminated soil

    International Nuclear Information System (INIS)

    Bystrzejewska-Nowacka, G.; Nowacka, R.

    2004-01-01

    The plant of three species (Zea mays L., Panicum miliaceum L. and Panicum maximum Jacq.) were grown on the soil contaminated with 0.3 mM CsCl solution traced with 137 Cs, in greenhouse. For all the species, the fresh-to-dry weight ratio was equal in the cesium-treated plants and in the central group after 3 weeks of culture. The shoot-to root fresh weight and dry weight ratios were decreased in maize, unchanged in Panicum miliaceum and increased in Panicum maximum, comparing to the control without cesium treatment. The shoot/soil and also root/soil transfer (TF) for 137 Cs (measured by means of Na I gamma spectrometer) were always the highest in maize, then lower in Panicum miliaceum and the lowest in Panicum maximum. All the plants seem to be hyperaccumulators of cesium. The root/soil Tf was especially high in maize, i.e. 55 (kBq kg -1 biomass)/kBq Kg -1 soil). The shoot/root concentration factor (CF) for 137 Cs was the lowest in maize, higher in Panicum miliaceum and highest in Panicum maximum. The proved ability of the investigated plants for phytoextraction of the soil cesium points to the (author). The detectability and reliin soil bioremediation. From this point of view, Panicum maximum seems to be the most useful plant because it accumulates cesium mainly in the shoot, and maize would be the least useful spices since it has the highest accumulation in root. (author)

  1. Methods to assess bioavailability of hydrophobic organic contaminants: Principles, operations, and limitations

    International Nuclear Information System (INIS)

    Cui Xinyi; Mayer, Philipp; Gan, Jay

    2013-01-01

    Many important environmental contaminants are hydrophobic organic contaminants (HOCs), which include PCBs, PAHs, PBDEs, DDT and other chlorinated insecticides, among others. Owing to their strong hydrophobicity, HOCs have their final destination in soil or sediment, where their ecotoxicological effects are closely regulated by sorption and thus bioavailability. The last two decades have seen a dramatic increase in research efforts in developing and applying partitioning based methods and biomimetic extractions for measuring HOC bioavailability. However, the many variations of both analytical methods and associated measurement endpoints are often a source of confusion for users. In this review, we distinguish the most commonly used analytical approaches based on their measurement objectives, and illustrate their practical operational steps, strengths and limitations using simple flowcharts. This review may serve as guidance for new users on the selection and use of established methods, and a reference for experienced investigators to identify potential topics for further research. - This review summarizes the principles and operations of bioavailability prediction methods, discusses their strengths and limitations, and highlights issues for future research.

  2. Tenax TA extraction to understand the rate-limiting factors in methyl-β-cyclodextrin-enhanced bioremediation of PAH-contaminated soil.

    Science.gov (United States)

    Sun, Mingming; Luo, Yongming; Teng, Ying; Christie, Peter; Jia, Zhongjun; Li, Zhengao

    2013-06-01

    The effectiveness of many bioremediation systems for PAH-contaminated soil may be constrained by low contaminant bioaccessibility due to limited aqueous solubility or large sorption capacity. Information on the extent to which PAHs can be readily biodegraded is of vital importance in the decision whether or not to remediate a contaminated soil. In the present study the rate-limiting factors in methyl-β-cyclodextrin (MCD)-enhanced bioremediation of PAH-contaminated soil were evaluated. MCD amendment at 10 % (w/w) combined with inoculation with the PAH-degrading bacterium Paracoccus sp. strain HPD-2 produced maximum removal of total PAHs of up to 35 %. The desorption of PAHs from contaminated soil was determined before and after 32 weeks of bioremediation. 10 % (w/w) MCD amendment (M2) increased the Tenax extraction of total PAHs from 12 to 30 % and promoted degradation by up to 26 % compared to 6 % in the control. However, the percentage of Tenax extraction for total PAHs was much larger than that of degradation. Thus, in the control and M2 treatment it is likely that during the initial phase the bioaccessibility of PAHs is high and biodegradation rates may be limited by microbial processes. On the other hand, when the soil was inoculated with the PAH-degrading bacterium (CKB and MB2), the slowly and very slowly desorbing fractions (F sl and F vl ) became larger and the rate constants of slow and very slow desorption (k sl and k vl ) became extremely small after bioremediation, suggesting that desorption is likely rate limiting during the second, slow phase of biotransformation. These results have practical implications for site risk assessment and cleanup strategies.

  3. 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

  4. The two-box model of climate: limitations and applications to planetary habitability and maximum entropy production studies.

    Science.gov (United States)

    Lorenz, Ralph D

    2010-05-12

    The 'two-box model' of planetary climate is discussed. This model has been used to demonstrate consistency of the equator-pole temperature gradient on Earth, Mars and Titan with what would be predicted from a principle of maximum entropy production (MEP). While useful for exposition and for generating first-order estimates of planetary heat transports, it has too low a resolution to investigate climate systems with strong feedbacks. A two-box MEP model agrees well with the observed day : night temperature contrast observed on the extrasolar planet HD 189733b.

  5. Molecular analysis of phosphate limitation in Geobacteraceae during the bioremediation of a uranium-contaminated aquifer

    Energy Technology Data Exchange (ETDEWEB)

    N' Guessan, L.A.; Elifantz, H.; Nevin, K.P.; Mouser, P.J.; Methe, B.; Woodard, T. L.; Manley, K.; Williams, K. H.; Wilkins, M. J.; Larsen, J.T.; Long, P. E.; Lovley, D. R.

    2009-09-01

    Nutrient limitation is an environmental stress that may reduce the effectiveness of bioremediation strategies, especially when the contaminants are organic compounds or when organic compounds are added to promote microbial activities such as metal reduction. Genes indicative of phosphate-limitation were identified via microarray analysis of chemostat cultures of Geobacter sulfureducens. This analysis revealed that genes in the pst-pho operon, which is associated with a high affinity phosphate uptake system in other microorganisms, had significantly higher transcript abundance under phosphate-limiting conditions, with the genes pstB and phoU the most up-regulated. Quantitative PCR analysis of pstB and phoU transcript levels in G. sulfurreducens grown in chemostats demonstrated that the expression of these genes increased when phosphate was removed from the culture medium. Transcripts of pstB and phoU within the subsurface Geobacter species predominating during an in situ uranium bioremediation field experiment were more abundant than in chemostat cultures of G. sulfurreducens that were not limited for phosphate. Addition of phosphate to incubations of subsurface sediments did not stimulate dissimilatory metal reduction. The added phosphate was rapidly adsorbed onto the sediments. The results demonstrate that Geobacter species can effectively reduce U(VI) even when experiencing suboptimal phosphate concentrations and that increasing phosphate availability with phosphate additions is difficult to achieve due to the high reactivity of this compound. This transcript-based approach developed for diagnosing phosphate limitation should be applicable to assessing the potential need for additional phosphate in other bioremediation processes.

  6. CORRELATION BETWEEN PATHOLOGY AND EXCESS OF MAXIMUM CONCENTRATION LIMIT OF POLLUTANTS IN THE ENVIRONMENT OF THE REPUBLIC OF DAGESTAN

    Directory of Open Access Journals (Sweden)

    G. M. Abdurakhmanov

    2013-01-01

    Full Text Available Abstract. Statistical data from "Indicators of health status of the Republic of Dagestan" for 1999 - 2010 years are presented in the work. The aim of this work was to identify a cause-effect correlation between non-communicable diseases (ischemic heart disease, neuropsychiatric disease, endemic goiter, diabetes, congenital anomalies and environmental factors in the Republic of Dagestan.Statistical data processing was carried out using the software package Statistica, Microsoft Excel. The Spearman rank correlation coefficient (ρ was used for identify of correlation between indicators of environmental quality and health of population.Moderate positive correlation is observed between the development of pathology and excess of concentrations of contaminants in drinking water sources. Direct correlations are founded between development of the studied pathologies and excess of concentrations of heavy metals and their mobile forms in soils of the region. Direct correlation is found between excess of concentrations of heavy metals in the pasture vegetation (factorial character and the morbidity of the population (effective character.

  7. Using information and communication technology (ICT) to the maximum: learning and teaching biology with limited digital technologies

    Science.gov (United States)

    Van Rooy, Wilhelmina S.

    2012-04-01

    Background: The ubiquity, availability and exponential growth of digital information and communication technology (ICT) creates unique opportunities for learning and teaching in the senior secondary school biology curriculum. Digital technologies make it possible for emerging disciplinary knowledge and understanding of biological processes previously too small, large, slow or fast to be taught. Indeed, much of bioscience can now be effectively taught via digital technology, since its representational and symbolic forms are in digital formats. Purpose: This paper is part of a larger Australian study dealing with the technologies and modalities of learning biology in secondary schools. Sample: The classroom practices of three experienced biology teachers, working in a range of NSW secondary schools, are compared and contrasted to illustrate how the challenges of limited technologies are confronted to seamlessly integrate what is available into a number of molecular genetics lessons to enhance student learning. Design and method: The data are qualitative and the analysis is based on video classroom observations and semi-structured teacher interviews. Results: Findings indicate that if professional development opportunities are provided where the pedagogy of learning and teaching of both the relevant biology and its digital representations are available, then teachers see the immediate pedagogic benefit to student learning. In particular, teachers use ICT for challenging genetic concepts despite limited computer hardware and software availability. Conclusion: Experienced teachers incorporate ICT, however limited, in order to improve the quality of student learning.

  8. Modelling approach to limit aflatoxin B1 contamination in dairy cattle compound feed

    NARCIS (Netherlands)

    Bouzembrak, Y.; Fels-Klerx, van der H.J.

    2016-01-01

    Feeding dairy cattle with safe compound feed helps farmers to ensure food safety. However, several ingredients often used in compound feed production can be contaminated with aflatoxin B1 (AFB1), which may result into milk contaminated with aflatoxin M1. Given the number of ingredients and their

  9. Approach to calculating upper bounds on maximum individual doses from the use of contaminated well water following a WIPP repository breach. Report EEG-9

    International Nuclear Information System (INIS)

    Spiegler, P.

    1981-09-01

    As part of the assessment of the potential radiological consequences of the proposed Waste Isolation Pilot Plant (WIPP), this report evaluates the post-closure radiation dose commitments associated with a possible breach event which involves dissolution of the repository by groundwaters and subsequent transport of the nuclear waste through an aquifer to a well assumed to exist at a point 3 miles downstream from the repository. The concentrations of uranium and plutonium isotopes at the well are based on the nuclear waste inventory presently proposed for WIPP and basic assumptions concerning the transport of waste as well as treatment to reduce the salinity of the water. The concentrations of U-233, Pu-239, and Pu-240, all radionuclides originally emplaced as waste in the repository, would exceed current EPA drinking water limits. The concentrations of U-234, U-235, and U-236, all decay products of plutonium isotopes originally emplaced as waste, would be well below current EPA drinking water limits. The 50-year dose commitments from one year of drinking treated water contaminated with U-233 or Pu-239 and Pu-240 were found to be comparable to a one-year dose from natural background. The 50-year dose commitments from one year of drinking milk would be no more than about 1/5 the dose obtained from ingestion of treated water. These doses are considered upper bounds because of several very conservative assumptions which are discussed in the report

  10. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

  11. Laboratory Evaluation of Light Obscuration Particle Counter Contamination Limits for Aviation Fuel

    Science.gov (United States)

    2015-11-01

    assurance testing though conducting periodic fuel sampling for gravimetric analysis. The Army currently utilizes two methods for measuring particulate...contamination by gravimetric analysis: ASTM D2276 - Standard Test Method for Particulate Contaminant in Aviation Fuel by Line Sampling, and ASTM D5452...while filter effectiveness is checked every 30 days by gravimetric analysis (ASTM D2276). One of the problems with the gravimetric methods is the

  12. Contamination limits for real and personal property. Progress report, January--June 1975

    International Nuclear Information System (INIS)

    Wenzel, W.J.; Healy, J.W.

    1975-10-01

    Data for the movement of various contaminants ( 89 Sr, 131 I, 32 P) from several different laboratory surface materials and textiles were examined and the fractional amount removed per unit time fitted to an arbitrary scale of level of action. Both the nature of the contaminant and the nature of the surface appear to affect the fractional removal although data are not available to define the dependence in any detail

  13. Contribution to the study of maximum levels for liquid radioactive waste disposal into continental and sea water. Treatment of some typical samples; Contribution a l'etude des niveaux limites relatifs a des rejets d'effluents radioactifs liquides dans les eaux continentales et oceaniques. Traitement de quelques exemples types

    Energy Technology Data Exchange (ETDEWEB)

    Bittel, R; Mancel, J [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires, departement de la protection sanitaire

    1968-10-01

    The most important carriers of radioactive contamination of man are the whole of foodstuffs and not only ingested water or inhaled air. That is the reason why, in accordance with the spirit of the recent recommendations of the ICRP, it is proposed to substitute the idea of maximum levels of contamination of water to the MPC. In the case of aquatic food chains (aquatic organisms and irrigated foodstuffs), the knowledge of the ingested quantities and of the concentration factors food/water permit to determinate these maximum levels, or to find out a linear relation between the maximum levels in the case of two primary carriers of contamination (continental and sea waters). The notion of critical food-consumption, critical radioelements and formula of waste disposal are considered in the same way, taking care to attach the greatest possible importance to local situations. (authors) [French] Les vecteurs essentiels de la contamination radioactive de l'homme sont les aliments dans leur ensemble, et non seulement l'eau ingeree ou l'air inhale. C'est pourquoi, en accord avec l'esprit des recentes recommandations de la C.I.P.R., il est propose de substituer aux CMA la notion de niveaux limites de contamination des eaux. Dans le cas des chaines alimentaires aquatiques (organismes aquatiques et aliments irrigues), la connaissance des quantites ingerees et celle des facteurs de concentration aliments/eau permettent de determiner ces niveaux limites dans le cas de deux vecteurs primaires de contamination (eaux continentales et eaux oceaniques). Les notions de regime alimentaire critique, de radioelement critique et de formule de rejets sont envisagees, dans le meme esprit, avec le souci de tenir compte le plus possible des situations locales. (auteurs)

  14. 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

  15. Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario

    International Nuclear Information System (INIS)

    Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai

    2014-01-01

    In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates. (paper)

  16. Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario.

    Science.gov (United States)

    Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai

    2014-07-07

    In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates.

  17. Development and Performance of Detectors for the Cryogenic Dark Matter Search Experiment with an Increased Sensitivity Based on a Maximum Likelihood Analysis of Beta Contamination

    Energy Technology Data Exchange (ETDEWEB)

    Driscoll, Donald D [Case Western Reserve Univ., Cleveland, OH (United States)

    2004-05-01

    The Cryogenic Dark Matter Search (CDMS) uses cryogenically-cooled detectors made of germanium and silicon in an attempt to detect dark matter in the form of Weakly-Interacting Massive Particles (WIMPs). The expected interaction rate of these particles is on the order of 1/kg/day, far below the 200/kg/day expected rate of background interactions after passive shielding and an active cosmic ray muon veto. Our detectors are instrumented to make a simultaneous measurement of both the ionization energy and thermal energy deposited by the interaction of a particle with the crystal substrate. A comparison of these two quantities allows for the rejection of a background of electromagnetically-interacting particles at a level of better than 99.9%. The dominant remaining background at a depth of ~ 11 m below the surface comes from fast neutrons produced by cosmic ray muons interacting in the rock surrounding the experiment. Contamination of our detectors by a beta emitter can add an unknown source of unrejected background. In the energy range of interest for a WIMP study, electrons will have a short penetration depth and preferentially interact near the surface. Some of the ionization signal can be lost to the charge contacts there and a decreased ionization signal relative to the thermal signal will cause a background event which interacts at the surface to be misidentified as a signal event. We can use information about the shape of the thermal signal pulse to discriminate against these surface events. Using a subset of our calibration set which contains a large fraction of electron events, we can characterize the expected behavior of surface events and construct a cut to remove them from our candidate signal events. This thesis describes the development of the 6 detectors (4 x 250 g Ge and 2 x 100 g Si) used in the 2001-2002 CDMS data run at the Stanford Underground Facility with a total of 119 livedays of data. The preliminary results presented are based on the first use

  18. Contamination limits for real and personal property. Progress report, July--December 1974

    International Nuclear Information System (INIS)

    Healy, J.W.; Wenzel, W.J.

    1975-05-01

    Studies during this period were primarily devoted to the derivation of a simplified conceptual model of radiation doses resulting from contaminated objects. A four-part model consisting of sections on use, actions, pathways, and radiation dose is described. This model will permit study of the quantitative features for each part. (U.S.)

  19. Improved management of winter operations to limit subsurface contamination with degradable deicing chemicals in cold regions.

    Science.gov (United States)

    French, Helen K; van der Zee, Sjoerd E A T M

    2014-01-01

    This paper gives an overview of management considerations required for better control of deicing chemicals in the unsaturated zone at sites with winter maintenance operations in cold regions. Degradable organic deicing chemicals are the main focus. The importance of the heterogeneity of both the infiltration process, due to frozen ground and snow melt including the contact between the melting snow cover and the soil, and unsaturated flow is emphasised. In this paper, the applicability of geophysical methods for characterising soil heterogeneity is considered, aimed at modelling and monitoring changes in contamination. To deal with heterogeneity, a stochastic modelling framework may be appropriate, emphasizing the more robust spatial and temporal moments. Examples of a combination of different field techniques for measuring subsoil properties and monitoring contaminants and integration through transport modelling are provided by the SoilCAM project and previous work. Commonly, the results of flow and contaminant fate modelling are quite detailed and complex and require post-processing before communication and advising stakeholders. The managers' perspectives with respect to monitoring strategies and challenges still unresolved have been analysed with basis in experience with research collaboration with one of the case study sites, Oslo airport, Gardermoen, Norway. Both scientific challenges of monitoring subsoil contaminants in cold regions and the effective interaction between investigators and management are illustrated.

  20. Characterizing, for packaging and transport, large objects contaminated by radioactive material having a limited A2 value

    International Nuclear Information System (INIS)

    Pope, R.B.; Shappert, L.B.; Michelhaugh, R.D.; Cash, J.M.; Best, R.E.

    1998-02-01

    The International Atomic Energy Agency (IAEA) Regulations for the safe packaging and transportation of radioactive materials follow a graded approach to the requirements for both packaging and controls during transport. The concept is that, the lower the risk posed to the people and the environment by the contents, (1) the less demanding are the packaging requirements and (2) the smaller in number are the controls imposed on the transport of the material. There are likely to be a great number of situations arising in coming years when large objects, contaminated with radioactive material having unlimited A 2 values will result from various decommissioning and decontamination (D and D) activities and will then require shipment from the D and D site to a disposal site. Such situations may arise relatively frequently during the cleanup of operations involving mining, milling, feedstock, and uranium enrichment processing facilities. Because these objects are contaminated with materials having an unlimited A 2 value they present a low radiological risk to worker and public safety and to the environment during transport. However, when these radioactive materials reside on the surfaces of equipment and other large objects, where the equipment and objects themselves are not radioactive, the radioactive materials appear as surface contamination and, if the contaminated object is categorized as a surface contaminated object, it would need to be packaged for shipment according to the requirements of the Regulations for SCO. Despite this categorization, alternatives may be available which will allow these contaminants, when considered by themselves for packaging and transport, to be categorized as either (1) a limited quantity of radioactive material to be shipped in an excepted package or (2) low specific activity (LSA) materials to be shipped in an IP-1 package or possibly even shipped unpackaged. These options are discussed in this paper

  1. 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.

  2. Are inundation limit and maximum extent of sand useful for differentiating tsunamis and storms? An example from sediment transport simulations on the Sendai Plain, Japan

    Science.gov (United States)

    Watanabe, Masashi; Goto, Kazuhisa; Bricker, Jeremy D.; Imamura, Fumihiko

    2018-02-01

    We examined the quantitative difference in the distribution of tsunami and storm deposits based on numerical simulations of inundation and sediment transport due to tsunami and storm events on the Sendai Plain, Japan. The calculated distance from the shoreline inundated by the 2011 Tohoku-oki tsunami was smaller than that inundated by storm surges from hypothetical typhoon events. Previous studies have assumed that deposits observed farther inland than the possible inundation limit of storm waves and storm surge were tsunami deposits. However, confirming only the extent of inundation is insufficient to distinguish tsunami and storm deposits, because the inundation limit of storm surges may be farther inland than that of tsunamis in the case of gently sloping coastal topography such as on the Sendai Plain. In other locations, where coastal topography is steep, the maximum inland inundation extent of storm surges may be only several hundred meters, so marine-sourced deposits that are distributed several km inland can be identified as tsunami deposits by default. Over both gentle and steep slopes, another difference between tsunami and storm deposits is the total volume deposited, as flow speed over land during a tsunami is faster than during a storm surge. Therefore, the total deposit volume could also be a useful proxy to differentiate tsunami and storm deposits.

  3. Impacts of trace carbon on the microstructure of as-sintered biomedical Ti-15Mo alloy and reassessment of the maximum carbon limit.

    Science.gov (United States)

    Yan, M; Qian, M; Kong, C; Dargusch, M S

    2014-02-01

    The formation of grain boundary (GB) brittle carbides with a complex three-dimensional (3-D) morphology can be detrimental to both the fatigue properties and corrosion resistance of a biomedical titanium alloy. A detailed microscopic study has been performed on an as-sintered biomedical Ti-15Mo (in wt.%) alloy containing 0.032 wt.% C. A noticeable presence of a carbon-enriched phase has been observed along the GB, although the carbon content is well below the maximum carbon limit of 0.1 wt.% specified by ASTM Standard F2066. Transmission electron microscopy (TEM) identified that the carbon-enriched phase is face-centred cubic Ti2C. 3-D tomography reconstruction revealed that the Ti2C structure has morphology similar to primary α-Ti. Nanoindentation confirmed the high hardness and high Young's modulus of the GB Ti2C phase. To avoid GB carbide formation in Ti-15Mo, the carbon content should be limited to 0.006 wt.% by Thermo-Calc predictions. Similar analyses and characterization of the carbide formation in biomedical unalloyed Ti, Ti-6Al-4V and Ti-16Nb have also been performed. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Studying DDT Susceptibility at Discriminating Time Intervals Focusing on Maximum Limit of Exposure Time Survived by DDT Resistant Phlebotomus argentipes (Diptera: Psychodidae): an Investigative Report.

    Science.gov (United States)

    Rama, Aarti; Kesari, Shreekant; Das, Pradeep; Kumar, Vijay

    2017-07-24

    Extensive application of routine insecticide i.e., dichlorodiphenyltrichloroethane (DDT) to control Phlebotomus argentipes (Diptera: Psychodidae), the proven vector of visceral leishmaniasis in India, had evoked the problem of resistance/tolerance against DDT, eventually nullifying the DDT dependent strategies to control this vector. Because tolerating an hour-long exposure to DDT is not challenging enough for the resistant P. argentipes, estimating susceptibility by exposing sand flies to insecticide for just an hour becomes a trivial and futile task.Therefore, this bioassay study was carried out to investigate the maximum limit of exposure time to which DDT resistant P. argentipes can endure the effect of DDT for their survival. The mortality rate of laboratory-reared DDT resistant strain P. argentipes exposed to DDT was studied at discriminating time intervals of 60 min and it was concluded that highly resistant sand flies could withstand up to 420 min of exposure to this insecticide. Additionally, the lethal time for female P. argentipes was observed to be higher than for males suggesting that they are highly resistant to DDT's toxicity. Our results support the monitoring of tolerance limit with respect to time and hence points towards an urgent need to change the World Health Organization's protocol for susceptibility identification in resistant P. argentipes.

  5. Metabolic expenditures of lunge feeding rorquals across scale: implications for the evolution of filter feeding and the limits to maximum body size.

    Directory of Open Access Journals (Sweden)

    Jean Potvin

    Full Text Available Bulk-filter feeding is an energetically efficient strategy for resource acquisition and assimilation, and facilitates the maintenance of extreme body size as exemplified by baleen whales (Mysticeti and multiple lineages of bony and cartilaginous fishes. Among mysticetes, rorqual whales (Balaenopteridae exhibit an intermittent ram filter feeding mode, lunge feeding, which requires the abandonment of body-streamlining in favor of a high-drag, mouth-open configuration aimed at engulfing a very large amount of prey-laden water. Particularly while lunge feeding on krill (the most widespread prey preference among rorquals, the effort required during engulfment involve short bouts of high-intensity muscle activity that demand high metabolic output. We used computational modeling together with morphological and kinematic data on humpback (Megaptera noveaangliae, fin (Balaenoptera physalus, blue (Balaenoptera musculus and minke (Balaenoptera acutorostrata whales to estimate engulfment power output in comparison with standard metrics of metabolic rate. The simulations reveal that engulfment metabolism increases across the full body size of the larger rorqual species to nearly 50 times the basal metabolic rate of terrestrial mammals of the same body mass. Moreover, they suggest that the metabolism of the largest body sizes runs with significant oxygen deficits during mouth opening, namely, 20% over maximum VO2 at the size of the largest blue whales, thus requiring significant contributions from anaerobic catabolism during a lunge and significant recovery after a lunge. Our analyses show that engulfment metabolism is also significantly lower for smaller adults, typically one-tenth to one-half VO2|max. These results not only point to a physiological limit on maximum body size in this lineage, but also have major implications for the ontogeny of extant rorquals as well as the evolutionary pathways used by ancestral toothed whales to transition from hunting

  6. Fenton oxidation to remediate PAHs in contaminated soils: A critical review of major limitations and counter-strategies.

    Science.gov (United States)

    Usman, M; Hanna, K; Haderlein, S

    2016-11-01

    Fenton oxidation constitutes a viable remediation strategy to remove polycyclic aromatic hydrocarbons (PAHs) in contaminated soils. This review is intended to illustrate major limitations associated with this process like acidification, PAH unavailability, and deterioration of soil quality along with associated factors, followed by a critical description of various developments to overcome these constraints. Considering the limitation that its optimal pH is around 3, traditional Fenton treatment could be costly, impractical in soil due to the high buffering capacity of soils and associated hazardous effects. Use of various chelating agents (organic or inorganic) allowed oxidation at circumneutral pH but factors like higher oxidant demand, cost and toxicity should be considered. Another alternative is the use of iron minerals that can catalyze Fenton-like oxidation over a wide range of pH, but mobility of these particles in soils (i.e. saturated and unsaturated zones) should be investigated prior to in-situ applications. The PAH-unavailability is the crucial limitation hindering their effective degradation. Research data is compiled describing various strategies to address this issue like the use of availability enhancement agents, extraction or thermal pretreatment. Last section of this review is devoted to describe the effects of various developments in Fenton treatment onto soil quality and native microbiota. Finally, research gaps are discussed to suggest future directions in context of applying Fenton oxidation to remediate contaminated soils. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Soil contamination. part 1. changes in the humidity of non saturated soils after reject in a limited space. part 2. movements of radioactive ions in non saturated soils after reject in a limited space

    International Nuclear Information System (INIS)

    Rancon, D.

    1969-01-01

    An important feature in radiological safety studies of sites is the knowledge of water movements in the unsaturated layer surmounting aquifer; this zone of aerated soil can be effective as a protection against aquifer contamination. Utilizing a neutron-moisture meter, a method was developed permitting to build graphically the hydric states of soil and the moistened volume evolution with time in the particular case of a limited feeding surface. It is also possible to measure moisture gradients, drying kinetics, the retention capacity of soil and the gravific water content achieved by a given water head. The initial hydric state has an effect only upon the infiltration rate and neither upon the moistened front position nor upon the volume of moistened soil; consequently, the storable water amount in soil can be calculated. When water feeding has been stopped, the volume of moistened soil increases to an equilibrium state restricted by the moistened front and all the other water movements occur exclusively inside this volume. Consequently in case of radioactive waste disposal, the ionic pollution will be confined inside a measurable volume, the moistened front being the maximum limits of this volume. Part 2. Following up the report on water movements in non-saturated s o i l s after reject on a limited space - CEA R 3635 (1) - the radioactive ions movements in these soils are studied in using an anion and a cation of reference: iodine 131 and strontium 85. The experimental method is founded on the simultaneous measurements of moisture and radioactivity fronts by means of a neutrons moisture meter and an specially conceived radioactivity probe. It has so been possible to measure: the relative velocities of moisture and radioactivity fronts; the contaminated soil volume inside the moistened oil volume; the concentration gradients; the contamination changes upon watering; the effect of chemical composition of water upon this ions movements and the effect of soil moisture

  8. Prey size and availability limits maximum size of rainbow trout in a large tailwater: insights from a drift-foraging bioenergetics model

    Science.gov (United States)

    Dodrill, Michael J.; Yackulic, Charles B.; Kennedy, Theodore A.; Haye, John W

    2016-01-01

    The cold and clear water conditions present below many large dams create ideal conditions for the development of economically important salmonid fisheries. Many of these tailwater fisheries have experienced declines in the abundance and condition of large trout species, yet the causes of these declines remain uncertain. Here, we develop, assess, and apply a drift-foraging bioenergetics model to identify the factors limiting rainbow trout (Oncorhynchus mykiss) growth in a large tailwater. We explored the relative importance of temperature, prey quantity, and prey size by constructing scenarios where these variables, both singly and in combination, were altered. Predicted growth matched empirical mass-at-age estimates, particularly for younger ages, demonstrating that the model accurately describes how current temperature and prey conditions interact to determine rainbow trout growth. Modeling scenarios that artificially inflated prey size and abundance demonstrate that rainbow trout growth is limited by the scarcity of large prey items and overall prey availability. For example, shifting 10% of the prey biomass to the 13 mm (large) length class, without increasing overall prey biomass, increased lifetime maximum mass of rainbow trout by 88%. Additionally, warmer temperatures resulted in lower predicted growth at current and lower levels of prey availability; however, growth was similar across all temperatures at higher levels of prey availability. Climate change will likely alter flow and temperature regimes in large rivers with corresponding changes to invertebrate prey resources used by fish. Broader application of drift-foraging bioenergetics models to build a mechanistic understanding of how changes to habitat conditions and prey resources affect growth of salmonids will benefit management of tailwater fisheries.

  9. Critical evaluation of the limit of transuranic contamination of low level waste

    International Nuclear Information System (INIS)

    Rodger, W.A.

    1976-01-01

    The suggested limit for transuranics of 10 nanocuries/gram as a break point at which wastes should go to a national repository is seriously questioned. It is shown that insofar as protection of water supplies is concerned, the key to the problem is $sup 90$Sr, not transuranics, and in any case, the limit should be based on a site-determined inventory, not on concentration. Concentration is only important as a protection for future stumblers who might dig into the waste. Calculations are presented to show that for this purpose the limit should be higher by several orders of magnitude. The 10 nanocurie/gram should be used as a definition of complete innocuousness. 4 refs

  10. Emergency and Continuous Exposure Limits for Selected Airborne Contaminants. Volume 1

    Science.gov (United States)

    1984-04-01

    fuels, corn remover, drawing inks, fuel-system deicer, glue, nail-polish remover, paint-brush cleaners, paint and varnish removers, and china ,• ~ ~film...and fire hazards of butanone and acetone. Ind. Bull. (N.Y. State Dept. Labor) 23:173-176. Societa Italiana di Medicina del Lavoro. 1975. Associazione...Italiana di Medicina del Lavoro 1975. Associazione Italiana - -degli Igienisti Industriali. Valori Limite Ponderati degli Inquinanti Chimici e

  11. Analysis of the Ability of United States and Russian Trace Contaminant Control Systems to Meet U.S. 180-Day and Russian 360-Day Spacecraft Maximum Allowable Concentrations

    Science.gov (United States)

    Perry, J. L.

    2016-01-01

    As the Space Station Freedom program transitioned to become the International Space Station (ISS), uncertainty existed concerning the performance capabilities for U.S.- and Russian-provided trace contaminant control (TCC) equipment. In preparation for the first dialogue between NASA and Russian Space Agency personnel in Moscow, Russia, in late April 1994, an engineering analysis was conducted to serve as a basis for discussing TCC equipment engineering assumptions as well as relevant assumptions on equipment offgassing and cabin air quality standards. The analysis presented was conducted as part of the efforts to integrate Russia into the ISS program via the early ISS Multilateral Medical Operations Panel's Air Quality Subgroup deliberations. This analysis, served as a basis for technical deliberations that established a framework for TCC system design and operations among the ISS program's international partners that has been instrumental in successfully managing the ISS common cabin environment.

  12. Evaluation of the Charm maximum residue limit β-lactam and tetracycline test for the detection of antibiotics in ewe and goat milk.

    Science.gov (United States)

    Beltrán, M C; Romero, T; Althaus, R L; Molina, M P

    2013-05-01

    The Charm maximum residue limit β-lactam and tetracycline test (Charm MRL BLTET; Charm Sciences Inc., Lawrence, MA) is an immunoreceptor assay utilizing Rapid One-Step Assay lateral flow technology that detects β-lactam or tetracycline drugs in raw commingled cow milk at or below European Union maximum residue levels (EU-MRL). The Charm MRL BLTET test procedure was recently modified (dilution in buffer and longer incubation) by the manufacturers to be used with raw ewe and goat milk. To assess the Charm MRL BLTET test for the detection of β-lactams and tetracyclines in milk of small ruminants, an evaluation study was performed at Instituto de Ciencia y Tecnologia Animal of Universitat Politècnica de València (Spain). The test specificity and detection capability (CCβ) were studied following Commission Decision 2002/657/EC. Specificity results obtained in this study were optimal for individual milk free of antimicrobials from ewes (99.2% for β-lactams and 100% for tetracyclines) and goats (97.9% for β-lactams and 100% for tetracyclines) along the entire lactation period regardless of whether the results were visually or instrumentally interpreted. Moreover, no positive results were obtained when a relatively high concentration of different substances belonging to antimicrobial families other than β-lactams and tetracyclines were present in ewe and goat milk. For both types of milk, the CCβ calculated was lower or equal to EU-MRL for amoxicillin (4 µg/kg), ampicillin (4 µg/kg), benzylpenicillin (≤ 2 µg/kg), dicloxacillin (30 µg/kg), oxacillin (30 µg/kg), cefacetrile (≤ 63 µg/kg), cefalonium (≤ 10 µg/kg), cefapirin (≤ 30 µg/kg), desacetylcefapirin (≤ 30 µg/kg), cefazolin (≤ 25 µg/kg), cefoperazone (≤ 25 µg/kg), cefquinome (20 µg/kg), ceftiofur (≤ 50 µg/kg), desfuroylceftiofur (≤ 50µg/kg), and cephalexin (≤ 50 µg/kg). However, this test could neither detect cloxacillin nor nafcillin at or below EU-MRL (CCβ >30 µg/kg). The

  13. 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)

  14. Limited internal radiation exposure associated with resettlements to a radiation-contaminated homeland after the Fukushima Daiichi nuclear disaster.

    Directory of Open Access Journals (Sweden)

    Masaharu Tsubokura

    Full Text Available Resettlement to their radiation-contaminated hometown could be an option for people displaced at the time of a nuclear disaster; however, little information is available on the safety implications of these resettlement programs. Kawauchi village, located 12-30 km southwest of the Fukushima Daiichi nuclear power plant, was one of the 11 municipalities where mandatory evacuation was ordered by the central government. This village was also the first municipality to organize the return of the villagers. To assess the validity of the Kawauchi villagers' resettlement program, the levels of internal Cesium (Cs exposures were comparatively measured in returnees, commuters, and non-returnees among the Kawauchi villagers using a whole body counter. Of 149 individuals, 5 villagers had traceable levels of Cs exposure; the median detected level was 333 Bq/body (range, 309-1050 Bq/kg, and 5.3 Bq/kg (range, 5.1-18.2 Bq/kg. Median annual effective doses of villagers with traceable Cs were 1.1 x 10(-2 mSv/y (range, 1.0 x 10(-2-4.1 x 10(-2 mSv/y. Although returnees had higher chances of consuming locally produced vegetables, Cochran-Mantel-Haenszel test showed that their level of internal radiation exposure was not significantly higher than that in the other 2 groups (p=0.643. The present findings in Kawauchi village imply that it is possible to maintain internal radiation exposure at very low levels even in a highly radiation-contaminated region at the time of a nuclear disaster. Moreover, the risks for internal radiation exposure could be limited with a strict food control intervention after resettlement to the radiation-contaminated village. It is crucial to establish an adequate number of radio-contaminated testing sites within the village, to provide immediate test result feedback to the villagers, and to provide education regarding the importance of re-testing in reducing the risk of high internal radiation exposure.

  15. The role of dose limitation and optimization in intervention. Approaches to the remediation of contaminated sites in Germany

    International Nuclear Information System (INIS)

    Goldammer, W.; Helming, M.; Kuehnel, G.; Landfermann, H.-H.

    2000-01-01

    The clean-up of contaminated sites requires appropriate and efficient methodologies for the decision-making about priorities and extent of remedial measures, aiming at the two, usually conflicting, goals to protect people and the environment and to save money and other resources. Finding the cost-effective balance between these two primary objectives often is complicated by several factors. Sensible decision-making in this situation requires the use of appropriate methodologies and tools which assist in identifying and implementing the optimal solution. The paper discusses an approach developed in Germany to achieve environmentally sound and cost-effective solutions. A basic requirement within the German approach is the limitation of individual doses in order to limit inequity between people exposed. An Action Level of 1 mSv per annum is used in this sense for the identification of sites that require farther investigation and potentially remediation. On the basis of this individual dose related criterion secondary reference levels for directly measurable quantities such as activity concentrations have been derived, facilitating the practical application of the Action Level Concept. Decisions on remedial action, in particular for complex sites, are based on justification and optimization analyses. These take into consideration a variety of different contaminants and risks to humans and the environment arising on various exposure pathways. The optimization analyses, carried-out to identify optimal remediation options, address radiological risks as well as short and long term costs within a cost-benefit analysis framework. Other relevant factors of influence, e.g. chemical risks or ecological damage, are incorporated as well. Comprehensive methodologies utilizing probabilistic methods have been developed to assess site conditions and possible remediation options on this basis. The approaches developed are applied within the German uranium mine rehabilitation program

  16. The role of dose limitation and optimization in intervention. Approaches to the remediation of contaminated sites in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Goldammer, W. [Brenk Systemplanung GmbH, Aachen (Germany); Helming, M.; Kuehnel, G.; Landfermann, H.-H. [Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, Bonn (Germany)

    2000-05-01

    The clean-up of contaminated sites requires appropriate and efficient methodologies for the decision-making about priorities and extent of remedial measures, aiming at the two, usually conflicting, goals to protect people and the environment and to save money and other resources. Finding the cost-effective balance between these two primary objectives often is complicated by several factors. Sensible decision-making in this situation requires the use of appropriate methodologies and tools which assist in identifying and implementing the optimal solution. The paper discusses an approach developed in Germany to achieve environmentally sound and cost-effective solutions. A basic requirement within the German approach is the limitation of individual doses in order to limit inequity between people exposed. An Action Level of 1 mSv per annum is used in this sense for the identification of sites that require farther investigation and potentially remediation. On the basis of this individual dose related criterion secondary reference levels for directly measurable quantities such as activity concentrations have been derived, facilitating the practical application of the Action Level Concept. Decisions on remedial action, in particular for complex sites, are based on justification and optimization analyses. These take into consideration a variety of different contaminants and risks to humans and the environment arising on various exposure pathways. The optimization analyses, carried-out to identify optimal remediation options, address radiological risks as well as short and long term costs within a cost-benefit analysis framework. Other relevant factors of influence, e.g. chemical risks or ecological damage, are incorporated as well. Comprehensive methodologies utilizing probabilistic methods have been developed to assess site conditions and possible remediation options on this basis. The approaches developed are applied within the German uranium mine rehabilitation program

  17. Drinking Water Maximum Contaminant Levels (MCLs)

    Data.gov (United States)

    U.S. Environmental Protection Agency — National Primary Drinking Water Regulations (NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards...

  18. Treponema pallidum 3-Phosphoglycerate Mutase Is a Heat-Labile Enzyme That May Limit the Maximum Growth Temperature for the Spirochete

    Science.gov (United States)

    Benoit, Stéphane; Posey, James E.; Chenoweth, Matthew R.; Gherardini, Frank C.

    2001-01-01

    In the causative agent of syphilis, Treponema pallidum, the gene encoding 3-phosphoglycerate mutase, gpm, is part of a six-gene operon (tro operon) that is regulated by the Mn-dependent repressor TroR. Since substrate-level phosphorylation via the Embden-Meyerhof pathway is the principal way to generate ATP in T. pallidum and Gpm is a key enzyme in this pathway, Mn could exert a regulatory effect on central metabolism in this bacterium. To study this, T. pallidum gpm was cloned, Gpm was purified from Escherichia coli, and antiserum against the recombinant protein was raised. Immunoblots indicated that Gpm was expressed in freshly extracted infective T. pallidum. Enzyme assays indicated that Gpm did not require Mn2+ while 2,3-diphosphoglycerate (DPG) was required for maximum activity. Consistent with these observations, Mn did not copurify with Gpm. The purified Gpm was stable for more than 4 h at 25°C, retained only 50% activity after incubation for 20 min at 34°C or 10 min at 37°C, and was completely inactive after 10 min at 42°C. The temperature effect was attenuated when 1 mM DPG was added to the assay mixture. The recombinant Gpm from pSLB2 complemented E. coli strain PL225 (gpm) and restored growth on minimal glucose medium in a temperature-dependent manner. Increasing the temperature of cultures of E. coli PL225 harboring pSLB2 from 34 to 42°C resulted in a 7- to 11-h period in which no growth occurred (compared to wild-type E. coli). These data suggest that biochemical properties of Gpm could be one contributing factor to the heat sensitivity of T. pallidum. PMID:11466272

  19. Method of estimating maximum VOC concentration in void volume of vented waste drums using limited sampling data: Application in transuranic waste drums

    International Nuclear Information System (INIS)

    Liekhus, K.J.; Connolly, M.J.

    1995-01-01

    A test program has been conducted at the Idaho National Engineering Laboratory to demonstrate that the concentration of volatile organic compounds (VOCs) within the innermost layer of confinement in a vented waste drum can be estimated using a model incorporating diffusion and permeation transport principles as well as limited waste drum sampling data. The model consists of a series of material balance equations describing steady-state VOC transport from each distinct void volume in the drum. The primary model input is the measured drum headspace VOC concentration. Model parameters are determined or estimated based on available process knowledge. The model effectiveness in estimating VOC concentration in the headspace of the innermost layer of confinement was examined for vented waste drums containing different waste types and configurations. This paper summarizes the experimental measurements and model predictions in vented transuranic waste drums containing solidified sludges and solid waste

  20. Experimental studies to validate model calculations and maximum solubility limits for Plutonium and Americium; Experimentelle Arbeiten zur Absicherung von Modellrechnungen und Maximalkonzentrationen fuer Plutonium und Americium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2017-02-16

    This report focuses on studies of KIT-INE to derive a significantly improved description of the chemical behaviour of Americium and Plutonium in saline NaCl, MgCl{sub 2} and CaCl{sub 2} brine systems. The studies are based on new experimental data and aim at deriving reliable Am and Pu solubility limits for the investigated systems as well as deriving comprehensive thermodynamic model descriptions. Both aspects are of high relevance in the context of potential source term estimations for Americium and Plutonium in aqueous brine systems and related scenarios. Americium and Plutonium are long-lived alpha emitting radionuclides which due to their high radiotoxicity need to be accounted for in a reliable and traceable way. The hydrolysis of trivalent actinides and the effect of highly alkaline pH conditions on the solubility of trivalent actinides in calcium chloride rich brine solutions were investigated and a thermodynamic model derived. The solubility of Plutonium in saline brine systems was studied under reducing and non-reducing conditions and is described within a new thermodynamic model. The influence of dissolved carbonate on Americium and Plutonium solubility in MgCl{sub 2} solutions was investigated and quantitative information on Am and Pu solubility limits in these systems derived. Thermodynamic constants and model parameter derived in this work are implemented in the Thermodynamic Reference Database THEREDA owned by BfS. According to the quality assurance approach in THEREDA, is was necessary to publish parts of this work in peer-reviewed scientific journals. The publications are focused on solubility experiments, spectroscopy of aquatic and solid species and thermodynamic data. (Neck et al., Pure Appl. Chem., Vol. 81, (2009), pp. 1555-1568., Altmaier et al., Radiochimica Acta, 97, (2009), pp. 187-192., Altmaier et al., Actinide Research Quarterly, No 2., (2011), pp. 29-32.).

  1. Influência do oeríodo de cultivo de Panicum maximum (cultivar Tanzânia na fitorremediação de solo contaminado com picloram Influence of Panicum maximum cultivation period on phytoremediation of soil contaminated with picloram

    Directory of Open Access Journals (Sweden)

    M.L. Carmo

    2008-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a influência do tempo de cultivo de Panicum maximum (cultivar Tanzânia sobre a fitorremediação de solo contaminado com picloram. O experimento foi conduzido em casa de vegetação no período de setembro de 2006 a fevereiro de 2007. Os fatores foram compostos pela combinação entre quatro períodos de cultivo da espécie vegetal Panicum maximum (cultivar Tanzânia (0, 60, 80 e 100 dias e três doses do picloram (0, 80 e 160 g ha-1, totalizando 12 tratamentos. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 4 x 3, com quatro repetições. Como substrato utilizaram-se amostras de solo classificado como Latossolo Vermelho eutroférrico. Após o tempo estabelecido de atuação da espécie fitorremediadora, efetuou-se a semeadura das espécies bioindicadoras da presença do picloram: tomate e soja. As espécies bioindicadoras demonstraram alta sensibilidade à presença do picloram no solo, sendo inviável o cultivo dessas culturas em áreas contaminadas com esse herbicida sem a execução de algum procedimento remediador. O cultivo prévio de Tanzânia por 60 dias garantiu crescimento inicial satisfatório das plantas de soja e tomate quando a contaminação inicial não foi maior que 80 g ha-1 de picloram. Acima desse valor, a fitorremediação ocorrida proporcionou menor crescimento das plantas de soja e tomate, sendo necessário maior tempo de descontaminação.The objective of this study was to evaluate the influence of cultivation time of Panicum maximum (cv. Tanzania on phyto-remediation of soil contaminated with picloram. The experiment was carried out under greenhouse conditions from September 2006 to February 2007, using euthroferric Red Latosol samples as substrate for plant growth. The experiment was arranged in a completely randomized design, with four replicates, with treatments in a 4 x 3 factorial scheme. The treatments comprised twelve combinations of

  2. A STUDY OF DISSOLUTION RATE-LIMITED BIOREMEDIATION OF SOILS CONTAMINATED BY RESIDUAL HYDROCARBONS. (R825549C039)

    Science.gov (United States)

    The widespread release of organic chemicals in the environment frequently leads to ground-water contamination with non-aqueous phase liquids (NAPLs) because many of these organic chemicals are barely soluble in water. Understanding the mechanisms of transport and biotic transf...

  3. Limit values used in the European Union for managing excavated land and contaminated soils; Valores limite en la Union Europea para la gestion de tierras excavadas y suelos contaminados

    Energy Technology Data Exchange (ETDEWEB)

    Soto Diaz, E.; Rodriguez Abad, R.

    2014-07-01

    In this paper, which is a summary of the minor thesis of the same title, a qualitative comparison is made between mean limit values applied in different member countries of the European Union (EU) for the proper management of excavated lands and contaminated soils. This management can be carried out as a byproduct through its reuse, recycling or previous treatment, or through its consideration as a waste and its subsequent admission to a particular type of landfill. Three types of comparisons of UE limit values are done in this paper: between those established in six member countries for the use of excavated lands as a byproduct, between those existing in 15 European countries for contaminated soils, and finally between those required in 12 EU countries for their land filling. (Author)

  4. A comparative study on the forming limit diagram prediction between Marciniak-Kuczynski model and modified maximum force criterion by using the evolving non-associated Hill48 plasticity model

    Science.gov (United States)

    Shen, Fuhui; Lian, Junhe; Münstermann, Sebastian

    2018-05-01

    Experimental and numerical investigations on the forming limit diagram (FLD) of a ferritic stainless steel were performed in this study. The FLD of this material was obtained by Nakajima tests. Both the Marciniak-Kuczynski (MK) model and the modified maximum force criterion (MMFC) were used for the theoretical prediction of the FLD. From the results of uniaxial tensile tests along different loading directions with respect to the rolling direction, strong anisotropic plastic behaviour was observed in the investigated steel. A recently proposed anisotropic evolving non-associated Hill48 (enHill48) plasticity model, which was developed from the conventional Hill48 model based on the non-associated flow rule with evolving anisotropic parameters, was adopted to describe the anisotropic hardening behaviour of the investigated material. In the previous study, the model was coupled with the MMFC for FLD prediction. In the current study, the enHill48 was further coupled with the MK model. By comparing the predicted forming limit curves with the experimental results, the influences of anisotropy in terms of flow rule and evolving features on the forming limit prediction were revealed and analysed. In addition, the forming limit predictive performances of the MK and the MMFC models in conjunction with the enHill48 plasticity model were compared and evaluated.

  5. A Limited Microbial Consortium Is Responsible for Extended Bioreduction of Uranium in a Contaminated Aquifer ▿†

    Science.gov (United States)

    Gihring, Thomas M.; Zhang, Gengxin; Brandt, Craig C.; Brooks, Scott C.; Campbell, James H.; Carroll, Susan; Criddle, Craig S.; Green, Stefan J.; Jardine, Phil; Kostka, Joel E.; Lowe, Kenneth; Mehlhorn, Tonia L.; Overholt, Will; Watson, David B.; Yang, Zamin; Wu, Wei-Min; Schadt, Christopher W.

    2011-01-01

    Subsurface amendments of slow-release substrates (e.g., emulsified vegetable oil [EVO]) are thought to be a pragmatic alternative to using short-lived, labile substrates for sustained uranium bioimmobilization within contaminated groundwater systems. Spatial and temporal dynamics of subsurface microbial communities during EVO amendment are unknown and likely differ significantly from those of populations stimulated by soluble substrates, such as ethanol and acetate. In this study, a one-time EVO injection resulted in decreased groundwater U concentrations that remained below initial levels for approximately 4 months. Pyrosequencing and quantitative PCR of 16S rRNA from monitoring well samples revealed a rapid decline in groundwater bacterial community richness and diversity after EVO injection, concurrent with increased 16S rRNA copy levels, indicating the selection of a narrow group of taxa rather than a broad community stimulation. Members of the Firmicutes family Veillonellaceae dominated after injection and most likely catalyzed the initial oil decomposition. Sulfate-reducing bacteria from the genus Desulforegula, known for long-chain fatty acid oxidation to acetate, also dominated after EVO amendment. Acetate and H2 production during EVO degradation appeared to stimulate NO3−, Fe(III), U(VI), and SO42− reduction by members of the Comamonadaceae, Geobacteriaceae, and Desulfobacterales. Methanogenic archaea flourished late to comprise over 25% of the total microbial community. Bacterial diversity rebounded after 9 months, although community compositions remained distinct from the preamendment conditions. These results demonstrated that a one-time EVO amendment served as an effective electron donor source for in situ U(VI) bioreduction and that subsurface EVO degradation and metal reduction were likely mediated by successive identifiable guilds of organisms. PMID:21764967

  6. 210Pb-derived ages for the reconstruction of terrestrial contaminant history into the Mexican Pacific coast: Potential and limitations

    International Nuclear Information System (INIS)

    Ruiz-Fernandez, A.C.; Hillaire-Marcel, C.

    2009-01-01

    210 Pb is widely used for dating recent sediments in the aquatic environment; however, our experiences working in shallow coastal environments in the Pacific coast of Mexico have demonstrated that the potential of 210 Pb for reliable historical reconstructions might be limited by the low 210 Pb atmospheric fallout, sediment mixing, abundance of coarse sediments and the lack of 137 Cs signal for 210 Pb corroboration. This work discusses the difficulties in obtaining adequate sedimentary records for geochronological reconstruction in such active and complex settings, including examples of 210 Pb geochronologies based on sediment profiles collected in two contrasting areas coastal areas (mudflats associated to coastal lagoons of Sinaloa State and the continental shelf of the Gulf of Tehuantepec), in which geochemical data was used to support the temporal frame established and the changes in sediment supply recorded in the sediment cores which were related to the development of land-based activities during the last century.

  7. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

  8. Soil contamination. part 1. changes in the humidity of non saturated soils after reject in a limited space. part 2. movements of radioactive ions in non saturated soils after reject in a limited space; Contamination des sols (1. partie). Evolution de l'humidite dans les sols non satures apres rejets sur une surface limitee. (2. partie). Comportement des ions radioactifs dans les sols non satures apres rejets d'eau sur une surface limitee

    Energy Technology Data Exchange (ETDEWEB)

    Rancon, D [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1972-07-01

    An important feature in radiological safety studies of sites is the knowledge of water movements in the unsaturated layer surmounting aquifer; this zone of aerated soil can be effective as a protection against aquifer contamination. Utilizing a neutron-moisture meter, a method was developed permitting to build graphically the hydric states of soil and the moistened volume evolution with time in the particular case of a limited feeding surface. It is also possible to measure moisture gradients, drying kinetics, the retention capacity of soil and the gravific water content achieved by a given water head. The initial hydric state has an effect only upon the infiltration rate and neither upon the moistened front position nor upon the volume of moistened soil; consequently, the storable water amount in soil can be calculated. When water feeding has been stopped, the volume of moistened soil increases to an equilibrium state restricted by the moistened front and all the other water movements occur exclusively inside this volume. Consequently in case of radioactive waste disposal, the ionic pollution will be confined inside a measurable volume, the moistened front being the maximum limits of this volume. Part 2. Following up the report on water movements in non-saturated s o i l s after reject on a limited space - CEA R 3635 (1) - the radioactive ions movements in these soils are studied in using an anion and a cation of reference: iodine 131 and strontium 85. The experimental method is founded on the simultaneous measurements of moisture and radioactivity fronts by means of a neutrons moisture meter and an specially conceived radioactivity probe. It has so been possible to measure: the relative velocities of moisture and radioactivity fronts; the contaminated soil volume inside the moistened oil volume; the concentration gradients; the contamination changes upon watering; the effect of chemical composition of water upon this ions movements and the effect of soil moisture

  9. Nitric Oxide and Oxygen Air-Contamination Effects on Extinction Limits of Non-Premixed Hydrocarbon-Air Flames for a HIFiRE Scramjet

    Science.gov (United States)

    Pellett, Gerald L.; Dawson, Lucy C.; Vaden, Sarah N.; Wilson, Lloyd G.

    2009-01-01

    Unique nitric oxide (NO) and oxygen air-contamination effects on the extinction Flame Strength (FS) of non-premixed hydrocarbon (HC) vs. air flames are characterized for 7 gaseous HCs, using a new idealized 9.3 mm straight-tube Opposed Jet Burner (OJB) at 1 atm. FS represents a laminar strain-induced extinction limit based on cross-section-average air jet velocity, Uair, that sustains combustion of a counter jet of gaseous fuel just before extinction. Besides ethane, propane, butane, and propylene, the HCs include ethylene, methane, and a 64 mole-% ethylene / 36 % methane mixture, the writer s previously recommended gaseous surrogate fuel for HIFiRE scramjet tests. The HC vs. clean air part of the work is an extension of a May 2008 JANNAF paper that characterized surrogates for the HIFiRE project that should mimic the flameholding of reformed (thermally- or catalytically-cracked) endothermic JP-like fuels. The new FS data for 7 HCs vs. clean air are thus consolidated with the previously validated data, normalized to absolute (local) axial-input strain rates, and co-plotted on a dual kinetically dominated reactivity scale. Excellent agreement with the prior data is obtained for all 7 fuels. Detailed comparisons are also made with recently published (Univ. Va) numerical results for ethylene extinction. A 2009-revised ethylene kinetic model (Univ. Southern Cal) led to predicted limits within approx. 5 % (compared to 45 %, earlier) of this writer s 2008 (and present) ethylene FSs, and also with recent independent data (Univ. Va) obtained on a new OJB system. These +/- 5 % agreements, and a hoped-for "near-identically-performing" reduced kinetics model, would greatly enhance the capability for accurate numerical simulations of surrogate HC flameholding in scramjets. The measured air-contamination effects on normalized FS extinction limits are projected to assess ongoing Arc-Heater-induced "facility test effects" of NO production (e.g., 3 mole-%) and resultant oxygen

  10. Urban atmospheric contamination

    International Nuclear Information System (INIS)

    Baldasano Jose, M.

    1997-01-01

    The problems of contamination are not only limited to this century, pale pathology evidences of the effects of the contamination of the air exist in interiors in the health of the old ones; the article mention the elements that configure the problem of the atmospheric contamination, atmospheric pollutants and emission sources, orography condition and effects induced by the urbanization process

  11. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  12. Maximum Quantum Entropy Method

    OpenAIRE

    Sim, Jae-Hoon; Han, Myung Joon

    2018-01-01

    Maximum entropy method for analytic continuation is extended by introducing quantum relative entropy. This new method is formulated in terms of matrix-valued functions and therefore invariant under arbitrary unitary transformation of input matrix. As a result, the continuation of off-diagonal elements becomes straightforward. Without introducing any further ambiguity, the Bayesian probabilistic interpretation is maintained just as in the conventional maximum entropy method. The applications o...

  13. Maximum power demand cost

    International Nuclear Information System (INIS)

    Biondi, L.

    1998-01-01

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

  14. Maximum likely scale estimation

    DEFF Research Database (Denmark)

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

    2005-01-01

    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  15. Robust Maximum Association Estimators

    NARCIS (Netherlands)

    A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

    2017-01-01

    textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

  16. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  17. Maximum permissible voltage of YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: zhiyong.hong@sjtu.edu.cn [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)

    2014-06-15

    Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

  18. Atmospheric contamination

    International Nuclear Information System (INIS)

    Gruetter, Juerg

    1997-01-01

    It is about the levels of contamination in center America, the population's perception on the problem, effects of the atmospheric contamination, effects in the environment, causes of the atmospheric contamination, possibilities to reduce the atmospheric contamination and list of Roeco Swisscontac in atmospheric contamination

  19. Remarks on the maximum luminosity

    Science.gov (United States)

    Cardoso, Vitor; Ikeda, Taishi; Moore, Christopher J.; Yoo, Chul-Moon

    2018-04-01

    The quest for fundamental limitations on physical processes is old and venerable. Here, we investigate the maximum possible power, or luminosity, that any event can produce. We show, via full nonlinear simulations of Einstein's equations, that there exist initial conditions which give rise to arbitrarily large luminosities. However, the requirement that there is no past horizon in the spacetime seems to limit the luminosity to below the Planck value, LP=c5/G . Numerical relativity simulations of critical collapse yield the largest luminosities observed to date, ≈ 0.2 LP . We also present an analytic solution to the Einstein equations which seems to give an unboundedly large luminosity; this will guide future numerical efforts to investigate super-Planckian luminosities.

  20. Maximum entropy methods

    International Nuclear Information System (INIS)

    Ponman, T.J.

    1984-01-01

    For some years now two different expressions have been in use for maximum entropy image restoration and there has been some controversy over which one is appropriate for a given problem. Here two further entropies are presented and it is argued that there is no single correct algorithm. The properties of the four different methods are compared using simple 1D simulations with a view to showing how they can be used together to gain as much information as possible about the original object. (orig.)

  1. The last glacial maximum

    Science.gov (United States)

    Clark, P.U.; Dyke, A.S.; Shakun, J.D.; Carlson, A.E.; Clark, J.; Wohlfarth, B.; Mitrovica, J.X.; Hostetler, S.W.; McCabe, A.M.

    2009-01-01

    We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Nearly all ice sheets were at their LGM positions from 26.5 ka to 19 to 20 ka, corresponding to minima in these forcings. The onset of Northern Hemisphere deglaciation 19 to 20 ka was induced by an increase in northern summer insolation, providing the source for an abrupt rise in sea level. The onset of deglaciation of the West Antarctic Ice Sheet occurred between 14 and 15 ka, consistent with evidence that this was the primary source for an abrupt rise in sea level ???14.5 ka.

  2. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  3. Probable maximum flood control

    International Nuclear Information System (INIS)

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility

  4. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1988-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. We review the need for such methods in data analysis and show, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. We conclude with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  5. Solar maximum observatory

    International Nuclear Information System (INIS)

    Rust, D.M.

    1984-01-01

    The successful retrieval and repair of the Solar Maximum Mission (SMM) satellite by Shuttle astronauts in April 1984 permitted continuance of solar flare observations that began in 1980. The SMM carries a soft X ray polychromator, gamma ray, UV and hard X ray imaging spectrometers, a coronagraph/polarimeter and particle counters. The data gathered thus far indicated that electrical potentials of 25 MeV develop in flares within 2 sec of onset. X ray data show that flares are composed of compressed magnetic loops that have come too close together. Other data have been taken on mass ejection, impacts of electron beams and conduction fronts with the chromosphere and changes in the solar radiant flux due to sunspots. 13 references

  6. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1989-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. The author reviews the need for such methods in data analysis and shows, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. He concludes with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  7. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    MAF outperforms the functional PCA in concentrating the interesting' spectra/shape variation in one end of the eigenvalue spectrum and allows for easier interpretation of effects. Conclusions. Functional MAF analysis is a useful methods for extracting low dimensional models of temporally or spatially......Purpose. We aim at data where samples of an underlying function are observed in a spatial or temporal layout. Examples of underlying functions are reflectance spectra and biological shapes. We apply functional models based on smoothing splines and generalize the functional PCA in......\\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  8. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

    2015-01-01

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  9. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  10. correlation between maximum dry density and cohesion

    African Journals Online (AJOL)

    HOD

    represents maximum dry density, signifies plastic limit and is liquid limit. Researchers [6, 7] estimate compaction parameters. Aside from the correlation existing between compaction parameters and other physical quantities there are some other correlations that have been investigated by other researchers. The well-known.

  11. 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

  12. 40 CFR 141.66 - Maximum contaminant levels for radionuclides.

    Science.gov (United States)

    2010-07-01

    ... beta particle and photon radioactivity from man-made radionuclides in drinking water must not produce.../year). (2) Except for the radionuclides listed in table A, the concentration of man-made radionuclides... may make this technology too complex for small surface water systems. e Removal efficiencies can vary...

  13. Solar maximum mission

    International Nuclear Information System (INIS)

    Ryan, J.

    1981-01-01

    By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

  14. Maximum allowable load on wheeled mobile manipulators

    International Nuclear Information System (INIS)

    Habibnejad Korayem, M.; Ghariblu, H.

    2003-01-01

    This paper develops a computational technique for finding the maximum allowable load of mobile manipulator during a given trajectory. The maximum allowable loads which can be achieved by a mobile manipulator during a given trajectory are limited by the number of factors; probably the dynamic properties of mobile base and mounted manipulator, their actuator limitations and additional constraints applied to resolving the redundancy are the most important factors. To resolve extra D.O.F introduced by the base mobility, additional constraint functions are proposed directly in the task space of mobile manipulator. Finally, in two numerical examples involving a two-link planar manipulator mounted on a differentially driven mobile base, application of the method to determining maximum allowable load is verified. The simulation results demonstrates the maximum allowable load on a desired trajectory has not a unique value and directly depends on the additional constraint functions which applies to resolve the motion redundancy

  15. 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

  16. Maximum Credible Incidents

    CERN Document Server

    Strait, J

    2009-01-01

    Following the incident in sector 34, considerable effort has been made to improve the systems for detecting similar faults and to improve the safety systems to limit the damage if a similar incident should occur. Nevertheless, even after the consolidation and repairs are completed, other faults may still occur in the superconducting magnet systems, which could result in damage to the LHC. Such faults include both direct failures of a particular component or system, or an incorrect response to a “normal” upset condition, for example a quench. I will review a range of faults which could be reasonably expected to occur in the superconducting magnet systems, and which could result in substantial damage and down-time to the LHC. I will evaluate the probability and the consequences of such faults, and suggest what mitigations, if any, are possible to protect against each.

  17. Dosskin code for radiological evaluation of skin radioactive contaminations

    International Nuclear Information System (INIS)

    Cornejo D, N.

    1996-01-01

    The conceptual procedure and computational features of the DOSSKIN code are shown. This code calculates, in a very interactive way, skin equivalent doses and radiological risk related to skin radioactive contaminations. The evaluation takes into account the contributions of contaminant daughter nuclides and backscattering of beta particles in any skin cover. DOSSKIN also allows to estimate the maximum time needed to decontaminate the affected zone, using, as input quantity, the limit value of skin equivalent dose considered by users. The comparison of the results obtained by the DOSSKIN code with those reported by different authors are showed. The differences of results are less than 30%. (authors). 4 refs., 3 fig., 1 tab

  18. A comparative study of transfer factors of water, iodine and strontium on rye-grass and clover. Development of a model of evaluation of the limits of foliar contamination by wet deposit

    International Nuclear Information System (INIS)

    Angeletti, Livio; Levi, Emilio.

    1977-07-01

    Transfer factors of water, iodine ( 131 I) and strontium ( 85 Sr) on above-ground parts of rye-grass and clover were determined as a function of aspersion intensities. An analysis of the results showed the effect of aspersion intensities, nature of the chemical element and plant species on the values of transfer factors of iodine and strontium. It also made it possible to propose a simple method of evaluation of contamination limits of the aerial parts of plants by wet deposit, based on transfer values of water on plants only [fr

  19. HOME Rent Limits

    Data.gov (United States)

    Department of Housing and Urban Development — In accordance with 24 CFR Part 92.252, HUD provides maximum HOME rent limits. The maximum HOME rents are the lesser of: The fair market rent for existing housing for...

  20. Maximum likelihood estimation for integrated diffusion processes

    DEFF Research Database (Denmark)

    Baltazar-Larios, Fernando; Sørensen, Michael

    We propose a method for obtaining maximum likelihood estimates of parameters in diffusion models when the data is a discrete time sample of the integral of the process, while no direct observations of the process itself are available. The data are, moreover, assumed to be contaminated...... EM-algorithm to obtain maximum likelihood estimates of the parameters in the diffusion model. As part of the algorithm, we use a recent simple method for approximate simulation of diffusion bridges. In simulation studies for the Ornstein-Uhlenbeck process and the CIR process the proposed method works...... by measurement errors. Integrated volatility is an example of this type of observations. Another example is ice-core data on oxygen isotopes used to investigate paleo-temperatures. The data can be viewed as incomplete observations of a model with a tractable likelihood function. Therefore we propose a simulated...

  1. 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.

  2. 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)

  3. Maximum neutron flux in thermal reactors

    International Nuclear Information System (INIS)

    Strugar, P.V.

    1968-12-01

    Direct approach to the problem is to calculate spatial distribution of fuel concentration if the reactor core directly using the condition of maximum neutron flux and comply with thermal limitations. This paper proved that the problem can be solved by applying the variational calculus, i.e. by using the maximum principle of Pontryagin. Mathematical model of reactor core is based on the two-group neutron diffusion theory with some simplifications which make it appropriate from maximum principle point of view. Here applied theory of maximum principle are suitable for application. The solution of optimum distribution of fuel concentration in the reactor core is obtained in explicit analytical form. The reactor critical dimensions are roots of a system of nonlinear equations and verification of optimum conditions can be done only for specific examples

  4. Maximum gravitational redshift of white dwarfs

    International Nuclear Information System (INIS)

    Shapiro, S.L.; Teukolsky, S.A.

    1976-01-01

    The stability of uniformly rotating, cold white dwarfs is examined in the framework of the Parametrized Post-Newtonian (PPN) formalism of Will and Nordtvedt. The maximum central density and gravitational redshift of a white dwarf are determined as functions of five of the nine PPN parameters (γ, β, zeta 2 , zeta 3 , and zeta 4 ), the total angular momentum J, and the composition of the star. General relativity predicts that the maximum redshifts is 571 km s -1 for nonrotating carbon and helium dwarfs, but is lower for stars composed of heavier nuclei. Uniform rotation can increase the maximum redshift to 647 km s -1 for carbon stars (the neutronization limit) and to 893 km s -1 for helium stars (the uniform rotation limit). The redshift distribution of a larger sample of white dwarfs may help determine the composition of their cores

  5. 77 FR 37554 - Calculation of Maximum Obligation Limitation

    Science.gov (United States)

    2012-06-22

    ... definition of a financial company under section 201 of the Dodd- Frank Act. \\4\\ Section 203(b) of the Dodd... definition of a financial company under section 201. \\5\\ 12 U.S.C. 1823(c)(4). \\6\\ Section 201(a)(11) of the... is in default or in danger of default and that it meets the definition of financial company under...

  6. 76 FR 72645 - Calculation of Maximum Obligation Limitation

    Science.gov (United States)

    2011-11-25

    ..., inter alia, its powers and duties to: (1) Succeed to all rights, titles, powers and privileges of the... issued on or after January 1, 1999. The Agencies have sought to present the proposed rule in a simple and...

  7. 34 CFR 682.506 - Limitations on maximum loan amounts.

    Science.gov (United States)

    2010-07-01

    ... loan is intended less— (i) The student's estimated financial assistance; and (ii) The student's.... (b) The Secretary does not guarantee a Federal Consolidation loan in an amount greater than that required to discharge loans eligible for consolidation under § 682.100(a)(4). (Authority: 20 U.S.C. 1075...

  8. 5 CFR 582.402 - Maximum garnishment limitations.

    Science.gov (United States)

    2010-01-01

    ... earnings that may be garnished for a Federal, State or local tax obligation or in compliance with an order... alimony, including any amounts withheld to offset administrative costs as provided for in § 582.305(k... of an employee-obligor's aggregate disposable earnings for any workweek in compliance with legal...

  9. Maximum values and classifications of radionuclides

    International Nuclear Information System (INIS)

    1993-01-01

    The primary means of controlling the use of radiation are safety license procedure and the monitoring of radiation exposure and working conditions at places of radiation use. In Section 17 of the Finnish Radiation Act (592/91) certain operations are exempted from the safety license. The exemption limits for the licensing of radioactive materials, the radiotoxicity classification of radionuclides related to such exemption limits, the annual limits on intake of radionuclides to be followed when monitoring internal radiation dose, as well as concentration limits in the breathing air are specified in the guide. Also the surface contamination limits which must be followed when monitoring working conditions at places of radiation use are presented. (4 refs., 6 tabs.)

  10. NCRP soil contamination task group

    International Nuclear Information System (INIS)

    Jacobs, D.G.

    1987-01-01

    The National Council of Radiation Protection and Measurements (NCRP) has recently established a Task Group on Soil Contamination to describe and evaluate the migration pathways and modes of radiation exposure that can potentially arise due to radioactive contamination of soil. The purpose of this paper is to describe the scientific principles for evaluation of soil contamination which can be used as a basis for derivation of soil contamination limits for specific situations. This paper describes scenarios that can lead to soil contamination, important characteristics of soil contamination, the subsequent migration pathways and exposure modes, and the application of principles in the report in deriving soil contamination limits. The migration pathways and exposure modes discussed in this paper include: direct radiation exposure; and exhalation of gases

  11. A Novel Method for Remote Depth Estimation of Buried Radioactive Contamination.

    Science.gov (United States)

    Ukaegbu, Ikechukwu Kevin; Gamage, Kelum A A

    2018-02-08

    Existing remote radioactive contamination depth estimation methods for buried radioactive wastes are either limited to less than 2 cm or are based on empirical models that require foreknowledge of the maximum penetrable depth of the contamination. These severely limits their usefulness in some real life subsurface contamination scenarios. Therefore, this work presents a novel remote depth estimation method that is based on an approximate three-dimensional linear attenuation model that exploits the benefits of using multiple measurements obtained from the surface of the material in which the contamination is buried using a radiation detector. Simulation results showed that the proposed method is able to detect the depth of caesium-137 and cobalt-60 contamination buried up to 40 cm in both sand and concrete. Furthermore, results from experiments show that the method is able to detect the depth of caesium-137 contamination buried up to 12 cm in sand. The lower maximum depth recorded in the experiment is due to limitations in the detector and the low activity of the caesium-137 source used. Nevertheless, both results demonstrate the superior capability of the proposed method compared to existing methods.

  12. Credal Networks under Maximum Entropy

    OpenAIRE

    Lukasiewicz, Thomas

    2013-01-01

    We apply the principle of maximum entropy to select a unique joint probability distribution from the set of all joint probability distributions specified by a credal network. In detail, we start by showing that the unique joint distribution of a Bayesian tree coincides with the maximum entropy model of its conditional distributions. This result, however, does not hold anymore for general Bayesian networks. We thus present a new kind of maximum entropy models, which are computed sequentially. ...

  13. 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.)

  14. Public health risk assessment of groundwater contamination in Batman, Turkey.

    Science.gov (United States)

    Nalbantcilar, M Tahir; Pinarkara, Sukru Yavuz

    2016-08-01

    In this study, a comprehensive analysis of groundwater was performed to assess contamination and phenol content in Batman, Turkey, particularly in residential areas near agriculture, livestock and oil industry facilities. From these areas, where potentially contaminated groundwater used for drinking and irrigation threatens public health, 30 groundwater samples were collected and analyzed for heavy metal concentrations (Al, As, B, Ba, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, Li, Mg, Mn, Mo, Na, Ni, NO3, P, Pb, phenol, S, Sb, Se, SO4, Sr, U, and Zn). Compared with the standards of the Environmental Protection Agency, Al, Fe, and Mn concentrations in groundwater exceeded secondary drinking water regulations, NO3 concentrations were high for maximum contaminant levels, and As, Pb, and U concentrations exceeded maximum contaminant level goals in all samples. Ni, Sb, and Se concentrations also exceeded limits set by the Turkish Standards Institution. Nearly all samples revealed concentrations of Se, Sb, Hg, and phenol due to nearby petroleum refineries, oil storage plants, and agricultural and livestock areas. The results obtained from this study indicate that the groundwater in Batman contains elements in concentrations that approach or exceed limits and thus threatens public health with increased blood cholesterol, decreased blood sugar, and circulatory problems.

  15. Methodology for determining acceptable residual radioactive contamination levels at decommissioned nuclear facilities/sites

    International Nuclear Information System (INIS)

    Watson, E.C.; Kennedy, W.E. Jr.; Hoenes, G.R.; Waite, D.A.

    1979-01-01

    The ultimate disposition of decommissioned nuclear facilities and their surrrounding sites depends upon the degree and type of residual contamination. Examination of existing guidelines and regulations has led to the conclusion that there is a need for a general method to derive residual radioactive contamination levels that are acceptable for public use of any decommissioned nuclear facility or site. This paper describes a methodology for determining acceptable residual radioactive contamination levels based on the concept of limiting the annual dose to members of the public. It is not the purpose of this paper to recommend or even propose dose limits for the exposure of the public to residual radioactive contamination left at decommissioned nuclear facilities or sites. Unrestricted release of facilities and/or land is based on the premise that the potential annual dose to any member of the public using this property from all possible exposure pathways will not exceed appropriate limits as may be defined by Federal regulatory agencies. For decommissioned land areas, consideration should be given to people living directly on previously contaminated areas, growing crops, grazing food animals and using well water. Mixtures of radionuclides in the residual contamination representative of fuel reprocessing plants, light water reactors and their respective sites are presented. These mixtures are then used to demonstrate the methodology. Example acceptable residual radioactive contamination levels, based on an assumed maximum annual dose of one millirem, are calculated for several selected times following shutdown of a facility. It is concluded that the methodology presented in this paper results in defensible acceptable residual contamination levels that are directly relatable to risk assessment with the proviso that an acceptable limit to the maximum annual dose will be established. (author)

  16. Ruditapes philippinarum and Ruditapes decussatus under Hg environmental contamination.

    Science.gov (United States)

    Velez, Cátia; Galvão, Petrus; Longo, Renan; Malm, Olaf; Soares, Amadeu M V M; Figueira, Etelvina; Freitas, Rosa

    2015-08-01

    The native species Ruditapes decussatus and the invasive species Ruditapes philippinarum have an important ecological role and socio-economic value, from the Atlantic and Mediterranean to the Indo-Pacific region. In the aquatic environment, they are subjected to the presence of different contaminants, such as mercury (Hg) and its methylated form, methylmercury (MeHg). However, few studies have assessed the impacts of Hg on bivalves under environmental conditions, and little is known on bivalve oxidative stress patterns due to Hg contamination. Therefore, this study aims to assess the Hg contamination in sediments as well as the concentration of Hg and MeHg in R. decussatus and R. philippinarum, and to identify the detoxification strategies of both species living in sympatry, in an aquatic system with historical Hg contamination. The risk to human health due to the consumption of clams was also evaluated. The results obtained demonstrated that total Hg concentration found in sediments from the most contaminated area was higher than the maximum levels established by Sediment Quality Guidelines. This study further revealed that the total Hg and MeHg accumulation in both species was strongly correlated with the total Hg contamination of the sediments. Nonetheless, the THg concentration in both species was lower than maximum permissible limits (MPLs) of THg defined by international organizations. R. decussatus and R. philippinarum showed an increase in lipid peroxidation levels along with the increase of THg accumulation by clams. Nevertheless, for both species, no clear trend was obtained regarding the activity of antioxidant (superoxide dismutase, catalase) and biotransformation (glutathione S-transferase) enzymes and metallothioneins with the increase of THg in clams. Overall, the present work demonstrated that both species can be used as sentinel species of contamination and that the consumption of these clams does not constitute a risk for human health.

  17. Light contamination

    International Nuclear Information System (INIS)

    Cepeda Pena, William Enrique

    1998-01-01

    The article tries on the wrong use of the artificial light, of the main problems of the light contamination, dispersion of the light, noxious effects of the light contamination, ecological effects, effects on the man's biological rhythm, economic effects and effects about the civic and vial security, among other topics

  18. Maximum entropy analysis of liquid diffraction data

    International Nuclear Information System (INIS)

    Root, J.H.; Egelstaff, P.A.; Nickel, B.G.

    1986-01-01

    A maximum entropy method for reducing truncation effects in the inverse Fourier transform of structure factor, S(q), to pair correlation function, g(r), is described. The advantages and limitations of the method are explored with the PY hard sphere structure factor as model input data. An example using real data on liquid chlorine, is then presented. It is seen that spurious structure is greatly reduced in comparison to traditional Fourier transform methods. (author)

  19. Modeling for Airborne Contamination

    International Nuclear Information System (INIS)

    F.R. Faillace; Y. Yuan

    2000-01-01

    The objective of Modeling for Airborne Contamination (referred to from now on as ''this report'') is to provide a documented methodology, along with supporting information, for estimating the release, transport, and assessment of dose to workers from airborne radioactive contaminants within the Monitored Geologic Repository (MGR) subsurface during the pre-closure period. Specifically, this report provides engineers and scientists with methodologies for estimating how concentrations of contaminants might be distributed in the air and on the drift surfaces if released from waste packages inside the repository. This report also provides dose conversion factors for inhalation, air submersion, and ground exposure pathways used to derive doses to potentially exposed subsurface workers. The scope of this report is limited to radiological contaminants (particulate, volatile and gaseous) resulting from waste package leaks (if any) and surface contamination and their transport processes. Neutron activation of air, dust in the air and the rock walls of the drift during the preclosure time is not considered within the scope of this report. Any neutrons causing such activation are not themselves considered to be ''contaminants'' released from the waste package. This report: (1) Documents mathematical models and model parameters for evaluating airborne contaminant transport within the MGR subsurface; and (2) Provides tables of dose conversion factors for inhalation, air submersion, and ground exposure pathways for important radionuclides. The dose conversion factors for air submersion and ground exposure pathways are further limited to drift diameters of 7.62 m and 5.5 m, corresponding to the main and emplacement drifts, respectively. If the final repository design significantly deviates from these drift dimensions, the results in this report may require revision. The dose conversion factors are further derived by using concrete of sufficient thickness to simulate the drift

  20. Maximum Entropy in Drug Discovery

    Directory of Open Access Journals (Sweden)

    Chih-Yuan Tseng

    2014-07-01

    Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

  1. Water Contamination

    Science.gov (United States)

    ... Statistics Training & Education Policy & Recommendations Fast Facts Healthy Water Sites Healthy Water Drinking Water Healthy Swimming Global ... type=”submit” value=”Submit” /> Healthy Water Home Water Contamination Recommend on Facebook Tweet Share Compartir On ...

  2. Inventory and systematization of data on radiation-chemical contamination of rivers running along Bryansk-Belarusian 'cesium spot'

    International Nuclear Information System (INIS)

    Germenchuk, M.G.; Zhukova, O.M.; Bakarykava, Zh.; Popova, E.; Gorbatova, G.

    2005-01-01

    Inventory and systematization of the data on radioactive-chemical contamination of rivers are made. Systematization of the data on chemical and radiation contamination component of rivers was made with using the index of integrated radiation-chemical surface waters contamination (IRCCI=WCI+RCI). Chemical contamination of surface water has been estimated using water contamination index (WCI). It constitutes an integrated magnitude considering ratios of six more significant pollutants to their maximum concentration limits. In dependence on WCI surface water can be attributed to one of seven classes: from 'clean' (with WCI≤1) to 'extremely dirty' (with WCI>10). At present for estimation of radioactive contamination of surface water only comparison with Republican permissible levels are used. But it is not enough for complex estimation of water quality because it does not enable to estimate the extent of radionuclide exceeding over their permissible levels. Therefore for estimation of radioactive pollution level, water radioactive contamination index (RCI) was applied. It is a sum of ratios of main radionuclide concentrations to their permissible levels. Application of RCI enabled to compare radioactive contamination before and after the Chernobyl accident. Application of the index of integrated radiation-chemical surface water contamination enabled to obtain the most complete and impartial estimate of surface water quality of some rivers. Retrospective estimation of the water quality shows that in 1990 surface waters of some rivers should be considered as belonging to more contaminated category of quality if radiation component would have been considered. (authors)

  3. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    60, No. 3. — journal of. March 2003 physics pp. 415–422. Maximum stellar iron core mass. F W GIACOBBE. Chicago Research Center/American Air Liquide ... iron core compression due to the weight of non-ferrous matter overlying the iron cores within large .... thermal equilibrium velocities will tend to be non-relativistic.

  4. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore. 11 refs., 4 figs

  5. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore

  6. A portable storage maximum thermometer

    International Nuclear Information System (INIS)

    Fayart, Gerard.

    1976-01-01

    A clinical thermometer storing the voltage corresponding to the maximum temperature in an analog memory is described. End of the measurement is shown by a lamp switch out. The measurement time is shortened by means of a low thermal inertia platinum probe. This portable thermometer is fitted with cell test and calibration system [fr

  7. Neutron spectra unfolding with maximum entropy and maximum likelihood

    International Nuclear Information System (INIS)

    Itoh, Shikoh; Tsunoda, Toshiharu

    1989-01-01

    A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

  8. The maximum significant wave height in the Southern North Sea

    NARCIS (Netherlands)

    Bouws, E.; Tolman, H.L.; Holthuijsen, L.H.; Eldeberky, Y.; Booij, N.; Ferier, P.

    1995-01-01

    The maximum possible wave conditions along the Dutch coast, which seem to be dominated by the limited water depth, have been estimated in the present study with numerical simulations. Discussions with meteorologists suggest that the maximum possible sustained wind speed in North Sea conditions is

  9. 5 CFR 838.711 - Maximum former spouse survivor annuity.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Maximum former spouse survivor annuity... Orders Awarding Former Spouse Survivor Annuities Limitations on Survivor Annuities § 838.711 Maximum former spouse survivor annuity. (a) Under CSRS, payments under a court order may not exceed the amount...

  10. Food safety of milk and dairy product of dairy cattle from heavy metal contamination

    Science.gov (United States)

    Harlia, E.; Rahmah, KN; Suryanto, D.

    2018-01-01

    Food safety of milk and dairy products is a prerequisite for consumption, which must be free from physical, biological and chemical contamination. Chemical contamination of heavy metals Pb (Plumbum/Lead) and Cd (Cadmium) is generally derived from the environment such as from water, grass, feed additives, medicines and farm equipment. The contamination of milk and dairy products can affect quality and food safety for human consumption. The aim of this research is to investigate contamination of heavy metals Pb and Cd on fresh milk, pasteurized milk, and dodol milk compared with the Maximum Residue Limits (MRL). The methods of this researched was through case study and data obtained analyzed descriptively. Milk samples were obtained from Bandung and surrounding areas. The number of samples used was 30 samples for each product: 30 samples of fresh milk directly obtained from dairy farm, 30 samples of pasteurized milk obtained from street vendors and 30 samples of dodol milk obtained from home industry. Parameters observed were heavy metal residues of Pb and Cd. The results showed that: 1) approximately 83% of fresh milk samples were contaminated by Pb which 57% samples were above MRL and 90% samples were contaminated by Cd above MRL; 2) 67% of pasteurized milk samples were contaminated by Pb below MRL; 3) 60% of dodol milk samples were contaminated by Pb and Cd above MRL.

  11. Field sampling for monitoring migration and defining the areal extent of chemical contamination

    International Nuclear Information System (INIS)

    Thomas, J.M.; Skalski, J.R.; Eberhardt, L.L.; Simmons, M.A.

    1984-11-01

    Initial research on compositing, field designs, and site mapping oriented toward detecting spills and migration at commercial low-level radioactive or chemical waste sites is summarized. Results indicate that the significance test developed to detect samples containing high levels of contamination when they are mixed with several other samples below detectable limits (composites), will be highly effective with large sample sizes when contaminant levels frequently or greatly exceed a maximum acceptable level. These conditions of frequent and high contaminant levels are most likely to occur in regions of a commercial waste site where the priors (previous knowledge) about a spill or migration are highest. Conversely, initial investigations of Bayes sampling strategies suggest that field sampling efforts should be inversely proportional to the priors (expressed as probabilities) for the occurrence of contamination

  12. Antibiotic, Pesticide, and Microbial Contaminants of Honey: Human Health Hazards

    Directory of Open Access Journals (Sweden)

    Noori Al-Waili

    2012-01-01

    Full Text Available Agricultural contamination with pesticides and antibiotics is a challenging problem that needs to be fully addressed. Bee products, such as honey, are widely consumed as food and medicine and their contamination may carry serious health hazards. Honey and other bee products are polluted by pesticides, heavy metals, bacteria and radioactive materials. Pesticide residues cause genetic mutations and cellular degradation and presence of antibiotics might increase resistant human or animal's pathogens. Many cases of infant botulisms have been attributed to contaminated honey. Honey may be very toxic when produced from certain plants. Ingestion of honey without knowing its source and safety might be problematic. Honey should be labeled to explore its origin, composition, and clear statement that it is free from contaminants. Honey that is not subjected for analysis and sterilization should not be used in infants, and should not be applied to wounds or used for medicinal purposes. This article reviews the extent and health impact of honey contamination and stresses on the introduction of a strict monitoring system and validation of acceptable minimal concentrations of pollutants or identifying maximum residue limits for bee products, in particular, honey.

  13. On Maximum Entropy and Inference

    Directory of Open Access Journals (Sweden)

    Luigi Gresele

    2017-11-01

    Full Text Available Maximum entropy is a powerful concept that entails a sharp separation between relevant and irrelevant variables. It is typically invoked in inference, once an assumption is made on what the relevant variables are, in order to estimate a model from data, that affords predictions on all other (dependent variables. Conversely, maximum entropy can be invoked to retrieve the relevant variables (sufficient statistics directly from the data, once a model is identified by Bayesian model selection. We explore this approach in the case of spin models with interactions of arbitrary order, and we discuss how relevant interactions can be inferred. In this perspective, the dimensionality of the inference problem is not set by the number of parameters in the model, but by the frequency distribution of the data. We illustrate the method showing its ability to recover the correct model in a few prototype cases and discuss its application on a real dataset.

  14. Maximum Water Hammer Sensitivity Analysis

    OpenAIRE

    Jalil Emadi; Abbas Solemani

    2011-01-01

    Pressure waves and Water Hammer occur in a pumping system when valves are closed or opened suddenly or in the case of sudden failure of pumps. Determination of maximum water hammer is considered one of the most important technical and economical items of which engineers and designers of pumping stations and conveyance pipelines should take care. Hammer Software is a recent application used to simulate water hammer. The present study focuses on determining significance of ...

  15. Maximum Gene-Support Tree

    Directory of Open Access Journals (Sweden)

    Yunfeng Shan

    2008-01-01

    Full Text Available Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP, minimum evolution (ME, maximum likelihood (ML, and neighbor-joining (NJ—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one, in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1 The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2 There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3 The maximum gene-support tree reflects the phylogenetic relationship among species in comparison.

  16. LCLS Maximum Credible Beam Power

    International Nuclear Information System (INIS)

    Clendenin, J.

    2005-01-01

    The maximum credible beam power is defined as the highest credible average beam power that the accelerator can deliver to the point in question, given the laws of physics, the beam line design, and assuming all protection devices have failed. For a new accelerator project, the official maximum credible beam power is determined by project staff in consultation with the Radiation Physics Department, after examining the arguments and evidence presented by the appropriate accelerator physicist(s) and beam line engineers. The definitive parameter becomes part of the project's safety envelope. This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5 the beam through the matching section and injected into Linac-1 is discussed

  17. Long-term trend of radioactive contamination of food products in Bulgaria after the Chernobyl accident

    International Nuclear Information System (INIS)

    Kirov, K.; Marinov, V.; Naidenov, M.

    1997-01-01

    Results which characterize the dynamics for the power of radioactive contamination of foods in the Bulgaria with Cesium radionuclides from May 1986 to December 1995 are presented. It was done for motivation of some conclusions during the progress of radiation situation in Bulgaria after the Chernobyl accident. The data are compared with Maximum residues limits (MRL) of our country as well as that of international organizations. They are compared with the background contamination of foods descended from regions affected after experimental nuclear explosion till 1963 too

  18. Environmental radioactive contamination

    International Nuclear Information System (INIS)

    Saucedo, Edgardo

    2000-01-01

    The environmental radioactive contamination with the scientific and technological advances can produce big benefits or damages to the human beings or the environment. The approval of national or international laws in the population's education so that it can face the topic critically and the scientific formation of human resources and ethically for application of the ionizing radiations, they are the best road to take advantage to the maximum of benefits of these radiations, reducing to the minimum the risks on the man and the environment

  19. 49 CFR 176.715 - Contamination control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Contamination control. 176.715 Section 176.715... Requirements for Radioactive Materials § 176.715 Contamination control. Each hold, compartment, or deck area... the removable (non-fixed) radioactive surface contamination is not greater than the limits prescribed...

  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. Automatic maximum entropy spectral reconstruction in NMR

    International Nuclear Information System (INIS)

    Mobli, Mehdi; Maciejewski, Mark W.; Gryk, Michael R.; Hoch, Jeffrey C.

    2007-01-01

    Developments in superconducting magnets, cryogenic probes, isotope labeling strategies, and sophisticated pulse sequences together have enabled the application, in principle, of high-resolution NMR spectroscopy to biomolecular systems approaching 1 megadalton. In practice, however, conventional approaches to NMR that utilize the fast Fourier transform, which require data collected at uniform time intervals, result in prohibitively lengthy data collection times in order to achieve the full resolution afforded by high field magnets. A variety of approaches that involve nonuniform sampling have been proposed, each utilizing a non-Fourier method of spectrum analysis. A very general non-Fourier method that is capable of utilizing data collected using any of the proposed nonuniform sampling strategies is maximum entropy reconstruction. A limiting factor in the adoption of maximum entropy reconstruction in NMR has been the need to specify non-intuitive parameters. Here we describe a fully automated system for maximum entropy reconstruction that requires no user-specified parameters. A web-accessible script generator provides the user interface to the system

  2. Contamination shield

    International Nuclear Information System (INIS)

    Bayer, W.; Pecornik, D.

    1982-01-01

    An acrylate resin is presented as contamination protection coating for components and instruments in nuclear facilities and for spent fuel transport containers. The resin is evaporated or sublimated at 130 0 C and can thus be removed easily from the protected component. The radioactive particles entrained during evaporation are retained by suitable filters. (TK) [de

  3. Cotton contamination

    CSIR Research Space (South Africa)

    Van der Sluijs, MHJ

    2018-05-01

    Full Text Available This review focusses on physical forms of contaminant including the presence, prevention and/or removal of foreign bodies, stickiness and seed-coat fragments rather than the type and quantity of chemical residues that might be present in cotton...

  4. Uncertainty of food contamination origin and liability rules: Implications for bargaining power

    OpenAIRE

    Boutouis, M. Z.; Benhassine, W.; Perito, Maria Angela

    2018-01-01

    We propose an industrial organization model to analyze the role of bargaining power and liability rules in creating incentives for downstream and upstream supply chain operators to invest in good practices. We investigate the case in which either upstream production practices or downstream distribution may cause product contamination resulting in noncompliance with the authorized thresholds of residues (maximum residue limit [MRL]). We provide a comparative analysis of the retailers' liabilit...

  5. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based......The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

  6. Cadastral valuation of land contaminated with radionuclides

    Science.gov (United States)

    Ratnikov, A. N.; Sapozhnikov, P. M.; Sanzharova, N. I.; Sviridenko, D. G.; Zhigareva, T. L.; Popova, G. I.; Panov, A. V.; Kozlova, I. Yu.

    2016-01-01

    The methodology and procedure for cadastral valuation of land in the areas contaminated with radionuclides are presented. The efficiency of rehabilitation measures applied to decrease crop contamination to the levels satisfying sanitary-hygienic norms is discussed. The differentiation of cadastral value of radioactively contaminated agricultural lands for the particular farms and land plots is suggested. An example of cadastral valuation of agricultural land contaminated during the Chernobyl Nuclear Power Plant accident is given. It is shown that the use of sandy and loamy sandy soddy-podzolic soils with the 137Cs contamination of 37-185 and >185 kBq/m2 for crop growing is unfeasible. The growing of grain crops and potatoes on clay loamy soddy-podzolic soils with the 137Cs contamination of 555-740 kBq/m2 is unprofitable. The maximum cadastral value of radioactively contaminated lands is typical of leached chernozems.

  7. Extreme Maximum Land Surface Temperatures.

    Science.gov (United States)

    Garratt, J. R.

    1992-09-01

    There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

  8. 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

    A new standard submitted by the Health Physics Society Standards Committee to the American National Standards Institute concerning radioactive surface contamination of materials and equipment is discussed. The chronological events in the development of this standard are given. The standard provides criteria for the release for uncontrolled use of materials, equipment and facilities contaminated or potentially contaminated with radioactivity. Permissible contamination limits are specified for: 1) long lived alpha emitters except natural uranium and thorium, 2) more hazardous beta-gamma emitters, 3) less hazardous beta-gamma emitters and 4) natural uranium and thorium. A contamination reference level of 1000 dpm/100 cm 2 for 90 Sr was set as the basis for assigning limits to radionuclides presenting an ingestion hazard and other radionuclides were grouped based on the values of their maximum permissible concentration (MPC) in water relative to 90 Sr. The contamination limit for 239 Pu was chosen as the basis for assigning limits based on MPC in air to radionuclides presenting an inhalation hazard; a value of 100 dpm/100 cm 2 was adopted in the standard. An upper limit of 5000 dpm/100 cm 2 for surface contamination was selected for the standard. (UK)

  9. System for memorizing maximum values

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1992-08-01

    The invention discloses a system capable of memorizing maximum sensed values. The system includes conditioning circuitry which receives the analog output signal from a sensor transducer. The conditioning circuitry rectifies and filters the analog signal and provides an input signal to a digital driver, which may be either linear or logarithmic. The driver converts the analog signal to discrete digital values, which in turn triggers an output signal on one of a plurality of driver output lines n. The particular output lines selected is dependent on the converted digital value. A microfuse memory device connects across the driver output lines, with n segments. Each segment is associated with one driver output line, and includes a microfuse that is blown when a signal appears on the associated driver output line.

  10. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  11. Scintillation counter, maximum gamma aspect

    International Nuclear Information System (INIS)

    Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  12. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yi; Zhao, Shiguang; Gao, Xin

    2014-01-01

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  13. Fatores limitantes ao crescimento do capim-Tanzânia em um sistema agrossilvipastoril com eucalipto, na região dos Cerrados de Minas Gerais Factors limiting the growth of Panicum maximum cv. Tanzânia-1 in an agrosilvopastoral system with eucalypt, in the Cerrados of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Soares de Andrade

    2001-07-01

    accumulation was twice superior compared to control, showing that the grass growth was being restricted by the low N availability in the soil. The high response to the N fertilization showed that the shading was not the only factor limiting the understorey productivity and, also, that the established Panicum maximum plants were not being negative and significantly affected by allelopathic substances produced by eucalypts.

  14. Should legislation regarding maximum Pb and Cd levels in human food also cover large game meat?

    Science.gov (United States)

    Taggart, Mark A; Reglero, Manuel M; Camarero, Pablo R; Mateo, Rafael

    2011-01-01

    Game meat may be contaminated with metals and metalloids if animals reside in anthropogenically polluted areas, or if ammunition used to kill the game contaminates the meat. Muscle tissue from red deer and wild boar shot in Ciudad Real province (Spain) in 2005-06 was analysed for As, Pb, Cu, Zn, Se and Cd. Samples were collected from hunting estates within and outside an area that has been historically used for mining, smelting and refining various metals and metalloids. Meat destined for human consumption, contained more Pb, As and Se (red deer) and Pb (boar) when harvested from animals that had resided in mined areas. Age related accumulation of Cd, Zn and As (in deer) and Cd, Cu and Se (in boar) was also observed. Two boar meat samples contained high Pb, at 352 and 2408 μg/g d.w., and these were likely to have been contaminated by Pb ammunition. Likewise, 19-84% of all samples (depending on species and sampling area) had Pb levels > 0.1 μg/g w.w., the EU maximum residue level (MRL) for farm reared meat. Between 9 and 43% of samples exceeded comparable Cd limits. Such data highlight a discrepancy between what is considered safe for human consumption in popular farmed meat (chicken, beef, lamb), and what in game may often exist. A risk assessment is presented which describes the number of meals required to exceed current tolerable weekly intakes (PTWIs) for Pb and Cd, and the potential contribution of large game consumption to such intake limit criteria. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Subsurface Contamination Control

    Energy Technology Data Exchange (ETDEWEB)

    Y. Yuan

    2001-12-12

    There are two objectives of this report, ''Subsurface Contamination Control''. The first is to provide a technical basis for recommending limiting radioactive contamination levels (LRCL) on the external surfaces of waste packages (WP) for acceptance into the subsurface repository. The second is to provide an evaluation of the magnitude of potential releases from a defective WP and the detectability of the released contents. The technical basis for deriving LRCL has been established in ''Retrieval Equipment and Strategy for Wp on Pallet'' (CRWMS M and O 2000g, 6.3.1). This report updates the derivation by incorporating the latest design information of the subsurface repository for site recommendation. The derived LRCL on the external surface of WPs, therefore, supercede that described in CRWMS M and O 2000g. The derived LRCL represent the average concentrations of contamination on the external surfaces of each WP that must not be exceeded before the WP is to be transported to the subsurface facility for emplacement. The evaluation of potential releases is necessary to control the potential contamination of the subsurface repository and to detect prematurely failed WPs. The detection of failed WPs is required in order to provide reasonable assurance that the integrity of each WP is intact prior to MGR closure. An emplaced WP may become breached due to manufacturing defects or improper weld combined with failure to detect the defect, by corrosion, or by mechanical penetration due to accidents or rockfall conditions. The breached WP may release its gaseous and volatile radionuclide content to the subsurface environment and result in contaminating the subsurface facility. The scope of this analysis is limited to radioactive contaminants resulting from breached WPs during the preclosure period of the subsurface repository. This report: (1) documents a method for deriving LRCL on the external surfaces of WP for acceptance into the

  16. Direct probability mapping of contaminants

    International Nuclear Information System (INIS)

    Rautman, C.A.

    1993-01-01

    Exhaustive characterization of a contaminated site is a physical and practical impossibility. Descriptions of the nature, extent, and level of contamination, as well as decisions regarding proposed remediation activities, must be made in a state of uncertainty based upon limited physical sampling. Geostatistical simulation provides powerful tools for investigating contaminant levels, and in particular, for identifying and using the spatial interrelationships among a set of isolated sample values. This additional information can be used to assess the likelihood of encountering contamination at unsampled locations and to evaluate the risk associated with decisions to remediate or not to remediate specific regions within a site. Past operation of the DOE Feed Materials Production Center has contaminated a site near Fernald, Ohio, with natural uranium. Soil geochemical data have been collected as part of the Uranium-in-Soils Integrated Demonstration Project. These data have been used to construct a number of stochastic images of potential contamination for parcels approximately the size of a selective remediation unit. Each such image accurately reflects the actual measured sample values, and reproduces the univariate statistics and spatial character of the extant data. Post-processing of a large number of these equally likely, statistically similar images produces maps directly showing the probability of exceeding specified levels of contamination. Evaluation of the geostatistical simulations can yield maps representing the expected magnitude of the contamination for various regions and other information that may be important in determining a suitable remediation process or in sizing equipment to accomplish the restoration

  17. Maximum entropy and Bayesian methods

    International Nuclear Information System (INIS)

    Smith, C.R.; Erickson, G.J.; Neudorfer, P.O.

    1992-01-01

    Bayesian probability theory and Maximum Entropy methods are at the core of a new view of scientific inference. These 'new' ideas, along with the revolution in computational methods afforded by modern computers allow astronomers, electrical engineers, image processors of any type, NMR chemists and physicists, and anyone at all who has to deal with incomplete and noisy data, to take advantage of methods that, in the past, have been applied only in some areas of theoretical physics. The title workshops have been the focus of a group of researchers from many different fields, and this diversity is evident in this book. There are tutorial and theoretical papers, and applications in a very wide variety of fields. Almost any instance of dealing with incomplete and noisy data can be usefully treated by these methods, and many areas of theoretical research are being enhanced by the thoughtful application of Bayes' theorem. Contributions contained in this volume present a state-of-the-art overview that will be influential and useful for many years to come

  18. Air contamination analysis during emergency medical treatment

    International Nuclear Information System (INIS)

    Yamada, Y.; Fukutsu, K.; Yuuki, M.; Akashi, M.

    2009-01-01

    After radiological emergencies, patients contaminated with radioactivity are taken to radiation emergency hospitals for treatment. Numerical simulations using the computer software 'Flow Designer R were made in order to evaluate indoor air contamination caused by the breathing out of contaminated air. The National Inst. of Radiological Sciences facility was used for the numerical evaluation. Results indicate that the dispersion of contaminated air depends on the characteristics of the contaminants, and that the dispersion range was limited and localised. Only medical staff standing in a special position near the patient was exposed to almost un-diluted contaminated air. Highly contaminated air was evacuated with a local exhaust pump system. Room air quality was monitored using a continuous air sampling system, but it was found that the sampling point was not representative for the purpose of radiation protection. From the air-flow analysis, some problems that affect radiological safety were revealed and valuable information and measures for preventing secondary contamination were determined. (authors)

  19. Contamination Analyzer

    Science.gov (United States)

    1994-01-01

    Measurement of the total organic carbon content in water is important in assessing contamination levels in high purity water for power generation, pharmaceutical production and electronics manufacture. Even trace levels of organic compounds can cause defects in manufactured products. The Sievers Model 800 Total Organic Carbon (TOC) Analyzer, based on technology developed for the Space Station, uses a strong chemical oxidizing agent and ultraviolet light to convert organic compounds in water to carbon dioxide. After ionizing the carbon dioxide, the amount of ions is determined by measuring the conductivity of the deionized water. The new technique is highly sensitive, does not require compressed gas, and maintenance is minimal.

  20. Map of radioactive contamination in mushrooms of Poland in 1991

    International Nuclear Information System (INIS)

    Mietelski, J.W.; Jasinska, M.; Kubica, B.; Kozak, K.; Macharski, P.

    1992-01-01

    Results from part of the Polish Government programme for forests radioactive contamination studies are presented. 278 samples of edible mushroom (Xerocomus badius) were analysed for radiocesium 137 Cs and 134 Cs) and 40 K using low-background gamma spectrometer with a germanium detector. Samples were collected from all districts of Poland in October 1991 by forest inspectors. In consequence maps of 137 Cs, 134 Cs and for 40 K concentration in ''Xerocomus badius'' are presented. The method of measurements is also presented. Large differences in radiocesium contamination levels are observed for various parts of the country. The higher radiocesium contamination level is observed in Czestochowa-Opole region. Maximum value for 137 Cs is equal to 157 kBq/kg d.m. and that for 134 Cs is equal to 16.3 kBq/kg d.m. The 40 K content level is nearly constant and equal to c.a. 1.3 kBq/kg d.m. Minimum values for caesium contamination were observed in the Bieszczady Mountains. The effective dose equivalent estimation due to the consumption of mushrooms is performed. The limits of ingestion amounts are calculated. (author). 15 refs, 15 figs, 6 tabs

  1. Fungic microflora of Panicum maximum and Styosanthes spp. commercial seed / Microflora fúngica de sementes comerciais de Panicum maximum e Stylosanthes spp.

    Directory of Open Access Journals (Sweden)

    Larissa Rodrigues Fabris

    2010-09-01

    Full Text Available The sanitary quality of 26 lots commercial seeds of tropical forages, produced in different regions (2004-05 and 2005-06 was analyzed. The lots were composed of seeds of Panicum maximum ('Massai', 'Mombaça' e 'Tanzânia' and stylo ('Estilosantes Campo Grande' - ECG. Additionally, seeds of two lots of P. maximum for exportation were analyzed. The blotter test was used, at 20ºC under alternating light and darkness in a 12 h photoperiod, for seven days. The Aspergillus, Cladosporium and Rhizopus genus consisted the secondary or saprophytes fungi (FSS with greatest frequency in P. maximum lots. In general, there was low incidence of these fungus in the seeds. In relation to pathogenic fungi (FP, it was detected high frequency of contaminated lots by Bipolaris, Curvularia, Fusarium and Phoma genus. Generally, there was high incidence of FP in P. maximum seeds. The occurrence of Phoma sp. was hight, because in 81% of the lots showed incidence superior to 50%. In 'ECG' seeds it was detected FSS (Aspergillus, Cladosporium, and Penicillium genus and FP (Bipolaris, Curvularia, Fusarium and Phoma genus, usually, in low incidence. FSS and FP were associated to P. maximum seeds for exportation, with significant incidence in some cases. The results indicated that there was a limiting factor in all producer regions regarding sanitary quality of the seeds.Sementes comerciais de forrageiras tropicais, pertencente a 26 lotes produzidos em diferentes regiões (safras 2004-05 e 2005-06, foram avaliadas quanto à sanidade. Foram analisadas sementes de cultivares de Panicum maximum (Massai, Mombaça e Tanzânia e de estilosantes (Estilosantes Campo Grande – ECG. Adicionalmente, avaliou-se a qualidade sanitária de dois lotes de sementes de P. maximum destinados à exportação. Para isso, as sementes foram submetidas ao teste de papel de filtro em gerbox, os quais foram incubados a 20ºC, com fotoperíodo de 12 h, durante sete dias. Os fungos saprófitos ou

  2. What controls the maximum magnitude of injection-induced earthquakes?

    Science.gov (United States)

    Eaton, D. W. S.

    2017-12-01

    Three different approaches for estimation of maximum magnitude are considered here, along with their implications for managing risk. The first approach is based on a deterministic limit for seismic moment proposed by McGarr (1976), which was originally designed for application to mining-induced seismicity. This approach has since been reformulated for earthquakes induced by fluid injection (McGarr, 2014). In essence, this method assumes that the upper limit for seismic moment release is constrained by the pressure-induced stress change. A deterministic limit is given by the product of shear modulus and the net injected fluid volume. This method is based on the assumptions that the medium is fully saturated and in a state of incipient failure. An alternative geometrical approach was proposed by Shapiro et al. (2011), who postulated that the rupture area for an induced earthquake falls entirely within the stimulated volume. This assumption reduces the maximum-magnitude problem to one of estimating the largest potential slip surface area within a given stimulated volume. Finally, van der Elst et al. (2016) proposed that the maximum observed magnitude, statistically speaking, is the expected maximum value for a finite sample drawn from an unbounded Gutenberg-Richter distribution. These three models imply different approaches for risk management. The deterministic method proposed by McGarr (2014) implies that a ceiling on the maximum magnitude can be imposed by limiting the net injected volume, whereas the approach developed by Shapiro et al. (2011) implies that the time-dependent maximum magnitude is governed by the spatial size of the microseismic event cloud. Finally, the sample-size hypothesis of Van der Elst et al. (2016) implies that the best available estimate of the maximum magnitude is based upon observed seismicity rate. The latter two approaches suggest that real-time monitoring is essential for effective management of risk. A reliable estimate of maximum

  3. Maximum entropy principal for transportation

    International Nuclear Information System (INIS)

    Bilich, F.; Da Silva, R.

    2008-01-01

    In this work we deal with modeling of the transportation phenomenon for use in the transportation planning process and policy-impact studies. The model developed is based on the dependence concept, i.e., the notion that the probability of a trip starting at origin i is dependent on the probability of a trip ending at destination j given that the factors (such as travel time, cost, etc.) which affect travel between origin i and destination j assume some specific values. The derivation of the solution of the model employs the maximum entropy principle combining a priori multinomial distribution with a trip utility concept. This model is utilized to forecast trip distributions under a variety of policy changes and scenarios. The dependence coefficients are obtained from a regression equation where the functional form is derived based on conditional probability and perception of factors from experimental psychology. The dependence coefficients encode all the information that was previously encoded in the form of constraints. In addition, the dependence coefficients encode information that cannot be expressed in the form of constraints for practical reasons, namely, computational tractability. The equivalence between the standard formulation (i.e., objective function with constraints) and the dependence formulation (i.e., without constraints) is demonstrated. The parameters of the dependence-based trip-distribution model are estimated, and the model is also validated using commercial air travel data in the U.S. In addition, policy impact analyses (such as allowance of supersonic flights inside the U.S. and user surcharge at noise-impacted airports) on air travel are performed.

  4. Exercise-induced maximum metabolic rate scaled to body mass by ...

    African Journals Online (AJOL)

    Exercise-induced maximum metabolic rate scaled to body mass by the fractal ... rate scaling is that exercise-induced maximum aerobic metabolic rate (MMR) is ... muscle stress limitation, and maximized oxygen delivery and metabolic rates.

  5. Probability mapping of contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Rautman, C.A.; Kaplan, P.G. [Sandia National Labs., Albuquerque, NM (United States); McGraw, M.A. [Univ. of California, Berkeley, CA (United States); Istok, J.D. [Oregon State Univ., Corvallis, OR (United States); Sigda, J.M. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    1994-04-01

    Exhaustive characterization of a contaminated site is a physical and practical impossibility. Descriptions of the nature, extent, and level of contamination, as well as decisions regarding proposed remediation activities, must be made in a state of uncertainty based upon limited physical sampling. The probability mapping approach illustrated in this paper appears to offer site operators a reasonable, quantitative methodology for many environmental remediation decisions and allows evaluation of the risk associated with those decisions. For example, output from this approach can be used in quantitative, cost-based decision models for evaluating possible site characterization and/or remediation plans, resulting in selection of the risk-adjusted, least-cost alternative. The methodology is completely general, and the techniques are applicable to a wide variety of environmental restoration projects. The probability-mapping approach is illustrated by application to a contaminated site at the former DOE Feed Materials Production Center near Fernald, Ohio. Soil geochemical data, collected as part of the Uranium-in-Soils Integrated Demonstration Project, have been used to construct a number of geostatistical simulations of potential contamination for parcels approximately the size of a selective remediation unit (the 3-m width of a bulldozer blade). Each such simulation accurately reflects the actual measured sample values, and reproduces the univariate statistics and spatial character of the extant data. Post-processing of a large number of these equally likely statistically similar images produces maps directly showing the probability of exceeding specified levels of contamination (potential clean-up or personnel-hazard thresholds).

  6. Probability mapping of contaminants

    International Nuclear Information System (INIS)

    Rautman, C.A.; Kaplan, P.G.; McGraw, M.A.; Istok, J.D.; Sigda, J.M.

    1994-01-01

    Exhaustive characterization of a contaminated site is a physical and practical impossibility. Descriptions of the nature, extent, and level of contamination, as well as decisions regarding proposed remediation activities, must be made in a state of uncertainty based upon limited physical sampling. The probability mapping approach illustrated in this paper appears to offer site operators a reasonable, quantitative methodology for many environmental remediation decisions and allows evaluation of the risk associated with those decisions. For example, output from this approach can be used in quantitative, cost-based decision models for evaluating possible site characterization and/or remediation plans, resulting in selection of the risk-adjusted, least-cost alternative. The methodology is completely general, and the techniques are applicable to a wide variety of environmental restoration projects. The probability-mapping approach is illustrated by application to a contaminated site at the former DOE Feed Materials Production Center near Fernald, Ohio. Soil geochemical data, collected as part of the Uranium-in-Soils Integrated Demonstration Project, have been used to construct a number of geostatistical simulations of potential contamination for parcels approximately the size of a selective remediation unit (the 3-m width of a bulldozer blade). Each such simulation accurately reflects the actual measured sample values, and reproduces the univariate statistics and spatial character of the extant data. Post-processing of a large number of these equally likely statistically similar images produces maps directly showing the probability of exceeding specified levels of contamination (potential clean-up or personnel-hazard thresholds)

  7. Internal radioactive contamination treatment

    International Nuclear Information System (INIS)

    Tobajas, L. M.

    1998-01-01

    In a radiological emergency, the internal radioactive contamination becomes a therapeutic urgency and must be established as fast as possible. Just when a radioactive contamination accident occurs, it is difficult to know exactly the amount of radioactive materials absorbed and to estimate the dose received.. The decision to be taken after the incorporation of the radioactive material depends on the method and on the Radiological Protection Department collaboration. Any treatment achieving a reduction of the doses received or expected will be useful. The International Radiological Protection Commission doesn't recommend the use of the dose limit, to decide about the intervention necessity. However the LIA can be used as the reference point to establish the necessity and reach of the treatment. The object of the present work, is to introduce the general principles to carry out the internal people decontamination, under the last international recommendations. (Author) 4 refs

  8. Last Glacial Maximum Salinity Reconstruction

    Science.gov (United States)

    Homola, K.; Spivack, A. J.

    2016-12-01

    It has been previously demonstrated that salinity can be reconstructed from sediment porewater. The goal of our study is to reconstruct high precision salinity during the Last Glacial Maximum (LGM). Salinity is usually determined at high precision via conductivity, which requires a larger volume of water than can be extracted from a sediment core, or via chloride titration, which yields lower than ideal precision. It has been demonstrated for water column samples that high precision density measurements can be used to determine salinity at the precision of a conductivity measurement using the equation of state of seawater. However, water column seawater has a relatively constant composition, in contrast to porewater, where variations from standard seawater composition occur. These deviations, which affect the equation of state, must be corrected for through precise measurements of each ion's concentration and knowledge of apparent partial molar density in seawater. We have developed a density-based method for determining porewater salinity that requires only 5 mL of sample, achieving density precisions of 10-6 g/mL. We have applied this method to porewater samples extracted from long cores collected along a N-S transect across the western North Atlantic (R/V Knorr cruise KN223). Density was determined to a precision of 2.3x10-6 g/mL, which translates to salinity uncertainty of 0.002 gms/kg if the effect of differences in composition is well constrained. Concentrations of anions (Cl-, and SO4-2) and cations (Na+, Mg+, Ca+2, and K+) were measured. To correct salinities at the precision required to unravel LGM Meridional Overturning Circulation, our ion precisions must be better than 0.1% for SO4-/Cl- and Mg+/Na+, and 0.4% for Ca+/Na+, and K+/Na+. Alkalinity, pH and Dissolved Inorganic Carbon of the porewater were determined to precisions better than 4% when ratioed to Cl-, and used to calculate HCO3-, and CO3-2. Apparent partial molar densities in seawater were

  9. Maximum Parsimony on Phylogenetic networks

    Science.gov (United States)

    2012-01-01

    Background Phylogenetic networks are generalizations of phylogenetic trees, that are used to model evolutionary events in various contexts. Several different methods and criteria have been introduced for reconstructing phylogenetic trees. Maximum Parsimony is a character-based approach that infers a phylogenetic tree by minimizing the total number of evolutionary steps required to explain a given set of data assigned on the leaves. Exact solutions for optimizing parsimony scores on phylogenetic trees have been introduced in the past. Results In this paper, we define the parsimony score on networks as the sum of the substitution costs along all the edges of the network; and show that certain well-known algorithms that calculate the optimum parsimony score on trees, such as Sankoff and Fitch algorithms extend naturally for networks, barring conflicting assignments at the reticulate vertices. We provide heuristics for finding the optimum parsimony scores on networks. Our algorithms can be applied for any cost matrix that may contain unequal substitution costs of transforming between different characters along different edges of the network. We analyzed this for experimental data on 10 leaves or fewer with at most 2 reticulations and found that for almost all networks, the bounds returned by the heuristics matched with the exhaustively determined optimum parsimony scores. Conclusion The parsimony score we define here does not directly reflect the cost of the best tree in the network that displays the evolution of the character. However, when searching for the most parsimonious network that describes a collection of characters, it becomes necessary to add additional cost considerations to prefer simpler structures, such as trees over networks. The parsimony score on a network that we describe here takes into account the substitution costs along the additional edges incident on each reticulate vertex, in addition to the substitution costs along the other edges which are

  10. LANSCE beam current limiter

    International Nuclear Information System (INIS)

    Gallegos, F.R.

    1996-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described

  11. Two-dimensional maximum entropy image restoration

    International Nuclear Information System (INIS)

    Brolley, J.E.; Lazarus, R.B.; Suydam, B.R.; Trussell, H.J.

    1977-07-01

    An optical check problem was constructed to test P LOG P maximum entropy restoration of an extremely distorted image. Useful recovery of the original image was obtained. Comparison with maximum a posteriori restoration is made. 7 figures

  12. Treatment of plutonium contaminations

    International Nuclear Information System (INIS)

    Lafuma, J.

    1983-01-01

    Three kinds of plutonium contaminations were considered: skin contamination; contaminated wounds; contamination by inhalation. The treatment of these contaminations was studied for insoluble (oxide and metal forms) and soluble plutonium (complexes). The use of DTPA and therapeutic problems encountered with stable plutonium complexes were analyzed. The new possibilities of internal decontamination using Puchel and LICAM were evaluated [fr

  13. Determination of the maximum-depth to potential field sources by a maximum structural index method

    Science.gov (United States)

    Fedi, M.; Florio, G.

    2013-01-01

    A simple and fast determination of the limiting depth to the sources may represent a significant help to the data interpretation. To this end we explore the possibility of determining those source parameters shared by all the classes of models fitting the data. One approach is to determine the maximum depth-to-source compatible with the measured data, by using for example the well-known Bott-Smith rules. These rules involve only the knowledge of the field and its horizontal gradient maxima, and are independent from the density contrast. Thanks to the direct relationship between structural index and depth to sources we work out a simple and fast strategy to obtain the maximum depth by using the semi-automated methods, such as Euler deconvolution or depth-from-extreme-points method (DEXP). The proposed method consists in estimating the maximum depth as the one obtained for the highest allowable value of the structural index (Nmax). Nmax may be easily determined, since it depends only on the dimensionality of the problem (2D/3D) and on the nature of the analyzed field (e.g., gravity field or magnetic field). We tested our approach on synthetic models against the results obtained by the classical Bott-Smith formulas and the results are in fact very similar, confirming the validity of this method. However, while Bott-Smith formulas are restricted to the gravity field only, our method is applicable also to the magnetic field and to any derivative of the gravity and magnetic field. Our method yields a useful criterion to assess the source model based on the (∂f/∂x)max/fmax ratio. The usefulness of the method in real cases is demonstrated for a salt wall in the Mississippi basin, where the estimation of the maximum depth agrees with the seismic information.

  14. Eliminating PCR contamination

    International Nuclear Information System (INIS)

    Fox, J.C.; Ait-Khaled, Mounir; Webster, Alison; Emery, V.C.

    1991-01-01

    The sensitivity of polymerase chain reaction (PCR) can mean that even very low levels of contamination with the target DNA will result in a positive signal. At present this aspect is a major limitation in the use of PCR as a routine diagnostic method. By exposing PCR reagents to UV light, contaminating DNA can be inactivated, thus providing an opportunity to eradicate false positive reactions. UV irradiation was applied to PCR systems used for detection of human cytomegalovirus CMV and human immunodeficiency virus (HIV) and shown to be effective in eradicating both laboratory encountered contamination and plasmid DNA (below 100 pg) added to PCR systems prior to UV exposure. Sensitivity of a PCR system to amplify the long terminal repeat (LTR) sequence of HIV-1 was not affected by the irradiation procedure; however, ultimate sensitivity of a PCR system for the amplification of an early gene pro-motor sequence of the CMV genome was reduced 1000-fold. UV irradiation did not affect the size of the PCR product as determined by strand separating polyacrylamide gel electrophoresis of a 32 P-labelled amplimer. Thus, a simple pre-exposure to UV light would seem a worth-wile step to incorporate into PCR protocols provided that the effects on sensitivity have been determined empirically for each PCR system. (author). 11 refs.; 3 figs

  15. Combining Experiments and Simulations Using the Maximum Entropy Principle

    DEFF Research Database (Denmark)

    Boomsma, Wouter; Ferkinghoff-Borg, Jesper; Lindorff-Larsen, Kresten

    2014-01-01

    are not in quantitative agreement with experimental data. The principle of maximum entropy is a general procedure for constructing probability distributions in the light of new data, making it a natural tool in cases when an initial model provides results that are at odds with experiments. The number of maximum entropy...... in the context of a simple example, after which we proceed with a real-world application in the field of molecular simulations, where the maximum entropy procedure has recently provided new insight. Given the limited accuracy of force fields, macromolecular simulations sometimes produce results....... Three very recent papers have explored this problem using the maximum entropy approach, providing both new theoretical and practical insights to the problem. We highlight each of these contributions in turn and conclude with a discussion on remaining challenges....

  16. Receiver function estimated by maximum entropy deconvolution

    Institute of Scientific and Technical Information of China (English)

    吴庆举; 田小波; 张乃铃; 李卫平; 曾融生

    2003-01-01

    Maximum entropy deconvolution is presented to estimate receiver function, with the maximum entropy as the rule to determine auto-correlation and cross-correlation functions. The Toeplitz equation and Levinson algorithm are used to calculate the iterative formula of error-predicting filter, and receiver function is then estimated. During extrapolation, reflective coefficient is always less than 1, which keeps maximum entropy deconvolution stable. The maximum entropy of the data outside window increases the resolution of receiver function. Both synthetic and real seismograms show that maximum entropy deconvolution is an effective method to measure receiver function in time-domain.

  17. Contamination vs. Exposure

    Science.gov (United States)

    ... into the environment can cause air, water, surfaces, soil, plants, buildings, people, or animals to become contaminated. ... water to remove contamination. This process is called decontamination. Try to avoid spreading contamination to parts of ...

  18. Maximum Power from a Solar Panel

    Directory of Open Access Journals (Sweden)

    Michael Miller

    2010-01-01

    Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

  19. Revision of regional maximum flood (RMF) estimation in Namibia ...

    African Journals Online (AJOL)

    Extreme flood hydrology in Namibia for the past 30 years has largely been based on the South African Department of Water Affairs Technical Report 137 (TR 137) of 1988. This report proposes an empirically established upper limit of flood peaks for regions called the regional maximum flood (RMF), which could be ...

  20. Combining Experiments and Simulations Using the Maximum Entropy Principle

    DEFF Research Database (Denmark)

    Boomsma, Wouter; Ferkinghoff-Borg, Jesper; Lindorff-Larsen, Kresten

    2014-01-01

    in the context of a simple example, after which we proceed with a real-world application in the field of molecular simulations, where the maximum entropy procedure has recently provided new insight. Given the limited accuracy of force fields, macromolecular simulations sometimes produce results...

  1. Fusarium graminearum in Stored Wheat: Use of CO2 Production to Quantify Dry Matter Losses and Relate This to Relative Risks of Zearalenone Contamination under Interacting Environmental Conditions

    Directory of Open Access Journals (Sweden)

    Esther Garcia-Cela

    2018-02-01

    Full Text Available Zearalenone (ZEN contamination from Fusarium graminearum colonization is particularly important in food and feed wheat, especially during post-harvest storage with legislative limits for both food and feed grain. Indicators of the relative risk from exceeding these limits would be useful. We examined the effect of different water activities (aw; 0.95–0.90 and temperature (10–25 °C in naturally contaminated and irradiated wheat grain, both inoculated with F. graminearum and stored for 15 days on (a respiration rate; (b dry matter losses (DML; (c ZEN production and (d relationship between DML and ZEN contamination relative to the EU legislative limits. Gas Chromatography was used to measure the temporal respiration rates and the total accumulated CO2 production. There was an increase in temporal CO2 production rates in wetter and warmer conditions in all treatments, with the highest respiration in the 25 °C × 0.95 aw treatments + F. graminearum inoculation. This was reflected in the total accumulated CO2 in the treatments. The maximum DMLs were in the 0.95 aw/20–25 °C treatments and at 10 °C/0.95 aw. The DMLs were modelled to produce contour maps of the environmental conditions resulting in maximum/minimum losses. Contamination with ZEN/ZEN-related compounds were quantified. Maximum production was at 25 °C/0.95–0.93 aw and 20 °C/0.95 aw. ZEN contamination levels plotted against DMLs for all the treatments showed that at ca. <1.0% DML, there was a low risk of ZEN contamination exceeding EU legislative limits, while at >1.0% DML, the risk was high. This type of data is important in building a database for the development of a post-harvest decision support system for relative risks of different mycotoxins.

  2. 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)

  3. Treatment techniques for the removal of radioactive contaminants from drinking water

    International Nuclear Information System (INIS)

    Logsdon, Gary S.

    1978-01-01

    Maximum contaminant levels have been set for radioactive contaminants, as required by the Safe Drinking Water Act (PL 93-523). Treatment techniques are available for removing radium and beta-gamma emitters. Presently-used methods of removing radium-226 are precipitative lime softening (80-90% removal) ion exchange softening (95% removal) and reverse osmosis (95% removal). The 5 p Ci/l limit for radium can be met with conventional technology for raw waters in the 5-100 p Ci/l concentration range. Treatment for removal of beta or gamma emitters must be based upon chemical rather than radioactive characteristics of the contaminant. Reverse osmosis can remove a broad spectrum of ions and molecules from water, so it is the process most likely to be used. The maximum contaminant level for beta and gamma radioactivity is an annual dose equivalent to the total body or any organ not to exceed 4 m rem/year. The fate of radionuclides after removal from drinking water should be considered. Presently radium is disposed with other process wastes at softening plants removing radium. Confinement and disposal as a radioactive waste would be very expensive. (author)

  4. Maximum mass of magnetic white dwarfs

    International Nuclear Information System (INIS)

    Paret, Daryel Manreza; Horvath, Jorge Ernesto; Martínez, Aurora Perez

    2015-01-01

    We revisit the problem of the maximum masses of magnetized white dwarfs (WDs). The impact of a strong magnetic field on the structure equations is addressed. The pressures become anisotropic due to the presence of the magnetic field and split into parallel and perpendicular components. We first construct stable solutions of the Tolman-Oppenheimer-Volkoff equations for parallel pressures and find that physical solutions vanish for the perpendicular pressure when B ≳ 10 13 G. This fact establishes an upper bound for a magnetic field and the stability of the configurations in the (quasi) spherical approximation. Our findings also indicate that it is not possible to obtain stable magnetized WDs with super-Chandrasekhar masses because the values of the magnetic field needed for them are higher than this bound. To proceed into the anisotropic regime, we can apply results for structure equations appropriate for a cylindrical metric with anisotropic pressures that were derived in our previous work. From the solutions of the structure equations in cylindrical symmetry we have confirmed the same bound for B ∼ 10 13 G, since beyond this value no physical solutions are possible. Our tentative conclusion is that massive WDs with masses well beyond the Chandrasekhar limit do not constitute stable solutions and should not exist. (paper)

  5. Contaminant exposure in terrestrial vertebrates

    International Nuclear Information System (INIS)

    Smith, Philip N.; Cobb, George P.; Godard-Codding, Celine; Hoff, Dale; McMurry, Scott T.; Rainwater, Thomas R.; Reynolds, Kevin D.

    2007-01-01

    Here we review mechanisms and factors influencing contaminant exposure among terrestrial vertebrate wildlife. There exists a complex mixture of biotic and abiotic factors that dictate potential for contaminant exposure among terrestrial and semi-terrestrial vertebrates. Chemical fate and transport in the environment determine contaminant bioaccessibility. Species-specific natural history characteristics and behavioral traits then play significant roles in the likelihood that exposure pathways, from source to receptor, are complete. Detailed knowledge of natural history traits of receptors considered in conjunction with the knowledge of contaminant behavior and distribution on a site are critical when assessing and quantifying exposure. We review limitations in our understanding of elements of exposure and the unique aspects of exposure associated with terrestrial and semi-terrestrial taxa. We provide insight on taxa-specific traits that contribute, or limit exposure to, transport phenomenon that influence exposure throughout terrestrial systems, novel contaminants, bioavailability, exposure data analysis, and uncertainty associated with exposure in wildlife risk assessments. Lastly, we identify areas related to exposure among terrestrial and semi-terrestrial organisms that warrant additional research. - Both biotic and abiotic factors determine chemical exposure for terrestrial vertebrates

  6. Radioactive contamination in imported foods

    International Nuclear Information System (INIS)

    Kan, Kimiko; Maki, Toshio; Nagayama, Toshihiro; Hashimoto, Hideki; Kawai, Yuka; Kobayashi, Maki; Shioda, Hiroko; Nishima, Taichiro

    1990-01-01

    On April 26, 1986, explosion occurred in Chernobyl nuclear power station in USSR, and radioactivity contamination was brought about in almost all countries in the world. In European countries, crops were contaminated directly with radioactive fallout to high concentration. Also in Japan, after one week the radioactivity higher than usual was detected in environment, and also in vegetables, milk, tea leaves and others. Thereafter, in order to cope with the import of contaminated foods, inspection and watch system was strengthened by deciding the interim limit of radioactive concentration. However the cases of exceeding the interim limit were often reported. In order to remove the harmful foods due to radioactive contamination and to meet the fear of consumers, the authors measured the radioactive concentration in foods distributed in Tokyo and investigated the actual state of contamination. The samples were 920 imported foods. The experimental method, the preparation of samples, the method of analysis and the results are reported. The samples in which the radioactive concentration exceeding 50 Bq/kg was detected were 25 cases. The food having the high frequency of detection was flavors. (K.I.)

  7. Processing plutonium-contaminated soild for volume reduction using the segmented gate system

    International Nuclear Information System (INIS)

    Moroney, K.S.; Moroney, J.D.; Turney, J.M.; Doane, R.W.

    1994-01-01

    TMA/Eberline has developed and demonstrated an effective method for removing mixed plutonium and americium contamination from a coral soil matrix at the Defense Nuclear Agency's Johnston Atoll site. TMA's onsite soil processing for volume reduction is ongoing at a rate of over 2000 metric tons per week. The system uses arrays of sensitive radiation detectors coupled with sophisticated computer software developed by Eberline Instrument Corporation. The proprietary software controls four soil sorting units operating in parallel that utilize TMA's unique Segmented Gate System technology to remove radiologically contaminated soil from a moving supply on conveyor belts. Clean soil is released for use elsewhere on the island. Contaminated soil is diverted to either a metal drum for collecting higher activity open-quotes hotclose quotes particles (>5000 Becquerels), or to a supplementary soil washing process designed to remove finely divided particles of dispersed low level contamination. Site contamination limits specify maximum dispersed radioactivity of no more than 500 Becquerels per kilogram of soil averaged over no more than 0.1 cubic meter. Results of soil processing at this site have been excellent. After processing over 50,000 metric tons, the volume of contaminated material that would have required expensive special handling, packaging, and disposal as radioactive waste has been successfully reduced by over 98 percent. By mid-January 1994, nearly three million kiloBecquerels of plutonium/americium contamination had been physically separated from the contaminated feed by TMA's Segmented Gate System, and quality control sampling showed no radioactivity above release criteria in the open-quotes cleanclose quotes soil pile

  8. Contamination monitoring in radiation protection activities in Myanmar

    Energy Technology Data Exchange (ETDEWEB)

    Thin, K T; Htoon, S [Yangon Univ. (Myanmar). Dept. of Physics

    1997-06-01

    The radioactive contamination in rainwater, seawater, air, milk powder and other eatables were measured with low level counter assembly. The measured activities are found to be very low and well within the maximum permissible level. (author)

  9. Discontinuity of maximum entropy inference and quantum phase transitions

    International Nuclear Information System (INIS)

    Chen, Jianxin; Ji, Zhengfeng; Yu, Nengkun; Zeng, Bei; Li, Chi-Kwong; Poon, Yiu-Tung; Shen, Yi; Zhou, Duanlu

    2015-01-01

    In this paper, we discuss the connection between two genuinely quantum phenomena—the discontinuity of quantum maximum entropy inference and quantum phase transitions at zero temperature. It is shown that the discontinuity of the maximum entropy inference of local observable measurements signals the non-local type of transitions, where local density matrices of the ground state change smoothly at the transition point. We then propose to use the quantum conditional mutual information of the ground state as an indicator to detect the discontinuity and the non-local type of quantum phase transitions in the thermodynamic limit. (paper)

  10. Efficiency of autonomous soft nanomachines at maximum power.

    Science.gov (United States)

    Seifert, Udo

    2011-01-14

    We consider nanosized artificial or biological machines working in steady state enforced by imposing nonequilibrium concentrations of solutes or by applying external forces, torques, or electric fields. For unicyclic and strongly coupled multicyclic machines, efficiency at maximum power is not bounded by the linear response value 1/2. For strong driving, it can even approach the thermodynamic limit 1. Quite generally, such machines fall into three different classes characterized, respectively, as "strong and efficient," "strong and inefficient," and "balanced." For weakly coupled multicyclic machines, efficiency at maximum power has lost any universality even in the linear response regime.

  11. Maximum power point tracker based on fuzzy logic

    International Nuclear Information System (INIS)

    Daoud, A.; Midoun, A.

    2006-01-01

    The solar energy is used as power source in photovoltaic power systems and the need for an intelligent power management system is important to obtain the maximum power from the limited solar panels. With the changing of the sun illumination due to variation of angle of incidence of sun radiation and of the temperature of the panels, Maximum Power Point Tracker (MPPT) enables optimization of solar power generation. The MPPT is a sub-system designed to extract the maximum power from a power source. In the case of solar panels power source. the maximum power point varies as a result of changes in its electrical characteristics which in turn are functions of radiation dose, temperature, ageing and other effects. The MPPT maximum the power output from panels for a given set of conditions by detecting the best working point of the power characteristic and then controls the current through the panels or the voltage across them. Many MPPT methods have been reported in literature. These techniques of MPPT can be classified into three main categories that include: lookup table methods, hill climbing methods and computational methods. The techniques vary according to the degree of sophistication, processing time and memory requirements. The perturbation and observation algorithm (hill climbing technique) is commonly used due to its ease of implementation, and relative tracking efficiency. However, it has been shown that when the insolation changes rapidly, the perturbation and observation method is slow to track the maximum power point. In recent years, the fuzzy controllers are used for maximum power point tracking. This method only requires the linguistic control rules for maximum power point, the mathematical model is not required and therefore the implementation of this control method is easy to real control system. In this paper, we we present a simple robust MPPT using fuzzy set theory where the hardware consists of the microchip's microcontroller unit control card and

  12. Environmental contaminants of emerging concern in seafood - European database on contaminant levels

    DEFF Research Database (Denmark)

    Vandermeersch, Griet; Lourenço, Helena Maria; Alvarez-Muñoz, Diana

    2015-01-01

    Marine pollution gives rise to concern not only about the environment itself but also about the impact on food safety and consequently on public health. European authorities and consumers have therefore become increasingly worried about the transfer of contaminants from the marine environment...... to seafood.So-called "contaminants of emerging concern" are chemical substances for which no maximum levels have been laid down in EU legislation, or substances for which maximum levels have been provided but which require revision. Adequate information on their presence in seafood is often lacking and thus...... potential risks cannot be excluded. Assessment of food safety issues related to these contaminants has thus become urgent and imperative. A database (www.ecsafeseafooddbase.eu), containing available information on the levels of contaminants of emerging concern in seafood and providing the most recent data...

  13. 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)

  14. Desorption and bioremediation of hydrocarbon contaminated soils

    International Nuclear Information System (INIS)

    Gray, M.R.

    1998-01-01

    A study was conducted in which the extent and pattern of contaminant biodegradation during bioremediation of four industrially-contaminated soils were examined to determine which factors control the ultimate extent of biodegradation and which limit the success of biological treatment. It was noted that although bioremediation is inexpensive and has low environmental impact, it often fails to completely remove the hydrocarbons in soils because of the complex interactions between contaminants, the soil environment, and the active microorganisms. In this study, the competency of the microorganisms in the soil to degrade the contaminants was examined. The equilibrium partitioning of the contaminants between the soil and the aqueous phase was also examined along with the transport of contaminants out of soil particles. The role of diffusion of compounds in the soil and the importance of direct contact between microorganisms and the hydrocarbons was determined. Methods for selecting suitable sites for biological treatment were also described

  15. Harvesting contaminants from liquid

    Science.gov (United States)

    Simpson, John T.; Hunter, Scott R.

    2016-05-31

    Disclosed are examples of apparatuses for evaporative purification of a contaminated liquid. In each example, there is a vessel for storing the contaminated fluid. The vessel includes a surface coated with a layer of superhydrophobic material and the surface is at least partially in contact with the contaminated liquid. The contaminants do not adhere to the surface as the purified liquid evaporates, thus allowing the contaminants to be harvested.

  16. Revealing the Maximum Strength in Nanotwinned Copper

    DEFF Research Database (Denmark)

    Lu, L.; Chen, X.; Huang, Xiaoxu

    2009-01-01

    boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...

  17. Modelling maximum canopy conductance and transpiration in ...

    African Journals Online (AJOL)

    There is much current interest in predicting the maximum amount of water that can be transpired by Eucalyptus trees. It is possible that industrial waste water may be applied as irrigation water to eucalypts and it is important to predict the maximum transpiration rates of these plantations in an attempt to dispose of this ...

  18. Mental contamination: The effects of religiosity.

    Science.gov (United States)

    Bilekli, Ilgun; Inozu, Mujgan

    2018-03-01

    Mental contamination, which occurs in the absence of contact with a contaminant, has a moral element. Previous studies evoked feelings of mental contamination via listening to a scenario, which described a non-consensual kiss. Since mental contamination has a moral element, we tested the effects of the level of religiosity on feelings of mental contamination and related variables in an experimental design. Female undergraduates of high religiosity (n = 48) and low religiosity (n = 44) were randomly assigned to listen to one of two audio recordings involving a consensual or non-consensual kiss from a man described as moral. Mental contamination feelings were evoked successfully in both groups. Effects of scenario condition and religiosity level were seen in mental contamination and related negative feelings. Participants who imagined a non-consensual kiss reported greatest feelings of mental contamination, and internal and external negative feelings. More importantly, high religiosity resulted in greater feelings of mental contamination, internal negative feelings, as well as urges to wash and actual washing behaviors. The current study was conducted on non-clinical Muslim females. This limits the generalization of the findings to the wider population. Mental contamination and related feelings can be seen in different forms at different levels of religiosity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Skin dose estimation due to a contamination by a radionuclide β emitter: are doses equivalent good estimator of protection quantities?

    International Nuclear Information System (INIS)

    Bourgois, L.

    2011-01-01

    When handling radioactive β emitters, measurements in terms of personal dose equivalents H p (0.07) are used to estimate the equivalent dose limit to skin or extremities given by regulations. First of all, analytical expressions for individual dose equivalents H p (0.07) and equivalent doses to the extremities H skin are given for a point source and for contamination with a radionuclide β emitter. Second of all, operational quantities and protection quantities are compared. It is shown that in this case the operational quantities significantly overstate the protection quantities. For a skin contamination the ratio between operational quantities and protection quantities is 2 for a maximum β energy of 3 MeV and 90 for a maximum β energy of 150 keV. (author)

  20. Patterns of radiocesium contamination in eggs of free-ranging wood ducks

    International Nuclear Information System (INIS)

    Kennamer, R.A.; McCreedy, C.D.; Brisbin, I.L. Jr.

    1993-01-01

    Studies of biological consequences of nuclear industrial contaminants in the environment increase in importance as the potential for exposure of wildlife populations rises. Thus, we examined levels of radiocesium (cesium-137) contamination in wood duck eggs from a Department of Energy nuclear facility in South Carolina during 1990. Radiocesium levels in individual eggs from 5 locations on the site ranged from below detectable concentrations to a maximum of 2.21 Bq/g wet mass. Eggs from an abandoned reactor cooling reservoir contained the greatest burdens; mean egg concentrations there were more than an order of magnitude higher than those from other locations studied. Eggs from a second radionuclide releases, all contained similar low radiocesium levels that were, on average, below detection limits. Variation in radiocesium concentrations of eggs from the most contaminated cooling reservoir was partitioned into within- and among-clutch variation. Approximately 33% of the variation in radiocesium content occurred among eggs laid by the same female, and may have resulted because females fed in both contaminated and uncontaminated habitats during egg formation. Radiation dose rates to developing wood duck embryos, resulting from internal and external sources examined in this study, were below those expected to affect hatchability or any other aspect of the breeding biology of these birds. Wood ducks and their eggs may be useful as bioindicators of radiocesium uptake, but we caution that local foraging patterns could cause variation in contaminant deposition within clutches. 45 refs., 1 fig., 2 tabs

  1. Contamination monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Alamares, A L [Philippine Nuclear Research Inst., Diliman, Quezon City (Philippines)

    1997-06-01

    By virture of Republic Act 2067, as amended the Philippine Atomic Energy Commission (PAEC), now renamed Philippine Nuclear Research Institute (PNRI) is the government agency charged with the regulations and control of radioactive materials in the Philippines. The protection against the hazards of non-ionizing radiation is being monitored by the Radiological Health Service (RHS) of the Department of Health pursuant to the provision of Presidental Decree 480. The RHS issues licenses for possession, handling, and use of x-ray machines and equipment, both industrial and medical, and provide radiation protection training to x-ray technologists and technicians. As part of its regulatory function, the PNRI is charged with the responsibility of assuring that the radiation workers and the public are protected from the hazards associated with the possession, handling, production, manufacturing, and the use of radioactive materials and atomic energy facilities in the Philippines. The protection of radiation workers from the hazards of ionizing radiation has always been a primary concern of PNRI and by limiting the exposure of radiation workers, the risk to population is kept to within acceptable level. In this paper, the following items are described: radiation protection program, radiation protection services, radiation control, and problems encountered/recommendation. (G.K.)

  2. Environmental contamination

    International Nuclear Information System (INIS)

    Parra Cardeno, William

    2000-01-01

    The association among hypersensibility to the inhaled allergens and the asthma in children, it is recognized. There is enough evidence about the nature of the exposed allergen and the immune inflammatory answer of the lung; sustained with a direct relationship among the exhibition to these allergens and the asthma. This association becomes evident in the children, until after the three years of age, what suggests that other factors have bigger importance in the precipitation of the sibilance in the childhood and the early childhood. This answer is limited those children that develop answer of antibodies IgE. Every year, in the world, figures of more morbid-mortality are reported for asthma, what could be explained by the increase in the exhibition to the allergens, and it is probable that the increase of the heat and the humidity in our houses improve the environmental conditions significantly for the growth of the acarus. The children have also increased the permanency in the houses, exposed to these pollutants, due to diverse attractions like the television, the Nintendo and games in the home. The paper includes some intra-domiciliary allergens

  3. Stationary neutrino radiation transport by maximum entropy closure

    International Nuclear Information System (INIS)

    Bludman, S.A.

    1994-11-01

    The authors obtain the angular distributions that maximize the entropy functional for Maxwell-Boltzmann (classical), Bose-Einstein, and Fermi-Dirac radiation. In the low and high occupancy limits, the maximum entropy closure is bounded by previously known variable Eddington factors that depend only on the flux. For intermediate occupancy, the maximum entropy closure depends on both the occupation density and the flux. The Fermi-Dirac maximum entropy variable Eddington factor shows a scale invariance, which leads to a simple, exact analytic closure for fermions. This two-dimensional variable Eddington factor gives results that agree well with exact (Monte Carlo) neutrino transport calculations out of a collapse residue during early phases of hydrostatic neutron star formation

  4. Considerations on the establishment of maximum permissible exposure of man

    International Nuclear Information System (INIS)

    Jacobi, W.

    1974-01-01

    An attempt is made in the information lecture to give a quantitative analysis of the somatic radiation risk and to illustrate a concept to fix dose limiting values. Of primary importance is the limiting values. Of primary importance is the limiting value of the radiation exposure to the whole population. By consequential application of the risk concept, the following points are considered: 1) Definition of the risk for radiation late damages (cancer, leukemia); 2) relationship between radiation dose and thus caused radiation risk; 3) radiation risk and the dose limiting values at the time; 4) criteria for the maximum acceptable radiation risk; 5) limiting value which can be expected at the time. (HP/LH) [de

  5. Limitations of Boltzmann's principle

    International Nuclear Information System (INIS)

    Lavenda, B.H.

    1995-01-01

    The usual form of Boltzmann's principle assures that maximum entropy, or entropy reduction, occurs with maximum probability, implying a unimodal distribution. Boltzmann's principle cannot be applied to nonunimodal distributions, like the arcsine law, because the entropy may be concave only over a limited portion of the interval. The method of subordination shows that the arcsine distribution corresponds to a process with a single degree of freedom, thereby confirming the invalidation of Boltzmann's principle. The fractalization of time leads to a new distribution in which arcsine and Cauchy distributions can coexist simultaneously for nonintegral degrees of freedom between √2 and 2

  6. Scientific substantination of maximum allowable concentration of fluopicolide in water

    Directory of Open Access Journals (Sweden)

    Pelo I.М.

    2014-03-01

    Full Text Available In order to substantiate fluopicolide maximum allowable concentration in the water of water reservoirs the research was carried out. Methods of study: laboratory hygienic experiment using organoleptic and sanitary-chemical, sanitary-toxicological, sanitary-microbiological and mathematical methods. The results of fluopicolide influence on organoleptic properties of water, sanitary regimen of reservoirs for household purposes were given and its subthreshold concentration in water by sanitary and toxicological hazard index was calculated. The threshold concentration of the substance by the main hazard criteria was established, the maximum allowable concentration in water was substantiated. The studies led to the following conclusions: fluopicolide threshold concentration in water by organoleptic hazard index (limiting criterion – the smell – 0.15 mg/dm3, general sanitary hazard index (limiting criteria – impact on the number of saprophytic microflora, biochemical oxygen demand and nitrification – 0.015 mg/dm3, the maximum noneffective concentration – 0.14 mg/dm3, the maximum allowable concentration - 0.015 mg/dm3.

  7. MXLKID: a maximum likelihood parameter identifier

    International Nuclear Information System (INIS)

    Gavel, D.T.

    1980-07-01

    MXLKID (MaXimum LiKelihood IDentifier) is a computer program designed to identify unknown parameters in a nonlinear dynamic system. Using noisy measurement data from the system, the maximum likelihood identifier computes a likelihood function (LF). Identification of system parameters is accomplished by maximizing the LF with respect to the parameters. The main body of this report briefly summarizes the maximum likelihood technique and gives instructions and examples for running the MXLKID program. MXLKID is implemented LRLTRAN on the CDC7600 computer at LLNL. A detailed mathematical description of the algorithm is given in the appendices. 24 figures, 6 tables

  8. Rapid determination of radionuclide activity concentrations in contaminated drinking water

    International Nuclear Information System (INIS)

    Medley, P.; Ryan, B.; Bollhofer, A.; Martin, P.; International Atomic Energy Agency, Vienna

    2007-01-01

    As a result of an incident at the Ranger Uranium mine in which drinking water was contaminated with process water, it was necessary to perform quick analysis for naturally occurring uranium and thorium series radionuclide activity concentrations, including 226Ra, 210Pb, 210Po, U and Th isotopes. The methods which were subsequently used are presented here. The techniques used were high-resolution gamma spectrometry, Inductively Coupled Plasma Mass Spectrometry (ICPMS) and high-resolution alpha spectrometry. Routine methods were modified to allow for rapid analyses on priority samples in 1-2 days, with some results for highest priority samples available in less than 1 day. Comparison of initial results obtained through standard procedures, is discussed. An emphasis is placed on high-resolution alpha spectrometry of major alpha-emitting nuclides, specifically 226Ra, 230Th and 238U. The range of uranium concentrations in the samples investigated was from background levels to 6.6ppm. Implications for radiological dose assessment in contamination incidents involving process water are presented. The worst-case scenario for the incident at Ranger Uranium Mine indicates that the maximum committed effective dose to workers was well below the ICRP limit for worker-related dose and below the dose limit for a member of the public, with 230Th being the highest contributor

  9. Environmental contaminants of emerging concern in seafood – European database on contaminant levels

    International Nuclear Information System (INIS)

    Vandermeersch, Griet; Lourenço, Helena Maria; Alvarez-Muñoz, Diana; Cunha, Sara; Diogène, Jorge; Cano-Sancho, German; Sloth, Jens J.; Kwadijk, Christiaan; Barcelo, Damia; Allegaert, Wim; Bekaert, Karen; Fernandes, José Oliveira; Marques, Antonio

    2015-01-01

    Marine pollution gives rise to concern not only about the environment itself but also about the impact on food safety and consequently on public health. European authorities and consumers have therefore become increasingly worried about the transfer of contaminants from the marine environment to seafood. So-called “contaminants of emerging concern” are chemical substances for which no maximum levels have been laid down in EU legislation, or substances for which maximum levels have been provided but which require revision. Adequate information on their presence in seafood is often lacking and thus potential risks cannot be excluded. Assessment of food safety issues related to these contaminants has thus become urgent and imperative. A database ( (www.ecsafeseafooddbase.eu)), containing available information on the levels of contaminants of emerging concern in seafood and providing the most recent data to scientists and regulatory authorities, was developed. The present paper reviews a selection of contaminants of emerging concern in seafood including toxic elements, endocrine disruptors, brominated flame retardants, pharmaceuticals and personal care products, polycyclic aromatic hydrocarbons and derivatives, microplastics and marine toxins. Current status on the knowledge of human exposure, toxicity and legislation are briefly presented and the outcome from scientific publications reporting on the levels of these compounds in seafood is presented and discussed. - Highlights: • Development of a European database regarding contaminants of emerging concern. • Current status on knowledge of human exposure, toxicity and legislation. • Review on the occurrence of contaminants of emerging concern in seafood.

  10. Environmental contaminants of emerging concern in seafood – European database on contaminant levels

    Energy Technology Data Exchange (ETDEWEB)

    Vandermeersch, Griet, E-mail: griet.vandermeersch@ilvo.vlaanderen.be [Institute for Agricultural and Fisheries Research (ILVO), Animal Sciences Unit – Fisheries, Ankerstraat 1, 8400 Oostende (Belgium); Lourenço, Helena Maria [Division of Aquaculture and Upgrading (DivAV), Portuguese Institute for the Sea and Atmosphere (IPMA), Lisboa (Portugal); Alvarez-Muñoz, Diana [Catalan Institute for Water Research (ICRA), Girona (Spain); Cunha, Sara [LAQV-REQUIMTE, Laboratory of Bromatology and Hydrology, Faculty of Pharmacy, University of Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto (Portugal); Diogène, Jorge [Institute of Research and Technology in Food and Agriculture (IRTA), Sant Carles de la Ràpita (Spain); Cano-Sancho, German [Laboratory of Toxicology and Environmental Health, School of Medicine, Rovirai Virgili University (URV), Reus (Spain); Sloth, Jens J. [National Food Institute, Technical University of Denmark (DTU Food), Søborg (Denmark); Kwadijk, Christiaan [Institute for Marine Resources and Ecosystem Studies (IMARES), Wageningen University and Research Center, Ijmuiden (Netherlands); Barcelo, Damia [Catalan Institute for Water Research (ICRA), Girona (Spain); Water and Soil Quality Research Group, Department of Environmental Chemistry, IDAEA-CSIC, Barcelona (Spain); Allegaert, Wim; Bekaert, Karen [Institute for Agricultural and Fisheries Research (ILVO), Animal Sciences Unit – Fisheries, Ankerstraat 1, 8400 Oostende (Belgium); Fernandes, José Oliveira [LAQV-REQUIMTE, Laboratory of Bromatology and Hydrology, Faculty of Pharmacy, University of Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto (Portugal); Marques, Antonio [Division of Aquaculture and Upgrading (DivAV), Portuguese Institute for the Sea and Atmosphere (IPMA), Lisboa (Portugal); and others

    2015-11-15

    Marine pollution gives rise to concern not only about the environment itself but also about the impact on food safety and consequently on public health. European authorities and consumers have therefore become increasingly worried about the transfer of contaminants from the marine environment to seafood. So-called “contaminants of emerging concern” are chemical substances for which no maximum levels have been laid down in EU legislation, or substances for which maximum levels have been provided but which require revision. Adequate information on their presence in seafood is often lacking and thus potential risks cannot be excluded. Assessment of food safety issues related to these contaminants has thus become urgent and imperative. A database ( (www.ecsafeseafooddbase.eu)), containing available information on the levels of contaminants of emerging concern in seafood and providing the most recent data to scientists and regulatory authorities, was developed. The present paper reviews a selection of contaminants of emerging concern in seafood including toxic elements, endocrine disruptors, brominated flame retardants, pharmaceuticals and personal care products, polycyclic aromatic hydrocarbons and derivatives, microplastics and marine toxins. Current status on the knowledge of human exposure, toxicity and legislation are briefly presented and the outcome from scientific publications reporting on the levels of these compounds in seafood is presented and discussed. - Highlights: • Development of a European database regarding contaminants of emerging concern. • Current status on knowledge of human exposure, toxicity and legislation. • Review on the occurrence of contaminants of emerging concern in seafood.

  11. Maximum phytoplankton concentrations in the sea

    DEFF Research Database (Denmark)

    Jackson, G.A.; Kiørboe, Thomas

    2008-01-01

    A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collect...

  12. FY 1999 cold demonstration of the Multi-Point Injection (MPI) process for stabilizing contaminated sludge in buried horizontal tanks with limited access at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Kauschinger, J.L.; Lewis, B.E.; Spence, R.D.

    2000-01-01

    A major problem faced by the U.S. Department of Energy is the remediation of buried tank waste. Exhumation of the sludge is currently the preferred remediation method. However, exhumation does not typically remove all the contaminated material from the tank. The best management practices for in-tank treatment of wastes require an integrated approach to develop appropriate treatment agents that can be safely delivered and uniformly mixed with the sludge. Ground Environmental Services, Inc., has developed and demonstrated a remotely controlled, high-velocity, jet-delivery system, which is termed Multi-Point-Injection (MPItrademark). This robust jet-delivery system has been used to create homogeneous monoliths containing shallow-buried miscellaneous waste in trenches [fiscal year (FY) 1995] and surrogate sludge in a cylindrical test tank (FY 1998). During the FY 1998 demonstration, the MPI process was able to successfully form a 32-ton uniform monolith in about 8 min. Analytical data indicated that 10 tons of a zeolite-type physical surrogate were uniformly mixed within the 40-inch-thick monolith without lifting the MPI jetting tools off the tank floor. Over 1,000 lb of cohesive surrogates, with consistencies of Gunite and Associated Tanks (GAATs) TH-4 and Hanford tank sludges, were easily mixed into the monolith without exceeding a core temperature of 100 F during curing

  13. The calculation of maximum permissible exposure levels for laser radiation

    International Nuclear Information System (INIS)

    Tozer, B.A.

    1979-01-01

    The maximum permissible exposure data of the revised standard BS 4803 are presented as a set of decision charts which ensure that the user automatically takes into account such details as pulse length and pulse pattern, limiting angular subtense, combinations of multiple wavelength and/or multiple pulse lengths, etc. The two decision charts given are for the calculation of radiation hazards to skin and eye respectively. (author)

  14. Investigation on maximum transition temperature of phonon mediated superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Fusui, L; Yi, S; Yinlong, S [Physics Department, Beijing University (CN)

    1989-05-01

    Three model effective phonon spectra are proposed to get plots of {ital T}{sub {ital c}}-{omega} adn {lambda}-{omega}. It can be concluded that there is no maximum limit of {ital T}{sub {ital c}} in phonon mediated superconductivity for reasonable values of {lambda}. The importance of high frequency LO phonon is also emphasized. Some discussions on high {ital T}{sub {ital c}} are given.

  15. The Value and limitations of various approaches to the monitoring of water quality for freshwater fish

    National Research Council Canada - National Science Library

    1978-01-01

    Concomitant with the general desire to protect freshwater fisheries has been an expansion of research into their water quality requirements and, for important contaminants, the maximum concentrations...

  16. Maximum-Likelihood Detection Of Noncoherent CPM

    Science.gov (United States)

    Divsalar, Dariush; Simon, Marvin K.

    1993-01-01

    Simplified detectors proposed for use in maximum-likelihood-sequence detection of symbols in alphabet of size M transmitted by uncoded, full-response continuous phase modulation over radio channel with additive white Gaussian noise. Structures of receivers derived from particular interpretation of maximum-likelihood metrics. Receivers include front ends, structures of which depends only on M, analogous to those in receivers of coherent CPM. Parts of receivers following front ends have structures, complexity of which would depend on N.

  17. Status on contamination monitoring in China

    Energy Technology Data Exchange (ETDEWEB)

    Quanlu, Gou [China Institute for Radiation Protection, Taiyuan (China)

    1997-06-01

    The air contaminated by radioactive materials in nuclear enterprises and radioactive workplaces and forming radioactive aerosol and the leakage of radioactive materials in operation cause internal exposure damage in workers. It is necessary and important to monitor air and surface contaminations for the health of public and workers, and for protecting environment. At present, many institutes engage in the studies on surface contamination monitoring in China, and the government has formulated the control limits of surface contamination in the Regulations of Radiation Protection. The monitors for surface contamination monitoring are almost home-made. The methods being used often are smear test and placing surface sample test. Scintillation counters, semiconductor detectors and G-M counters have been used for detecting alpha surface contamination. Plastic scintillator meters and thin wall/window G-M counters are used for beta surface contamination. Special detectors have been designed for monitoring low energy nuclides. The status of airborne contamination monitoring in China is reported. As the studies for future, the development of the surface contamination monitor for low energy beta nuclides, especially H-3, the monitoring methods for the special shapes of surfaces, the technology of decontamination and the calibration method and device for on-line radioactive aerosol continuous monitors are taken up. (K.I.)

  18. Center for Contaminated Sediments

    Data.gov (United States)

    Federal Laboratory Consortium — The U.S. Army Corps of Engineers Center for Contaminated Sediments serves as a clearinghouse for technology and expertise concerned with contaminated sediments. The...

  19. Contaminated Sites in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Sites contaminated by hazardous materials or wastes. These sites are those administered by the Contaminated Sites Section of Iowa DNR. Many are sites which are...

  20. Lab-scale investigation on remediation of diesel-contaminated aquifer using microwave energy.

    Science.gov (United States)

    Falciglia, Pietro P; Maddalena, Riccardo; Mancuso, Giuseppe; Messina, Valeria; Vagliasindi, Federico G A

    2016-02-01

    Aquifer contamination with diesel fuel is a worldwide environmental problem, and related available remediation technologies may not be adequately efficient, especially for the simultaneous treatment of both solid and water phases. In this paper, a lab-scale 2.45 GHz microwave (MW) treatment of an artificially diesel-contaminated aquifer was applied to investigate the effects of operating power (160, 350 and 500 W) and time on temperature profiles and contaminant removal from both solid and water phases. Results suggest that in diesel-contaminated aquifer MW remediation, power significantly influences the final reachable temperature and, consequently, contaminant removal kinetics. A maximum temperature of about 120 °C was reached at 500 W. Observed temperature values depended on the simultaneous irradiation of both aquifer grains and groundwater. In this case, solid phase heating is limited by the maximum temperature that interstitial water can reach before evaporation. A minimal residual diesel concentration of about 100 mg kg(-1) or 100 mg L(-1) was achieved by applying a power of 500 W for a time of 60 min for the solid or water phase, respectively. Measured residual TPH fractions showed that MW heating resulted in preferential effects of the removal of different TPH molecular weight fractions and that the evaporation-stripping phenomena plays a major role in final contaminant removal processes. The power low kinetic equation shows an excellent fit (r(2) > 0.993) with the solid phase residual concentration observed for all the powers investigated. A maximum diesel removal of 88 or 80% was observed for the MW treatment of the solid or water phase, respectively, highlighting the possibility to successfully and simultaneously remediate both the aquifer phases. Consequently, MW, compared to other biological or chemical-physical treatments, appears to be a better choice for the fast remediation of diesel-contaminated aquifers. Copyright © 2015 Elsevier

  1. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  2. Restoration of contaminated soils

    International Nuclear Information System (INIS)

    Miranda J, Jose Eduardo

    2009-01-01

    A great variety of techniques are used for the restoration of contaminated soils. The contamination is present by both organic and inorganic pollutants. Environmental conditions and soil characteristics should take into account in order to implement a remedial technique. The bioremediation technologies are showed as help to remove a variety of soil contaminants. (author) [es

  3. A method for determining allowable residual contamination levels of radionuclide mixtures in soil

    International Nuclear Information System (INIS)

    Napier, B.A.

    1982-05-01

    An important consideration in the disposal of radioactive wastes, and consequently in the preparation of plans for remedial actions at contaminated sites, is the amount of radioactive contamination that may be allowed to remain at any particular waste site. The allowable residual contamination level (ARCL) is dependent on the radiation dose limit imposed, the physical and environmental characteristics of the waste site, and the time at which exposure to the wastes is assumed to occur. The steps in generating an ARCL are generally as follows: (1) develop plausible, credible site-specific exposure scenario; (2) calculate maximum annual radiation doses to an individual for each radionuclide based on the existing physical characteristics of the waste site and the site-specific exposure scenario; (3) calculate the ARCL for the dose limit desired, including all radionuclides present, uncorrected for site cleanup or barrier considerations; and (4) apply any corrections for proposed cleanup activity or addition of barriers to waste migration or uptake to obtain the ARCL applicable to the proposed action. Use of this method allows appropriate application of resources to achieve uniform compliance with a single regulatory standard, i.e., a radiation dose rate limit. Application and modification of the ARCL method requires appropriate models of the environmental transport and fate of radionuclides. Example calculations are given for several specific waste forms and waste site types in order to demonstrate the technique and generate comparisons with other approaches

  4. Transformation of primary contaminant in the environment of 30-km planned NPP zone

    International Nuclear Information System (INIS)

    Pavlovich, E.L.; Zhigunova, L.N.; Makovskaya, N.A.

    2011-01-01

    As a result of work fulfillment ambient nitrogen-bearing level of primary contaminant and oncogenic N-nitrosodimethy-lamine as well as human biologic fluid were measured. It was registered, that there are primary contaminants which do not exceed maximum allowable concentration in external entities. However, concentration of secondary contaminant of N-nitrosodimethylamine in atmospheric air exceeds in up to 3 times agreed value of maximum allowable concentration. (authors).

  5. Density limits in Tokamaks

    International Nuclear Information System (INIS)

    Tendler, M.

    1984-06-01

    The energy loss from a tokamak plasma due to neutral hydrogen radiation and recycling is of great importance for the energy balance at the periphery. It is shown that the requirement for thermal equilibrium implies a constraint on the maximum attainable edge density. The relation to other density limits is discussed. The average plasma density is shown to be a strong function of the refuelling deposition profile. (author)

  6. Fusarium graminearum in Stored Wheat: Use of CO2 Production to Quantify Dry Matter Losses and Relate This to Relative Risks of Zearalenone Contamination under Interacting Environmental Conditions

    Science.gov (United States)

    Kiaitsi, Elsa; Magan, Naresh

    2018-01-01

    Zearalenone (ZEN) contamination from Fusarium graminearum colonization is particularly important in food and feed wheat, especially during post-harvest storage with legislative limits for both food and feed grain. Indicators of the relative risk from exceeding these limits would be useful. We examined the effect of different water activities (aw; 0.95–0.90) and temperature (10–25 °C) in naturally contaminated and irradiated wheat grain, both inoculated with F. graminearum and stored for 15 days on (a) respiration rate; (b) dry matter losses (DML); (c) ZEN production and (d) relationship between DML and ZEN contamination relative to the EU legislative limits. Gas Chromatography was used to measure the temporal respiration rates and the total accumulated CO2 production. There was an increase in temporal CO2 production rates in wetter and warmer conditions in all treatments, with the highest respiration in the 25 °C × 0.95 aw treatments + F. graminearum inoculation. This was reflected in the total accumulated CO2 in the treatments. The maximum DMLs were in the 0.95 aw/20–25 °C treatments and at 10 °C/0.95 aw. The DMLs were modelled to produce contour maps of the environmental conditions resulting in maximum/minimum losses. Contamination with ZEN/ZEN-related compounds were quantified. Maximum production was at 25 °C/0.95–0.93 aw and 20 °C/0.95 aw. ZEN contamination levels plotted against DMLs for all the treatments showed that at ca. 1.0% DML, the risk was high. This type of data is important in building a database for the development of a post-harvest decision support system for relative risks of different mycotoxins. PMID:29462982

  7. Fusarium graminearum in Stored Wheat: Use of CO₂ Production to Quantify Dry Matter Losses and Relate This to Relative Risks of Zearalenone Contamination under Interacting Environmental Conditions.

    Science.gov (United States)

    Garcia-Cela, Esther; Kiaitsi, Elsa; Sulyok, Michael; Medina, Angel; Magan, Naresh

    2018-02-17

    Zearalenone (ZEN) contamination from Fusarium graminearum colonization is particularly important in food and feed wheat, especially during post-harvest storage with legislative limits for both food and feed grain. Indicators of the relative risk from exceeding these limits would be useful. We examined the effect of different water activities (a w ; 0.95-0.90) and temperature (10-25 °C) in naturally contaminated and irradiated wheat grain, both inoculated with F. graminearum and stored for 15 days on (a) respiration rate; (b) dry matter losses (DML); (c) ZEN production and (d) relationship between DML and ZEN contamination relative to the EU legislative limits. Gas Chromatography was used to measure the temporal respiration rates and the total accumulated CO₂ production. There was an increase in temporal CO₂ production rates in wetter and warmer conditions in all treatments, with the highest respiration in the 25 °C × 0.95 a w treatments + F. graminearum inoculation. This was reflected in the total accumulated CO₂ in the treatments. The maximum DMLs were in the 0.95 a w /20-25 °C treatments and at 10 °C/0.95 a w . The DMLs were modelled to produce contour maps of the environmental conditions resulting in maximum/minimum losses. Contamination with ZEN/ZEN-related compounds were quantified. Maximum production was at 25 °C/0.95-0.93 a w and 20 °C/0.95 a w . ZEN contamination levels plotted against DMLs for all the treatments showed that at ca 1.0% DML, the risk was high. This type of data is important in building a database for the development of a post-harvest decision support system for relative risks of different mycotoxins.

  8. Quench limits

    International Nuclear Information System (INIS)

    Sapinski, M.

    2012-01-01

    With thirteen beam induced quenches and numerous Machine Development tests, the current knowledge of LHC magnets quench limits still contains a lot of unknowns. Various approaches to determine the quench limits are reviewed and results of the tests are presented. Attempt to reconstruct a coherent picture emerging from these results is taken. The available methods of computation of the quench levels are presented together with dedicated particle shower simulations which are necessary to understand the tests. The future experiments, needed to reach better understanding of quench limits as well as limits for the machine operation are investigated. The possible strategies to set BLM (Beam Loss Monitor) thresholds are discussed. (author)

  9. Maximum entropy analysis of EGRET data

    DEFF Research Database (Denmark)

    Pohl, M.; Strong, A.W.

    1997-01-01

    EGRET data are usually analysed on the basis of the Maximum-Likelihood method \\cite{ma96} in a search for point sources in excess to a model for the background radiation (e.g. \\cite{hu97}). This method depends strongly on the quality of the background model, and thus may have high systematic unce...... uncertainties in region of strong and uncertain background like the Galactic Center region. Here we show images of such regions obtained by the quantified Maximum-Entropy method. We also discuss a possible further use of MEM in the analysis of problematic regions of the sky....

  10. The Maximum Resource Bin Packing Problem

    DEFF Research Database (Denmark)

    Boyar, J.; Epstein, L.; Favrholdt, L.M.

    2006-01-01

    Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find...

  11. Shower maximum detector for SDC calorimetry

    International Nuclear Information System (INIS)

    Ernwein, J.

    1994-01-01

    A prototype for the SDC end-cap (EM) calorimeter complete with a pre-shower and a shower maximum detector was tested in beams of electrons and Π's at CERN by an SDC subsystem group. The prototype was manufactured from scintillator tiles and strips read out with 1 mm diameter wave-length shifting fibers. The design and construction of the shower maximum detector is described, and results of laboratory tests on light yield and performance of the scintillator-fiber system are given. Preliminary results on energy and position measurements with the shower max detector in the test beam are shown. (authors). 4 refs., 5 figs

  12. Topics in Bayesian statistics and maximum entropy

    International Nuclear Information System (INIS)

    Mutihac, R.; Cicuttin, A.; Cerdeira, A.; Stanciulescu, C.

    1998-12-01

    Notions of Bayesian decision theory and maximum entropy methods are reviewed with particular emphasis on probabilistic inference and Bayesian modeling. The axiomatic approach is considered as the best justification of Bayesian analysis and maximum entropy principle applied in natural sciences. Particular emphasis is put on solving the inverse problem in digital image restoration and Bayesian modeling of neural networks. Further topics addressed briefly include language modeling, neutron scattering, multiuser detection and channel equalization in digital communications, genetic information, and Bayesian court decision-making. (author)

  13. Density estimation by maximum quantum entropy

    International Nuclear Information System (INIS)

    Silver, R.N.; Wallstrom, T.; Martz, H.F.

    1993-01-01

    A new Bayesian method for non-parametric density estimation is proposed, based on a mathematical analogy to quantum statistical physics. The mathematical procedure is related to maximum entropy methods for inverse problems and image reconstruction. The information divergence enforces global smoothing toward default models, convexity, positivity, extensivity and normalization. The novel feature is the replacement of classical entropy by quantum entropy, so that local smoothing is enforced by constraints on differential operators. The linear response of the estimate is proportional to the covariance. The hyperparameters are estimated by type-II maximum likelihood (evidence). The method is demonstrated on textbook data sets

  14. On the maximum entropy distributions of inherently positive nuclear data

    Energy Technology Data Exchange (ETDEWEB)

    Taavitsainen, A., E-mail: aapo.taavitsainen@gmail.com; Vanhanen, R.

    2017-05-11

    The multivariate log-normal distribution is used by many authors and statistical uncertainty propagation programs for inherently positive quantities. Sometimes it is claimed that the log-normal distribution results from the maximum entropy principle, if only means, covariances and inherent positiveness of quantities are known or assumed to be known. In this article we show that this is not true. Assuming a constant prior distribution, the maximum entropy distribution is in fact a truncated multivariate normal distribution – whenever it exists. However, its practical application to multidimensional cases is hindered by lack of a method to compute its location and scale parameters from means and covariances. Therefore, regardless of its theoretical disadvantage, use of other distributions seems to be a practical necessity. - Highlights: • Statistical uncertainty propagation requires a sampling distribution. • The objective distribution of inherently positive quantities is determined. • The objectivity is based on the maximum entropy principle. • The maximum entropy distribution is the truncated normal distribution. • Applicability of log-normal or normal distribution approximation is limited.

  15. 40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

    Science.gov (United States)

    2010-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER...-228 Ion exchange, reverse osmosis, lime softening. Uranium Ion exchange, reverse osmosis, lime... osmosis. Beta particle and photon radioactivity Ion exchange, reverse osmosis. (ii) In addition, the...

  16. 40 CFR Appendix I to Part 257 - Maximum Contaminant Levels (MCLs)

    Science.gov (United States)

    2010-07-01

    ... Drinking Water Act Chemical CAS No. MCL -(mg/l) Arsenic 7440-38-2 0.05 Barium 7440-39-3 1.0 Benzene 71-343... 0.004 Lead 7439-92-1 0.05 Mercury 7439-97-6 0.002 Methoxychlor 72-43-5 0.1 Nitrate 10.0 Selenium...

  17. Research on maximum level noise contaminated of remote reference magnetotelluric measurements using synthesized data

    Science.gov (United States)

    Gang, Zhang; Fansong, Meng; Jianzhong, Wang; Mingtao, Ding

    2018-02-01

    Determining magnetotelluric impedance precisely and accurately is fundamental to valid inversion and geological interpretation. This study aims to determine the minimum value of signal-to-noise ratio (SNR) which maintains the effectiveness of remote reference technique. Results of standard time series simulation, addition of different Gaussian noises to obtain the different SNR time series, and analysis of the intermediate data, such as polarization direction, correlation coefficient, and impedance tensor, show that when the SNR value is larger than 23.5743, the polarization direction disorder at morphology and a smooth and accurate sounding carve value can be obtained. At this condition, the correlation coefficient value of nearly complete segments between the base and remote station is larger than 0.9, and impedance tensor Zxy presents only one aggregation, which meet the natural magnetotelluric signal characteristic.

  18. A 12-Month Study of Food Crops Contaminated by Heavy Metals, Lusaka, Zambia

    Science.gov (United States)

    Holden, J. A.; Malamud, B. D.; Chishala, B. H.; Kapungwe, E.; Volk, J.; Harpp, K. S.

    2009-04-01

    We investigate heavy-metal contamination of irrigation water used for urban agriculture and subsequent contamination of food crops in Chunga, NW Lusaka, the capital of Zambia. Inhabitants of the Chunga area rely on urban agriculture as both a major source of income and food. From August 2004 to July 2005, monthly samples of irrigation water used and edible portions of food crops were taken from a farmer's plot at Chunga. The food crops (cabbage, Chinese cabbage, pumpkin leaves, rape, sweet potato leaves and tomatoes) are grown using irrigation throughout the year. Irrigation water samples and digested food crop samples were analysed using ICP-MS at the Department of Geology, Colgate University, USA for Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Ba, Hg, Tl, Pb, and U. We find heavy-metal concentrations present in both irrigation water and food crop samples. Zambian sample concentrations were compared to Zambian and international legislative and guideline limits for concentrations of heavy metals in industrial effluent, heavy metals in irrigation water and heavy metals in foods. In irrigation water samples recommended national and/or international legislative limits for Al, Cr, Mn, Fe, Cu, Hg, Pb and U were exceeded. Limits for Hg were exceeded by up to 130 times. There were heavy-metal concentrations above recommended limits in food crops for Cr, Fe, Ni, Cu, Zn, Cd, Hg and Pb throughout the different food crops grown and throughout the year. In all 14 samples recommended limits for Cr, Fe and Hg were exceeded. Zambian legislated limits for food crops were exceeded by up to 16 times for Pb and 58 times for Hg. The results of this study show that heavy metal contamination is present in irrigation water used and food crops grown in urban agriculture in Chunga, Lusaka, Zambia. Recommended maximum limits for heavy metals in irrigation water and food are exceeded in some samples indicating there may be a risk to health.

  19. The maximum economic depth of groundwater abstraction for irrigation

    Science.gov (United States)

    Bierkens, M. F.; Van Beek, L. P.; de Graaf, I. E. M.; Gleeson, T. P.

    2017-12-01

    Over recent decades, groundwater has become increasingly important for agriculture. Irrigation accounts for 40% of the global food production and its importance is expected to grow further in the near future. Already, about 70% of the globally abstracted water is used for irrigation, and nearly half of that is pumped groundwater. In many irrigated areas where groundwater is the primary source of irrigation water, groundwater abstraction is larger than recharge and we see massive groundwater head decline in these areas. An important question then is: to what maximum depth can groundwater be pumped for it to be still economically recoverable? The objective of this study is therefore to create a global map of the maximum depth of economically recoverable groundwater when used for irrigation. The maximum economic depth is the maximum depth at which revenues are still larger than pumping costs or the maximum depth at which initial investments become too large compared to yearly revenues. To this end we set up a simple economic model where costs of well drilling and the energy costs of pumping, which are a function of well depth and static head depth respectively, are compared with the revenues obtained for the irrigated crops. Parameters for the cost sub-model are obtained from several US-based studies and applied to other countries based on GDP/capita as an index of labour costs. The revenue sub-model is based on gross irrigation water demand calculated with a global hydrological and water resources model, areal coverage of crop types from MIRCA2000 and FAO-based statistics on crop yield and market price. We applied our method to irrigated areas in the world overlying productive aquifers. Estimated maximum economic depths range between 50 and 500 m. Most important factors explaining the maximum economic depth are the dominant crop type in the area and whether or not initial investments in well infrastructure are limiting. In subsequent research, our estimates of

  20. Radiological Risk Assessment and Survey of Radioactive Contamination for Foodstuffs

    International Nuclear Information System (INIS)

    Lee, W.R.; Lee, C.W.; Choi, K.S.

    2007-11-01

    After the Chernobyl nuclear accident in 1986, a radiological dose assessment and a survey of a radioactive contamination for foodstuffs have been investigated by many countries such as EU, Japan, USA. In the case of Japan which is similar to our country for the imported regions of foodstuffs, there were some instances of the excess for regulation on the maximum permitted levels of radioactive contamination among some imported foodstuffs. Concerns about the radioactive contamination of foodstuffs are increased because of the recently special situation (Nuclear test of North Korea). The purpose of this study is a radiological dose assessment and a survey of a radioactive contamination for foodstuffs in order to reduce the probability of intake of contaminated foodstuffs. Analytical results of the collected samples are below MDA. In this project, the model of radiological dose assessment via the food chain was also developed and radiological dose assessment was conducted based on surveys results of a radioactive contamination for foodstuffs in the Korean open markets since 2002. The results of radiological dose assessment are far below international reference level. It shows that public radiation exposure via food chain is well controlled within the international guide level. However, the radioactive contamination research of imported foodstuffs should be continuous considering the special situation(nuclear test of North Korea). These results are used to manage the radioactive contamination of the imported foodstuffs and also amend the regulation on the maximum permitted levels of radioactive contamination of foodstuffs

  1. Potential evaluation of hydrogen peroxide for in-situ bioremediation of contaminated subsoils (chances, limitations, consequences). Final report; Untersuchung des Anwendungspotentials von Wasserstoffperoxid bei der biotechnologischen in-situ-Sanierung von kontaminierten Boeden (Moeglichkeiten, Grenzen, Folgen). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Barenschee, E R; Weppen, P; Mueller, B G; Deckwer, W D; Muennich, K; Collins, H J

    1992-06-01

    Intention of this investigation was the development of methods for microbiological in situ decontamination of hydrocarbon polluted subsoils as an alternative or completion of pump and treat techniques. The changes and limitations of H{sub 2}O{sub 2} as an oxygensource was investigated on soil filled fixed bed bioreactors. The aerobic biodegradation of mineraloil products is limited by the supply of oxygen up to a conversion of 70-80%. During this state the degradation rate depends strongly on the oxygen intake rate. The degree of oxygen consumption is close to the theoretical value with regard to total mineralization and build up to biomass. At conversions higher than 70-80% the degradation rate decreases sharply due to transition from 0- to C- limitation. First attempts to increase the degradation rate by increasing the bioavailability at this state were successful. The behaviour of H{sub 2}O{sub 2} during transportation in the subsoil depends strongly on biological and physical/chemical parameters. Little remobilization of heavy metals were observed at the transition from reduced to oxidized state. (orig.) With 28 refs., 11 tabs., 34 figs. [Deutsch] Vorhabens Ziel ist die Methodenentwicklung zur mikrobiologisch unterstuetzten in-situ Dekontamination kohlenwasserstoffverunreinigter Boeden als Alternative oder Ergaenzung von hydraulischen Massnahmen. Die Moeglichkeiten und Grenzen von H{sub 2}O{sub 2} als Sauerstofftraeger werden anhand von Laborstudien mit Bodenbioreaktoren dargestellt. Der aerobe Abbau von Mineraloelprodukten ist bis zu Umsaetzen von 70-80% sauerstofflimitiert. Die Geschwindigkeit laesst sich durch die Sauerstoffeintragsrate beeinflussen. Der O{sub 2}-Nutzungsgrad liegt dabei nahe am theoretischen Wert unter Beruecksichtigung weitgehender Mineralisierung und Biomassenbildung. Bei hoeheren Umsaetzen verringert sich die Abbaugeschwindigkeit deutlich aufgrund des Uebergangs von 0- zum C-limitierten Zustand. Erste Ansaetze, die Bioverfuegbarkeit zu

  2. Dose limits

    International Nuclear Information System (INIS)

    Fitoussi, L.

    1987-12-01

    The dose limit is defined to be the level of harmfulness which must not be exceeded, so that an activity can be exercised in a regular manner without running a risk unacceptable to man and the society. The paper examines the effects of radiation categorised into stochastic and non-stochastic. Dose limits for workers and the public are discussed

  3. Catastrophic Disruption Threshold and Maximum Deflection from Kinetic Impact

    Science.gov (United States)

    Cheng, A. F.

    2017-12-01

    The use of a kinetic impactor to deflect an asteroid on a collision course with Earth was described in the NASA Near-Earth Object Survey and Deflection Analysis of Alternatives (2007) as the most mature approach for asteroid deflection and mitigation. The NASA DART mission will demonstrate asteroid deflection by kinetic impact at the Potentially Hazardous Asteroid 65803 Didymos in October, 2022. The kinetic impactor approach is considered to be applicable with warning times of 10 years or more and with hazardous asteroid diameters of 400 m or less. In principle, a larger kinetic impactor bringing greater kinetic energy could cause a larger deflection, but input of excessive kinetic energy will cause catastrophic disruption of the target, leaving possibly large fragments still on collision course with Earth. Thus the catastrophic disruption threshold limits the maximum deflection from a kinetic impactor. An often-cited rule of thumb states that the maximum deflection is 0.1 times the escape velocity before the target will be disrupted. It turns out this rule of thumb does not work well. A comparison to numerical simulation results shows that a similar rule applies in the gravity limit, for large targets more than 300 m, where the maximum deflection is roughly the escape velocity at momentum enhancement factor β=2. In the gravity limit, the rule of thumb corresponds to pure momentum coupling (μ=1/3), but simulations find a slightly different scaling μ=0.43. In the smaller target size range that kinetic impactors would apply to, the catastrophic disruption limit is strength-controlled. A DART-like impactor won't disrupt any target asteroid down to significantly smaller size than the 50 m below which a hazardous object would not penetrate the atmosphere in any case unless it is unusually strong.

  4. STUDY ON MAXIMUM SPECIFIC SLUDGE ACIVITY OF DIFFERENT ANAEROBIC GRANULAR SLUDGE BY BATCH TESTS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The maximum specific sludge activity of granular sludge from large-scale UASB, IC and Biobed anaerobic reactors were investigated by batch tests. The limitation factors related to maximum specific sludge activity (diffusion, substrate sort, substrate concentration and granular size) were studied. The general principle and procedure for the precise measurement of maximum specific sludge activity were suggested. The potential capacity of loading rate of the IC and Biobed anaerobic reactors were analyzed and compared by use of the batch tests results.

  5. Nonsymmetric entropy and maximum nonsymmetric entropy principle

    International Nuclear Information System (INIS)

    Liu Chengshi

    2009-01-01

    Under the frame of a statistical model, the concept of nonsymmetric entropy which generalizes the concepts of Boltzmann's entropy and Shannon's entropy, is defined. Maximum nonsymmetric entropy principle is proved. Some important distribution laws such as power law, can be derived from this principle naturally. Especially, nonsymmetric entropy is more convenient than other entropy such as Tsallis's entropy in deriving power laws.

  6. Maximum speed of dewetting on a fiber

    NARCIS (Netherlands)

    Chan, Tak Shing; Gueudre, Thomas; Snoeijer, Jacobus Hendrikus

    2011-01-01

    A solid object can be coated by a nonwetting liquid since a receding contact line cannot exceed a critical speed. We theoretically investigate this forced wetting transition for axisymmetric menisci on fibers of varying radii. First, we use a matched asymptotic expansion and derive the maximum speed

  7. Maximum potential preventive effect of hip protectors

    NARCIS (Netherlands)

    van Schoor, N.M.; Smit, J.H.; Bouter, L.M.; Veenings, B.; Asma, G.B.; Lips, P.T.A.M.

    2007-01-01

    OBJECTIVES: To estimate the maximum potential preventive effect of hip protectors in older persons living in the community or homes for the elderly. DESIGN: Observational cohort study. SETTING: Emergency departments in the Netherlands. PARTICIPANTS: Hip fracture patients aged 70 and older who

  8. Maximum gain of Yagi-Uda arrays

    DEFF Research Database (Denmark)

    Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.

    1971-01-01

    Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

  9. Weak scale from the maximum entropy principle

    Science.gov (United States)

    Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu

    2015-03-01

    The theory of the multiverse and wormholes suggests that the parameters of the Standard Model (SM) are fixed in such a way that the radiation of the S3 universe at the final stage S_rad becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the SM, we can check whether S_rad actually becomes maximum at the observed values. In this paper, we regard S_rad at the final stage as a function of the weak scale (the Higgs expectation value) vh, and show that it becomes maximum around vh = {{O}} (300 GeV) when the dimensionless couplings in the SM, i.e., the Higgs self-coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by vh ˜ T_{BBN}2 / (M_{pl}ye5), where ye is the Yukawa coupling of electron, T_BBN is the temperature at which the Big Bang nucleosynthesis starts, and M_pl is the Planck mass.

  10. The maximum-entropy method in superspace

    Czech Academy of Sciences Publication Activity Database

    van Smaalen, S.; Palatinus, Lukáš; Schneider, M.

    2003-01-01

    Roč. 59, - (2003), s. 459-469 ISSN 0108-7673 Grant - others:DFG(DE) XX Institutional research plan: CEZ:AV0Z1010914 Keywords : maximum-entropy method, * aperiodic crystals * electron density Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.558, year: 2003

  11. Achieving maximum sustainable yield in mixed fisheries

    NARCIS (Netherlands)

    Ulrich, Clara; Vermard, Youen; Dolder, Paul J.; Brunel, Thomas; Jardim, Ernesto; Holmes, Steven J.; Kempf, Alexander; Mortensen, Lars O.; Poos, Jan Jaap; Rindorf, Anna

    2017-01-01

    Achieving single species maximum sustainable yield (MSY) in complex and dynamic fisheries targeting multiple species (mixed fisheries) is challenging because achieving the objective for one species may mean missing the objective for another. The North Sea mixed fisheries are a representative example

  12. 5 CFR 534.203 - Maximum stipends.

    Science.gov (United States)

    2010-01-01

    ... maximum stipend established under this section. (e) A trainee at a non-Federal hospital, clinic, or medical or dental laboratory who is assigned to a Federal hospital, clinic, or medical or dental... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER OTHER SYSTEMS Student...

  13. Minimal length, Friedmann equations and maximum density

    Energy Technology Data Exchange (ETDEWEB)

    Awad, Adel [Center for Theoretical Physics, British University of Egypt,Sherouk City 11837, P.O. Box 43 (Egypt); Department of Physics, Faculty of Science, Ain Shams University,Cairo, 11566 (Egypt); Ali, Ahmed Farag [Centre for Fundamental Physics, Zewail City of Science and Technology,Sheikh Zayed, 12588, Giza (Egypt); Department of Physics, Faculty of Science, Benha University,Benha, 13518 (Egypt)

    2014-06-16

    Inspired by Jacobson’s thermodynamic approach, Cai et al. have shown the emergence of Friedmann equations from the first law of thermodynamics. We extend Akbar-Cai derivation http://dx.doi.org/10.1103/PhysRevD.75.084003 of Friedmann equations to accommodate a general entropy-area law. Studying the resulted Friedmann equations using a specific entropy-area law, which is motivated by the generalized uncertainty principle (GUP), reveals the existence of a maximum energy density closed to Planck density. Allowing for a general continuous pressure p(ρ,a) leads to bounded curvature invariants and a general nonsingular evolution. In this case, the maximum energy density is reached in a finite time and there is no cosmological evolution beyond this point which leaves the big bang singularity inaccessible from a spacetime prospective. The existence of maximum energy density and a general nonsingular evolution is independent of the equation of state and the spacial curvature k. As an example we study the evolution of the equation of state p=ωρ through its phase-space diagram to show the existence of a maximum energy which is reachable in a finite time.

  14. Radiological control in a mine with a naturally-occurring radioactive material -NORM: III assessment of removable surface contamination in a pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, W.S.; Py Junior, D.A.; Silva, A.C.A.; Garcia Filho, O., E-mail: pereiraws@gmail.com [Industrias Nucleares do Brasil (INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerio. Grupo Multidisciplinar de Radioprotecao; Kelecom, A., E-mail: akelecom@id.uff.br [Universidade Federal Fluminense (GETA/LARARA-PLS/UFF), Niteroi, RJ, (Brazil). Grupo de Estudos em Temas Ambientais. Lab. de Radiobiologia e Radiometria; Pereira, J.R.S., E-mail: pereirarsj@gmail.com [Universidade Federal de Alfenas (UNIFAL), Pocos de Caldas, MG (Brazil)

    2013-07-01

    Ore Treatment Unit (OUT) possesses a process laboratory. Considering the uranium ore processing, this laboratory works in close cooperation with the Radiation Protection Service of the Unit. In the year of 2009 a pilot plant for the development of solvent uranium extraction from the phosphate ore of the mine of Santa Quiteria city, in Ceara State, Brazil was developed. In this kind of plant the surface contamination may cause contamination for Occupational Exposed Individuals (OEI). In order to control this kind of contamination and offer a safety work's condition for OEIs, a monitoring program of transferable contamination using swab samples was developed. 162 swabs were made. For the alpha emitters the monitoring results varied from 0.001 Bq cm{sup -2} to 0.014 Bq cm{sup -2}, with average value of 0.002 Bq cm{sup -2}. For beta emitters the results varied from 0.010 Bq cm{sup -2} to 0.031 Bq cm{sup -2} with average equal to 0.011 Bq cm{sup -2}. For alpha emitters, 87.65 % of the results were below 0.004 Bq cm{sup -2}, values that are one order of magnitude smaller than the limit and the maximum value stayed in 35 % of the limit for an object to be considered contaminated. For beta emitters, 90 % of the results were below 0.010 Bq cm{sup -2} that corresponds to 25 % of the limit and 100 % were below 0.031 Bq cm{sup -2} below the limit for an object to be considered contaminated. In both cases any object monitored during the operation, was not considered contaminated, proving the good practices employed in the laboratory, resultant of the good planning of the Radiation Protection Service for the operations' process. (author)

  15. Radiological control in a mine with a naturally-occurring radioactive material -NORM: III assessment of removable surface contamination in a pilot plant

    International Nuclear Information System (INIS)

    Pereira, W.S.; Py Junior, D.A.; Silva, A.C.A.; Garcia Filho, O.

    2013-01-01

    Ore Treatment Unit (OUT) possesses a process laboratory. Considering the uranium ore processing, this laboratory works in close cooperation with the Radiation Protection Service of the Unit. In the year of 2009 a pilot plant for the development of solvent uranium extraction from the phosphate ore of the mine of Santa Quiteria city, in Ceara State, Brazil was developed. In this kind of plant the surface contamination may cause contamination for Occupational Exposed Individuals (OEI). In order to control this kind of contamination and offer a safety work's condition for OEIs, a monitoring program of transferable contamination using swab samples was developed. 162 swabs were made. For the alpha emitters the monitoring results varied from 0.001 Bq cm -2 to 0.014 Bq cm -2 , with average value of 0.002 Bq cm -2 . For beta emitters the results varied from 0.010 Bq cm -2 to 0.031 Bq cm -2 with average equal to 0.011 Bq cm -2 . For alpha emitters, 87.65 % of the results were below 0.004 Bq cm -2 , values that are one order of magnitude smaller than the limit and the maximum value stayed in 35 % of the limit for an object to be considered contaminated. For beta emitters, 90 % of the results were below 0.010 Bq cm -2 that corresponds to 25 % of the limit and 100 % were below 0.031 Bq cm -2 below the limit for an object to be considered contaminated. In both cases any object monitored during the operation, was not considered contaminated, proving the good practices employed in the laboratory, resultant of the good planning of the Radiation Protection Service for the operations' process. (author)

  16. Optimal Portfolio Strategy under Rolling Economic Maximum Drawdown Constraints

    Directory of Open Access Journals (Sweden)

    Xiaojian Yu

    2014-01-01

    Full Text Available This paper deals with the problem of optimal portfolio strategy under the constraints of rolling economic maximum drawdown. A more practical strategy is developed by using rolling Sharpe ratio in computing the allocation proportion in contrast to existing models. Besides, another novel strategy named “REDP strategy” is further proposed, which replaces the rolling economic drawdown of the portfolio with the rolling economic drawdown of the risky asset. The simulation tests prove that REDP strategy can ensure the portfolio to satisfy the drawdown constraint and outperforms other strategies significantly. An empirical comparison research on the performances of different strategies is carried out by using the 23-year monthly data of SPTR, DJUBS, and 3-month T-bill. The investment cases of single risky asset and two risky assets are both studied in this paper. Empirical results indicate that the REDP strategy successfully controls the maximum drawdown within the given limit and performs best in both return and risk.

  17. Optimum detection for extracting maximum information from symmetric qubit sets

    International Nuclear Information System (INIS)

    Mizuno, Jun; Fujiwara, Mikio; Sasaki, Masahide; Akiba, Makoto; Kawanishi, Tetsuya; Barnett, Stephen M.

    2002-01-01

    We demonstrate a class of optimum detection strategies for extracting the maximum information from sets of equiprobable real symmetric qubit states of a single photon. These optimum strategies have been predicted by Sasaki et al. [Phys. Rev. A 59, 3325 (1999)]. The peculiar aspect is that the detections with at least three outputs suffice for optimum extraction of information regardless of the number of signal elements. The cases of ternary (or trine), quinary, and septenary polarization signals are studied where a standard von Neumann detection (a projection onto a binary orthogonal basis) fails to access the maximum information. Our experiments demonstrate that it is possible with present technologies to attain about 96% of the theoretical limit

  18. Maximum field capability of energy saver superconducting magnets

    International Nuclear Information System (INIS)

    Turkot, F.; Cooper, W.E.; Hanft, R.; McInturff, A.

    1983-01-01

    At an energy of 1 TeV the superconducting cable in the Energy Saver dipole magnets will be operating at ca. 96% of its nominal short sample limit; the corresponding number in the quadrupole magnets will be 81%. All magnets for the Saver are individually tested for maximum current capability under two modes of operation; some 900 dipoles and 275 quadrupoles have now been measured. The dipole winding is composed of four individually wound coils which in general come from four different reels of cable. As part of the magnet fabrication quality control a short piece of cable from both ends of each reel has its critical current measured at 5T and 4.3K. In this paper the authors describe and present the statistical results of the maximum field tests (including quench and cycle) on Saver dipole and quadrupole magnets and explore the correlation of these tests with cable critical current

  19. Optimal Control of Polymer Flooding Based on Maximum Principle

    Directory of Open Access Journals (Sweden)

    Yang Lei

    2012-01-01

    Full Text Available Polymer flooding is one of the most important technologies for enhanced oil recovery (EOR. In this paper, an optimal control model of distributed parameter systems (DPSs for polymer injection strategies is established, which involves the performance index as maximum of the profit, the governing equations as the fluid flow equations of polymer flooding, and the inequality constraint as the polymer concentration limitation. To cope with the optimal control problem (OCP of this DPS, the necessary conditions for optimality are obtained through application of the calculus of variations and Pontryagin’s weak maximum principle. A gradient method is proposed for the computation of optimal injection strategies. The numerical results of an example illustrate the effectiveness of the proposed method.

  20. A petroleum contaminated soil bioremediation facility

    Energy Technology Data Exchange (ETDEWEB)

    Lombard, K.; Hazen, T.

    1994-06-01

    The amount of petroleum contaminated soil (PCS) at the Savannah River site (SRS) that has been identified, excavated and is currently in storage has increased several fold during the last few years. Several factors have contributed to this problem: (1) South Carolina Department of Health ad Environmental control (SCDHEC) lowered the sanitary landfill maximum concentration for total petroleum hydrocarbons (TPH) in the soil from 500 to 100 parts per million (ppm), (2) removal and replacement of underground storage tanks at several sites, (3) most recently SCDHEC disallowed aeration for treatment of contaminated soil, and (4) discovery of several very large contaminated areas of soil associated with leaking underground storage tanks (LUST), leaking pipes, disposal areas, and spills. Thus, SRS has an urgent need to remediate large quantities of contaminated soil that are currently stockpiled and the anticipated contaminated soils to be generated from accidental spills. As long as we utilize petroleum based compounds at the site, we will continue to generate contaminated soil that will require remediation.

  1. A petroleum contaminated soil bioremediation facility

    International Nuclear Information System (INIS)

    Lombard, K.; Hazen, T.

    1994-01-01

    The amount of petroleum contaminated soil (PCS) at the Savannah River site (SRS) that has been identified, excavated and is currently in storage has increased several fold during the last few years. Several factors have contributed to this problem: (1) South Carolina Department of Health ad Environmental control (SCDHEC) lowered the sanitary landfill maximum concentration for total petroleum hydrocarbons (TPH) in the soil from 500 to 100 parts per million (ppm), (2) removal and replacement of underground storage tanks at several sites, (3) most recently SCDHEC disallowed aeration for treatment of contaminated soil, and (4) discovery of several very large contaminated areas of soil associated with leaking underground storage tanks (LUST), leaking pipes, disposal areas, and spills. Thus, SRS has an urgent need to remediate large quantities of contaminated soil that are currently stockpiled and the anticipated contaminated soils to be generated from accidental spills. As long as we utilize petroleum based compounds at the site, we will continue to generate contaminated soil that will require remediation

  2. Derived limits and their practical applications

    International Nuclear Information System (INIS)

    Minarik, F.

    1982-01-01

    Attention is devoted to the approach and methodological procedure in determining derived limits for surface contamination with special regard to external exposure of hands, inhalation of resuspended activity, contamination of the skin and with regard to ingestion of radioactive material from the skin. In the practical part of the article, results are given of measuring contamination by radionuclides 134 Cs, 133 Cs and 60 Co, and the resulting annual equivalent dose rates and their comparison with derived air contamination in the sense of ICRP Publ. No. 30. (author)

  3. Contamination levels of aflatoxin M1 in bulk raw milk of Chaloos and Ramsar

    Directory of Open Access Journals (Sweden)

    A.R Barami

    2012-02-01

    Full Text Available Aflatoxin M1 (AFM1 appears in milk as a direct result of the ingestion of feed contaminated with aflatoxin B1 by cattle. This study was conducted to investigate the contamination rate of raw milk whit aflatoxin M1 in Chaloos and Ramsar raw milk collection centers. Two hundred bulk raw milk samples were collected during winter (January and February and summer (June and July seasons. The milk samples were analyzed by ELISA method for the presence of AFM1. During the winter, AFM1 was detected in 100% and 59/79% of the bulk raw milk samples in Ramsar and Chaloos, respectively; however, during summer 83/52% and 50/1 of the samples was found as positive in Ramsar and Chaloos, respectively. Furthermore, 45% of Ramsar and 30% of Chaloos bulk milk samples showed higher contamination level of AFM1 than maximum tolerance limit (50 ng/l accepted by National Standard as well as European Union. Although, the difference between the contamination rate in samples obtained during summer and winter seasons was not statistically significantly, (p

  4. Monitoring pesticides residues and contaminants for some leafy vegetables at the market level

    International Nuclear Information System (INIS)

    Ibrahim, A. B. H.

    2004-03-01

    Pesticide residues and contaminants in selected leafy vegetables, namely (lettuce, garden rocket and salad onion) were monitored at market level in Riyadh City in Saudi Arabia, during the period june to july 2001. Fifteen samples of vegetables from the City vegetable market of Riyadh were collected and subjected to multi-pesticide residue detection and analysis by gas chromatography with mass spectrometer and electron capture detectors (GC/MS,ECD). Results of sample extracts analysis showed that the two vegetables of: garden rocket and salad onion contain pesticide residues and contaminants which have no Maximum Residue Limits (MRL) prescribed by Codex Alimentarius Commission (CAC) collaborate with World Health and Food and Agriculture Organizations (WHO/FAO). Whereas lettuce vegetable was found free of any identified pesticide residues or contaminants. Garden rocket was shown to contain dibutyl phthalate (0.04 ppm)-steryl chloride (0.02 ppm) tridecane (0.06 ppm)-hexadecane (0.07 ppm)-BIS (ethylhexyl) phthalate (0.006 ppm) and pyridinium, 1-hexyl chloride (0.01 ppm). The salad onion was found to contain 9-octadecanamide (0.13 ppm)-tridecane (0.15 ppm) and tetradecane (0.16 ppm). There are no established MRL s for these pesticides and contaminants detected in garden rocket and salad onion, although when impacts on human health were reviewed some of them were found probably hazardous. (Author)

  5. Baseline risk assessment for groundwater contamination at the uranium mill tailings site, Gunnison, Colorado

    International Nuclear Information System (INIS)

    1990-11-01

    The Gunnison Baseline Risk Assessment for Groundwater Contamination at the Uranium Mill Tailings Site was performed to determine if long-term use of groundwater from domestic wells near the site has a potential for adverse health effects. The risk assessment was based on the results of sampling domestic wells during 1989--1990. A risk assessment evaluates health risks by comparing the amount of a contaminant taken in by a person with the amount of the contaminant that may be toxic. The Gunnison Risk Assessment used high intake values to estimate the maximum levels a person might be exposed to. The results of the risk assessment are divided into cancer (carcinogenic) risks and non-carcinogenic risks. Five key contaminants were evaluated for adverse health risks: uranium, manganese, lead antimony, and cadmium. Due to the potential health risks and the unavoidable uncertainties associated with limited groundwater and toxicity data, it is prudent public health policy to provide a permanent alternate water supply. Additionally, providing a permanent alternate water supply is cost-effective compared to long-term routine monitoring

  6. Inverse Limits

    CERN Document Server

    Ingram, WT

    2012-01-01

    Inverse limits provide a powerful tool for constructing complicated spaces from simple ones. They also turn the study of a dynamical system consisting of a space and a self-map into a study of a (likely more complicated) space and a self-homeomorphism. In four chapters along with an appendix containing background material the authors develop the theory of inverse limits. The book begins with an introduction through inverse limits on [0,1] before moving to a general treatment of the subject. Special topics in continuum theory complete the book. Although it is not a book on dynamics, the influen

  7. Modelling information flow along the human connectome using maximum flow.

    Science.gov (United States)

    Lyoo, Youngwook; Kim, Jieun E; Yoon, Sujung

    2018-01-01

    The human connectome is a complex network that transmits information between interlinked brain regions. Using graph theory, previously well-known network measures of integration between brain regions have been constructed under the key assumption that information flows strictly along the shortest paths possible between two nodes. However, it is now apparent that information does flow through non-shortest paths in many real-world networks such as cellular networks, social networks, and the internet. In the current hypothesis, we present a novel framework using the maximum flow to quantify information flow along all possible paths within the brain, so as to implement an analogy to network traffic. We hypothesize that the connection strengths of brain networks represent a limit on the amount of information that can flow through the connections per unit of time. This allows us to compute the maximum amount of information flow between two brain regions along all possible paths. Using this novel framework of maximum flow, previous network topological measures are expanded to account for information flow through non-shortest paths. The most important advantage of the current approach using maximum flow is that it can integrate the weighted connectivity data in a way that better reflects the real information flow of the brain network. The current framework and its concept regarding maximum flow provides insight on how network structure shapes information flow in contrast to graph theory, and suggests future applications such as investigating structural and functional connectomes at a neuronal level. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Heavy metal contamination in vegetables grown in Rawalpindi, Pakistan

    International Nuclear Information System (INIS)

    Ahmed, W.; Ahmed, A.; Ahmad, A.; Randhawa, M.A.; Ahmad, R.; Khalid, N.

    2012-01-01

    Copper (Cu), cadmium (Cd), chromium (Cr) nickel (Ni), lead (Pb), Iron (Fe), Manganese (Mn) and zinc (Zn) contents of various vegetables (bitter melon, tomato, eggplant, lettuce, cucumber and bell pepper) produced in Rawalpindi, Pakistan was determined using Atomic absorption spectrophotometer (AAS). These plants are the basis of human nutrition in the study area. All vegetables grown at sewage water by farmers showed the highest contamination of heavy metals, followed by local market, Progressive farmers and hydroponic plant. The concentration ranges in mg/kg were (1.45 -2.55) for Cd, (3.10 to 4.92) Cr, (12.15- 20.50) Cu, (25.00-51.00) for Fe, (7.80 to 15.60) for Mn, (10.16 to 15.42) for Ni, (2.12 to 5.41) Pb and (16.58 to 24.08) for zinc. The contamination was above the Maximum Residue Limits (MRLs), set out by WHO. Irregular trends in concentration were also observed in vegetables obtained from local market, progressive farmers and hydroponic plant. (author)

  9. The role of pressure anisotropy on the maximum mass of cold ...

    Indian Academy of Sciences (India)

    ,. Pune 411 007, India. 3 ... red-shift and mass increase in the presence of anisotropic pressures; numerical values are generated which are in ... that anisotropy may also change the limiting values of the maximum mass of com- pact stars.

  10. 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

  11. JPL Contamination Control Engineering

    Science.gov (United States)

    Blakkolb, Brian

    2013-01-01

    JPL has extensive expertise fielding contamination sensitive missions-in house and with our NASA/industry/academic partners.t Development and implementation of performance-driven cleanliness requirements for a wide range missions and payloads - UV-Vis-IR: GALEX, Dawn, Juno, WFPC-II, AIRS, TES, et al - Propulsion, thermal control, robotic sample acquisition systems. Contamination control engineering across the mission life cycle: - System and payload requirements derivation, analysis, and contamination control implementation plans - Hardware Design, Risk trades, Requirements V-V - Assembly, Integration & Test planning and implementation - Launch site operations and launch vehicle/payload integration - Flight ops center dot Personnel on staff have expertise with space materials development and flight experiments. JPL has capabilities and expertise to successfully address contamination issues presented by space and habitable environments. JPL has extensive experience fielding and managing contamination sensitive missions. Excellent working relationship with the aerospace contamination control engineering community/.

  12. Limiting values for radioactive materials in food

    International Nuclear Information System (INIS)

    Steiner, Martin

    2014-01-01

    The contribution describes the fundamentals of radiation protection: LNT (linear, no threshold) hypotheses, ALARA (a slow as reasonably achievable), limiting values. Using the example the nuclear accident in Chernobyl the differences in contamination development in different foodstuffs in Germany is demonstrated including recommended limiting values and the radiation exposures after 30 years due to consumption of contaminated food. The natural radioactivity is about 0.3 mSv/year.

  13. [Evolutionary process unveiled by the maximum genetic diversity hypothesis].

    Science.gov (United States)

    Huang, Yi-Min; Xia, Meng-Ying; Huang, Shi

    2013-05-01

    As two major popular theories to explain evolutionary facts, the neutral theory and Neo-Darwinism, despite their proven virtues in certain areas, still fail to offer comprehensive explanations to such fundamental evolutionary phenomena as the genetic equidistance result, abundant overlap sites, increase in complexity over time, incomplete understanding of genetic diversity, and inconsistencies with fossil and archaeological records. Maximum genetic diversity hypothesis (MGD), however, constructs a more complete evolutionary genetics theory that incorporates all of the proven virtues of existing theories and adds to them the novel concept of a maximum or optimum limit on genetic distance or diversity. It has yet to meet a contradiction and explained for the first time the half-century old Genetic Equidistance phenomenon as well as most other major evolutionary facts. It provides practical and quantitative ways of studying complexity. Molecular interpretation using MGD-based methods reveal novel insights on the origins of humans and other primates that are consistent with fossil evidence and common sense, and reestablished the important role of China in the evolution of humans. MGD theory has also uncovered an important genetic mechanism in the construction of complex traits and the pathogenesis of complex diseases. We here made a series of sequence comparisons among yeasts, fishes and primates to illustrate the concept of limit on genetic distance. The idea of limit or optimum is in line with the yin-yang paradigm in the traditional Chinese view of the universal creative law in nature.

  14. Maximum concentrations at work and maximum biologically tolerable concentration for working materials 1991

    International Nuclear Information System (INIS)

    1991-01-01

    The meaning of the term 'maximum concentration at work' in regard of various pollutants is discussed. Specifically, a number of dusts and smokes are dealt with. The valuation criteria for maximum biologically tolerable concentrations for working materials are indicated. The working materials in question are corcinogeneous substances or substances liable to cause allergies or mutate the genome. (VT) [de

  15. 75 FR 43840 - Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum Civil Monetary Penalties for...

    Science.gov (United States)

    2010-07-27

    ...-17530; Notice No. 2] RIN 2130-ZA03 Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum... remains at $250. These adjustments are required by the Federal Civil Penalties Inflation Adjustment Act [email protected] . SUPPLEMENTARY INFORMATION: The Federal Civil Penalties Inflation Adjustment Act of 1990...

  16. Organization of internal contamination monitoring

    International Nuclear Information System (INIS)

    Badreddine, A.

    1986-07-01

    The nuclear energy takes a big part in the world's energy production. The nuclear techniques are used in most fields of life. Nevertheless the use of radioactive materials may cause prejudice to human beings by radiation contamination. The International Commission on Radiological Protection gives the general rules and regulations to avoid this danger. In the publication No. 30, the ICRP gives a metabolic model for the respiratory system and values of Annual Limit of Intake. The ALI for inhalation supposes a standard AMAD (Activity Median Aerodynamic Diameter) of 1 um. We have measured the AMAD in a laboratory under different conditions of functioning in order to show its variation. Then we have analysed the effect of this variation on the internal contamination monitoring. Thus we have calculated the Effective Committed Dose (ECD), the ALI, then the Derived Investigation Level (DIL) for different values of AMAD for Whole-Body Counting (WBC)

  17. RADIATION CONTAMINATION INCIDENT AT ISOLDE

    CERN Multimedia

    2000-01-01

    On 27 June 2000 three specialists were investigating a problem with the extraction electrode of the high-resolution separator (HRS) in Isolde. Whilst using an endoscope in order to have a closer look at the interior, they came into contact with radioactive dust and became contaminated. The level of contamination was low and the radiation dose received by the 3 persons was far below the effective dose limit given in the CERN Radiation Safety Manual and in the regulations of the Host States.According to the usual procedure, the Director General has set up a Fact-Finding Group and an Accident Board in order to advise him on the steps and decisions tobe taken following this incident and in particular to avoid a recurrence.

  18. Zipf's law, power laws and maximum entropy

    International Nuclear Information System (INIS)

    Visser, Matt

    2013-01-01

    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines—from astronomy to demographics to software structure to economics to linguistics to zoology, and even warfare. A recent model of random group formation (RGF) attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present paper I argue that the specific cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified. (paper)

  19. Maximum-entropy description of animal movement.

    Science.gov (United States)

    Fleming, Chris H; Subaşı, Yiğit; Calabrese, Justin M

    2015-03-01

    We introduce a class of maximum-entropy states that naturally includes within it all of the major continuous-time stochastic processes that have been applied to animal movement, including Brownian motion, Ornstein-Uhlenbeck motion, integrated Ornstein-Uhlenbeck motion, a recently discovered hybrid of the previous models, and a new model that describes central-place foraging. We are also able to predict a further hierarchy of new models that will emerge as data quality improves to better resolve the underlying continuity of animal movement. Finally, we also show that Langevin equations must obey a fluctuation-dissipation theorem to generate processes that fall from this class of maximum-entropy distributions when the constraints are purely kinematic.

  20. Pareto versus lognormal: a maximum entropy test.

    Science.gov (United States)

    Bee, Marco; Riccaboni, Massimo; Schiavo, Stefano

    2011-08-01

    It is commonly found that distributions that seem to be lognormal over a broad range change to a power-law (Pareto) distribution for the last few percentiles. The distributions of many physical, natural, and social events (earthquake size, species abundance, income and wealth, as well as file, city, and firm sizes) display this structure. We present a test for the occurrence of power-law tails in statistical distributions based on maximum entropy. This methodology allows one to identify the true data-generating processes even in the case when it is neither lognormal nor Pareto. The maximum entropy approach is then compared with other widely used methods and applied to different levels of aggregation of complex systems. Our results provide support for the theory that distributions with lognormal body and Pareto tail can be generated as mixtures of lognormally distributed units.

  1. A Maximum Radius for Habitable Planets.

    Science.gov (United States)

    Alibert, Yann

    2015-09-01

    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.

  2. Maximum parsimony on subsets of taxa.

    Science.gov (United States)

    Fischer, Mareike; Thatte, Bhalchandra D

    2009-09-21

    In this paper we investigate mathematical questions concerning the reliability (reconstruction accuracy) of Fitch's maximum parsimony algorithm for reconstructing the ancestral state given a phylogenetic tree and a character. In particular, we consider the question whether the maximum parsimony method applied to a subset of taxa can reconstruct the ancestral state of the root more accurately than when applied to all taxa, and we give an example showing that this indeed is possible. A surprising feature of our example is that ignoring a taxon closer to the root improves the reliability of the method. On the other hand, in the case of the two-state symmetric substitution model, we answer affirmatively a conjecture of Li, Steel and Zhang which states that under a molecular clock the probability that the state at a single taxon is a correct guess of the ancestral state is a lower bound on the reconstruction accuracy of Fitch's method applied to all taxa.

  3. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    An environmental investigation of ground water conditions has been undertaken at Wright-Patterson Air Force Base (WPAFB), Ohio to obtain data to assist in the evaluation of a potential removal action to prevent, to the extent practicable, migration of the contaminated ground water across Base boundaries. Field investigations were limited to the central section of the southwestern boundary of Area C and the Springfield Pike boundary of Area B. Further, the study was limited to a maximum depth of 150 feet below grade. Three primary activities of the field investigation were: (1) installation of 22 monitoring wells, (2) collection and analysis of ground water from 71 locations, (3) measurement of ground water elevations at 69 locations. Volatile organic compounds including trichloroethylene, perchloroethylene, and/or vinyl chloride were detected in concentrations exceeding Maximum Contaminant Levels (MCL) at three locations within the Area C investigation area. Ground water at the Springfield Pike boundary of Area B occurs in two primary units, separated by a thicker-than-expected clay layers. One well within Area B was determined to exceed the MCL for trichloroethylene.

  4. Limited field investigation report for the 100-HR-3 operable unit

    International Nuclear Information System (INIS)

    1994-09-01

    This limited field investigation (LFI) was conducted to assess the applicability of interim remedial measures (IRM) for reducing human health and environmental risks within the 100-HR-3 Groundwater Operable Unit. The 100-HR-3 Operable Unit is comprised of three subareas; the 100 D Area, the 100 H Area and those portions of the 600 Area between the two reactor areas. The operable unit is one of seven operable units associated with the 100 D and H Areas. Operable units 100-DR-1, 100-DR-2, 100-DR-3, 100-HR-1, 100-HR-2 and 100-IU-4 address contaminant sources while 100-HR-3 addresses contamination present in the underlying groundwater. The primary method of field investigation used during this LFI was the installation and sampling of monitoring wells. Samples were collected from the groundwater and soils, and submitted for laboratory analysis. Boreholes were surveyed for radiological contamination using downhole geophysical techniques to further delineate the locations and levels of contaminants. All samples were screened to ascertain the presence of volatile organic compounds and radionuclides. Analytical data were subjected to validation; all round one, two and three and a minimum of 10% of round four data associated with the LFI were validated. A screening method was used to identify contaminants of potential concern (COPC). This screening method eliminated from further consideration, constituents that were below background. Constituents which are considered non-toxic to humans were eliminated from the human health evaluation. Data consistency and blank contamination were also evaluated in the screening process. These COPC were then evaluated further in the qualitative risk assessment (QRA). A human health QRA was performed using conservative (maximum equilibrated contaminant levels from the LFI) analyses

  5. Contamination with iodine-131 in metabolic therapy

    International Nuclear Information System (INIS)

    Garcia, R.; Luis, J.; Gomez, A.; Gonzalez, V.; Herrador, M.; Rogriguez, J.R.

    1997-01-01

    High-dose radioactive iodine therapy using 131 I is the treatment of choice for patients with thyroid cancer following thyroidectomy. Because of the large amount of activity which is excreted during hospitalization, contamination harzard from 131 I excretion via perspiration, saliva, breath and urine may arise. In twelve patients treated with doses of 131 I ranging from 1.85-7.4GBq activity levels were measured in room surface, the toilet, patients saliva and skin. Removable activity from skin reached a maximum at 24h post-therapy. Removable activity from room surfaces exceed the level of contamination which requires clean-up in a public area during patient's hospitalization. The relatively high activities present in the saliva and skin of these patients emphasizes the need for all individuals coming in contact with these patients to be made aware of the contamination hazard present. (author)

  6. A Maximum Resonant Set of Polyomino Graphs

    Directory of Open Access Journals (Sweden)

    Zhang Heping

    2016-05-01

    Full Text Available A polyomino graph P is a connected finite subgraph of the infinite plane grid such that each finite face is surrounded by a regular square of side length one and each edge belongs to at least one square. A dimer covering of P corresponds to a perfect matching. Different dimer coverings can interact via an alternating cycle (or square with respect to them. A set of disjoint squares of P is a resonant set if P has a perfect matching M so that each one of those squares is M-alternating. In this paper, we show that if K is a maximum resonant set of P, then P − K has a unique perfect matching. We further prove that the maximum forcing number of a polyomino graph is equal to the cardinality of a maximum resonant set. This confirms a conjecture of Xu et al. [26]. We also show that if K is a maximal alternating set of P, then P − K has a unique perfect matching.

  7. maximum neutron flux at thermal nuclear reactors

    International Nuclear Information System (INIS)

    Strugar, P.

    1968-10-01

    Since actual research reactors are technically complicated and expensive facilities it is important to achieve savings by appropriate reactor lattice configurations. There is a number of papers, and practical examples of reactors with central reflector, dealing with spatial distribution of fuel elements which would result in higher neutron flux. Common disadvantage of all the solutions is that the choice of best solution is done starting from the anticipated spatial distributions of fuel elements. The weakness of these approaches is lack of defined optimization criteria. Direct approach is defined as follows: determine the spatial distribution of fuel concentration starting from the condition of maximum neutron flux by fulfilling the thermal constraints. Thus the problem of determining the maximum neutron flux is solving a variational problem which is beyond the possibilities of classical variational calculation. This variational problem has been successfully solved by applying the maximum principle of Pontrjagin. Optimum distribution of fuel concentration was obtained in explicit analytical form. Thus, spatial distribution of the neutron flux and critical dimensions of quite complex reactor system are calculated in a relatively simple way. In addition to the fact that the results are innovative this approach is interesting because of the optimization procedure itself [sr

  8. Analysis of food contaminants

    National Research Council Canada - National Science Library

    Gilbert, John

    1984-01-01

    ... quantification methods used in the analysis of mycotoxins in foods - Confirmation and quantification of trace organic food contaminants by mass spectrometry-selected ion monitoring - Chemiluminescence...

  9. Solar maximum mission panel jettison analysis remote manipulator system

    Science.gov (United States)

    Bauer, R. B.

    1980-01-01

    A study is presented of the development of the Remote Manipulator System (RMS) configurations for jettison of the solar panels on the Solar Maximum Mission/Multimission Satellite. A valid RMS maneuver between jettison configurations was developed. Arm and longeron loads and effector excursions due to the solar panel jettison were determined to see if they were within acceptable limits. These loads and end effector excursions were analyzed under two RMS modes, servos active in position hold submode, and in the brakes on mode.

  10. Maximum discharge rate of liquid-vapor mixtures from vessels

    International Nuclear Information System (INIS)

    Moody, F.J.

    1975-09-01

    A discrepancy exists in theoretical predictions of the two-phase equilibrium discharge rate from pipes attached to vessels. Theory which predicts critical flow data in terms of pipe exit pressure and quality severely overpredicts flow rates in terms of vessel fluid properties. This study shows that the discrepancy is explained by the flow pattern. Due to decompression and flashing as fluid accelerates into the pipe entrance, the maximum discharge rate from a vessel is limited by choking of a homogeneous bubbly mixture. The mixture tends toward a slip flow pattern as it travels through the pipe, finally reaching a different choked condition at the pipe exit

  11. Evolution of the contamination rate in game

    International Nuclear Information System (INIS)

    Eriksson, O.; Jungskaer, W.; Gaichenko, V.; Panov, G.; Goshchak, S.; Chizevsky, I.; Kurman, A.; Jones, B.; Ryabtsev, I.; Sokolov, V.; Shcherbatchenko, A.; Davydchuk, V.; Petrov, M.; Averin, V.; Mikhalusyov, V.

    1996-01-01

    The Chernobyl accident caused considerable contamination of natural environments in large parts of Europe. In the most heavily contaminated areas close to the reactor site tissues from two wild animal species (wild boar, Sus scrofa and roe deer, Capreolus capreolus [L]) have been sampled for determination of radioactive contamination. The level of 137 Cs has been determined in a large number of samples and other radionuclides like 90 Sr in some samples. Systematic samplings during different seasons of the year have been made of these two species within the framework of the ECP9 project. The results show that there is a considerable individual variation within each season for both these species and also a seasonal variation most pronounced in wild boar. For the wild boar the minimum levels of 137 Cs are seen during summer (end of August) and autumn (end of October) and maximum levels in winter (end of February). In the roe deer the maximum levels are seen in spring (end of May) and minimum in summer. These variations reflects the feed selection during different seasons of the year. The level of 137 Cs contamination in muscular tissue has not decreased noticeably during the study period from summer 1992 to winter 1995

  12. Force Limit System

    Science.gov (United States)

    Pawlik, Ralph; Krause, David; Bremenour, Frank

    2011-01-01

    The Force Limit System (FLS) was developed to protect test specimens from inadvertent overload. The load limit value is fully adjustable by the operator and works independently of the test system control as a mechanical (non-electrical) device. When a test specimen is loaded via an electromechanical or hydraulic test system, a chance of an overload condition exists. An overload applied to a specimen could result in irreparable damage to the specimen and/or fixturing. The FLS restricts the maximum load that an actuator can apply to a test specimen. When testing limited-run test articles or using very expensive fixtures, the use of such a device is highly recommended. Test setups typically use electronic peak protection, which can be the source of overload due to malfunctioning components or the inability to react quickly enough to load spikes. The FLS works independently of the electronic overload protection.

  13. Application of Maximum Entropy Distribution to the Statistical Properties of Wave Groups

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The new distributions of the statistics of wave groups based on the maximum entropy principle are presented. The maximum entropy distributions appear to be superior to conventional distributions when applied to a limited amount of information. Its applications to the wave group properties show the effectiveness of the maximum entropy distribution. FFT filtering method is employed to obtain the wave envelope fast and efficiently. Comparisons of both the maximum entropy distribution and the distribution of Longuet-Higgins (1984) with the laboratory wind-wave data show that the former gives a better fit.

  14. Evaluation of maximum radionuclide concentration from decay chains migration in aquifers

    International Nuclear Information System (INIS)

    Aquino Branco, O.E. de.

    1983-01-01

    The mathematical formulation of the mechanisms involved in the transport of contaminants in aquifers is presented. The methodology employed is described. A method of calculation the maximum concentration of radionuclides migrating in the underground water, and resulting from one decay chain, is then proposed. As an example, the methodology is applied to a waste basin, built to receive effluents from a hypothectical uranium ore mining and milling facility. (M.A.C.) [pt

  15. Health risk evaluation of certain compounds found in contaminated soil

    International Nuclear Information System (INIS)

    Dock, L.; Victorin, K.; Vahter, M.; Ahlborg, U.G.

    1991-01-01

    As part of a redevelopment plan for an old gas works site in Stockholm, the Institute of Environmental Medicine (IEM) at the Karolinska Institute was asked to evaluate the health risks associated with exposure to coal tar, containing polycyclic aromatic hydrocarbons (PAH), phenols, cyanides, sulfur compounds, arsenic, lead, cadmium and mercury in soil and to suggest guide line values for these compounds in residential areas. Our health risk evaluation was limited to possible effects following direct exposure to contaminated soil. Indirect exposure, i.e. through contaminated ground water or home-grown vegetables, was not considered, nor were effects on building material. The routes of exposure considered were ingestion, dermal contact and inhalation of soil dust. Small children were considered the primary risk group. The critical health effect associated with dermal exposure to PAH in soil is skin cancer. Ingestion of phenols, cyanides and sulphur compounds may cause acute health effects. Recommended guide line values for these contaminants were generally obtained by dividing the lowest observed effect levels with appropriate safety factors. The metals considered may cause both acute and chronic health effects. The guide line values for cadmium and mercury in soil were set based on a maximum intake through ingestion of soil corresponding to 10% of the provisional tolerable weekly intake levels (PTWI) set by FAO/WHO. For arsenic, the guide line value corresponds to 5% of the PTWI-value for a child. The suggested guide line level for lead was based on studied on the association between soil lead concentration and blood lead levels in children. The suggested guide line level for lead in soil may increase the blood-lead in a child by less than 10%. (31 refs.) (au)

  16. 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.)

  17. Environmental contaminants of emerging concern in seafood--European database on contaminant levels.

    Science.gov (United States)

    Vandermeersch, Griet; Lourenço, Helena Maria; Alvarez-Muñoz, Diana; Cunha, Sara; Diogène, Jorge; Cano-Sancho, German; Sloth, Jens J; Kwadijk, Christiaan; Barcelo, Damia; Allegaert, Wim; Bekaert, Karen; Fernandes, José Oliveira; Marques, Antonio; Robbens, Johan

    2015-11-01

    Marine pollution gives rise to concern not only about the environment itself but also about the impact on food safety and consequently on public health. European authorities and consumers have therefore become increasingly worried about the transfer of contaminants from the marine environment to seafood. So-called "contaminants of emerging concern" are chemical substances for which no maximum levels have been laid down in EU legislation, or substances for which maximum levels have been provided but which require revision. Adequate information on their presence in seafood is often lacking and thus potential risks cannot be excluded. Assessment of food safety issues related to these contaminants has thus become urgent and imperative. A database (www.ecsafeseafooddbase.eu), containing available information on the levels of contaminants of emerging concern in seafood and providing the most recent data to scientists and regulatory authorities, was developed. The present paper reviews a selection of contaminants of emerging concern in seafood including toxic elements, endocrine disruptors, brominated flame retardants, pharmaceuticals and personal care products, polycyclic aromatic hydrocarbons and derivatives, microplastics and marine toxins. Current status on the knowledge of human exposure, toxicity and legislation are briefly presented and the outcome from scientific publications reporting on the levels of these compounds in seafood is presented and discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Contaminated soil concrete blocks

    NARCIS (Netherlands)

    de Korte, A.C.J.; Brouwers, Jos; Limbachiya, Mukesh C.; Kew, Hsein Y.

    2009-01-01

    According to Dutch law the contaminated soil needs to be remediated or immobilised. The main focus in this article is the design of concrete blocks, containing contaminated soil, that are suitable for large production, financial feasible and meets all technical and environmental requirements. In

  19. Contamination Control Techniques

    Energy Technology Data Exchange (ETDEWEB)

    EBY, J.L.

    2000-05-16

    Welcome to a workshop on contamination Control techniques. This work shop is designed for about two hours. Attendee participation is encouraged during the workshop. We will address different topics within contamination control techniques; present processes, products and equipment used here at Hanford and then open the floor to you, the attendees for your input on the topics.

  20. Contamination Control Techniques

    International Nuclear Information System (INIS)

    EBY, J.L.

    2000-01-01

    Welcome to a workshop on contamination Control techniques. This work shop is designed for about two hours. Attendee participation is encouraged during the workshop. We will address different topics within contamination control techniques; present processes, products and equipment used here at Hanford and then open the floor to you, the attendees for your input on the topics

  1. Guide to treatment technology for contaminated soils

    International Nuclear Information System (INIS)

    Tran, H.; Aylward, R.

    1992-01-01

    This document is a guide for the screening of alternative treatment technologies for contaminated soils. The contents of this guide are organized into: 1. Introduction, II. Utilizing the table, III. Tables: Contamination Versus Technology, TV. Contaminant Waste Groups, and V. References. The four Contaminations Versus Technology tables are designed to identify the effectiveness and/or potential applicability of technologies to some or all compounds within specific waste groups. The tables also present limitations and special use considerations for the particular treatment technology. The phase of development of the technology is also included in the table. The phases are: Available, Innovative, and Emerging technologies. The technologies presented in this guide are organized according to the method of treatment. The four (4) treatment methods are Biological, Solidification/Stabilization, Thermal, and Chemical/Physical Treatment. There are several processing methods; some are well developed and proven, and others are in the development stage

  2. Contaminated metallic melt volume reduction testing

    International Nuclear Information System (INIS)

    Deichman, J.L.

    1981-01-01

    Laboratory scale metallic melts (stainless steel) were accomplished in support of Decontamination and Decommissioning's (D and D) contaminated equipment volume reduction and Low-Level Lead Site Waste programs. Six laboratory scale melts made with contaminated stainless steel provided data that radionuclide distribution can be predicted when proper temperature rates and ranges are employed, and that major decontamination occurs with the use of designed slagging materials. Stainless steel bars were contaminated with plutonium, cobalt, cesium and europium. This study was limited to stainless steel, however, further study is desirable to establish data for other metals and alloys. This study represents a positive beginning in defining the feasibility of economical volume reduction or conversion from TRU waste forms to LLW forms for a large portion of approximately 50 thousand tons of contaminated metal waste now being stored at Hanford underground or in deactivated facilities

  3. Examination of health status of population from Uranium contaminated regions

    International Nuclear Information System (INIS)

    Milacic, S.; Jovicic, D.; Pantelic, G.; Kovacevic, R.; Pavlovic, M.; Tanaskovic, I.

    2002-01-01

    Uranium is widely distributed in the natural environment: in the soil, air and food. And thus all people on the planet inhale or ingest small quantities of uranium every day. However, depleted uranium (DU) is industrial product. It is used in medicine, aviation, astronomy, oil exploitation, as well as for military purposes for penetrating ammunition. America is not the only country that applies depleted uranium ammunition. It is a part of the military arsenal in France, England, Turkey, Israel, Russia, Saudi Arabia, Pakistan and Thailand. Depleted uranium is toxic for both humans and animals for two basic reasons: as a heavy metal, it has toxic chemical effects, and as an alpha-emitter, it also has radioactive effects. Although it is considered less radioactive than natural uranium, its toxicity is high due to high LET (linear energetic transfer) irradiation, tissue deposition (bones, kidneys, blood, lungs) and elimination time (5000 days). Radiation limit above which adverse health effects are initiated (radiation carcinogenic risk), depends on the quantity and contamination time (how much and how long), including also other factors, such as age, sex, previous health status, exposure to other materials, genetic predisposition and radiosensitivity (lack of indicators), diet and stress. According to ICRP recommendations, carcinogenic risk for the occupationally exposed individuals is minimal if the exposure is limited to the effective dose of 100 mSv for five years and not above 50 in a single year, being five times lower for general population. In average annual effective dose per population, from all sources is below 1mSv, carcinogenic risk will range from 1 per 10 000 to 1 per 100 000, and in occupationally exposed individuals exposed to maximum permitted doses (MPD), the risk of cancer with fatal outcome is below 3 per 100 000). Immediate effects of population exposure to low uranium doses do not result in evident clinical picture. Late consequences include

  4. Maximum entropy decomposition of quadrupole mass spectra

    International Nuclear Information System (INIS)

    Toussaint, U. von; Dose, V.; Golan, A.

    2004-01-01

    We present an information-theoretic method called generalized maximum entropy (GME) for decomposing mass spectra of gas mixtures from noisy measurements. In this GME approach to the noisy, underdetermined inverse problem, the joint entropies of concentration, cracking, and noise probabilities are maximized subject to the measured data. This provides a robust estimation for the unknown cracking patterns and the concentrations of the contributing molecules. The method is applied to mass spectroscopic data of hydrocarbons, and the estimates are compared with those received from a Bayesian approach. We show that the GME method is efficient and is computationally fast

  5. Maximum power operation of interacting molecular motors

    DEFF Research Database (Denmark)

    Golubeva, Natalia; Imparato, Alberto

    2013-01-01

    , as compared to the non-interacting system, in a wide range of biologically compatible scenarios. We furthermore consider the case where the motor-motor interaction directly affects the internal chemical cycle and investigate the effect on the system dynamics and thermodynamics.......We study the mechanical and thermodynamic properties of different traffic models for kinesin which are relevant in biological and experimental contexts. We find that motor-motor interactions play a fundamental role by enhancing the thermodynamic efficiency at maximum power of the motors...

  6. Maximum entropy method in momentum density reconstruction

    International Nuclear Information System (INIS)

    Dobrzynski, L.; Holas, A.

    1997-01-01

    The Maximum Entropy Method (MEM) is applied to the reconstruction of the 3-dimensional electron momentum density distributions observed through the set of Compton profiles measured along various crystallographic directions. It is shown that the reconstruction of electron momentum density may be reliably carried out with the aid of simple iterative algorithm suggested originally by Collins. A number of distributions has been simulated in order to check the performance of MEM. It is shown that MEM can be recommended as a model-free approach. (author). 13 refs, 1 fig

  7. On the maximum drawdown during speculative bubbles

    Science.gov (United States)

    Rotundo, Giulia; Navarra, Mauro

    2007-08-01

    A taxonomy of large financial crashes proposed in the literature locates the burst of speculative bubbles due to endogenous causes in the framework of extreme stock market crashes, defined as falls of market prices that are outlier with respect to the bulk of drawdown price movement distribution. This paper goes on deeper in the analysis providing a further characterization of the rising part of such selected bubbles through the examination of drawdown and maximum drawdown movement of indices prices. The analysis of drawdown duration is also performed and it is the core of the risk measure estimated here.

  8. Multi-Channel Maximum Likelihood Pitch Estimation

    DEFF Research Database (Denmark)

    Christensen, Mads Græsbøll

    2012-01-01

    In this paper, a method for multi-channel pitch estimation is proposed. The method is a maximum likelihood estimator and is based on a parametric model where the signals in the various channels share the same fundamental frequency but can have different amplitudes, phases, and noise characteristics....... This essentially means that the model allows for different conditions in the various channels, like different signal-to-noise ratios, microphone characteristics and reverberation. Moreover, the method does not assume that a certain array structure is used but rather relies on a more general model and is hence...

  9. Conductivity maximum in a charged colloidal suspension

    Energy Technology Data Exchange (ETDEWEB)

    Bastea, S

    2009-01-27

    Molecular dynamics simulations of a charged colloidal suspension in the salt-free regime show that the system exhibits an electrical conductivity maximum as a function of colloid charge. We attribute this behavior to two main competing effects: colloid effective charge saturation due to counterion 'condensation' and diffusion slowdown due to the relaxation effect. In agreement with previous observations, we also find that the effective transported charge is larger than the one determined by the Stern layer and suggest that it corresponds to the boundary fluid layer at the surface of the colloidal particles.

  10. Dynamical maximum entropy approach to flocking.

    Science.gov (United States)

    Cavagna, Andrea; Giardina, Irene; Ginelli, Francesco; Mora, Thierry; Piovani, Duccio; Tavarone, Raffaele; Walczak, Aleksandra M

    2014-04-01

    We derive a new method to infer from data the out-of-equilibrium alignment dynamics of collectively moving animal groups, by considering the maximum entropy model distribution consistent with temporal and spatial correlations of flight direction. When bird neighborhoods evolve rapidly, this dynamical inference correctly learns the parameters of the model, while a static one relying only on the spatial correlations fails. When neighbors change slowly and the detailed balance is satisfied, we recover the static procedure. We demonstrate the validity of the method on simulated data. The approach is applicable to other systems of active matter.

  11. Maximum Temperature Detection System for Integrated Circuits

    Science.gov (United States)

    Frankiewicz, Maciej; Kos, Andrzej

    2015-03-01

    The paper describes structure and measurement results of the system detecting present maximum temperature on the surface of an integrated circuit. The system consists of the set of proportional to absolute temperature sensors, temperature processing path and a digital part designed in VHDL. Analogue parts of the circuit where designed with full-custom technique. The system is a part of temperature-controlled oscillator circuit - a power management system based on dynamic frequency scaling method. The oscillator cooperates with microprocessor dedicated for thermal experiments. The whole system is implemented in UMC CMOS 0.18 μm (1.8 V) technology.

  12. Maximum entropy PDF projection: A review

    Science.gov (United States)

    Baggenstoss, Paul M.

    2017-06-01

    We review maximum entropy (MaxEnt) PDF projection, a method with wide potential applications in statistical inference. The method constructs a sampling distribution for a high-dimensional vector x based on knowing the sampling distribution p(z) of a lower-dimensional feature z = T (x). Under mild conditions, the distribution p(x) having highest possible entropy among all distributions consistent with p(z) may be readily found. Furthermore, the MaxEnt p(x) may be sampled, making the approach useful in Monte Carlo methods. We review the theorem and present a case study in model order selection and classification for handwritten character recognition.

  13. Multiperiod Maximum Loss is time unit invariant.

    Science.gov (United States)

    Kovacevic, Raimund M; Breuer, Thomas

    2016-01-01

    Time unit invariance is introduced as an additional requirement for multiperiod risk measures: for a constant portfolio under an i.i.d. risk factor process, the multiperiod risk should equal the one period risk of the aggregated loss, for an appropriate choice of parameters and independent of the portfolio and its distribution. Multiperiod Maximum Loss over a sequence of Kullback-Leibler balls is time unit invariant. This is also the case for the entropic risk measure. On the other hand, multiperiod Value at Risk and multiperiod Expected Shortfall are not time unit invariant.

  14. Maximum a posteriori decoder for digital communications

    Science.gov (United States)

    Altes, Richard A. (Inventor)

    1997-01-01

    A system and method for decoding by identification of the most likely phase coded signal corresponding to received data. The present invention has particular application to communication with signals that experience spurious random phase perturbations. The generalized estimator-correlator uses a maximum a posteriori (MAP) estimator to generate phase estimates for correlation with incoming data samples and for correlation with mean phases indicative of unique hypothesized signals. The result is a MAP likelihood statistic for each hypothesized transmission, wherein the highest value statistic identifies the transmitted signal.

  15. Improved Maximum Parsimony Models for Phylogenetic Networks.

    Science.gov (United States)

    Van Iersel, Leo; Jones, Mark; Scornavacca, Celine

    2018-05-01

    Phylogenetic networks are well suited to represent evolutionary histories comprising reticulate evolution. Several methods aiming at reconstructing explicit phylogenetic networks have been developed in the last two decades. In this article, we propose a new definition of maximum parsimony for phylogenetic networks that permits to model biological scenarios that cannot be modeled by the definitions currently present in the literature (namely, the "hardwired" and "softwired" parsimony). Building on this new definition, we provide several algorithmic results that lay the foundations for new parsimony-based methods for phylogenetic network reconstruction.

  16. Ancestral sequence reconstruction with Maximum Parsimony

    OpenAIRE

    Herbst, Lina; Fischer, Mareike

    2017-01-01

    One of the main aims in phylogenetics is the estimation of ancestral sequences based on present-day data like, for instance, DNA alignments. One way to estimate the data of the last common ancestor of a given set of species is to first reconstruct a phylogenetic tree with some tree inference method and then to use some method of ancestral state inference based on that tree. One of the best-known methods both for tree inference as well as for ancestral sequence inference is Maximum Parsimony (...

  17. Contaminated water treatment

    Science.gov (United States)

    Gormly, Sherwin J. (Inventor); Flynn, Michael T. (Inventor)

    2010-01-01

    Method and system for processing of a liquid ("contaminant liquid") containing water and containing urine and/or other contaminants in a two step process. Urine, or a contaminated liquid similar to and/or containing urine and thus having a relatively high salt and urea content is passed through an activated carbon filter to provide a resulting liquid, to remove most of the organic molecules. The resulting liquid is passed through a semipermeable membrane from a membrane first side to a membrane second side, where a fortified drink having a lower water concentration (higher osmotic potential) than the resulting liquid is positioned. Osmotic pressure differential causes the water, but not most of the remaining inorganic (salts) contaminant(s) to pass through the membrane to the fortified drink. Optionally, the resulting liquid is allowed to precipitate additional organic molecules before passage through the membrane.

  18. Bioremediation of contaminated soil

    International Nuclear Information System (INIS)

    Balba, M.T.; Ying, A.C.; McNeice, T.G.

    1992-01-01

    Microorganisms, especially bacteria, yeast and fungi are capable of degrading many kinds of xenobiotic compounds and toxic chemicals such as petroleum hydrocarbon compounds. These microorganisms are ubiquitous in nature and, despite their enormous versatility, there are numerous cases in which long-term contamination of soil and groundwater has been observed. The persistence of the contamination is usually caused by the inability of microorganisms to metabolize these compounds under the prevailing environmental condition. This paper reports on biological remediation of contaminated sites which can be accomplished by using naturally-occurring microorganisms to treat the contaminants. The development of a bioremediation program for a specific contaminated soil system usually includes: A thorough site/soil/waste characterization; Treatability studies

  19. Contamination sources, prevention, and research

    Science.gov (United States)

    Contamination is defined as anything other than cotton in cotton lint. Worldwide, contamination is on the rise and plastic contamination has increased at a faster rate than contamination overall. In the U.S., there are many sources of plastic contaminants, such as plastic trash that collects in cott...

  20. Fumonisin B1 contamination in breast milk and its exposure in infants under 6 months of age in Rombo, Northern Tanzania.

    Science.gov (United States)

    Magoha, Happy; De Meulenaer, Bruno; Kimanya, Martin; Hipolite, Danstan; Lachat, Carl; Kolsteren, Patrick

    2014-12-01

    The carry-over of fumonisin B1 from contaminated feed into dairy milk also suggests its carry-over from contaminated food into breast milk. This study assessed fumonisin B1 contamination in breast milk and associated exposures of infants under 6 months of age. Breast milk samples were collected from 131 lactating mothers and the weight of their infants was measured during the first month of lactation. Fumonisin B1 was extracted using methanol:acetone, cleaned up with Strong Anion Exchange columns and quantified by HPLC. Fumonisin B1 exposure in each child was estimated using deterministic approach. Out of the 131 samples, 58 (44.3%) contained fumonisin B1 at levels ranging from 6.57 to 471.05 ng/ml. Of the contaminated samples, 10.3% had fumonisin B1 levels above the EU limit of 200 ppb for fumonisins in infants' food. Exposure in the infants ranged from 0.78 to 64.93 µg/kg body weight (bw) per day (median, 3 µg/kg bw/day) and exceeded the provisional maximum tolerable limit of 2 µg/kg bw/day in 29% of the infants. In conclusion, breast milk from mothers in Northern Tanzania is contaminated with fumonisins at levels that lead to unacceptable exposures in infants. Strategies to prevent lactating mothers from fumonisin exposure are urgently needed to minimise fumonisin exposure in infants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Sensitivity to contamination of optical coatings

    International Nuclear Information System (INIS)

    Macleod, A.

    1999-01-01

    A simple theory is presented of the sensitivity to contamination of optical coatings, which permits prediction of performance degradation in the presence of small deposit s of absorbing material. Although a major objective is the ability to compare the sensitivities of different coating types, absolute values can be made possible by adopting a standard contamination layer consisting of a 1 Angstrom thickness of carbon. Results are quoted for a number of common thin-film coatings and filters and are sometimes surprising. The common high-reflectance coating is the quarterwave stack and, at its reference wavelength, it has very low sensitivity to contamination. Although minor constructional errors have little effect on the reflectance, they can seriously affect the contamination sensitivity. Further, the level of contamination determines the maximum reflectance it is possible to achieve, regardless of the number of layers in the coating. The admittance diagram helps in understanding the reasons for the very large variations in sensitivity between coatings with quite similar reflectance

  2. Remediation of lead-contaminated soils

    International Nuclear Information System (INIS)

    Peters, R.W.; Shem, L.

    1992-01-01

    Excavation and transport of soil contaminated with heavy metals has generally been the standard remediation technique for treatment of heavy-metal-contaminated soils. This approach is not a permanent solution; moreover, off-site shipment and disposal of contaminated soil involves high expense, liability, and appropriate regulatory approval. Recently, a number of other techniques have been investigated for treating such contaminated sites, including flotation, solidification/stabilization, vitrification, and chemical extraction. This paper reports the results of a laboratory investigation determining the efficiency of using chelating agents to extract lead from contaminated soils. Lead concentrations in the soils ranged from 500 to 10,000 mg/kg. Ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) were examined for their potential extractive capabilities. Concentrations of the chelating agents ranged from 0.01 to 0.10 M. The pH of the suspensions in which the extractions were performed ranged from 4 to 12. Results showed that the removal of lead using NTA and water was ph-dependent, whereas the removal of lead using EDTA was ph-insensitive. Maximum removals of lead were 68.7%,19.1%, and 7.3% using EDTA, NTA, and water, respectively (as compared with initial lead concentrations)

  3. Control of everyday contamination problems in a hot cell laboratory

    International Nuclear Information System (INIS)

    Buch, R.

    1983-01-01

    For handling unsealed radioactive materials, contamination monitoring and the application of appropriate methods for the prevention of contamination are essential measures to achieve radiation protection safety at the working place and during operation. It is essential to know which are the contamination sources and which circumstances may lead to contamination release and diffusion. Depending on the kind of contamination and the extent of the resulting radiation exposure, suitable easy-to-use measuring equipment is necessary. The lecture shows how contamination release can be limited or prevented, and detected in due time by the use of appropriate measuring instruments, so that contaminations and the ways of decontaminating do not necessarily cause increased dose rates. (orig.) [de

  4. Thermodynamic limit for coherence-limited solar power conversion

    Science.gov (United States)

    Mashaal, Heylal; Gordon, Jeffrey M.

    2014-09-01

    The spatial coherence of solar beam radiation is a key constraint in solar rectenna conversion. Here, we present a derivation of the thermodynamic limit for coherence-limited solar power conversion - an expansion of Landsberg's elegant basic bound, originally limited to incoherent converters at maximum flux concentration. First, we generalize Landsberg's work to arbitrary concentration and angular confinement. Then we derive how the values are further lowered for coherence-limited converters. The results do not depend on a particular conversion strategy. As such, they pertain to systems that span geometric to physical optics, as well as classical to quantum physics. Our findings indicate promising potential for solar rectenna conversion.

  5. Objective Bayesianism and the Maximum Entropy Principle

    Directory of Open Access Journals (Sweden)

    Jon Williamson

    2013-09-01

    Full Text Available Objective Bayesian epistemology invokes three norms: the strengths of our beliefs should be probabilities; they should be calibrated to our evidence of physical probabilities; and they should otherwise equivocate sufficiently between the basic propositions that we can express. The three norms are sometimes explicated by appealing to the maximum entropy principle, which says that a belief function should be a probability function, from all those that are calibrated to evidence, that has maximum entropy. However, the three norms of objective Bayesianism are usually justified in different ways. In this paper, we show that the three norms can all be subsumed under a single justification in terms of minimising worst-case expected loss. This, in turn, is equivalent to maximising a generalised notion of entropy. We suggest that requiring language invariance, in addition to minimising worst-case expected loss, motivates maximisation of standard entropy as opposed to maximisation of other instances of generalised entropy. Our argument also provides a qualified justification for updating degrees of belief by Bayesian conditionalisation. However, conditional probabilities play a less central part in the objective Bayesian account than they do under the subjective view of Bayesianism, leading to a reduced role for Bayes’ Theorem.

  6. Efficient heuristics for maximum common substructure search.

    Science.gov (United States)

    Englert, Péter; Kovács, Péter

    2015-05-26

    Maximum common substructure search is a computationally hard optimization problem with diverse applications in the field of cheminformatics, including similarity search, lead optimization, molecule alignment, and clustering. Most of these applications have strict constraints on running time, so heuristic methods are often preferred. However, the development of an algorithm that is both fast enough and accurate enough for most practical purposes is still a challenge. Moreover, in some applications, the quality of a common substructure depends not only on its size but also on various topological features of the one-to-one atom correspondence it defines. Two state-of-the-art heuristic algorithms for finding maximum common substructures have been implemented at ChemAxon Ltd., and effective heuristics have been developed to improve both their efficiency and the relevance of the atom mappings they provide. The implementations have been thoroughly evaluated and compared with existing solutions (KCOMBU and Indigo). The heuristics have been found to greatly improve the performance and applicability of the algorithms. The purpose of this paper is to introduce the applied methods and present the experimental results.

  7. Bioremediation of petroleum contaminated soil

    International Nuclear Information System (INIS)

    Autry, A.R.; Ellis, G.M.

    1992-01-01

    This paper reports on bioremediation, which offers a cost-competitive, effective remediation alternative for soil contaminated with petroleum products. These technologies involve using microorganisms to biologically degrade organic constituents in contaminated soil. All bioremediation applications must mitigate various environmental rate limiting factors so that the biodegradation rates for petroleum hydrocarbons are optimized in field-relevant situations. Traditional bioremediation applications include landfarming, bioreactors, and composting. A more recent bioremediation application that has proven successful involves excavation of contaminated soil. The process involves the placement of the soils into a powerscreen, where it is screened to remove rocks and larger debris. The screened soil is then conveyed to a ribbon blender, where it is mixed in batch with nutrient solution containing nitrogen, phosphorus, water, and surfactants. Each mixed soil batch is then placed in a curing pile, where it remains undisturbed for the remainder of the treatment process, during which time biodegradation by naturally occurring microorganisms, utilizing biochemical pathways mediated by enzymes, will occur

  8. 41 CFR 101-26.507-4 - Quantities in excess of the maximum order limitation.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Quantities in excess of... Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS SUPPLY AND PROCUREMENT 26-PROCUREMENT SOURCES AND PROGRAM 26.5-GSA Procurement Programs § 101-26.507-4 Quantities in...

  9. Pushing desalination recovery to the maximum limit: Membrane and thermal processes integration

    KAUST Repository

    Shahzad, Muhammad Wakil; Burhan, Muhammad; Ng, Kim Choon

    2017-01-01

    The economics of seawater desalination processes has been continuously improving as a result of desalination market expansion. Presently, reverse osmosis (RO) processes are leading in global desalination with 53% share followed by thermally driven

  10. Pushing desalination recovery to the maximum limit: Membrane and thermal processes integration

    KAUST Repository

    Shahzad, Muhammad Wakil

    2017-05-05

    The economics of seawater desalination processes has been continuously improving as a result of desalination market expansion. Presently, reverse osmosis (RO) processes are leading in global desalination with 53% share followed by thermally driven technologies 33%, but in Gulf Cooperation Council (GCC) countries their shares are 42% and 56% respectively due to severe feed water quality. In RO processes, intake, pretreatment and brine disposal cost 25% of total desalination cost at 30–35% recovery. We proposed a tri-hybrid system to enhance overall recovery up to 81%. The conditioned brine leaving from RO processes supplied to proposed multi-evaporator adsorption cycle driven by low temperature industrial waste heat sources or solar energy. RO membrane simulation has been performed using WinFlow and IMSDesign commercial softwares developed by GE and Nitto. Detailed mathematical model of overall system is developed and simulation has been conducted in FORTRAN. The final brine reject concentration from tri-hybrid cycle can vary from 166,000ppm to 222,000ppm if RO retentate concentration varies from 45,000ppm to 60,000ppm. We also conducted economic analysis and showed that the proposed tri-hybrid cycle can achieve highest recovery, 81%, and lowest energy consumption, 1.76kWhelec/m3, for desalination reported in the literature up till now.

  11. Extracting maximum petrophysical and geological information from a limited reservoir database

    Energy Technology Data Exchange (ETDEWEB)

    Ali, M.; Chawathe, A.; Ouenes, A. [New Mexico Institute of Mining and Technology, Socorro, NM (United States)] [and others

    1997-08-01

    The characterization of old fields lacking sufficient core and log data is a challenging task. This paper describes a methodology that uses new and conventional tools to build a reliable reservoir model for the Sulimar Queen field. At the fine scale, permeability measured on a fine grid with a minipermeameter was used in conjunction with the petrographic data collected on multiple thin sections. The use of regression analysis and a newly developed fuzzy logic algorithm led to the identification of key petrographic elements which control permeability. At the log scale, old gamma ray logs were first rescaled/calibrated throughout the entire field for consistency and reliability using only four modem logs. Using data from one cored well and the rescaled gamma ray logs, correlations between core porosity, permeability, total water content and gamma ray were developed to complete the small scale characterization. At the reservoir scale, outcrop data and the rescaled gamma logs were used to define the reservoir structure over an area of ten square miles where only 36 wells were available. Given the structure, the rescaled gamma ray logs were used to build the reservoir volume by identifying the flow units and their continuity. Finally, history-matching results constrained to the primary production were used to estimate the dynamic reservoir properties such as relative permeabilities to complete the characterization. The obtained reservoir model was tested by forecasting the waterflood performance and which was in good agreement with the actual performance.

  12. Leveraging Limited Scope for Maximum Benefit in Occupied Renovation of Uninsulated Cold Climate Multifamily Housing

    Energy Technology Data Exchange (ETDEWEB)

    Neuhauser, K. [Building Science Corporation (BSC), Somer, MA (United States); Bergey, D. [Building Science Corporation (BSC), Somer, MA (United States); Osser, R. [Building Science Corporation (BSC), Somer, MA (United States)

    2012-03-01

    This project examines a large-scale renovation project within a 500 unit, 1960's era subsidized urban housing community. This research focuses on the airflow control and window replacement measures implemented as part of the renovations to the low-rise apartment buildings. The window replacement reduced the nominal conductive loss of the apartment enclosure by approximately 15%; air sealing measures reduced measured air leakage by approximately 40% on average.

  13. Ion permeability of the cytoplasmic membrane limits the maximum growth temperature of bacteria and archaea

    NARCIS (Netherlands)

    van de Vossenberg, J.L C M; Ubbink-Kok, T.; Elferink, M.G.L.; Driessen, A.J.M.; Konings, W.N

    1995-01-01

    Protons and sodium ions are the most commonly used coupling ions in energy transduction in bacteria and archaea. At their growth temperature, the permeability of the cytoplasmic membrane of thermophilic bacteria to protons is high compared with that of sodium ions. In some thermophiles, sodium is

  14. Barge Train Maximum Impact Forces Using Limit States for the Lashings Between Barges

    National Research Council Canada - National Science Library

    Arroyo, Jose R; Ebeling, Robert M

    2005-01-01

    ... on: the mass including hydrodynamic added mass of the barge train, the approach velocity, the approach angle, the barge train moment of inertia, damage sustained by the barge structure, and friction...

  15. 75 FR 76482 - Federal Housing Administration (FHA): FHA Maximum Loan Limits for 2011

    Science.gov (United States)

    2010-12-08

    ... http://www.hud.gov/offices/adm/hudclips/letters/mortgagee/ . FOR FURTHER INFORMATION CONTACT: Karin B... be found at http://www.hud.gov/offices/adm/hudclips/letters/mortgagee/ mortgagee/. Dated: November 29...

  16. Some biological aspects in acoustic contamination

    International Nuclear Information System (INIS)

    Palacio B, Jaime

    1996-01-01

    For an appropriate diagnosis of the environmental quality of the aquatic ecosystems, the aspects physic chemicals and biotic should be conjugated and to identify the processes of natural origin and anthropogenic. Any study based on a partial vision that excludes a holistic treatment of the problem, limits the possibilities of interpretation of the data and the quality of the results. The aquatic biota acts as a natural monitor, because it responds in an integral form to the changes under the environmental conditions. Among the procedures for investigation of the biological effects of the deterioration of the quality of the natural waters, the toxicity rehearsals have acquired a growing importance in the last years, like base for the formulation of permissible maximum concentrations. In the aquatic toxicology, the tests of sharp toxicity and chronicle are those most broadly diffused ones. One of the most frequent critics to the rehearsals of sharp toxicity is that the high concentrations of toxic substances employees lower laboratory conditions; they are not common in the natural atmospheres. Nevertheless, these tests allow to locate the main contamination sources and to apply factors for the estimate of levels of security. The approach more employee to evaluate the sharp toxic effects of a xeno-biotic, is the concentration lethal stocking (CL50) For the calculation of the CL50 it has intended several forms that include techniques graphic simple or computational model based on the use of transformations. The procedure more applied in Colombia for the computation of the CL50 is the graphic method of Litchfield - Wilcoxon (1949). Starting from statistical considerations the employment of graphic techniques is not recommended and model computational should only be used that allow the estimate of the intervals of trust of the CL50

  17. Absorption-Edge-Modulated Transmission Spectra for Water Contaminant Monitoring

    Science.gov (United States)

    2016-03-31

    Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6390--16-9675 Absorption- Edge -Modulated Transmission Spectra for Water Contaminant...ABSTRACT c. THIS PAGE 18. NUMBER OF PAGES 17. LIMITATION OF ABSTRACT Absorption- Edge -Modulated Transmission Spectra for Water Contaminant Monitoring...contaminants, within a volume of sampled solution, requires sufficient sensitivity. The present study examines the sensitivity of absorption- edge

  18. Development of irradiation technique on controlling food contamination residue

    International Nuclear Information System (INIS)

    Liu Bin; Xiong Shanbai; Xiong Guangquan; Cheng Wei; Chen Yuxia; Liao Tao; Li Xin; Lin Ruotai

    2010-01-01

    The current state of the researches of irradiation technology on controlling food mycotoxin, pesticide, veterinary drugs and fishery drugs residue was summarized. And the degradation rate, mechanism, products and toxicities of food contamination were expatiated. The free radical from irradiation attack the site of weaker bond, and the less or more toxic substances were produced, which lead to the degradation of the food contamination. The limitations and future application of irradiation technique on controlling food contamination were also analyzed. (authors)

  19. Investigation of internal contamination by tritium in A-1 nuclear power plant personnel in 1974

    International Nuclear Information System (INIS)

    Ondris, D.; Herchl, M.; Homolova, E.

    1977-01-01

    The results are presented of the 1974 personnel monitoring of the Bohunice A-1 nuclear power plant staff for internal contamination with tritium. Totally, 650 urine samples taken from 103 workers were analyzed using the recommended ICRP procedure. In routine examinations, the highest dose equivalent value of tritium incorporated within two weeks did not exceed 10 mrem, i.e., the maximum annual dose equivalent did not exceed 260 mrem. 8.5 μCi tritium per 1 litre urine was considered to be an alarm value. In a selected group of 21 high-risk persons analyses were conducted before and after each operation associated with tritium hazards. The limit dose was set to 5.8 μCi.l -1 , i.e., the tritium concentration equivalent to 10% of the maximum permissible annual intake. In 18 workers where tritium risk was of a more serious nature the biological half-life was followed up, with the average biological half-life being 8.5 days, with 5 days for the minimum and 12 days for the maximum values. The results show that in 1974 the tritium burden did not exceed 1/10 of the maximum permissible dose for any of the A-1 nuclear power plant workers. (L.O.)

  20. Subsurface contaminants focus area

    International Nuclear Information System (INIS)

    1996-08-01

    The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites

  1. Direct contamination - seasonality

    International Nuclear Information System (INIS)

    Aarkrog, A.

    1994-01-01

    Direct contamination is the primary pathway to terrestrial vegetation in the first period after an activity release to the atmosphere. All radionuclides are able to be transferred via this pathway. Deposition, interception and retention are the three processes involved in direct contamination of crops. Wet deposition is more important than dry deposition in temperature regions. Resuspension and rainsplash both belong to secondary direct deposition and became evident for e.g. radiocaesium after the Chernobyl accident. Seasonality is the varying response to radioactive contamination of crops according to the time of the year when the contamination occurs. Shortlived radionuclides (as 131 I) and those that mainly enter the foodchain by direct contamination (e.g. 137 Cs) are especially important in this connection. In particular, the contamination of cereal crops is influenced by seasonality. As a result of seasonality the impact of the Chernobyl accident on the radioactive contamination of human diet was for the same deposition density higher in southern than in northern Europe. (orig.)

  2. Subsurface contaminants focus area

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites.

  3. Analogue of Pontryagin's maximum principle for multiple integrals minimization problems

    OpenAIRE

    Mikhail, Zelikin

    2016-01-01

    The theorem like Pontryagin's maximum principle for multiple integrals is proved. Unlike the usual maximum principle, the maximum should be taken not over all matrices, but only on matrices of rank one. Examples are given.

  4. Lake Basin Fetch and Maximum Length/Width

    Data.gov (United States)

    Minnesota Department of Natural Resources — Linear features representing the Fetch, Maximum Length and Maximum Width of a lake basin. Fetch, maximum length and average width are calcuated from the lake polygon...

  5. Does modifying personal responsibility moderate the mental contamination effect?

    Science.gov (United States)

    Kennedy, Tinisha S; Simonds, Laura M

    2017-12-01

    Mental contamination is the psychological sense of internal dirtiness that arises in the absence of physical contact with a perceived contaminant. Mental contamination can be evoked through imagining perpetrating a moral transgression. This study experimentally evoked mental contamination by asking men to imagine perpetrating a non-consensual kiss. It explored whether reducing sense of personal responsibility for the kiss moderated the mental contamination effect. Male students (N = 60) imagined giving either a consensual or non-consensual kiss. Personal responsibility for the kiss was manipulated in one of two non-consensual kiss conditions by way of the inclusion of social influence information. Feelings of mental contamination were assessed by self-report and through a behavioural index. Mental contamination was successfully induced in the two non-consensual kiss conditions. There was evidence to support the hypothesis that reducing personal responsibility might moderate specific components of mental contamination (shame, dirtiness and urge to cleanse). The effect of responsibility modification was evident in the self-report measures, but not in the behavioural index. The sample comprised male university students which limits generalizability of the findings. The behavioural assessment of mental contamination was limited to a proxy measure. Imagined moral violations are associated with increases in indices of mental contamination. Further research should investigate whether feelings of shame, dirtiness and urge to cleanse are particularly responsive to responsibility modifications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Uniaxial compression tests on diesel contaminated frozen silty soil specimens

    International Nuclear Information System (INIS)

    Chenaf, D.; Stampli, N.; Bathurst, R.; Chapuis, R.P.

    1999-01-01

    Results of a uniaxial, unconfined compression test on artificial diesel-contaminated and uncontaminated frozen silty soils are discussed. The testing program involved 59 specimens. The results show that for the same fluid content, diesel contamination reduced the strength of the frozen specimens by increasing the unfrozen water content. For example, in specimens containing 50 per cent diesel oil of the fluid content by weight the maximum strength was reduced by 95 per cent compared to the strength of an uncontaminated specimen. Diesel contamination was also shown to contribute to the slippage between soil particles by acting as a lubricant, thus accelerating the loss of compressive strength.13 refs., 18 figs

  7. Maximum Likelihood Reconstruction for Magnetic Resonance Fingerprinting.

    Science.gov (United States)

    Zhao, Bo; Setsompop, Kawin; Ye, Huihui; Cauley, Stephen F; Wald, Lawrence L

    2016-08-01

    This paper introduces a statistical estimation framework for magnetic resonance (MR) fingerprinting, a recently proposed quantitative imaging paradigm. Within this framework, we present a maximum likelihood (ML) formalism to estimate multiple MR tissue parameter maps directly from highly undersampled, noisy k-space data. A novel algorithm, based on variable splitting, the alternating direction method of multipliers, and the variable projection method, is developed to solve the resulting optimization problem. Representative results from both simulations and in vivo experiments demonstrate that the proposed approach yields significantly improved accuracy in parameter estimation, compared to the conventional MR fingerprinting reconstruction. Moreover, the proposed framework provides new theoretical insights into the conventional approach. We show analytically that the conventional approach is an approximation to the ML reconstruction; more precisely, it is exactly equivalent to the first iteration of the proposed algorithm for the ML reconstruction, provided that a gridding reconstruction is used as an initialization.

  8. Maximum Profit Configurations of Commercial Engines

    Directory of Open Access Journals (Sweden)

    Yiran Chen

    2011-06-01

    Full Text Available An investigation of commercial engines with finite capacity low- and high-price economic subsystems and a generalized commodity transfer law [n ∝ Δ (P m] in commodity flow processes, in which effects of the price elasticities of supply and demand are introduced, is presented in this paper. Optimal cycle configurations of commercial engines for maximum profit are obtained by applying optimal control theory. In some special cases, the eventual state—market equilibrium—is solely determined by the initial conditions and the inherent characteristics of two subsystems; while the different ways of transfer affect the model in respects of the specific forms of the paths of prices and the instantaneous commodity flow, i.e., the optimal configuration.

  9. The worst case complexity of maximum parsimony.

    Science.gov (United States)

    Carmel, Amir; Musa-Lempel, Noa; Tsur, Dekel; Ziv-Ukelson, Michal

    2014-11-01

    One of the core classical problems in computational biology is that of constructing the most parsimonious phylogenetic tree interpreting an input set of sequences from the genomes of evolutionarily related organisms. We reexamine the classical maximum parsimony (MP) optimization problem for the general (asymmetric) scoring matrix case, where rooted phylogenies are implied, and analyze the worst case bounds of three approaches to MP: The approach of Cavalli-Sforza and Edwards, the approach of Hendy and Penny, and a new agglomerative, "bottom-up" approach we present in this article. We show that the second and third approaches are faster than the first one by a factor of Θ(√n) and Θ(n), respectively, where n is the number of species.

  10. Radioactive contamination of foodstuffs: determination of permissible levels; Contamination radioactive des denrees alimentaires: determination des niveaux admissibles

    Energy Technology Data Exchange (ETDEWEB)

    Ledermann, S [Commissariat a l' Energie Atomique, Fontenay- aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    In a latent air-soil contamination situation, the population would receive 80 per cent of its contamination through foodstuffs. The supervision of this food poses many problems: sampling, radionuclide dosages, etc. It is also necessary to estimate the maximum permissible concentration of radionuclides in foodstuffs, once the maximum exposure limit for the human body has been fixed. The passage of this level to the maximum concentrations is not simple since a) each radionuclide has its own particular effect on the body; b) their concentrations vary from one foodstuff to another, and c) the average amounts of foodstuffs vary from one population to another. Two methods are given here for estimating the maximum permissible concentrations in foodstuffs, together with the first diets likely to become critical when several of them are to be considered simultaneously. The results depend on the way in which the present situation can change to become critical. This evolutionary path can only be estimated approximately. Two methods are therefore given for studying the sensitivity of the results. As an example, a numerical application of these methods using data actually available is given. The data used is naturally incomplete and this will always be true. This application test indicates however two fields in which an improvement is absolutely necessary. 1 - The obtention of multiple observations (simultaneous dosage of at least 2 radionuclides in the same foodstuff, and simultaneous dosage of at least two foodstuffs for the same radionuclide); this assumes a combined effort by the various organisms; 2 - The reaching of an agreement on the dosage methods used by the various organisms since the results actually available are not comparable. (authors) [French] Dans une situation de contamination air-sol latente, la contamination des populations se ferait a 80 pour cent par l'alimentation. Surveiller cette alimentation pose des problemes complexes: echantillonnage, dosage des

  11. Safety against radioactive contamination

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The ALWIT anticontamination suit is briefly described, consisting of lasting antistatic ''NDMEX III''. It was specially developed for the fire brigade who are exposed to a particular kind of contamination while carrying out radiation measurements during fire fighting, rescue and clearing up work. The ALWIT suit reliably prevents radioactive contamination of the surface of the body while wearing a breathing apparatus, independent of the ambient air. Tightly fitting cuffs on the neck, arms and legs together with zippers placed behind prevent contamination even with extreme movement. (P.F.K.)

  12. Modelling maximum likelihood estimation of availability

    International Nuclear Information System (INIS)

    Waller, R.A.; Tietjen, G.L.; Rock, G.W.

    1975-01-01

    Suppose the performance of a nuclear powered electrical generating power plant is continuously monitored to record the sequence of failure and repairs during sustained operation. The purpose of this study is to assess one method of estimating the performance of the power plant when the measure of performance is availability. That is, we determine the probability that the plant is operational at time t. To study the availability of a power plant, we first assume statistical models for the variables, X and Y, which denote the time-to-failure and the time-to-repair variables, respectively. Once those statistical models are specified, the availability, A(t), can be expressed as a function of some or all of their parameters. Usually those parameters are unknown in practice and so A(t) is unknown. This paper discusses the maximum likelihood estimator of A(t) when the time-to-failure model for X is an exponential density with parameter, lambda, and the time-to-repair model for Y is an exponential density with parameter, theta. Under the assumption of exponential models for X and Y, it follows that the instantaneous availability at time t is A(t)=lambda/(lambda+theta)+theta/(lambda+theta)exp[-[(1/lambda)+(1/theta)]t] with t>0. Also, the steady-state availability is A(infinity)=lambda/(lambda+theta). We use the observations from n failure-repair cycles of the power plant, say X 1 , X 2 , ..., Xsub(n), Y 1 , Y 2 , ..., Ysub(n) to present the maximum likelihood estimators of A(t) and A(infinity). The exact sampling distributions for those estimators and some statistical properties are discussed before a simulation model is used to determine 95% simulation intervals for A(t). The methodology is applied to two examples which approximate the operating history of two nuclear power plants. (author)

  13. Maximum T/sub c/: optimistic evidence

    International Nuclear Information System (INIS)

    Dynes, R.C.; Allen, P.B.

    1976-01-01

    A reanalysis of Eliashberg theory in the strong coupling limit and the relationship between the superconducting transition temperature T/sub c/ of a material and its normal state properties is presented. At weak and intermediate coupling (lambda approx. 2 >)/sup 1 / 2 /. The lambda = 2 limit predicted by McMillan disappears in the correct theory because it is a result of the functional dependence of T/sub c/ on lambda and used by McMillan which is valid only if lamba 2 (ω)F(ω) for values of lambda < or = 1.5

  14. The Maximum Flux of Star-Forming Galaxies

    Science.gov (United States)

    Crocker, Roland M.; Krumholz, Mark R.; Thompson, Todd A.; Clutterbuck, Julie

    2018-04-01

    The importance of radiation pressure feedback in galaxy formation has been extensively debated over the last decade. The regime of greatest uncertainty is in the most actively star-forming galaxies, where large dust columns can potentially produce a dust-reprocessed infrared radiation field with enough pressure to drive turbulence or eject material. Here we derive the conditions under which a self-gravitating, mixed gas-star disc can remain hydrostatic despite trapped radiation pressure. Consistently taking into account the self-gravity of the medium, the star- and dust-to-gas ratios, and the effects of turbulent motions not driven by radiation, we show that galaxies can achieve a maximum Eddington-limited star formation rate per unit area \\dot{Σ }_*,crit ˜ 10^3 M_{⊙} pc-2 Myr-1, corresponding to a critical flux of F*, crit ˜ 1013L⊙ kpc-2 similar to previous estimates; higher fluxes eject mass in bulk, halting further star formation. Conversely, we show that in galaxies below this limit, our one-dimensional models imply simple vertical hydrostatic equilibrium and that radiation pressure is ineffective at driving turbulence or ejecting matter. Because the vast majority of star-forming galaxies lie below the maximum limit for typical dust-to-gas ratios, we conclude that infrared radiation pressure is likely unimportant for all but the most extreme systems on galaxy-wide scales. Thus, while radiation pressure does not explain the Kennicutt-Schmidt relation, it does impose an upper truncation on it. Our predicted truncation is in good agreement with the highest observed gas and star formation rate surface densities found both locally and at high redshift.

  15. 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

  16. Understanding arsenic contamination of groundwater in Bangladesh

    International Nuclear Information System (INIS)

    Kabir, Babar

    2001-01-01

    The problem of water contamination by naturally occurring arsenic confronts governments, public and private utilities, and the development community with a new challenge for implementing operational mitigation activities under difficult conditions of imperfect knowledge - especially for arsenic mitigation for the benefit of the rural poor. With more than a conservative estimate of 20 million of its 130 million people assumed to be drinking contaminated water and another 70 million potentially at risk, Bangladesh is facing what has been described as perhaps the largest mass poisoning in history. High concentrations of naturally occurring arsenic have already been found in water from tens of thousands of tube wells, the main source of potable water, in 59 out of Bangladesh's 64 districts. Arsenic contamination is highly irregular, so tube wells in neighboring locations or even different depths can be safe. Arsenic is extremely hazardous if ingested in drinking water or used in cooking in excess of the maximum permissible limit of 0.01 mg/liter over an extended period of time. Even in the early 1970s, most of Bangladesh's rural population got its drinking water from surface ponds and nearly a quarter of a million children died each year from water-borne diseases. Groundwater now constitutes the major source of drinking water in Bangladesh with 95% of the drinking water coming from underground sources. The provision of tube well water for 97 percent of the rural population has been credited with bringing down the high incidence of diarrheal diseases and contributing to a halving of the infant mortality rate. Paradoxically, the same wells that saved so many lives now pose a threat due to the unforeseen hazard of arsenic. The provenance of arsenic rich minerals in sediments of the Bengal basin as a component of geological formations is believed to be from the Himalayan mountain range. Arsenic has been found in different uncropped geological hard rock formations

  17. On-site radioactive soil contamination at the Andreeva Bay shore technical base, Northwest Russia.

    Science.gov (United States)

    Reistad, O; Dowdall, M; Selnaes, Ø G; Standring, W J F; Hustveit, S; Steenhuisen, F; Sørlie, A

    2008-07-01

    The radioactive waste (RAW) storage site at Andreeva Bay in the Russian Northwest has experienced radioactive contamination both as a result of activities carried out at the site and due to incidents that have occurred there in the past such as accidental releases of radioactive materials. The site is an interesting case study for decommissioning due to the extremely large amounts of radioactivity present at the site and the conditions under which it is stored; very little has been previously published in the scientific literature about this site. This paper complements the paper describing dose rates at Andreeva Bay which is published in this issue of Journal of Environmental Radioactivity by the same authors. This study presents new data related to the activity concentrations of (137)Cs and (90)Sr in surface soils and measurements of alpha- and beta-particle fluxes taken at different areas around the site. Limited data on 60Co is also presented. The results of the study indicate that the main areas of site contamination are associated with the former spent nuclear fuel storage facility at Building 5, due to accidental discharges which began in 1982. Substantial contamination is also observed at the solid radioactive waste storage facilities, probably due to the ingress of water into these facilities. More than 240 samples were measured: maximum contamination levels were 1 x 10(6)Bq/kg (137)Cs (mean value 4.1 x 10(5)Bq/kg) and 4 x 10(6)Bq/kg (90)Sr (mean value 1.2 x1 0(5)Bq/kg). Localised patches of alpha and beta contamination were also observed throughout the site.

  18. Estimation of Maximum Allowable PV Connection to LV Residential Power Networks

    DEFF Research Database (Denmark)

    Demirok, Erhan; Sera, Dezso; Teodorescu, Remus

    2011-01-01

    Maximum photovoltaic (PV) hosting capacity of low voltage (LV) power networks is mainly restricted by either thermal limits of network components or grid voltage quality resulted from high penetration of distributed PV systems. This maximum hosting capacity may be lower than the available solar...... potential of geographic area due to power network limitations even though all rooftops are fully occupied with PV modules. Therefore, it becomes more of an issue to know what exactly limits higher PV penetration level and which solutions should be engaged efficiently such as over sizing distribution...

  19. Radio contamination control on imported food. The bilberry case

    International Nuclear Information System (INIS)

    Zappa, S.; Calabrese, M.; Stancher, B.

    2001-01-01

    In this paper was pointed out the European regulation concerning the permissible limits of 137 Cs contamination in food importation, from countries affected by the consequences of the Chernobyl accident of 1986. A discussion about the control systems is lead and original data concerning the importation of the fruits of bilberry, a species particularly sensitive to radio contamination, are reported [it

  20. Heavy metal contamination in stream water and sediments of gold ...

    African Journals Online (AJOL)

    I.O.OLABANJI

    3D) with 0.457 ± 0.061 and 0.364 ± 0.056 mg/L in dry and wet seasons. The mean .... safe limit clearly indicating that Cd contamination of the stream water might be ... of lead contaminant in the study area is the formation of acid mine drainage.

  1. Cleanup of contaminated areas

    International Nuclear Information System (INIS)

    Beone, G.; Carbone, A.I.; Zagaroli, M.

    1989-01-01

    The paper deals with the problem of contaminated areas cleanup, in order to eliminate every possible damage for man safety and environment and to site recovery for some utilization, The first step of cleanup operation is site characterization, that is followed by a pianificazion activity for a better definition of staff qualification, technology to be used, protection and prevention instruments for the risks due to contaminants handling. The second section describes the different remedial technologies for contaminated sites. Remedial technologies may be divided into on-site/off-site and in-situ treatments, according to whether materials (waste, soil, water) are moved to another location or not, respectively. Finally, it is outlined that contaminated areas cleanup is a typical multidisciplinary activity because very different competences are required. (author)

  2. Contaminant Candidate List 2

    Data.gov (United States)

    U.S. Environmental Protection Agency — CCL 2 is a list of contaminants that are currently not subject to any proposed or promulgated national primary drinking water regulations, that are known or...

  3. Contaminant Candidate List 3

    Data.gov (United States)

    U.S. Environmental Protection Agency — CCL 3 is a list of contaminants that are currently not subject to any proposed or promulgated national primary drinking water regulations, that are known or...

  4. Contaminant Candidate List 1

    Data.gov (United States)

    U.S. Environmental Protection Agency — CCL 1 is a list of contaminants that are currently not subject to any proposed or promulgated national primary drinking water regulations, that are known or...

  5. Tracers Detect Aquifer Contamination

    National Research Council Canada - National Science Library

    Enfield, Carl

    1995-01-01

    The EPA's National Laboratory (NRMRL) at Ada, OK, along with the University of Florida and the University of Texas, have developed a tracer procedure to detect the amount of contamination in aquifer formations...

  6. A maximum power point tracking for photovoltaic-SPE system using a maximum current controller

    Energy Technology Data Exchange (ETDEWEB)

    Muhida, Riza [Osaka Univ., Dept. of Physical Science, Toyonaka, Osaka (Japan); Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Park, Minwon; Dakkak, Mohammed; Matsuura, Kenji [Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Tsuyoshi, Akira; Michira, Masakazu [Kobe City College of Technology, Nishi-ku, Kobe (Japan)

    2003-02-01

    Processes to produce hydrogen from solar photovoltaic (PV)-powered water electrolysis using solid polymer electrolysis (SPE) are reported. An alternative control of maximum power point tracking (MPPT) in the PV-SPE system based on the maximum current searching methods has been designed and implemented. Based on the characteristics of voltage-current and theoretical analysis of SPE, it can be shown that the tracking of the maximum current output of DC-DC converter in SPE side will track the MPPT of photovoltaic panel simultaneously. This method uses a proportional integrator controller to control the duty factor of DC-DC converter with pulse-width modulator (PWM). The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment. (Author)

  7. Monitoring of transport contamination

    International Nuclear Information System (INIS)

    Turkin, N.F.

    1980-01-01

    Organization of monitoring of transport contamination is considered. A particularly thorough monitoring is recommended to be carried out in loading-unloading operations. The monitoring is performed when leaving loading-unloading site and zone under control and prior to preventive examination, technical service or repair. The method of monitoring of auto transport contamination with high-energy β-emitters by means of a special stand permitting the automation of the monitoring process is described [ru

  8. Degradation of myocardial perfusion SPECT images caused by contaminants in thallous (201Tl) chloride

    International Nuclear Information System (INIS)

    Staelens, Steven G.; Wit, Tim C. de; Lemahieu, Ignace A.; Beekman, Freek J.

    2008-01-01

    Thallous ( 201 Tl) chloride is a single-photon emission computed tomography (SPECT) tracer mainly used for assessing perfusion and viability of myocardial tissue. 201 Tl emits X-rays around 72 keV and gammas at 167 keV, and has a half-life of 73 h. Regulations allow an intrinsic contamination up to 3-5%, which is mainly caused by 200 Tl (368 keV; 26 h) and by 202 Tl (439 keV; 12.2 days). Contra-intuitive to the low-level percentages in which these contaminants are present, their impact may be significant because of much higher gamma camera sensitivity for these high-energy photon emissions. Therefore, we investigate the effects of the contaminants in terms of detected fractions of photons in projections and contrast degradation in reconstructed images. Acquisitions of a digital thorax phantom filled with thallous ( 201 Tl) chloride were simulated with a validated Monte Carlo tool, thereby, modelling 1% of contamination by 200 Tl and 202 Tl each. In addition, measurements of a thorax phantom on a dual-headed gamma camera were performed. The product used was contaminated by 0.17% of 200 Tl and 0.24% of 202 Tl at activity reference time (ART). This ART is specified by the manufacturer, thereby, accounting for the difference in half-lives of 201 Tl and its contaminants. These measurements were repeated at different dates associated with various contamination levels. Simulations showed that, with 1% of 200 Tl and 202 Tl, the total contamination in the 72 keV window can rise up to one out of three detected photons. For the 167keV window, the contamination is even more pronounced: more than four out of five detections in this photopeak window originate from contaminants. Measurements indicate that cold lesion contrast in myocardial perfusion SPECT imaging is at maximum close to ART. In addition to a higher noise level, relative contrast decreases 15% 2 days early to ART, which is explained by an increase in 200 Tl contamination. After ART, contrast decreased by 16% when

  9. Reconditioning contaminated gravel

    International Nuclear Information System (INIS)

    Walsh, H.; Bowers, J.S.; Cadwell, K.

    1995-02-01

    Lawrence Livermore National Laboratory (LLNL) has developed a portable screening system that will recondition radioactively contaminated gravel in the field. The separation technique employed by this system removes dirt, contaminated debris, and other fine particles from gravel. At LLNL, gravel is used in conjunction with the experimental testing of explosives to reduce shock wave propagation. The gravel surrounds the experimental device and buffers the energy generated from the explosion. During an explosion, some of the gravel is broken down into small particles and mixed with contaminants. Contaminants in the used gravel originate from metal sheathing and other parts comprising, the experimental device. These contaminants may consist of radionuclides and metals that are considered hazardous by the State of California when disposed. This paper describes the process that conveys contaminated material into the screener system, sprays the material with recycled water or other mild cleaning chemicals, and separates particles based on size. Particles greater than a specified size are discharged out of the screener separator and recycled back into use, thereby reducing the amount of mixed waste generated and minimizing the need for new gravel. The fines or silt are flushed out of the separator with the water and are removed from the water and consolidated into a drum with the use of a hydrocyclone separator and drum decant system. Because the water in the spray system is recycled, minimal makeup water is needed. The system monitors pH and total dissolved solids

  10. Real significance of skin contamination is

    International Nuclear Information System (INIS)

    Sudmann, R.H.

    1983-01-01

    For five decades, health physicists have discussed the thickness, area, significance of radioactive contamination and the exposures to various portions of the skin. Concern about instances of skin contamination extend beyond the resultant organ dose simply because it is a recognizable and quantifiable event. As such, there is a tendency for management and regulatory agencies to use it as a trend indicator. The final result is a score card similar to the list of OSHA reportable accidents. In fact, the skin contamination incidence rate has a somewhat different meaning to the health physicist, to the manager, and to the regulator. The question must then be asked, What is the true significance of skin contamination, Is it the resultant skin dose, Is it an indicator of loss of control, Is it both or neither. In order to answer these questions, Rockwell Hanford Operations began analysis of the previous five years records of skin contamination cases. Since by policy each incidence of skin contamination is documented, a large percentage of the 425 records analyzed were of low level activity (less than 100 dpm/cm 2 ) on the extremeties, primarily hands and fingers. Most of these cases were readily decontaminated with soap and water. Individual elements studied included: detection/monitoring methods and limits; impact of type of operation on the incidence rate; causes of and methods for reduction of the incidence rate; reporting and documentation; and dose assessment. Results of the study indicate that skin contamination rarely presents a beta dose problem because it is normally highly localized on the extremeties. Only in unusual cases does it represent a potential for internal deposition. Thus, the real importance of skin contamination incidence is as an indicator of deteriorating conditions and should be reviewed by health physicists, managers and regulators as such

  11. Maximum/minimum asymmetric rod detection

    International Nuclear Information System (INIS)

    Huston, J.T.

    1990-01-01

    This patent describes a system for determining the relative position of each control rod within a control rod group in a nuclear reactor. The control rod group having at least three control rods therein. It comprises: means for producing a signal representative of a position of each control rod within the control rod group in the nuclear reactor; means for establishing a signal representative of the highest position of a control rod in the control rod group in the nuclear reactor; means for establishing a signal representative of the lowest position of a control rod in the control rod group in the nuclear reactor; means for determining a difference between the signal representative of the position of the highest control rod and the signal representative of the position of the lowest control rod; means for establishing a predetermined limit for the difference between the signal representative of the position of the highest control rod and the signal representative of the position of the lowest control rod; and means for comparing the difference between the signals with the predetermined limit. The comparing means producing an output signal when the difference between the signals exceeds the predetermined limit

  12. TRENDS IN ESTIMATED MIXING DEPTH DAILY MAXIMUMS

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R; Amy DuPont, A; Robert Kurzeja, R; Matt Parker, M

    2007-11-12

    Mixing depth is an important quantity in the determination of air pollution concentrations. Fireweather forecasts depend strongly on estimates of the mixing depth as a means of determining the altitude and dilution (ventilation rates) of smoke plumes. The Savannah River United States Forest Service (USFS) routinely conducts prescribed fires at the Savannah River Site (SRS), a heavily wooded Department of Energy (DOE) facility located in southwest South Carolina. For many years, the Savannah River National Laboratory (SRNL) has provided forecasts of weather conditions in support of the fire program, including an estimated mixing depth using potential temperature and turbulence change with height at a given location. This paper examines trends in the average estimated mixing depth daily maximum at the SRS over an extended period of time (4.75 years) derived from numerical atmospheric simulations using two versions of the Regional Atmospheric Modeling System (RAMS). This allows for differences to be seen between the model versions, as well as trends on a multi-year time frame. In addition, comparisons of predicted mixing depth for individual days in which special balloon soundings were released are also discussed.

  13. Mammographic image restoration using maximum entropy deconvolution

    International Nuclear Information System (INIS)

    Jannetta, A; Jackson, J C; Kotre, C J; Birch, I P; Robson, K J; Padgett, R

    2004-01-01

    An image restoration approach based on a Bayesian maximum entropy method (MEM) has been applied to a radiological image deconvolution problem, that of reduction of geometric blurring in magnification mammography. The aim of the work is to demonstrate an improvement in image spatial resolution in realistic noisy radiological images with no associated penalty in terms of reduction in the signal-to-noise ratio perceived by the observer. Images of the TORMAM mammographic image quality phantom were recorded using the standard magnification settings of 1.8 magnification/fine focus and also at 1.8 magnification/broad focus and 3.0 magnification/fine focus; the latter two arrangements would normally give rise to unacceptable geometric blurring. Measured point-spread functions were used in conjunction with the MEM image processing to de-blur these images. The results are presented as comparative images of phantom test features and as observer scores for the raw and processed images. Visualization of high resolution features and the total image scores for the test phantom were improved by the application of the MEM processing. It is argued that this successful demonstration of image de-blurring in noisy radiological images offers the possibility of weakening the link between focal spot size and geometric blurring in radiology, thus opening up new approaches to system optimization

  14. Maximum Margin Clustering of Hyperspectral Data

    Science.gov (United States)

    Niazmardi, S.; Safari, A.; Homayouni, S.

    2013-09-01

    In recent decades, large margin methods such as Support Vector Machines (SVMs) are supposed to be the state-of-the-art of supervised learning methods for classification of hyperspectral data. However, the results of these algorithms mainly depend on the quality and quantity of available training data. To tackle down the problems associated with the training data, the researcher put effort into extending the capability of large margin algorithms for unsupervised learning. One of the recent proposed algorithms is Maximum Margin Clustering (MMC). The MMC is an unsupervised SVMs algorithm that simultaneously estimates both the labels and the hyperplane parameters. Nevertheless, the optimization of the MMC algorithm is a non-convex problem. Most of the existing MMC methods rely on the reformulating and the relaxing of the non-convex optimization problem as semi-definite programs (SDP), which are computationally very expensive and only can handle small data sets. Moreover, most of these algorithms are two-class classification, which cannot be used for classification of remotely sensed data. In this paper, a new MMC algorithm is used that solve the original non-convex problem using Alternative Optimization method. This algorithm is also extended for multi-class classification and its performance is evaluated. The results of the proposed algorithm show that the algorithm has acceptable results for hyperspectral data clustering.

  15. Paving the road to maximum productivity.

    Science.gov (United States)

    Holland, C

    1998-01-01

    "Job security" is an oxymoron in today's environment of downsizing, mergers, and acquisitions. Workers find themselves living by new rules in the workplace that they may not understand. How do we cope? It is the leader's charge to take advantage of this chaos and create conditions under which his or her people can understand the need for change and come together with a shared purpose to effect that change. The clinical laboratory at Arkansas Children's Hospital has taken advantage of this chaos to down-size and to redesign how the work gets done to pave the road to maximum productivity. After initial hourly cutbacks, the workers accepted the cold, hard fact that they would never get their old world back. They set goals to proactively shape their new world through reorganizing, flexing staff with workload, creating a rapid response laboratory, exploiting information technology, and outsourcing. Today the laboratory is a lean, productive machine that accepts change as a way of life. We have learned to adapt, trust, and support each other as we have journeyed together over the rough roads. We are looking forward to paving a new fork in the road to the future.

  16. Maximum power flux of auroral kilometric radiation

    International Nuclear Information System (INIS)

    Benson, R.F.; Fainberg, J.

    1991-01-01

    The maximum auroral kilometric radiation (AKR) power flux observed by distant satellites has been increased by more than a factor of 10 from previously reported values. This increase has been achieved by a new data selection criterion and a new analysis of antenna spin modulated signals received by the radio astronomy instrument on ISEE 3. The method relies on selecting AKR events containing signals in the highest-frequency channel (1980, kHz), followed by a careful analysis that effectively increased the instrumental dynamic range by more than 20 dB by making use of the spacecraft antenna gain diagram during a spacecraft rotation. This analysis has allowed the separation of real signals from those created in the receiver by overloading. Many signals having the appearance of AKR harmonic signals were shown to be of spurious origin. During one event, however, real second harmonic AKR signals were detected even though the spacecraft was at a great distance (17 R E ) from Earth. During another event, when the spacecraft was at the orbital distance of the Moon and on the morning side of Earth, the power flux of fundamental AKR was greater than 3 x 10 -13 W m -2 Hz -1 at 360 kHz normalized to a radial distance r of 25 R E assuming the power falls off as r -2 . A comparison of these intense signal levels with the most intense source region values (obtained by ISIS 1 and Viking) suggests that multiple sources were observed by ISEE 3

  17. Maximum likelihood window for time delay estimation

    International Nuclear Information System (INIS)

    Lee, Young Sup; Yoon, Dong Jin; Kim, Chi Yup

    2004-01-01

    Time delay estimation for the detection of leak location in underground pipelines is critically important. Because the exact leak location depends upon the precision of the time delay between sensor signals due to leak noise and the speed of elastic waves, the research on the estimation of time delay has been one of the key issues in leak lovating with the time arrival difference method. In this study, an optimal Maximum Likelihood window is considered to obtain a better estimation of the time delay. This method has been proved in experiments, which can provide much clearer and more precise peaks in cross-correlation functions of leak signals. The leak location error has been less than 1 % of the distance between sensors, for example the error was not greater than 3 m for 300 m long underground pipelines. Apart from the experiment, an intensive theoretical analysis in terms of signal processing has been described. The improved leak locating with the suggested method is due to the windowing effect in frequency domain, which offers a weighting in significant frequencies.

  18. Ancestral Sequence Reconstruction with Maximum Parsimony.

    Science.gov (United States)

    Herbst, Lina; Fischer, Mareike

    2017-12-01

    One of the main aims in phylogenetics is the estimation of ancestral sequences based on present-day data like, for instance, DNA alignments. One way to estimate the data of the last common ancestor of a given set of species is to first reconstruct a phylogenetic tree with some tree inference method and then to use some method of ancestral state inference based on that tree. One of the best-known methods both for tree inference and for ancestral sequence inference is Maximum Parsimony (MP). In this manuscript, we focus on this method and on ancestral state inference for fully bifurcating trees. In particular, we investigate a conjecture published by Charleston and Steel in 1995 concerning the number of species which need to have a particular state, say a, at a particular site in order for MP to unambiguously return a as an estimate for the state of the last common ancestor. We prove the conjecture for all even numbers of character states, which is the most relevant case in biology. We also show that the conjecture does not hold in general for odd numbers of character states, but also present some positive results for this case.

  19. 49 CFR 230.24 - Maximum allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

  20. 20 CFR 226.52 - Total annuity subject to maximum.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Total annuity subject to maximum. 226.52... COMPUTING EMPLOYEE, SPOUSE, AND DIVORCED SPOUSE ANNUITIES Railroad Retirement Family Maximum § 226.52 Total annuity subject to maximum. The total annuity amount which is compared to the maximum monthly amount to...

  1. Half-width at half-maximum, full-width at half-maximum analysis

    Indian Academy of Sciences (India)

    addition to the well-defined parameter full-width at half-maximum (FWHM). The distribution of ... optical side-lobes in the diffraction pattern resulting in steep central maxima [6], reduc- tion of effects of ... and broad central peak. The idea of.

  2. The unintended energy impacts of increased nitrate contamination from biofuels production.

    Science.gov (United States)

    Twomey, Kelly M; Stillwell, Ashlynn S; Webber, Michael E

    2010-01-01

    Increases in corn cultivation for biofuels production, due to the Energy Independence and Security Act of 2007, are likely to lead to increases in nitrate concentrations in both surface and groundwater resources in the United States. These increases might trigger the requirement for additional energy consumption for water treatment to remove the nitrates. While these increasing concentrations of nitrate might pose a human health concern, most water resources were found to be within current maximum contaminant level (MCL) limits of 10 mg L(-1) NO(3)-N. When water resources exceed this MCL, energy-intensive drinking water treatment is required to reduce nitrate levels below 10 mg L(-1). Based on prior estimates of water supplies currently exceeding the nitrate MCL, we calculate that advanced drinking water treatment might require an additional 2360 million kWh annually (for nitrate affected areas only)--a 2100% increase in energy requirements for water treatment in those same areas--to mitigate nitrate contamination and meet the MCL requirement. We predict that projected increases in nitrate contamination in water may impact the energy consumed in the water treatment sector, because of the convergence of several related trends: (1) increasing cornstarch-based ethanol production, (2) increasing nutrient loading in surface water and groundwater resources as a consequence of increased corn-based ethanol production, (3) additional drinking water sources that exceed the MCL for nitrate, and (4) potentially more stringent drinking water standards for nitrate.

  3. Development of automatic smear testing sampler for radioactive contamination of floor in nuclear power plant

    International Nuclear Information System (INIS)

    Nozawa, Katsuro; Hashimoto, Hiroshi; Shinohara, Yohtaro; Iwaki, Kiyotaka

    1980-01-01

    The floor contamination with radioactive substances in the controlled area of nuclear power stations is strictly controlled, and it is tested by the smear method, wiping the contaminants on floors with filter papers or cloths and measuring the radioactive intensity to obtain contamination density. The works are very laborious, therefore the automatic smear sampler was developed. Simple operation, shortening of time required for wiping, constant and high efficiency of wiping, and easy numbering of samples were the aims in the development. The method of wiping, the mechanisms of wiping, cloth feeding and running, the surface pressure at the time of wiping, the number of times of wiping and required motor torque were studied. The outline of the developed sampler is explained. The performance of the sampler was compared with manual wiping. The efficiency of wiping with the sampler was 92%, assuming manual wiping as 100. Difference was not observed between careful manual wiping and the wiping with the sampler, therefore it was confirmed that this automatic floor smear sampler can be put in practical use. By conventional manual sampling, the maximum limit was about 400 samples/man-day, but when this sampler is used, about 1000 samples/sampler-day is possible. At present, this sampler is operated in Hamaoka Nuclear Power Station. (Kako, I.)

  4. EFFECTS OF COMPACTIVE EFFORTS ON GEOTECHNICAL PROPERTIES OF SPENT ENGINE OIL CONTAMINATED LATERITE SOIL

    Directory of Open Access Journals (Sweden)

    OLUREMI, J. ROTIMI

    2017-03-01

    Full Text Available Investigation of the effects of compactive efforts and spent engine oil (SEO contamination on the geotechnical properties of lateritic soils was made. Contaminated specimens were prepared by mixing lateritic soil with up to 10 % SEO by dry weight of the soil in step concentration of 2 % and subjected to geotechnical tests. Results indicated a decrease in the fine content, decrease in liquid limit, maximum dry density (MDD and unconfined compressive strength (UCS with up to 10 % SEO content. No general trend was observed in the optimum moisture content (OMC with increasing SEO content. The MDD, OMC and UCS values increased with increase in the compactive effort. Regression analysis of the results showed that optimum moisture content, fine content and compactive effort significantly influence the soils UCS values. Analysis of variance showed that SEO and compactive effort has significant effect on the parameters with the exception in one case. The results of laboratory tests showed that geotechnical properties of the SEO contaminated soil were immensely impaired.

  5. Exposure and bioavailability of arsenic in contaminated soils from the La Parrilla mine, Spain

    Science.gov (United States)

    Anawar, H. M.; Garcia-Sanchez, A.; Murciego, A.; Buyolo, T.

    2006-05-01

    Arsenic derived from mining activity may contaminate water, soil and plant ecosystems resulting in human health and ecotoxicological risks. In this study, exposure assessment of arsenic (As) in soil, spoil, pondwater and plants collected from the areas contaminated by mine tailings and spoils in and around the La Parrilla mine, Caceres province, Spain, was carried out using AAS method. Water solubility, bioavailability and soil-plant transfer coefficients of As and phytoremediation potential of plants were determined. Arsenic concentrations varied from 148 to 2,540 mg/kg in soils of site 1 and from 610 to 1,285 mg/kg in site 2 exceeding the guideline limit for agricultural soil (50 mg/kg). Arsenic concentrations in pond waters varied from 8.8 to 101.4 μg/l. High concentrations of water-soluble As in the soils that ranged from 0.10 to 4.71 mg/kg in site 1 and from 0.46 to 4.75 mg/kg in site 2 exceeded the maximum permitted level of water-soluble As (0.04 mg/kg) in agricultural soils. Arsenic concentrations varied from 0.8 to 149.5 mg/kg dry wt in the plants of site 1 and from 2.0 to 10.0 mg/kg in the plants of site 2. Arsenic concentrations in plants increased in the approximate order: Retama sphaerocarpa phytoremediation of As contaminated soils.

  6. Survey of radioactive contamination for foodstuffs

    International Nuclear Information System (INIS)

    Lee, Wan No; Lee, Chang Wu; Choi, Geun Sik; Cho, Yeong Hyeon; Kang, Mun Ja; Cheong, Geun Ho; Kim, Hui Ryeong; Park, Du Won; Park, Hyo Guk; Kwak, Ji Yeon

    2006-11-01

    After the Chernobyl nuclear accident in 1986, a lot of countries including EU, Japan, USA are to strengthen survey of radioactive contamination for foodstuffs. Our country has also surveyed radioactive contamination of the imported foodstuffs and started to check continuously the radioactivity contamination of the open market foodstuffs since 2003. In this year, imported foodstuffs(130 samples) and domestic foodstuffs(10 samples) are analyzed to investigate the radioactive contamination. Sampled foodstuffs items are collected from the open markets; one group is the imported foodstuffs and the other group is the domestic foodstuffs producted around nuclear facilities and northeast of Sokcho city concerning recent situations. Samples are usually bought from traditional markets, mart, department store or the Internet. After pretreatments such as drying, ashing, and homogenization, all samples were analyzed by gamma spectrometer system for survey and assessment of radioactive contamination. The 131 I radionuclide isn't detected among all foodstuffs(imported and domestic). The 137 Cs radionuclide among the regulation radionuclides( 137 Cs, 13 4 C s, 131 I) of food code is only detected at the imported foodstuffs but its level is far below the maximum permitted level. For the improvement of measurement confidence, the developed analysis method is tested by the participation of the national and international intercomparison. The developed method based on test results and international standard would be used at radioactive analysis as well as an education of relative workers. It could be applied as the basis data for amending the analysis method of food code. It is technically supported for radioactive analysis of commercial company and the government including KFDA. Finally these results would be used to solve an ambiguous anxiety of a people for radiation exposure by foodstuffs intake and help the KFDA to manage systematically the radioactive contamination and to give

  7. Maximum-likelihood estimation of recent shared ancestry (ERSA).

    Science.gov (United States)

    Huff, Chad D; Witherspoon, David J; Simonson, Tatum S; Xing, Jinchuan; Watkins, W Scott; Zhang, Yuhua; Tuohy, Therese M; Neklason, Deborah W; Burt, Randall W; Guthery, Stephen L; Woodward, Scott R; Jorde, Lynn B

    2011-05-01

    Accurate estimation of recent shared ancestry is important for genetics, evolution, medicine, conservation biology, and forensics. Established methods estimate kinship accurately for first-degree through third-degree relatives. We demonstrate that chromosomal segments shared by two individuals due to identity by descent (IBD) provide much additional information about shared ancestry. We developed a maximum-likelihood method for the estimation of recent shared ancestry (ERSA) from the number and lengths of IBD segments derived from high-density SNP or whole-genome sequence data. We used ERSA to estimate relationships from SNP genotypes in 169 individuals from three large, well-defined human pedigrees. ERSA is accurate to within one degree of relationship for 97% of first-degree through fifth-degree relatives and 80% of sixth-degree and seventh-degree relatives. We demonstrate that ERSA's statistical power approaches the maximum theoretical limit imposed by the fact that distant relatives frequently share no DNA through a common ancestor. ERSA greatly expands the range of relationships that can be estimated from genetic data and is implemented in a freely available software package.

  8. Maximum surface level and temperature histories for Hanford waste tanks

    International Nuclear Information System (INIS)

    Flanagan, B.D.; Ha, N.D.; Huisingh, J.S.

    1994-01-01

    Radioactive defense waste resulting from the chemical processing of spent nuclear fuel has been accumulating at the Hanford Site since 1944. This waste is stored in underground waste-storage tanks. The Hanford Site Tank Farm Facilities Interim Safety Basis (ISB) provides a ready reference to the safety envelope for applicable tank farm facilities and installations. During preparation of the ISB, tank structural integrity concerns were identified as a key element in defining the safety envelope. These concerns, along with several deficiencies in the technical bases associated with the structural integrity issues and the corresponding operational limits/controls specified for conduct of normal tank farm operations are documented in the ISB. Consequently, a plan was initiated to upgrade the safety envelope technical bases by conducting Accelerated Safety Analyses-Phase 1 (ASA-Phase 1) sensitivity studies and additional structural evaluations. The purpose of this report is to facilitate the ASA-Phase 1 studies and future analyses of the single-shell tanks (SSTs) and double-shell tanks (DSTs) by compiling a quantitative summary of some of the past operating conditions the tanks have experienced during their existence. This report documents the available summaries of recorded maximum surface levels and maximum waste temperatures and references other sources for more specific data

  9. Application of maximum values for radiation exposure and principles for the calculation of radiation doses

    International Nuclear Information System (INIS)

    2007-08-01

    The guide presents the definitions of equivalent dose and effective dose, the principles for calculating these doses, and instructions for applying their maximum values. The limits (Annual Limit on Intake and Derived Air Concentration) derived from dose limits are also presented for the purpose of monitoring exposure to internal radiation. The calculation of radiation doses caused to a patient from medical research and treatment involving exposure to ionizing radiation is beyond the scope of this ST Guide

  10. Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

    Science.gov (United States)

    Hall, Alex; Taylor, Andy

    2017-06-01

    We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with promising results. We find that the introduction of an intrinsic shape prior can help with mitigation of noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely subdominant. We show how biases propagate to shear estimates, demonstrating in our simple set-up that shear biases can be reduced by orders of magnitude and potentially to within the requirements of planned space-based surveys at mild signal-to-noise ratio. We find that second-order terms can exhibit significant cancellations at low signal-to-noise ratio when Gaussian noise is assumed, which has implications for inferring the performance of shear-measurement algorithms from simplified simulations. We discuss the viability of our point estimators as tools for lensing inference, arguing that they allow for the robust measurement of ellipticity and shear.

  11. Preliminary attempt on maximum likelihood tomosynthesis reconstruction of DEI data

    International Nuclear Information System (INIS)

    Wang Zhentian; Huang Zhifeng; Zhang Li; Kang Kejun; Chen Zhiqiang; Zhu Peiping

    2009-01-01

    Tomosynthesis is a three-dimension reconstruction method that can remove the effect of superimposition with limited angle projections. It is especially promising in mammography where radiation dose is concerned. In this paper, we propose a maximum likelihood tomosynthesis reconstruction algorithm (ML-TS) on the apparent absorption data of diffraction enhanced imaging (DEI). The motivation of this contribution is to develop a tomosynthesis algorithm in low-dose or noisy circumstances and make DEI get closer to clinic application. The theoretical statistical models of DEI data in physics are analyzed and the proposed algorithm is validated with the experimental data at the Beijing Synchrotron Radiation Facility (BSRF). The results of ML-TS have better contrast compared with the well known 'shift-and-add' algorithm and FBP algorithm. (authors)

  12. Attitude sensor alignment calibration for the solar maximum mission

    Science.gov (United States)

    Pitone, Daniel S.; Shuster, Malcolm D.

    1990-01-01

    An earlier heuristic study of the fine attitude sensors for the Solar Maximum Mission (SMM) revealed a temperature dependence of the alignment about the yaw axis of the pair of fixed-head star trackers relative to the fine pointing Sun sensor. Here, new sensor alignment algorithms which better quantify the dependence of the alignments on the temperature are developed and applied to the SMM data. Comparison with the results from the previous study reveals the limitations of the heuristic approach. In addition, some of the basic assumptions made in the prelaunch analysis of the alignments of the SMM are examined. The results of this work have important consequences for future missions with stringent attitude requirements and where misalignment variations due to variations in the temperature will be significant.

  13. Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

    Science.gov (United States)

    Markley, F. Landis; Reynolds, Reid G.; Liu, Frank X.; Lebsock, Kenneth L.

    2009-01-01

    Spacecraft reaction wheel maneuvers are limited by the maximum torque and/or angular momentum that the wheels can provide. For an n-wheel configuration, the torque or momentum envelope can be obtained by projecting the n-dimensional hypercube, representing the domain boundary of individual wheel torques or momenta, into three dimensional space via the 3xn matrix of wheel axes. In this paper, the properties of the projected hypercube are discussed, and algorithms are proposed for determining this maximal torque or momentum envelope for general wheel configurations. Practical strategies for distributing a prescribed torque or momentum among the n wheels are presented, with special emphasis on configurations of four, five, and six wheels.

  14. Maximum Recoverable Gas from Hydrate Bearing Sediments by Depressurization

    KAUST Repository

    Terzariol, Marco

    2017-11-13

    The estimation of gas production rates from hydrate bearing sediments requires complex numerical simulations. This manuscript presents a set of simple and robust analytical solutions to estimate the maximum depressurization-driven recoverable gas. These limiting-equilibrium solutions are established when the dissociation front reaches steady state conditions and ceases to expand further. Analytical solutions show the relevance of (1) relative permeabilities between the hydrate free sediment, the hydrate bearing sediment, and the aquitard layers, and (2) the extent of depressurization in terms of the fluid pressures at the well, at the phase boundary, and in the far field. Close form solutions for the size of the produced zone allow for expeditious financial analyses; results highlight the need for innovative production strategies in order to make hydrate accumulations an economically-viable energy resource. Horizontal directional drilling and multi-wellpoint seafloor dewatering installations may lead to advantageous production strategies in shallow seafloor reservoirs.

  15. Statistic method of research reactors maximum permissible power calculation

    International Nuclear Information System (INIS)

    Grosheva, N.A.; Kirsanov, G.A.; Konoplev, K.A.; Chmshkyan, D.V.

    1998-01-01

    The technique for calculating maximum permissible power of a research reactor at which the probability of the thermal-process accident does not exceed the specified value, is presented. The statistical method is used for the calculations. It is regarded that the determining function related to the reactor safety is the known function of the reactor power and many statistically independent values which list includes the reactor process parameters, geometrical characteristics of the reactor core and fuel elements, as well as random factors connected with the reactor specific features. Heat flux density or temperature is taken as a limiting factor. The program realization of the method discussed is briefly described. The results of calculating the PIK reactor margin coefficients for different probabilities of the thermal-process accident are considered as an example. It is shown that the probability of an accident with fuel element melting in hot zone is lower than 10 -8 1 per year for the reactor rated power [ru

  16. A silicon pad shower maximum detector for a Shashlik calorimeter

    International Nuclear Information System (INIS)

    Alvsvaag, S.J.; Maeland, O.A.; Klovning, A.

    1995-01-01

    The new luminosity monitor of the DELPHI detector, STIC (Small angle TIle Calorimeter), was built using a Shashlik technique. This technique does not provide longitudinal sampling of the showers, which limits the measurement of the direction of the incident particles and the e-π separation. For these reasons STIC was equipped with a Silicon Pad Shower Maximum Detector (SPSMD). In order to match the silicon detectors to the Shashlick read out by wavelength shifter (WLS) fibers, the silicon wafers had to be drilled with a precision better than 10μm without damaging the active area of the detectors. This paper describes the SPSMD with emphasis on the fabrication techniques and on the components used. Some preliminary results of the detector performance from data taken with a 45GeV electron beam at CERN are presented. (orig.)

  17. Using Elementary Mechanics to Estimate the Maximum Range of ICBMs

    Science.gov (United States)

    Amato, Joseph

    2018-04-01

    North Korea's development of nuclear weapons and, more recently, intercontinental ballistic missiles (ICBMs) has added a grave threat to world order. The threat presented by these weapons depends critically on missile range, i.e., the ability to reach North America or Europe while carrying a nuclear warhead. Using the limited information available from near-vertical test flights, how do arms control experts estimate the maximum range of an ICBM? The purpose of this paper is to show, using mathematics and concepts appropriate to a first-year calculus-based mechanics class, how a missile's range can be estimated from the (observable) altitude attained during its test flights. This topic—while grim—affords an ideal opportunity to show students how the application of basic physical principles can inform and influence public policy. For students who are already familiar with Kepler's laws, it should be possible to present in a single class period.

  18. Maximum Likelihood Blood Velocity Estimator Incorporating Properties of Flow Physics

    DEFF Research Database (Denmark)

    Schlaikjer, Malene; Jensen, Jørgen Arendt

    2004-01-01

    )-data under investigation. The flow physic properties are exploited in the second term, as the range of velocity values investigated in the cross-correlation analysis are compared to the velocity estimates in the temporal and spatial neighborhood of the signal segment under investigation. The new estimator...... has been compared to the cross-correlation (CC) estimator and the previously developed maximum likelihood estimator (MLE). The results show that the CMLE can handle a larger velocity search range and is capable of estimating even low velocity levels from tissue motion. The CC and the MLE produce...... for the CC and the MLE. When the velocity search range is set to twice the limit of the CC and the MLE, the number of incorrect velocity estimates are 0, 19.1, and 7.2% for the CMLE, CC, and MLE, respectively. The ability to handle a larger search range and estimating low velocity levels was confirmed...

  19. Application of the maximum entropy production principle to electrical systems

    International Nuclear Information System (INIS)

    Christen, Thomas

    2006-01-01

    For a simple class of electrical systems, the principle of the maximum entropy production rate (MaxEP) is discussed. First, we compare the MaxEP principle and the principle of the minimum entropy production rate and illustrate the superiority of the MaxEP principle for the example of two parallel constant resistors. Secondly, we show that the Steenbeck principle for the electric arc as well as the ohmic contact behaviour of space-charge limited conductors follow from the MaxEP principle. In line with work by Dewar, the investigations seem to suggest that the MaxEP principle can also be applied to systems far from equilibrium, provided appropriate information is available that enters the constraints of the optimization problem. Finally, we apply the MaxEP principle to a mesoscopic system and show that the universal conductance quantum, e 2 /h, of a one-dimensional ballistic conductor can be estimated

  20. 9,10-Anthraquinone deposit in tea plantation might be one of the reasons for contamination in tea.

    Science.gov (United States)

    Wang, Xuan; Zhou, Li; Luo, Fengjian; Zhang, Xinzhong; Sun, Hezhi; Yang, Mei; Lou, Zhengyun; Chen, Zongmao

    2018-04-01

    9,10-Anthraquinone (AQ) was a new contaminant, with unknown sources, occurred globally in tea. European Union (EU) fixed the maximum residue limit (MRL) of 0.02mg/kg. The pollution source of AQ in tea was traced from the view of AQ deposit on tea crop by simulation. The possible contamination pathway and main factors to decrease AQ were explored in tea cultivation- tea manufacture- tea infusion, on the basis of AQ analytical methods by using solvent extraction and gas chromatography-tandem mass spectrometry (GC-MS/MS) quantification. 58.8-84.6% of AQ degraded in tea processing, and drying played a key role to reduce the AQ contamination. Certain concentration of AQ deposited on tea shoots could resulted in AQ beyond the MRL of 0.02mg/kg in tea. AQ leaching into tea brew (about 10%) could lead to the possible health risk. AQ deposit on tea crop during the tea cultivation might cause the AQ contamination in tea. Copyright © 2017. Published by Elsevier Ltd.

  1. 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.

  2. Radioactive contamination of natural and artificial materials

    International Nuclear Information System (INIS)

    Kovalchuk, E.L.; Pomansky, A.A.; Smolnikov, A.A.; Temmoev, A.H.

    1980-01-01

    The gamma radiation of different materials was measured in an underground low-background chamber with extraordinary background characteristics. The excellent background conditions of the measurements enabled investigators to see the alpha-particle peaks of the internal radioactive contamination of NaI(Tl) detectors, which were especially made for these measurements. The sensitivity limit of the installation was determined by the internal contamination of the NaI(Tl) detectors alone. Any radiation background, except for three substances, tungsten, copper, and brass, could be registered

  3. A maximum likelihood framework for protein design

    Directory of Open Access Journals (Sweden)

    Philippe Hervé

    2006-06-01

    Full Text Available Abstract Background The aim of protein design is to predict amino-acid sequences compatible with a given target structure. Traditionally envisioned as a purely thermodynamic question, this problem can also be understood in a wider context, where additional constraints are captured by learning the sequence patterns displayed by natural proteins of known conformation. In this latter perspective, however, we still need a theoretical formalization of the question, leading to general and efficient learning methods, and allowing for the selection of fast and accurate objective functions quantifying sequence/structure compatibility. Results We propose a formulation of the protein design problem in terms of model-based statistical inference. Our framework uses the maximum likelihood principle to optimize the unknown parameters of a statistical potential, which we call an inverse potential to contrast with classical potentials used for structure prediction. We propose an implementation based on Markov chain Monte Carlo, in which the likelihood is maximized by gradient descent and is numerically estimated by thermodynamic integration. The fit of the models is evaluated by cross-validation. We apply this to a simple pairwise contact potential, supplemented with a solvent-accessibility term, and show that the resulting models have a better predictive power than currently available pairwise potentials. Furthermore, the model comparison method presented here allows one to measure the relative contribution of each component of the potential, and to choose the optimal number of accessibility classes, which turns out to be much higher than classically considered. Conclusion Altogether, this reformulation makes it possible to test a wide diversity of models, using different forms of potentials, or accounting for other factors than just the constraint of thermodynamic stability. Ultimately, such model-based statistical analyses may help to understand the forces

  4. Treatment of chromium contaminated soil using bioremediation

    Science.gov (United States)

    Purwanti, Ipung Fitri; Putri, Tesya Paramita; Kurniawan, Setyo Budi

    2017-11-01

    Chromium contamination in soil occurs due to the disposal of chromium industrial wastewater or sludge that excess the quality standard. Chromium concentration in soil is ranged between 1 to 300 mg/kg while the maximum health standard is 2.5 mg/kg. Bioremediation is one of technology that could be used for remediating heavy metal contamination in soil. Bacteria have an ability to remove heavy metal from soil. One bacteria species that capable to remove chromium from soil is Bacillus subtilis. The aim of this research was to know the chromium removal percentage in contaminated soil by Bacillus subtilis. Artificial chromium contaminated soil was used by mixing 425gram sand and chromium trichloride solution. Concentration of chromium added into the spiked soil were 50, 75, and 100 mg/L. During 14 days, pH, soil temperature and soil moisture were tested. Initial and final number of bacterial colony and chromium concentration analysed. The result showed that the highest percentage of chromium removal was 11% at a chromium concentration of 75 mg/L

  5. 7 CFR 3560.612 - Loan limits.

    Science.gov (United States)

    2010-01-01

    ... DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS On-Farm Labor Housing § 3560.612 Loan limits. The maximum loan amount will be 100 percent of the allowable total development costs of on-farm labor housing and...

  6. Maximum entropy principle and hydrodynamic models in statistical mechanics

    International Nuclear Information System (INIS)

    Trovato, M.; Reggiani, L.

    2012-01-01

    numerical density n and of the effective temperature T; ii) the results available from literature in the framework both of a quantum Boltzmann gas and a degenerate quantum Fermi gas are recovered as particular cases; iii) the statistics for the quantum Fermi and Bose gases at different levels of degeneracy are explicitly incorporated; iv) a set of relevant applications admitting exact analytical equations are explicitly given and discussed; v) the quantum maximum entropy principle keeps full validity in the classical limit, when ħ→→ 0. Future perspectives of the MEP, are briefly addressed.

  7. ON THE MAXIMUM MASS OF STELLAR BLACK HOLES

    International Nuclear Information System (INIS)

    Belczynski, Krzysztof; Fryer, Chris L.; Bulik, Tomasz; Ruiter, Ashley; Valsecchi, Francesca; Vink, Jorick S.; Hurley, Jarrod R.

    2010-01-01

    We present the spectrum of compact object masses: neutron stars and black holes (BHs) that originate from single stars in different environments. In particular, we calculate the dependence of maximum BH mass on metallicity and on some specific wind mass loss rates (e.g., Hurley et al. and Vink et al.). Our calculations show that the highest mass BHs observed in the Galaxy M bh ∼ 15 M sun in the high metallicity environment (Z = Z sun = 0.02) can be explained with stellar models and the wind mass loss rates adopted here. To reach this result we had to set luminous blue variable mass loss rates at the level of ∼10 -4 M sun yr -1 and to employ metallicity-dependent Wolf-Rayet winds. With such winds, calibrated on Galactic BH mass measurements, the maximum BH mass obtained for moderate metallicity (Z = 0.3 Z sun = 0.006) is M bh,max = 30 M sun . This is a rather striking finding as the mass of the most massive known stellar BH is M bh = 23-34 M sun and, in fact, it is located in a small star-forming galaxy with moderate metallicity. We find that in the very low (globular cluster-like) metallicity environment the maximum BH mass can be as high as M bh,max = 80 M sun (Z = 0.01 Z sun = 0.0002). It is interesting to note that X-ray luminosity from Eddington-limited accretion onto an 80 M sun BH is of the order of ∼10 40 erg s -1 and is comparable to luminosities of some known ultra-luminous X-ray sources. We emphasize that our results were obtained for single stars only and that binary interactions may alter these maximum BH masses (e.g., accretion from a close companion). This is strictly a proof-of-principle study which demonstrates that stellar models can naturally explain even the most massive known stellar BHs.

  8. Nanomaterial-enabled Rapid Detection of Water Contaminants.

    Science.gov (United States)

    Mao, Shun; Chang, Jingbo; Zhou, Guihua; Chen, Junhong

    2015-10-28

    Water contaminants, e.g., inorganic chemicals and microorganisms, are critical metrics for water quality monitoring and have significant impacts on human health and plants/organisms living in water. The scope and focus of this review is nanomaterial-based optical, electronic, and electrochemical sensors for rapid detection of water contaminants, e.g., heavy metals, anions, and bacteria. These contaminants are commonly found in different water systems. The importance of water quality monitoring and control demands significant advancement in the detection of contaminants in water because current sensing technologies for water contaminants have limitations. The advantages of nanomaterial-based sensing technologies are highlighted and recent progress on nanomaterial-based sensors for rapid water contaminant detection is discussed. An outlook for future research into this rapidly growing field is also provided. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Prevalence of Parasitic Contamination

    Science.gov (United States)

    Ismail, Yazan

    2016-01-01

    One of the main ways in transmitting parasites to humans is through consuming contaminated raw vegetables. The aim of this study was to evaluate the prevalence of parasitological contamination (helminthes eggs, Giardia and Entamoeba histolytica cysts) of salad vegetables sold at supermarkets and street vendors in Amman and Baqa’a – Jordan. A total of 133 samples of salad vegetables were collected and examined for the prevalence of parasites. It was found that 29% of the samples were contaminated with different parasites. Of the 30 lettuce, 33 tomato, 42 parsley and 28 cucumber samples examined the prevalence of Ascaris spp. eggs was 43%, 15%, 21% and 4%; Toxocara spp. eggs was 30%, 0%, 0% and 4%; Giardia spp. cysts was 23%, 6%, 0% and 0%; Taenia/Echinococcus eggs was 20%, 0%, 5% and 0%; Fasciola hepatica eggs was 13%, 3%, 2% and 0%; and E. histolytica cysts was 10%, 6%, 0% and 0%, respectively. There was no significant difference in the prevalence of parasite in salad vegetables either between supermarkets and street vendors, or between Amman and Baqa’a, Ascaris spp. was found to be the highest prevalent parasite in salad vegetables from supermarkets and street vendors and from Amman and Baqa’a. Our results pointed out that, the parasitic contamination of salad vegetables found in our study might be caused by irrigating crops with faecal contaminated water. We concluded that salad vegetables sold in Amman and Baqa’a may cause a health risk to consumers.

  10. Separation of contaminated concrete

    International Nuclear Information System (INIS)

    Bakiewicz, J.L.; Reymer, A.P.S.

    1990-01-01

    Separating the contaminated parts from the non-contaminated parts from decommissioned nuclear facilities may strongly reduce the amount of contaminated concrete. The reduction in volume of the radioactive contaminated concrete is dependent on how much cementstone is in the concrete. This research program shows that the radioactive contamination is mostly in the cementstone. However the choice that the cementstone parts, (or better said the radioactive parts) are smaller than 1 mm may not always be true. Normally the cementstone takes about 30% of the total concrete volume. A separation procedure composed by a combination of milling and thermal shock has been assessed. Both the cold and hot thermal shock in combination with milling are not able to separate the cementstone from the larger aggregates completely. However, the cementstone from the concrete with a low nominal grain size seems to be almost completely removed by the combination cold thermal shock/milling, while the cementstone from the concrete with a high nominal grain size seems to be almost completely removed by the combination hot thermal shock/milling. After both methods a layer of cementstone was still visible on the aggregates. Washing followed by a nitric acid treatment removed each 2 wt% of cementstone

  11. Costs of groundwater contamination

    International Nuclear Information System (INIS)

    O'Neil, W.B.; Raucher, R.S.

    1990-01-01

    Two factors determine the cost of groundwater contamination: (1) the ways in which water was being used or was expected to be used in the future and (2) the physical characteristics of the setting that constrain the responses available to regain lost uses or to prevent related damages to human health and the environment. Most contamination incidents can be managed at a low enough cost that uses will not be foreclosed. It is important to take into account the following when considering costs: (1) natural cleansing through recharge and dilution can take many years; (2) it is difficult and costly to identify the exact area and expected path of a contamination plume; and (3) treatment or replacement of contaminated water often may represent the cost-effective strategy for managing the event. The costs of contamination include adverse health effects, containment and remediation, treatment and replacement costs. In comparing the costs and benefits of prevention programs with those of remediation, replacement or treatment, it is essential to adjust the cost/benefit numbers by the probability of their actual occurrence. Better forecasts of water demand are needed to predict more accurately the scarcity of new supply and the associated cost of replacement. This research should include estimates of the price elasticity of water demand and the possible effect on demand of more rational cost-based pricing structures. Research and development of techniques for in situ remediation should be encouraged

  12. Preliminary study of radium-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Healy, J.W.; Rodgers, J.C.

    1978-10-01

    A preliminary study was made of the potential radiation exposures to people from radium-226 contamination in the soil in order to provide guidance on limits to be applied in decontaminating land. Pathways included were inhalation of radium from resuspension; ingestion of radium with foods; external gamma radiation from radium daughters; inhalation of radon and daughter, both in the open air and in houses; and the intake of /sup 210/Pb and /sup 210/Po from both inhalation and ingestion. The depth of the contaminated layer is of importance for external exposure and especially for radon emanation. The most limiting pathway was found to be emanation of the radon into buildings with limiting values comparable to those found naturally in many areas.

  13. Soil contamination standards for protection of personnel

    International Nuclear Information System (INIS)

    Rittmann, P.D.

    1998-01-01

    The objective of this report is to recommend soil contamination levels that will ensure that radionuclide intakes by unprotected workers are likely to give internal doses below selected dose limits during the working year. The three internal dose limits are 1, 100, and 500 mrem per year. In addition, photon, beta, and alpha instrument readings are estimated for these soil concentration limits. Two exposure pathways are considered: the first is inhalation of resuspended dust and the second is ingestion of trace amounts of soil. In addition, radioactive decay and ingrowth of progeny during the year of exposure is included. External dose from the soil contamination is not included because monitoring and control of external exposures is carried out independently from internal exposures, which are the focus of this report. The methods used are similar to those used by Carbaugh and Bihl (1993) to set bioassay criteria for such workers

  14. Preliminary study of radium-contaminated soils

    International Nuclear Information System (INIS)

    Healy, J.W.; Rodgers, J.C.

    1978-10-01

    A preliminary study was made of the potential radiation exposures to people from radium-226 contamination in the soil in order to provide guidance on limits to be applied in decontaminating land. Pathways included were inhalation of radium from resuspension; ingestion of radium with foods; external gamma radiation from radium daughters; inhalation of radon and daughter, both in the open air and in houses; and the intake of 210 Pb and 210 Po from both inhalation and ingestion. The depth of the contaminated layer is of importance for external exposure and especially for radon emanation. The most limiting pathway was found to be emanation of the radon into buildings with limiting values comparable to those found naturally in many areas

  15. Soil contamination standards for protection of personnel

    Energy Technology Data Exchange (ETDEWEB)

    Rittmann, P.D.

    1998-04-16

    The objective of this report is to recommend soil contamination levels that will ensure that radionuclide intakes by unprotected workers are likely to give internal doses below selected dose limits during the working year. The three internal dose limits are 1, 100, and 500 mrem per year. In addition, photon, beta, and alpha instrument readings are estimated for these soil concentration limits. Two exposure pathways are considered: the first is inhalation of resuspended dust and the second is ingestion of trace amounts of soil. In addition, radioactive decay and ingrowth of progeny during the year of exposure is included. External dose from the soil contamination is not included because monitoring and control of external exposures is carried out independently from internal exposures, which are the focus of this report. The methods used are similar to those used by Carbaugh and Bihl (1993) to set bioassay criteria for such workers.

  16. Implementation guide of internal contamination control

    International Nuclear Information System (INIS)

    Balter, Henia; Savio, Eduardo; Souto, Beatriz

    1994-01-01

    A review of current methods of contamination control for radioisotopes 131I, 125I and 99mTc, periodic control of personnel exposed to radiation.Maximum permissible body burden (Mpbb) for each radionuclide,radiotoxicity as danger of internal contamination directly related with Let, type of radiation,Ali values for various radionuclides and external irradiation as an opposed factor.Effective half life,examples, 99mTc in urine,iodine in thyroid caption, 99m Tc absorption by skin and mouth. Procedure of control and calculation by measurement of urine samples in a gamma spectrometer. Iodine thyroid caption by monitoring of thyroid with a solid NaI(TI)scintillator taking as background radiation the activity of upper leg muscle. Standard solutions are prepared to fill a thyroid phantoms.Results must not be higher than Mpbb of corresponding radionuclide.Bibliography

  17. Contamination Control for Thermal Engineers

    Science.gov (United States)

    Rivera, Rachel B.

    2015-01-01

    The presentation will be given at the 26th Annual Thermal Fluids Analysis Workshop (TFAWS 2015) hosted by the Goddard Spaceflight Center (GSFC) Thermal Engineering Branch (Code 545). This course will cover the basics of Contamination Control, including contamination control related failures, the effects of contamination on Flight Hardware, what contamination requirements translate to, design methodology, and implementing contamination control into Integration, Testing and Launch.

  18. Th biodistribution in internal contamination of animals

    International Nuclear Information System (INIS)

    Ciubotariu, M.; Danis, A.; Dumitrescu, G.; Cucu, M.

    1999-01-01

    Fissionable elements (U,Th) internal contamination have been studied using the fission track method as analysis method of the U and/or Th contaminant elements and Wistar-London breed rats as experiment animals. Different ways to obtain internal contaminations have been investigated: ingestion, inhalation, absorption by skin and through wounds. After the U internal contamination study was carried out, in this stage the Th internal contamination by ingestion is in progress. Using the identical aliquot parts of a solution calibrated in Th, corresponding to an Annual Limit Intake, three Wistar-London breed rats were contaminated. They were kept in normal life conditions and under permanent medical surveillance up to their sacrification. The animals were sacrificed at different time intervals after their contamination: 2 days, 7 days and 14 days, respectively. After the sacrification, their vital organs were sampled, weighed, calcined, re-weighed and finally analysed by track detection using the fission track micro-mappings technique. Also, their evacuations were sampled every 24 hours weighed, calcined and analysed in the same way as the vital organs. The Th fission track micro-mappings technique was used in the following conditions: - mica-muscovite as track detector pre-etched for fossil tracks 18 h in HF-40 per cent at room temperature; - the neutron irradiations were performed in the nuclear reactor VVR-S Bucharest at the neutron fluences of 3.10 15 - 2.10 16 fast neutrons/c m 2 ; - the visualization of the Th induced fission tracks were obtained by chemical etching in HF-40 per cent, 3 h at room temperature; - the Th track micro-mappings obtained in track detectors were studied by optical microscopy using a stereo microscope WILD M7S for ensemble study (X6-X31) and a binocular ZEISS JENA microscope for qualitative and quantitative studies (X150). The biological reference materials calibrated in Th were prepared in our laboratory using the calcined organs and the

  19. Listeria monocytogenes Growth Kinetics in Milkshakes Made from Naturally and Artificially Contaminated Ice Cream

    OpenAIRE

    Salazar, Joelle K.; Bathija, Vriddi M.; Carstens, Christina K.; Narula, Sartaj S.; Shazer, Arlette; Stewart, Diana; Tortorello, Mary Lou

    2018-01-01

    This study assessed the growth of Listeria monocytogenes in milkshakes made using the process-contaminated ice cream associated with a listeriosis outbreak in comparison to milkshakes made with artificially contaminated ice cream. For all temperatures, growth kinetics including growth rates, lag phases, maximum populations, and population increases were determined for the naturally and artificially derived contaminants at 5, 10, 15, and 25°C storage for 144 h. The artificially inoculated L. m...

  20. Bayesian Maximum Entropy space/time estimation of surface water chloride in Maryland using river distances.

    Science.gov (United States)

    Jat, Prahlad; Serre, Marc L

    2016-12-01

    Widespread contamination of surface water chloride is an emerging environmental concern. Consequently accurate and cost-effective methods are needed to estimate chloride along all river miles of potentially contaminated watersheds. Here we introduce a Bayesian Maximum Entropy (BME) space/time geostatistical estimation framework that uses river distances, and we compare it with Euclidean BME to estimate surface water chloride from 2005 to 2014 in the Gunpowder-Patapsco, Severn, and Patuxent subbasins in Maryland. River BME improves the cross-validation R 2 by 23.67% over Euclidean BME, and river BME maps are significantly different than Euclidean BME maps, indicating that it is important to use river BME maps to assess water quality impairment. The river BME maps of chloride concentration show wide contamination throughout Baltimore and Columbia-Ellicott cities, the disappearance of a clean buffer separating these two large urban areas, and the emergence of multiple localized pockets of contamination in surrounding areas. The number of impaired river miles increased by 0.55% per year in 2005-2009 and by 1.23% per year in 2011-2014, corresponding to a marked acceleration of the rate of impairment. Our results support the need for control measures and increased monitoring of unassessed river miles. Copyright © 2016. Published by Elsevier Ltd.