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Sample records for assurance sampling method

  1. Specified assurance level sampling procedure

    International Nuclear Information System (INIS)

    In the nuclear industry design specifications for certain quality characteristics require that the final product be inspected by a sampling plan which can demonstrate product conformance to stated assurance levels. The Specified Assurance Level (SAL) Sampling Procedure has been developed to permit the direct selection of attribute sampling plans which can meet commonly used assurance levels. The SAL procedure contains sampling plans which yield the minimum sample size at stated assurance levels. The SAL procedure also provides sampling plans with acceptance numbers ranging from 0 to 10, thus, making available to the user a wide choice of plans all designed to comply with a stated assurance level

  2. QUALITY ASSESSEMENT OF ANTE-NATAL CARE USING THE METHOD OF LOT QUALITY ASSURANCE SAMPLING

    Directory of Open Access Journals (Sweden)

    Sh. Salarilak

    1999-08-01

    Full Text Available To determine the coverage rate, timeliness and quality of ante-natal care in rural areas under the coverage of Health Houses in West Azerbaijan province, 30 Health Houses (HH were randomly selected out of 731 HH in the province. In each HH, using the method of Lot Quality Assurance Sampling (LQAS 28 women having recently born babies was selected. Data were collected using check-list for facilities, and questionnaires and forms to be completed from the files by interview. The study showed that the method of LQAS is quite effective for evaluation of this service at HH level. The weighted total coverage of ante-natal care was 46.2%. Quality of care was acceptable for 53.9% of mothers. The weighted average of time lines of care was 49.8%. Availability of facilities in delivery of this service was 100%, showing there was no short coming in this respect.

  3. Field trial of applicability of lot quality assurance sampling survey method for rapid assessment of prevalence of active trachoma.

    OpenAIRE

    2003-01-01

    OBJECTIVE: To test the applicability of lot quality assurance sampling (LQAS) for the rapid assessment of the prevalence of active trachoma. METHODS: Prevalence of active trachoma in six communities was found by examining all children aged 2-5 years. Trial surveys were conducted in these communities. A sampling plan appropriate for classifying communities with prevalences or =40% was applied to the survey data. Operating characteristic and average sample number curves were plo...

  4. QUALITY ASSURANCE PROCEDURES: METHOD 5G DETERMINATION OF PARTICULATE EMISSIONS FROM WOOD HEATERS FROM A DILUTION TUNNEL SAMPLING LOCATION

    Science.gov (United States)

    Quality assurance procedures are contained in this comprehensive document intended to be used as an aid for wood heater manufacturers and testing laboratories in performing particulate matter sampling of wood heaters according to EPA protocol, Method 5G. These procedures may be u...

  5. Performance of the Lot Quality Assurance Sampling Method Compared to Surveillance for Identifying Inadequately-performing Areas in Matlab, Bangladesh

    OpenAIRE

    Bhuiya, Abbas; Hanifi, S M A; Roy, Nikhil; Streatfield, P. Kim

    2007-01-01

    This paper compared the performance of the lot quality assurance sampling (LQAS) method in identifying inadequately-performing health work-areas with that of using health and demographic surveillance system (HDSS) data and examined the feasibility of applying the method by field-level programme supervisors. The study was carried out in Matlab, the field site of ICDDR,B, where a HDSS has been in place for over 30 years. The LQAS method was applied in 57 work-areas of community health workers i...

  6. Radioactivity in environmental samples: calibration standards measurement methods, quality assurance, and data analysis

    International Nuclear Information System (INIS)

    The numerous environmental radioactivity measurements made by and for the U.S. Environmental Protection Agency (U.S.EPA) include measurements on samples of water, urine, food, milk, and air filters. Calibration standards are listed which are available in the form of water solutions and soils for a wide range of radionuclides. Method validation procedures for U.S. EPA approval include protocol development and single-laboratory and multiple-laboratory evaluation for precision and accuracy. Inter-laboratory comparison studies are conducted for both cross-check and performance evaluation samples and involve 295 federal, state, and local laboratories. For water samples, 80% to 90% of the participating laboratories are within the control limits for most of the radionuclides measured; however, some problem areas exist, especially for radium-228 and strontium-89 and -90. For milk and food samples, more than 90% of the laboratories are within control limits for cobalt-60 and cesium-137 but some problems exist for the measurement of strontium-90, iodine-131, and potassium-40. For tritium, 91% of the laboratories are within the control limit for water samples and 87% are within the control limits for the urine samples. The laboratory performance for air filter samples shows some problems for gross beta, strontium-90 and cesium-137 measurements. (author)

  7. Prevalence study of yaws in the Democratic Republic of Congo using the lot quality assurance sampling method.

    Directory of Open Access Journals (Sweden)

    Sibylle Gerstl

    Full Text Available BACKGROUND: Until the 1970s the prevalence of non-venereal trepanomatosis, including yaws, was greatly reduced after worldwide mass treatment. In 2005, cases were again reported in the Democratic Republic of the Congo. We carried out a survey to estimate the village-level prevalence of yaws in the region of Equator in the north of the country in order to define appropriate strategies to effectively treat the affected population. METHODOLOGY/PRINCIPAL FINDINGS: We designed a community-based survey using the Lot Quality Assurance Sampling method to classify the prevalence of active yaws in 14 groups of villages (lots. The classification into high, moderate, or low yaws prevalence corresponded to World Health Organization prevalence thresholds for identifying appropriate operational treatment strategies. Active yaws cases were defined by suggestive clinical signs and positive rapid plasma reagin and Treponema pallidum hemagglutination serological tests. The overall prevalence in the study area was 4.7% (95% confidence interval: 3.4-6.0. Two of 14 lots had high prevalence (>10%, three moderate prevalence (5-10% and nine low prevalence (<5%.. CONCLUSIONS/SIGNIFICANCE: Although yaws is no longer a World Health Organization priority disease, the presence of yaws in a region where it was supposed to be eradicated demonstrates the importance of continued surveillance and control efforts. Yaws should remain a public health priority in countries where previously it was known to be endemic. The integration of sensitive surveillance systems together with free access to effective treatment is recommended. As a consequence of our study results, more than 16,000 people received free treatment against yaws.

  8. Comparative validation study to demonstrate the equivalence of a minor modification to AOAC official method 2005.04 assurance GdS E. coli 0157:H7 method to the reference culture method: 375 gram sample size.

    Science.gov (United States)

    Feldsine, Philip T; Montgomery-Fullerton, Megan; Roa, Nerie; Kaur, Mandeep; Lienau, Andrew H; Jucker, Markus; Kerr, David E

    2013-01-01

    The Assurance GDS Escherichia coli (E. col) O157:H7, AOAC Official Method 2005.04, has been modified to include a larger sample size of 375 g. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture method. Ninety samples and controls, representing three foods, were analyzed. Results show no statistically detectable difference between the Assurance GDS E. coli O157:H7 assay and the reference culture methods for the detection of E. coli O157:H7, other than the low level of inoculation for leaf lettuce, for which the GDS gave noticeably higher recovery [difference in probability of detection between candidate methods (dPODc = +0.45)]. There were also suggestions of moderate differences (dPODc = +0.15 to +0.20) for ground beef and the high level of leaf lettuce, but the study size was too small to detect differences of this size. Results showed that the Assurance GDS E. coli O157:H7 method is equivalent to reference culture methods for the detection of E. coli O157:H7. PMID:24000751

  9. Comparative validation study to demonstrate the equivalence of a minor modification to AOAC Official Method 2005.05 Assurance GDS shiga Toxin Genes (O157) method to the reference culture method: 375 gram sample size.

    Science.gov (United States)

    Feldsine, Philip T; Montgomery-Fullerton, Megan; Roa, Nerie; Kaur, Mandeep; Kerr, David E; Lienau, Andrew H; Jucker, Markus

    2013-01-01

    The Assurance GDS Shiga Toxin Genes (0157), AOAC Official MethodsM 2005.05, has been modified to include a larger sample size of 375 g. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture method. Ninety samples and controls, representing three foods, were analyzed. Results show no statistically detectable difference between the Assurance GDS Escherichia coli O157:H7 assay and the reference culture methods for the detection of E. coli O157:H7, other than the low level of inoculation for leaf lettuce for which the GDS gave noticeably higher recovery [difference in Probability of Detection between candidate methods (dPODc = +0.45)]. There were also suggestions of moderate differences (dPODc = +0.15 to +0.20) for ground beef and the high level of leaf lettuce, but the study size was too small to detect differences of this size. Results showed that the Assurance GDS Shiga Toxin Genes (0157) method is equivalent to the reference culture methods for the detection of Shiga toxigenic E. coli O157:H7. PMID:24000752

  10. Sampling methods

    OpenAIRE

    Kılıç, Selim

    2013-01-01

    Most of the studies related to health are conducted with samples. Selection of sampling may be performed with random or nonrandom sampling methods. Sampling methods may vary with respect to some characteristics of study population, researchers’ aims and facilities. It is necessary to select samples by random sampling methods in order to provide the representativeness of the study population. The advantages and disadvantages of different sampling methods are presented in this manuscript which ...

  11. Statistical methods for quality assurance

    International Nuclear Information System (INIS)

    This is the first German-language textbook on quality assurance and the fundamental statistical methods that is suitable for private study. The material for this book has been developed from a course of Hagen Open University and is characterized by a particularly careful didactical design which is achieved and supported by numerous illustrations and photographs, more than 100 exercises with complete problem solutions, many fully displayed calculation examples, surveys fostering a comprehensive approach, bibliography with comments. The textbook has an eye to practice and applications, and great care has been taken by the authors to avoid abstraction wherever appropriate, to explain the proper conditions of application of the testing methods described, and to give guidance for suitable interpretation of results. The testing methods explained also include latest developments and research results in order to foster their adoption in practice. (orig.)

  12. Statistical methods in quality assurance

    International Nuclear Information System (INIS)

    During the different phases of a production process - planning, development and design, manufacturing, assembling, etc. - most of the decision rests on a base of statistics, the collection, analysis and interpretation of data. Statistical methods can be thought of as a kit of tools to help to solve problems in the quality functions of the quality loop with respect to produce quality products and to reduce quality costs. Various statistical methods are represented, typical examples for their practical application are demonstrated. (RW)

  13. Authentication Assurance Level Application to the Inventory Sampling Measurement System

    Energy Technology Data Exchange (ETDEWEB)

    Devaney, Mike M.; Kouzes, Richard T.; Hansen, Randy R.; Geelhood, Bruce D.

    2001-09-06

    This document concentrates on the identification of a standardized assessment approach for the verification of security functionality in specific equipment, the Inspection Sampling Measurement System (ISMS) being developed for MAYAK. Specifically, an Authentication Assurance Level 3 is proposed to be reached in authenticating the ISMS.

  14. Authentication Assurance Level Application to the Inventory Sampling Measurement System

    International Nuclear Information System (INIS)

    This document concentrates on the identification of a standardized assessment approach for the verification of security functionality in specific equipment, the Inspection Sampling Measurement System (ISMS) being developed for MAYAK. Specifically, an Authentication Assurance Level 3 is proposed to be reached in authenticating the ISMS

  15. Sampling quality assurance guidance in support of EM environmental sampling and analysis activities

    Energy Technology Data Exchange (ETDEWEB)

    1994-05-01

    This document introduces quality assurance guidance pertaining to the design and implementation of sampling procedures and processes for collecting environmental data for DOE`s Office of EM (Environmental Restoration and Waste Management).

  16. Sampling quality assurance guidance in support of EM environmental sampling and analysis activities

    International Nuclear Information System (INIS)

    This document introduces quality assurance guidance pertaining to the design and implementation of sampling procedures and processes for collecting environmental data for DOE's Office of EM (Environmental Restoration and Waste Management)

  17. The effect of clustering on lot quality assurance sampling: a probabilistic model to calculate sample sizes for quality assessments

    OpenAIRE

    Hedt-Gauthier, Bethany L; Mitsunaga, Tisha; Hund, Lauren; Olives, Casey; Pagano, Marcello

    2013-01-01

    Background: Traditional Lot Quality Assurance Sampling (LQAS) designs assume observations are collected using simple random sampling. Alternatively, randomly sampling clusters of observations and then individuals within clusters reduces costs but decreases the precision of the classifications. In this paper, we develop a general framework for designing the cluster(C)-LQAS system and illustrate the method with the design of data quality assessments for the community health worker program in Rw...

  18. Quality assurance strategies in hospitals: Development, implementation and impact of quality assurance methods in Iranian hospitals

    NARCIS (Netherlands)

    A. Aghaei Hashjin

    2015-01-01

    This thesis concentrates on the subject of quality assurance strategies in hospitals; exploring the development, implementation and impact of quality assurance (QA) methods in Iranian hospitals. A series of descriptive and analytical studies using qualitative and quantitative data were performed. Th

  19. Extending cluster lot quality assurance sampling designs for surveillance programs.

    Science.gov (United States)

    Hund, Lauren; Pagano, Marcello

    2014-07-20

    Lot quality assurance sampling (LQAS) has a long history of applications in industrial quality control. LQAS is frequently used for rapid surveillance in global health settings, with areas classified as poor or acceptable performance on the basis of the binary classification of an indicator. Historically, LQAS surveys have relied on simple random samples from the population; however, implementing two-stage cluster designs for surveillance sampling is often more cost-effective than simple random sampling. By applying survey sampling results to the binary classification procedure, we develop a simple and flexible nonparametric procedure to incorporate clustering effects into the LQAS sample design to appropriately inflate the sample size, accommodating finite numbers of clusters in the population when relevant. We use this framework to then discuss principled selection of survey design parameters in longitudinal surveillance programs. We apply this framework to design surveys to detect rises in malnutrition prevalence in nutrition surveillance programs in Kenya and South Sudan, accounting for clustering within villages. By combining historical information with data from previous surveys, we design surveys to detect spikes in the childhood malnutrition rate. PMID:24633656

  20. Iodine-129: Sample preparation, quality assurance and analysis of environmental samples

    International Nuclear Information System (INIS)

    The long-lived radionuclide 129I (half-live 15.7 Ma) occurs in the environment due to spontaneous fission of uranium in the earth-crust and in oceans, and due to cosmic-ray induced spallation of xenon in the stratosphere. Military and civilian use of induced nuclear fission by man increased natural abundances by two to seven orders of magnitude during the last sixty years. Among that, substantial emissions originate from reprocessing of spent nuclear fuel. Three main goals are pursued by examining 129I in environmental materials: The observation of dimensions and radiological relevances of anthropogenic emissions during the last decades, the use of 129I as a tracer of environmental processes, and the determination of natural, pre-nuclear 129I/127I ratios. For that, precipitation, surface, and ground waters from Lower Saxony, Germany, were systematically investigated from 1997 to 1999, extended by single seawater samples. In addition, a reconstruction of past 129I concentrations and 129I/127I ratios was attempted with archived soil and thyroid samples. Accelerator mass spectrometry (AMS) was used in this study. Besides the measurements of environmental samples, emphasis was laid upon the refinement of these analytical and chemical procedures: New sample preparation methods, quality assurance, the possibility of a carrier-free sample preparation and measurement with AMS, and a detailed statistical evaluation of raw data

  1. A method of safety assurance for fusion experimental reactor

    International Nuclear Information System (INIS)

    The present report describes safety assurance method for fusion experimental reactor. The ALARA (As Low As Reasonably Achievable) principle for a normal condition and the defence in depth principle for states deviated from the normal condition can be used as basic principles of safety assurance of the reactor. The method includes safety design for systems, importance categorization method to impose suitable demands to their systems, safety evaluation method to validate the design and application of the method. It is considered that this method can be a strong candidate for safety assurance method. (author)

  2. Analysis of large samples by neutron activation analysis. Quality assurance aspects

    International Nuclear Information System (INIS)

    The need for quality assurance in large sample instrumental neutron activation analysis (INAA) requires the development of unconventional methods of quality control. Certified reference materials are not available at the 1-5 kg scale; moreover, inhomogeneities which might affect the accuracy of the real sample analysis would not be reflected in the analysis of a reference material or in-house control sample even when available. Model studies indicate that inhomogeneities with strong gamma ray absorbing properties have the largest effect on the accuracy of the concentrations. The occurrence of these inhomogeneities may be derived from gamma spectrum analysis. Other opportunities for quality assurance are with the calculated estimates of the parameters describing neutron and gamma ray self-attenuation, and eventually through direct assessment after homogenization of the large sample, subsampling and conventional analysis. (author)

  3. Measurement assurance program for FTIR analyses of deuterium oxide samples

    International Nuclear Information System (INIS)

    Analytical chemistry measurements require an installed criterion based assessment program to identify and control sources of error. This program should also gauge the uncertainty about the data. A self- assessment was performed of long established quality control practices against the characteristics of a comprehensive measurement assurance program. Opportunities for improvement were identified. This paper discusses the efforts to transform quality control practices into a complete measurement assurance program. The resulting program heightened the laboratory's confidence in the data it generated, by providing real-time statistical information to control and determine measurement quality

  4. QUALITY ASSURANCE PROCEDURES: METHOD 28 CERTIFICATION AND AUDITING OF WOOD HEATERS

    Science.gov (United States)

    Quality assurance procedures are contained in this comprehensive document intended to be used as an aid for wood heater manufacturers and testing laboratories in performing particulate matter sampling of wood heaters according to EPA protocol, Method 28. These procedures may be u...

  5. Procedures for sampling and sample reduction within quality assurance systems for solid biofuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The objective of this experimental study on sampling was to determine the size and number of samples of biofuels required (taken at two sampling points in each case) and to compare two methods of sampling. The first objective of the sample-reduction exercise was to compare the reliability of various sampling methods, and the second objective was to measure the variations introduced as a result of reducing the sample size to form suitable test portions. The materials studied were sawdust, wood chips, wood pellets and bales of straw, and these were analysed for moisture, ash, particle size and chloride. The sampling procedures are described. The study was conducted in Scandinavia. The results of the study were presented in Leipzig in October 2004. The work was carried out as part of the UK's DTI Technology Programme: New and Renewable Energy.

  6. Radioactive air sampling methods

    CERN Document Server

    Maiello, Mark L

    2010-01-01

    Although the field of radioactive air sampling has matured and evolved over decades, it has lacked a single resource that assimilates technical and background information on its many facets. Edited by experts and with contributions from top practitioners and researchers, Radioactive Air Sampling Methods provides authoritative guidance on measuring airborne radioactivity from industrial, research, and nuclear power operations, as well as naturally occuring radioactivity in the environment. Designed for industrial hygienists, air quality experts, and heath physicists, the book delves into the applied research advancing and transforming practice with improvements to measurement equipment, human dose modeling of inhaled radioactivity, and radiation safety regulations. To present a wide picture of the field, it covers the international and national standards that guide the quality of air sampling measurements and equipment. It discusses emergency response issues, including radioactive fallout and the assets used ...

  7. Sampling system and method

    Energy Technology Data Exchange (ETDEWEB)

    Decker, David L; Lyles, Brad F; Purcell, Richard G; Hershey, Ronald Lee

    2014-05-20

    An apparatus and method for supporting a tubing bundle during installation or removal. The apparatus includes a clamp for securing the tubing bundle to an external wireline. The method includes deploying the tubing bundle and wireline together, The tubing bundle is periodically secured to the wireline using a clamp.

  8. A method of language sampling

    DEFF Research Database (Denmark)

    Rijkhoff, Jan; Bakker, Dik; Hengeveld, Kees;

    1993-01-01

    In recent years more attention is paid to the quality of language samples in typological work. Without an adequate sampling strategy, samples may suffer from various kinds of bias. In this article we propose a sampling method in which the genetic criterion is taken as the most important: samples ...

  9. APPLICATION OF LOT QUALITY ASSURANCE SAMPLING FOR ASSESSING DISEASE CONTROL PROGRAMMES - EXAMINATION OF SOME METHODOLOGICAL ISSUES

    OpenAIRE

    T. R. RAMESH RAO

    2011-01-01

    Lot Quality Assurance Sampling (LQAS), a statistical tool in industrial setup, has been in use since 1980 for monitoring and evaluation of programs on disease control / immunization status among children / health workers performance in health system. While conducting LQAS in the field, there are occasions, even after due care of design, there are practical and methodological issues to be addressed before it is recommended for implementation and intervention. LQAS is applied under the assumpti...

  10. Quality assurance methods in the German dose rate measurement network

    International Nuclear Information System (INIS)

    The result of the gamma dose rate measurements in the context of the surveillance of environmental radioactivity depends strongly on the physical properties of the counting probes, but also on meteorological effects and the characteristics of the site in the vicinity of the dose rate probes. In the German gamma dose rate measurement network (ODL-monitoring net) substantial quality assurance efforts have been undertaken to ensure that the measured data are representative. These are, in particular, measures to determine the specific physical properties of the deployed monitors (background count rate, dependence on the cosmic radiation), an individual on-site test of the detector efficiency in the context of so-called ''method of repetitive tests'', methods for on-line correlation of precipitation and dose rate display and description of the monitor environment in context of the background capability as well as the validity in case of a contamination situation. Respective investigations have been performed in recent years and, based on the substantial amount of data, an optimisation of the practicability of the measurement data for decision support systems derived. (orig.)

  11. Quality assurance of reactor operation by computer methods

    International Nuclear Information System (INIS)

    The necessity and value of computer auditing has been proven at N Reactor. During a recent audit, discrepancies were noted when temperature calculations did not agree within +- 10F upon comparison of Quality Assurance and Reactor Operations calculations. Input data was checked and no discrepancies noted. Quality Assurance and Reactor Operations programs were executed again, using new data, and all calculations agreed within the required accuracy. A subsequent diagnostics test was performed on the Quality Assurance computer system, revealing hard (gross) computer memory failures, although further routine computer operation did not reveal this. The incident demonstrates that errors in operating limits could occur, undetected, if reliability were based solely on limits calculated by the Reactor Operations computer, without verification by means of the Quality Assurance computer. This type of incident is similarly possible at Commercial nuclear facilities which rely on one computer system only, without verification (auditing) of input parameters, subsequent calculation of operating parameters (limits), and computer operation

  12. 利用LQAS方法开展疫苗接种率调查的分析%Analysis of carrying out the immunization coverage rate survey using Lot-Quality Assurance Sampling (LQAS) method

    Institute of Scientific and Technical Information of China (English)

    谢群; 池益强; 马姗姗

    2014-01-01

    Objective To evaluate the advantage and disadvantage of LQAS in investigating immunization coverage rate in children of Xiamen city, by comparing immunization coverage rate in children of Xiamen city with routine report immunization coverage rate. Methods Forty-two eligible children were sampled from each of the three towns, Xike, Gulangyu and Jinshan with LQAS, immunization coverage rate was calculated and was compared with routine report immunization coverage rate from na-tional routine immunization system. Results The investigated immunization coverage rates of the three towns were all above 97. 62%, while the routine report immunization coverage rates were above 97. 84%. The compared results showed that there was no significant difference between the two rates in Gulangyu and Jinshan town, while the investigated immunization coverage rate in Xike town was slightly lower than that of the reported. Conclusion LQAS can be used to investigate large-scale immunization coverage rate survey and evaluate the quality of reported immunization coverage rate because it is fast and convenient. It can’t be used to estimate the level of immunization coverage rate and should be used with caution in solving practical problems. Be sure to sample randomly and control the quality of investigation when using it.%目的:比较厦门市儿童调查疫苗接种率与常规免疫报告接种率的差异,评价调查抽样方法LQAS的优点与缺点。方法采用批质量保证抽样方法( LQAS)抽取厦门3个乡镇适龄儿童各42名,调查统计儿童疫苗接种情况,并将调查疫苗接种率与中国国家常规免疫监测系统中报告疫苗接种率进行比较。结果3个街道/乡镇调查疫苗接种率均在97.62%以上,报告疫苗接种率均在97.84%以上。思明区鼓浪屿街道与湖里区金山街道调查疫苗接种率与报告疫苗接种率相比无显著性差异,而同安区西柯镇调查疫苗接种率低于报

  13. Task Technical and Quality Assurance Plan for the Characterization of Tank 25F Saltcake Core Samples

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) recognizes the need for the characterization of High-Level Waste (HLW) saltcake in the Savannah River Site (SRS) F- and H-area tank farms to support upcoming salt processing activities. As part of the enhanced characterization efforts, Tank 25F will be sampled and the samples analyzed at the Savannah River National Laboratory (SRNL). This Task Technical and Quality Assurance Plan documents the planned activities for the physical, chemical, and radiological analysis of the Tank 25F saltcake core samples. This plan does not cover other characterization activities that do not involve core sample analysis and it does not address issues regarding sampling or sample transportation. The objectives of this report are: (1) Provide information useful in projecting the composition of dissolved salt batches by quantifying important components (such as actinides, 137Cs, and 90Sr) on a per batch basis. This will assist in process selection for the treatment of salt batches and provide data for the validation of dissolution modeling. (2) Determine the properties of the heel resulting from dissolution of the bulk saltcake. Also note tendencies toward post-mixing precipitation. (3) Provide a basis for determining the number of samples needed for the characterization of future saltcake tanks. Gather information useful towards performing characterization in a manner that is more cost and time effective

  14. HDR quality assurance methods for personal digital assistants

    International Nuclear Information System (INIS)

    An important component of every clinical high-dose-rate (HDR) brachytherapy program is quality assurance (QA). One of the QA recommendations of the AAPM TG59 report is an independent verification on the results of treatment planning. It is desirable for the verification procedure to be as quick and easy to perform as possible and yet to have a high probability of detecting significant errors. The objective of this work is to describe the dosimetric methods and software developed to implement a departmental HDR QA program using personal digital assistants (PDAs). Verification of MammoSite treatment plans is presented as a practical example. PDAs that run the PalmOS were selected for their low cost and popularity among health care professionals. General-purpose applications were developed for linear sources, planar, and volume implants, that estimate the total dwell time of an HDR implant. This value can then be compared to the total dwell time calculated by the primary treatment planning system. The software incorporates the Paterson-Parker (PP) radium tables and the Greenfield-Tichman-Norman (GTN) version of the Quimby radium tables, which have been modified to a form more convenient for HDR calculations. A special purpose application based on the AAPM TG43 formalism was developed for the MammoSite breast applicator. For QA calculations perpendicular to the center of a single Iridium-192 (192I) HDR source, as exemplified by MammoSite treatments, linearly interpolating the PP or GTN tables is equivalent to applying the TG43 formalism at distances up to 5 cm from the source axis. The MammoSite-specific software also offers the option to calculate dosimetry based on the balloon volume. The PDA clock/calendar permits the software to automatically account for source decay. The touch-sensitive screen allows the familiar tabular format to be maintained while minimizing the effort required for calculations. The PP and GTN radium implant tables are easily modified to a form

  15. Quality assurance and reference material requirements and considerations for environmental sample analysis in nuclear forensics

    International Nuclear Information System (INIS)

    Full text: High-sensitivity nuclear environmental sampling and analysis techniques have been proven in their ability to verify declared nuclear activities, as well as to assist in the detection of undeclared nuclear activities and facilities. Following the Gulf War, the capability and revealing power of environmental sampling and analysis techniques to support international safeguards was demonstrated and subsequently adopted by the International Atomic Energy Agency (IAEA) as routine safeguards measures in safeguards inspections and verifications. In addition to having been proved useful in international safeguards, environmental sampling and analysis techniques have demonstrated their utility in identifying the origins of 'orphaned' nuclear material, as well as the origin of intercepted smuggled nuclear material. Today, environmental sampling and analysis techniques are now being applied in six broad areas to support nonproliferation, disarmament treaty verification, national and international nuclear security, and environmental stewardship of weapons production activities. Consequently, more and more laboratories around the world are establishing capabilities or expanding capabilities to meet these growing applications, and as such requirements for quality assurance and control are increasing. The six areas are: 1) Nuclear safeguards; 2) Nuclear forensics/illicit trafficking; 3) Ongoing monitoring and verification (OMV); 4) Comprehensive Test Ban Treaty (CTBT); 5) Weapons dismantlement/materials disposition; and 6) Research and development (R and D)/environmental stewardship/safety. Application of environmental sampling and analysis techniques and resources to illicit nuclear material trafficking, while embodying the same basic techniques and resources, does have unique requirements for sample management, handling, protocols, chain of custody, archiving, and data interpretation. These requirements are derived from needs of how data from nuclear forensics

  16. SWOT ANALYSIS ON SAMPLING METHOD

    Directory of Open Access Journals (Sweden)

    CHIS ANCA OANA

    2014-07-01

    Full Text Available Audit sampling involves the application of audit procedures to less than 100% of items within an account balance or class of transactions. Our article aims to study audit sampling in audit of financial statements. As an audit technique largely used, in both its statistical and nonstatistical form, the method is very important for auditors. It should be applied correctly for a fair view of financial statements, to satisfy the needs of all financial users. In order to be applied correctly the method must be understood by all its users and mainly by auditors. Otherwise the risk of not applying it correctly would cause loose of reputation and discredit, litigations and even prison. Since there is not a unitary practice and methodology for applying the technique, the risk of incorrectly applying it is pretty high. The SWOT analysis is a technique used that shows the advantages, disadvantages, threats and opportunities. We applied SWOT analysis in studying the sampling method, from the perspective of three players: the audit company, the audited entity and users of financial statements. The study shows that by applying the sampling method the audit company and the audited entity both save time, effort and money. The disadvantages of the method are difficulty in applying and understanding its insight. Being largely used as an audit method and being a factor of a correct audit opinion, the sampling method’s advantages, disadvantages, threats and opportunities must be understood by auditors.

  17. Multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control.

    Directory of Open Access Journals (Sweden)

    Casey Olives

    Full Text Available BACKGROUND: Originally a binary classifier, Lot Quality Assurance Sampling (LQAS has proven to be a useful tool for classification of the prevalence of Schistosoma mansoni into multiple categories (≤10%, >10 and <50%, ≥50%, and semi-curtailed sampling has been shown to effectively reduce the number of observations needed to reach a decision. To date the statistical underpinnings for Multiple Category-LQAS (MC-LQAS have not received full treatment. We explore the analytical properties of MC-LQAS, and validate its use for the classification of S. mansoni prevalence in multiple settings in East Africa. METHODOLOGY: We outline MC-LQAS design principles and formulae for operating characteristic curves. In addition, we derive the average sample number for MC-LQAS when utilizing semi-curtailed sampling and introduce curtailed sampling in this setting. We also assess the performance of MC-LQAS designs with maximum sample sizes of n=15 and n=25 via a weighted kappa-statistic using S. mansoni data collected in 388 schools from four studies in East Africa. PRINCIPLE FINDINGS: Overall performance of MC-LQAS classification was high (kappa-statistic of 0.87. In three of the studies, the kappa-statistic for a design with n=15 was greater than 0.75. In the fourth study, where these designs performed poorly (kappa-statistic less than 0.50, the majority of observations fell in regions where potential error is known to be high. Employment of semi-curtailed and curtailed sampling further reduced the sample size by as many as 0.5 and 3.5 observations per school, respectively, without increasing classification error. CONCLUSION/SIGNIFICANCE: This work provides the needed analytics to understand the properties of MC-LQAS for assessing the prevalance of S. mansoni and shows that in most settings a sample size of 15 children provides a reliable classification of schools.

  18. Distance sampling methods and applications

    CERN Document Server

    Buckland, S T; Marques, T A; Oedekoven, C S

    2015-01-01

    In this book, the authors cover the basic methods and advances within distance sampling that are most valuable to practitioners and in ecology more broadly. This is the fourth book dedicated to distance sampling. In the decade since the last book published, there have been a number of new developments. The intervening years have also shown which advances are of most use. This self-contained book covers topics from the previous publications, while also including recent developments in method, software and application. Distance sampling refers to a suite of methods, including line and point transect sampling, in which animal density or abundance is estimated from a sample of distances to detected individuals. The book illustrates these methods through case studies; data sets and computer code are supplied to readers through the book’s accompanying website.  Some of the case studies use the software Distance, while others use R code. The book is in three parts.  The first part addresses basic methods, the ...

  19. Transuranic waste characterization sampling and analysis methods manual

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    The Transuranic Waste Characterization Sampling and Analysis Methods Manual (Methods Manual) provides a unified source of information on the sampling and analytical techniques that enable Department of Energy (DOE) facilities to comply with the requirements established in the current revision of the Transuranic Waste Characterization Quality Assurance Program Plan (QAPP) for the Waste Isolation Pilot Plant (WIPP) Transuranic (TRU) Waste Characterization Program (the Program). This Methods Manual includes all of the testing, sampling, and analytical methodologies accepted by DOE for use in implementing the Program requirements specified in the QAPP.

  20. Transuranic waste characterization sampling and analysis methods manual

    International Nuclear Information System (INIS)

    The Transuranic Waste Characterization Sampling and Analysis Methods Manual (Methods Manual) provides a unified source of information on the sampling and analytical techniques that enable Department of Energy (DOE) facilities to comply with the requirements established in the current revision of the Transuranic Waste Characterization Quality Assurance Program Plan (QAPP) for the Waste Isolation Pilot Plant (WIPP) Transuranic (TRU) Waste Characterization Program (the Program). This Methods Manual includes all of the testing, sampling, and analytical methodologies accepted by DOE for use in implementing the Program requirements specified in the QAPP

  1. Sediment laboratory quality-assurance project: studies of methods and materials

    Science.gov (United States)

    Gordon, J.D.; Newland, C.A.; Gray, J.R.

    2001-01-01

    In August 1996 the U.S. Geological Survey initiated the Sediment Laboratory Quality-Assurance project. The Sediment Laboratory Quality Assurance project is part of the National Sediment Laboratory Quality-Assurance program. This paper addresses the fmdings of the sand/fme separation analysis completed for the single-blind reference sediment-sample project and differences in reported results between two different analytical procedures. From the results it is evident that an incomplete separation of fme- and sand-size material commonly occurs resulting in the classification of some of the fme-size material as sand-size material. Electron microscopy analysis supported the hypothesis that the negative bias for fme-size material and the positive bias for sand-size material is largely due to aggregation of some of the fine-size material into sand-size particles and adherence of fine-size material to the sand-size grains. Electron microscopy analysis showed that preserved river water, which was low in dissolved solids, specific conductance, and neutral pH, showed less aggregation and adhesion than preserved river water that was higher in dissolved solids and specific conductance with a basic pH. Bacteria were also found growing in the matrix, which may enhance fme-size material aggregation through their adhesive properties. Differences between sediment-analysis methods were also investigated as pan of this study. Suspended-sediment concentration results obtained from one participating laboratory that used a total-suspended solids (TSS) method had greater variability and larger negative biases than results obtained when this laboratory used a suspended-sediment concentration method. When TSS methods were used to analyze the reference samples, the median suspended sediment concentration percent difference was -18.04 percent. When the laboratory used a suspended-sediment concentration method, the median suspended-sediment concentration percent difference was -2

  2. The Multivariate Ahrens Sampling Method

    OpenAIRE

    Karawatzki, Roman

    2006-01-01

    The "Ahrens method" is a very simple method for sampling from univariate distributions. It is based on rejection from piecewise constant hat functions. It can be applied analogously to the multivariate case where hat functions are used that are constant on rectangular domains. In this paper we investigate the case of distributions with so called orthounimodal densities. Technical implementation details as well as their practical limitations are discussed. The application to more general distr...

  3. Development of quality assurance methods for low enriched fuel assemblies

    International Nuclear Information System (INIS)

    As the Reduced Enrichment for Research and Test Reactors (RERTR) fuel development program has furthered the technology of low enriched uranium fuels, much effort has been expended to specify requirements, perform appropriate inspections, and to qualify experimental fuel plates and assemblies for irradiation. A great deal of consideration has been given to generate examinations and criteria that are both applicable to the unique fuel types being developed and consistent with industry practices for inspecting plate-type reactor fuel. Recent developments in quality assurance (QA) methodologies have given a heightened confidence in satisfactory fuel plate performance. At the same time, recommendations are given to further develop a system suitable for the testing and acceptance of production fuel elements containing low enriched uranium fuels. (author)

  4. Use of Lot Quality Assurance Sampling to Ascertain Levels of Drug Resistant Tuberculosis in Western Kenya.

    Directory of Open Access Journals (Sweden)

    Julia Jezmir

    Full Text Available To classify the prevalence of multi-drug resistant tuberculosis (MDR-TB in two different geographic settings in western Kenya using the Lot Quality Assurance Sampling (LQAS methodology.The prevalence of drug resistance was classified among treatment-naïve smear positive TB patients in two settings, one rural and one urban. These regions were classified as having high or low prevalence of MDR-TB according to a static, two-way LQAS sampling plan selected to classify high resistance regions at greater than 5% resistance and low resistance regions at less than 1% resistance.This study classified both the urban and rural settings as having low levels of TB drug resistance. Out of the 105 patients screened in each setting, two patients were diagnosed with MDR-TB in the urban setting and one patient was diagnosed with MDR-TB in the rural setting. An additional 27 patients were diagnosed with a variety of mono- and poly- resistant strains.Further drug resistance surveillance using LQAS may help identify the levels and geographical distribution of drug resistance in Kenya and may have applications in other countries in the African Region facing similar resource constraints.

  5. Use of Lot Quality Assurance Sampling to Ascertain Levels of Drug Resistant Tuberculosis in Western Kenya

    Science.gov (United States)

    Cohen, Ted; Zignol, Matteo; Nyakan, Edwin; Hedt-Gauthier, Bethany L.; Gardner, Adrian; Kamle, Lydia; Injera, Wilfred; Carter, E. Jane

    2016-01-01

    Objective To classify the prevalence of multi-drug resistant tuberculosis (MDR-TB) in two different geographic settings in western Kenya using the Lot Quality Assurance Sampling (LQAS) methodology. Design The prevalence of drug resistance was classified among treatment-naïve smear positive TB patients in two settings, one rural and one urban. These regions were classified as having high or low prevalence of MDR-TB according to a static, two-way LQAS sampling plan selected to classify high resistance regions at greater than 5% resistance and low resistance regions at less than 1% resistance. Results This study classified both the urban and rural settings as having low levels of TB drug resistance. Out of the 105 patients screened in each setting, two patients were diagnosed with MDR-TB in the urban setting and one patient was diagnosed with MDR-TB in the rural setting. An additional 27 patients were diagnosed with a variety of mono- and poly- resistant strains. Conclusion Further drug resistance surveillance using LQAS may help identify the levels and geographical distribution of drug resistance in Kenya and may have applications in other countries in the African Region facing similar resource constraints. PMID:27167381

  6. International symposium on quality assurance for analytical methods in isotope hydrology. Book of extended synopses

    International Nuclear Information System (INIS)

    A large variety of isotopic techniques is available and commonly used in water resources investigations as well as in a wide range of other scientific fields. These techniques include the stable isotope analysis of light elements (H, C, N, O, S), activity measurements of radioactive isotopes at environmental level (3H, 14C, 3H/3He, 85Kr) as well as measurements of CFCs, SF6 and other chemical and isotopic tracers. They provide valuable tools for the assessment of scientific questions and the solution of practical problems. During the last decade, new analytical tools have significantly fostered the application of isotopic techniques in many new fields and caused a steep increase in the number of laboratories applying these methods. International trends in improved analytical quality and requirements for laboratory certification and accreditation have pushed issues of quality control and quality assurance to a high level of importance for the operation of isotope laboratories worldwide. The objectives of the symposium are to promote a wide exchange of information on key issues for high quality isotopic measurements. The main focus is on the analytical techniques and on all means to ensure high quality standards for isotopic measurements. Recent advances in analytical quality assurance and laboratory quality systems will be presented and discussed together with state-of-the-art techniques. The scope of the conference is to demonstrate the use of best laboratory practices in the following fields: calibration of measurements and traceability; interlaboratory comparisons; best laboratory practices for daily analyses of samples; quality control and statistical evaluation of results; calculation of uncertainty budgets; new analytical techniques; improvements in precision and accuracy of analytical methods; laboratory information management, databases and sample handling; laboratory quality systems and international guides. The 42 papers are indexed individually

  7. Tracking the Quality of Care for Sick Children Using Lot Quality Assurance Sampling: Targeting Improvements of Health Services in Jigawa, Nigeria

    OpenAIRE

    Oladele, Edward Adekola; Ormond, Louise; Adeyemi, Olusegun; Patrick, David; Okoh, Festus; Oresanya, Olusola Bukola; Valadez, Joseph J

    2012-01-01

    Background In Nigeria, 30% of child deaths are due to malaria. The National Malaria Control Program of Nigeria (NMCP) during 2009 initiated a program to improve the quality of paediatric malaria services delivered in health facilities (HF). This study reports a rapid approach used to assess the existing quality of services in Jigawa state at decentralised levels of the health system. Methods NMCP selected Lot Quality Assurance Sampling (LQAS) to identify the variation in HF service quality am...

  8. A Method for Evaluating Quality Assurance Needs in Radiation Therapy

    International Nuclear Information System (INIS)

    The increasing complexity of modern radiation therapy planning and delivery techniques challenges traditional prescriptive quality control and quality assurance programs that ensure safety and reliability of treatment planning and delivery systems under all clinical scenarios. Until now quality management (QM) guidelines published by concerned organizations (e.g., American Association of Physicists in Medicine [AAPM], European Society for Therapeutic Radiology and Oncology [ESTRO], International Atomic Energy Agency [IAEA]) have focused on monitoring functional performance of radiotherapy equipment by measurable parameters, with tolerances set at strict but achievable values. In the modern environment, however, the number and sophistication of possible tests and measurements have increased dramatically. There is a need to prioritize QM activities in a way that will strike a balance between being reasonably achievable and optimally beneficial to patients. A systematic understanding of possible errors over the course of a radiation therapy treatment and the potential clinical impact of each is needed to direct limited resources in such a way to produce maximal benefit to the quality of patient care. Task Group 100 of the AAPM has taken a broad view of these issues and is developing a framework for designing QM activities, and hence allocating resources, based on estimates of clinical outcome, risk assessment, and failure modes. The report will provide guidelines on risk assessment approaches with emphasis on failure mode and effect analysis (FMEA) and an achievable QM program based on risk analysis. Examples of FMEA to intensity-modulated radiation therapy and high-dose-rate brachytherapy are presented. Recommendations on how to apply this new approach to individual clinics and further research and development will also be discussed

  9. Data Mining Methods Applied to Flight Operations Quality Assurance Data: A Comparison to Standard Statistical Methods

    Science.gov (United States)

    Stolzer, Alan J.; Halford, Carl

    2007-01-01

    In a previous study, multiple regression techniques were applied to Flight Operations Quality Assurance-derived data to develop parsimonious model(s) for fuel consumption on the Boeing 757 airplane. The present study examined several data mining algorithms, including neural networks, on the fuel consumption problem and compared them to the multiple regression results obtained earlier. Using regression methods, parsimonious models were obtained that explained approximately 85% of the variation in fuel flow. In general data mining methods were more effective in predicting fuel consumption. Classification and Regression Tree methods reported correlation coefficients of .91 to .92, and General Linear Models and Multilayer Perceptron neural networks reported correlation coefficients of about .99. These data mining models show great promise for use in further examining large FOQA databases for operational and safety improvements.

  10. Quality Assurance Program Plan for the Waste Sampling and Characterization Facility

    International Nuclear Information System (INIS)

    The objective of this Quality Assurance Plan is to provide quality assurance (QA) guidance, implementation of regulatory QA requirements, and quality control (QC) specifications for analytical service. This document follows the Department of Energy (DOE)-issued Hanford Analytical Services Quality Assurance Plan (HASQAP) and additional federal [10 US Code of Federal Regulations (CFR) 830.120] QA requirements that HASQAP does not cover. This document describes how the laboratory implements QA requirements to meet the federal or state requirements, provides what are the default QC specifications, and/or identifies the procedural information that governs how the laboratory operates. In addition, this document meets the objectives of the Quality Assurance Program provided in the WHC-CM-4-2, Section 2.1. This document also covers QA elements that are required in the Guidelines and Specifications for Preparing Quality Assurance Program Plans (QAPPs), (QAMS-004), and Interim Guidelines and Specifications for Preparing Quality Assurance Product Plans (QAMS-005) from the Environmental Protection Agency (EPA). A QA Index is provided in the Appendix A

  11. Quality Assurance Program Plan for the Waste Sampling and Characterization Facility

    Energy Technology Data Exchange (ETDEWEB)

    Grabbe, R.R.

    1995-03-02

    The objective of this Quality Assurance Plan is to provide quality assurance (QA) guidance, implementation of regulatory QA requirements, and quality control (QC) specifications for analytical service. This document follows the Department of Energy (DOE)-issued Hanford Analytical Services Quality Assurance Plan (HASQAP) and additional federal [10 US Code of Federal Regulations (CFR) 830.120] QA requirements that HASQAP does not cover. This document describes how the laboratory implements QA requirements to meet the federal or state requirements, provides what are the default QC specifications, and/or identifies the procedural information that governs how the laboratory operates. In addition, this document meets the objectives of the Quality Assurance Program provided in the WHC-CM-4-2, Section 2.1. This document also covers QA elements that are required in the Guidelines and Specifications for Preparing Quality Assurance Program Plans (QAPPs), (QAMS-004), and Interim Guidelines and Specifications for Preparing Quality Assurance Product Plans (QAMS-005) from the Environmental Protection Agency (EPA). A QA Index is provided in the Appendix A.

  12. Region III involvement in quality control and quality assurance of radon testing methods

    International Nuclear Information System (INIS)

    Region III has set a goal of increasing the testing for radon by our residents. One approach to this goal, is to bolster the public's confidence in the testing laboratories. We believe that this can be done most effectively by assuring the quality of the measurements available to the public. All Proficient Laboratories and Pennsylvania Certified Laboratories have submitted a quality assurance (QA) program. A QA audit checklist has been developed which will be finalized and made available to the states in our Region. This paper deals with inspection, verification, and documentation of the various laboratories and their compliance with prudent measuring protocols and addresses the following items: Organization and responsibilities; Sampling procedures; Detector chain of custody; Measurement procedures, quality control checks; State certification and RMP; Data resection, validation, and reporting; Quality assurance reports to management; Interview and discussion of QA audit with responsible officer

  13. Coupling methods for multistage sampling

    OpenAIRE

    Chauvet, Guillaume

    2015-01-01

    Multistage sampling is commonly used for household surveys when there exists no sampling frame, or when the population is scattered over a wide area. Multistage sampling usually introduces a complex dependence in the selection of the final units, which makes asymptotic results quite difficult to prove. In this work, we consider multistage sampling with simple random without replacement sampling at the first stage, and with an arbitrary sampling design for further stages. We consider coupling ...

  14. Towards Cost-efficient Sampling Methods

    OpenAIRE

    Peng, Luo; Yongli, Li; Chong, Wu

    2014-01-01

    The sampling method has been paid much attention in the field of complex network in general and statistical physics in particular. This paper presents two new sampling methods based on the perspective that a small part of vertices with high node degree can possess the most structure information of a network. The two proposed sampling methods are efficient in sampling the nodes with high degree. The first new sampling method is improved on the basis of the stratified random sampling method and...

  15. Quality assurance manual plutonium liquid scintillation methods and procedures

    International Nuclear Information System (INIS)

    Nose swipe analysis is a very important tool for Radiation Protection personnel. Nose swipe analysis is a very fast and accurate method for (1) determining if a worker has been exposed to airborne plutonium contamination and (2) Identifying the area where there has been a possible plutonium release. Liquid scintillation analysis techniques have been effectively applied to accurately determine the plutonium alpha activity on nose swipe media. Whatman-40 paper and Q-Tips are the only two media which have been evaluated and can be used for nose swipe analysis. Presently, only Q-Tips are used by Group HSE-1 Radiation Protection Personnel. However, both swipe media will be discussed in this report

  16. Quality assurance exercise for estimating low-levels of alpha emitters in urine samples: performance of Trombay's bioassay laboratory

    International Nuclear Information System (INIS)

    As a part of quality assurance, Trombay's bioassay laboratory took part in the international intercomparison exercise organized by International Atomic Energy Agency (IAEA) for estimating low-levels of alpha emitters (234U, 238U, 239+240Pu and 241Am) in urine samples. In this paper, performance of the Trombay's bioassay laboratory in the intercomparison exercise is presented. The results submitted by the laboratory were found to be in good agreement with the organizers (spiked) values. (author)

  17. Comparison of various monitoring methods for quality assurance purposes at Thoriated electrode production

    International Nuclear Information System (INIS)

    Raw material for Thoriated electrodes is a powder mixture of pure Tungsten and about one to five percent of Thoriumdioxide. The mixture has to be pressed and sintered. At all these work sites, Thorium could be emitted. Thorium exposure measurements described in the literature show significant differences in the results of stationary and personal air sampling measurements on the one side and excretion measurements on the other side. These discrepancies were the motivation for an extensive measurement program, wherein all available monitoring methods should be compared for quality assurance purposes. The investigated plant was chosen for this measurement program, because the described handlings occur only two times a year for two weeks each. Long term Thorium depositions, which would disturb the interpretation of excretion monitoring measurements, could be neglected therefore. Six volunteer persons were equipped with personal air sampling pumps. Some of these samplings were taken twice at the same person during the same period and analyzed by two different institutions for comparison purposes. Stationary air samplings had been done in the vicinity during the same sampling periods. The filters were analyzed by neutron activation analysis. Urine- and faeces excretion measurements had been taken before, during and after the exposure period. These samples were divided into two parts and analyzed by two methods (ICP-MS and Alpha-spectrometry) by four different institutions. Additional exhalation measurements had been performed. The comparison of the results from personal air monitoring showed a maximum difference of a factor of two. Other samples taken with stationary sampling pumps and at the same period, showed a maximum difference of a factor of five. But the results from stationary sampling and personal sampling varies up to a factor of 200. The mean value of personal determined activity concentration is 50 mBq m-3 and the mean value determined by stationary sampling

  18. Improving data quality and supervision of antiretroviral therapy sites in Malawi: an application of Lot Quality Assurance Sampling

    Directory of Open Access Journals (Sweden)

    Hedt-Gauthier Bethany L

    2012-07-01

    Full Text Available Abstract Background High quality program data is critical for managing, monitoring, and evaluating national HIV treatment programs. By 2009, the Malawi Ministry of Health had initiated more than 270,000 patients on HIV treatment at 377 sites. Quarterly supervision of these antiretroviral therapy (ART sites ensures high quality care, but the time currently dedicated to exhaustive record review and data cleaning detracts from other critical components. The exhaustive record review is unlikely to be sustainable long term because of the resources required and increasing number of patients on ART. This study quantifies the current levels of data quality and evaluates Lot Quality Assurance Sampling (LQAS as a tool to prioritize sites with low data quality, thus lowering costs while maintaining sufficient quality for program monitoring and patient care. Methods In January 2010, a study team joined supervision teams at 19 sites purposely selected to reflect the variety of ART sites. During the exhaustive data review, the time allocated to data cleaning and data discrepancies were documented. The team then randomly sampled 76 records from each site, recording secondary outcomes and the time required for sampling. Results At the 19 sites, only 1.2% of records had discrepancies in patient outcomes and 0.4% in treatment regimen. However, data cleaning took 28.5 hours in total, suggesting that data cleaning for all 377 ART sites would require over 350 supervision-hours quarterly. The LQAS tool accurately identified the sites with the low data quality, reduced the time for data cleaning by 70%, and allowed for reporting on secondary outcomes. Conclusions Most sites maintained high quality records. In spite of this, data cleaning required significant amounts of time with little effect on program estimates of patient outcomes. LQAS conserves resources while maintaining sufficient data quality for program assessment and management to allow for quality patient

  19. Quality assurance program for determining the radioactivity in environmental samples at the Institute of Nuclear Energy Research in Taiwan

    International Nuclear Information System (INIS)

    Interest in determining radioactivity in environmental samples has increased considerably in recent years after the Chernobyl accident in 1986. Environmental monitoring programs have been set up in different countries to measure the trace amount of radionuclides in the environment, and quality of the analytical results on these samples is important because the regulation and safety concerns. A good quality assurance program is essential to provide accurate information for the regulatory body and environmentalists to set proper reactions to protect the environment, and a good analytical result is also important for scientists to determine the transfer of radionuclides between environmental matrices. The Institute of Nuclear Energy Research (lNER) in Taiwan has been working on radionuclide analysis in environmental samples for years, and it's environmental media radioanalytical laboratory (EMRAL) has recently upgraded its quality assurance program for the international standard ISO/lEC guide 25 requirements. The general requirements of lSO/lEC guide 25 has been adapted by the Chinese National Laboratory Accreditation (CNLA) of Taiwan, and CNLA is also a member of International Laboratory Accreditation Cooperation (ILAC) and Asia Pacific Laboratory Accreditation Cooperation (APLAC). This paper summarizes the quality assurance program of lNER's EMRAL. It covers both management and technical sections. These sections have ensured the quality of INER's EMRAL, and they can be applied to different laboratories in the future. (author)

  20. Assessing Local Risk of Rifampicin-Resistant Tuberculosis in KwaZulu-Natal, South Africa Using Lot Quality Assurance Sampling

    Science.gov (United States)

    Heidebrecht, Christine L.; Podewils, Laura J.; Pym, Alexander; Mthiyane, Thuli; Cohen, Ted

    2016-01-01

    Background KwaZulu-Natal (KZN) has the highest burden of notified multidrug-resistant tuberculosis (MDR TB) and extensively drug-resistant (XDR) TB cases in South Africa. A better understanding of spatial heterogeneity in the risk of drug-resistance may help to prioritize local responses. Methods Between July 2012 and June 2013, we conducted a two-way Lot Quality Assurance Sampling (LQAS) study to classify the burden of rifampicin (RIF)-resistant TB among incident TB cases notified within the catchment areas of seven laboratories in two northern and one southern district of KZN. Decision rules for classification of areas as having either a high- or low-risk of RIF resistant TB (based on proportion of RIF resistance among all TB cases) were based on consultation with local policy makers. Results We classified five areas as high-risk and two as low-risk. High-risk areas were identified in both Southern and Northern districts, with the greatest proportion of RIF resistance observed in the northernmost area, the Manguzi community situated on the Mozambique border. Conclusion Our study revealed heterogeneity in the risk of RIF resistant disease among incident TB cases in KZN. This study demonstrates the potential for LQAS to detect geographic heterogeneity in areas where access to drug susceptibility testing is limited. PMID:27050561

  1. Sample processing device and method

    DEFF Research Database (Denmark)

    2011-01-01

    A sample processing device is disclosed, which sample processing device comprises a first substrate and a second substrate, where the first substrate has a first surface comprising two area types, a first area type with a first contact angle with water and a second area type with a second contact...

  2. Comparison of sampling methods for animal manure

    OpenAIRE

    Derikx, P. J. L.; Ogink, N.W.M.; Hoeksma, P.

    1997-01-01

    Currently available and recently developed sampling methods for slurry and solid manure were tested for bias and reproducibility in the determination of total phosphorus and nitrogen content of samples. Sampling methods were based on techniques in which samples were taken either during loading from the hose or from the transport vehicle after loading. Most methods were unbiased. New sampling methods for slurry from the hose were substantially more reproducible than existing methods. For pract...

  3. Quality assurance and quality control for thermal/optical analysis of aerosol samples for organic and elemental carbon.

    Science.gov (United States)

    Chow, Judith C; Watson, John G; Robles, Jerome; Wang, Xiaoliang; Chen, L-W Antony; Trimble, Dana L; Kohl, Steven D; Tropp, Richard J; Fung, Kochy K

    2011-12-01

    Accurate, precise, and valid organic and elemental carbon (OC and EC, respectively) measurements require more effort than the routine analysis of ambient aerosol and source samples. This paper documents the quality assurance (QA) and quality control (QC) procedures that should be implemented to ensure consistency of OC and EC measurements. Prior to field sampling, the appropriate filter substrate must be selected and tested for sampling effectiveness. Unexposed filters are pre-fired to remove contaminants and acceptance tested. After sampling, filters must be stored in the laboratory in clean, labeled containers under refrigeration (carbon analyses, periodic QC tests include calibration of the flame ionization detector with different types of carbon standards, thermogram inspection, replicate analyses, quantification of trace oxygen concentrations (helium atmosphere, and calibration of the sample temperature sensor. These established QA/QC procedures are applicable to aerosol sampling and analysis for carbon and other chemical components. PMID:21626190

  4. Paediatric rehabilitation treatment standards: a method for quality assurance in Germany

    OpenAIRE

    2014-01-01

    Over the last few years, the German Pension Insurance has implemented a new method of quality assurance for inpatient rehabilitation of children and adolescents diagnosed with bronchial asthma, obesity, or atopic dermatitis: the so-called rehabilitation treatment standards (RTS). They aim at promoting a comprehensive and evidence-based care in rehabilitation. Furthermore, they are intended to make the therapeutic processes in medical rehabilitation as well as potential deficits more transpare...

  5. Quality assurance

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, B.M.; Gleckler, B.P.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the quality assurance and quality control practices of Hanford Site environmental monitoring and surveillance programs. Samples are analyzed according to documented standard analytical procedures. This section discusses specific measures taken to ensure quality in project management, sample collection, and analytical results.

  6. Quality assurance requirements and methods for high level waste package acceptability

    International Nuclear Information System (INIS)

    This document should serve as guidance for assigning the necessary items to control the conditioning process in such a way that waste packages are produced in compliance with the waste acceptance requirements. It is also provided to promote the exchange of information on quality assurance requirements and on the application of quality assurance methods associated with the production of high level waste packages, to ensure that these waste packages comply with the requirements for transportation, interim storage and waste disposal in deep geological formations. The document is intended to assist both the operators of conditioning facilities and repositories as well as national authorities and regulatory bodies, involved in the licensing of the conditioning of high level radioactive wastes or in the development of deep underground disposal systems. The document recommends the quality assurance requirements and methods which are necessary to generate data for these parameters identified in IAEA-TECDOC-560 on qualitative acceptance criteria, and indicates where and when the control methods can be applied, e.g. in the operation or commissioning of a process or in the development of a waste package design. Emphasis is on the control of the process and little reliance is placed on non-destructive or destructive testing. Qualitative criteria, relevant to disposal of high level waste, are repository dependent and are not addressed here. 37 refs, 3 figs, 2 tabs

  7. Application of software quality assurance methods in validation and maintenance of reactor analysis computer codes

    International Nuclear Information System (INIS)

    Various computer codes employed at Israel Electricity Company for preliminary reactor design analysis and fuel cycle scoping calculations have been often subject to program source modifications. Although most changes were due to computer or operating system compatibility problems, a number of significant modifications were due to model improvement and enhancements of algorithm efficiency and accuracy. With growing acceptance of software quality assurance requirements and methods, a program of implementing extensive testing of modified software has been adopted within the regular maintenance activities. In this work survey has been performed of various software quality assurance methods of software testing which belong mainly to the two major categories of implementation ('white box') and specification-based ('black box') testing. The results of this survey exhibits a clear preference of specification-based testing. In particular the equivalence class partitioning method and the boundary value method have been selected as especially suitable functional methods for testing reactor analysis codes.A separate study of software quality assurance methods and techniques has been performed in this work objective to establish appropriate pre-test software specification methods. Two methods of software analysis and specification have been selected as the most suitable for this purpose: The method of data flow diagrams has been shown to be particularly valuable for performing the functional/procedural software specification while the entities - relationship diagrams has been approved to be efficient for specifying software data/information domain. Feasibility of these two methods has been analyzed in particular for software uncertainty analysis and overall code accuracy estimation. (author). 14 refs

  8. Paediatric rehabilitation treatment standards: a method for quality assurance in Germany

    Directory of Open Access Journals (Sweden)

    Jutta Ahnert

    2014-07-01

    Full Text Available Over the last few years, the German Pension Insurance has implemented a new method of quality assurance for inpatient rehabilitation of children and adolescents diagnosed with bronchial asthma, obesity, or atopic dermatitis: the so-called rehabilitation treatment standards (RTS. They aim at promoting a comprehensive and evidence-based care in rehabilitation. Furthermore, they are intended to make the therapeutic processes in medical rehabilitation as well as potential deficits more transparent. The development of RTS was composed of five phases during which current scientific evidence, expert knowledge, and patient expectations were included. Their core element is the specification of evidence-based treatment modules that describe a good rehabilitation standard for children diagnosed with bronchial asthma, obesity, or atopic dermatitis. Opportunities and limitations of the RTS as a tool for quality assurance are discussed.

  9. The integrated performance evaluation program quality assurance guidance in support of EM environmental sampling and analysis activities

    International Nuclear Information System (INIS)

    EM's (DOE's Environmental Restoration and Waste Management) Integrated Performance Evaluation Program (IPEP) has the purpose of integrating information from existing PE programs with expanded QA activities to develop information about the quality of radiological, mixed waste, and hazardous environmental sample analyses provided by all laboratories supporting EM programs. The guidance addresses the goals of identifying specific PE sample programs and contacts, identifying specific requirements for participation in DOE's internal and external (regulatory) programs, identifying key issues relating to application and interpretation of PE materials for EM headquarters and field office managers, and providing technical guidance covering PE materials for site-specific activities. (PE) Performance Evaluation materials or samples are necessary for the quality assurance/control programs covering environmental data collection

  10. Countdown to 2015: Tracking Maternal and Child Health Intervention Targets Using Lot Quality Assurance Sampling in Bauchi State Nigeria

    Science.gov (United States)

    Abegunde, Dele; Orobaton, Nosa

    2015-01-01

    Background Improving maternal and child health remains a top priority in Nigeria’s Bauchi State in the northeastern region where the maternal mortality ratio (MMR) and infant mortality rate (IMR) are as high as 1540 per 100,000 live births and 78 per 1,000 live births respectively. In this study, we used the framework of the continuum of maternal and child care to evaluate the impact of interventions in Bauchi State focused on improved maternal and child health, and to ascertain progress towards the achievement of Millennium Development Goals (MDGs) 4 and 5. Methods At baseline (2012) and then at follow-up (2013), we randomly sampled 340 households from 19 random locations in each of the 20 Local Government Areas (LGA) of Bauchi State in Northern Nigeria, using the Lot Quality Assurance Sampling (LQAS) technique. Women residents in the households were interviewed about their own health and that of their children. Estimated LGA coverage of maternal and child health indicators were aggregated across the State. These values were then compared to the national figures, and the differences from 2012 to 2014 were calculated. Results For several of the indicators, a modest improvement from baseline was found. However, the indicators in the continuum of care neither reached the national average nor attained the 90% globally recommended coverage level. The majority of the LGA surveyed were classifiable as high priority, thus requiring intensified efforts and programmatic scale up. Conclusions Intensive scale-up of programs and interventions is needed in Bauchi State, Northern Nigeria, to accelerate, consolidate and sustain the modest but significant achievements in the continuum of care, if MDGs 4 and 5 are to be achieved by the end of 2015. The intentional focus of LGAs as the unit of intervention ought to be considered a condition precedent for future investments. Priority should be given to the re-allocating resources to program areas and regions where coverage has been

  11. Sampling method of environmental radioactivity monitoring

    International Nuclear Information System (INIS)

    This manual provides sampling methods of environmental samples of airborne dust, precipitated dust, precipitated water (rain or snow), fresh water, soil, river sediment or lake sediment, discharged water from a nuclear facility, grains, tea, milk, pasture grass, limnetic organisms, daily diet, index organisms, sea water, marine sediment, marine organisms, and that for tritium and radioiodine determination for radiation monitoring from radioactive fallout or radioactivity release by nuclear facilities. This manual aims at the presentation of standard sampling procedures for environmental radioactivity monitoring regardless of monitoring objectives, and shows preservation method of environmental samples acquired at the samplingpoint for radiation counting for those except human body. Sampling techniques adopted in this manual is decided by the criteria that they are suitable for routine monitoring and any special skillfulness is not necessary. Based on the above-mentioned principle, this manual presents outline and aims of sampling, sampling position or object, sampling quantity, apparatus, equipment or vessel for sampling, sampling location, sampling procedures, pretreatment and preparation procedures of a sample for radiation counting, necessary recording items for sampling and sample transportation procedures. Special attention is described in the chapter of tritium and radioiodine because these radionuclides might be lost by the above-mentioned sample preservation method for radiation counting of less volatile radionuclides than tritium or radioiodine. (Takagi, S.)

  12. Subrandom methods for multidimensional nonuniform sampling

    Science.gov (United States)

    Worley, Bradley

    2016-08-01

    Methods of nonuniform sampling that utilize pseudorandom number sequences to select points from a weighted Nyquist grid are commonplace in biomolecular NMR studies, due to the beneficial incoherence introduced by pseudorandom sampling. However, these methods require the specification of a non-arbitrary seed number in order to initialize a pseudorandom number generator. Because the performance of pseudorandom sampling schedules can substantially vary based on seed number, this can complicate the task of routine data collection. Approaches such as jittered sampling and stochastic gap sampling are effective at reducing random seed dependence of nonuniform sampling schedules, but still require the specification of a seed number. This work formalizes the use of subrandom number sequences in nonuniform sampling as a means of seed-independent sampling, and compares the performance of three subrandom methods to their pseudorandom counterparts using commonly applied schedule performance metrics. Reconstruction results using experimental datasets are also provided to validate claims made using these performance metrics.

  13. Methods and quality assurance in environmental medicine. Formation of a RKI-Commission

    International Nuclear Information System (INIS)

    An almost bewildering number of widely differing methods and techniques, often not validated, are being applied often inappropriately in the field of environmental medicine to answer questions regarding exposure assessment, diagnosis, treatment, counselling and prevention. Therefore, quality control within the field of environmental medicine is quite problematic. A primary goal of the newly formed RKI-Commission 'Methods and Quality Assurance in Environmental Medicine' is to form a panel of experts in the field, who evaluate the situation and generate consensus documents containing respective recommendations. By this the commission will contribute to standardization and agreement on appropriate methods, procedures and their correct application in the practice of environmental medicine. Hopefully it will also achieve a stronger, more consistent use of evidence-based-medicine and improve the quality of the structure, processes and results of research and practice in this field. The committee will initially deal with the issue of clinical environmental medicine, because here the largest problems in quality assurance are seen. In this context the commission will look at the problem areas of environmental-medical outpatient units and environmental clinics. The work of the commission will be supported by the newly formed Documentation and Evaluation Center for Methods in Environmental Medicine (Zentrale Erfassungs- und Bewertungsstelle fuer umweltmedizinische Methoden, ZEBUM) at the Robert Koch Institute. (orig.)

  14. Quality assurance methods for some agents used in PET studies of the dopaminergic system

    International Nuclear Information System (INIS)

    In the authors' laboratory, quality assurance rests on establishing good manufacturing practice supported by routine quality control. In establishing good manufacturing practice, indirect techniques (e.g. NMR spectroscopy) and direct techniques (e.g. radiochromatography) are extensively applied to characterize the product from a developing procedure, and to investigate any contamination. In order to establish radiochemical purity, chemical purity, and specific activity before radiopharmaceutical product administration, they have developed rapid routine quality control procedures based on analytical HPLC methods for L-6-[18F]fluoro-DOPA, S-[N-methyl-11C]nomifensine, and [O-methyl-11C]raclopride

  15. Mixed Methods Sampling: A Typology with Examples

    Science.gov (United States)

    Teddlie, Charles; Yu, Fen

    2007-01-01

    This article presents a discussion of mixed methods (MM) sampling techniques. MM sampling involves combining well-established qualitative and quantitative techniques in creative ways to answer research questions posed by MM research designs. Several issues germane to MM sampling are presented including the differences between probability and…

  16. ALARA ASSESSMENT OF SETTLER SLUDGE SAMPLING METHODS

    International Nuclear Information System (INIS)

    The purpose of this assessment is to compare underwater and above water settler sludge sampling methods to determine if the added cost for underwater sampling for the sole purpose of worker dose reductions is justified. Initial planning for sludge sampling included container, settler and knock-out-pot (KOP) sampling. Due to the significantly higher dose consequence of KOP sludge, a decision was made to sample KOP underwater to achieve worker dose reductions. Additionally, initial plans were to utilize the underwater sampling apparatus for settler sludge. Since there are no longer plans to sample KOP sludge, the decision for underwater sampling for settler sludge needs to be revisited. The present sampling plan calls for spending an estimated $2,500,000 to design and construct a new underwater sampling system (per A21 C-PL-001 RevOE). This evaluation will compare and contrast the present method of above water sampling to the underwater method that is planned by the Sludge Treatment Project (STP) and determine if settler samples can be taken using the existing sampling cart (with potentially minor modifications) while maintaining doses to workers As Low As Reasonably Achievable (ALARA) and eliminate the need for costly redesigns, testing and personnel retraining

  17. [A method for quality assurance in a community mental health center. Community psychiatry in Copenhagen].

    Science.gov (United States)

    Vendsborg, P B; Garsdal, O; Knudsen, H C

    1998-03-16

    The purpose was to describe a method for quality assurance in community mental health centres. Three psychiatrists and a multiprofessional treatment team conceived the method. The community mental health center--which was the basis for the work--was the Copenhagen centre for the sectors Vesterbro and Kongens Enghave. The target group for the centre is people with serious mental illness. The work is done according to the principles for clinical case managers. Data are registered in a national database in combination with the centre's own registration system. Eleven indicators for process quality and eight for outcome quality were selected. Measurement parameters for there indicators were defined. Criteria and standard were defined according to existing knowledge and the author's clinical experience. The necessary programs for calculating the value of the chosen standards are constructed. With the use of existing data and a limited extra registration it was possible to evolve a method for quality assurance in a community mental health centre. PMID:9536637

  18. Reducing the risk of failure: Software Quality assurance standards and methods

    International Nuclear Information System (INIS)

    An effective Software Quality Assurance (SQA) program provides an overall approach to software engineering and the establishment of proven methods for the production of reliable software. And, in the authors experience, the overall costs for the software life are diminished with the application of quality methods. In their experience, the issues for implementing quality standards and practices are many. This paper addresses those issues as well as the lessons learned from developing and implementing a number of software quality assurance programs. Their experience includes the development and implementation of their own NRC accepted SQA program and an SQA program for an engineering software developer, as well as developing SQA procedures, standards, and methods for utilities, medical and commercial clients. Some of the issues addressed in this paper are: setting goals and defining quality; applying the software life cycle; addressing organizational issues; providing flexibility and increasing productivity; producing effective documentation; maintaining quality records; Imposing software configuration management; conducting reviews, audits, and controls; verification and validation; and controlling software procurement

  19. A method for assurance of image integrity in CAD-PACS integration

    Science.gov (United States)

    Zhou, Zheng

    2007-03-01

    Computer Aided Detection/Diagnosis (CAD) can greatly assist in the clinical decision making process, and therefore, has drawn tremendous research efforts. However, integrating independent CAD workstation results with the clinical diagnostic workflow still remains challenging. We have presented a CAD-PACS integration toolkit that complies with DICOM standard and IHE profiles. One major issue in CAD-PACS integration is the security of the images used in CAD post-processing and the corresponding CAD result images. In this paper, we present a method for assuring the integrity of both DICOM images used in CAD post-processing and the CAD image results that are in BMP or JPEG format. The method is evaluated in a PACS simulator that simulates clinical PACS workflow. It can also be applied to multiple CAD applications that are integrated with the PACS simulator. The successful development and evaluation of this method will provide a useful approach for assuring image integrity of the CAD-PACS integration in clinical diagnosis.

  20. Transuranic waste characterization sampling and analysis methods manual. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Suermann, J.F.

    1996-04-01

    This Methods Manual provides a unified source of information on the sampling and analytical techniques that enable Department of Energy (DOE) facilities to comply with the requirements established in the current revision of the Transuranic Waste Characterization Quality Assurance Program Plan (QAPP) for the Waste Isolation Pilot Plant (WIPP) Transuranic (TRU) Waste Characterization Program (the Program) and the WIPP Waste Analysis Plan. This Methods Manual includes all of the testing, sampling, and analytical methodologies accepted by DOE for use in implementing the Program requirements specified in the QAPP and the WIPP Waste Analysis Plan. The procedures in this Methods Manual are comprehensive and detailed and are designed to provide the necessary guidance for the preparation of site-specific procedures. With some analytical methods, such as Gas Chromatography/Mass Spectrometry, the Methods Manual procedures may be used directly. With other methods, such as nondestructive characterization, the Methods Manual provides guidance rather than a step-by-step procedure. Sites must meet all of the specified quality control requirements of the applicable procedure. Each DOE site must document the details of the procedures it will use and demonstrate the efficacy of such procedures to the Manager, National TRU Program Waste Characterization, during Waste Characterization and Certification audits.

  1. Transuranic waste characterization sampling and analysis methods manual. Revision 1

    International Nuclear Information System (INIS)

    This Methods Manual provides a unified source of information on the sampling and analytical techniques that enable Department of Energy (DOE) facilities to comply with the requirements established in the current revision of the Transuranic Waste Characterization Quality Assurance Program Plan (QAPP) for the Waste Isolation Pilot Plant (WIPP) Transuranic (TRU) Waste Characterization Program (the Program) and the WIPP Waste Analysis Plan. This Methods Manual includes all of the testing, sampling, and analytical methodologies accepted by DOE for use in implementing the Program requirements specified in the QAPP and the WIPP Waste Analysis Plan. The procedures in this Methods Manual are comprehensive and detailed and are designed to provide the necessary guidance for the preparation of site-specific procedures. With some analytical methods, such as Gas Chromatography/Mass Spectrometry, the Methods Manual procedures may be used directly. With other methods, such as nondestructive characterization, the Methods Manual provides guidance rather than a step-by-step procedure. Sites must meet all of the specified quality control requirements of the applicable procedure. Each DOE site must document the details of the procedures it will use and demonstrate the efficacy of such procedures to the Manager, National TRU Program Waste Characterization, during Waste Characterization and Certification audits

  2. Application of Sampling Methods to Geological Survey

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@There are two kinds of research methods in geological observation study. One is the remote-sensing observation. The other is the partial sampling method extensively used in every stage of the geological work, for example, in arranging the lines and points of geologic survey, and in arranging the exploration engineering. Three problems may occur in practical application of the sampling method: (1) Though we use the partial sampling method in geological work, we must make use of many labor powers, materials and money to accomplish the geological task. Is the method we use appropriate to some special geological task? (2) How many samples or observation points should be appropriate to the geological research?

  3. Fluidics platform and method for sample preparation

    Energy Technology Data Exchange (ETDEWEB)

    Benner, Henry W.; Dzenitis, John M.

    2016-06-21

    Provided herein are fluidics platforms and related methods for performing integrated sample collection and solid-phase extraction of a target component of the sample all in one tube. The fluidics platform comprises a pump, particles for solid-phase extraction and a particle-holding means. The method comprises contacting the sample with one or more reagents in a pump, coupling a particle-holding means to the pump and expelling the waste out of the pump while the particle-holding means retains the particles inside the pump. The fluidics platform and methods herein described allow solid-phase extraction without pipetting and centrifugation.

  4. Quality assurance for 14C and 3H measurements by GPC and LSC counting methods in the Zagreb Laboratory

    International Nuclear Information System (INIS)

    Laboratory for Measurements of Low-level Radioactivity of the Rudjer Boskovic Institute in Zagreb, Croatia, has been measuring 14C since 1968 and 3H since 1976 by applying gas (CH4) proportional counting (GPC) technique. By purchasing a Quantulus 1220 ultra low-level liquid scintillation counter (LSC) in 2002 two methods of chemical preparation of 14C samples have been implemented: a CO2 absorption method and a benzene synthesis method. The procedures for LSC measurement of both isotopes have been established. A 'good laboratory practice' was introduced since the beginning of the measurements in the Laboratory. The Laboratory Manual issued in 1994 covered most technical procedures required by the QC/QA system and management, including calibration of measurements, traceability, trackability and statistical evaluation of results. Laboratory participated in 4 radiocarbon and five tritium interlaboratory comparisons. A great progress in implementation of quality system was achieved during the participation in the IAEA project RER/2/004 'Quality Control and Quality Assurance of Nuclear Analytical Techniques' (1999-2001). The new Quality Assurance Manual includes the following documents conformed with ISO 17025 requirements: 6 administrative documents, 3 technical documents, 5 administrative procedures, 14 technical procedures, 3 documents of method validations, description of 3 programs and databases, 12 forms, 14 log books, 2 action plans, 3 lists of equipment and expenditures, and documentation on Laboratory personnel. Laboratory took part in three IAEA audits and two proficiency tests, and a constant progress was established. During the participation in the IAEA project a specific problem was the non-existence of implementation of quality system at the Institute level. Last year a new quality manager of the Institute was designated and the first version of the new Institute Quality Manual in accordance with ISO 17025 requirements was issued. Harmonization of the

  5. Innovative methods for inorganic sample preparation

    International Nuclear Information System (INIS)

    Procedures and guidelines are given for the dissolution of a variety of selected materials using fusion, microwave, and Parr bomb techniques. These materials include germanium glass, corium-concrete mixtures, and zeolites. Emphasis is placed on sample-preparation approaches that produce a single master solution suitable for complete multielement characterization of the sample. In addition, data are presented on the soil microwave digestion method approved by the Environmental Protection Agency (EPA). Advantages and disadvantages of each sample-preparation technique are summarized

  6. Waveform sample method of excitable sensory neuron

    OpenAIRE

    Wang, Sheng-Jun; Xu, Xin-Jian; Wang, Ying-Hai

    2006-01-01

    We present a new interpretation for encoding information of the period of input signals into spike-trains in individual sensory neuronal systems. The spike-train could be described as the waveform sample of the input signal which locks sample points to wave crests with randomness. Based on simulations of the Hodgkin-Huxley (HH) neuron responding to periodic inputs, we demonstrate that the random sampling is a proper encoding method in medium frequency region since power spectra of the reconst...

  7. QUALITY ASSURANCE UPDATE

    Science.gov (United States)

    An overview of the air pollution quality assurance program as implemented by EMSL/RTP is presented. The discussion includes method standardization operations for both ambient air and stationary source measurements, the quality assurance audit program, the ambient air equivalency ...

  8. Private sector delivery of health services in developing countries: a mixed-methods study on quality assurance in social franchises

    Directory of Open Access Journals (Sweden)

    Schlein Karen

    2013-01-01

    Full Text Available Abstract Background Across the developing world health care services are most often delivered in the private sector and social franchising has emerged, over the past decade, as an increasingly popular method of private sector health care delivery. Social franchising aims to strengthen business practices through economies of scale: branding clinics and purchasing drugs in bulk at wholesale prices. While quality is one of the established goals of social franchising, there is no published documentation of how quality levels might be set in the context of franchised private providers, nor what quality assurance measures can or should exist within social franchises. The aim of this study was to better understand the quality assurance systems currently utilized in social franchises, and to determine if there are shared standards for practice or quality outcomes that exist across programs. Methods The study included three data sources and levels of investigation: 1 Self-reported program data; 2 Scoping telephone interviews; and 3 In-depth field interviews and clinic visits. Results Social Franchises conceive of quality assurance not as an independent activity, but rather as a goal that is incorporated into all areas of franchise operations, including recruitment, training, monitoring of provider performance, monitoring of client experience and the provision of feedback. Conclusions These findings are the first evidence to support the 2002 conceptual model of social franchising which proposed that the assurance of quality was one of the three core goals of all social franchises. However, while quality is important to franchise programs, quality assurance systems overall are not reflective of the evidence to-date on quality measurement or quality improvement best practices. Future research in this area is needed to better understand the details of quality assurance systems as applied in social franchise programs, the process by which quality assurance

  9. Analytical laboratory quality assurance guidance in support of EM environmental sampling and analysis activities

    International Nuclear Information System (INIS)

    This document introduces QA guidance pertaining to design and implementation of laboratory procedures and processes for collecting DOE Environmental Restoration and Waste Management (EM) ESAA (environmental sampling and analysis activities) data. It addresses several goals: identifying key laboratory issues and program elements to EM HQ and field office managers; providing non-prescriptive guidance; and introducing environmental data collection program elements for EM-263 assessment documents and programs. The guidance describes the implementation of laboratory QA elements within a functional QA program (development of the QA program and data quality objectives are not covered here)

  10. Analytical laboratory quality assurance guidance in support of EM environmental sampling and analysis activities

    Energy Technology Data Exchange (ETDEWEB)

    1994-05-01

    This document introduces QA guidance pertaining to design and implementation of laboratory procedures and processes for collecting DOE Environmental Restoration and Waste Management (EM) ESAA (environmental sampling and analysis activities) data. It addresses several goals: identifying key laboratory issues and program elements to EM HQ and field office managers; providing non-prescriptive guidance; and introducing environmental data collection program elements for EM-263 assessment documents and programs. The guidance describes the implementation of laboratory QA elements within a functional QA program (development of the QA program and data quality objectives are not covered here).

  11. Very accurate (definitive) methods by radiochemical NAA and their significance for quality assurance in trace analysis

    International Nuclear Information System (INIS)

    The idea of very accurate (definitive) methods by RNAA for the determination of individual trace elements in selected matrices is presented. The approach is based on combination of neutron activation with selective and truly quantitative post-irradiation isolation of an indicator radionuclide by column chromatography followed by high resolution γ-ray spectrometric measurement. The method should be, in principle, a single element method to optimize all conditions with respect to determination of this particular element. Radiochemical separation scheme should assure separation of the analyte from practically all accompanying radionuclides to provide interference-free γ-ray spectrometric measurement and achieving best detection limits. The method should have some intrinsic mechanisms incorporated into the procedure preventing any possibility of making gross errors. Several criteria were formulated which must be simultaneously fulfilled in order to acknowledge the analytical result as obtained by definitive method. Such methods are not intended for routine measurements but rather for verifying the accuracy of other methods of analysis and certification of the candidate reference materials. The usefulness of such methods is illustrated on the example of Cd and references are given to similar methods elaborated for the determination of several other elements (Co, Cu, Mo, Ni and U) in biological materials. (author)

  12. Sample preparation method for scanning force microscopy

    CERN Document Server

    Jankov, I R; Szente, R N; Carreno, M N P; Swart, J W; Landers, R

    2001-01-01

    We present a method of sample preparation for studies of ion implantation on metal surfaces. The method, employing a mechanical mask, is specially adapted for samples analysed by Scanning Force Microscopy. It was successfully tested on polycrystalline copper substrates implanted with phosphorus ions at an acceleration voltage of 39 keV. The changes of the electrical properties of the surface were measured by Kelvin Probe Force Microscopy and the surface composition was analysed by Auger Electron Spectroscopy.

  13. Statistical methods for quality assurance basics, measurement, control, capability, and improvement

    CERN Document Server

    Vardeman, Stephen B

    2016-01-01

    This undergraduate statistical quality assurance textbook clearly shows with real projects, cases and data sets how statistical quality control tools are used in practice. Among the topics covered is a practical evaluation of measurement effectiveness for both continuous and discrete data. Gauge Reproducibility and Repeatability methodology (including confidence intervals for Repeatability, Reproducibility and the Gauge Capability Ratio) is thoroughly developed. Process capability indices and corresponding confidence intervals are also explained. In addition to process monitoring techniques, experimental design and analysis for process improvement are carefully presented. Factorial and Fractional Factorial arrangements of treatments and Response Surface methods are covered. Integrated throughout the book are rich sets of examples and problems that help readers gain a better understanding of where and how to apply statistical quality control tools. These large and realistic problem sets in combination with the...

  14. A method of setting limits for the purpose of quality assurance

    International Nuclear Information System (INIS)

    The result from any assurance measurement needs to be checked against some limits for acceptability. There are two types of limits; those that define clinical acceptability (action limits) and those that are meant to serve as a warning that the measurement is close to the action limits (tolerance limits). Currently, there is no standard procedure to set these limits. In this work, we propose an operational procedure to set tolerance limits and action limits. The approach to establish the limits is based on techniques of quality engineering using control charts and a process capability index. The method is different for tolerance limits and action limits with action limits being categorized into those that are specified and unspecified. The procedure is to first ensure process control using the I-MR control charts. Then, the tolerance limits are set equal to the control chart limits on the I chart. Action limits are determined using the Cpm process capability index with the requirements that the process must be in-control. The limits from the proposed procedure are compared to an existing or conventional method. Four examples are investigated: two of volumetric modulated arc therapy (VMAT) point dose quality assurance (QA) and two of routine linear accelerator output QA. The tolerance limits range from about 6% larger to 9% smaller than conventional action limits for VMAT QA cases. For the linac output QA, tolerance limits are about 60% smaller than conventional action limits. The operational procedure describe in this work is based on established quality management tools and will provide a systematic guide to set up tolerance and action limits for different equipment and processes. (paper)

  15. A method of setting limits for the purpose of quality assurance

    Science.gov (United States)

    Sanghangthum, Taweap; Suriyapee, Sivalee; Kim, Gwe-Ya; Pawlicki, Todd

    2013-10-01

    The result from any assurance measurement needs to be checked against some limits for acceptability. There are two types of limits; those that define clinical acceptability (action limits) and those that are meant to serve as a warning that the measurement is close to the action limits (tolerance limits). Currently, there is no standard procedure to set these limits. In this work, we propose an operational procedure to set tolerance limits and action limits. The approach to establish the limits is based on techniques of quality engineering using control charts and a process capability index. The method is different for tolerance limits and action limits with action limits being categorized into those that are specified and unspecified. The procedure is to first ensure process control using the I-MR control charts. Then, the tolerance limits are set equal to the control chart limits on the I chart. Action limits are determined using the Cpm process capability index with the requirements that the process must be in-control. The limits from the proposed procedure are compared to an existing or conventional method. Four examples are investigated: two of volumetric modulated arc therapy (VMAT) point dose quality assurance (QA) and two of routine linear accelerator output QA. The tolerance limits range from about 6% larger to 9% smaller than conventional action limits for VMAT QA cases. For the linac output QA, tolerance limits are about 60% smaller than conventional action limits. The operational procedure describe in this work is based on established quality management tools and will provide a systematic guide to set up tolerance and action limits for different equipment and processes.

  16. AOAC Official MethodSM Matrix Extension Validation Study of Assurance GDSTM for the Detection of Salmonella in Selected Spices.

    Science.gov (United States)

    Feldsine, Philip; Kaur, Mandeep; Shah, Khyati; Immerman, Amy; Jucker, Markus; Lienau, Andrew

    2015-01-01

    Assurance GDSTM for Salmonella Tq has been validated according to the AOAC INTERNATIONAL Methods Committee Guidelines for Validation of Microbiological Methods for Food and Environmental Surfaces for the detection of selected foods and environmental surfaces (Official Method of AnalysisSM 2009.03, Performance Tested MethodSM No. 050602). The method also completed AFNOR validation (following the ISO 16140 standard) compared to the reference method EN ISO 6579. For AFNOR, GDS was given a scope covering all human food, animal feed stuff, and environmental surfaces (Certificate No. TRA02/12-01/09). Results showed that Assurance GDS for Salmonella (GDS) has high sensitivity and is equivalent to the reference culture methods for the detection of motile and non-motile Salmonella. As part of the aforementioned validations, inclusivity and exclusivity studies, stability, and ruggedness studies were also conducted. Assurance GDS has 100% inclusivity and exclusivity among the 100 Salmonella serovars and 35 non-Salmonella organisms analyzed. To add to the scope of the Assurance GDS for Salmonella method, a matrix extension study was conducted, following the AOAC guidelines, to validate the application of the method for selected spices, specifically curry powder, cumin powder, and chili powder, for the detection of Salmonella. PMID:26268975

  17. DNBR limit calculation by sampling statistical method

    International Nuclear Information System (INIS)

    The parametric uncertainties of DNBR and exit quality were calculated using sampling statistical method based on Wilks formula and VIPRE-W code. Then the DNBR design limit and exit quality limit were got by combining with the uncertainties of models and DNB correlation. This method can gain the more DNBR margin than RTDP methodology which is developed by Westinghouse by comparison of these two methods. (authors)

  18. Adaptive Stochastic Methods for Sampling Driven Systems

    OpenAIRE

    Jones, Andrew; Leimkuhler, Benedict

    2011-01-01

    Thermostatting methods are discussed in the context of canonical sampling in the presence of driving stochastic forces. Generalisations of the Nosé-Hoover method and Langevin dynamics are introduced which are able to dissipate excess heat introduced by steady Brownian perturbation (without a priori knowledge of its strength) while preserving ergodicity. Implementation and parameter selection are considered. It is demonstrated using numerical experiments that the methods derived can adaptively...

  19. Survey on Positioning System: Sampling methods

    OpenAIRE

    Jiang, Sheng; Trinkle, Matthew; Wang, Hongyuan

    2013-01-01

    Millimeter-accuracy Ultra-Wideband (UWB) positioning systems using the Time Difference Of Arrival (TDOA) algorithm are able to be utilized in military and many other important applications. Previous research on UWB positioning system has achieved up to mm or sub-mm accuracy. However, one bottleneck in UWB system is at sampling high resolution UWB signals, as well as high resolution timing information. In this paper, UWB positioning systems are surveyed and we focus on sampling methods for han...

  20. Sampling Procedures for Coordinating Stratified Samples : Methods Based on Microstrata

    OpenAIRE

    Nedyalkova, Desislava; Tillé, Yves; Pea, Johan

    2016-01-01

    The aim of sampling coordination is to maximize or minimize the overlap between several samples drawn successively in a population that changes over time. Therefore, the selection of a new sample will depend on the samples previously drawn. In order to obtain a larger (or smaller) overlap of the samples than the one obtained by independent selection of samples, a dependence between the samplesmust be introduced. This dependence will emphasize (or limit) the number of common units in the selec...

  1. Assessing Local Risk of Rifampicin-Resistant Tuberculosis in KwaZulu-Natal, South Africa Using Lot Quality Assurance Sampling.

    Directory of Open Access Journals (Sweden)

    Christine L Heidebrecht

    Full Text Available KwaZulu-Natal (KZN has the highest burden of notified multidrug-resistant tuberculosis (MDR TB and extensively drug-resistant (XDR TB cases in South Africa. A better understanding of spatial heterogeneity in the risk of drug-resistance may help to prioritize local responses.Between July 2012 and June 2013, we conducted a two-way Lot Quality Assurance Sampling (LQAS study to classify the burden of rifampicin (RIF-resistant TB among incident TB cases notified within the catchment areas of seven laboratories in two northern and one southern district of KZN. Decision rules for classification of areas as having either a high- or low-risk of RIF resistant TB (based on proportion of RIF resistance among all TB cases were based on consultation with local policy makers.We classified five areas as high-risk and two as low-risk. High-risk areas were identified in both Southern and Northern districts, with the greatest proportion of RIF resistance observed in the northernmost area, the Manguzi community situated on the Mozambique border.Our study revealed heterogeneity in the risk of RIF resistant disease among incident TB cases in KZN. This study demonstrates the potential for LQAS to detect geographic heterogeneity in areas where access to drug susceptibility testing is limited.

  2. Monitoring maternal, newborn, and child health interventions using lot quality assurance sampling in Sokoto State of northern Nigeria

    Science.gov (United States)

    Abegunde, Dele; Orobaton, Nosa; Shoretire, Kamil; Ibrahim, Mohammed; Mohammed, Zainab; Abdulazeez, Jumare; Gwamzhi, Ringpon; Ganiyu, Akeem

    2015-01-01

    Background Maternal mortality ratio and infant mortality rate are as high as 1,576 per 100,000 live births and 78 per 1,000 live births, respectively, in Nigeria's northwestern region, where Sokoto State is located. Using applicable monitoring indicators for tracking progress in the UN/WHO framework on continuum of maternal, newborn, and child health care, this study evaluated the progress of Sokoto toward achieving the Millennium Development Goals (MDGs) 4 and 5 by December 2015. The changes in outcomes in 2012–2013 associated with maternal and child health interventions were assessed. Design We used baseline and follow-up lot quality assurance sampling (LQAS) data obtained in 2012 and 2013, respectively. In each of the surveys, data were obtained from 437 households sampled from 19 LQAS locations in each of the 23 local government areas (LGAs). The composite state-level coverage estimates of the respective indicators were aggregated from estimated LGA coverage estimates. Results None of the nine indicators associated with the continuum of maternal, neonatal, and child care satisfied the recommended 90% coverage target for achieving MDGs 4 and 5. Similarly, the average state coverage estimates were lower than national coverage estimates. Marginal improvements in coverage were obtained in the demand for family planning satisfied, antenatal care visits, postnatal care for mothers, and exclusive breast-feeding. Antibiotic treatment for acute pneumonia increased significantly by 12.8 percentage points. The majority of the LGAs were classifiable as low-performing, high-priority areas for intensified program intervention. Conclusions Despite the limited time left in the countdown to December 2015, Sokoto State, Nigeria, is not on track to achieving the MDG 90% coverage of indicators tied to the continuum of maternal and child care, to reduce maternal and childhood mortality by a third by 2015. Targeted health system investments at the primary care level remain a

  3. Bayesian individualization via sampling-based methods.

    Science.gov (United States)

    Wakefield, J

    1996-02-01

    We consider the situation where we wish to adjust the dosage regimen of a patient based on (in general) sparse concentration measurements taken on-line. A Bayesian decision theory approach is taken which requires the specification of an appropriate prior distribution and loss function. A simple method for obtaining samples from the posterior distribution of the pharmacokinetic parameters of the patient is described. In general, these samples are used to obtain a Monte Carlo estimate of the expected loss which is then minimized with respect to the dosage regimen. Some special cases which yield analytic solutions are described. When the prior distribution is based on a population analysis then a method of accounting for the uncertainty in the population parameters is described. Two simulation studies showing how the methods work in practice are presented. PMID:8827585

  4. Are patent medicine vendors effective agents in malaria control? Using lot quality assurance sampling to assess quality of practice in Jigawa, Nigeria.

    Directory of Open Access Journals (Sweden)

    Sima Berendes

    Full Text Available BACKGROUND: Patent medicine vendors (PMV provide antimalarial treatment and care throughout Sub-Saharan Africa, and can play an important role in the fight against malaria. Their close-to-client infrastructure could enable lifesaving artemisinin-based combination therapy (ACT to reach patients in time. However, systematic assessments of drug sellers' performance quality are crucial if their role is to be managed within the health system. Lot quality assurance sampling (LQAS could be an efficient method to monitor and evaluate PMV practice, but has so far never been used for this purpose. METHODS: In support of the Nigeria Malaria Booster Program we assessed PMV practices in three Senatorial Districts (SDs of Jigawa, Nigeria. A two-stage LQAS assessed whether at least 80% of PMV stores in SDs used national treatment guidelines. Acceptable sampling errors were set in consultation with government officials (alpha and beta <0.10. The hypergeometric formula determined sample sizes and cut-off values for SDs. A structured assessment tool identified high and low performing SDs for quality of care indicators. FINDINGS: Drug vendors performed poorly in all SDs of Jigawa for all indicators. For example, all SDs failed for stocking and selling first-line antimalarials. PMV sold no longer recommended antimalarials, such as Chloroquine, Sulfadoxine-Pyrimethamine and oral Artesunate monotherapy. Most PMV were ignorant of and lacked training about new treatment guidelines that had endorsed ACTs as first-line treatment for uncomplicated malaria. CONCLUSION: There is urgent need to regularly monitor and improve the availability and quality of malaria treatment provided by medicine sellers in Nigeria; the irrational use of antimalarials in the ACT era revealed in this study bears a high risk of economic loss, death and development of drug resistance. LQAS has been shown to be a suitable method for monitoring malaria-related indicators among PMV, and should be

  5. 21 CFR 800.20 - Patient examination gloves and surgeons' gloves; sample plans and test method for leakage defects...

    Science.gov (United States)

    2010-04-01

    ...; sample plans and test method for leakage defects; adulteration. 800.20 Section 800.20 Food and Drugs FOOD... plans and test method for leakage defects; adulteration. (a) Purpose. The prevalence of human... adulteration for patient examination and surgeons' gloves as a means of assuring safe and effective devices....

  6. Method for measuring low activity extensive samples

    International Nuclear Information System (INIS)

    This paper discusses a method of measuring low intensity gamma radiation from extensive sources using solid state detectors. In the first part the variation of the detector efficiency for a point source as a function of source position is measured. It is seen that the angular dependence is particularly important. With this response function known, a semi empirical model is developed for the computation of the efficiency in cases of extensive radiation fields. Measurements are carried out which show the adequacy of the model. The method is suitable for liquid samples such as drinkable water, industrial waste liquids and sewage liquids. It is therefore useful for water quality monitoring and pollution control. ((orig.))

  7. Countdown to 2015: Tracking Maternal and Child Health Intervention Targets Using Lot Quality Assurance Sampling in Bauchi State Nigeria.

    Directory of Open Access Journals (Sweden)

    Dele Abegunde

    Full Text Available Improving maternal and child health remains a top priority in Nigeria's Bauchi State in the northeastern region where the maternal mortality ratio (MMR and infant mortality rate (IMR are as high as 1540 per 100,000 live births and 78 per 1,000 live births respectively. In this study, we used the framework of the continuum of maternal and child care to evaluate the impact of interventions in Bauchi State focused on improved maternal and child health, and to ascertain progress towards the achievement of Millennium Development Goals (MDGs 4 and 5.At baseline (2012 and then at follow-up (2013, we randomly sampled 340 households from 19 random locations in each of the 20 Local Government Areas (LGA of Bauchi State in Northern Nigeria, using the Lot Quality Assurance Sampling (LQAS technique. Women residents in the households were interviewed about their own health and that of their children. Estimated LGA coverage of maternal and child health indicators were aggregated across the State. These values were then compared to the national figures, and the differences from 2012 to 2014 were calculated.For several of the indicators, a modest improvement from baseline was found. However, the indicators in the continuum of care neither reached the national average nor attained the 90% globally recommended coverage level. The majority of the LGA surveyed were classifiable as high priority, thus requiring intensified efforts and programmatic scale up.Intensive scale-up of programs and interventions is needed in Bauchi State, Northern Nigeria, to accelerate, consolidate and sustain the modest but significant achievements in the continuum of care, if MDGs 4 and 5 are to be achieved by the end of 2015. The intentional focus of LGAs as the unit of intervention ought to be considered a condition precedent for future investments. Priority should be given to the re-allocating resources to program areas and regions where coverage has been low. Finally, systematic

  8. Comparisons of methods for generating conditional Poisson samples and Sampford samples

    OpenAIRE

    Grafström, Anton

    2005-01-01

    Methods for conditional Poisson sampling (CP-sampling) and Sampford sampling are compared and the focus is on the efficiency of the methods. The efficiency is investigated by simulation in different sampling situations. It was of interest to compare methods since new methods for both CP-sampling and Sampford sampling were introduced by Bondesson, Traat & Lundqvist in 2004. The new methods are acceptance rejection methods that use the efficient Pareto sampling method. They are found to be ...

  9. A DOE manual: DOE Methods for Evaluating Environmental and Waste Management Samples

    Energy Technology Data Exchange (ETDEWEB)

    Goheen, S.C.; McCulloch, M.; Riley, R.G. [and others

    1994-03-01

    Waste Management inherently requires knowledge of the waste`s chemical composition. The waste can often be analyzed by established methods; however, if the samples are radioactive, or are plagued by other complications, established methods may not be feasible. The US Department of Energy (DOE) has been faced with managing some waste types that are not amenable to standard or available methods, so new or modified sampling and analysis methods are required. These methods are incorporated into DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods), which is a guidance/methods document for sampling and analysis activities in support of DOE sites. It is a document generated by consensus of the DOE laboratory staff and is intended to fill the gap within existing guidance documents (e. g., the Environmental Protection Agency`s (EPA`s) Test Methods for Evaluating Solid Waste, SW-846), which apply to low-level or non-radioactive samples. DOE Methods fills the gap by including methods that take into account the complexities of DOE site matrices. The most recent update, distributed in October 1993, contained quality assurance (QA), quality control (QC), safety, sampling, organic analysis, inorganic analysis, and radioanalytical guidance as well as 29 methods. The next update, which will be distributed in April 1994, will contain 40 methods and will therefore have greater applicability. All new methods are either peer reviewed or labeled ``draft`` methods. Draft methods were added to speed the release of methods to field personnel.

  10. A DOE manual: DOE Methods for Evaluating Environmental and Waste Management Samples

    International Nuclear Information System (INIS)

    Waste Management inherently requires knowledge of the waste's chemical composition. The waste can often be analyzed by established methods; however, if the samples are radioactive, or are plagued by other complications, established methods may not be feasible. The US Department of Energy (DOE) has been faced with managing some waste types that are not amenable to standard or available methods, so new or modified sampling and analysis methods are required. These methods are incorporated into DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods), which is a guidance/methods document for sampling and analysis activities in support of DOE sites. It is a document generated by consensus of the DOE laboratory staff and is intended to fill the gap within existing guidance documents (e. g., the Environmental Protection Agency's (EPA's) Test Methods for Evaluating Solid Waste, SW-846), which apply to low-level or non-radioactive samples. DOE Methods fills the gap by including methods that take into account the complexities of DOE site matrices. The most recent update, distributed in October 1993, contained quality assurance (QA), quality control (QC), safety, sampling, organic analysis, inorganic analysis, and radioanalytical guidance as well as 29 methods. The next update, which will be distributed in April 1994, will contain 40 methods and will therefore have greater applicability. All new methods are either peer reviewed or labeled ''draft'' methods. Draft methods were added to speed the release of methods to field personnel

  11. Are Patent Medicine Vendors Effective Agents in Malaria Control? Using Lot Quality Assurance Sampling to Assess Quality of Practice in Jigawa, Nigeria

    OpenAIRE

    Sima Berendes; Olusegun Adeyemi; Edward Adekola Oladele; Olusola Bukola Oresanya; Festus Okoh; Joseph J Valadez

    2012-01-01

    BACKGROUND: Patent medicine vendors (PMV) provide antimalarial treatment and care throughout Sub-Saharan Africa, and can play an important role in the fight against malaria. Their close-to-client infrastructure could enable lifesaving artemisinin-based combination therapy (ACT) to reach patients in time. However, systematic assessments of drug sellers' performance quality are crucial if their role is to be managed within the health system. Lot quality assurance sampling (LQAS) could be an eff...

  12. A Quality Assurance Method that Utilizes 3D Dosimetry and Facilitates Clinical Interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Oldham, Mark, E-mail: mark.oldham@duke.edu [Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Thomas, Andrew; O' Daniel, Jennifer; Juang, Titania [Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Ibbott, Geoffrey [University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Adamovics, John [Rider University, Lawrenceville, New Jersey (United States); Kirkpatrick, John P. [Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

    2012-10-01

    Purpose: To demonstrate a new three-dimensional (3D) quality assurance (QA) method that provides comprehensive dosimetry verification and facilitates evaluation of the clinical significance of QA data acquired in a phantom. Also to apply the method to investigate the dosimetric efficacy of base-of-skull (BOS) intensity-modulated radiotherapy (IMRT) treatment. Methods and Materials: Two types of IMRT QA verification plans were created for 6 patients who received BOS IMRT. The first plan enabled conventional 2D planar IMRT QA using the Varian portal dosimetry system. The second plan enabled 3D verification using an anthropomorphic head phantom. In the latter, the 3D dose distribution was measured using the DLOS/Presage dosimetry system (DLOS = Duke Large-field-of-view Optical-CT System, Presage Heuris Pharma, Skillman, NJ), which yielded isotropic 2-mm data throughout the treated volume. In a novel step, measured 3D dose distributions were transformed back to the patient's CT to enable calculation of dose-volume histograms (DVH) and dose overlays. Measured and planned patient DVHs were compared to investigate clinical significance. Results: Close agreement between measured and calculated dose distributions was observed for all 6 cases. For gamma criteria of 3%, 2 mm, the mean passing rate for portal dosimetry was 96.8% (range, 92.0%-98.9%), compared to 94.9% (range, 90.1%-98.9%) for 3D. There was no clear correlation between 2D and 3D passing rates. Planned and measured dose distributions were evaluated on the patient's anatomy, using DVH and dose overlays. Minor deviations were detected, and the clinical significance of these are presented and discussed. Conclusions: Two advantages accrue to the methods presented here. First, treatment accuracy is evaluated throughout the whole treated volume, yielding comprehensive verification. Second, the clinical significance of any deviations can be assessed through the generation of DVH curves and dose overlays on

  13. A Quality Assurance Method that Utilizes 3D Dosimetry and Facilitates Clinical Interpretation

    International Nuclear Information System (INIS)

    Purpose: To demonstrate a new three-dimensional (3D) quality assurance (QA) method that provides comprehensive dosimetry verification and facilitates evaluation of the clinical significance of QA data acquired in a phantom. Also to apply the method to investigate the dosimetric efficacy of base-of-skull (BOS) intensity-modulated radiotherapy (IMRT) treatment. Methods and Materials: Two types of IMRT QA verification plans were created for 6 patients who received BOS IMRT. The first plan enabled conventional 2D planar IMRT QA using the Varian portal dosimetry system. The second plan enabled 3D verification using an anthropomorphic head phantom. In the latter, the 3D dose distribution was measured using the DLOS/Presage dosimetry system (DLOS = Duke Large-field-of-view Optical-CT System, Presage Heuris Pharma, Skillman, NJ), which yielded isotropic 2-mm data throughout the treated volume. In a novel step, measured 3D dose distributions were transformed back to the patient’s CT to enable calculation of dose–volume histograms (DVH) and dose overlays. Measured and planned patient DVHs were compared to investigate clinical significance. Results: Close agreement between measured and calculated dose distributions was observed for all 6 cases. For gamma criteria of 3%, 2 mm, the mean passing rate for portal dosimetry was 96.8% (range, 92.0%–98.9%), compared to 94.9% (range, 90.1%–98.9%) for 3D. There was no clear correlation between 2D and 3D passing rates. Planned and measured dose distributions were evaluated on the patient’s anatomy, using DVH and dose overlays. Minor deviations were detected, and the clinical significance of these are presented and discussed. Conclusions: Two advantages accrue to the methods presented here. First, treatment accuracy is evaluated throughout the whole treated volume, yielding comprehensive verification. Second, the clinical significance of any deviations can be assessed through the generation of DVH curves and dose overlays on

  14. 76 FR 26341 - Medicaid Program; Methods for Assuring Access to Covered Medicaid Services

    Science.gov (United States)

    2011-05-06

    ... payments are consistent with efficiency, economy, and quality of care and are sufficient to enlist enough... assure that payments are consistent with efficiency, economy, and quality of care and are sufficient to.... We are soliciting comments on this basic approach. It is important to note that, if adopted,...

  15. Programs and analytical methods for the U.S. Geological Survey acid-rain quality-assurance project. Water Resources Investigation

    International Nuclear Information System (INIS)

    The U.S. Geological Survey operates four programs to provide external quality-assurance of wet deposition monitoring by the National Atmospheric Deposition Program and the National Trends Network. An intersite-comparison program assesses the precision and bias of onsite determinations of pH and specific conductance made by site operators. A blind-audit program is used to assess the effect of routine sample-handling procedures and transportation on the precision and bias of wet-deposition data. An interlaboratory-comparison program is used to assess analytical results from three or more laboratories, which routinely analyze wet-deposition samples from the major North American networks, to determine if comparability exists between laboratory analytical results and to provide estimates of the analytical precision of each laboratory. A collocated-sampler program is used to estimate the precision of wet/dry precipitation sampling throughout the National Atmospheric Deposition Program and the National Trends Network, to assess the variability of diverse spatial arrays, and to evaluate the impact of violations of specific site criteria. The report documents the procedures and analytical methods used in these four quality-assurance programs

  16. 40 CFR Appendix I to Part 261 - Representative Sampling Methods

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Representative Sampling Methods I...—Representative Sampling Methods The methods and equipment used for sampling waste materials will vary with the form and consistency of the waste materials to be sampled. Samples collected using the...

  17. Tracking the quality of care for sick children using lot quality assurance sampling: targeting improvements of health services in Jigawa, Nigeria.

    Directory of Open Access Journals (Sweden)

    Edward Adekola Oladele

    Full Text Available BACKGROUND: In Nigeria, 30% of child deaths are due to malaria. The National Malaria Control Program of Nigeria (NMCP during 2009 initiated a program to improve the quality of paediatric malaria services delivered in health facilities (HF. This study reports a rapid approach used to assess the existing quality of services in Jigawa state at decentralised levels of the health system. METHODS: NMCP selected Lot Quality Assurance Sampling (LQAS to identify the variation in HF service quality among Senatorial Districts (SD. LQAS was selected because it was affordable and could be used by local health workers (HW in a population-based survey. NMCP applied a 2-stage LQAS using a structured Rapid Health Facility Assessment (R-HFA tool to identify high and low performing SD for specified indicators. FINDINGS: LQAS identified variations in HF performance (n = 21 and enabled resources to be targeted to address priorities. All SD exhibited deficient essential services, supplies and equipment. Only 9.7% of HF had Artemisinin-based Combination Therapies and other first-line treatments for childhood illnesses. No SD and few HF exhibited adequate HW performance for the assessment, treatment or counselling of sick children. Using the IMCI algorithm, 17.5% of HW assessed the child's vaccination status, 46.8% assessed nutritional status, and 65.1% assessed children for dehydration. Only 5.1% of HW treatments were appropriate for the assessment. Exit interviews revealed that 5.1% of caregivers knew their children's illness, and only 19.9% could accurately describe how to administer the prescribed drug. CONCLUSION: This R-HFA, using LQAS principles, is a rapid, simple tool for assessing malaria services and can be used at scale. It identified technical deficiencies that could be corrected by improved continuing medical education, targeted supervision, and recurrent R-HFA assessments of the quality of services.

  18. Selected quality assurance data for water samples collected by the U.S. Geological Survey, Idaho National Engineering Laboratory, Idaho, 1980 to 1988

    International Nuclear Information System (INIS)

    Multiple water samples from 115 wells and 3 surface water sites were collected between 1980 and 1988 for the ongoing quality assurance program at the Idaho National Engineering Laboratory. The reported results from the six laboratories involved were analyzed for agreement using descriptive statistics. The constituents and properties included: tritium, plutonium-238, plutonium-239, -240 (undivided), strontium-90, and americium-241, cesium-137, total dissolved chromium, selected dissolved trace metals, sodium, chloride, nitrate, selected purgeable organic compounds, and specific conductance. Agreement could not be calculated for purgeable organic compounds, trace metals, some nitrates and blank sample analyses because analytical uncertainties were not consistently reported. However, differences between results for most of these data were calculated. The blank samples were not analyzed for differences. The laboratory results analyzed using descriptive statistics showed a median agreement between all useable data pairs of 95%. 13 refs., 4 figs., 24 tabs

  19. Selected quality assurance data for water samples collected by the US Geological Survey, Idaho National Engineering Laboratory, Idaho, 1980 to 1988

    International Nuclear Information System (INIS)

    Multiple water samples from 115 wells and 3 surface-water sites were collected between 1980 and 1988 for the ongoing quality assurance program at the Idaho National Engineering Laboratory. The reported results from the six laboratories involved were analyzed for agreement using descriptive statistics. The analytical constituents and properties included: tritium, plutonium-238, plutonium-239, -240 (undivided), strontium-90, americium-241, cesium-137, total dissolved chromium, selected dissolved trace metals, sodium, chloride, nitrate, selected purgeable organic compounds, and specific conductance. Agreement could not be calculated for trace metals, some nitrates, purgeable organic compounds, and blank-sample analyses because analytical uncertainties were not consistently reported. However, differences between results for most of these data were calculated. The blank samples were not analyzed for difference. The laboratory results analyzed using descriptive statistics showed a median agreement of 95 percent between all useable data pairs. 13 refs., 4 figs., 24 tabs

  20. Methods, quality assurance, and data for assessing atmospheric deposition of pesticides in the Central Valley of California

    Science.gov (United States)

    Zamora, Celia; Majewski, Michael S.; Foreman, William T.

    2013-01-01

    The U.S. Geological Survey monitored atmospheric deposition of pesticides in the Central Valley of California during two studies in 2001 and 2002–04. The 2001 study sampled wet deposition (rain) and storm-drain runoff in the Modesto, California, area during the orchard dormant-spray season to examine the contribution of pesticide concentrations to storm runoff from rainfall. In the 2002–04 study, the number and extent of collection sites in the Central Valley were increased to determine the areal distribution of organophosphate insecticides and other pesticides, and also five more sample types were collected. These were dry deposition, bulk deposition, and three sample types collected from a soil box: aqueous phase in runoff, suspended sediment in runoff, and surficial-soil samples. This report provides concentration data and describes methods and quality assurance of sample collection and laboratory analysis for pesticide compounds in all samples collected from 16 sites. Each sample was analyzed for 41 currently used pesticides and 23 pesticide degradates, including oxygen analogs (oxons) of 9 organophosphate insecticides. Analytical results are presented by sample type and study period. The median concentrations of both chloryprifos and diazinon sampled at four urban (0.067 micrograms per liter [μg/L] and 0.515 μg/L, respectively) and four agricultural sites (0.079 μg/L and 0.583 μg/L, respectively) during a January 2001 storm event in and around Modesto, Calif., were nearly identical, indicating that the overall atmospheric burden in the region appeared to be fairly similar during the sampling event. Comparisons of median concentrations in the rainfall to those in the McHenry storm-drain runoff showed that, for some compounds, rainfall contributed a substantial percentage of the concentration in the runoff; for other compounds, the concentrations in rainfall were much greater than in the runoff. For example, diazinon concentrations in rainfall were about

  1. CC-Case as an Integrated Method of Security Analysis and Assurance over Life-cycle Process

    Directory of Open Access Journals (Sweden)

    Tomoko Kaneko

    2015-05-01

    Full Text Available Secure system design faces many risks such as information leakage and denial of service. We propose a method named CC-Case to describe se-curity assurance cases based on the security struc-tures and thereat analysis. CC-Case uses Common Criteria (ISO/IEC15408. While the scope of CC-Case mainly focuses to the requirement stage, CC-Case can handle the life-cycle process of sys-tem design that contains the requirement, design, implementation, test and the maintenance stages. It can make countermeasure easily against the situation which an unexpected new threat produced by invisible attackers incessantly.

  2. Refinement strategies for stratified sampling methods

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Charles [Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, Livermore, CA 94551-0808 (United States)]. E-mail: chtong@llnl.gov

    2006-10-15

    In many computer experiments the adequacy of a given sample to give acceptable statistical estimates cannot be determined a priori, and thus the ability to extend or refine an experimental design may be important. This paper describes refinement strategies for the class of stratified experimental designs such as latin hypercubes, orthogonal arrays, and factorial designs. A few applications are given to demonstrate their usefulness.

  3. Conflict Prevention and Separation Assurance Method in the Small Aircraft Transportation System

    Science.gov (United States)

    Consiglio, Maria C.; Carreno, Victor A.; Williams, Daniel M.; Munoz, Cesar

    2005-01-01

    A multilayer approach to the prevention of conflicts due to the loss of aircraft-to-aircraft separation which relies on procedures and on-board automation was implemented as part of the SATS HVO Concept of Operations. The multilayer system gives pilots support and guidance during the execution of normal operations and advance warning for procedure deviations or off-nominal operations. This paper describes the major concept elements of this multilayer approach to separation assurance and conflict prevention and provides the rationale for its design. All the algorithms and functionality described in this paper have been implemented in an aircraft simulation in the NASA Langley Research Center s Air Traffic Operation Lab and on the NASA Cirrus SR22 research aircraft.

  4. 19 CFR 151.70 - Method of sampling by Customs.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Method of sampling by Customs. 151.70 Section 151.70 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF... Method of sampling by Customs. A general sample shall be taken from each sampling unit, unless it is...

  5. A method for sampling waste corn

    Science.gov (United States)

    Frederick, R.B.; Klaas, E.E.; Baldassarre, G.A.; Reinecke, K.J.

    1984-01-01

    Corn had become one of the most important wildlife food in the United States. It is eaten by a wide variety of animals, including white-tailed deer (Odocoileus virginianus ), raccoon (Procyon lotor ), ring-necked pheasant (Phasianus colchicus , wild turkey (Meleagris gallopavo ), and many species of aquatic birds. Damage to unharvested crops had been documented, but many birds and mammals eat waste grain after harvest and do not conflict with agriculture. A good method for measuring waste-corn availability can be essential to studies concerning food density and food and feeding habits of field-feeding wildlife. Previous methods were developed primarily for approximating losses due to harvest machinery. In this paper, a method is described for estimating the amount of waste corn potentially available to wildlife. Detection of temporal changes in food availability and differences caused by agricultural operations (e.g., recently harvested stubble fields vs. plowed fields) are discussed.

  6. Understanding Sampling Style Adversarial Search Methods

    CERN Document Server

    Ramanujan, Raghuram; Selman, Bart

    2012-01-01

    UCT has recently emerged as an exciting new adversarial reasoning technique based on cleverly balancing exploration and exploitation in a Monte-Carlo sampling setting. It has been particularly successful in the game of Go but the reasons for its success are not well understood and attempts to replicate its success in other domains such as Chess have failed. We provide an in-depth analysis of the potential of UCT in domain-independent settings, in cases where heuristic values are available, and the effect of enhancing random playouts to more informed playouts between two weak minimax players. To provide further insights, we develop synthetic game tree instances and discuss interesting properties of UCT, both empirically and analytically.

  7. Uncertainty quantification of neutronics characteristics using Latin hypercube sampling method

    International Nuclear Information System (INIS)

    The Latin Hypercube Sampling (LHS) method is applied to the uncertainty quantification of neutronics characteristics based on the Monte-Carlo based sampling method. The Monte-Carlo based sampling method is one of the uncertainty quantification methods of neutronics characteristics (e.g. neutron multiplication factor) due to uncertainty cross section. The sampling method has the advantage that burnup and thermal-hydraulics feedback effects are easily considered in complicated light water reactor core analysis. Contrary, the sampling method has the disadvantage that statistical errors are involved in estimated uncertainties of neutronics characteristics since the sampling method is a probabilistic approach. Although the statistical errors can be reduced by increasing the number of samples (e.g. number of perturbed cross section libraries), computational cost also increases. Therefore development of an efficient uncertainty quantification method, which provides smaller statistical error of estimated uncertainty while reducing number of samples, is highly desirable. In the present study, adequacy and performance of the LHS method is investigated as an efficient Monte-Carlo based sampling method. Uncertainty quantification of multiplication factor for a BWR fuel assembly is carried out with the LHS method. The results indicate that uncertainty quantification using the LHS method is more efficient than that using the conventional sampling method, which utilizes simple random sampling of cross sections. (author)

  8. Optimisation of small-scale hydropower using quality assurance methods - Preliminary project; Vorprojekt: Optimierung von Kleinwasserkraftwerken durch Qualitaetssicherung. Programm Kleinwasserkraftwerke

    Energy Technology Data Exchange (ETDEWEB)

    Hofer, S.; Staubli, T.

    2006-11-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) presents the results of a preliminary project that examined how quality assurance methods can be used in the optimisation of small-scale hydropower projects. The aim of the project, to use existing know-how, experience and synergies, is examined. Discrepancies in quality and their effects on production prices were determined in interviews. The paper describes best-practice guidelines for the quality assurance of small-scale hydro schemes. A flow chart describes the various steps that have to be taken in the project and realisation work. Information collected from planners and from interviews made with them are presented along with further information obtained from literature. The results of interviews concerning planning work, putting to tender and the construction stages of these hydro schemes are presented and commented on. Similarly, the operational phase of such power plant is also examined, including questions on operation and guarantees. The aims of the follow-up main project - the definition of a tool and guidelines for ensuring quality - are briefly reviewed.

  9. Transuranic Waste Characterization Quality Assurance Program Plan

    International Nuclear Information System (INIS)

    This quality assurance plan identifies the data necessary, and techniques designed to attain the required quality, to meet the specific data quality objectives associated with the DOE Waste Isolation Pilot Plant (WIPP). This report specifies sampling, waste testing, and analytical methods for transuranic wastes

  10. Validation of a 20-h real-time PCR method for screening of Salmonella in poultry faecal samples

    DEFF Research Database (Denmark)

    Löfström, Charlotta; Hansen, Flemming; Hoorfar, Jeffrey

    Efficient and rapid monitoring of Salmonella in the poultry production chain is necessary to assure safe food. The objective was to validate an open-formula real-time PCR method for screening of Salmonella in poultry faeces (sock samples). The method consists of incubation in buffered peptone water...... (NordVal). The comparative trial was performed against a reference method from the Nordic Committee on Food Analysis (NMKL187, 2007) using 132 artificially and naturally contaminated samples. The limit of detection (LOD50) was found to be 24 and 33 CFU/sample for the PCR and NMKL187 methods....... Apart from one of the samples that was artificially contaminated with 1-10 CFU/sample being a false-negative with PCR for one of the laboratories, no false-positive or false-negative results were reported. This test supplies the growing demand for validated diagnostic PCR methods for screening of...

  11. A Refined Experience Sampling Method to Capture Mobile User Experience

    OpenAIRE

    Cherubini, Mauro; Oliver, Nuria

    2009-01-01

    This paper reviews research methods used to understand the user experience of mobile technology. The paper presents an improvement of the Experience Sampling Method and case studies supporting its design. The paper concludes with an agenda of future work for improving research in this field. Keywords: Research methods, topology, case study, contrasting graph, Experience Sampling Method

  12. A Comparison of EPI Sampling, Probability Sampling, and Compact Segment Sampling Methods for Micro and Small Enterprises

    OpenAIRE

    CHAO, LI-WEI; Szrek, Helena; Peltzer, Karl; Ramlagan, Shandir; Fleming, Peter; Leite, Rui; Magerman, Jesswill; Ngwenya, Godfrey B.; Pereira, Nuno Sousa; Behrman, Jere

    2011-01-01

    Finding an efficient method for sampling micro- and small-enterprises (MSEs) for research and statistical reporting purposes is a challenge in developing countries, where registries of MSEs are often nonexistent or outdated. This lack of a sampling frame creates an obstacle in finding a representative sample of MSEs. This study uses computer simulations to draw samples from a census of businesses and non-businesses in the Tshwane Municipality of South Africa, using three different sampling me...

  13. Sampling Methods for Wallenius' and Fisher's Noncentral Hypergeometric Distributions

    DEFF Research Database (Denmark)

    Fog, Agner

    2008-01-01

    mode, ratio-of-uniforms rejection method, and rejection by sampling in the tau domain. Methods for the multivariate distributions include: simulation of urn experiments, conditional method, Gibbs sampling, and Metropolis-Hastings sampling. These methods are useful for Monte Carlo simulation of models......Several methods for generating variates with univariate and multivariate Wallenius' and Fisher's noncentral hypergeometric distributions are developed. Methods for the univariate distributions include: simulation of urn experiments, inversion by binary search, inversion by chop-down search from the...... of biased sampling and models of evolution and for calculating moments and quantiles of the distributions....

  14. Generating a synthetic population of individuals in households: Sample-free vs sample-based methods

    OpenAIRE

    Lenormand, M.; Deffuant, G.

    2013-01-01

    We compare a sample-free method proposed by Gargiulo et al. (2010) and a sample-based method proposed by Ye et al. (2009) for generating a synthetic population, organised in households, from various statistics. We generate a reference population for a French region including 1310 municipalities and measure how both methods approximate it from a set of statistics derived from this reference population. We also perform a sensitivity analysis. The sample-free method better fits the reference dis...

  15. 19 CFR 151.83 - Method of sampling.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Method of sampling. 151.83 Section 151.83 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE Cotton § 151.83 Method of sampling. For determining the staple length of any lot...

  16. 7 CFR 29.110 - Method of sampling.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Method of sampling. 29.110 Section 29.110 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Inspectors, Samplers, and Weighers § 29.110 Method of sampling. In sampling...

  17. Quality Assurance Through Reimbursement

    OpenAIRE

    Shaughnessy, Peter W.; Kurowski, Bettina

    1982-01-01

    Quality assurance and reimbursement programs normally function separately in the health care field. This paper reviews objectives and certain conceptual issues associated with each type of program. Its primary intent is to summarize substantive and operational topics which must be addressed if quality of care is to be enhanced through reimbursement. The focus is on methods for integrating quality assurance and reimbursement. The final section presents topics for future research.

  18. Quality assurance exercise for estimating radiochemical recovery and low-levels of alpha emitters in urine samples: performance of Health Physics Laboratory, Tarapur

    International Nuclear Information System (INIS)

    As a part of quality assurance, Health Physics Laboratory took part in National inter-comparison exercise organized by Internal Dosimetry Section (IDS), BARC, Trombay for estimating radiochemical recovery of 232U, 242Pu and low-levels of alpha emitter such as 239Pu, 238U and 234U in five urine samples coded D1, D2, D3, D4 and D5. In this paper, performance of Health Physics Laboratory in the inter-comparison exercise is presented. The results submitted by Health Physics laboratory were found to be in good agreement with the organizer's (spiked) values. Nearly 6 laboratories from India participated in this inter-comparison exercise. The samples received, sample pre-concentration, radiochemical separation and alpha activity quantification procedure followed and the results obtained were reported to Head, IDS, BARC, Trombay within stipulated time. The radiochemical analysis of U-isotopes and Pu-isotopes in bioassay samples has been carried out by standardized analytical procedures

  19. Methods for collecting algal samples as part of the National Water-Quality Assessment Program

    Science.gov (United States)

    Porter, Stephen D.; Cuffney, Thomas F.; Gurtz, Martin E.; Meador, Michael R.

    1993-01-01

    Benthic algae (periphyton) and phytoplankton communities are characterized in the U.S. Geological Survey's National Water-Quality Assessment Program as part of an integrated physical, chemical, and biological assessment of the Nation's water quality. This multidisciplinary approach provides multiple lines of evidence for evaluating water-quality status and trends, and for refining an understanding of the factors that affect water-quality conditions locally, regionally, and nationally. Water quality can be characterized by evaluating the results of qualitative and quantitative measurements of the algal community. Qualitative periphyton samples are collected to develop of list of taxa present in the sampling reach. Quantitative periphyton samples are collected to measure algal community structure within selected habitats. These samples of benthic algal communities are collected from natural substrates, using the sampling methods that are most appropriate for the habitat conditions. Phytoplankton samples may be collected in large nonwadeable streams and rivers to meet specific program objectives. Estimates of algal biomass (chlorophyll content and ash-free dry mass) also are optional measures that may be useful for interpreting water-quality conditions. A nationally consistent approach provides guidance on site, reach, and habitat selection, as well as information on methods and equipment for qualitative and quantitative sampling. Appropriate quality-assurance and quality-control guidelines are used to maximize the ability to analyze data locally, regionally, and nationally.

  20. Method Description, Quality Assurance, Environmental Data, and other Information for Analysis of Pharmaceuticals in Wastewater-Treatment-Plant Effluents, Streamwater, and Reservoirs, 2004-2009

    Science.gov (United States)

    Phillips, Patrick J.; Smith, Steven G.; Kolpin, Dana W.; Zaugg, Steven D.; Buxton, Herbert T.; Furlong, Edward T.

    2010-01-01

    Abstract Wastewater-treatment-plant (WWTP) effluents are a demonstrated source of pharmaceuticals to the environment. During 2004-09, a study was conducted to identify pharmaceutical compounds in effluents from WWTPs (including two that receive substantial discharges from pharmaceutical formulation facilities), streamwater, and reservoirs. The methods used to determine and quantify concentrations of seven pharmaceuticals are described. In addition, the report includes information on pharmaceuticals formulated or potentially formulated at the two pharmaceutical formulation facilities that provide substantial discharge to two of the WWTPs, and potential limitations to these data are discussed. The analytical methods used to provide data on the seven pharmaceuticals (including opioids, muscle relaxants, and other pharmaceuticals) in filtered water samples also are described. Data are provided on method performance, including spike data, method detection limit results, and an estimation of precision. Quality-assurance data for sample collection and handling are included. Quantitative data are presented for the seven pharmaceuticals in water samples collected at WWTP discharge points, from streams, and at reservoirs. Occurrence data also are provided for 19 pharmaceuticals that were qualitatively identified. Flow data at selected WWTP and streams are presented. Between 2004-09, 35-38 effluent samples were collected from each of three WWTPs in New York and analyzed for seven pharmaceuticals. Two WWTPs (NY2 and NY3) receive substantial inflows (greater than 20 percent of plant flow) from pharmaceutical formulation facilities (PFF) and one (NY1) receives no PFF flow. Samples of effluents from 23 WWTPs across the United States were analyzed once for these pharmaceuticals as part of a national survey. Maximum pharmaceutical effluent concentrations for the national survey and NY1 effluent samples were generally less than 1 ug/L. Four pharmaceuticals (methadone, oxycodone

  1. On Angular Sampling Methods for 3-D Spatial Channel Models

    DEFF Research Database (Denmark)

    Fan, Wei; Jämsä, Tommi; Nielsen, Jesper Ødum; Pedersen, Gert Frølund

    2015-01-01

    This paper discusses generating three dimensional (3D) spatial channel models with emphasis on the angular sampling methods. Three angular sampling methods, i.e. modified uniform power sampling, modified uniform angular sampling, and random pairing methods are proposed and investigated in detail....... The random pairing method, which uses only twenty sinusoids in the ray-based model for generating the channels, presents good results if the spatial channel cluster is with a small elevation angle spread. For spatial clusters with large elevation angle spreads, however, the random pairing method would...

  2. Time efficient methods for scanning a fluorescent membrane with a fluorescent microscopic imager for the quality assurance of food

    Science.gov (United States)

    Lerm, Steffen; Holder, Silvio; Schellhorn, Mathias; Brückner, Peter; Linß, Gerhard

    2013-05-01

    An important part of the quality assurance of meat is the estimation of germs in the meat exudes. The kind and the number of the germs in the meat affect the medical risk for the consumer of the meat. State-of-the-art analyses of meat are incubator test procedures. The main disadvantages of such incubator tests are the time consumption, the necessary equipment and the need of special skilled employees. These facts cause in high inspection cost. For this reason a new method for the quality assurance is necessary which combines low detection limits and less time consumption. One approach for such a new method is fluorescence microscopic imaging. The germs in the meat exude are caught in special membranes by body-antibody reactions. The germ typical signature could be enhanced with fluorescent chemical markers instead of reproduction of the germs. Each fluorescent marker connects with a free germ or run off the membrane. An image processing system is used to detect the number of fluorescent particles. Each fluorescent spot should be a marker which is connected with a germ. Caused by the small object sizes of germs, the image processing system needs a high optical magnification of the camera. However, this leads to a small field of view and a small depth of focus. For this reasons the whole area of the membrane has to be scanned in three dimensions. To minimize the time consumption, the optimal path has to be found. This optimization problem is influenced by features of the hardware and is presented in this paper. The traversing range in each direction, the step width, the velocity, the shape of the inspection volume and the field of view have influence on the optimal path to scan the membrane.

  3. New adaptive sampling method in particle image velocimetry

    International Nuclear Information System (INIS)

    This study proposes a new adaptive method to enable the number of interrogation windows and their positions in a particle image velocimetry (PIV) image interrogation algorithm to become self-adapted according to the seeding density. The proposed method can relax the constraint of uniform sampling rate and uniform window size commonly adopted in the traditional PIV algorithm. In addition, the positions of the sampling points are redistributed on the basis of the spring force generated by the sampling points. The advantages include control of the number of interrogation windows according to the local seeding density and smoother distribution of sampling points. The reliability of the adaptive sampling method is illustrated by processing synthetic and experimental images. The synthetic example attests to the advantages of the sampling method. Compared with that of the uniform interrogation technique in the experimental application, the spatial resolution is locally enhanced when using the proposed sampling method. (technical design note)

  4. Financial assurances

    International Nuclear Information System (INIS)

    US Ecology is a full service waste management company. The company operates two of the nation's three existing low-level radioactive waste (LLRW) disposal facilities and has prepared and submitted license applications for two new LLRW disposal facilities in California and Nebraska. The issue of financial assurances is an important aspect of site development and operation. Proper financial assurances help to insure that uninterrupted operation, closure and monitoring of a facility will be maintained throughout the project's life. Unfortunately, this aspect of licensing is not like others where you can gauge acceptance by examining approved computer codes, site performance standards or applying specific technical formulas. There is not a standard financial assurance plan. Each site should develop its requirements based upon the conditions of the site, type of design, existing state or federal controls, and realistic assessments of future financial needs. Financial assurances at U.S. Ecology's existing sites in Richland, Washington, and Beatty, Nevada, have been in place for several years and are accomplished in a variety of ways by the use of corporate guarantees, corporate capital funds, third party liability insurance, and post closure/long-term care funds. In addressing financial assurances, one can divide the issue into three areas: Site development/operations, third party damages, and long-term care/cleanup

  5. Flow assurance

    Energy Technology Data Exchange (ETDEWEB)

    Mullins, O.C.; Dong, C. [Schlumberger-Doll Research Center, Cambridge, MA (United States); Elshahawi, H. [Shell Exploration and Production Company, The Hague (Netherlands)

    2008-07-01

    This study emphasized the need for considering flow assurance for producing oil and gas, particularly in high cost areas such as deepwater. Phase behaviour studies, sticking propensities, and interfacial interactions have been investigated in many laboratory studies using asphaltenes, wax, hydrates, organic and inorganic scale, and even diamondoids. However, the spatial variation of reservoir fluids has received little attention, despite the fact that it is one of the most important factors affecting flow assurance. This issue was difficult to address in a systematic way in the past because of cost constraints. Today, reservoir fluid variation and flow assurance can be considered at the outset of a project given the technological advances in downhole fluid analysis. This study described the origins of reservoir fluid compositional variations and the controversies surrounding them. It also described the indispensable chemical analytical technology. The impact of these reservoir fluid compositional variations on flow assurance considerations was also discussed. A methodology that accounts for these variations at the outset in flow assurance evaluation was also presented.

  6. Quality assurance and quality control in light stable isotope laboratories: A case study of Rio Grande, Texas, water samples

    Science.gov (United States)

    Coplen, T.B.; Qi, H.

    2009-01-01

    New isotope laboratories can achieve the goal of reporting the same isotopic composition within analytical uncertainty for the same material analysed decades apart by (1) writing their own acceptance testing procedures and putting them into their mass spectrometric or laser-based isotope-ratio equipment procurement contract, (2) requiring a manufacturer to demonstrate acceptable performance using all sample ports provided with the instrumentation, (3) for each medium to be analysed, prepare two local reference materials substantially different in isotopic composition to encompass the range in isotopic composition expected in the laboratory and calibrated them with isotopic reference materials available from the International Atomic Energy Agency (IAEA) or the US National Institute of Standards and Technology (NIST), (4) using the optimum storage containers (for water samples, sealing in glass ampoules that are sterilised after sealing is satisfactory), (5) interspersing among sample unknowns local laboratory isotopic reference materials daily (internationally distributed isotopic reference materials can be ordered at three-year intervals, and can be used for elemental analyser analyses and other analyses that consume less than 1 mg of material) - this process applies to H, C, N, O, and S isotope ratios, (6) calculating isotopic compositions of unknowns by normalising isotopic data to that of local reference materials, which have been calibrated to internationally distributed isotopic reference materials, (7) reporting results on scales normalised to internationally distributed isotopic reference materials (where they are available) and providing to sample submitters the isotopic compositions of internationally distributed isotopic reference materials of the same substance had they been analysed with unknowns, (8) providing an audit trail in the laboratory for analytical results - this trail commonly will be in electronic format and might include a laboratory

  7. Quality assurance and quality control in light stable isotope laboratories: a case study of Rio Grande, Texas, water samples.

    Science.gov (United States)

    Coplen, Tyler B; Qi, Haiping

    2009-06-01

    New isotope laboratories can achieve the goal of reporting the same isotopic composition within analytical uncertainty for the same material analysed decades apart by (1) writing their own acceptance testing procedures and putting them into their mass spectrometric or laser-based isotope-ratio equipment procurement contract, (2) requiring a manufacturer to demonstrate acceptable performance using all sample ports provided with the instrumentation, (3) for each medium to be analysed, prepare two local reference materials substantially different in isotopic composition to encompass the range in isotopic composition expected in the laboratory and calibrated them with isotopic reference materials available from the International Atomic Energy Agency (IAEA) or the US National Institute of Standards and Technology (NIST), (4) using the optimum storage containers (for water samples, sealing in glass ampoules that are sterilised after sealing is satisfactory), (5) interspersing among sample unknowns local laboratory isotopic reference materials daily (internationally distributed isotopic reference materials can be ordered at three-year intervals, and can be used for elemental analyser analyses and other analyses that consume less than 1 mg of material) - this process applies to H, C, N, O, and S isotope ratios, (6) calculating isotopic compositions of unknowns by normalising isotopic data to that of local reference materials, which have been calibrated to internationally distributed isotopic reference materials, (7) reporting results on scales normalised to internationally distributed isotopic reference materials (where they are available) and providing to sample submitters the isotopic compositions of internationally distributed isotopic reference materials of the same substance had they been analysed with unknowns, (8) providing an audit trail in the laboratory for analytical results - this trail commonly will be in electronic format and might include a laboratory

  8. Using A Particular Sampling Method for Impedance Measurement

    OpenAIRE

    Lentka Grzegorz

    2014-01-01

    The paper presents an impedance measurement method using a particular sampling method which is an alternative to DFT calculation. The method uses a sine excitation signal and sampling response signals proportional to current flowing through and voltage across the measured impedance. The object impedance is calculated without using Fourier transform. The method was first evaluated in MATLAB by means of simulation. The method was then practically verified in a constructed simple impedance measu...

  9. Discussion on fleet test method for radioactive ore sample

    International Nuclear Information System (INIS)

    Testing radionuclides in building materials sample with γ-ray spectrometry has become a commonly used laboratory method, in view of the activity of radioactive ore is ten times more than the building materials sample,its fleet test is possible. It discusses the fleet test method for radioactivity ore sample from the 'social production' point of view. Achieving the test quickly and effectively within error permission, so the method can enhance the efficiency of test and reduce the economic cost. (authors)

  10. γ-ray spectrometry results versus sample preparation methods

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to recommended conditions two bio-samples, tea leave and flour, are prepared with different methods: grounding into powder and reducing to ash, then they were analyzed by γ ray spectrometry. Remarkable difference was shown between the measured values of tea samples prepared with these different methods. One of the reasons may be that the method of reducing to ash makes some nuclides lost. Compared with the "non-destructive"method of grounding into powder, the method of reducing to ash can be much more sensible to the loss of some nuclides. The probable reasons are discussed for the varied influences of different preparation methods of tea leave and flour samples.

  11. γ-ray spectrometry results versus sample preparation methods

    International Nuclear Information System (INIS)

    According to recommended conditions two bio-samples, tea leave and flour, are prepared with different methods: grounding into powder and reducing to ash, then they were analyzed by γ ray spectrometry. Remarkable difference was shown between the measured values of tea samples prepared with these different methods. One of the reasons may be that the method of reducing to ash makes some nuclides lost. Compared with the 'non-destructive' method of grounding into powder, the method of reducing to ash can be much more sensible to the loss of some nuclides. The probable reasons are discussed for the varied influences of different preparation methods of tea leave and flour samples

  12. Systems and methods for self-synchronized digital sampling

    Science.gov (United States)

    Samson, Jr., John R. (Inventor)

    2008-01-01

    Systems and methods for self-synchronized data sampling are provided. In one embodiment, a system for capturing synchronous data samples is provided. The system includes an analog to digital converter adapted to capture signals from one or more sensors and convert the signals into a stream of digital data samples at a sampling frequency determined by a sampling control signal; and a synchronizer coupled to the analog to digital converter and adapted to receive a rotational frequency signal from a rotating machine, wherein the synchronizer is further adapted to generate the sampling control signal, and wherein the sampling control signal is based on the rotational frequency signal.

  13. A method for selecting training samples based on camera response

    Science.gov (United States)

    Zhang, Leihong; Li, Bei; Pan, Zilan; Liang, Dong; Kang, Yi; Zhang, Dawei; Ma, Xiuhua

    2016-09-01

    In the process of spectral reflectance reconstruction, sample selection plays an important role in the accuracy of the constructed model and in reconstruction effects. In this paper, a method for training sample selection based on camera response is proposed. It has been proved that the camera response value has a close correlation with the spectral reflectance. Consequently, in this paper we adopt the technique of drawing a sphere in camera response value space to select the training samples which have a higher correlation with the test samples. In addition, the Wiener estimation method is used to reconstruct the spectral reflectance. Finally, we find that the method of sample selection based on camera response value has the smallest color difference and root mean square error after reconstruction compared to the method using the full set of Munsell color charts, the Mohammadi training sample selection method, and the stratified sampling method. Moreover, the goodness of fit coefficient of this method is also the highest among the four sample selection methods. Taking all the factors mentioned above into consideration, the method of training sample selection based on camera response value enhances the reconstruction accuracy from both the colorimetric and spectral perspectives.

  14. Methods for collecting benthic invertebrate samples as part of the National Water-Quality Assessment Program

    Science.gov (United States)

    Cuffney, Thomas F.; Gurtz, Martin E.; Meador, Michael R.

    1993-01-01

    Benthic invertebrate communities are evaluated as part of the ecological survey component of the U.S. Geological Survey's National Water-Quality Assessment Program. These biological data are collected along with physical and chemical data to assess water-quality conditions and to develop an understanding of the factors that affect water-quality conditions locally, regionally, and nationally. The objectives of benthic invertebrate community characterizations are to (1) develop for each site a list of tax a within the associated stream reach and (2) determine the structure of benthic invertebrate communities within selected habitats of that reach. A nationally consistent approach is used to achieve these objectives. This approach provides guidance on site, reach, and habitat selection and methods and equipment for qualitative multihabitat sampling and semi-quantitative single habitat sampling. Appropriate quality-assurance and quality-control guidelines are used to maximize the ability to analyze data within and among study units.

  15. SU-E-T-438: Commissioning of An In-Vivo Quality Assurance Method Using the Electronic Portal Imaging Device

    International Nuclear Information System (INIS)

    Purpose: Patient specific pre-treatment quality assurance (QA) using arrays of detectors or film have been the standard approach to assure the correct treatment is delivered to the patient. This QA approach is expensive, labor intensive and does not guarantee or document that all remaining fractions were treated properly. The purpose of this abstract is to commission and evaluate the performance of a commercially available in-vivo QA software using the electronic portal imaging device (EPID) to record the daily treatments. Methods: The platform EPIgray V2.0.2 (Dosisoft), which machine model compares ratios of TMR with EPID signal to predict dose was commissioned for an Artiste (Siemens Oncology Care Systems) and a Truebeam (Varian medical systems) linear accelerator following the given instructions. The systems were then tested on three different phantoms (homogeneous stack of solid water, anthropomorphic head and pelvis) and on a library of patient cases. Simple and complex fields were delivered at different exposures and for different gantry angles. The effects of the table attenuation and the EPID sagging were evaluated. Gamma analysis of the measured dose was compared to the predicted dose for complex clinical IMRT cases. Results: Commissioning of the EPIgray system for two photon energies took 8 hours. The difference between the dose planned and the dose measured with EPIgray was better than 3% for all phantom scenarios tested. Preliminary results on patients demonstrate an accuracy of 5% is achievable in high dose regions for both 3DCRT and IMRT. Large discrepancies (>5%) were observed due to metallic structures or air cavities and in low dose areas. Flat panel sagging was visible and accounted for in the EPIgray model. Conclusion: The accuracy achieved by EPIgray is sufficient to document the safe delivery of complex IMRT treatments. Future work will evaluate EPIgray for VMAT and high dose rate deliveries. This work is supported by Dosisoft, Cachan, France

  16. Passive Samplers for Investigations of Air Quality: Method Description, Implementation, and Comparison to Alternative Sampling Methods

    Science.gov (United States)

    This Paper covers the basics of passive sampler design, compares passive samplers to conventional methods of air sampling, and discusses considerations when implementing a passive sampling program. The Paper also discusses field sampling and sample analysis considerations to ensu...

  17. Rapid screening methods for beta-emitters in food samples

    International Nuclear Information System (INIS)

    In case of a nuclear emergency, many samples need to be measured in a short time period. Therefore, it is of vital importance to have a quick and reliable (screening)method. Most methods to determine total beta activity are time-consuming because of extensive sample preparation, such as ashing. In this article three different rapid screening methods for beta emitting nuclides in agriculture, livestock and fishery products were tested and compared to each other, and to an accurate but more time consuming reference method. The goal was to find the method with the optimal trade-off between accuracy, speed and minimal detectable activity (MDA). All of the methods rely on liquid scintillation counting (LSC) or Cerenkov counting, and differ mainly in sample preparation. For matrices with little or no colour, the direct LSC-method is the most accurate and fastest option, while for darker coloured samples this method is not suitable because of high colour quenching. For such samples, two additional methods using a microwave digestion during sample preparation, produced good results. - Highlights: • Comparison of rapid screening methods for beta-emitters. • Sample preparation and measurement done within 1.5–7.5 h instead of 56 h. • MDA less than 100 Bq/kg fresh product. • Recoveries for all rapid screening methods higher than 73%

  18. Computerized method for radiologic system parameter simulations destined for quality assurance programs

    International Nuclear Information System (INIS)

    The objective of this work is to develop a computational simulation method that allows for fast radiographical image quality evaluations that are devoid of the problems inherent to the traditional methods used to date. The algorithms implemented take into consideration the focal spot size and intensity distribution, the geometric conditions of exposure, the angular X-ray distribution (heel effect), the Compton effect and the anti-scatter grids (Bucky). (author)

  19. DOE methods for evaluating environmental and waste management samples

    International Nuclear Information System (INIS)

    DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods) provides applicable methods in use by. the US Department of Energy (DOE) laboratories for sampling and analyzing constituents of waste and environmental samples. The development of DOE Methods is supported by the Laboratory Management Division (LMD) of the DOE. This document contains chapters and methods that are proposed for use in evaluating components of DOE environmental and waste management samples. DOE Methods is a resource intended to support sampling and analytical activities that will aid in defining the type and breadth of contamination and thus determine the extent of environmental restoration or waste management actions needed, as defined by the DOE, the US Environmental Protection Agency (EPA), or others

  20. DOE methods for evaluating environmental and waste management samples.

    Energy Technology Data Exchange (ETDEWEB)

    Goheen, S C; McCulloch, M; Thomas, B L; Riley, R G; Sklarew, D S; Mong, G M; Fadeff, S K [eds.; Pacific Northwest Lab., Richland, WA (United States)

    1994-04-01

    DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods) provides applicable methods in use by. the US Department of Energy (DOE) laboratories for sampling and analyzing constituents of waste and environmental samples. The development of DOE Methods is supported by the Laboratory Management Division (LMD) of the DOE. This document contains chapters and methods that are proposed for use in evaluating components of DOE environmental and waste management samples. DOE Methods is a resource intended to support sampling and analytical activities that will aid in defining the type and breadth of contamination and thus determine the extent of environmental restoration or waste management actions needed, as defined by the DOE, the US Environmental Protection Agency (EPA), or others.

  1. THE USE OF RANKING SAMPLING METHOD WITHIN MARKETING RESEARCH

    Directory of Open Access Journals (Sweden)

    CODRUŢA DURA

    2011-01-01

    Full Text Available Marketing and statistical literature available to practitioners provides a wide range of sampling methods that can be implemented in the context of marketing research. Ranking sampling method is based on taking apart the general population into several strata, namely into several subdivisions which are relatively homogenous regarding a certain characteristic. In fact, the sample will be composed by selecting, from each stratum, a certain number of components (which can be proportional or non-proportional to the size of the stratum until the pre-established volume of the sample is reached. Using ranking sampling within marketing research requires the determination of some relevant statistical indicators - average, dispersion, sampling error etc. To that end, the paper contains a case study which illustrates the actual approach used in order to apply the ranking sample method within a marketing research made by a company which provides Internet connection services, on a particular category of customers – small and medium enterprises.

  2. Use of destructive and nondestructive methods of analysis for quality assurance at MOX fuel production in the Russia

    International Nuclear Information System (INIS)

    Parameters of MOX fuel with various plutonium contents are considered from the point of view of necessity of their control for quality assurance. Destructive and nondestructive methods used for this purpose in the Russia are described: controlled potential coulometry for determination of uranium or/and plutonium contents, their ratio and oxygen factor; mass spectrometry for determination of uranium and plutonium isotopic composition; chemical spectral emission method for determination of contents of 'metal' impurities, boron and silicon, and methods of determination of gas forming impurities. Capabilities of nondestructive gamma-ray spectrometry techniques are considered in detail and results of their use at measurement of uranium and plutonium isotopic composition in initial dioxides, at determination of contents of uranium and plutonium, and uniformity of their distribution in MOX powder and pellets. The necessity of correction of algorithm of the MGA program is shown for using the program at analyses of gamma-ray spectra of MOX with low contents of low burnup plutonium. (authors)

  3. Use of destructive and nondestructive methods of analysis for quality assurance at MOX fuel production in the Russia

    Energy Technology Data Exchange (ETDEWEB)

    Bibilashvili, Y.K.; Rudenko, V.S.; Chorokhov, N.A.; Korovin, Y.I.; Petrov, A.M.; Vorobiev, A.V.; Mukhortov, N.F.; Smirnov, Y.A.; Kudryavtsev, V.N. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (Russian Federation)

    2000-07-01

    Parameters of MOX fuel with various plutonium contents are considered from the point of view of necessity of their control for quality assurance. Destructive and nondestructive methods used for this purpose in the Russia are described: controlled potential coulometry for determination of uranium or/and plutonium contents, their ratio and oxygen factor; mass spectrometry for determination of uranium and plutonium isotopic composition; chemical spectral emission method for determination of contents of 'metal' impurities, boron and silicon, and methods of determination of gas forming impurities. Capabilities of nondestructive gamma-ray spectrometry techniques are considered in detail and results of their use at measurement of uranium and plutonium isotopic composition in initial dioxides, at determination of contents of uranium and plutonium, and uniformity of their distribution in MOX powder and pellets. The necessity of correction of algorithm of the MGA program is shown for using the program at analyses of gamma-ray spectra of MOX with low contents of low burnup plutonium. (authors)

  4. Quality assurance using outlier detection on an automatic segmentation method for the cerebellar peduncles

    Science.gov (United States)

    Li, Ke; Ye, Chuyang; Yang, Zhen; Carass, Aaron; Ying, Sarah H.; Prince, Jerry L.

    2016-03-01

    Cerebellar peduncles (CPs) are white matter tracts connecting the cerebellum to other brain regions. Automatic segmentation methods of the CPs have been proposed for studying their structure and function. Usually the performance of these methods is evaluated by comparing segmentation results with manual delineations (ground truth). However, when a segmentation method is run on new data (for which no ground truth exists) it is highly desirable to efficiently detect and assess algorithm failures so that these cases can be excluded from scientific analysis. In this work, two outlier detection methods aimed to assess the performance of an automatic CP segmentation algorithm are presented. The first one is a univariate non-parametric method using a box-whisker plot. We first categorize automatic segmentation results of a dataset of diffusion tensor imaging (DTI) scans from 48 subjects as either a success or a failure. We then design three groups of features from the image data of nine categorized failures for failure detection. Results show that most of these features can efficiently detect the true failures. The second method—supervised classification—was employed on a larger DTI dataset of 249 manually categorized subjects. Four classifiers—linear discriminant analysis (LDA), logistic regression (LR), support vector machine (SVM), and random forest classification (RFC)—were trained using the designed features and evaluated using a leave-one-out cross validation. Results show that the LR performs worst among the four classifiers and the other three perform comparably, which demonstrates the feasibility of automatically detecting segmentation failures using classification methods.

  5. Engineering Study of 500 ML Sample Bottle Transportation Methods

    International Nuclear Information System (INIS)

    This engineering study reviews and evaluates all available methods for transportation of 500-mL grab sample bottles, reviews and evaluates transportation requirements and schedules and analyzes and recommends the most cost-effective method for transporting 500-mL grab sample bottles

  6. Engineering Study of 500 ML Sample Bottle Transportation Methods

    Energy Technology Data Exchange (ETDEWEB)

    BOGER, R.M.

    1999-08-25

    This engineering study reviews and evaluates all available methods for transportation of 500-mL grab sample bottles, reviews and evaluates transportation requirements and schedules and analyzes and recommends the most cost-effective method for transporting 500-mL grab sample bottles.

  7. GROUND WATER PURGING AND SAMPLING METHODS: HISTORY VS. HYSTERIA

    Science.gov (United States)

    It has been over 10 years since the low-flow ground water purging and sampling method was initially reported in the literature. The method grew from the recognition that well purging was necessary to collect representative samples, bailers could not achieve well purging, and high...

  8. HISTORICAL APPROACH TO THE USE OF SAMPLING METHODS

    OpenAIRE

    Dobrunova M. A.

    2015-01-01

    The article describes the historical approach to the use of sampling, both in Russia and abroad. The above classification of the main stages in the development of the sampling method in science made it possible to determine the practical significance of the use of this method in the audit practice

  9. Rapid method for sampling metals for materials identification

    Science.gov (United States)

    Higgins, L. E.

    1971-01-01

    Nondamaging process similar to electrochemical machining is useful in obtaining metal samples from places inaccessible to conventional sampling methods or where methods would be hazardous or contaminating to specimens. Process applies to industries where metals or metal alloys play a vital role.

  10. Fast Efficient Importance Sampling by State Space Methods

    OpenAIRE

    Koopman, S.J.; Nguyen, T.M.

    2012-01-01

    We show that efficient importance sampling for nonlinear non-Gaussian state space models can be implemented by computationally efficient Kalman filter and smoothing methods. The result provides some new insights but it primarily leads to a simple and fast method for efficient importance sampling. A simulation study and empirical illustration provide some evidence of the computational gains.

  11. DOE methods for evaluating environmental and waste management samples

    International Nuclear Information System (INIS)

    This publication provides applicable methods in use by the US Department of Energy (DOE) laboratories for the analysis of constituents of waste and environmental samples. This document contains chapters and methods that are proposed for use in evaluating components of DOE environmental and waste management samples. It is a resource intended to support sampling and analytical activities that will determine whether environmental restoration or waste management actions are needed, as defined by the DOE, the US Environmental Protection Agency (EPA), or others

  12. THE USE OF RANKING SAMPLING METHOD WITHIN MARKETING RESEARCH

    OpenAIRE

    CODRUŢA DURA; IMOLA DRIGĂ

    2011-01-01

    Marketing and statistical literature available to practitioners provides a wide range of sampling methods that can be implemented in the context of marketing research. Ranking sampling method is based on taking apart the general population into several strata, namely into several subdivisions which are relatively homogenous regarding a certain characteristic. In fact, the sample will be composed by selecting, from each stratum, a certain number of components (which can be proportional or non-...

  13. QUALITY ASSURANCE METHODS MANUAL FOR FOREST SITE CLASSIFICATION AND FIELD MEASUREMENTS

    Science.gov (United States)

    The main objective of this third version of this manual is to provide a set of standardized, technically sound and well documented, methods that would allow data or measurement precision and bias to be estimated and controlled, and thus promote the comparabiLity of forestry fieLd...

  14. Selection criteria for a sampling method in the statistical research

    Directory of Open Access Journals (Sweden)

    DĂNUŢ-VASILE JEMNA

    2006-01-01

    Full Text Available In the practice of statistical researches no one method of sampling is the best. But, to plan a statistical research, demand a selecting process for a sampling method from a set of possibilities. To obtain the most appropriate method of sampling concerns to use a set of selection criteria.The aim of this paper is to present such a set and to emphasis some issues concerning the selection process of a sampling method using the specificity of each criterion. We start to point up that a first set of criteria is indicating by the limits of the possibilities of statistical knowledge. Another sources of limits for selecting a sampling method are the economic restrictions and the time to achieve the research.

  15. Evaluation of common methods for sampling invertebrate pollinator assemblages: net sampling out-perform pan traps.

    Directory of Open Access Journals (Sweden)

    Tony J Popic

    Full Text Available Methods for sampling ecological assemblages strive to be efficient, repeatable, and representative. Unknowingly, common methods may be limited in terms of revealing species function and so of less value for comparative studies. The global decline in pollination services has stimulated surveys of flower-visiting invertebrates, using pan traps and net sampling. We explore the relative merits of these two methods in terms of species discovery, quantifying abundance, function, and composition, and responses of species to changing floral resources. Using a spatially-nested design we sampled across a 5000 km(2 area of arid grasslands, including 432 hours of net sampling and 1296 pan trap-days, between June 2010 and July 2011. Net sampling yielded 22% more species and 30% higher abundance than pan traps, and better reflected the spatio-temporal variation of floral resources. Species composition differed significantly between methods; from 436 total species, 25% were sampled by both methods, 50% only by nets, and the remaining 25% only by pans. Apart from being less comprehensive, if pan traps do not sample flower-visitors, the link to pollination is questionable. By contrast, net sampling functionally linked species to pollination through behavioural observations of flower-visitation interaction frequency. Netted specimens are also necessary for evidence of pollen transport. Benefits of net-based sampling outweighed minor differences in overall sampling effort. As pan traps and net sampling methods are not equivalent for sampling invertebrate-flower interactions, we recommend net sampling of invertebrate pollinator assemblages, especially if datasets are intended to document declines in pollination and guide measures to retain this important ecosystem service.

  16. Evaluation of common methods for sampling invertebrate pollinator assemblages: net sampling out-perform pan traps.

    Science.gov (United States)

    Popic, Tony J; Davila, Yvonne C; Wardle, Glenda M

    2013-01-01

    Methods for sampling ecological assemblages strive to be efficient, repeatable, and representative. Unknowingly, common methods may be limited in terms of revealing species function and so of less value for comparative studies. The global decline in pollination services has stimulated surveys of flower-visiting invertebrates, using pan traps and net sampling. We explore the relative merits of these two methods in terms of species discovery, quantifying abundance, function, and composition, and responses of species to changing floral resources. Using a spatially-nested design we sampled across a 5000 km(2) area of arid grasslands, including 432 hours of net sampling and 1296 pan trap-days, between June 2010 and July 2011. Net sampling yielded 22% more species and 30% higher abundance than pan traps, and better reflected the spatio-temporal variation of floral resources. Species composition differed significantly between methods; from 436 total species, 25% were sampled by both methods, 50% only by nets, and the remaining 25% only by pans. Apart from being less comprehensive, if pan traps do not sample flower-visitors, the link to pollination is questionable. By contrast, net sampling functionally linked species to pollination through behavioural observations of flower-visitation interaction frequency. Netted specimens are also necessary for evidence of pollen transport. Benefits of net-based sampling outweighed minor differences in overall sampling effort. As pan traps and net sampling methods are not equivalent for sampling invertebrate-flower interactions, we recommend net sampling of invertebrate pollinator assemblages, especially if datasets are intended to document declines in pollination and guide measures to retain this important ecosystem service. PMID:23799127

  17. A Mixed Methods Sampling Methodology for a Multisite Case Study

    Science.gov (United States)

    Sharp, Julia L.; Mobley, Catherine; Hammond, Cathy; Withington, Cairen; Drew, Sam; Stringfield, Sam; Stipanovic, Natalie

    2012-01-01

    The flexibility of mixed methods research strategies makes such approaches especially suitable for multisite case studies. Yet the utilization of mixed methods to select sites for these studies is rarely reported. The authors describe their pragmatic mixed methods approach to select a sample for their multisite mixed methods case study of a…

  18. Using A Particular Sampling Method for Impedance Measurement

    Directory of Open Access Journals (Sweden)

    Lentka Grzegorz

    2014-08-01

    Full Text Available The paper presents an impedance measurement method using a particular sampling method which is an alternative to DFT calculation. The method uses a sine excitation signal and sampling response signals proportional to current flowing through and voltage across the measured impedance. The object impedance is calculated without using Fourier transform. The method was first evaluated in MATLAB by means of simulation. The method was then practically verified in a constructed simple impedance measurement instrument based on a PSoC (Programmable System on Chip. The obtained calculation simplification recommends the method for implementation in simple portable impedance analyzers destined for operation in the field or embedding in sensors.

  19. Evaluation of Common Methods for Sampling Invertebrate Pollinator Assemblages: Net Sampling Out-Perform Pan Traps

    OpenAIRE

    Popic, Tony J.; Davila, Yvonne C.; Wardle, Glenda M.

    2013-01-01

    Methods for sampling ecological assemblages strive to be efficient, repeatable, and representative. Unknowingly, common methods may be limited in terms of revealing species function and so of less value for comparative studies. The global decline in pollination services has stimulated surveys of flower-visiting invertebrates, using pan traps and net sampling. We explore the relative merits of these two methods in terms of species discovery, quantifying abundance, function, and composition, an...

  20. Quality assurance and statistical control

    DEFF Research Database (Denmark)

    Heydorn, K.

    1991-01-01

    In scientific research laboratories it is rarely possible to use quality assurance schemes, developed for large-scale analysis. Instead methods have been developed to control the quality of modest numbers of analytical results by relying on statistical control: Analysis of precision serves to...... through the origo. Calibration control is an essential link in the traceability of results. Only one or two samples of pure solid or aqueous standards with accurately known content need to be analyzed. Verification is carried out by analyzing certified reference materials from BCR, NIST, or others; their...

  1. Validation of analysis results of ground air samples - using different sampling and analysis methods

    International Nuclear Information System (INIS)

    In the laboratory different techniques for ground air sampling were compared to each other. For this purpose constant mixtures of gases were produced with gas mixing systems and the samples were taken using different sampling techniques in the same way as usually done in situ. A mixture of different chlorinated hydrocarbons in three different concentrations was analysed. It resulted that all sampling methods testes can be considered as equally suited with regard to the quality of the measuring results. But with regard to other evaluation criteria such as e.g. the limit of determination or sample volume they differ considerably. (orig.)

  2. Rapid screening methods for beta-emitters in food samples.

    Science.gov (United States)

    Vos van Avezathe, A; Brandhoff, P N; van Bourgondiën, M J; Krijger, G C

    2015-03-01

    In case of a nuclear emergency, many samples need to be measured in a short time period. Therefore, it is of vital importance to have a quick and reliable (screening)method. Most methods to determine total beta activity are time-consuming because of extensive sample preparation, such as ashing. In this article three different rapid screening methods for beta emitting nuclides in agriculture, livestock and fishery products were tested and compared to each other, and to an accurate but more time consuming reference method. The goal was to find the method with the optimal trade-off between accuracy, speed and minimal detectable activity (MDA). All of the methods rely on liquid scintillation counting (LSC) or Cerenkov counting, and differ mainly in sample preparation. For matrices with little or no colour, the direct LSC-method is the most accurate and fastest option, while for darker coloured samples this method is not suitable because of high colour quenching. For such samples, two additional methods using a microwave digestion during sample preparation, produced good results. PMID:25577324

  3. Application of the SAMR method to high magnetostrictive samples

    Science.gov (United States)

    Sanchez, P.; Lopez, E.; Trujillo, M. C. Sanchez; Aroca, C.

    1988-12-01

    Magnetostriction measurement by using the small angle magnetization rotation method (SAMR) has been performed in high magnetostrictive amorphous samples. To apply the SAMR method to these samples, a theoritical model about the influence of the internal stresses and magnetization distribution has been proposed. The dependence of the magnetostriction, λ s, with the temperature and applied stress was measured in as-cast and in different annealed samples. In the as-cast samples the existence of a stray field and a dependence of λ s with the applied stress has been observed.

  4. RAPID-TRANSIT EFFICIENCY ANALYSIS WITH THE ASSURANCE-REGION DEA METHOD

    Directory of Open Access Journals (Sweden)

    Antonio G.N. Novaes

    2001-07-01

    Full Text Available Rapid-transit services are a relevant part of the transportation network in most cities of the world. An important aspect of transport policy is the supply of public urban transportation. In particular, it is of interest to determine whether rapid-transit operators are working in a technically and scale-efficient way. Production analysis of transit services has been characterized by the econometric study of average practice technologies. A more recent method to study such production frontiers is Data Envelopment Analysis (DEA. It is a non-parametric method, but its application to rapid-transit, where the relations among technological variables are more strict, requires a previous structural analysis of the intervening inputs and outputs. DEA is employed in this paper to investigate the efficiency and returns to scale of 21 rapid-transit properties of the world. DEA was also used for the benchmarking of non-efficient rapid-transit properties, with special emphasis to the São Paulo’s subway systemOs sistemas de metrô são parte relevante do transporte em muitas cidades do globo. Um aspecto importante da política de transportes é a oferta. Nesse contexto, é de interesse verificar se os operadores estão trabalhando de maneira eficiente, em termos técnicos, e no que diz respeito a ganhos de escala. A análise do processo de produção de metrôs tem sido realizada através de estudos econométricos baseados em práticas tecnológicas médias. Um método mais recente para estudar fronteiras de produção é a Análise Envoltória de Dados (DEA. Trata-se de um método não-paramétrico, mas suas aplicações a metrôs, que envolvem relações mais rígidas entre as variáveis tecnológicas, requerem uma análise prévia dos inputs e dos outputs. DEA é utilizada no artigo para analisar a eficiência e ganhos de escala de 21 metrôs. É também utilizada como instrumento auxiliar no benchmarking de metrôs não eficientes, com ênfase ao metr

  5. DOE methods for evaluating environmental and waste management samples

    International Nuclear Information System (INIS)

    DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods) is a resource intended to support sampling and analytical activities for the evaluation of environmental and waste management samples from U.S. Department of Energy (DOE) sites. DOE Methods is the result of extensive cooperation from all DOE analytical laboratories. All of these laboratories have contributed key information and provided technical reviews as well as significant moral support leading to the success of this document. DOE Methods is designed to encompass methods for collecting representative samples and for determining the radioisotope activity and organic and inorganic composition of a sample. These determinations will aid in defining the type and breadth of contamination and thus determine the extent of environmental restoration or waste management actions needed, as defined by the DOE, the U.S. Environmental Protection Agency, or others. The development of DOE Methods is supported by the Laboratory Management Division of the DOE. Methods are prepared for entry into DOE Methods as chapter editors, together with DOE and other participants in this program, identify analytical and sampling method needs. Unique methods or methods consolidated from similar procedures in the DOE Procedures Database are selected for potential inclusion in this document. Initial selection is based largely on DOE needs and procedure applicability and completeness. Methods appearing in this document are one of two types. open-quotes Draftclose quotes or open-quotes Verified.close quotes. open-quotes Draftclose quotes methods that have been reviewed internally and show potential for eventual verification are included in this document, but they have not been reviewed externally, and their precision and bias may not be known. open-quotes Verifiedclose quotes methods in DOE Methods have been reviewed by volunteers from various DOE sites and private corporations

  6. SU-E-J-126: Respiratory Gating Quality Assurance: A Simple Method to Achieve Millisecond Temporal Resolution

    International Nuclear Information System (INIS)

    Purpose: Low temporal latency between a gating on/off signal and a linac beam on/off during respiratory gating is critical for patient safety. Although, a measurement of temporal lag is recommended by AAPM Task Group 142 for commissioning and annual quality assurance, there currently exists no published method. Here we describe a simple, inexpensive, and reliable method to precisely measure gating lag at millisecond resolutions. Methods: A Varian Real-time Position Management™ (RPM) gating simulator with rotating disk was modified with a resistive flex sensor (Spectra Symbol) attached to the gating box platform. A photon diode was placed at machine isocenter. Output signals of the flex sensor and diode were monitored with a multichannel oscilloscope (Tektronix™ DPO3014). Qualitative inspection of the gating window/beam on synchronicity were made by setting the linac to beam on/off at end-expiration, and the oscilloscope's temporal window to 100 ms to visually examine if the on/off timing was within the recommended 100-ms tolerance. Quantitative measurements were made by saving the signal traces and analyzing in MatLab™. The on and off of the beam signal were located and compared to the expected gating window (e.g. 40% to 60%). Four gating cycles were measured and compared. Results: On a Varian TrueBeam™ STx linac with RPM gating software, the average difference in synchronicity at beam on and off for four cycles was 14 ms (3 to 30 ms) and 11 ms (2 to 32 ms), respectively. For a Varian Clinac™ 21EX the average difference at beam on and off was 127 ms (122 to 133 ms) and 46 ms (42 to 49 ms), respectively. The uncertainty in the synchrony difference was estimated at ±6 ms. Conclusion: This new gating QA method is easy to implement and allows for fast qualitative inspection and quantitative measurements for commissioning and TG-142 annual QA measurements

  7. Developing a novel method to analyse Gafchromic EBT2 films in intensity modulated radiation therapy quality assurance

    International Nuclear Information System (INIS)

    Recently individual intensity modulated radiation therapy quality assurances (IMRT QA) have been more and more performed with Gafchromic™ EBT series films processed in red–green–blue (R–G–B) channel due to their extremely high spatial resolution. However, the efficiency of this method is relatively low, as for each box of film, a calibration curve must be established prior to the film being used for measurement. In this study, the authors find a novel method to process the Gafchromic™ EBT series, that is, to use the 16-bit grey scale channel to process the exposed film rather than the conventional 48-bit R–G–B channel, which greatly increases the efficiency and even accuracy of the whole IMRT procedure. The main advantage is that when processed in grey scale channel, the Gafchromic™ EBT2 films exhibits a linear relationship between the net pixel value and the dose delivered. This linear relationship firstly reduces the error in calibration-curve fitting, and secondly saves the need of establishing a calibration curve for each box of films if it is only to be used for relative measurements. Clinical testing for this novel method was carried out in two radiation therapy centres that involved a total of 743 IMRT cases, and 740 cases passed the 3 mm 3 % gamma analysis criteria. The cases were also tested with small ionization chambers (cc-13) and the results were convincing. Consequently the authors recommend the use of this novel method to improve the accuracy and efficiency of individual IMRT QA procedure using Gafchromic EBT2 films.

  8. Quality assurance

    International Nuclear Information System (INIS)

    Quality checks are essential to assure production of high quality plants and to have end-users confidence. Quality standards require the establishment of suitable tests to maintain quality control. The choice of explant source, freedom of the donor plant from viruses, disease causing fungi, bacteria, viroids, phytoplasmas, vigour and conformity of the variety, and elimination of somaclonal variants are critical for maintaining plant quality. Variety identification by proper labeling at all stages is essential to ensure varietal identity. (author)

  9. Comparative analysis among sampling methods of underground water

    Directory of Open Access Journals (Sweden)

    Fábio Augusto Gomes Vieira Reis

    2005-06-01

    Full Text Available The monitoring of the underground water quality assumes importance because of the increasing use of it for the different purposes of the contemporaneous society. Different methods for sampling and monitoring of underground water can take to very distinct results. In this way, the present work has as objective to carry out comparative studies among three methods of sampling of underground waters. Bailer, Electric pump of high flowing and pump of low flowing. Quantitative and qualitative sampling techniques of water quality were opted through monitoring wells. The research involved the identification and analysis of the differences in the results obtained by the methods of sampling of underground waters; the geologic and hydrologic description of the monitoring well, on which the sampling was taken from; and the comparative analysis among the three methods of sampling, determining which ones present the best efficiency. There were made mensurations at the site, collection of samples and interpretation of the chemical analyses. At the end of the works, with the integration of the geologic and hydrologic data and analytic results was possible to indicate that the most precise method of sampling of underground water is the low flowing one.

  10. A survey of bootstrap methods in finite population sampling

    Directory of Open Access Journals (Sweden)

    Zeinab Mashreghi

    2016-03-01

    Full Text Available We review bootstrap methods in the context of survey data where the effect of the sampling design on the variability of estimators has to be taken into account. We present the methods in a unified way by classifying them in three classes: pseudo-population, direct, and survey weights methods. We cover variance estimation and the construction of confidence intervals for stratified simple random sampling as well as some unequal probability sampling designs. We also address the problem of variance estimation in presence of imputation to compensate for item non-response.

  11. Sampling and analysis methods for geothermal fluids and gases

    Energy Technology Data Exchange (ETDEWEB)

    Watson, J.C.

    1978-07-01

    The sampling procedures for geothermal fluids and gases include: sampling hot springs, fumaroles, etc.; sampling condensed brine and entrained gases; sampling steam-lines; low pressure separator systems; high pressure separator systems; two-phase sampling; downhole samplers; and miscellaneous methods. The recommended analytical methods compiled here cover physical properties, dissolved solids, and dissolved and entrained gases. The sequences of methods listed for each parameter are: wet chemical, gravimetric, colorimetric, electrode, atomic absorption, flame emission, x-ray fluorescence, inductively coupled plasma-atomic emission spectroscopy, ion exchange chromatography, spark source mass spectrometry, neutron activation analysis, and emission spectrometry. Material on correction of brine component concentrations for steam loss during flashing is presented. (MHR)

  12. Method of analysis and quality-assurance practices by the U. S. Geological Survey Organic Geochemistry Research Group; determination of four selected mosquito insecticides and a synergist in water using liquid-liquid extraction and gas chrom

    Science.gov (United States)

    Zimmerman, L.R.; Strahan, A.P.; Thurman, E.M.

    2001-01-01

    A method of analysis and quality-assurance practices were developed for the determination of four mosquito insecticides (malathion, metho-prene, phenothrin, and resmethrin) and one synergist (piperonyl butoxide) in water. The analytical method uses liquid-liquid extraction (LLE) and gas chromatography/mass spectrometry (GC/MS). Good precision and accuracy were demonstrated in reagent water, urban surface water, and ground water. The mean accuracies as percentages of the true compound concentrations from water samples spiked at 10 and 50 nanograms per liter ranged from 68 to 171 percent, with standard deviations in concentrations of 27 nanograms per liter or less. The method detection limit for all compounds was 5.9 nanograms per liter or less for 247-milliliter samples. This method is valuable for acquiring information about the fate and transport of these mosquito insecticides and one synergist in water.

  13. Field Sample Preparation Method Development for Isotope Ratio Mass Spectrometry

    International Nuclear Information System (INIS)

    Non-proliferation and International Security (NA-241) established a working group of researchers from Los Alamos National Laboratory (LANL), Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) to evaluate the utilization of in-field mass spectrometry for safeguards applications. The survey of commercial off-the-shelf (COTS) mass spectrometers (MS) revealed no instrumentation existed capable of meeting all the potential safeguards requirements for performance, portability, and ease of use. Additionally, fieldable instruments are unlikely to meet the International Target Values (ITVs) for accuracy and precision for isotope ratio measurements achieved with laboratory methods. The major gaps identified for in-field actinide isotope ratio analysis were in the areas of: 1. sample preparation and/or sample introduction, 2. size reduction of mass analyzers and ionization sources, 3. system automation, and 4. decreased system cost. Development work in 2 through 4, numerated above continues, in the private and public sector. LANL is focusing on developing sample preparation/sample introduction methods for use with the different sample types anticipated for safeguard applications. Addressing sample handling and sample preparation methods for MS analysis will enable use of new MS instrumentation as it becomes commercially available. As one example, we have developed a rapid, sample preparation method for dissolution of uranium and plutonium oxides using ammonium bifluoride (ABF). ABF is a significantly safer and faster alternative to digestion with boiling combinations of highly concentrated mineral acids. Actinides digested with ABF yield fluorides, which can then be analyzed directly or chemically converted and separated using established column chromatography techniques as needed prior to isotope analysis. The reagent volumes and the sample processing steps associated with ABF sample digestion lend themselves to automation and field

  14. Field evaluation of personal sampling methods for multiple bioaerosols.

    Science.gov (United States)

    Wang, Chi-Hsun; Chen, Bean T; Han, Bor-Cheng; Liu, Andrew Chi-Yeu; Hung, Po-Chen; Chen, Chih-Yong; Chao, Hsing Jasmine

    2015-01-01

    Ambient bioaerosols are ubiquitous in the daily environment and can affect health in various ways. However, few studies have been conducted to comprehensively evaluate personal bioaerosol exposure in occupational and indoor environments because of the complex composition of bioaerosols and the lack of standardized sampling/analysis methods. We conducted a study to determine the most efficient collection/analysis method for the personal exposure assessment of multiple bioaerosols. The sampling efficiencies of three filters and four samplers were compared. According to our results, polycarbonate (PC) filters had the highest relative efficiency, particularly for bacteria. Side-by-side sampling was conducted to evaluate the three filter samplers (with PC filters) and the NIOSH Personal Bioaerosol Cyclone Sampler. According to the results, the Button Aerosol Sampler and the IOM Inhalable Dust Sampler had the highest relative efficiencies for fungi and bacteria, followed by the NIOSH sampler. Personal sampling was performed in a pig farm to assess occupational bioaerosol exposure and to evaluate the sampling/analysis methods. The Button and IOM samplers yielded a similar performance for personal bioaerosol sampling at the pig farm. However, the Button sampler is more likely to be clogged at high airborne dust concentrations because of its higher flow rate (4 L/min). Therefore, the IOM sampler is a more appropriate choice for performing personal sampling in environments with high dust levels. In summary, the Button and IOM samplers with PC filters are efficient sampling/analysis methods for the personal exposure assessment of multiple bioaerosols. PMID:25799419

  15. Comparison of Methods for Soil Sampling and Carbon Content Determination

    Directory of Open Access Journals (Sweden)

    Željka Zgorelec

    2011-03-01

    Full Text Available In this paper methods for sampling and analysis of total carbon in soil were compared. Soil sampling was done by sampling scheme according to agricultural soil monitoring recommendations. Soil samples were collected as single (four individual probe patterns and composite soil samples (16 individual probe patterns from agriculture soil. In soil samples mass ratio of total soil carbon was analyzed by dry combustion method (according to Dumas; HRN ISO 10694:2004 in Analytical Laboratory of Department of General Agronomy, Faculty of Agriculture University of Zagreb (FAZ and by oxidation method with chromium sulfuric acid (modified HRN ISO 14235:2004 in Analytical laboratory of Croatian Center for Agriculture, Food and Rural Affairs, Department of Soil and Land Conservation (ZZT. The observed data showed very strong correlation (r = 0.8943; n = 42 between two studied methods of analysis. Very strong correlation was also noted between different sampling procedures for single and composite samples in both laboratories, and coefficients of correlation were 0.9697 and 0.9950 (n = 8, respectively.

  16. Field Evaluation of Personal Sampling Methods for Multiple Bioaerosols

    OpenAIRE

    Wang, Chi-Hsun; Chen, Bean T; Han, Bor-Cheng; Liu, Andrew Chi-Yeu; Hung, Po-Chen; Chen, Chih-Yong; Chao, Hsing Jasmine

    2015-01-01

    Ambient bioaerosols are ubiquitous in the daily environment and can affect health in various ways. However, few studies have been conducted to comprehensively evaluate personal bioaerosol exposure in occupational and indoor environments because of the complex composition of bioaerosols and the lack of standardized sampling/analysis methods. We conducted a study to determine the most efficient collection/analysis method for the personal exposure assessment of multiple bioaerosols. The sampling...

  17. Comparative analysis among sampling methods of underground water

    OpenAIRE

    Fábio Augusto Gomes Vieira Reis; Roberto Soriano Junior

    2005-01-01

    The monitoring of the underground water quality assumes importance because of the increasing use of it for the different purposes of the contemporaneous society. Different methods for sampling and monitoring of underground water can take to very distinct results. In this way, the present work has as objective to carry out comparative studies among three methods of sampling of underground waters. Bailer, Electric pump of high flowing and pump of low flowing. Quantitative and qualitative sampli...

  18. An express method of Cs-137 determination in environmental samples

    International Nuclear Information System (INIS)

    A method for CS-137 determination has been suggested that is based on the use of complex ferro-ferricyanides of transition metals. This method had been approbated at Kozloduj NPP and IRT-2000 reactor in Sofia. A good agreement with the classic method (ceasium sedimentation in the form of Cs2PtCl6) was obtained for measurements of soil, river bed deposition, plant, milk powder and other samples. The described method is easily applicable, non-expensive, does not require high qualification personnel. The radiochemical part of the analysis without preliminary sample treatment takes 12-24 hours

  19. Probability Sampling Method for a Hidden Population Using Respondent-Driven Sampling: Simulation for Cancer Survivors.

    Science.gov (United States)

    Jung, Minsoo

    2015-01-01

    When there is no sampling frame within a certain group or the group is concerned that making its population public would bring social stigma, we say the population is hidden. It is difficult to approach this kind of population survey-methodologically because the response rate is low and its members are not quite honest with their responses when probability sampling is used. The only alternative known to address the problems caused by previous methods such as snowball sampling is respondent-driven sampling (RDS), which was developed by Heckathorn and his colleagues. RDS is based on a Markov chain, and uses the social network information of the respondent. This characteristic allows for probability sampling when we survey a hidden population. We verified through computer simulation whether RDS can be used on a hidden population of cancer survivors. According to the simulation results of this thesis, the chain-referral sampling of RDS tends to minimize as the sample gets bigger, and it becomes stabilized as the wave progresses. Therefore, it shows that the final sample information can be completely independent from the initial seeds if a certain level of sample size is secured even if the initial seeds were selected through convenient sampling. Thus, RDS can be considered as an alternative which can improve upon both key informant sampling and ethnographic surveys, and it needs to be utilized for various cases domestically as well. PMID:26107223

  20. DOE methods for evaluating environmental and waste management samples

    Energy Technology Data Exchange (ETDEWEB)

    Goheen, S.C.; McCulloch, M.; Thomas, B.L.; Riley, R.G.; Sklarew, D.S.; Mong, G.M.; Fadeff, S.K. [eds.

    1994-10-01

    DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods) is a resource intended to support sampling and analytical activities for the evaluation of environmental and waste management samples from U.S. Department of Energy (DOE) sites. DOE Methods is the result of extensive cooperation from all DOE analytical laboratories. All of these laboratories have contributed key information and provided technical reviews as well as significant moral support leading to the success of this document. DOE Methods is designed to encompass methods for collecting representative samples and for determining the radioisotope activity and organic and inorganic composition of a sample. These determinations will aid in defining the type and breadth of contamination and thus determine the extent of environmental restoration or waste management actions needed, as defined by the DOE, the U.S. Environmental Protection Agency, or others. The development of DOE Methods is supported by the Analytical Services Division of DOE. Unique methods or methods consolidated from similar procedures in the DOE Procedures Database are selected for potential inclusion in this document. Initial selection is based largely on DOE needs and procedure applicability and completeness. Methods appearing in this document are one of two types, {open_quotes}Draft{close_quotes} or {open_quotes}Verified{close_quotes}. {open_quotes}Draft{close_quotes} methods that have been reviewed internally and show potential for eventual verification are included in this document, but they have not been reviewed externally, and their precision and bias may not be known. {open_quotes}Verified{close_quotes} methods in DOE Methods have been reviewed by volunteers from various DOE sites and private corporations. These methods have delineated measures of precision and accuracy.

  1. DOE methods for evaluating environmental and waste management samples

    International Nuclear Information System (INIS)

    DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods) is a resource intended to support sampling and analytical activities for the evaluation of environmental and waste management samples from U.S. Department of Energy (DOE) sites. DOE Methods is the result of extensive cooperation from all DOE analytical laboratories. All of these laboratories have contributed key information and provided technical reviews as well as significant moral support leading to the success of this document. DOE Methods is designed to encompass methods for collecting representative samples and for determining the radioisotope activity and organic and inorganic composition of a sample. These determinations will aid in defining the type and breadth of contamination and thus determine the extent of environmental restoration or waste management actions needed, as defined by the DOE, the U.S. Environmental Protection Agency, or others. The development of DOE Methods is supported by the Analytical Services Division of DOE. Unique methods or methods consolidated from similar procedures in the DOE Procedures Database are selected for potential inclusion in this document. Initial selection is based largely on DOE needs and procedure applicability and completeness. Methods appearing in this document are one of two types, open-quotes Draftclose quotes or open-quotes Verifiedclose quotes. open-quotes Draftclose quotes methods that have been reviewed internally and show potential for eventual verification are included in this document, but they have not been reviewed externally, and their precision and bias may not be known. open-quotes Verifiedclose quotes methods in DOE Methods have been reviewed by volunteers from various DOE sites and private corporations. These methods have delineated measures of precision and accuracy

  2. Soil separator and sampler and method of sampling

    Science.gov (United States)

    O'Brien, Barry H [Idaho Falls, ID; Ritter, Paul D [Idaho Falls, ID

    2010-02-16

    A soil sampler includes a fluidized bed for receiving a soil sample. The fluidized bed may be in communication with a vacuum for drawing air through the fluidized bed and suspending particulate matter of the soil sample in the air. In a method of sampling, the air may be drawn across a filter, separating the particulate matter. Optionally, a baffle or a cyclone may be included within the fluidized bed for disentrainment, or dedusting, so only the finest particulate matter, including asbestos, will be trapped on the filter. The filter may be removable, and may be tested to determine the content of asbestos and other hazardous particulate matter in the soil sample.

  3. Sci—Sat AM: Stereo — 05: The Development of Quality Assurance Methods for Trajectory based Cranial SRS Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, B; Duzenli, C; Gete, E [BC Cancer Agency, Vancouver Cancer Centre (Canada); Teke, T [BC Cancer Agency, Centre for the Southern Interior (Canada)

    2014-08-15

    The goal of this work was to develop and validate non-planar linac beam trajectories defined by the dynamic motion of the gantry, couch, jaws, collimator and MLCs. This was conducted on the Varian TrueBeam linac by taking advantage of the linac's advanced control features in a non-clinical mode (termed developers mode). In this work, we present quality assurance methods that we have developed to test for the positional and temporal accuracy of the linac's moving components. The first QA method focuses on the coordination of couch and gantry. For this test, we developed a cylindrical phantom which has a film insert. Using this phantom we delivered a plan with dynamic motion of the couch and gantry. We found the mean absolute deviation of the entrance position from its expected value to be 0.5mm, with a standard deviation of 0.5mm. This was within the tolerances set by the machine's mechanical accuracy and the setup accuracy of the phantom. We also present an altered picket fence test which has added dynamic and simultaneous rotations of the couch and the collimator. While the test was shown to be sensitive enough to discern errors 1° and greater, we were unable to identify any errors in the coordination of the linacs collimator and couch. When operating under normal conditions, the Varian TrueBeam linac was able to pass both tests and is within tolerances acceptable for complex trajectory based treatments.

  4. Sci—Sat AM: Stereo — 05: The Development of Quality Assurance Methods for Trajectory based Cranial SRS Treatments

    International Nuclear Information System (INIS)

    The goal of this work was to develop and validate non-planar linac beam trajectories defined by the dynamic motion of the gantry, couch, jaws, collimator and MLCs. This was conducted on the Varian TrueBeam linac by taking advantage of the linac's advanced control features in a non-clinical mode (termed developers mode). In this work, we present quality assurance methods that we have developed to test for the positional and temporal accuracy of the linac's moving components. The first QA method focuses on the coordination of couch and gantry. For this test, we developed a cylindrical phantom which has a film insert. Using this phantom we delivered a plan with dynamic motion of the couch and gantry. We found the mean absolute deviation of the entrance position from its expected value to be 0.5mm, with a standard deviation of 0.5mm. This was within the tolerances set by the machine's mechanical accuracy and the setup accuracy of the phantom. We also present an altered picket fence test which has added dynamic and simultaneous rotations of the couch and the collimator. While the test was shown to be sensitive enough to discern errors 1° and greater, we were unable to identify any errors in the coordination of the linacs collimator and couch. When operating under normal conditions, the Varian TrueBeam linac was able to pass both tests and is within tolerances acceptable for complex trajectory based treatments

  5. Precision and relative efficiency of sampling methods in teak

    Directory of Open Access Journals (Sweden)

    Dirceu Lucio Carneiro Miranda

    2015-09-01

    Full Text Available This study aimed to compare three sampling methods: fixed area, Bitterlich, and Prodan, regarding accuracy and relative efficiency to estimate the variables: diameter at 1.30 m above soil level (DBH, number of trees, basal area, and volume. The limit of error established was 10% at probability level of 95%, using 30 plots for each method. Circumference at 1.30 m above soil level was measured, for conversion in DBH, with total time counted since the plots installation until the last tree measured. The most accurate sampling was the fixed area method, for estimation of DBH and number of trees per hectare, whereas the Bitterlich method was the most accurate for estimation of basal area and volume. Bitterlich method proved to be more efficient for estimation of all variables. It can be concluded that the accuracy is not directly associated with relative efficiency, and that less usual sampling.

  6. Validation of a treatment plan-based calibration method for 2D detectors used for treatment delivery quality assurance

    International Nuclear Information System (INIS)

    Purpose: Dosimetry using film, CR, electronic portal imaging, or other 2D detectors requires calibration of the raw image data to obtain dose. Typically, a series of known doses are given to the detector, the raw signal for each dose is obtained, and a calibration curve is created. This calibration curve is then applied to the measured raw signals to convert them to dose. With the advent of IMRT, film dosimetry for quality assurance has become a routine and labor intensive part of the physicist's day. The process of calibrating the film or other 2D detector takes time and additional film or images for performing the calibration, and comes with its own source of errors. This article studies a new methodology for the relative dose calibration of 2D imaging detectors especially useful for IMRT QA, which relies on the treatment plan dose image to provide the dose information which is paired with the raw QA image data after registration of the two images (plan-based calibration). Methods: Validation of the accuracy and robustness of the method is performed on ten IMRT cases performed using EDR2 film with conventional and plan-based calibration. Also, for each of the ten cases, a 5 mm registration error was introduced and the Gamma analysis was reevaluated. In addition, synthetic image tests were performed to test the limits of the method. The Gamma analysis is used as a measure of dosimetric agreement between plan and film for the clinical cases and a dose difference metric for the synthetic cases. Results: The QA image calibrated by the plan-based method was found to more accurately match the treatment plan doses than the conventionally calibrated films and also to reveal dose errors more effectively when a registration error was introduced. When synthetic acquired images were systematically studied, localized and randomly placed dose errors were correctly identified without excessive falsely passing or falsely failing pixels, unless the errors were concentrated in a

  7. Towards improvement in quality assurance

    International Nuclear Information System (INIS)

    This first document in the series of the International Nuclear Safety Advisory Group (INSAG) Technical Notes is a general guideline for the establishment of effective quality assurance procedures at nuclear facilities. It sets out primary requirements such as quality objectives, methods for measuring the effectiveness of the quality assurance programme, priority of activities in relation to importance of safety of items, motivation of personnel

  8. Using re-sampling methods in mortality studies.

    Directory of Open Access Journals (Sweden)

    Igor Itskovich

    Full Text Available Traditional methods of computing standardized mortality ratios (SMR in mortality studies rely upon a number of conventional statistical propositions to estimate confidence intervals for obtained values. Those propositions include a common but arbitrary choice of the confidence level and the assumption that observed number of deaths in the test sample is a purely random quantity. The latter assumption may not be fully justified for a series of periodic "overlapping" studies. We propose a new approach to evaluating the SMR, along with its confidence interval, based on a simple re-sampling technique. The proposed method is most straightforward and requires neither the use of above assumptions nor any rigorous technique, employed by modern re-sampling theory, for selection of a sample set. Instead, we include all possible samples that correspond to the specified time window of the study in the re-sampling analysis. As a result, directly obtained confidence intervals for repeated overlapping studies may be tighter than those yielded by conventional methods. The proposed method is illustrated by evaluating mortality due to a hypothetical risk factor in a life insurance cohort. With this method used, the SMR values can be forecast more precisely than when using the traditional approach. As a result, the appropriate risk assessment would have smaller uncertainties.

  9. Extending the alias Monte Carlo sampling method to general distributions

    International Nuclear Information System (INIS)

    The alias method is a Monte Carlo sampling technique that offers significant advantages over more traditional methods. It equals the accuracy of table lookup and the speed of equal probable bins. The original formulation of this method sampled from discrete distributions and was easily extended to histogram distributions. We have extended the method further to applications more germane to Monte Carlo particle transport codes: continuous distributions. This paper presents the alias method as originally derived and our extensions to simple continuous distributions represented by piecewise linear functions. We also present a method to interpolate accurately between distributions tabulated at points other than the point of interest. We present timing studies that demonstrate the method's increased efficiency over table lookup and show further speedup achieved through vectorization. 6 refs., 12 figs., 2 tabs

  10. Quality assurance

    International Nuclear Information System (INIS)

    This compendium intends to give fast bibliographic information and to fill the visible gap between documentation and general bibliographic information. The reader is given an outline of quality assurance and some examples of techniques from the relevant literature. The practical engineer, who is always short of time, is thus offered a quick survey and a fast deepening of his understanding by means of literature dealing specifically with his unresolved problems. The mansucript has been kept in tis original form in order to speed up tis publication. The RKW technical department limited itself to checking its contents and the adherence to the established information goals. (orig.) 891 RW/orig. 892 MB

  11. Characteristics quality system assurance of university programs

    OpenAIRE

    Lucian Ion Medar

    2011-01-01

    Quality assurance program of study requires time, dedication, effort, innovative thinking and creativity. Competitive research programs monitored by quality assurance system to create the desired results on the relationship between learning and teaching methods and assessment.

  12. Tritium monitoring in air, optimization of a sampling method

    International Nuclear Information System (INIS)

    An air humidity sampling method using dry silica gel and its application to tritium activity concentration monitoring in air humidity are described. The method was used to monitor tritium in the surroundings of Czech nuclear power plants. The problem of elimination of cross-contamination is discussed

  13. Sampling Methods for Varroa Mites on the Domesticated Honeybee

    OpenAIRE

    Barlow, Vonny M.; Richard D. Fell

    2009-01-01

    Varroa mites are serious pests of the apiculture industry throughout the Americas. Various methods have been used to determine if a colony is infested with varroa mites necessitating some type of control. This publication presents various varroa sampling methods and compares their relative effectiveness.

  14. Heat-capacity measurements on small samples: The hybrid method

    NARCIS (Netherlands)

    J.C.P. Klaasse; E.H. Brück

    2008-01-01

    A newly developed method is presented for measuring heat capacities on small samples, particularly where thermal isolation is not sufficient for the use of the traditional semiadiabatic heat-pulse technique. This "hybrid technique" is a modification of this heat-pulse method in case the temperature

  15. Beryllium Wipe Sampling (differing methods - differing exposure potentials)

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, Kent

    2005-03-09

    This research compared three wipe sampling techniques currently used to test for beryllium contamination on room and equipment surfaces in Department of Energy facilities. Efficiencies of removal of beryllium contamination from typical painted surfaces were tested by wipe sampling without a wetting agent, with water-moistened wipe materials, and by methanol-moistened wipes. Analysis indicated that methanol-moistened wipe sampling removed about twice as much beryllium/oil-film surface contamination as water-moistened wipes, which removed about twice as much residue as dry wipes. Criteria at 10 CFR 850.30 and .31 were established on unspecified wipe sampling method(s). The results of this study reveal a need to identify criteria-setting method and equivalency factors. As facilities change wipe sampling methods among the three compared in this study, these results may be useful for approximate correlations. Accurate decontamination decision-making depends on the selection of appropriate wetting agents for the types of residues and surfaces. Evidence for beryllium sensitization via skin exposure argues in favor of wipe sampling with wetting agents that provide enhanced removal efficiency such as methanol when surface contamination includes oil mist residue.

  16. Sensitivity of gamma analysis method for the evaluation of pre-treatment quality assurance of IMRT plans using portal dosimetry

    International Nuclear Information System (INIS)

    To evaluate the sensitivity of gamma analysis method for the evaluation of pre treatment quality assurance of IMRT plans using portal dosimetry. We had generated two sets of portal dosimetry QA plans of six IMRT plans with 33 fields for varian clinic iX (6 MV photons) equipped with millennium MLC 120 and portal dosimetry, in which one set of plans calculated without changing dose and the other set of plans calculated with intentionally introduced 3% dose difference. All these plans were delivered and acquired portal image. Area gamma index were analysed with and without applied lateral shifts by 1 mm increment to portal doors with 3 mm 3% criteria as well as 2 mm 3% and 1 mm 3% criteria. Their results are tabulated and compared with generated and analysed dynalog files. Average area gamma passing rate with criteria 3 % and 3 mm, 3 % and 2 mm and 3% and 1 mm was 99.25±0.75, 96.7±0.84 and 89.8±3.1 respectively. Average area gamma passing rate of laterally shifted portal dose by 1 mm, 2 mm, 3 mm was 97.68±0.8318, 93.98±1.65 and 87.9±1.627. The compared central axis point dose of 3% error introduced predicted dose and measured dose was -1.64±1.7%. From the dynalog files the average % of counts of less than 1 mm error of mlc position at the time of beam delivery was 95.628±4.1% and more than 2 mm leaf position error was not recorded. We conclude that the Varian portal dosimetry (aS-1000) tool is very sensible tool with lesser than 3% 3 mm error. It's a very effective tool to evaluate IMRT patient specific QA with 3 mm 3% criteria. (author)

  17. Experience Sampling Methods: A Modern Idiographic Approach to Personality Research

    OpenAIRE

    Tamlin S. Conner; Tennen, Howard; Fleeson, William; Barrett, Lisa Feldman

    2009-01-01

    Experience sampling methods are essential tools for building a modern idiographic approach to understanding personality. These methods yield multiple snapshots of people’s experiences over time in daily life and allow researchers to identify patterns of behavior within a given individual, rather than strictly identify patterns of behavior across individuals, as with standard nomothetic approaches. In this article, we discuss the origin and evolution of idiographic methods in the field of pers...

  18. Sample preparation methods for determination of drugs of abuse in hair samples: A review.

    Science.gov (United States)

    Vogliardi, Susanna; Tucci, Marianna; Stocchero, Giulia; Ferrara, Santo Davide; Favretto, Donata

    2015-02-01

    Hair analysis has assumed increasing importance in the determination of substances of abuse, both in clinical and forensic toxicology investigations. Hair analysis offers particular advantages over other biological matrices (blood and urine), including a larger window of detection, ease of collection and sample stability. In the present work, an overview of sample preparation techniques for the determination of substances of abuse in hair is provided, specifically regarding the principal steps in hair sample treatment-decontamination, extraction and purification. For this purpose, a survey of publications found in the MEDLINE database from 2000 to date was conducted. The most widely consumed substances of abuse and psychotropic drugs were considered. Trends in simplification of hair sample preparation, washing procedures and cleanup methods are discussed. Alternative sample extraction techniques, such as head-space solid phase microextraction (HS-SPDE), supercritical fluid extraction (SFE) and molecularly imprinted polymers (MIP) are also reported. PMID:25604816

  19. Study on a Stratified Sampling Investigation Method for Resident Travel and the Sampling Rate

    OpenAIRE

    2015-01-01

    This text first dissected the relationship between average travel frequency, trip mode structure, and the characteristics of residential areas. The results showed that conducting a stratified resident travel investigation in accordance with the characteristics of residential areas will yield samples with much smaller differences and reduce the investigation sampling rate. Accordingly, a new type of resident travel investigation method was put forward based on the above ideas. The stratified s...

  20. Development of sample preparation method for honey analysis using PIXE

    International Nuclear Information System (INIS)

    We developed an original preparation method for honey samples (samples in paste-like state) specifically designed for PIXE analysis. The results of PIXE analysis of thin targets prepared by adding a standard containing nine elements to honey samples demonstrated that the preparation method bestowed sufficient accuracy on quantitative values. PIXE analysis of 13 kinds of honey was performed, and eight mineral components (Si, P, S, K, Ca, Mn, Cu and Zn) were detected in all honey samples. The principal mineral components were K and Ca, and the quantitative value for K accounted for the majority of the total value for mineral components. K content in honey varies greatly depending on the plant source. Chestnuts had the highest K content. In fact, it was 2-3 times that of Manuka, which is known as a high quality honey. K content of false-acacia, which is produced in the greatest abundance, was 1/20 that of chestnuts. (author)

  1. Reliability Analysis Using Dimension Reduction Method with Variable Sampling Points

    International Nuclear Information System (INIS)

    This study provides how the Dimension Reduction (DR) method as an efficient technique for reliability analysis can acquire its increased efficiency when it is applied to highly nonlinear problems. In the highly nonlinear engineering systems, 4N+1 (N: number of random variables) sampling is generally recognized to be appropriate. However, there exists uncertainty concerning the standard for judgment of non-linearity of the system as well as possibility of diverse degrees of non-linearity according to each of the random variables. In this regard, this study judged the linearity individually on each random variable after 2N+1 sampling. If high non-linearity appeared, 2 additional sampling was administered on each random variable to apply the DR method. The applications of the proposed sampling to the examples produced the constant results with increased efficiency

  2. Marshall Island radioassay quality assurance program an overview

    Energy Technology Data Exchange (ETDEWEB)

    Conrado, C.L.; Hamilton, T.F.; Kehl, S.R.; Robison, W.L.; Stoker, A.C.

    1998-09-01

    The Lawrence Livermore National Laboratory has developed an extensive quality assurance program to provide high quality data and assessments in support of the Marshall Islands Dose Assessment and Radioecology Program. Our quality assurance objectives begin with the premise of providing integrated and cost-effective program support (to meet wide-ranging programmatic needs, scientific peer review, litigation defense, and build public confidence) and continue through from design and implementation of large-scale field programs, sampling and sample preparation, radiometric and chemical analyses, documentation of quality assurance/quality control practices, exposure assessments, and dose/risk assessments until publication. The basic structure of our radioassay quality assurance/quality control program can be divided into four essential elements; (1) sample and data integrity control; (2) instrument validation and calibration; (3) method performance testing, validation, development and documentation; and (4) periodic peer review and on-site assessments. While our quality assurance objectives are tailored towards a single research program and the evaluation of major exposure pathways/critical radionuclides pertinent to the Marshall Islands, we have attempted to develop quality assurance practices that are consistent with proposed criteria designed for laboratory accre

  3. Sampling and sample preparation methods for the analysis of trace elements in biological material

    International Nuclear Information System (INIS)

    The authors attempt to give a most systamtic possible treatment of the sample taking and sample preparation of biological material (particularly in human medicine) for trace analysis (e.g. neutron activation analysis, atomic absorption spectrometry). Contamination and loss problems are discussed as well as the manifold problems of the different consistency of solid and liquid biological materials, as well as the stabilization of the sample material. The process of dry and wet ashing is particularly dealt with, where new methods are also described. (RB)

  4. An algorithm to improve sampling efficiency for uncertainty propagation using sampling based method

    Energy Technology Data Exchange (ETDEWEB)

    Campolina, Daniel; Lima, Paulo Rubens I., E-mail: campolina@cdtn.br, E-mail: pauloinacio@cpejr.com.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Tecnologia de Reatores; Pereira, Claubia; Veloso, Maria Auxiliadora F., E-mail: claubia@nuclear.ufmg.br, E-mail: dora@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2015-07-01

    Sample size and computational uncertainty were varied in order to investigate sample efficiency and convergence of the sampling based method for uncertainty propagation. Transport code MCNPX was used to simulate a LWR model and allow the mapping, from uncertain inputs of the benchmark experiment, to uncertain outputs. Random sampling efficiency was improved through the use of an algorithm for selecting distributions. Mean range, standard deviation range and skewness were verified in order to obtain a better representation of uncertainty figures. Standard deviation of 5 pcm in the propagated uncertainties for 10 n-samples replicates was adopted as convergence criterion to the method. Estimation of 75 pcm uncertainty on reactor k{sub eff} was accomplished by using sample of size 93 and computational uncertainty of 28 pcm to propagate 1σ uncertainty of burnable poison radius. For a fixed computational time, in order to reduce the variance of the uncertainty propagated, it was found, for the example under investigation, it is preferable double the sample size than double the amount of particles followed by Monte Carlo process in MCNPX code. (author)

  5. An algorithm to improve sampling efficiency for uncertainty propagation using sampling based method

    International Nuclear Information System (INIS)

    Sample size and computational uncertainty were varied in order to investigate sample efficiency and convergence of the sampling based method for uncertainty propagation. Transport code MCNPX was used to simulate a LWR model and allow the mapping, from uncertain inputs of the benchmark experiment, to uncertain outputs. Random sampling efficiency was improved through the use of an algorithm for selecting distributions. Mean range, standard deviation range and skewness were verified in order to obtain a better representation of uncertainty figures. Standard deviation of 5 pcm in the propagated uncertainties for 10 n-samples replicates was adopted as convergence criterion to the method. Estimation of 75 pcm uncertainty on reactor keff was accomplished by using sample of size 93 and computational uncertainty of 28 pcm to propagate 1σ uncertainty of burnable poison radius. For a fixed computational time, in order to reduce the variance of the uncertainty propagated, it was found, for the example under investigation, it is preferable double the sample size than double the amount of particles followed by Monte Carlo process in MCNPX code. (author)

  6. Fluidics platform and method for sample preparation and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Benner, W. Henry; Dzenitis, John M.; Bennet, William J.; Baker, Brian R.

    2014-08-19

    Herein provided are fluidics platform and method for sample preparation and analysis. The fluidics platform is capable of analyzing DNA from blood samples using amplification assays such as polymerase-chain-reaction assays and loop-mediated-isothermal-amplification assays. The fluidics platform can also be used for other types of assays and analyzes. In some embodiments, a sample in a sealed tube can be inserted directly. The following isolation, detection, and analyzes can be performed without a user's intervention. The disclosed platform may also comprises a sample preparation system with a magnetic actuator, a heater, and an air-drying mechanism, and fluid manipulation processes for extraction, washing, elution, assay assembly, assay detection, and cleaning after reactions and between samples.

  7. Self-contained cryogenic gas sampling apparatus and method

    Science.gov (United States)

    McManus, G.J.; Motes, B.G.; Bird, S.K.; Kotter, D.K.

    1996-03-26

    Apparatus for obtaining a whole gas sample, is composed of: a sample vessel having an inlet for receiving a gas sample; a controllable valve mounted for controllably opening and closing the inlet; a valve control coupled to the valve for opening and closing the valve at selected times; a portable power source connected for supplying operating power to the valve control; and a cryogenic coolant in thermal communication with the vessel for cooling the interior of the vessel to cryogenic temperatures. A method is described for obtaining an air sample using the apparatus described above, by: placing the apparatus at a location at which the sample is to be obtained; operating the valve control to open the valve at a selected time and close the valve at a selected subsequent time; and between the selected times maintaining the vessel at a cryogenic temperature by heat exchange with the coolant. 3 figs.

  8. Computing Greeks with Multilevel Monte Carlo Methods using Importance Sampling

    OpenAIRE

    Euget, Thomas

    2012-01-01

    This paper presents a new efficient way to reduce the variance of an estimator of popular payoffs and greeks encounter in financial mathematics. The idea is to apply Importance Sampling with the Multilevel Monte Carlo recently introduced by M.B. Giles. So far, Importance Sampling was proved successful in combination with standard Monte Carlo method. We will show efficiency of our approach on the estimation of financial derivatives prices and then on the estimation of Greeks (i.e. sensitivitie...

  9. Characterizing lentic freshwater fish assemblages using multiple sampling methods

    Science.gov (United States)

    Fischer, Jesse R.; Quist, Michael

    2014-01-01

    Characterizing fish assemblages in lentic ecosystems is difficult, and multiple sampling methods are almost always necessary to gain reliable estimates of indices such as species richness. However, most research focused on lentic fish sampling methodology has targeted recreationally important species, and little to no information is available regarding the influence of multiple methods and timing (i.e., temporal variation) on characterizing entire fish assemblages. Therefore, six lakes and impoundments (48–1,557 ha surface area) were sampled seasonally with seven gear types to evaluate the combined influence of sampling methods and timing on the number of species and individuals sampled. Probabilities of detection for species indicated strong selectivities and seasonal trends that provide guidance on optimal seasons to use gears when targeting multiple species. The evaluation of species richness and number of individuals sampled using multiple gear combinations demonstrated that appreciable benefits over relatively few gears (e.g., to four) used in optimal seasons were not present. Specifically, over 90 % of the species encountered with all gear types and season combinations (N = 19) from six lakes and reservoirs were sampled with nighttime boat electrofishing in the fall and benthic trawling, modified-fyke, and mini-fyke netting during the summer. Our results indicated that the characterization of lentic fish assemblages was highly influenced by the selection of sampling gears and seasons, but did not appear to be influenced by waterbody type (i.e., natural lake, impoundment). The standardization of data collected with multiple methods and seasons to account for bias is imperative to monitoring of lentic ecosystems and will provide researchers with increased reliability in their interpretations and decisions made using information on lentic fish assemblages.

  10. Compressive sampling in computed tomography: Method and application

    International Nuclear Information System (INIS)

    Since Donoho and Candes et al. published their groundbreaking work on compressive sampling or compressive sensing (CS), CS theory has attracted a lot of attention and become a hot topic, especially in biomedical imaging. Specifically, some CS based methods have been developed to enable accurate reconstruction from sparse data in computed tomography (CT) imaging. In this paper, we will review the progress in CS based CT from aspects of three fundamental requirements of CS: sparse representation, incoherent sampling and reconstruction algorithm. In addition, some potential applications of compressive sampling in CT are introduced

  11. Compressive sampling in computed tomography: Method and application

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Zhanli [Paul Lauterbur Center for Biomedical Imaging Research, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen (China); Beijing Center for Mathematics and Information Interdisciplinary Sciences, Beijing (China); Shenzhen Key Lab for Molecular Imaging, Shenzhen (China); Liang, Dong, E-mail: dong.liang@siat.ac.cn [Paul Lauterbur Center for Biomedical Imaging Research, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen (China); Beijing Center for Mathematics and Information Interdisciplinary Sciences, Beijing (China); Xia, Dan [University of Pennsylvania, Philadelphia (United States); Zheng, Hairong [Paul Lauterbur Center for Biomedical Imaging Research, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen (China); Beijing Center for Mathematics and Information Interdisciplinary Sciences, Beijing (China)

    2014-06-01

    Since Donoho and Candes et al. published their groundbreaking work on compressive sampling or compressive sensing (CS), CS theory has attracted a lot of attention and become a hot topic, especially in biomedical imaging. Specifically, some CS based methods have been developed to enable accurate reconstruction from sparse data in computed tomography (CT) imaging. In this paper, we will review the progress in CS based CT from aspects of three fundamental requirements of CS: sparse representation, incoherent sampling and reconstruction algorithm. In addition, some potential applications of compressive sampling in CT are introduced.

  12. Introduction to Monte Carlo methods: sampling techniques and random numbers

    International Nuclear Information System (INIS)

    The Monte Carlo method describes a very broad area of science, in which many processes, physical systems and phenomena that are statistical in nature and are difficult to solve analytically are simulated by statistical methods employing random numbers. The general idea of Monte Carlo analysis is to create a model, which is similar as possible to the real physical system of interest, and to create interactions within that system based on known probabilities of occurrence, with random sampling of the probability density functions. As the number of individual events (called histories) is increased, the quality of the reported average behavior of the system improves, meaning that the statistical uncertainty decreases. Assuming that the behavior of physical system can be described by probability density functions, then the Monte Carlo simulation can proceed by sampling from these probability density functions, which necessitates a fast and effective way to generate random numbers uniformly distributed on the interval (0,1). Particles are generated within the source region and are transported by sampling from probability density functions through the scattering media until they are absorbed or escaped the volume of interest. The outcomes of these random samplings or trials, must be accumulated or tallied in an appropriate manner to produce the desired result, but the essential characteristic of Monte Carlo is the use of random sampling techniques to arrive at a solution of the physical problem. The major components of Monte Carlo methods for random sampling for a given event are described in the paper

  13. Methods for Sampling and Measurement of Compressed Air Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Stroem, L.

    1976-10-15

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

  14. Noninvasive methods for estradiol recovery from infant fecal samples

    Directory of Open Access Journals (Sweden)

    AmandaL Thompson

    2010-11-01

    Full Text Available While the activation of the infant hypothalamic-pituitary-gonadal (HPG axis and the existence of a postnatal gonadotrophin surge were first documented in the early 1970s, study of the longitudinal development of gonadal hormones in infancy, and the potential physiological and behavioral correlates of this development, have been hampered by reliance on infrequent serum sampling. The present study reports the validation of a noninvasive method for repeated assessment of steroid hormones in infant fecal samples. Fecal samples were collected in, and excised from cotton diaper liners, and extracted using methanol. Extracts were analyzed for estradiol using a diluted assay modification. Method validity was supported by a steroid recovery rate of at least 80%, a sensitivity of 0.35 pg/ml, and inter- and intra-assay coefficients of variations of less than 10% and 20%, respectively. Variation in estradiol concentration was assessed across (1 sample type (scraped vs. cut from diaper liner, (2 time of day (morning vs. afternoon/evening samples, (3 time interval between samples and (4 time to assay (1 day vs. 489 days after collection. Of these characteristics, only the time interval between samples within an individual was significantly associated with estradiol concentration. This is the first report of human infant fecal estradiol levels. The results support fecal recovery as a novel and powerful noninvasive tool for longitudinal studies of human infants, expanding research opportunities for investigating development of sex-specific behaviors in infancy, and the potential effects of endocrine disruptors on development.

  15. Methods for Sampling and Measurement of Compressed Air Contaminants

    International Nuclear Information System (INIS)

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

  16. Off-axis angular spectrum method with variable sampling interval

    Science.gov (United States)

    Kim, Yong-Hae; Byun, Chun-Won; Oh, Himchan; Pi, Jae-Eun; Choi, Ji-Hun; Kim, Gi Heon; Lee, Myung-Lae; Ryu, Hojun; Hwang, Chi-Sun

    2015-08-01

    We proposed a novel off-axis angular spectrum method (ASM) for simulating free space wave propagation with a large shifted destination plane. The off-axis numerical simulation took wave propagation between a parallel source and a destination plane, but a destination plane was shifted from a source plane. The shifted angular spectrum method was proposed for diffraction simulation with a shifted destination plane and satisfied the Nyquist condition for sampling by limiting a bandwidth of a propagation field to avoid an aliasing error due to under sampling. However, the effective sampling number of the shifted ASM decreased when the shifted distance of the destination plane was large which caused a numerical error in the diffraction simulation. To compensate for the decrease of an effective sampling number for the large shifted destination plane, we used a variable sampling interval in a Fourier space to maintain the same effective sampling number independent of the shifted distance of the destination plane. As a result, our proposed off-axis ASM with a variable sampling interval can produce simulation results with high accuracy for nearly every shifted distance of a destination plane when an off-axis angle is less than 75°. We compared the performances of the off-axis ASM using the Chirp Z transform and non-uniform FFT for implementing a variable spatial frequency in a Fourier space.

  17. RAPID METHOD FOR DETERMINATION OF RADIOSTRONTIUM IN EMERGENCY MILK SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.; Culligan, B.

    2008-07-17

    A new rapid separation method for radiostrontium in emergency milk samples was developed at the Savannah River Site (SRS) Environmental Bioassay Laboratory (Aiken, SC, USA) that will allow rapid separation and measurement of Sr-90 within 8 hours. The new method uses calcium phosphate precipitation, nitric acid dissolution of the precipitate to coagulate residual fat/proteins and a rapid strontium separation using Sr Resin (Eichrom Technologies, Darien, IL, USA) with vacuum-assisted flow rates. The method is much faster than previous method that use calcination or cation exchange pretreatment, has excellent chemical recovery, and effectively removes beta interferences. When a 100 ml sample aliquot is used, the method has a detection limit of 0.5 Bq/L, well below generic emergency action levels.

  18. Rapid Method For Determination Of Radiostrontium In Emergency Milk Samples

    International Nuclear Information System (INIS)

    A new rapid separation method for radiostrontium in emergency milk samples was developed at the Savannah River Site (SRS) Environmental Bioassay Laboratory (Aiken, SC, USA) that will allow rapid separation and measurement of Sr-90 within 8 hours. The new method uses calcium phosphate precipitation, nitric acid dissolution of the precipitate to coagulate residual fat/proteins and a rapid strontium separation using Sr Resin (Eichrom Technologies, Darien, IL, USA) with vacuum-assisted flow rates. The method is much faster than previous method that use calcination or cation exchange pretreatment, has excellent chemical recovery, and effectively removes beta interferences. When a 100 ml sample aliquot is used, the method has a detection limit of 0.5 Bq/L, well below generic emergency action levels.

  19. On the Exploitation of Sensitivity Derivatives for Improving Sampling Methods

    Science.gov (United States)

    Cao, Yanzhao; Hussaini, M. Yousuff; Zang, Thomas A.

    2003-01-01

    Many application codes, such as finite-element structural analyses and computational fluid dynamics codes, are capable of producing many sensitivity derivatives at a small fraction of the cost of the underlying analysis. This paper describes a simple variance reduction method that exploits such inexpensive sensitivity derivatives to increase the accuracy of sampling methods. Three examples, including a finite-element structural analysis of an aircraft wing, are provided that illustrate an order of magnitude improvement in accuracy for both Monte Carlo and stratified sampling schemes.

  20. Method of determining an electrical property of a test sample

    DEFF Research Database (Denmark)

    2010-01-01

    A method of obtaining an electrical property of a test sample, comprising a non-conductive area and a conductive or semi-conductive test area, byperforming multiple measurements using a multi-point probe. The method comprising the steps of providing a magnetic field having field lines passing...... each tip, selecting one tip to be a current source positioned between conductive tips being used for determining a voltage in the test sample, performing a first measurement, moving the probe and performing a second measurement, calculating on the basis of the first and second measurement the...

  1. Evaluation of sample preservation methods for poultry manure.

    Science.gov (United States)

    Pan, J; Fadel, J G; Zhang, R; El-Mashad, H M; Ying, Y; Rumsey, T

    2009-08-01

    When poultry manure is collected but cannot be analyzed immediately, a method for storing the manure is needed to ensure accurate subsequent analyses. This study has 3 objectives: (1) to investigate effects of 4 poultry manure sample preservation methods (refrigeration, freezing, acidification, and freeze-drying) on the compositional characteristics of poultry manure; (2) to determine compositional differences in fresh manure with manure samples at 1, 2, and 3 d of accumulation under bird cages; and (3) to assess the influence of 14-d freezing storage on the composition of manure when later exposed to 25 degrees C for 7 d as compared with fresh manure. All manure samples were collected from a layer house. Analyses performed on the manure samples included total Kjeldahl nitrogen, uric acid nitrogen, ammonia nitrogen, and urea nitrogen. In experiment 1, the storage methods most similar to fresh manure, in order of preference, were freezing, freeze-drying, acidification, and refrigeration. Thoroughly mixing manure samples and compressing them to 2 to 3 mm is important for the freezing and freeze-dried samples. In general, refrigeration was found unacceptable for nitrogen analyses. A significant effect (P manure. Manure after 1, 2, and 3 d of accumulation had similar nitrogen compositions. The results from experiment 3 show that nitrogen components from fresh manure samples and thawed samples from 14 d of freezing are similar at 7 d but high variability of nitrogen compositions during intermediate times from 0 to 7 d prevents the recommendation of freezing manure for use in subsequent experiments and warrants future experimentation. In conclusion, fresh poultry manure can be frozen for accurate subsequent nitrogen compositional analyses but this same frozen manure may not be a reliable substitute for fresh manure if a subsequent experiment is performed. PMID:19590065

  2. RAPID SEPARATION METHOD FOR EMERGENCY WATER AND URINE SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.; Culligan, B.

    2008-08-27

    The Savannah River Site Environmental Bioassay Lab participated in the 2008 NRIP Emergency Response program administered by the National Institute for Standards and Technology (NIST) in May, 2008. A new rapid column separation method was used for analysis of actinides and {sup 90}Sr the NRIP 2008 emergency water and urine samples. Significant method improvements were applied to reduce analytical times. As a result, much faster analysis times were achieved, less than 3 hours for determination of {sup 90}Sr and 3-4 hours for actinides. This represents a 25%-33% improvement in analysis times from NRIP 2007 and a {approx}100% improvement compared to NRIP 2006 report times. Column flow rates were increased by a factor of two, with no significant adverse impact on the method performance. Larger sample aliquots, shorter count times, faster cerium fluoride microprecipitation and streamlined calcium phosphate precipitation were also employed. Based on initial feedback from NIST, the SRS Environmental Bioassay Lab had the most rapid analysis times for actinides and {sup 90}Sr analyses for NRIP 2008 emergency urine samples. High levels of potential matrix interferences may be present in emergency samples and rugged methods are essential. Extremely high levels of {sup 210}Po were found to have an adverse effect on the uranium results for the NRIP-08 urine samples, while uranium results for NRIP-08 water samples were not affected. This problem, which was not observed for NRIP-06 or NRIP-07 urine samples, was resolved by using an enhanced {sup 210}Po removal step, which will be described.

  3. Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

    Science.gov (United States)

    Schindler, Matthias; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

    2016-05-01

    Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO2 and reduced to graphite to determine 14C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

  4. Simplified CFC sampling method and spreadsheet based CFC data evaluation

    International Nuclear Information System (INIS)

    Several sampling methods exist to collect groundwater samples for CFC analysis. The established methods like sealing water samples in glass ampoules, using field-crimped copper tubes or taking large volume samples in glass bottles have some drawbacks when intended to be applied worldwide at remote locations without special trained staff. After establishment of a CFC analysis facility at IAEA, efforts were undertaken to develop a more robust and simple technique for CFC sampling. The method developed at IAEA uses commercial 50 ml glass bottles with plastic caps. In order to prevent the sample contamination via CFCs absorbed in the plastic cap, a round metal foil liner of laboratory grade aluminum is placed into the inside of the plastic cap. After extensive flushing of both bottle and cap with sample water in a metal container, the bottle is sealed under water with the cap. The glass bottle and the metal-foil liner provide a gas-tight sealing suitable for sample storage of more than one year. Essential for a successful sampling is the absence of any visible air bubble in the bottle directly after sampling, which of course can be easily checked. The method facilitates the strongly recommended custom to take multiple samples at each sampling site, being cheap and using small sized samples. Altogether five different sampling techniques with several variations were tested during a field experiment at a remote site at the Reichenkar glacier mound in the Oetztal region, Western Alps, Austria. The suitability of the sampling method described above was verified by those results and was further on extensively tested with CFC free water stored for extended time periods before analysis. For easy evaluation of measured CFC data it was desired to have available a suitable spreadsheet program. QCFC ('Quick-CFC') is an easy-to-use interactive Excel spreadsheet program for carrying out quick calculations in hydrologic studies using chlorofluorocarbons as time-dependent tracers

  5. Methods for Characterisation of unknown Suspect Radioactive Samples

    International Nuclear Information System (INIS)

    Full text: The paper presents various identification and measurement methods, used for the expertise of a wide variety of suspect radioactive materials, whose circulation was not legally stated. The main types of examined samples were: radioactive sources, illegally trafficked; suspect radioactive materials or radioactively contaminated devices; uranium tablets; fire detectors containing 241Am sources; osmium samples containing radioactive 185Os or enriched 187Os. The types of analyses and determination methods were as follows: the chemical composition was determined by using identification reagents or by neutron activation analysis; the radionuclide composition was determined by using gamma-ray spectrometry; the activity and particle emission rates were determined by using calibrated radiometric equipment; the absorbed dose rate at the wall of all types of containers and samples was determined by using calibrated dose ratemeters. The radiation exposure risk for population, due to these radioactive materials, was evaluated for every case. (author)

  6. Sampling and analysis methods for geothermal fluids and gases

    Energy Technology Data Exchange (ETDEWEB)

    Shannon, D. W.

    1978-01-01

    The data obtained for the first round robin sample collected at Mesa 6-2 wellhead, East Mesa Test Site, Imperial Valley are summarized. Test results are listed by method used for cross reference to the analytic methods section. Results obtained for radioactive isotopes present in the brine sample are tabulated. The data obtained for the second round robin sample collected from the Woolsey No. 1 first stage flash unit, San Diego Gas and Electric Niland Test Facility are presented in the same manner. Lists of the participants of the two round robins are given. Data from miscellaneous analyses are included. Summaries of values derived from the round robin raw data are presented. (MHR)

  7. FEASIBILITY OF DEVELOPING SOURCE SAMPLING METHODS FOR ASBESTOS EMISSIONS

    Science.gov (United States)

    The objective of this program was to determine the feasibility of developing methods for sampling asbestos in the emissions of major asbestos sources: (1) ore production and taconite production, (2) asbestos-cement production, (3) asbestos felt and paper production, and (4) the p...

  8. A Frequency Domain Design Method For Sampled-Data Compensators

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Jannerup, Ole Erik

    1990-01-01

    A new approach to the design of a sampled-data compensator in the frequency domain is investigated. The starting point is a continuous-time compensator for the continuous-time system which satisfy specific design criteria. The new design method will graphically show how the discrete...

  9. Apparatus and method for inspecting a surface of a sample

    NARCIS (Netherlands)

    Kruit, P.

    2014-01-01

    The invention relates to an apparatus and method for inspecting a sample. The apparatus comprises a generator for generating an array of primary charged particle beams (33), and a charged particle optical system with an optical axis (38). The optical system comprises a first lens system (37, 310) fo

  10. Global metabolite analysis of yeast: evaluation of sample preparation methods

    DEFF Research Database (Denmark)

    Villas-Bôas, Silas Granato; Højer-Pedersen, Jesper; Åkesson, Mats Fredrik;

    2005-01-01

    of intracellular metabolites, and the losses noticed during sample concentration by lyophilization and solvent evaporation. A more reliable procedure is suggested for quenching yeast cells with cold methanol solution, followed by extraction of intracellular metabolites by pure methanol. The method can be combined...

  11. MOMENT-METHOD ESTIMATION BASED ON CENSORED SAMPLE

    Institute of Scientific and Technical Information of China (English)

    NI Zhongxin; FEI Heliang

    2005-01-01

    In reliability theory and survival analysis,the problem of point estimation based on the censored sample has been discussed in many literatures.However,most of them are focused on MLE,BLUE etc;little work has been done on the moment-method estimation in censoring case.To make the method of moment estimation systematic and unifiable,in this paper,the moment-method estimators(abbr.MEs) and modified momentmethod estimators(abbr.MMEs) of the parameters based on type I and type Ⅱ censored samples are put forward involving mean residual lifetime. The strong consistency and other properties are proved. To be worth mentioning,in the exponential distribution,the proposed moment-method estimators are exactly MLEs. By a simulation study,in the view point of bias and mean square of error,we show that the MEs and MMEs are better than MLEs and the "pseudo complete sample" technique introduced in Whitten et al.(1988).And the superiority of the MEs is especially conspicuous,when the sample is heavily censored.

  12. Sample processing method for the determination of perchlorate in milk

    International Nuclear Information System (INIS)

    In recent years, many different water sources and foods have been reported to contain perchlorate. Studies indicate that significant levels of perchlorate are present in both human and dairy milk. The determination of perchlorate in milk is particularly important due to its potential health impact on infants and children. As for many other biological samples, sample preparation is more time consuming than the analysis itself. The concurrent presence of large amounts of fats, proteins, carbohydrates, etc., demands some initial cleanup; otherwise the separation column lifetime and the limit of detection are both greatly compromised. Reported milk processing methods require the addition of chemicals such as ethanol, acetic acid or acetonitrile. Reagent addition is undesirable in trace analysis. We report here an essentially reagent-free sample preparation method for the determination of perchlorate in milk. Milk samples are spiked with isotopically labeled perchlorate and centrifuged to remove lipids. The resulting liquid is placed in a disposable centrifugal ultrafilter device with a molecular weight cutoff of 10 kDa, and centrifuged. Approximately 5-10 ml of clear liquid, ready for analysis, is obtained from a 20 ml milk sample. Both bovine and human milk samples have been successfully processed and analyzed by ion chromatography-mass spectrometry (IC-MS). Standard addition experiments show good recoveries. The repeatability of the analytical result for the same sample in multiple sample cleanup runs ranged from 3 to 6% R.S.D. This processing technique has also been successfully applied for the determination of iodide and thiocyanate in milk

  13. Development of an automated data processing method for sample to sample comparison of seized methamphetamines.

    Science.gov (United States)

    Choe, Sanggil; Lee, Jaesin; Choi, Hyeyoung; Park, Yujin; Lee, Heesang; Pyo, Jaesung; Jo, Jiyeong; Park, Yonghoon; Choi, Hwakyung; Kim, Suncheun

    2012-11-30

    The information about the sources of supply, trafficking routes, distribution patterns and conspiracy links can be obtained from methamphetamine profiling. The precursor and synthetic method for the clandestine manufacture can be estimated from the analysis of minor impurities contained in methamphetamine. Also, the similarity between samples can be evaluated using the peaks that appear in chromatograms. In South Korea, methamphetamine was the most popular drug but the total seized amount of methamphetamine whole through the country was very small. Therefore, it would be more important to find the links between samples than the other uses of methamphetamine profiling. Many Asian countries including Japan and South Korea have been using the method developed by National Research Institute of Police Science of Japan. The method used gas chromatography-flame ionization detector (GC-FID), DB-5 column and four internal standards. It was developed to increase the amount of impurities and minimize the amount of methamphetamine. After GC-FID analysis, the raw data have to be processed. The data processing steps are very complex and require a lot of time and effort. In this study, Microsoft Visual Basic Application (VBA) modules were developed to handle these data processing steps. This module collected the results from the data into an Excel file and then corrected the retention time shift and response deviation generated from the sample preparation and instruments analysis. The developed modules were tested for their performance using 10 samples from 5 different cases. The processed results were analyzed with Pearson correlation coefficient for similarity assessment and the correlation coefficient of the two samples from the same case was more than 0.99. When the modules were applied to 131 seized methamphetamine samples, four samples from two different cases were found to have the common origin and the chromatograms of the four samples were appeared visually identical

  14. SU-E-I-60: Quality Assurance Testing Methods and Customized Phantom for Magnetic Resonance Imaging and Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Song, K-H; Lee, D-W; Choe, B-Y [Department of Biomedical Engineering, Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: The objectives of this study are to develop an magnetic resonance imaging and spectroscopy (MRI-MRS) fused phantom along with the inserts for metabolite quantification and to conduct quantitative analysis and evaluation of the layered vials of brain-mimicking solution for quality assurance (QA) performance, according to the localization sequence. Methods: The outer cylindrical phantom body is made of acrylic materials. The section other than where the inner vials are located was filled with copper sulfate and diluted with water so as to reduce the T1 relaxation time. Sodium chloride was included to provide conductivity similar to the human body. All measurements of MRI and MRS were made using a 3.0 T scanner (Achiva Tx 3.0 T; Philips Medical Systems, Netherlands). The MRI scan parameters were as follows: (1) spin echo (SE) T1-weighted image: repetition time (TR), 500ms; echo time (TE), 20ms; matrix, 256×256; field of view (FOV), 250mm; gap, 1mm; number of signal averages (NSA), 1; (2) SE T2-weighted image: TR, 2,500 ms; TE, 80 ms; matrix, 256×256; FOV, 250mm; gap, 1mm; NSA, 1; 23 slice images were obtained with slice thickness of 5mm. The water signal of each volume of interest was suppressed by variable pulse power and optimized relaxation delays (VAPOR) applied before the scan. By applying a point-resolved spectroscopy sequence, the MRS scan parameters were as follows: voxel size, 0.8×0.8×0.8 cm{sup 3}; TR, 2,000ms; TE, 35ms; NSA, 128. Results: Using the fused phantom, the results of measuring MRI factors were: geometric distortion, <2% and ±2 mm; image intensity uniformity, 83.09±1.33%; percent-signal ghosting, 0.025±0.004; low-contrast object detectability, 27.85±0.80. In addition, the signal-to-noise ratio of N-acetyl-aspartate was consistently high (42.00±5.66). Conclusion: The MRI-MRS QA factors obtained simultaneously using the phantom can facilitate evaluation of both images and spectra, and provide guidelines for obtaining MRI and MRS QA

  15. Do Too Many Rights Make a Wrong? A Qualitative Study of the Experiences of a Sample of Malaysian and Singapore Private Higher Education Providers in Transnational Quality Assurance

    Science.gov (United States)

    Lim, Fion Choon Boey

    2010-01-01

    Assuring the quality of transnational education has been an endeavour of increasing importance in the internationalisation of higher education but is also increasingly challenging given the involvement of many stakeholders. This paper focuses on the experiences of and challenges faced by private tertiary education providers in Malaysia and…

  16. Comparison of DNA preservation methods for environmental bacterial community samples

    Science.gov (United States)

    Gray, Michael A.; Pratte, Zoe A.; Kellogg, Christina A.

    2013-01-01

    Field collections of environmental samples, for example corals, for molecular microbial analyses present distinct challenges. The lack of laboratory facilities in remote locations is common, and preservation of microbial community DNA for later study is critical. A particular challenge is keeping samples frozen in transit. Five nucleic acid preservation methods that do not require cold storage were compared for effectiveness over time and ease of use. Mixed microbial communities of known composition were created and preserved by DNAgard™, RNAlater®, DMSO–EDTA–salt (DESS), FTA® cards, and FTA Elute® cards. Automated ribosomal intergenic spacer analysis and clone libraries were used to detect specific changes in the faux communities over weeks and months of storage. A previously known bias in FTA® cards that results in lower recovery of pure cultures of Gram-positive bacteria was also detected in mixed community samples. There appears to be a uniform bias across all five preservation methods against microorganisms with high G + C DNA. Overall, the liquid-based preservatives (DNAgard™, RNAlater®, and DESS) outperformed the card-based methods. No single liquid method clearly outperformed the others, leaving method choice to be based on experimental design, field facilities, shipping constraints, and allowable cost.

  17. Specific methods for theophylline assay in biological samples

    International Nuclear Information System (INIS)

    The objective of monitoring theophylline plasma levels in in therapeutic work is well established, and the consequences of using unspecific analytical methods are obvious. For the determination of pharmacokinetic parameters, concentrations far below the therapeutic range must often be measured. Interferences acceptable in therapeutic monitoring of theophylline could cause severe inaccuracy at these drug levels. The term specificity and its meaning are discussed in general and in relation to the different steps of the analytical procedure (e.g., sampling and sample work-up). Different analytical methods for theophylline are discussed in terms of specificity. Plasma concentrations of paraxanthine (1,7-dimethylxanthine) - a metabolite of caffeine - as high as 3 μg/ml have been observed, and the compound can interfere in various theophylline assay methods. An example is given of the pharmacokinetic consequences. (author)

  18. Comparison of aquatic macroinvertebrate samples collected using different field methods

    Science.gov (United States)

    Lenz, Bernard N.; Miller, Michael A.

    1996-01-01

    Government agencies, academic institutions, and volunteer monitoring groups in the State of Wisconsin collect aquatic macroinvertebrate data to assess water quality. Sampling methods differ among agencies, reflecting the differences in the sampling objectives of each agency. Lack of infor- mation about data comparability impedes data shar- ing among agencies, which can result in duplicated sampling efforts or the underutilization of avail- able information. To address these concerns, com- parisons were made of macroinvertebrate samples collected from wadeable streams in Wisconsin by personnel from the U.S. Geological Survey- National Water Quality Assessment Program (USGS-NAWQA), the Wisconsin Department of Natural Resources (WDNR), the U.S. Department of Agriculture-Forest Service (USDA-FS), and volunteers from the Water Action Volunteer-Water Quality Monitoring Program (WAV). This project was part of the Intergovernmental Task Force on Monitoring Water Quality (ITFM) Wisconsin Water Resources Coordination Project. The numbers, types, and environmental tolerances of the organ- isms collected were analyzed to determine if the four different field methods that were used by the different agencies and volunteer groups provide comparable results. Additionally, this study com- pared the results of samples taken from different locations and habitats within the same streams.

  19. Quality assurance of BNCT dosimetry

    International Nuclear Information System (INIS)

    using independent patient sample data. For the measurement of the absorbed doses in patients and phantoms, TL dosimeters and activation foils are used. At the moment the quality assurance of dosimetry in BNCT in Finland is according to the EU rules and planned recommendations and thus sufficient. Nevertheless microdosimetric measurement methods and gel dosimeters are planned to bring to use in addition to the dosimetric methods already utilised in order to strengthen the quality assurance (author)

  20. A flexible importance sampling method for integrating subgrid processes

    Science.gov (United States)

    Raut, E. K.; Larson, V. E.

    2016-01-01

    Numerical models of weather and climate need to compute grid-box-averaged rates of physical processes such as microphysics. These averages are computed by integrating subgrid variability over a grid box. For this reason, an important aspect of atmospheric modeling is spatial integration over subgrid scales. The needed integrals can be estimated by Monte Carlo integration. Monte Carlo integration is simple and general but requires many evaluations of the physical process rate. To reduce the number of function evaluations, this paper describes a new, flexible method of importance sampling. It divides the domain of integration into eight categories, such as the portion that contains both precipitation and cloud, or the portion that contains precipitation but no cloud. It then allows the modeler to prescribe the density of sample points within each of the eight categories. The new method is incorporated into the Subgrid Importance Latin Hypercube Sampler (SILHS). The resulting method is tested on drizzling cumulus and stratocumulus cases. In the cumulus case, the sampling error can be considerably reduced by drawing more sample points from the region of rain evaporation.

  1. New Methods of Sample Preparation for Atom Probe Specimens

    Science.gov (United States)

    Kuhlman, Kimberly, R.; Kowalczyk, Robert S.; Ward, Jennifer R.; Wishard, James L.; Martens, Richard L.; Kelly, Thomas F.

    2003-01-01

    Magnetite is a common conductive mineral found on Earth and Mars. Disk-shaped precipitates approximately 40 nm in diameter have been shown to have manganese and aluminum concentrations. Atom-probe field-ion microscopy (APFIM) is the only technique that can potentially quantify the composition of these precipitates. APFIM will be used to characterize geological and planetary materials, analyze samples of interest for geomicrobiology; and, for the metrology of nanoscale instrumentation. Prior to APFIM sample preparation was conducted by electropolishing, the method of sharp shards (MSS), or Bosch process (deep reactive ion etching) with focused ion beam (FIB) milling as a final step. However, new methods are required for difficult samples. Many materials are not easily fabricated using electropolishing, MSS, or the Bosch process, FIB milling is slow and expensive, and wet chemistry and the reactive ion etching are typically limited to Si and other semiconductors. APFIM sample preparation using the dicing saw is commonly used to section semiconductor wafers into individual devices following manufacture. The dicing saw is a time-effective method for preparing high aspect ratio posts of poorly conducting materials. Femtosecond laser micromachining is also suitable for preparation of posts. FIB time required is reduced by about a factor of 10 and multi-tip specimens can easily be fabricated using the dicing saw.

  2. The use of microbead-based spoligotyping for Mycobacterium tuberculosis complex to evaluate the quality of the conventional method: Providing guidelines for Quality Assurance when working on membranes

    Directory of Open Access Journals (Sweden)

    Garzelli Carlo

    2011-04-01

    Full Text Available Abstract Background The classical spoligotyping technique, relying on membrane reverse line-blot hybridization of the spacers of the Mycobacterium tuberculosis CRISPR locus, is used world-wide (598 references in Pubmed on April 8th, 2011. However, until now no inter-laboratory quality control study had been undertaken to validate this technique. We analyzed the quality of membrane-based spoligotyping by comparing it to the recently introduced and highly robust microbead-based spoligotyping. Nine hundred and twenty-seven isolates were analyzed totaling 39,861 data points. Samples were received from 11 international laboratories with a worldwide distribution. Methods The high-throughput microbead-based Spoligotyping was performed on CTAB and thermolyzate DNA extracted from isolated Mycobacterium tuberculosis complex (MTC strains coming from the genotyping participating centers. Information regarding how the classical Spoligotyping method was performed by center was available. Genotype discriminatory analyses were carried out by comparing the spoligotypes obtained by both methods. The non parametric U-Mann Whitney homogeneity test and the Spearman rank correlation test were performed to validate the observed results. Results Seven out of the 11 laboratories (63 %, perfectly typed more than 90% of isolates, 3 scored between 80-90% and a single center was under 80% reaching 51% concordance only. However, this was mainly due to discordance in a single spacer, likely having a non-functional probe on the membrane used. The centers using thermolyzate DNA performed as well as centers using the more extended CTAB extraction procedure. Few centers shared the same problematic spacers and these problematic spacers were scattered over the whole CRISPR locus (Mostly spacers 15, 14, 18, 37, 39, 40. Conclusions We confirm that classical spoligotyping is a robust method with generally a high reliability in most centers. The applied DNA extraction procedure (CTAB

  3. A proficiency test system to improve performance of milk analysis methods and produce reference values for component calibration samples for infrared milk analysis.

    Science.gov (United States)

    Wojciechowski, Karen L; Melilli, Caterina; Barbano, David M

    2016-08-01

    Our goal was to determine the feasibility of combining proficiency testing, analytical method quality-assurance system, and production of reference samples for calibration of infrared milk analyzers to achieve a more efficient use of resources and reduce costs while maximizing analytical accuracy within and among milk payment-testing laboratories. To achieve this, we developed and demonstrated a multilaboratory combined proficiency testing and analytical method quality-assurance system as an approach to evaluate and improve the analytical performance of methods. A set of modified milks was developed and optimized to serve multiple purposes (i.e., proficiency testing, quality-assurance and method improvement, and to provide reference materials for calibration of secondary testing methods). Over a period of years, the approach has enabled the group of laboratories to document improved analytical performance (i.e., reduced within- and between-laboratory variation) of chemical reference methods used as the primary reference for calibration of high-speed electronic milk-testing equipment. An annual meeting of the laboratory technicians allows for review of results and discussion of each method and provides a forum for communication of experience and techniques that are of value to new analysts in the group. The monthly proficiency testing sample exchanges have the added benefit of producing all-laboratory mean reference values for a set of 14 milks that can be used for calibration, evaluation, and troubleshooting of calibration adjustment issues on infrared milk analyzers. PMID:27209129

  4. The Sensitivity of Respondent-driven Sampling Method

    CERN Document Server

    Lu, Xin; Britton, Tom; Camitz, Martin; Kim, Beom Jun; Thorson, Anna; Liljeros, Fredrik

    2012-01-01

    Researchers in many scientific fields make inferences from individuals to larger groups. For many groups however, there is no list of members from which to take a random sample. Respondent-driven sampling (RDS) is a relatively new sampling methodology that circumvents this difficulty by using the social networks of the groups under study. The RDS method has been shown to provide unbiased estimates of population proportions given certain conditions. The method is now widely used in the study of HIV-related high-risk populations globally. In this paper, we test the RDS methodology by simulating RDS studies on the social networks of a large LGBT web community. The robustness of the RDS method is tested by violating, one by one, the conditions under which the method provides unbiased estimates. Results reveal that the risk of bias is large if networks are directed, or respondents choose to invite persons based on characteristics that are correlated with the study outcomes. If these two problems are absent, the RD...

  5. RAPID SEPARATION METHOD FOR ACTINIDES IN EMERGENCY SOIL SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.; Culligan, B.; Noyes, G.

    2009-11-09

    A new rapid method for the determination of actinides in soil and sediment samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used for samples up to 2 grams in emergency response situations. The actinides in soil method utilizes a rapid sodium hydroxide fusion method, a lanthanum fluoride soil matrix removal step, and a streamlined column separation process with stacked TEVA, TRU and DGA Resin cartridges. Lanthanum was separated rapidly and effectively from Am and Cm on DGA Resin. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha sources are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency soil samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinides in soil results were reported within 4-5 hours with excellent quality.

  6. A Mixed Methods Investigation of Mixed Methods Sampling Designs in Social and Health Science Research

    Science.gov (United States)

    Collins, Kathleen M. T.; Onwuegbuzie, Anthony J.; Jiao, Qun G.

    2007-01-01

    A sequential design utilizing identical samples was used to classify mixed methods studies via a two-dimensional model, wherein sampling designs were grouped according to the time orientation of each study's components and the relationship of the qualitative and quantitative samples. A quantitative analysis of 121 studies representing nine fields…

  7. Aerosol sampling methods for wide area environmental sampling (WAES). Finnish support to IAEA

    International Nuclear Information System (INIS)

    Enrichment of uranium or reprocessing of nuclear fuel are expected to produce releases of non-natural radionuclides, that are carried away in air attached in airborne particles. Wide Area Environmental Sampling (WAES)-method utilises air samplers distributed in the monitored area to detect the possible releases. For reduction of expenses, the samplers located in remote areas should be able to operate long periods of time unattended. In this work, a high-volume (flow rate 150 m3/h) air sampler with an automatic filter changing system, Hunter MKII, was developed for WAES. The sampler can collect six one-week samples until it needs to be visited for unloading the used filters and loading the new ones. The device sends real-time state-of-health information to headquarters so that longtime loss of sampling can be avoided in case of malfunction. The state-of-health data also includes indication to prevent inconspicuous tampering of the unattended sampling process. Organic filter materials are used to collect particles due to their applicability to radiochemical analysis. Four filter materials were tested for collection efficiency and pressure drop. The material selected for current use (Petrianov FPP-15-1.5 used as two-layers one upon the other) can collect more than 90% of the 0.2 μm particles throughout the sampling period. If there is a large concentration of coarse particles in air (as is typically the case in desert conditions), the filter clogging rate can be significantly decreased by preceding it with a low-pressure-drop pre-filter that collects the coarse particles. The filter pressure drop is low enough to easily allow one-week sampling time in typical sampling conditions (a pre-filter may be needed in heavily dust laden desert air). (orig.)

  8. A direct method for e-cigarette aerosol sample collection.

    Science.gov (United States)

    Olmedo, Pablo; Navas-Acien, Ana; Hess, Catherine; Jarmul, Stephanie; Rule, Ana

    2016-08-01

    E-cigarette use is increasing in populations around the world. Recent evidence has shown that the aerosol produced by e-cigarettes can contain a variety of toxicants. Published studies characterizing toxicants in e-cigarette aerosol have relied on filters, impingers or sorbent tubes, which are methods that require diluting or extracting the sample in a solution during collection. We have developed a collection system that directly condenses e-cigarette aerosol samples for chemical and toxicological analyses. The collection system consists of several cut pipette tips connected with short pieces of tubing. The pipette tip-based collection system can be connected to a peristaltic pump, a vacuum pump, or directly to an e-cigarette user for the e-cigarette aerosol to flow through the system. The pipette tip-based system condenses the aerosol produced by the e-cigarette and collects a liquid sample that is ready for analysis without the need of intermediate extraction solutions. We tested a total of 20 e-cigarettes from 5 different brands commercially available in Maryland. The pipette tip-based collection system condensed between 0.23 and 0.53mL of post-vaped e-liquid after 150 puffs. The proposed method is highly adaptable, can be used during field work and in experimental settings, and allows collecting aerosol samples from a wide variety of e-cigarette devices, yielding a condensate of the likely exact substance that is being delivered to the lungs. PMID:27200479

  9. Novel sample preparation method for molecular detection of Mollicutes in cell culture samples.

    Science.gov (United States)

    Lehmann, David; Jouette, Sébastien; Olivieri, Frédéric; Laborde, Sandra; Rofel, Céline; Simon, Emmanuelle; Metz, Didier; Felden, Luc; Ribault, Sébastien

    2010-02-01

    Research laboratories, raw materials and media suppliers as well as the biopharmaceutical industry face recurrent contamination with Mollicutes. Culture-based detection methods are very slow (28 days) and could ideally be replaced by nucleic acid testing (NAT) for rapid result. These methods are nonetheless hampered by their companion sample preparation methods. They are limited by the volume tested (0.1 to 5 mL), the protein/nucleic acid content they can accommodate and are generally performed in an open environment. The processing of low volumes of complex matrices is associated to several issues such as poor representativeness, low sensitivity, inhibition and false positives. The novel sample preparation method described in this study has been developed to overcome these limitations and to process 20-mL samples containing high loads of eukaryotic cells. A dual-membrane device is coupled to magnetic bead purification. In one single and closed device, eukaryotic cells and microorganisms are separated, contaminants are concentrated, lysed and corresponding nucleic acids are collected. This novel sample preparation method has been tested with 9 different Mollicutes. The ability to detect the contaminants down to 0.6 CFU/mL by real-time PCR among hundreds of millions of CHO-S cells (Chinese hamster ovary cells, adapted to serum-free suspension culture), without biological pre-enrichment, has been demonstrated. The novel device has been compared to manual silica spin columns, which remain the gold standard in most laboratories. These columns failed to yield the same limit of detection and reproducible results without separating mammalian cells from contaminants. Co-culture experiments have shown that the novel method allows detection of Mollicutes grown for days in presence of mammalian cells, despite the fact that these microorganisms can adhere to eukaryotic cells or invade them. The co-culture data also suggest that the novel sample preparation device might improve

  10. Empirical method for matrix effects correction in liquid samples

    International Nuclear Information System (INIS)

    A simple method for the determination of Cr, Ni and Mo in stainless steels is presented. In order to minimize the matrix effects, the conditions of liquid system to dissolve stainless steels chips has been developed. Pure element solutions were used as standards. Preparation of synthetic solutions with all the elements of steel and also mathematic corrections are avoided. It results in a simple chemical operation which simplifies the method of analysis. The variance analysis of the results obtained with steel samples show that the three elements may be determined from the comparison with the analytical curves obtained with the pure elements if the same parameters in the calibration curves are used. The accuracy and the precision were checked against other techniques using the British Chemical Standards of the Bureau of Anlysed Samples Ltd. (England). (M.E.L.)

  11. A new method for vitrifying samples for cryoEM.

    Science.gov (United States)

    Razinkov, Ivan; Dandey, Venkata P; Wei, Hui; Zhang, Zhening; Melnekoff, David; Rice, William J; Wigge, Christoph; Potter, Clinton S; Carragher, Bridget

    2016-08-01

    Almost every aspect of cryo electron microscopy (cryoEM) has been automated over the last few decades. One of the challenges that remains to be addressed is the robust and reliable preparation of vitrified specimens of suitable ice thickness. We present results from a new device for preparing vitrified samples. The successful use of the device is coupled to a new "self-blotting" grid that we have developed to provide a method for spreading a sample to a thin film without the use of externally applied filter paper. This new approach has the advantage of using small amounts of protein material, resulting in large areas of ice of a well defined thickness containing evenly distributed single particles. We believe that these methods will in the future result in a system for vitrifying grids that is completely automated. PMID:27288865

  12. Method for fractional solid-waste sampling and chemical analysis

    DEFF Research Database (Denmark)

    Riber, Christian; Rodushkin, I.; Spliid, Henrik;

    2007-01-01

    Chemical characterization of solid waste is a demanding task due to the heterogeneity of the waste. This article describes how 45 material fractions hand-sorted from Danish household waste were subsampled and prepared for chemical analysis of 61 substances. All material fractions were subject to...... repeated particle-size reduction, mixing, and mass reduction until a sufficiently small but representative sample was obtained for digestion prior to chemical analysis. The waste-fraction samples were digested according to their properties for maximum recognition of all the studied substances. By combining...... four subsampling methods and five digestion methods, paying attention to the heterogeneity and the material characteristics of the waste fractions, it was possible to determine 61 substances with low detection limits, reasonable variance, and high accuracy. For most of the substances of environmental...

  13. Comparison of bioaerosol sampling methods in barns housing swine.

    OpenAIRE

    Thorne, P. S.; Kiekhaefer, M S; Whitten, P.; Donham, K J

    1992-01-01

    The air in livestock buildings contains bioaerosol levels that are sufficiently high to cause adverse health effects in animals and workers. These bioaerosols are complex mixtures of live and dead microorganisms and their products as well as other aeroallergens. The effectiveness of sampling methods used for quantifying the very high concentrations of microorganisms in these environments has not been well studied. To facilitate an accurate assessment of respiratory hazards from viable organis...

  14. Processing of Amplitudes in Ground Penetrating Radar Method : Applied Samples

    International Nuclear Information System (INIS)

    In this work, the true processing of amplitude values, which are fourth dimension (4D) in applications of 3D visualization of the ground penetrating radar (GPR) method, colorization and visualization of them are presented. The aim of the data visualization is to decompose any searched geological structure or any object from other anomalies and display successfully. The applied samples confirms how important is true amplitude processing and visualization of them

  15. Passive sampling methods for contaminated sediments: Risk assessment and management

    OpenAIRE

    Greenberg, Marc S; Chapman, Peter M.; Allan, Ian J.; Anderson, Kim A.; Apitz, Sabine E.; Beegan, Chris; Bridges, Todd S; Brown, Steve S; Cargill, John G; McCulloch, Megan C; Menzie, Charles A; Shine, James P.; Parkerton, Thomas F

    2014-01-01

    This paper details how activity-based passive sampling methods (PSMs), which provide information on bioavailability in terms of freely dissolved contaminant concentrations (C free), can be used to better inform risk management decision making at multiple points in the process of assessing and managing contaminated sediment sites. PSMs can increase certainty in site investigation and management, because C free is a better predictor of bioavailability than total bulk sediment concentration (C t...

  16. The autism inpatient collection: methods and preliminary sample description

    OpenAIRE

    Siegel, Matthew; Smith, Kahsi A.; Mazefsky, Carla; Gabriels, Robin L.; Erickson, Craig; Kaplan, Desmond; Morrow, Eric M; Wink, Logan; Santangelo, Susan L.; ,

    2015-01-01

    Background Individuals severely affected by autism spectrum disorder (ASD), including those with intellectual disability, expressive language impairment, and/or self-injurious behavior (SIB), are underrepresented in the ASD literature and extant collections of phenotypic and biological data. An understanding of ASD’s etiology and subtypes can only be as complete as the studied samples are representative. Methods The Autism Inpatient Collection (AIC) is a multi-site study enrolling children an...

  17. PURE CULTURE METHOD: GIARDIA LAMBLIA FROM DIFFERENT STOOL SAMPLES

    Directory of Open Access Journals (Sweden)

    H.A YOUSEFI

    2000-03-01

    Full Text Available Introduction. Giardiasis is one of the health problems in the world including Iran. To determine the biochemical and biological problems and also identification of various strains, it is essential to obtain pure culture and then mass production of Giardia lamblia. The goal of this study was to isolate this protozoa purely.
    Methods. Giardia lamblia cysts were isolated from 50 stool samples by use of floating of a four - layer of sucrose method. The cysts were transfered to an inducing solution. Subsequently, they were cultured in a modified culture medium (TYIS-33. Following excystation of trophozoite and its multiplication, the parasite was caltured and purified.
    Findings. Excitation of trophozoite was observed in 40 samples (80 percent from which 22 samples (55 percent yielded pure culture. The doubling time was approximately 13hr and the peak of parasite was observed between third and fourth days.
    Conclusion. The proliferation and growth rate of Giardia lamblia have enabled us to use this method widely. Cystein and ascorbic acid which are present in the induction solution, have a key role in excystation of trophozoite. Purification and passage of samples has facilitated the culture of this parasite in vitro. Therefore this method has yielded better results in comparison with other studies. This is probably due to a decrease in the amount of bovine bile or using different strains of Giardia lamblia in the present study.

  18. A direct sampling method to an inverse medium scattering problem

    KAUST Repository

    Ito, Kazufumi

    2012-01-10

    In this work we present a novel sampling method for time harmonic inverse medium scattering problems. It provides a simple tool to directly estimate the shape of the unknown scatterers (inhomogeneous media), and it is applicable even when the measured data are only available for one or two incident directions. A mathematical derivation is provided for its validation. Two- and three-dimensional numerical simulations are presented, which show that the method is accurate even with a few sets of scattered field data, computationally efficient, and very robust with respect to noises in the data. © 2012 IOP Publishing Ltd.

  19. Rock sampling. [method for controlling particle size distribution

    Science.gov (United States)

    Blum, P. (Inventor)

    1971-01-01

    A method for sampling rock and other brittle materials and for controlling resultant particle sizes is described. The method involves cutting grooves in the rock surface to provide a grouping of parallel ridges and subsequently machining the ridges to provide a powder specimen. The machining step may comprise milling, drilling, lathe cutting or the like; but a planing step is advantageous. Control of the particle size distribution is effected primarily by changing the height and width of these ridges. This control exceeds that obtainable by conventional grinding.

  20. Microextraction Methods for Preconcentration of Aluminium in Urine Samples

    Directory of Open Access Journals (Sweden)

    Farzad Farajbakhsh, Mohammad Amjadi, Jamshid Manzoori, Mohammad R. Ardalan, Abolghasem Jouyban

    2016-07-01

    Full Text Available Background: Analysis of aluminium (Al in urine samples is required in management of a number of diseases including patients with renal failure. This work aimed to present dispersive liquid-liquid microextraction (DLLME and ultrasound-assisted emulsification microextraction (USAEME methods for the preconcentration of ultra-trace amount of aluminum in human urine prior to its determination by a graphite furnace atomic absorption spectrometry (GFAAS. Methods: The microextraction methods were based on the complex formation of Al3+ with 8-hydroxyquinoline. The effect of various experimental parameters on the efficiencies of the methods and their optimum values were studied. Results: Under the optimal conditions, the limits of detection for USAEME-GFAAS and DLLME-GFAAS were 0.19 and 0.30 ng mL−1, respectively and corresponding relative standard deviations (RSD, n=5 for the determination of 40 ng mL−1 Al3+ were 5.9% and 4.9%. Conclusion: Both methods could be successfully used to the analysis of ultra trace concentrations of Al in urine samples of dialysis patients.

  1. Testing K. Patrick Method of Psychopathy Diagnosis in Russian Sample

    Directory of Open Access Journals (Sweden)

    Atadzhykova Y.A.,

    2015-12-01

    Full Text Available The article is devoted to the development of a method of diagnosing psychopathy, or antisocial (dissocial personality disorder. Modern researchers mostly use the methods of experiment, expert assessment, clinical interview or different combinations for personality disorders, including psychopathy. However, nowadays there is a growing need in development of a psychopathy diagnosis method which would be less labour-intensive, less expensive and more objective. One of the recently developed models of psychopathy is Trierarchic conceptualization by C. Patrick, it offers a new way to operationalize and diagnose psychopathy. The authors had tested this method in the Russian population, including both common sample as well as criminal offender sample consisting of individuals that have been suspected, accused or convicted of violent crimes. The subject of the current research is psychopathic traits measured by the tested method. We had carried out statistical and content analyzes of the data. Our study allowed to conclude that tested Russian version of the Triarchic Psychopathy Measure is effective enough to be used for research purposes. However, further research is required in order to render this measure valid to practical use.

  2. Creating quality assurance and international transparency for quality assurance agencies

    DEFF Research Database (Denmark)

    Lindeberg, Tobias Høygaard; Kristoffersen, Dorte

    2004-01-01

    , on the one hand, to advance internationalisation of quality assurance of higher education, and on the other hand, allow for the differences in the national approaches to quality assurance. The paper will focus on two issues: first, the strength and weaknesses of the method employed and of the use of...... the ENQA‐membership provision as a basis for the evaluative procedure; and second, the pros and cons of using mutual recognition as international evaluative procedure compared with other approaches....

  3. Sediment sampling and processing methods in Hungary, and possible improvements

    Science.gov (United States)

    Tamas, Eniko Anna; Koch, Daniel; Varga, Gyorgy

    2016-04-01

    The importance of the monitoring of sediment processes is unquestionable: sediment balance of regulated rivers suffered substantial alterations in the past century, affecting navigation, energy production, fish habitats and floodplain ecosystems alike; infiltration times to our drinking water wells have shortened, exposing them to an eventual pollution event and making them vulnerable; and sediment-attached contaminants accumulate in floodplains and reservoirs, threatening our healthy environment. The changes in flood characteristics and rating curves of our rivers are regularly being researched and described, involving state-of-the-art measurement methods, modeling tools and traditional statistics. Sediment processes however, are much less known. Unlike the investigation of flow processes, sediment-related research is scarce, which is partly due to the outdated methodology and poor database background in the specific field. Sediment-related data, information and analyses form an important and integral part of Civil engineering in relation to rivers all over the world. In relation to the second largest river of Europe, the Danube, it is widely known in expert community and for long discussed at different expert forums that the sediment balance of the river Danube has changed drastically over the past century. Sediment monitoring on the river Danube started as early as the end of the 19th century, with scattered measurements carried out. Regular sediment sampling was developed in the first half of the 20th century all along the river, with different station density and monitoring frequencies in different countries. After the first few decades of regular sampling, the concept of (mainly industrial) development changed along the river and data needs changed as well, furthermore the complicated and inexact methods of sampling bed load on the alluvial reach of the river were not developed further. Frequency of suspended sediment sampling is very low along the river

  4. Sediment sampling and processing methods in Hungary, and possible improvements

    Science.gov (United States)

    Tamas, Eniko Anna; Koch, Daniel; Varga, Gyorgy

    2016-04-01

    The importance of the monitoring of sediment processes is unquestionable: sediment balance of regulated rivers suffered substantial alterations in the past century, affecting navigation, energy production, fish habitats and floodplain ecosystems alike; infiltration times to our drinking water wells have shortened, exposing them to an eventual pollution event and making them vulnerable; and sediment-attached contaminants accumulate in floodplains and reservoirs, threatening our healthy environment. The changes in flood characteristics and rating curves of our rivers are regularly being researched and described, involving state-of-the-art measurement methods, modeling tools and traditional statistics. Sediment processes however, are much less known. Unlike the investigation of flow processes, sediment-related research is scarce, which is partly due to the outdated methodology and poor database background in the specific field. Sediment-related data, information and analyses form an important and integral part of Civil engineering in relation to rivers all over the world. In relation to the second largest river of Europe, the Danube, it is widely known in expert community and for long discussed at different expert forums that the sediment balance of the river Danube has changed drastically over the past century. Sediment monitoring on the river Danube started as early as the end of the 19th century, with scattered measurements carried out. Regular sediment sampling was developed in the first half of the 20th century all along the river, with different station density and monitoring frequencies in different countries. After the first few decades of regular sampling, the concept of (mainly industrial) development changed along the river and data needs changed as well, furthermore the complicated and inexact methods of sampling bed load on the alluvial reach of the river were not developed further. Frequency of suspended sediment sampling is very low along the river

  5. RAPID SEPARATION METHOD FOR ACTINIDES IN EMERGENCY AIR FILTER SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.; Noyes, G.; Culligan, B.

    2010-02-03

    A new rapid method for the determination of actinides and strontium in air filter samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used in emergency response situations. The actinides and strontium in air filter method utilizes a rapid acid digestion method and a streamlined column separation process with stacked TEVA, TRU and Sr Resin cartridges. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha emitters are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The purified {sup 90}Sr fractions are mounted directly on planchets and counted by gas flow proportional counting. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency air filter samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinide and {sup 90}Sr in air filter results were reported in {approx}4 hours with excellent quality.

  6. Comprehensive method to analyze thick insulating samples using PIXE technique

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, I.M., E-mail: cscientific3@aec.org.sy [Atomic Energy Commission, Department of Chemistry, P.O. Box 6091, Damascus (Syrian Arab Republic); Rihawy, M.S. [Atomic Energy Commission, Department of Chemistry, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2013-02-01

    Highlights: ► A new comprehensive method to analyze directly thick insulating samples by PIXE technique is presented. ► The method is based on the use of an electron flood gun and a beam profile monitor. ► Both accuracy and precision of the experimental procedure were successfully verified using reference material. -- Abstract: In this work, we present a new method to analyze thick insulating samples by PIXE technique. The method is based on the use of both an electron flood gun to compensate the charge build-up at the insulating surface and a beam profile monitor (BPM) to provide a precise indirect measurement of the beam current and accumulated charge. A filament extracted from an ordinary flashlight lamp was used as an electron flood gun. While, a commercial BPM has been adapted in order to carry out charge measurements. The results have revealed the convenience of using BPM for measuring the charge in PIXE measurements. The use of the electron flood gun has given very satisfactory results in term of preventing charge build-up and reducing its contribution to the bremsstrahlung background in the PIXE spectra. The applicability and efficiency of the overall system for elemental analysis were successfully verified using IAEA-Soil-7 reference material where both accuracy and precision were found to be better than 10% in most cases.

  7. Comprehensive method to analyze thick insulating samples using PIXE technique

    International Nuclear Information System (INIS)

    Highlights: ► A new comprehensive method to analyze directly thick insulating samples by PIXE technique is presented. ► The method is based on the use of an electron flood gun and a beam profile monitor. ► Both accuracy and precision of the experimental procedure were successfully verified using reference material. -- Abstract: In this work, we present a new method to analyze thick insulating samples by PIXE technique. The method is based on the use of both an electron flood gun to compensate the charge build-up at the insulating surface and a beam profile monitor (BPM) to provide a precise indirect measurement of the beam current and accumulated charge. A filament extracted from an ordinary flashlight lamp was used as an electron flood gun. While, a commercial BPM has been adapted in order to carry out charge measurements. The results have revealed the convenience of using BPM for measuring the charge in PIXE measurements. The use of the electron flood gun has given very satisfactory results in term of preventing charge build-up and reducing its contribution to the bremsstrahlung background in the PIXE spectra. The applicability and efficiency of the overall system for elemental analysis were successfully verified using IAEA-Soil-7 reference material where both accuracy and precision were found to be better than 10% in most cases

  8. A time domain sampling method for inverse acoustic scattering problems

    Science.gov (United States)

    Guo, Yukun; Hömberg, Dietmar; Hu, Guanghui; Li, Jingzhi; Liu, Hongyu

    2016-06-01

    This work concerns the inverse scattering problems of imaging unknown/inaccessible scatterers by transient acoustic near-field measurements. Based on the analysis of the migration method, we propose efficient and effective sampling schemes for imaging small and extended scatterers from knowledge of time-dependent scattered data due to incident impulsive point sources. Though the inverse scattering problems are known to be nonlinear and ill-posed, the proposed imaging algorithms are totally "direct" involving only integral calculations on the measurement surface. Theoretical justifications are presented and numerical experiments are conducted to demonstrate the effectiveness and robustness of our methods. In particular, the proposed static imaging functionals enhance the performance of the total focusing method (TFM) and the dynamic imaging functionals show analogous behavior to the time reversal inversion but without solving time-dependent wave equations.

  9. A Novel Method for Sampling Alpha-Helical Protein Backbones

    Science.gov (United States)

    Fain, Boris; Levitt, Michael

    2001-01-01

    We present a novel technique of sampling the configurations of helical proteins. Assuming knowledge of native secondary structure, we employ assembly rules gathered from a database of existing structures to enumerate the geometrically possible 3-D arrangements of the constituent helices. We produce a library of possible folds for 25 helical protein cores. In each case the method finds significant numbers of conformations close to the native structure. In addition we assign coordinates to all atoms for 4 of the 25 proteins. In the context of database driven exhaustive enumeration our method performs extremely well, yielding significant percentages of structures (0.02%--82%) within 6A of the native structure. The method's speed and efficiency make it a valuable contribution towards the goal of predicting protein structure.

  10. Radiochemistry methods in DOE methods for evaluating environmental and waste management samples

    International Nuclear Information System (INIS)

    Current standard sources of radiochemistry methods are often inappropriate for use in evaluating US Department of Energy environmental and waste management (DOE/EW) samples. Examples of current sources include EPA, ASTM, Standard Methods for the Examination of Water and Wastewater and HASL-300. Applicability of these methods is limited to specific matrices (usually water), radiation levels (usually environmental levels), and analytes (limited number). Radiochemistry methods in DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods) attempt to fill the applicability gap that exists between standard methods and those needed for DOE/EM activities. The Radiochemistry chapter in DOE Methods includes an ''analysis and reporting'' guidance section as well as radiochemistry methods. A basis for identifying the DOE/EM radiochemistry needs is discussed. Within this needs framework, the applicability of standard methods and targeted new methods is identified. Sources of new methods (consolidated methods from DOE laboratories and submissions from individuals) and the methods review process will be discussed. The processes involved in generating consolidated methods add editing individually submitted methods will be compared. DOE Methods is a living document and continues to expand by adding various kinds of methods. Radiochemistry methods are highlighted in this paper. DOE Methods is intended to be a resource for methods applicable to DOE/EM problems. Although it is intended to support DOE, the guidance and methods are not necessarily exclusive to DOE. The document is available at no cost through the Laboratory Management Division of DOE, Office of Technology Development

  11. Comparison between powder and slices diffraction methods in teeth samples

    Energy Technology Data Exchange (ETDEWEB)

    Colaco, Marcos V.; Barroso, Regina C. [Universidade do Estado do Rio de Janeiro (IF/UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada; Porto, Isabel M. [Universidade Estadual de Campinas (FOP/UNICAMP), Piracicaba, SP (Brazil). Fac. de Odontologia. Dept. de Morfologia; Gerlach, Raquel F. [Universidade de Sao Paulo (FORP/USP), Rieirao Preto, SP (Brazil). Fac. de Odontologia. Dept. de Morfologia, Estomatologia e Fisiologia; Costa, Fanny N. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LIN/COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear

    2011-07-01

    Propose different methods to obtain crystallographic information about biological materials are important since powder method is a nondestructive method. Slices are an approximation of what would be an in vivo analysis. Effects of samples preparation cause differences in scattering profiles compared with powder method. The main inorganic component of bones and teeth is a calcium phosphate mineral whose structure closely resembles hydroxyapatite (HAp). The hexagonal symmetry, however, seems to work well with the powder diffraction data, and the crystal structure of HAp is usually described in space group P63/m. Were analyzed ten third molar teeth. Five teeth were separated in enamel, detin and circumpulpal detin powder and five in slices. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the National Synchrotron Light Laboratory - LNLS, Campinas, Brazil. The LNLS synchrotron light source is composed of a 1.37 GeV electron storage ring, delivering approximately 4x10{sup -1}0 photons/s at 8 keV. A double-crystal Si(111) pre-monochromator, upstream of the beamline, was used to select a small energy bandwidth at 11 keV . Scattering signatures were obtained at intervals of 0.04 deg for angles from 24 deg to 52 deg. The human enamel experimental crystallite size obtained in this work were 30(3)nm (112 reflection) and 30(3)nm (300 reflection). These values were obtained from measurements of powdered enamel. When comparing the slice obtained 58(8)nm (112 reflection) and 37(7)nm (300 reflection) enamel diffraction patterns with those generated by the powder specimens, a few differences emerge. This work shows differences between powder and slices methods, separating characteristics of sample of the method's influence. (author)

  12. Comparison between powder and slices diffraction methods in teeth samples

    International Nuclear Information System (INIS)

    Propose different methods to obtain crystallographic information about biological materials are important since powder method is a nondestructive method. Slices are an approximation of what would be an in vivo analysis. Effects of samples preparation cause differences in scattering profiles compared with powder method. The main inorganic component of bones and teeth is a calcium phosphate mineral whose structure closely resembles hydroxyapatite (HAp). The hexagonal symmetry, however, seems to work well with the powder diffraction data, and the crystal structure of HAp is usually described in space group P63/m. Were analyzed ten third molar teeth. Five teeth were separated in enamel, detin and circumpulpal detin powder and five in slices. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the National Synchrotron Light Laboratory - LNLS, Campinas, Brazil. The LNLS synchrotron light source is composed of a 1.37 GeV electron storage ring, delivering approximately 4x10-10 photons/s at 8 keV. A double-crystal Si(111) pre-monochromator, upstream of the beamline, was used to select a small energy bandwidth at 11 keV . Scattering signatures were obtained at intervals of 0.04 deg for angles from 24 deg to 52 deg. The human enamel experimental crystallite size obtained in this work were 30(3)nm (112 reflection) and 30(3)nm (300 reflection). These values were obtained from measurements of powdered enamel. When comparing the slice obtained 58(8)nm (112 reflection) and 37(7)nm (300 reflection) enamel diffraction patterns with those generated by the powder specimens, a few differences emerge. This work shows differences between powder and slices methods, separating characteristics of sample of the method's influence. (author)

  13. Quality Assurance - Construction

    DEFF Research Database (Denmark)

    Gaarslev, Axel

    1996-01-01

    Gives contains three main chapters:1. Quality Assurance initiated by external demands2. Quality Assurance initiated by internal company goals3. Innovation strategies......Gives contains three main chapters:1. Quality Assurance initiated by external demands2. Quality Assurance initiated by internal company goals3. Innovation strategies...

  14. A direct sampling method for inverse electromagnetic medium scattering

    International Nuclear Information System (INIS)

    In this paper, we study the inverse electromagnetic medium scattering problem of estimating the support and shape of medium scatterers from scattered electric/magnetic near-field data. We shall develop a novel direct sampling method based on an analysis of electromagnetic scattering and the behavior of the fundamental solution. It is applicable to a few incident fields and needs only to compute inner products of the measured scattered field with the fundamental solutions located at sampling points. Hence, it is strictly direct, computationally very efficient and highly robust to the presence of data noise. Two- and three-dimensional numerical experiments indicate that it can provide reliable support estimates for multiple scatterers in the case of both exact and highly noisy data. (paper)

  15. A direct sampling method for inverse electromagnetic medium scattering

    KAUST Repository

    Ito, Kazufumi

    2013-09-01

    In this paper, we study the inverse electromagnetic medium scattering problem of estimating the support and shape of medium scatterers from scattered electric/magnetic near-field data. We shall develop a novel direct sampling method based on an analysis of electromagnetic scattering and the behavior of the fundamental solution. It is applicable to a few incident fields and needs only to compute inner products of the measured scattered field with the fundamental solutions located at sampling points. Hence, it is strictly direct, computationally very efficient and highly robust to the presence of data noise. Two- and three-dimensional numerical experiments indicate that it can provide reliable support estimates for multiple scatterers in the case of both exact and highly noisy data. © 2013 IOP Publishing Ltd.

  16. Chord length sampling method for analyzing stochastic distribution of fuel particles in continuous energy simulations

    International Nuclear Information System (INIS)

    Highlights: ► Accuracy of chord length sampling in continuous energy simulations is analyzed. ► Boundary effect is shown to be a major factor affecting the CLS accuracy. ► Three strategies that mitigate the boundary effect are investigated. ► The best strategy is identified and assures high confidence in the application of CLS. ► CLS can analyze the stochastic distribution of fuel particles in VHTR with high fidelity. - Abstract: The Chord Length Sampling method (CLS) is studied in continuous energy simulations by analyzing two types of Very High Temperature Gas-cooled Reactor (VHTR) unit cells: the fuel compact cell in the prismatic type VHTR and the fuel pebble cell in the pebble-bed type VHTR. Infinite multiplication factors of the unit cells are calculated by the CLS and compared to benchmark simulations at different volume packing fractions from 5% to 30%. It is shown that the accuracy of the CLS is affected by the boundary effect, which is induced by the CLS procedure itself and results in a reduction in the total volume packing fraction of the fuel particles. To mitigate the boundary effect, three correction schemes based on the research of (1) Murata et al., (2) Ji and Martin and (3) Griesheimer et al. are used to improve the accuracy by applying a corrected value of the volume packing fraction to the CLS. These corrected values are calculated based on (1) a simple linear relationship, (2) an iterative self-consistent simulation correction method and (3) a theoretically derived non-linear relationship, respectively. The CLS simulation using the corrected volume packing fraction shows excellent improvements in the infinite multiplication factors for the VHTR unit cells. Ji and Martin’s self-consistent correction method shows the best improvement

  17. Development of sampling and assay methods for WAGR radwaste

    International Nuclear Information System (INIS)

    Before radwaste can be consigned to appropriate low and intermediate level waste disposal facilities, the radioactive inventories must be assessed and adequately demonstrated. Methods for assay, and codes to calculate the inventory of weak emitters following measurement of dominant gamma emissions, have been developed for achieving such a demonstration. This report, based on studies at the Windscale Advanced Gas Cooled Reactor (WAGR) covers: (i) methods for cost-effective sampling of steel, and for assay of cobalt, nickel, niobium, silver and europium therein. (ii) investigations on activities present in WAGR graphite (iii) preliminary work on activities in WAGR concrete (iv) development of calculation codes for the estimation of radwaste total activity, given a measure of the dominant gamma radiation emissions from 60Co, applicable especially to steel radwaste. The report shows that adequate sampling and assay methods for characterising steel radwaste can be defined, and that provision can be made for these during WAGR dismantling. It has also become clear during the contract period, however, that further investigation of graphite and concrete radwaste, especially for weak beta emitters, is necessary. Provisions are being made for such investigations to continue whilst reactor dismantling is taking place

  18. Vadose Zone Sampling Methods for Detection of Preferential Pesticides Transport

    Science.gov (United States)

    Peranginangin, N.; Richards, B. K.; Steenhuis, T. S.

    2003-12-01

    Leaching of agricultural applied chemicals through the vadose zone is a major cause for the occurrence of agrichemicals in groundwater. Accurate soil water sampling methods are needed to ensure meaningful monitoring results, especially for soils that have significant preferential flow paths. The purpose of this study was to assess the capability and the effectiveness of various soil water sampling methods in detecting preferential transport of pesticides in a strongly-structured silty clay loam (Hudson series) soil. Soil water sampling devices tested were wick pan and gravity pan lysimeters, tile lines, porous ceramic cups, and pipe lysimeters; all installed at 45 to105 cm depth below the ground surface. A reasonable worse-case scenario was tested by applying a simulated rain storm soon after pesticides were sprayed at agronomic rates. Herbicides atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) and 2,4-D (2,4-dichloro-phenoxyacetic acid) were chosen as model compounds. Chloride (KCl) tracer was used to determine spatial and temporal distribution of non-reactive solute and water as well as a basis for determining the retardation in pesticides movement. Results show that observed pesticide mobility was much greater than would be predicted by uniform flow. Under relatively high soil moisture conditions, gravity and wick pan lysimeters had comparably good collection efficiencies, whereas the wick samplers had an advantage over gravity driven sampler when the soil moisture content was below field capacity. Pipe lysimeters had breakthrough patterns that were similar to pan samplers. At small plot scale, tile line samplers tended to underestimate solute concentration because of water dilution around the samplers. The use of porous cup samplers performed poorly because of their sensitivity to local profile characteristics: only by chance can they intercept and sample the preferential flow paths that are critical to transport. Wick sampler had the least

  19. Evaluation of Two Malaria Rapid Diagnostic Tests Quality Assurance (mRDT’s QA) Methods in Peripheral Health Facilities, Rural Tanzania.

    OpenAIRE

    Masanja, Irene; Maganga, Musa; Sumari, Debora; Lucchi, Naomi; Udhayakumar, Venkatachalam; McMorrow, Meredith; Kachur, Patrick

    2012-01-01

    WHO recommends confirming suspected malaria cases before initiation of treatment. Due to the imited availability of quality microscopy services, this recommendation has been followed with increased use of antigen-detecting malaria rapid diagnostic tests (mRDTs) in many malaria endemic countries. With the increased use of mRDTs, the need for a thorough mRDT quality assurance (RDT QA) method has become more apparent. One of the WHO recommendations for RDT QA is to monitor the tests in field use...

  20. Radiochemistry methods in DOE Methods for Evaluating Environmental and Waste Management Samples: Addressing new challenges

    International Nuclear Information System (INIS)

    Radiochemistry methods in Department of Energy Methods for Evaluating Environmental and Waste Management Samples (DOE Methods) add to the repertoire of other standard methods in support of U.S. Department of Energy environmental restoration and waste management (DOE/EM) radiochemical characterization activities. Current standard sources of radiochemistry methods are not always applicable for evaluating DOE/EM samples. Examples of current sources include those provided by the US Environmental Protection Agency, the American Society for Testing and Materials, Standard Methods for the Examination of Water and Wastewater, and Environmental Measurements Laboratory Procedures Manual (HASL-300). The applicability of these methods is generally limited to specific matrices (usually water), low-level radioactive samples, and a limited number of analytes. DOE Methods complements these current standard methods by addressing the complexities of EM characterization needs. The process for determining DOE/EM radiochemistry characterization needs is discussed. In this context of DOE/EM needs, the applicability of other sources of standard radiochemistry methods is defined, and gaps in methodology are identified. Current methods in DOE Methods and the EM characterization needs they address are discussed. Sources of new methods and the methods incorporation process are discussed. The means for individuals to participate in (1) identification of DOE/EM needs, (2) the methods incorporation process, and (3) submission of new methods are identified

  1. Introduction to quality assurance

    International Nuclear Information System (INIS)

    In today's interpretation 'quality assurance' means 'good management'. Quality assurance has to cover all phases of a work, but all quality assurance measures must be adapted to the relevance and complexity of the actual task. Examples are given for the preparation of quality classes, the organization of quality assurance during design and manufacturing and for auditing. Finally, efficiency and limits of quality assurance systems are described. (orig.)

  2. A microRNA isolation method from clinical samples

    Science.gov (United States)

    Zununi Vahed, Sepideh; Barzegari, Abolfazl; Rahbar Saadat, Yalda; Mohammadi, Somayeh; Samadi, Nasser

    2016-01-01

    Introduction: microRNAs (miRNAs) are considered to be novel molecular biomakers that could be exploited in the diagnosis and treatment of different diseases. The present study aimed to develop an efficient miRNA isolation method from different clinical specimens. Methods: Total RNAs were isolated by Trizol reagent followed by precipitation of the large RNAs with potassium acetate (KCH3COOH), polyethylene glycol (PEG) 4000 and 6000, and lithium chloride (LiCl). Then, small RNAs were enriched and recovered from the supernatants by applying a combination of LiCl and ethanol. The efficiency of the method was evaluated through the quality, quantity, and integrity of the recovered RNAs using the A260/280 absorbance ratio, reverse transcription PCR (RT-PCR), and quantitative real-time PCR (q-PCR). Results: Comparison of different RNA isolation methods based on the precipitation of DNA and large RNAs, high miRNA recovery and PCR efficiency revealed that applying potassium acetate with final precipitation of small RNAs using 2.5 M LiCl plus ethanol can provide high yield and quality small RNAs that can be exploited for clinical purposes. Conclusion: The current isolation method can be applied for most clinical samples including cells, formalin-fixed and paraffin-embedded (FFPE) tissues and even body fluids with a wide applicability in molecular biology investigations.

  3. New Methods for Handling Singular Sample Covariance Matrices

    CERN Document Server

    Tucci, Gabriel H

    2011-01-01

    The estimation of a covariance matrix from an insufficient amount of data is one of the most common problems in fields as diverse as multivariate statistics, wireless communications, signal processing, biology, learning theory and finance. In \\cite{MTS}, a new approach to handle singular covariance matrices was suggested. The main idea was to use dimensionality reduction in conjunction with an average over the unitary matrices. In this paper we continue with this idea and we further consider new innovative approaches that show considerable improvements with respect to traditional methods such as diagonal loading. One of the methods is called the \\emph{Ewens} estimator and uses a randomization of the sample covariance matrix over all the permutation matrices with respect to the Ewens measure. The techniques used to attack this problem are broad and run from random matrix theory to combinatorics.

  4. Alum sludge: a sampling method for the radioactivity in waters

    International Nuclear Information System (INIS)

    The alum coagulation and settling steps used in water treatment plants can be the basis of a method to concentrate radionuclides present in very small amounts in soft waters. Indeed, the gamma spectrum of a dried alum sludge shows the presence of a number of naturally occurring radionuclides, of fission and activation products unobservable unless a preconcentration step is carried out. The floc sampling technique is described. The different methods developed to relate the amount of floc to the volume of water, are presented; they are based either on the chemical characterisation of the suspended matter or on the use of internal standards like 137Cs and 7Be. The question of the distribution of some radionuclides between the liquid and the solid phases in the rivers and that of their retention by the floc is discussed: the results show clearly the importance of the suspended matter as a carrier for the radioactivity

  5. Quality assurance within regulatory bodies

    International Nuclear Information System (INIS)

    The IAEA directed extensive efforts during the years 1991 to 1995 to the integral revision of all NUSS quality assurance publications, which were approved and issued as Safety Series No.50-C/SG-Q, Quality Assurance for Safety in Nuclear Power Plants and other Nuclear Installations (1996). When these quality assurance publications were developed, their prime focus was on requirements against which work performed by the licensees could be measured and assessed by the regulatory bodies. In this way, they only helped to facilitate the functions of regulators. No requirements or recommendations were provided on how the regulators should ensure the effective implementation of their own activities. The present publication is a first attempt to collect, integrate and offer available experience to directly support performance of regulatory activities. It presents a comprehensive compilation on the application of quality assurance principles and methods by regulatory bodies to their activities. The aim is consistent good performance of regulatory activities through a systematic approach

  6. Methods to analyse the dynamics of exploited marine populations: Sampling methods

    OpenAIRE

    Farrugio, Henri

    1993-01-01

    The models used to analyse the dinamics of fish populations must be fitted to the real data using biological and demographic parameters. The data, as well as the parameters, have to be estimated from sampling strategies devised according to the specific objective. In this lecture the problems of the various sampling methods related with the particular characteristics of Mediterranean fisheries are analyzed.

  7. Software Assurance Using Structured Assurance Case Models

    OpenAIRE

    Rhodes, Thomas; Boland, Frederick; Fong, Elizabeth; Kass, Michael

    2010-01-01

    Software assurance is an important part of the software development process to reduce risks and ensure that the software is dependable and trustworthy. Software defects and weaknesses can often lead to software errors and failures and to exploitation by malicious users. Testing, certification and accreditation have been traditionally used in the software assurance process to attempt to improve software trustworthiness. In this paper, we examine a methodology known as a structured assurance mo...

  8. BMAA extraction of cyanobacteria samples: which method to choose?

    Science.gov (United States)

    Lage, Sandra; Burian, Alfred; Rasmussen, Ulla; Costa, Pedro Reis; Annadotter, Heléne; Godhe, Anna; Rydberg, Sara

    2016-01-01

    β-N-Methylamino-L-alanine (BMAA), a neurotoxin reportedly produced by cyanobacteria, diatoms and dinoflagellates, is proposed to be linked to the development of neurological diseases. BMAA has been found in aquatic and terrestrial ecosystems worldwide, both in its phytoplankton producers and in several invertebrate and vertebrate organisms that bioaccumulate it. LC-MS/MS is the most frequently used analytical technique in BMAA research due to its high selectivity, though consensus is lacking as to the best extraction method to apply. This study accordingly surveys the efficiency of three extraction methods regularly used in BMAA research to extract BMAA from cyanobacteria samples. The results obtained provide insights into possible reasons for the BMAA concentration discrepancies in previous publications. In addition and according to the method validation guidelines for analysing cyanotoxins, the TCA protein precipitation method, followed by AQC derivatization and LC-MS/MS analysis, is now validated for extracting protein-bound (after protein hydrolysis) and free BMAA from cyanobacteria matrix. BMAA biological variability was also tested through the extraction of diatom and cyanobacteria species, revealing a high variance in BMAA levels (0.0080-2.5797 μg g(-1) DW). PMID:26304815

  9. Grading of quality assurance requirements

    International Nuclear Information System (INIS)

    The present Manual provides guidance and illustrative examples for applying a method by which graded quality assurance requirements may be determined and adapted to the items and services of a nuclear power plant in conformance with the requirements of the IAEA Nuclear Safety Standards (NUSS) Code and Safety Guides on quality assurance. The Manual replaces the previous publication IAEA-TECDOC-303 on the same subject. Various methods of grading quality assurance are available in a number of Member States. During the development of the present Manual it was not considered practical to attempt to resolve the differences between those methods and it was preferred to identify and benefit from the good practices available in all the methods. The method presented in this Manual deals with the aspects of management, documentation, control, verification and administration which affect quality. 1 fig., 4 tabs

  10. Clustering Methods with Qualitative Data: a Mixed-Methods Approach for Prevention Research with Small Samples.

    Science.gov (United States)

    Henry, David; Dymnicki, Allison B; Mohatt, Nathaniel; Allen, James; Kelly, James G

    2015-10-01

    Qualitative methods potentially add depth to prevention research but can produce large amounts of complex data even with small samples. Studies conducted with culturally distinct samples often produce voluminous qualitative data but may lack sufficient sample sizes for sophisticated quantitative analysis. Currently lacking in mixed-methods research are methods allowing for more fully integrating qualitative and quantitative analysis techniques. Cluster analysis can be applied to coded qualitative data to clarify the findings of prevention studies by aiding efforts to reveal such things as the motives of participants for their actions and the reasons behind counterintuitive findings. By clustering groups of participants with similar profiles of codes in a quantitative analysis, cluster analysis can serve as a key component in mixed-methods research. This article reports two studies. In the first study, we conduct simulations to test the accuracy of cluster assignment using three different clustering methods with binary data as produced when coding qualitative interviews. Results indicated that hierarchical clustering, K-means clustering, and latent class analysis produced similar levels of accuracy with binary data and that the accuracy of these methods did not decrease with samples as small as 50. Whereas the first study explores the feasibility of using common clustering methods with binary data, the second study provides a "real-world" example using data from a qualitative study of community leadership connected with a drug abuse prevention project. We discuss the implications of this approach for conducting prevention research, especially with small samples and culturally distinct communities. PMID:25946969

  11. A sampling method for inverse scattering in the time domain

    International Nuclear Information System (INIS)

    We consider a near-field inverse scattering problem for the wave equation: find the shape of a Dirichlet scattering object from time domain measurements of scattered waves. For this time-domain inverse problem, we propose a linear sampling method, a well-known technique for corresponding frequency domain inverse scattering problems. The problem setting and the algorithm incorporate two basic features. First, the data for the method consist of measurements of causal waves, that is, of waves that vanish before some moment in time. Second, the inversion algorithm directly works on the time-domain data without using a Fourier transformation. The first point is related to the applications we have in mind, which include for instance ground-penetrating radar imaging. The second feature allows us to naturally incorporate multiple (in fact, a continuum of) frequencies in the inversion algorithm. Consequently, it offers the potential of improving the quality of the reconstruction compared to frequency domain methods working with a single frequency. We demonstrate this potential by several numerical examples

  12. A comparison of methods for representing sparsely sampled random quantities.

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Vicente Jose; Swiler, Laura Painton; Urbina, Angel; Mullins, Joshua

    2013-09-01

    This report discusses the treatment of uncertainties stemming from relatively few samples of random quantities. The importance of this topic extends beyond experimental data uncertainty to situations involving uncertainty in model calibration, validation, and prediction. With very sparse data samples it is not practical to have a goal of accurately estimating the underlying probability density function (PDF). Rather, a pragmatic goal is that the uncertainty representation should be conservative so as to bound a specified percentile range of the actual PDF, say the range between 0.025 and .975 percentiles, with reasonable reliability. A second, opposing objective is that the representation not be overly conservative; that it minimally over-estimate the desired percentile range of the actual PDF. The presence of the two opposing objectives makes the sparse-data uncertainty representation problem interesting and difficult. In this report, five uncertainty representation techniques are characterized for their performance on twenty-one test problems (over thousands of trials for each problem) according to these two opposing objectives and other performance measures. Two of the methods, statistical Tolerance Intervals and a kernel density approach specifically developed for handling sparse data, exhibit significantly better overall performance than the others.

  13. Measurement of atmospheric mercury species with manual sampling and analysis methods in a case study in Indiana

    Science.gov (United States)

    Risch, M.R.; Prestbo, E.M.; Hawkins, L.

    2007-01-01

    Ground-level concentrations of three atmospheric mercury species were measured using manual sampling and analysis to provide data for estimates of mercury dry deposition. Three monitoring stations were operated simultaneously during winter, spring, and summer 2004, adjacent to three mercury wet-deposition monitoring stations in northern, central, and southern Indiana. The monitoring locations differed in land-use setting and annual mercury-emissions level from nearby sources. A timer-controlled air-sampling system that contained a three-part sampling train was used to isolate reactive gaseous mercury, particulate-bound mercury, and elemental mercury. The sampling trains were exchanged every 6 days, and the mercury species were quantified in a laboratory. A quality-assurance study indicated the sampling trains could be held at least 120 h without a significant change in reactive gaseous or particulate-bound mercury concentrations. The manual sampling method was able to provide valid mercury concentrations in 90 to 95% of samples. Statistical differences in mercury concentrations were observed during the project. Concentrations of reactive gaseous and elemental mercury were higher in the daytime samples than in the nighttime samples. Concentrations of reactive gaseous mercury were higher in winter than in summer and were highest at the urban monitoring location. The results of this case study indicated manual sampling and analysis could be a reliable method for measurement of atmospheric mercury species and has the capability for supplying representative concentrations in an effective manner from a long-term deposition-monitoring network. ?? 2007 Springer Science+Business Media B.V.

  14. Cognitive anxiety: a method of content analysis for verbal samples.

    Science.gov (United States)

    Viney, L L; Westbrook, M T

    1976-04-01

    The work of such psychologists as Kelly, McReynolds, Epstein, and Lazarus suggested the need for a measure of cognitive anxiety and provided a definition of that construct. A method of content analysis of verbal samples was devised and found to have adequate interjudge reliability. Normative data for five groups of subjects were provided. The validity of the measure as representative of a reaction to being unable to anticipate and integrate experience meaningfully was demonstrated in (a) the higher scores of groups of subjects who were currently coping with new experiences than those who were not, (b) the significant correlation of its scores with a state rather than trait anxiety measures, (c) the variability of its scores over time as observed in a generalizeability study, and (d) the higher scores of subjects when they were dealing with experiences for which meaningful anticipation was relatively difficult. PMID:16367387

  15. Evaluation of field sampling and preservation methods for strontium-90 in ground water at the Idaho National Engineering Laboratory, Idaho

    Science.gov (United States)

    Cecil, L.D.; Knobel, L.L.; Wegner, S.J.; Moore, L.L.

    1989-01-01

    Water from four wells completed in the Snake River Plain aquifer was sampled as part of the U.S. Geological Survey 's quality assurance program to evaluate the effect of filtration and preservation methods on strontium-90 concentrations in groundwater at the Idaho National Engineering Laboratory. Water from each well was filtered through either a 0.45-micrometer membrane or a 0.1-micrometer membrane filter; unfiltered samples also were collected. Two sets of filtered and two sets of unfiltered samples was preserved in the field with reagent-grade hydrochloric acid and the other set of samples was not acidified. For water from wells with strontium-90 concentrations at or above the reporting level, 94% or more of the strontium-90 is in true solution or in colloidal particles smaller than 0.1 micrometer. These results suggest that within-laboratory reproducibility for strontium-90 in groundwater at the INEL is not significantly affected by changes in filtration and preservation methods used for sample collections. (USGS)

  16. Prevalence study of yaws in the Democratic Republic of Congo using the lot quality assurance sampling method.

    OpenAIRE

    Gerstl, S.; Kiwila, G; Dhorda, M.; Lonlas, S; Myatt, M; Ilunga, BK; Lemasson, D; Szumilin, E.; Guerin, PJ; Ferradini, L

    2009-01-01

    BACKGROUND: Until the 1970s the prevalence of non-venereal trepanomatosis, including yaws, was greatly reduced after worldwide mass treatment. In 2005, cases were again reported in the Democratic Republic of the Congo. We carried out a survey to estimate the village-level prevalence of yaws in the region of Equator in the north of the country in order to define appropriate strategies to effectively treat the affected population. METHODOLOGY/PRINCIPAL FINDINGS: We designed a community-based su...

  17. 30 CFR 74.9 - Quality assurance.

    Science.gov (United States)

    2010-07-01

    ... CFR part 51. Persons may obtain a copy from the International Organization for Standardization at the... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Quality assurance. 74.9 Section 74.9 Mineral... DUST SAMPLING DEVICES Requirements for Continuous Personal Dust Monitors § 74.9 Quality assurance....

  18. Quality assurance program

    International Nuclear Information System (INIS)

    This topical report describes the Gibbs and Hill Quality Assurance Program and sets forth the methods to be followed in controlling quality-related activities performed by Gibbs and Hill and its contractors. The program is based on company experience in nuclear power and related work, and defines a system found effective in providing independent control of quality-related functions and documentation. The scope of the report covers activities involving nuclear safety-related structures, systems, and components covered by Gibbs and Hill' contractual obligation to the Utility Owner for each project

  19. Comprehensive method to analyze thick insulating samples using PIXE technique

    Science.gov (United States)

    Ismail, I. M.; Rihawy, M. S.

    2013-02-01

    In this work, we present a new method to analyze thick insulating samples by PIXE technique. The method is based on the use of both an electron flood gun to compensate the charge build-up at the insulating surface and a beam profile monitor (BPM) to provide a precise indirect measurement of the beam current and accumulated charge. A filament extracted from an ordinary flashlight lamp was used as an electron flood gun. While, a commercial BPM has been adapted in order to carry out charge measurements. The results have revealed the convenience of using BPM for measuring the charge in PIXE measurements. The use of the electron flood gun has given very satisfactory results in term of preventing charge build-up and reducing its contribution to the bremsstrahlung background in the PIXE spectra. The applicability and efficiency of the overall system for elemental analysis were successfully verified using IAEA-Soil-7 reference material where both accuracy and precision were found to be better than 10% in most cases.

  20. Martian Radiative Transfer Modeling Using the Optimal Spectral Sampling Method

    Science.gov (United States)

    Eluszkiewicz, J.; Cady-Pereira, K.; Uymin, G.; Moncet, J.-L.

    2005-01-01

    The large volume of existing and planned infrared observations of Mars have prompted the development of a new martian radiative transfer model that could be used in the retrievals of atmospheric and surface properties. The model is based on the Optimal Spectral Sampling (OSS) method [1]. The method is a fast and accurate monochromatic technique applicable to a wide range of remote sensing platforms (from microwave to UV) and was originally developed for the real-time processing of infrared and microwave data acquired by instruments aboard the satellites forming part of the next-generation global weather satellite system NPOESS (National Polarorbiting Operational Satellite System) [2]. As part of our on-going research related to the radiative properties of the martian polar caps, we have begun the development of a martian OSS model with the goal of using it to perform self-consistent atmospheric corrections necessary to retrieve caps emissivity from the Thermal Emission Spectrometer (TES) spectra. While the caps will provide the initial focus area for applying the new model, it is hoped that the model will be of interest to the wider Mars remote sensing community.

  1. Sequential sampling: a novel method in farm animal welfare assessment.

    Science.gov (United States)

    Heath, C A E; Main, D C J; Mullan, S; Haskell, M J; Browne, W J

    2016-02-01

    Lameness in dairy cows is an important welfare issue. As part of a welfare assessment, herd level lameness prevalence can be estimated from scoring a sample of animals, where higher levels of accuracy are associated with larger sample sizes. As the financial cost is related to the number of cows sampled, smaller samples are preferred. Sequential sampling schemes have been used for informing decision making in clinical trials. Sequential sampling involves taking samples in stages, where sampling can stop early depending on the estimated lameness prevalence. When welfare assessment is used for a pass/fail decision, a similar approach could be applied to reduce the overall sample size. The sampling schemes proposed here apply the principles of sequential sampling within a diagnostic testing framework. This study develops three sequential sampling schemes of increasing complexity to classify 80 fully assessed UK dairy farms, each with known lameness prevalence. Using the Welfare Quality herd-size-based sampling scheme, the first 'basic' scheme involves two sampling events. At the first sampling event half the Welfare Quality sample size is drawn, and then depending on the outcome, sampling either stops or is continued and the same number of animals is sampled again. In the second 'cautious' scheme, an adaptation is made to ensure that correctly classifying a farm as 'bad' is done with greater certainty. The third scheme is the only scheme to go beyond lameness as a binary measure and investigates the potential for increasing accuracy by incorporating the number of severely lame cows into the decision. The three schemes are evaluated with respect to accuracy and average sample size by running 100 000 simulations for each scheme, and a comparison is made with the fixed size Welfare Quality herd-size-based sampling scheme. All three schemes performed almost as well as the fixed size scheme but with much smaller average sample sizes. For the third scheme, an overall

  2. Confidence interval estimation by bootstrap method for uncertainty quantification using random sampling method

    International Nuclear Information System (INIS)

    Confidence interval estimation by the bootstrap method is investigated for the uncertainty quantification of neutronics calculation using the random sampling method. The random sampling method is a simple and practical technique to quantify an uncertainty (standard deviation) of the target parameter calculated by a core analysis code. It is noted that a statistical error is inevitably included in the estimated uncertainty because of the probabilistic method using random numbers. In order to estimate the statistical error of uncertainty, we focus on the bootstrap method. The bootstrap method is one of the resampling techniques to evaluate variance and confidence interval of a sample estimate (e.g. variance) without the assumption of normality. Through a lattice burnup calculation for a simplified boiling water reactor (BWR) fuel assembly, it is verified that the bootstrap method can reasonably estimate the confidence interval of uncertainty of infinite neutron multiplication factor (kinf) due to covariance data of JENDL-4.0. In the case of this problem, the distribution of kinf is well approximated by a normal distribution; thus, the confidence interval of uncertainty can be also estimated by the aid of chi-squared distribution. The merit using the bootstrap method is to simply estimate the confidence interval of uncertainty without the assumption of normality. (author)

  3. Quality assurance in the ambulatory care setting.

    Science.gov (United States)

    Tyler, R D

    1989-01-01

    One of the most utilitarian developments in the field of quality assurance in health care has been the introduction of industrial concepts of quality management. These concepts, coupled with buyer demand for accountability, are bringing new perspectives to health care quality assurance. These perspectives provide a new view of quality assurance as a major responsibility and strategic opportunity for management; a competitive and marketable commodity; and a method of improving safety, effectiveness, and satisfaction with medical care. PMID:10313405

  4. Comparison of two methods of tear sampling for protein quantification by Bradford method

    Directory of Open Access Journals (Sweden)

    Eliana Farias

    2013-02-01

    Full Text Available The aim of this study was to compare two methods of tear sampling for protein quantification. Tear samples were collected from 29 healthy dogs (58 eyes using Schirmer tear test (STT strip and microcapillary tubes. The samples were frozen at -80ºC and analyzed by the Bradford method. Results were analyzed by Student's t test. The average protein concentration and standard deviation from tears collected with microcapillary tube were 4.45mg/mL ±0.35 and 4,52mg/mL ±0.29 for right and left eyes respectively. The average protein concentration and standard deviation from tears collected with Schirmer Tear Test (STT strip were and 54.5mg/mL ±0.63 and 54.15mg/mL ±0.65 to right and left eyes respectively. Statistically significant differences (p<0.001 were found between the methods. In the conditions in which this study was conducted, the average protein concentration obtained with the Bradford test from tear samples obtained by Schirmer Tear Test (STT strip showed values higher than those obtained with microcapillary tube. It is important that concentration of tear protein pattern values should be analyzed according the method used to collect tear samples.

  5. Multinational Quality Assurance

    Science.gov (United States)

    Kinser, Kevin

    2011-01-01

    Multinational colleges and universities pose numerous challenges to the traditional models of quality assurance that are designed to validate domestic higher education. When institutions cross international borders, at least two quality assurance protocols are involved. To guard against fraud and abuse, quality assurance in the host country is…

  6. Computer software quality assurance

    International Nuclear Information System (INIS)

    The author defines some criteria for the evaluation of software quality assurance elements for applicability to the regulation of the nuclear industry. The author then analyses a number of software quality assurance (SQA) standards. The major extracted SQA elements are then discussed, and finally specific software quality assurance recommendations are made for the nuclear industry

  7. 40 CFR 761.243 - Standard wipe sample method and size.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Standard wipe sample method and size... Natural Gas Pipeline: Selecting Sample Sites, Collecting Surface Samples, and Analyzing Standard PCB Wipe Samples § 761.243 Standard wipe sample method and size. (a) Collect a surface sample from a natural...

  8. Precession electron diffraction using a digital sampling method

    International Nuclear Information System (INIS)

    A software-based method for collecting precession electron diffraction (PED) patterns is described. The PED patterns are obtained on a computer controlled transmission electron microscope. A series of electron diffraction (ED) patterns are collected as still ED frames at equal intervals, while the electron beam is precessed by one period (360o) around the optical axis. A PED pattern is obtained by combining the different ED frames, which resembles the sampling of a conventional PED pattern. Since intermediate ED frames are collected, it is possible to perform different post-processing strategies on the ED data. This can be used for geometric corrections to obtain accurate integrated intensities. The alignments and data collection are fully automated and controlled by software. The data quality is comparable to what can be achieved using specialized hardware for precession. The PED data can be used for structure solution and refinement with reasonably good R-values. -- Research Highlights: → Precession electron diffraction without an extra hardware. → Computer control of the electron beam in TEM. → Each different orientation saved as a separate file, allowing different processing. → Geometric (Lorentz) factors corrected for. → Electron precession without double spots.

  9. A cleaning method to minimize contaminant luminescence signal of empty sample carriers using off-the-shelf chemical agents

    International Nuclear Information System (INIS)

    Signals acquired during thermoluminescence or optically stimulated luminescence measurements must be completely free of any spurious and/or contamination signals to assure the credibility of the results, especially during exploratory research investigating the luminescence behavior of new materials. Experiments indicate that such unwanted signals may also stem from new (unused) and used empty sample carriers, namely cups and discs, which are widely used for such measurements, probably due to contamination from a fluorite and/or silica-related source. Fluorite and/or silicone oil appear to be the most likely sources of contamination, thus, their removal, along with any other possible source that exhibits undesirable luminescence behavior, is necessary. Conventional cleaning methods fail to eliminate such contaminants from empty cups and discs. In this work a new cleaning method is proposed incorporating off-the-shelf chemical agents. Results of thermoluminescence measurements highlight the efficiency of the new cleaning process, since it can completely remove any observed contaminants from both new and used sample carriers, of various shapes and/or materials. Consequently their signal is minimized even at relatively high beta-doses, where it is prominent, resulting in a clean and only sample-attributed signal. - Highlights: • New and used empty sample carriers suffer from contamination from a fluorite and silica-related source. • A new cleaning method for empty sample carriers is proposed using off-the-shelf chemical agents. • The new method can eliminate any contamination from empty sample holders of various shapes and/or materials. • Contamination signals are reduced to the background level even at relatively high doses (100 Gy)

  10. Sampling in Qualitative Research: Rationale, Issues, and Methods

    OpenAIRE

    Luborsky, Mark R.; Rubinstein, Robert L.

    1995-01-01

    In gerontology the most recognized and elaborate discourse about sampling is generally thought to be in quantitative research associated with survey research and medical research. But sampling has long been a central concern in the social and humanistic inquiry, albeit in a different guise suited to the different goals. There is a need for more explicit discussion of qualitative sampling issues. This article will outline the guiding principles and rationales, features, and practices of sampli...

  11. Spatial and Spectral Methods for Irregular Sampling in Computer Graphics

    OpenAIRE

    Heck, Daniel

    2013-01-01

    Most general rasterization algorithms in computer graphics are based on point sampling of the underlying images. In computer graphics, the sampling patterns being used are typically irreuglar, mainly to prevent moiré artifacts in rendered images. The best irregular sampling patterns have a blue noise characteristic in the spectral domain:such patterns achieve a particularly good trade-off between moiré prevention and noise-free rendition of low image frequencies. This thesis presents new expe...

  12. Multi-Scaling Sampling: An Adaptive Sampling Method for Discovering Approximate Association Rules

    Institute of Scientific and Technical Information of China (English)

    Cai-Yan Jia; Xie-Ping Gao

    2005-01-01

    One of the obstacles of the efficient association rule mining is the explosive expansion of data sets since it is costly or impossible to scan large databases, esp., for multiple times. A popular solution to improve the speed and scalability of the association rule mining is to do the algorithm on a random sample instead of the entire database. But how to effectively define and efficiently estimate the degree of error with respect to the outcome of the algorithm, and how to determine the sample size needed are entangling researches until now. In this paper, an effective and efficient algorithm is given based on the PAC (Probably Approximate Correct) learning theory to measure and estimate sample error. Then, a new adaptive, on-line, fast sampling strategy - multi-scaling sampling - is presented inspired by MRA (Multi-Resolution Analysis) and Shannon sampling theorem, for quickly obtaining acceptably approximate association rules at appropriate sample size. Both theoretical analysis and empirical study have showed that the sampling strategy can achieve a very good speed-accuracy trade-off.

  13. Proactive quality assurance in environmental research

    International Nuclear Information System (INIS)

    The Quality Assurance policy of the US Environmental Protection Agency (EPA) stipulates that every project involving environmentally related monitoring, measurements, and data collection activities must have a written and approved quality assurance project plan (QAPjP). A QAPjP is a written document which presents, in specific terms, the policies, organizations, objectives, functional activities, and the quality assurance/quality control activities designed to achieve the quality goals for data collection. In the research studies involving novel or non-routine measurements that use unvalidated methods, measurement quality goals are often difficult or impossible to specify at the beginning of the project for which a QAPjP must be written. Furthermore, it may not be possible for the QAPjP reviewers to evaluate the reasonableness of these goals without initial information about the system under study. For the project to evaluate chlorofluorocarbon for recycling from domestic refrigerators, the QAPjP incorporated standard analytical techniques used by industry. These techniques did not provide accuracy and precision or other validation information. For the initial version of the QAPjP, measurement quality goals were assigned based on limited experience. Quality assurance support was called upon to evaluate the performance of the measurement system for this project through a series of audits. The performance evaluation audits necessitated designing novel audit materials and sample delivery techniques. Continued interaction is necessary between the project and QA teams to permit evolution of reasonable data quality indicators for meaningful assessment of data quality. By treating the QAPjP as a living document that is updated and amended as more knowledge of a system is obtained, AQ becomes an integral part of the research program. This results in a greater understanding of the system under study

  14. A novel sampling method for the investigation of gut microbiota

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: In order to characterize the qualitative and quantitative microorganisms in different sites of the lower digestive tract (LDT) in healthy volunteers, a specific technique was developed for collecting mucous of the distal ileum, colon and rectum.METHODS: A polyethylene tube was designed to go through the colonoscope channel with a No. 8 French tube. In order to avoid internal contamination, the distal extremity was protected with a membrane of microfilm after being sterilized in ethilene oxid. To facilitate the aspiration of a precise volume, its interior was coated with silicone. One hundred microlliter (0.1 mL) sample of mucous was collected and transferred into an Eppenddorff tube containing nine hundred microlliter (0.9 mL) of VMGA-3 (viable medium of Goteborg). This procedure was repeated at each site of the LDT with a new sterilized catheter.RESULTS: All sites revealed the "non pathogenic"anaerobic bacteria Veillonella sp (average 105 colony forming units/mL-CFU/mL), allowing to conclude an environment of low oxidation-reduction potential (redox)in the LDT. It was also characterized the presence of Klebisiella sp with significant statistical predominance (SSP) in the ileum. Enterobacter sp was found with SSP in the sigmoid colon, BacteroideS sp non-pigmented (npg)and E. coli with SSP in the sigmoid colon and rectum,Enterococcus sp and Lactobacillus sp with SSP in the rectum, all in a mean concentration of 105 CFU/mL.CONCLUSION: This procedure is feasible and efficient and can point out a similar distribution of the aerobic and anaerobic bacteria with the presence of biological markers of normal microbiota in the LDT.

  15. Three phase stratified sampling with ratio method of estimation

    OpenAIRE

    Bijoy Kumar Pradhan

    2014-01-01

    In this paper a three phase sampling is proposed to estimate the population mean of character by a three phase stratified ratio estimator and some numerical results are presented to illustrate efficiency of the proposed procedure against possible alternative ones and from the expected cost optimum sample sizes on first, second and third phases are also calculated.

  16. Acoustically levitated droplets: a contactless sampling method for fluorescence studies.

    Science.gov (United States)

    Leiterer, Jork; Grabolle, Markus; Rurack, Knut; Resch-Genger, Ute; Ziegler, Jan; Nann, Thomas; Panne, Ulrich

    2008-01-01

    Acoustic levitation is used as a new tool to study concentration-dependent processes in fluorescence spectroscopy. With this technique, small amounts of liquid and solid samples can be measured without the need for sample supports or containers, which often limits signal acquisition and can even alter sample properties due to interactions with the support material. We demonstrate that, because of the small sample volume, fluorescence measurements at high concentrations of an organic dye are possible without the limitation of inner-filter effects, which hamper such experiments in conventional, cuvette-based measurements. Furthermore, we show that acoustic levitation of liquid samples provides an experimentally simple way to study distance-dependent fluorescence modulations in semiconductor nanocrystals. The evaporation of the solvent during levitation leads to a continuous increase of solute concentration and can easily be monitored by laser-induced fluorescence. PMID:18596335

  17. Quality assurance program plan for radionuclide airborne emissions monitoring

    International Nuclear Information System (INIS)

    This Quality Assurance Program Plan identifies quality assurance program requirements and addresses the various Westinghouse Hanford Company organizations and their particular responsibilities in regards to sample and data handling of radiological airborne emissions. This Quality Assurance Program Plan is prepared in accordance with and to written requirements

  18. Establishing a novel automated magnetic bead-based method for the extraction of DNA from a variety of forensic samples.

    Science.gov (United States)

    Witt, Sebastian; Neumann, Jan; Zierdt, Holger; Gébel, Gabriella; Röscheisen, Christiane

    2012-09-01

    Automated systems have been increasingly utilized for DNA extraction by many forensic laboratories to handle growing numbers of forensic casework samples while minimizing the risk of human errors and assuring high reproducibility. The step towards automation however is not easy: The automated extraction method has to be very versatile to reliably prepare high yields of pure genomic DNA from a broad variety of sample types on different carrier materials. To prevent possible cross-contamination of samples or the loss of DNA, the components of the kit have to be designed in a way that allows for the automated handling of the samples with no manual intervention necessary. DNA extraction using paramagnetic particles coated with a DNA-binding surface is predestined for an automated approach. For this study, we tested different DNA extraction kits using DNA-binding paramagnetic particles with regard to DNA yield and handling by a Freedom EVO(®)150 extraction robot (Tecan) equipped with a Te-MagS magnetic separator. Among others, the extraction kits tested were the ChargeSwitch(®)Forensic DNA Purification Kit (Invitrogen), the PrepFiler™Automated Forensic DNA Extraction Kit (Applied Biosystems) and NucleoMag™96 Trace (Macherey-Nagel). After an extensive test phase, we established a novel magnetic bead extraction method based upon the NucleoMag™ extraction kit (Macherey-Nagel). The new method is readily automatable and produces high yields of DNA from different sample types (blood, saliva, sperm, contact stains) on various substrates (filter paper, swabs, cigarette butts) with no evidence of a loss of magnetic beads or sample cross-contamination. PMID:22310206

  19. Computational methods assuring nuclear power plant structural integrity and safety: an overview of the recent activities at VTT

    International Nuclear Information System (INIS)

    Numerical, simplified engineering and standardised methods are applied in the safety analyses of primary circuit components and reactor pressure vessels. The integrity assessment procedures require input relating both to the steady state and transient loading actual material properties data and precise knowledge of the size and geometry of defects. Current procedures bold extensive information regarding these aspects. It is important to verify the accuracy of the different assessment methods especially in the case of complex structures and loading. The focus of this paper is on the recent results and development of computational fracture assessment methods at VTT Manufacturing Technology. The methods include effective engineering type tools for rapid structural integrity assessments and more sophisticated finite-element based methods. An integrated PC-based program system MASI for engineering fracture analysis is described. A summary of the verification of the methods in computational benchmark analyses and against the results of large scale experiments is presented. (orig.)

  20. High assurance SPIRAL

    Science.gov (United States)

    Franchetti, Franz; Sandryhaila, Aliaksei; Johnson, Jeremy R.

    2014-06-01

    In this paper we introduce High Assurance SPIRAL to solve the last mile problem for the synthesis of high assurance implementations of controllers for vehicular systems that are executed in today's and future embedded and high performance embedded system processors. High Assurance SPIRAL is a scalable methodology to translate a high level specification of a high assurance controller into a highly resource-efficient, platform-adapted, verified control software implementation for a given platform in a language like C or C++. High Assurance SPIRAL proves that the implementation is equivalent to the specification written in the control engineer's domain language. Our approach scales to problems involving floating-point calculations and provides highly optimized synthesized code. It is possible to estimate the available headroom to enable assurance/performance trade-offs under real-time constraints, and enables the synthesis of multiple implementation variants to make attacks harder. At the core of High Assurance SPIRAL is the Hybrid Control Operator Language (HCOL) that leverages advanced mathematical constructs expressing the controller specification to provide high quality translation capabilities. Combined with a verified/certified compiler, High Assurance SPIRAL provides a comprehensive complete solution to the efficient synthesis of verifiable high assurance controllers. We demonstrate High Assurance SPIRALs capability by co-synthesizing proofs and implementations for attack detection and sensor spoofing algorithms and deploy the code as ROS nodes on the Landshark unmanned ground vehicle and on a Synthetic Car in a real-time simulator.

  1. Data quality assurance in monitoring of wastewater quality: Univariate on-line and off-line methods

    DEFF Research Database (Denmark)

    Alferes, J.; Poirier, P.; Lamaire-Chad, C.;

    procedure is presented that combines univariate off-line and on-line methods to assess water quality sensors and to detect and replace doubtful data. While the off-line concept uses control charts for quality control, the on-line methods aim at outlier and fault detection by using autoregressive models...

  2. Quality assurance and statistical control

    DEFF Research Database (Denmark)

    Heydorn, K.

    In scientific research laboratories it is rarely possible to use quality assurance schemes, developed for large-scale analysis. Instead methods have been developed to control the quality of modest numbers of analytical results by relying on statistical control: Analysis of precision serves to...

  3. Task Technical and Quality Assurance Plan for Testing Methods to Reduce 235 Uranium Enrichment in Tank 43H Supernatant Liquid

    International Nuclear Information System (INIS)

    In July of 1997, the 2H-Evaporator was shutdown due to the inability to lift material from the vessel. Inspections of the gravity drain line (GDL) showed a scale deposit coating the inside of the line. A Sample of the material was obtained and analyses performed. Plans are to chemically clean the evaporator pot by dissolving the solids in a 1.5M nitric acid solution containing depleted uranium

  4. Methods of sampling airborne fungi in working environments of waste treatment facilities

    OpenAIRE

    Kristýna Černá; Zdeňka Wittlingerová; Magdaléna Zimová; Zdeněk Janovský

    2016-01-01

    Objectives: The objective of the present study was to evaluate and compare the efficiency of a filter based sampling method and a high volume sampling method for sampling airborne culturable fungi present in waste sorting facilities. Material and Methods: Membrane filters method was compared with surface air system method. The selected sampling methods were modified and tested in 2 plastic waste sorting facilities. Results: The total number of colony-forming units (CFU)/m3 of airborne fungi w...

  5. The method of Sample Management in Neutron Activation Analysis Laboratory-Serpong

    International Nuclear Information System (INIS)

    In the testing laboratory used by neutron activation analysis method, sample preparation is the main factor and it can't be neglect. The error in the sample preparation can give result with lower accuracy. In this article is explained the scheme of sample preparation i.e sample receive administration, the separate of sample, fluid and solid sample preparation, sample grouping, irradiation, sample counting and holding the sample post irradiation. If the management of samples were good application based on Standard Operation Procedure, therefore each samples has good traceability. To optimize the management of samples is needed the trained and skilled personal and good facility. (author)

  6. Ten years of balanced sampling with the cube method: An appraisal

    OpenAIRE

    Tillé, Yves

    2016-01-01

    This paper presents a review and assessment of the use of balanced sampling by means of the cube method. After defining the notion of balanced sample and balanced sampling, a short history of the concept of balancing is presented. The theory of the cube method is briefly presented. Emphasis is placed on the practical problems posed by balanced sampling: the interest of the method with respect to other sampling methods and calibration, the field of application, the accuracy of balancing, the c...

  7. Statistical Methods and Tools for Hanford Staged Feed Tank Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Fountain, Matthew S.; Brigantic, Robert T.; Peterson, Reid A.

    2013-10-01

    This report summarizes work conducted by Pacific Northwest National Laboratory to technically evaluate the current approach to staged feed sampling of high-level waste (HLW) sludge to meet waste acceptance criteria (WAC) for transfer from tank farms to the Hanford Waste Treatment and Immobilization Plant (WTP). The current sampling and analysis approach is detailed in the document titled Initial Data Quality Objectives for WTP Feed Acceptance Criteria, 24590-WTP-RPT-MGT-11-014, Revision 0 (Arakali et al. 2011). The goal of this current work is to evaluate and provide recommendations to support a defensible, technical and statistical basis for the staged feed sampling approach that meets WAC data quality objectives (DQOs).

  8. Mathematical Optimum of the Audit Sample

    OpenAIRE

    Georgeta Ancuta Span; Irimie Emil Popa

    2012-01-01

    Problem statement: The primary objective of any audit mission is to obtain a high level of assurance on the fact that financial statements are prepared in accordance with a general financial reporting framework. Getting an absolute level of assurance is not possible due to the complexity and big number of transactions and operations found in practice. This research aims to identify the shortcomings of one of the sampling methods used by the Romania auditors (80/20 method) and it was proposed ...

  9. Method for validating radiobiological samples using a linear accelerator

    International Nuclear Information System (INIS)

    There is an immediate need for rapid triage of the population in case of a large scale exposure to ionizing radiation. Knowing the dose absorbed by the body will allow clinicians to administer medical treatment for the best chance of recovery for the victim. In addition, today's radiotherapy treatment could benefit from additional information regarding the patient's sensitivity to radiation before starting the treatment. As of today, there is no system in place to respond to this demand. This paper will describe specific procedures to mimic the effects of human exposure to ionizing radiation creating the tools for optimization of administered radiation dosimetry for radiotherapy and/or to estimate the doses of radiation received accidentally during a radiation event that could pose a danger to the public. In order to obtain irradiated biological samples to study ionizing radiation absorbed by the body, we performed ex-vivo irradiation of human blood samples using the linear accelerator (LINAC). The LINAC was implemented and calibrated for irradiating human whole blood samples. To test the calibration, a 2 Gy test run was successfully performed on a tube filled with water with an accuracy of 3% in dose distribution. To validate our technique the blood samples were ex-vivo irradiated and the results were analyzed using a gene expression assay to follow the effect of the ionizing irradiation by characterizing dose responsive biomarkers from radiobiological assays. The response of 5 genes was monitored resulting in expression increase with the dose of radiation received. The blood samples treated with the LINAC can provide effective irradiated blood samples suitable for molecular profiling to validate radiobiological measurements via the gene-expression based biodosimetry tools. (orig.)

  10. Revitalizing quality assurance

    International Nuclear Information System (INIS)

    The image of someone inspecting or auditing often comes to mind when people hear the term quality assurance. Although partially correct, this image is not the complete picture. The person doing the inspecting or auditing is probably part of a traditional quality assurance organization, but that organization is only one aspect of a properly conceived and effectively implemented quality assurance system whose goal is improved facility safety and reliability. This paper introduces the underlying philosophies and basic concepts of the International Atomic Energy Agency's new quality assurance initiative that began in 1991 as part of a broad Agency-wide program to enhance nuclear safety. The first product of that initiative was publication in 1996 of a new Quality Assurance Code 50-C/SG-Q and fourteen related Safety Guides. This new suite of documents provide the technical and philosophical foundation upon which Member States can base their quality assurance programs. (author)

  11. Apparatus and method for centrifugation and robotic manipulation of samples

    Science.gov (United States)

    Vellinger, John C. (Inventor); Ormsby, Rachel A. (Inventor); Kennedy, David J. (Inventor); Thomas, Nathan A. (Inventor); Shulthise, Leo A. (Inventor); Kurk, Michael A. (Inventor); Metz, George W. (Inventor)

    2007-01-01

    A device for centrifugation and robotic manipulation of specimen samples, including incubating eggs, and uses thereof are provided. The device may advantageously be used for the incubation of avian, reptilian or any type of vertebrate eggs. The apparatus comprises a mechanism for holding samples individually, rotating them individually, rotating them on a centrifuge collectively, injecting them individually with a fixative or other chemical reagent, and maintaining them at controlled temperature, relative humidity and atmospheric composition. The device is applicable to experiments involving entities other than eggs, such as invertebrate specimens, plants, microorganisms and molecular systems.

  12. Examination of beam profile measurement using an imaging plate by the light exposure fading method for quality assurance of external radiation therapy

    International Nuclear Information System (INIS)

    High-resolution film dosimetry has been used for several decades to check and to measure two-dimensional dose distributions. However, in recent years, the automatic processor has been replaced by the spread of computed radiography, or has been little used hospitals. In this study, we measured the off-center ratio (OCR) of the open field, after an irradiating radiation beam was delivered to the imaging plate (IP) under conditions in which the IP was exposed to a fixed amount of light with fading, and compared these data with the OCR measured by an ionization-chamber dosimeter, which is the standard method used for measuring radiation dose. Profile measurement using IP could be achieved by performing light fading, even at a range of more than 100 MU. Further, by using a metallic filter, we succeeded in demonstrating that the profile measurement of IP in an open irradiation field could approximate the values of those obtained by an ionization chamber dosimeter. This method can serve as a simple, easy-to-use method for evaluating the quality assurance (QA) of dose distribution in radiation therapy. (author)

  13. Biphasic dissolution method for quality control and assurance of drugs containing active substances in the form of weak acid salts.

    Science.gov (United States)

    Franc, Aleš; Muselłk, Jan; Goněc, Roman; Vetchý, David

    2016-03-01

    Substances in the form of weak acid salts have been found to be problematic for dissolution testing. Their absorption can start only after they are turned into the form of an acid following the gastric passage although they were administered in the form of a salt. Due to poor solubility, they cannot be tested in acidic gastric environment for a biased dissolution profile. The biphasic dissolution method is promising for overcoming this obstacle. Tablets with warfarin clathrate sodium salt in two concentrations and two different particle size distributions were tested as a suitable model for finding the medium and process conditions of dissolution. The dissolution method based on the use of the upper organic layer (1-octanol) and the lower aqueous layer 0.1 mol L-1 HCl) was found suitable and discriminatory for tablets containing active substances in the form of salts of weak acids. The method also reflects physical differences in the quality of used substances. PMID:26959550

  14. A rapid wire-based sampling method for DNA profiling.

    Science.gov (United States)

    Chen, Tong; Catcheside, David E A; Stephenson, Alice; Hefford, Chris; Kirkbride, K Paul; Burgoyne, Leigh A

    2012-03-01

    This paper reports the results of a commission to develop a field deployable rapid short tandem repeat (STR)-based DNA profiling system to enable discrimination between tissues derived from a small number of individuals. Speed was achieved by truncation of sample preparation and field deployability by use of an Agilent 2100 Bioanalyser(TM). Human blood and tissues were stabbed with heated stainless steel wire and the resulting sample dehydrated with isopropanol prior to direct addition to a PCR. Choice of a polymerase tolerant of tissue residues and cycles of amplification appropriate for the amount of template expected yielded useful profiles with a custom-designed quintuplex primer set suitable for use with the Bioanalyser(TM). Samples stored on wires remained amplifiable for months, allowing their transportation unrefrigerated from remote locations to a laboratory for analysis using AmpFlSTR(®) Profiler Plus(®) without further processing. The field system meets the requirements for discrimination of samples from small sets and retains access to full STR profiling when required. PMID:22211864

  15. Improved sample management in the cylindrical-tube microelectrophoresis method

    Science.gov (United States)

    Smolka, A. J. K.

    1980-01-01

    A modification to an analytical microelectrophoresis system is described that improves the manipulation of the sample particles and fluid. The apparatus modification and improved operational procedure should yield more accurate measurements of particle mobilities and permit less skilled operators to use the apparatus.

  16. Rapid methods for measuring radionuclides in food and environmental samples

    International Nuclear Information System (INIS)

    The application of ICP/mass spectrometry for the isotopic analysis of environmental samples, the use of drum assayers for measuring radionuclides in food and a rapid procedure for the measurement of the transuranic elements and thorium, performed at the Pacific Northwest Laboratory are discussed

  17. Validation of EIA sampling methods - bacterial and biochemical analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Sheelu, G.; LokaBharathi, P.A.; Nair, S.; Raghukumar, C.; Mohandass, C.

    Deep sea sediments from Central Indian Ocean Basin (CIOB) were sampled from 10 degrees .00'-10 degrees .10'S latitude and 75 degrees .55'-76 degrees .05'E longitude for assessing the potential environmental impact of polymetallic nodule mining under...

  18. An Importance Sampling Simulation Method for Bayesian Decision Feedback Equalizers

    OpenAIRE

    Chen, S.; Hanzo, L.

    2000-01-01

    An importance sampling (IS) simulation technique is presented for evaluating the lower-bound bit error rate (BER) of the Bayesian decision feedback equalizer (DFE) under the assumption of correct decisions being fed back. A design procedure is developed, which chooses appropriate bias vectors for the simulation density to ensure asymptotic efficiency of the IS simulation.

  19. Rapid methods for strontium determination in environmental samples

    International Nuclear Information System (INIS)

    The simultaneous determination of strontium-90 and strontium-89 is usually done by separation of yttrium-90 after a suitable time for the growth of yttrium-90. Investigations are of interest to try a yttrium-90 measurement without separation by observing the increase of activity of the strontium sample due to the production and decay of the daughter nuclide yttrium-90. Also it can be tried to use liquid scintillation spectroscopy to discriminate strontium-89 (1.46 MeV) from strontium-90 (0.55 MeV) immediately after the strontium precipitation. Until now all these determinations are only possible if the strontium-90 activity is not too low compared with the the strontium-89 content of the sample. Unfortunately regarding this possibility of determination but fortunately from the point of view of radiation protection immediately after a nuclear accident in most cases the activity of strontium-90 is much lower than that of strontium-89. Liquid scintillation spectroscopy does not give reliable results for low strontium-90 activity if a high strontium-89 activity is observed in a sample. The growth of yttrium-90 in a sample of strontium-89/90 will increase the total activity. After a suitable period of time this increase might be sufficiently high to provide reliable information about the strontium-90 content. Due to statistics no reliable information will be provided for samples with an excess of strontium-89. If the strontium-89 activity is 20 times higher than the strontium-90 activity, no reliable information can be obtained, if it is 5 times higher, it is possible to provide a quantitative information about the growth of yttrium-90 after 36 hours, and if twice the activity of strontium-89 compared to the strontium-90 were observed, there would be no difficulties for the simultaneous determination of both radionuclides. Dealing with the situation of high strontium-89 contribution an yttrium separation probably is unavoidable

  20. Prevalence of Mixed-Methods Sampling Designs in Social Science Research

    Science.gov (United States)

    Collins, Kathleen M. T.

    2006-01-01

    The purpose of this mixed-methods study was to document the prevalence of sampling designs utilised in mixed-methods research and to examine the interpretive consistency between interpretations made in mixed-methods studies and the sampling design used. Classification of studies was based on a two-dimensional mixed-methods sampling model. This…

  1. Testing K. Patrick Method of Psychopathy Diagnosis in Russian Sample

    OpenAIRE

    Atadzhykova Y.A.,; Enikolopov S. N.,

    2015-01-01

    The article is devoted to the development of a method of diagnosing psychopathy, or antisocial (dissocial) personality disorder. Modern researchers mostly use the methods of experiment, expert assessment, clinical interview or different combinations for personality disorders, including psychopathy. However, nowadays there is a growing need in development of a psychopathy diagnosis method which would be less labour-intensive, less expensive and more objective. One of the recently developed mod...

  2. Estimation of uranium in columbite-tantalite samples: a method for sample solution preparation for fluorimetric estimation

    International Nuclear Information System (INIS)

    A method has been developed for obtaining a clear solution of columbite-tantalite samples in nitric acid medium before the fluorimetric estimation of uranium. Ammonium hydrogen fluoride is used to keep tantalum, niobium and titanium dissolved in the acid medium. The excess of fluoride is complexed with boric acid. The method has been successfully applied to a number of synthetic and natural columbite-tantalite samples. (author)

  3. Contaminated soil remediation and quality assurance; Pilaantuneen maan kunnostaminen ja laadunvarmistus

    Energy Technology Data Exchange (ETDEWEB)

    Sarkkila, J.; Mroueh, U.M.; Leino-Forsman, H.

    2004-07-01

    The aim of contaminated soil remediation quality assurance is to carry out remediation activities according to plans. Besides the design work the appropriate implementation of the quality assurance covers source data and investigation methods as well as the requirements for documentation. Contaminated soil characterization and the selection of the most suitable remediation method is made with the help of various sampling and analysis methods. There are different kinds of requirements to the sampling plan depending on the type of remediation project. Quality assurance is taken into account in sampling, in sample handling and analysis as well as in the reporting of results. The most common unsaturated zone remediation methods used in Finland are introduced in this guide. These methods include excavation (as part of remediation), encapsulating, stabilization, thermal desorption, soil washing, composting, soil vapor extraction and bioventing. The methods are introduced on a general level with emphasis on their technical implementation and feasibility as well as on the eventual material requirements. Harmful environmental impacts of the methods must be identified and prevented. In order to monitor the remediation process, various chemical and physical quality assurance measurements are performed. Additionally the work safety issues related to remediation methods must be taken into account and proper documentation must be prepared. (orig.)

  4. Microbial diversity in fecal samples depends on DNA extraction method

    DEFF Research Database (Denmark)

    Mirsepasi, Hengameh; Persson, Søren; Struve, Carsten;

    2014-01-01

    was to evaluate two different DNA extraction methods in order to choose the most efficient method for studying intestinal bacterial diversity using Denaturing Gradient Gel Electrophoresis (DGGE). FINDINGS: In this study, a semi-automatic DNA extraction system (easyMag®, BioMérieux, Marcy I'Etoile, France...

  5. Private sector delivery of health services in developing countries: a mixed-methods study on quality assurance in social franchises

    OpenAIRE

    Schlein Karen; De La Cruz Anna York; Gopalakrishnan Tisha; Montagu Dominic

    2013-01-01

    Abstract Background Across the developing world health care services are most often delivered in the private sector and social franchising has emerged, over the past decade, as an increasingly popular method of private sector health care delivery. Social franchising aims to strengthen business practices through economies of scale: branding clinics and purchasing drugs in bulk at wholesale prices. While quality is one of the established goals of social...

  6. Method for Spiking Soil Samples with Organic Compounds

    OpenAIRE

    Brinch, Ulla C.; Ekelund, Flemming; Jacobsen, Carsten S.

    2002-01-01

    We examined the harmful side effects on indigenous soil microorganisms of two organic solvents, acetone and dichloromethane, that are normally used for spiking of soil with polycyclic aromatic hydrocarbons for experimental purposes. The solvents were applied in two contamination protocols to either the whole soil sample or 25% of the soil volume, which was subsequently mixed with 75% untreated soil. For dichloromethane, we included a third protocol, which involved application to 80% of the so...

  7. Sample preparation method for induced mutation on orchid

    International Nuclear Information System (INIS)

    Studies on the induction of mutation in Dendrobium orchid at MINT has produced a number of new orchid mutant cultivars. Tissue culture techniques on orchid seeds and meristem cloning are employed in preparing the samples for the mutation induction. Solid medium based on the Murashige and Skoog (1962) and liquid medium based on Vacin and Went (1949) were found to be suitable in producing protocorm like bodies (PLBs) that are required for the irradiation treatment. (Author)

  8. Analytical results, database management and quality assurance for analysis of soil and groundwater samples collected by cone penetrometer from the F and H Area seepage basins

    International Nuclear Information System (INIS)

    The Quantification of Soil Source Terms and Determination of the Geochemistry Controlling Distribution Coefficients (Kd values) of Contaminants at the F- and H-Area Seepage Basins (FHSB) study was designed to generate site-specific contaminant transport factors for contaminated groundwater downgradient of the Basins. The experimental approach employed in this study was to collect soil and its associated porewater from contaminated areas downgradient of the FHSB. Samples were collected over a wide range of geochemical conditions (e.g., pH, conductivity, and contaminant concentration) and were used to describe the partitioning of contaminants between the aqueous phase and soil surfaces at the site. The partitioning behavior may be used to develop site-specific transport factors. This report summarizes the analytical procedures and results for both soil and porewater samples collected as part of this study and the database management of these data

  9. Randomized Interior Point methods for Sampling and Optimization

    CERN Document Server

    Narayanan, Hariharan

    2009-01-01

    All known Markov Chains for sampling a general convex set have mixing times that depend upon the aspect ratio of the convex set, a measure of which is the ratio between the radius of the smallest sphere circumscribed around $K$ and the radius of the largest sphere inscribed in $K$. Extending earlier work on polytopes, we present a Markov chain for sampling from a convex body using a self-concordant barrier, whose mixing time does not depend on its aspect ratio or diameter. The mixing time of this chain is invariant under affine transformations of the convex set, thus eliminating the need for first placing the body in an isotropic position. Whether the body is in isotropic position or not, if it is the intersection of $O(n^{1 - \\eps})$ ellipsoids or the feasible set corresponding to semi-definite constraints of rank $O(n^{1-\\eps})$, the bounds on the mixing time improve upon existing bounds. In the cases where the self-concordant barrier has a tractable closed form, the Markov chain leads to efficient sampling...

  10. A new method of snowmelt sampling for water stable isotopes

    Science.gov (United States)

    Penna, D.; Ahmad, M.; Birks, S. J.; Bouchaou, L.; Brencic, M.; Butt, S.; Holko, L.; Jeelani, G.; Martinez, D. E.; Melikadze, G.; Shanley, J.B.; Sokratov, S. A.; Stadnyk, T.; Sugimoto, A.; Vreca, P.

    2014-01-01

    We modified a passive capillary sampler (PCS) to collect snowmelt water for isotopic analysis. Past applications of PCSs have been to sample soil water, but the novel aspect of this study was the placement of the PCSs at the ground-snowpack interface to collect snowmelt. We deployed arrays of PCSs at 11 sites in ten partner countries on five continents representing a range of climate and snow cover worldwide. The PCS reliably collected snowmelt at all sites and caused negligible evaporative fractionation effects in the samples. PCS is low-cost, easy to install, and collects a representative integrated snowmelt sample throughout the melt season or at the melt event scale. Unlike snow cores, the PCS collects the water that would actually infiltrate the soil; thus, its isotopic composition is appropriate to use for tracing snowmelt water through the hydrologic cycle. The purpose of this Briefing is to show the potential advantages of PCSs and recommend guidelines for constructing and installing them based on our preliminary results from two snowmelt seasons.

  11. Sample preparation method for ICP-MS measurement of 99Tc in a large amount of environmental samples

    International Nuclear Information System (INIS)

    Sample preparation for measurement of 99Tc in a large amount of soil and water samples by ICP-MS has been developed using 95mTc as a yield tracer. This method is based on the conventional method for a small amount of soil samples using incineration, acid digestion, extraction chromatography (TEVA resin) and ICP-MS measurement. Preliminary concentration of Tc has been introduced by co-precipitation with ferric oxide. The matrix materials in a large amount of samples were more sufficiently removed with keeping the high recovery of Tc than previous method. The recovery of Tc was 70-80% for 100 g soil samples and 60-70% for 500 g of soil and 500 L of water samples. The detection limit of this method was evaluated as 0.054 mBq/kg in 500 g soil and 0.032 μBq/L in 500 L water. The determined value of 99Tc in the IAEA-375 (soil sample collected near the Chernobyl Nuclear Reactor) was 0.25 ± 0.02 Bq/kg. (author)

  12. Processes and procedures for a worldwide biological samples distribution; product assurance and logistic activities to support the mice drawer system tissue sharing event

    Science.gov (United States)

    Benassai, Mario; Cotronei, Vittorio

    The Mice Drawer System (MDS) is a scientific payload developed by the Italian Space Agency (ASI), it hosted 6 mice on the International Space Station (ISS) and re-entered on ground on November 28, 2009 with the STS 129 at KSC. Linked to the MDS experiment, a Tissue Sharing Program (TSP), was developed in order to make available to 16 Payload Investigators (PI) (located in USA, Canada, EU -Italy, Belgium and Germany -and Japan) the biological samples coming from the mice. ALTEC SpA (a PPP owned by ASI, TAS-I and local institutions) was responsible to support the logistics aspects of the MDS samples for the first MDS mission, in the frame of Italian Space Agency (ASI) OSMA program (OSteoporosis and Muscle Atrophy). The TSP resulted in a complex scenario, as ASI, progressively, extended the original OSMA Team also to researchers from other ASI programs and from other Agencies (ESA, NASA, JAXA). The science coordination was performed by the University of Genova (UNIGE). ALTEC has managed all the logistic process with the support of a specialized freight forwarder agent during the whole shipping operation phases. ALTEC formalized all the steps from the handover of samples by the dissection Team to the packaging and shipping process in a dedicated procedure. ALTEC approached all the work in a structured way, performing: A study of the aspects connected to international shipments of biological samples. A coopera-tive work with UNIGE/ASI /PIs to identify all the needs of the various researchers and their compatibility. A complete revision and integration of shipment requirements (addresses, tem-peratures, samples, materials and so on). A complete definition of the final shipment scenario in terms of boxes, content, refrigerant and requirements. A formal approach to identification and selection of the most suited and specialized Freight Forwarder. A clear identification of all the processes from sample dissection by PI Team, sample processing, freezing, tube preparation

  13. On-line sample processing methods in flow analysis

    DEFF Research Database (Denmark)

    Miró, Manuel; Hansen, Elo Harald

    2008-01-01

    -line dilution, derivatization, separation and preconcentration methods encompassing solid reactors, solvent extraction, sorbent extraction, precipitation/coprecipitation, hydride/vapor generation and digestion/leaching protocols as hyphenated to a plethora of detection devices is discussed in detail and...

  14. Capture-recapture and removal methods for sampling closed populations

    Science.gov (United States)

    White, Gary C.; Anderson, David R.; Burnham, Kenneth P.; Otis, David L.

    1982-01-01

    The problem of estimating animal abundance is common in wildlife management and environmental impact asessment. Capture-recapture and removal methods are often used to estimate population size. Statistical Inference From Capture Data On Closed Animal Populations, a monograph by Otis et al. (1978), provides a comprehensive synthesis of much of the wildlife and statistical literature on the methods, as well as some extensions of the general theory. In our primer, we focus on capture-recapture and removal methods for trapping studies in which a population is assumed to be closed and do not treat open-population models, such as the Jolly-Seber model, or catch-effort methods in any detail. The primer, written for students interested in population estimation, is intended for use with the more theoretical monograph.

  15. [DOE method for evaluating environmental and waste management samples: Revision 1, Addendum 1

    Energy Technology Data Exchange (ETDEWEB)

    Goheen, S.C.

    1995-04-01

    The US Dapartment of Energy`s (DOE`s) environmental and waste management (EM) sampling and analysis activities require that large numbers of samples be analyzed for materials characterization, environmental surveillance, and site-remediation programs. The present document, DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods), is a supplemental resource for analyzing many of these samples.

  16. [DOE method for evaluating environmental and waste management samples: Revision 1, Addendum 1

    International Nuclear Information System (INIS)

    The US Dapartment of Energy's (DOE's) environmental and waste management (EM) sampling and analysis activities require that large numbers of samples be analyzed for materials characterization, environmental surveillance, and site-remediation programs. The present document, DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods), is a supplemental resource for analyzing many of these samples

  17. Method for spiking soil samples with organic compounds

    DEFF Research Database (Denmark)

    Brinch, Ulla C; Ekelund, Flemming; Jacobsen, Carsten S

    2002-01-01

    We examined the harmful side effects on indigenous soil microorganisms of two organic solvents, acetone and dichloromethane, that are normally used for spiking of soil with polycyclic aromatic hydrocarbons for experimental purposes. The solvents were applied in two contamination protocols to either......,000-fold higher than in control soil, probably due mainly to release of predation from indigenous protozoa. In order to minimize solvent effects on indigenous soil microorganisms when spiking native soil samples with compounds having a low water solubility, we propose a common protocol in which the...

  18. SU-E-T-570: New Quality Assurance Method Using Motion Tracking for 6D Robotic Couches

    International Nuclear Information System (INIS)

    Purpose: To accommodate geometrically accurate patient positioning, a robotic couch that is capable of 6-degrees of freedom has been introduced. However, conventional couch QA methods are not sufficient to enable the necessary accuracy of tests. Therefore, we have developed a camera based motion detection and geometry calibration system for couch QA. Methods: Employing a Visual-Tracking System (VTS, BonitaB10, Vicon, UK) which tracks infrared reflective(IR) markers, camera calibration was conducted using a 5.7 × 5.7 × 5.7 cm3 cube attached with IR markers at each corner. After positioning a robotic-couch at the origin with the cube on the table top, 3D coordinates of the cube’s eight corners were acquired by VTS in the VTS coordinate system. Next, positions in reference coordinates (roomcoordinates) were assigned using the known relation between each point. Finally, camera calibration was completed by finding a transformation matrix between VTS and reference coordinate systems and by applying a pseudo inverse matrix method. After the calibration, the accuracy of linear and rotational motions as well as couch sagging could be measured by analyzing the continuously acquired data of the cube while the couch moves to a designated position. Accuracy of the developed software was verified through comparison with measurement data when using a Laser tracker (FARO, Lake Mary, USA) for a robotic-couch installed for proton therapy. Results: VTS system could track couch motion accurately and measured position in room-coordinates. The VTS measurements and Laser tracker data agreed within 1% of difference for linear and rotational motions. Also because the program analyzes motion in 3-Dimension, it can compute couch sagging. Conclusion: Developed QA system provides submillimeter/ degree accuracy which fulfills the high-end couch QA. This work was supported by the National Research Foundation of Korea funded by Ministry of Science, ICT & Future Planning. (2013M2A2A7043507 and

  19. SU-E-T-570: New Quality Assurance Method Using Motion Tracking for 6D Robotic Couches

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, W; Cho, J [SungKyunKwan University, Seoul (Korea, Republic of); Ahn, S [Samsung Medical Center, Seoul (Korea, Republic of); Han, Y; Choi, D [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: To accommodate geometrically accurate patient positioning, a robotic couch that is capable of 6-degrees of freedom has been introduced. However, conventional couch QA methods are not sufficient to enable the necessary accuracy of tests. Therefore, we have developed a camera based motion detection and geometry calibration system for couch QA. Methods: Employing a Visual-Tracking System (VTS, BonitaB10, Vicon, UK) which tracks infrared reflective(IR) markers, camera calibration was conducted using a 5.7 × 5.7 × 5.7 cm{sup 3} cube attached with IR markers at each corner. After positioning a robotic-couch at the origin with the cube on the table top, 3D coordinates of the cube’s eight corners were acquired by VTS in the VTS coordinate system. Next, positions in reference coordinates (roomcoordinates) were assigned using the known relation between each point. Finally, camera calibration was completed by finding a transformation matrix between VTS and reference coordinate systems and by applying a pseudo inverse matrix method. After the calibration, the accuracy of linear and rotational motions as well as couch sagging could be measured by analyzing the continuously acquired data of the cube while the couch moves to a designated position. Accuracy of the developed software was verified through comparison with measurement data when using a Laser tracker (FARO, Lake Mary, USA) for a robotic-couch installed for proton therapy. Results: VTS system could track couch motion accurately and measured position in room-coordinates. The VTS measurements and Laser tracker data agreed within 1% of difference for linear and rotational motions. Also because the program analyzes motion in 3-Dimension, it can compute couch sagging. Conclusion: Developed QA system provides submillimeter/ degree accuracy which fulfills the high-end couch QA. This work was supported by the National Research Foundation of Korea funded by Ministry of Science, ICT & Future Planning. (2013M2A2A

  20. Program system SADKO-2 for assurance of high-energy radiation transport calculation by the group constant methods

    International Nuclear Information System (INIS)

    The structure of the SADKO-2 program system, providing for calculations of radiation transport by the group methods for protons, π-mesons within the energy range from 20 MeV to 10 TeV; for neutrons-from the thermal one to 10 TeV; for photons-from 0.01 up to 15 MeV. The SADKO system containing the program for calculation of complete and twice-differential cross section of inelastic hA-interaction, the program for calculation of group microcross sections for particles with energy above 20 MeV and the program for calculation of group microcross sections for isotope mixtures. The file of the group cross sections in a predetermined format, prepared with an account of the components composition of the shielding and detector substance, constitute the result of the SADKO-2 constant system operation. 25 refs., 7 figs

  1. Ant colony optimization as a method for strategic genotype sampling.

    Science.gov (United States)

    Spangler, M L; Robbins, K R; Bertrand, J K; Macneil, M; Rekaya, R

    2009-06-01

    A simulation study was carried out to develop an alternative method of selecting animals to be genotyped. Simulated pedigrees included 5000 animals, each assigned genotypes for a bi-allelic single nucleotide polymorphism (SNP) based on assumed allelic frequencies of 0.7/0.3 and 0.5/0.5. In addition to simulated pedigrees, two beef cattle pedigrees, one from field data and the other from a research population, were used to test selected methods using simulated genotypes. The proposed method of ant colony optimization (ACO) was evaluated based on the number of alleles correctly assigned to ungenotyped animals (AK(P)), the probability of assigning true alleles (AK(G)) and the probability of correctly assigning genotypes (APTG). The proposed animal selection method of ant colony optimization was compared to selection using the diagonal elements of the inverse of the relationship matrix (A(-1)). Comparisons of these two methods showed that ACO yielded an increase in AK(P) ranging from 4.98% to 5.16% and an increase in APTG from 1.6% to 1.8% using simulated pedigrees. Gains in field data and research pedigrees were slightly lower. These results suggest that ACO can provide a better genotyping strategy, when compared to A(-1), with different pedigree sizes and structures. PMID:19220227

  2. High assurance services computing

    CERN Document Server

    2009-01-01

    Covers service-oriented technologies in different domains including high assurance systemsAssists software engineers from industry and government laboratories who develop mission-critical software, and simultaneously provides academia with a practitioner's outlook on the problems of high-assurance software development

  3. Authentication Assurance Levels

    International Nuclear Information System (INIS)

    This Common Criteria approach has been applied to create a definition of Authentication Assurance Levels that can quantify the level of assurance reached for a system subject to a set of authentication procedures. The arms-control authentication application of the Common Criteria expands on more typical information security evaluations in that it must contend with information barriers and preclude sophisticated intentional subversion attempts.

  4. Quality assurance program

    International Nuclear Information System (INIS)

    The concept of levels of quality assurance as applied to CANDU-type nuclear power plant components, i.e. maintaining an appropriate cost/benefit ratio, is introduced. The design process itself has quality assurance features by virtue of multi-level review. (E.C.B.)

  5. Quality Assurance in Higher Education: Proposals for Consultation.

    Science.gov (United States)

    Higher Education Funding Council for England, Bristol.

    This document sets out for consultation proposals for a revised method for quality assurance of teaching and learning in higher education. The proposals cover: (1) the objectives and principles of quality assurance; (2) an approach to quality assurance based on external audit principles; (3) the collection and publication of information; (4)…

  6. Internal Quality Assurance System and Its Implementation in Kaunas College

    Science.gov (United States)

    Misiunas, Mindaugas

    2007-01-01

    The article discusses the internal system of quality assurance and its implementation methods in Kaunas College. The issues of quality assurance are reviewed in the context of the European higher education area covering the three levels: European, national and institutional. The importance of quality assurance and its links with external…

  7. 7 CFR 51.308 - Methods of sampling and calculation of percentages.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Methods of sampling and calculation of percentages. 51..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples Methods of Sampling and Calculation of Percentages § 51.308 Methods of sampling and calculation of percentages. (a) When the...

  8. 43 CFR 11.64 - Injury determination phase-testing and sampling methods.

    Science.gov (United States)

    2010-10-01

    ... sampling methods. 11.64 Section 11.64 Public Lands: Interior Office of the Secretary of the Interior... sampling methods. (a) General. (1) The guidance provided in this section shall be followed for selecting.... (3) When selecting testing and sampling methods, only those methodologies shall be selected: (i)...

  9. 40 CFR 80.8 - Sampling methods for gasoline and diesel fuel.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Sampling methods for gasoline and... PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES General Provisions § 80.8 Sampling methods for gasoline and diesel fuel. The sampling methods specified in this section shall be used to collect...

  10. GENERALIZED RATIO AND PRODUCT METHODS OF ESTIMATION IN SURVEY SAMPLING

    Directory of Open Access Journals (Sweden)

    Housila P. Singh

    2011-04-01

    Full Text Available This paper introduces some generalized ratio and product methods of estimation for estimating the population total Y. In addition to many Srivenkataramana and Tracy (1979 estimators are shown as members of the proposed estimators. The properties of the suggested estimators have been studied and merits are examined through numerical illustration

  11. Ant colony optimization as a method for strategic genotype sampling.

    Science.gov (United States)

    A simulation study was carried out to develop an alternative method of selecting animals to be genotyped. Simulated pedigrees included 5000 animals, each assigned genotypes for a bi-allelic single nucleotide polymorphism (SNP) based on assumed allelic frequencies of 0.7/ 0.3 and 0.5/0.5. In addition...

  12. Effect of sample preparation methods on photometric determination of the tellurium and cobalt content in the samples of copper concentrates

    Directory of Open Access Journals (Sweden)

    Viktoriya Butenko

    2016-03-01

    Full Text Available Methods of determination of cobalt and nickel in copper concentrates currently used in factory laboratories are very labor intensive and time consuming. The limiting stage of the analysis is preliminary chemical sample preparation. Carrying out the decomposition process of industrial samples with concentrated mineral acids in open systems does not allow to improve the metrological characteristics of the methods, for this reason improvement the methods of sample preparation is quite relevant and has a practical interest. The work was dedicated to the determination of the optimal conditions of preliminary chemical preparation of copper concentrate samples for the subsequent determination of cobalt and tellurium in the obtained solution using tellurium-spectrophotometric method. Decomposition of the samples was carried out by acid dissolving in individual mineral acids and their mixtures by heating in an open system as well as by using ultrasonification and microwave radiation in a closed system. In order to select the optimal conditions for the decomposition of the samples in a closed system the phase contact time and ultrasonic generator’s power were varied. Intensification of the processes of decomposition of copper concentrates with nitric acid (1:1, ultrasound and microwave radiation allowed to transfer quantitatively cobalt and tellurium into solution spending 20 and 30 min respectively. This reduced the amount of reactants used and improved the accuracy of determination by running the process in strictly identical conditions.

  13. Some preconcentration methods for water sample analysis by XRF

    International Nuclear Information System (INIS)

    Multi-elements preconcentration methods of some elements were applied. Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb were determined in water after their precipitation with one of the following organic reagents: NaDDTC, APDC, and Oxine/Activate Carbon, while Sr, Rb and Mo were determined after their precipitation with inorganic tungstophosphate compound (HPC-2:17 system). In terns of reproducibility most values was good except some cases. (author). 98 refs., 15 tabs., 12 figs

  14. The OCD Collaborative Genetics Study: Methods and Sample Description

    OpenAIRE

    Samuels, Jack F.; Riddle, Mark A.; Greenberg, Benjamin D.; Fyer, Abby J.; McCracken, James T; Rauch, Scott L.; Murphy, Dennis L.; Grados, Marco A.; Pinto, Anthony; Knowles, James A.; Piacentini, John; Cannistraro, Paul A.; Cullen, Bernadette; Bienvenu, O. Joseph; Rasmussen, Steven A.

    2006-01-01

    Results from twin and family studies suggest that obsessive-compulsive disorder (OCD) may be transmitted in families but, to date, genes for the disorder have not been identified. The OCD Collaborative Genetics Study (OCGS) is a six-site collaborative genetic linkage study of OCD. Specimens and blinded clinical data will be made available through the National Institute of Mental Health (NIMH) cell repository. In this initial report, we describe the methods of the study and present clinical ch...

  15. Importance sampling approach for the nonstationary approximation error method

    International Nuclear Information System (INIS)

    The approximation error approach has previously been proposed to handle modelling, numerical and computational errors. This approach has been developed both for stationary and nonstationary inverse problems (Kalman filtering). The key idea of the approach is to compute the approximate statistics of the errors over the distribution of all unknowns and uncertainties and carry out approximative marginalization with respect to these errors. In nonstationary problems, however, information is accumulated over time, and the initial uncertainties may turn out to have been exaggerated. In this paper, we propose an algorithm with which the approximation error statistics can be updated during the accumulation of measurement information. The proposed algorithm is based on importance sampling. The recursions that are proposed here are, however, based on the (extended) Kalman filter and therefore do not employ the often exceedingly heavy computational load of particle filtering. As a computational example, we study an estimation problem that is related to a convection–diffusion problem in which the velocity field is not accurately specified

  16. Random Sampling of Quantum States: a Survey of Methods. And Some Issues Regarding the Overparametrized Method

    Science.gov (United States)

    Maziero, Jonas

    2015-12-01

    The numerical generation of random quantum states (RQS) is an important procedure for investigations in quantum information science. Here, we review some methods that may be used for performing that task. We start by presenting a simple procedure for generating random state vectors, for which the main tool is the random sampling of unbiased discrete probability distributions (DPD). Afterwards, the creation of random density matrices is addressed. In this context, we first present the standard method, which consists in using the spectral decomposition of a quantum state for getting RQS from random DPDs and random unitary matrices. In the sequence, the Bloch vector parametrization method is described. This approach, despite being useful in several instances, is not in general convenient for RQS generation. In the last part of the article, we regard the overparametrized method (OPM) and the related Ginibre and Bures techniques. The OPM can be used to create random positive semidefinite matrices with unit trace from randomly produced general complex matrices in a simple way that is friendly for numerical implementations. We consider a physically relevant issue related to the possible domains that may be used for the real and imaginary parts of the elements of such general complex matrices. Subsequently, a too fast concentration of measure in the quantum state space that appears in this parametrization is noticed.

  17. Random sampling of quantum states: a survey of methods and some issues regarding the Overparametrized Method

    Energy Technology Data Exchange (ETDEWEB)

    Maziero, Jonas, E-mail: jonas.maziero@ufsm.br [Universidade Federal de Santa Maria (UFSM), Santa Maria, RS (Brazil). Dept. de Fisica

    2015-12-15

    The numerical generation of random quantum states (RQS) is an important procedure for investigations in quantum information science. Here, we review some methods that may be used for performing that task. We start by presenting a simple procedure for generating random state vectors, for which the main tool is the random sampling of unbiased discrete probability distributions (DPD). Afterwards, the creation of random density matrices is addressed. In this context, we first present the standard method, which consists in using the spectral decomposition of a quantum state for getting RQS from random DPDs and random unitary matrices. In the sequence, the Bloch vector parametrization method is described. This approach, despite being useful in several instances, is not in general convenient for RQS generation. In the last part of the article, we regard the overparametrized method (OPM) and the related Ginibre and Bures techniques. The OPM can be used to create random positive semidefinite matrices with unit trace from randomly produced general complex matrices in a simple way that is friendly for numerical implementations. We consider a physically relevant issue related to the possible domains that may be used for the real and imaginary parts of the elements of such general complex matrices. Subsequently, a too fast concentration of measure in the quantum state space that appears in this parametrization is noticed. (author)

  18. Random sampling of quantum states: a survey of methods and some issues regarding the Overparametrized Method

    International Nuclear Information System (INIS)

    The numerical generation of random quantum states (RQS) is an important procedure for investigations in quantum information science. Here, we review some methods that may be used for performing that task. We start by presenting a simple procedure for generating random state vectors, for which the main tool is the random sampling of unbiased discrete probability distributions (DPD). Afterwards, the creation of random density matrices is addressed. In this context, we first present the standard method, which consists in using the spectral decomposition of a quantum state for getting RQS from random DPDs and random unitary matrices. In the sequence, the Bloch vector parametrization method is described. This approach, despite being useful in several instances, is not in general convenient for RQS generation. In the last part of the article, we regard the overparametrized method (OPM) and the related Ginibre and Bures techniques. The OPM can be used to create random positive semidefinite matrices with unit trace from randomly produced general complex matrices in a simple way that is friendly for numerical implementations. We consider a physically relevant issue related to the possible domains that may be used for the real and imaginary parts of the elements of such general complex matrices. Subsequently, a too fast concentration of measure in the quantum state space that appears in this parametrization is noticed. (author)

  19. A sampling method for conducting relocation studies with freshwater mussels

    Science.gov (United States)

    Waller, D.L.; Rach, J.J.; Cope, W.G.; Luoma, J.A.

    1993-01-01

    Low recovery of transplanted mussels often prevents accurate estimates of survival. We developed a method that provided a high recovery of transplanted mussels and allowed for a reliable assessment of mortality. A 3 x 3 m polyvinyl chloride (PVC) pipe grid was secured to the sediment with iron reinforcing bars. The grid was divided into nine 1-m super(2) segments and each treatment segment, was stocked with 100 marked mussels. The recovery of mussels after six months exceeded 80% in all but one treatment group.

  20. A new resampling method for sampling designs without replacement: the doubled half bootstrap

    OpenAIRE

    Antal, Erika; Tillé, Yves

    2016-01-01

    A new and very fast method of bootstrap for sampling without replacement from a finite population is proposed. This method can be used to estimate the variance in sampling with unequal inclusion probabilities and does not require artificial populations or utilization of bootstrap weights. The bootstrap samples are directly selected from the original sample. The bootstrap procedure contains two steps: in the first step, units are selected once with Poisson sampling using the same inclusion pro...

  1. Determination of methylmercury in marine biota samples: method validation.

    Science.gov (United States)

    Carrasco, Luis; Vassileva, Emilia

    2014-05-01

    Regulatory authorities are expected to measure concentration of contaminants in foodstuffs, but the simple determination of total amount cannot be sufficient for fully judging its impact on the human health. In particular, the methylation of metals generally increases their toxicity; therefore validated analytical methods producing reliable results for the assessment of methylated species are highly needed. Nowadays, there is no legal limit for methylmercury (MeHg) in food matrices. Hence, no standardized method for the determination of MeHg exists within the international jurisdiction. Contemplating the possibility of a future legislative limit, a method for low level determination of MeHg in marine biota matrixes, based on aqueous-phase ethylation followed by purge and trap and gas chromatography (GC) coupled to pyrolysis-atomic fluorescence spectrometry (Py-AFS) detection, has been developed and validated. Five different extraction procedures, namely acid and alkaline leaching assisted by microwave and conventional oven heating, as well as enzymatic digestion, were evaluated in terms of their efficiency to extract MeHg from Scallop soft tissue IAEA-452 Certified Reference Material. Alkaline extraction with 25% (w/w) KOH in methanol, microwave-assisted extraction (MAE) with 5M HCl and enzymatic digestion with protease XIV yielded the highest extraction recoveries. Standard addition or the introduction of a dilution step were successfully applied to overcome the matrix effects observed when microwave-assisted extraction using 25% (w/w) KOH in methanol or 25% (w/v) aqueous TMAH were used. ISO 17025 and Eurachem guidelines were followed to perform the validation of the methodology. Accordingly, blanks, selectivity, calibration curve, linearity (0.9995), working range (1-800pg), recovery (97%), precision, traceability, limit of detection (0.45pg), limit of quantification (0.85pg) and expanded uncertainty (15.86%, k=2) were assessed with Fish protein Dorm-3 Certified

  2. Determination of optimal sampling times for a two blood sample clearance method using (51)Cr-EDTA in cats.

    Science.gov (United States)

    Vandermeulen, Eva; De Sadeleer, Carlos; Piepsz, Amy; Ham, Hamphrey R; Dobbeleir, André A; Vermeire, Simon T; Van Hoek, Ingrid M; Daminet, Sylvie; Slegers, Guido; Peremans, Kathelijne Y

    2010-08-01

    Estimation of the glomerular filtration rate (GFR) is a useful tool in the evaluation of kidney function in feline medicine. GFR can be determined by measuring the rate of tracer disappearance from the blood, and although these measurements are generally performed by multi-sampling techniques, simplified methods are more convenient in clinical practice. The optimal times for a simplified sampling strategy with two blood samples (2BS) for GFR measurement in cats using plasma (51)chromium ethylene diamine tetra-acetic acid ((51)Cr-EDTA) clearance were investigated. After intravenous administration of (51)Cr-EDTA, seven blood samples were obtained in 46 cats (19 euthyroid and 27 hyperthyroid cats, none with previously diagnosed chronic kidney disease (CKD)). The plasma clearance was then calculated from the seven point blood kinetics (7BS) and used for comparison to define the optimal sampling strategy by correlating different pairs of time points to the reference method. Mean GFR estimation for the reference method was 3.7+/-2.5 ml/min/kg (mean+/-standard deviation (SD)). Several pairs of sampling times were highly correlated with this reference method (r(2) > or = 0.980), with the best results when the first sample was taken 30 min after tracer injection and the second sample between 198 and 222 min after injection; or with the first sample at 36 min and the second at 234 or 240 min (r(2) for both combinations=0.984). Because of the similarity of GFR values obtained with the 2BS method in comparison to the values obtained with the 7BS reference method, the simplified method may offer an alternative for GFR estimation. Although a wide range of GFR values was found in the included group of cats, the applicability should be confirmed in cats suspected of renal disease and with confirmed CKD. Furthermore, although no indications of age-related effect were found in this study, a possible influence of age should be included in future studies. PMID:20452793

  3. Effects of Sampling Methods on Prediction Quality. The Case of Classifying Land Cover Using Decision Trees

    OpenAIRE

    Hochreiter, Ronald; Waldhauser, Christoph

    2014-01-01

    Clever sampling methods can be used to improve the handling of big data and increase its usefulness. The subject of this study is remote sensing, specifically airborne laser scanning point clouds representing different classes of ground cover. The aim is to derive a supervised learning model for the classification using CARTs. In order to measure the effect of different sampling methods on the classification accuracy, various experiments with varying types of sampling methods, sample sizes, a...

  4. Method for sampling nuclear fuel pellets with a robot gripper

    International Nuclear Information System (INIS)

    This patent describes a method of gently burrowing angularly displaced gripping fingers into a stack of nuclear fuel pellets and grasping a pellet located at a predetermined depth in the stack. It comprises: lowering the fingers into the stack of pellets toward the predetermined depth therein; rotating the fingers in a first direction relative to the stack and at a first predetermined speed concurrently as the fingers are being lowered into the stack; pausing the lowering of the fingers; rotating the fingers in a second direction opposite to the first direction relative to the stack and at a second predetermined speed faster than the first speed concurrently as the fingers are paused; repeating first four steps until the desired predetermined depth is reached; and closing the fingers upon reaching the predetermined depth to grasp a pellet located at the depth in the stack of pellets

  5. DOE financial assurance presentation

    International Nuclear Information System (INIS)

    The presentation topic is California's approach to license application review in meeting financial assurances for the proposed Ward Valley site. The purpose of the presentation is to provide information on specific financial assurance provisions contained in 10 CFR Part 61 and how California intends to satisfy those requirements. Also, as rate setter, California intends to demonstrate how it will assure allowable costs to the rate base though a financial prudency review. The key provisions of financial assurance are: 10 CFR Section 61.61 - This provision requires an applicant to demonstrate its ability to finance licensed activities; 10 CFR Section 61.62 - This provision requires an applicant to provide assurance that sufficient funds will be available for site closure and stabilization; and 10 CFR Section 61.63 - This provision requires an applicant to provide 'a copy of a binding arrangement, such as a lease, between the applicant and the disposal site owner, so that sufficient funds will be available to cover the costs of the institutional control period.' To assist California in its determination of financial assurance compliance to be demonstrated by the applicant for Part 61 requirements, is NUREG guidance document 1199 'Standard Format and Content of a License Application for a Low-Level Radioactive Waste (LLRW) Disposal Facility.' The detailed financial assurance provisions of NUREG 1199 are then embodied in NUREG 1200, 'Standard Review Plant for the Review of a License Application for a LLRW Disposal Facility.'

  6. Software quality assurance handbook

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    There are two important reasons for Software Quality Assurance (SQA) at Allied-Signal Inc., Kansas City Division (KCD): First, the benefits from SQA make good business sense. Second, the Department of Energy has requested SQA. This handbook is one of the first steps in a plant-wide implementation of Software Quality Assurance at KCD. The handbook has two main purposes. The first is to provide information that you will need to perform software quality assurance activities. The second is to provide a common thread to unify the approach to SQA at KCD. 2 figs.

  7. Quality Assurance in Radiotherapy

    Science.gov (United States)

    Mckenzie, Alan

    A common feature of the Radiotherapy Centres where there have been major accidents involving incorrect radiotherapy treatment is that they did not operate good Quality Assurance systems. A Quality Assurance system is sometimes called a Quality Management system, and it is designed to give assurance that quality standards are being met. One of the "spin offs" from operating a Quality Management system is that it reduces the likelihood of a radiotherapy accident. A detailed account of how to set up a quality system in radiotherapy has been given in an ESTRO booklet.2

  8. The OCD collaborative genetics study: methods and sample description.

    Science.gov (United States)

    Samuels, Jack F; Riddle, Mark A; Greenberg, Benjamin D; Fyer, Abby J; McCracken, James T; Rauch, Scott L; Murphy, Dennis L; Grados, Marco A; Pinto, Anthony; Knowles, James A; Piacentini, John; Cannistraro, Paul A; Cullen, Bernadette; Bienvenu, O Joseph; Rasmussen, Steven A; Pauls, David L; Willour, Virginia L; Shugart, Yin Y; Liang, Kung-yee; Hoehn-Saric, Rudolf; Nestadt, Gerald

    2006-04-01

    Results from twin and family studies suggest that obsessive-compulsive disorder (OCD) may be transmitted in families but, to date, genes for the disorder have not been identified. The OCD Collaborative Genetics Study (OCGS) is a six-site collaborative genetic linkage study of OCD. Specimens and blinded clinical data will be made available through the National Institute of Mental Health (NIMH) cell repository. In this initial report, we describe the methods of the study and present clinical characteristics of affected individuals for researchers interested in this valuable resource for genetic studies of OCD. The project clinically evaluated and collected blood specimens from 238 families containing 299 OCD-affected sibling pairs and their parents, and additional affected relative pairs, for a genome-wide linkage study. Of the 999 individuals interviewed to date, 624 were diagnosed with "definite" OCD. The mean age of subjects was 36 years (range 7-95). The majority of affected individuals (66%) were female. The mean age at onset of obsessive-compulsive symptoms was 9.5 years. Specific mood disorders, anxiety disorders, eating disorders, and skin picking were more prevalent in female cases, whereas tics, Tourette disorder, and alcohol dependence were more prevalent in male cases. Compared to "definite" cases of OCD, "probable" cases (n = 82) had, on average, later age at onset of obsessive-compulsive symptoms, lower severity score, and fewer numbers of different categories of obsessions and compulsions, and they were less likely to have received treatment for their symptoms. PMID:16511842

  9. Requirement Assurance: A Verification Process

    Science.gov (United States)

    Alexander, Michael G.

    2011-01-01

    Requirement Assurance is an act of requirement verification which assures the stakeholder or customer that a product requirement has produced its "as realized product" and has been verified with conclusive evidence. Product requirement verification answers the question, "did the product meet the stated specification, performance, or design documentation?". In order to ensure the system was built correctly, the practicing system engineer must verify each product requirement using verification methods of inspection, analysis, demonstration, or test. The products of these methods are the "verification artifacts" or "closure artifacts" which are the objective evidence needed to prove the product requirements meet the verification success criteria. Institutional direction is given to the System Engineer in NPR 7123.1A NASA Systems Engineering Processes and Requirements with regards to the requirement verification process. In response, the verification methodology offered in this report meets both the institutional process and requirement verification best practices.

  10. A Typology of Mixed Methods Sampling Designs in Social Science Research

    Science.gov (United States)

    Onwuegbuzie, Anthony J.; Collins, Kathleen M. T.

    2007-01-01

    This paper provides a framework for developing sampling designs in mixed methods research. First, we present sampling schemes that have been associated with quantitative and qualitative research. Second, we discuss sample size considerations and provide sample size recommendations for each of the major research designs for quantitative and…

  11. Comparison of chlorzoxazone one-sample methods to estimate CYP2E1 activity in humans

    DEFF Research Database (Denmark)

    Kramer, Iza; Dalhoff, Kim; Clemmesen, Jens O;

    2003-01-01

    OBJECTIVE: Comparison of a one-sample with a multi-sample method (the metabolic fractional clearance) to estimate CYP2E1 activity in humans. METHODS: Healthy, male Caucasians ( n=19) were included. The multi-sample fractional clearance (Cl(fe)) of chlorzoxazone was compared with one-time-point cl...

  12. TASK TECHNICAL AND QUALITY ASSURANCE PLAN FOR THE CHARACTERIZATION AND LEACHING OF A THERMOWELL AND CONDUCTIVITY PROBE PIPE SAMPLE FROM TANK 48H

    International Nuclear Information System (INIS)

    plan outlines the proposed method of analysis and testing to estimate (1) the thickness of the solid deposit, (2) chemical composition of the deposits and (3) the leaching behavior of the solid deposits in inhibited water (IW) and in Tank 48H aggregate solution

  13. Healthcare Software Assurance

    OpenAIRE

    Cooper, Jason G.; Pauley, Keith A.

    2006-01-01

    Software assurance is a rigorous, lifecycle phase-independent set of activities which ensure completeness, safety, and reliability of software processes and products. This is accomplished by guaranteeing conformance to all requirements, standards, procedures, and regulations. These assurance processes are even more important when coupled with healthcare software systems, embedded software in medical instrumentation, and other healthcare-oriented life-critical systems. The current Food and Dru...

  14. RAVEN Quality Assurance Activities

    International Nuclear Information System (INIS)

    This report discusses the quality assurance activities needed to raise the Quality Level of Risk Analysis in a Virtual Environment (RAVEN) from Quality Level 3 to Quality Level 2. This report also describes the general RAVEN quality assurance activities. For improving the quality, reviews of code changes have been instituted, more parts of testing have been automated, and improved packaging has been created. For upgrading the quality level, requirements have been created and the workflow has been improved.

  15. RAVEN Quality Assurance Activities

    Energy Technology Data Exchange (ETDEWEB)

    Cogliati, Joshua Joseph [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    This report discusses the quality assurance activities needed to raise the Quality Level of Risk Analysis in a Virtual Environment (RAVEN) from Quality Level 3 to Quality Level 2. This report also describes the general RAVEN quality assurance activities. For improving the quality, reviews of code changes have been instituted, more parts of testing have been automated, and improved packaging has been created. For upgrading the quality level, requirements have been created and the workflow has been improved.

  16. Quality assurance in radiotherapy

    International Nuclear Information System (INIS)

    Quality assurance in the management of a patient receiving radiation therapy and the role of the radiation oncologist and medical physicist in this process is described. The constraints on available personnel are recognised and the need for further education resources and IAEA activities in education for both groups described. IAEA activities in the clinical and dosimetric aspects and the resultant publications and education have contributed to a culture of quality assurance. (author)

  17. 222Rn in water: A comparison of two sample collection methods and two sample transport methods, and the determination of temporal variation in North Carolina ground water

    International Nuclear Information System (INIS)

    Objectives of this field experiment were: (1) determine whether there was a statistically significant difference between the radon concentrations of samples collected by EPA's standard method, using a syringe, and an alternative, slow-flow method; (2) determine whether there was a statistically significant difference between the measured radon concentrations of samples mailed vs samples not mailed; and (3) determine whether there was a temporal variation of water radon concentration over a 7-month period. The field experiment was conducted at 9 sites, 5 private wells, and 4 public wells, at various locations in North Carolina. Results showed that a syringe is not necessary for sample collection, there was generally no significant radon loss due to mailing samples, and there was statistically significant evidence of temporal variations in water radon concentrations

  18. Sampling methods. A survey of methods in use in the Nordic countries

    International Nuclear Information System (INIS)

    This report is a survey of sampling techniques currently in use for radioactivity measurements in the Nordic countries, but restricted to sampling techniques for pasture, soil and deposition in emergency situations. It is found that the participating laboratories apply similar sampling procedures for pasture, including cutting height and size of sampled areas. Soil samples are generally taken by some sort of corer of different diameter. The number of cores taken varies, different sampling patterns are used, and pooling of the samples is done by some of the laboratories. The analysis of pasture and of soil is made with Nal-detectors or by high-resolution gamma spectrometry on fresh or dried samples. Precipitation collectors of a range of sizes are used to determine the activity concentration in precipitation and of dry deposited radionuclides. The analysis is made with high-resolution gamma-spectrometry, either directly on a water sample or on ion exchange resins. (au)

  19. Sampling methods. A survey of methods in use in the Nordic countries

    Energy Technology Data Exchange (ETDEWEB)

    Isaksson, M. [Goeteborg Univ., Dept. of Radiation Physics, Goeteborg (Sweden)

    2000-10-01

    This report is a survey of sampling techniques currently in use for radioactivity measurements in the Nordic countries, but restricted to sampling techniques for pasture, soil and deposition in emergency situations. It is found that the participating laboratories apply similar sampling procedures for pasture, including cutting height and size of sampled areas. Soil samples are generally taken by some sort of corer of different diameter. The number of cores taken varies, different sampling patterns are used, and pooling of the samples is done by some of the laboratories. The analysis of pasture and of soil is made with Nal-detectors or by high-resolution gamma spectrometry on fresh or dried samples. Precipitation collectors of a range of sizes are used to determine the activity concentration in precipitation and of dry deposited radionuclides. The analysis is made with high-resolution gamma-spectrometry, either directly on a water sample or on ion exchange resins. (au)

  20. Composite sampling a novel method to accomplish observational economy in environmental studies

    CERN Document Server

    Patil, Ganapati P; Taillie, Charles

    2010-01-01

    This monograph provides a comprehensive statistical account of composite sampling as an ingenious environmental sampling method to help accomplish observational economy in a variety of environmental and ecological studies.

  1. Practical Method for Extraction of PCR-Quality DNA from Environmental Soil Samples ▿ †

    OpenAIRE

    Kelly A Fitzpatrick; Kersh, Gilbert J.; Massung, Robert F.

    2010-01-01

    Methods for the extraction of PCR-quality DNA from environmental soil samples by using pairs of commercially available kits were evaluated. Coxiella burnetii DNA was detected in spiked soil samples at

  2. Impact of the sampling method and chilling on the Salmonella recovery from pig carcasses.

    Science.gov (United States)

    Vanantwerpen, Gerty; De Zutter, Lieven; Berkvens, Dirk; Houf, Kurt

    2016-09-01

    Differences in recovery of Salmonella on pig carcasses using non-destructive and destructive sampling methods is not well understood in respect to the chilling processes applied in slaughterhouses. Therefore, in two slaughterhouses, four strains at two different concentrations were inoculated onto pork skin. Inoculated skin samples were sampled before and after chilling with two sampling methods: swabbing and destruction. Both slaughterhouses were visited three times and all tests were performed in triplicate. All samples were analysed using the ISO-method and recovered isolates were confirmed by PFGE. The chilling system (fast or conventional cooling) nor the sampling step (before and after chilling) did not significantly influence the recovery of Salmonella. However, swabbing after chilling leads to an underestimation of the real number of contaminated carcasses. Therefore, destructive sampling is the more designated sampling method after chilling. PMID:27236225

  3. Sample Size Determination: A Comparison of Attribute, Continuous Variable, and Cell Size Methods.

    Science.gov (United States)

    Clark, Philip M.

    1984-01-01

    Describes three methods of sample size determination, each having its use in investigation of social science problems: Attribute method; Continuous Variable method; Galtung's Cell Size method. Statistical generalization, benefits of cell size method (ease of use, trivariate analysis and trichotyomized variables), and choice of method are…

  4. [METHODS AND TECHNOLOGIES OF HEALTH RISK ANALYSIS IN THE SYSTEM OF THE STATE MANAGEMENT UNDER ASSURANCE OF THE SANITATION AND EPIDEMIOLOGICAL WELFARE OF POPULATION].

    Science.gov (United States)

    Zaĭtseva, N V; Popova, A Iu; Maĭ, I V; Shur, P Z

    2015-01-01

    The methodology of the analysis of health risk at the present stage of development of Russian society is in-demand at all levels of government management. In conjunction with the methods of mathematical modeling, spatial-temporal analysis and economic tools the risk assessment in the analysis of the situation makes it possible to determine the level of safety of the population, workers and consumers, to select prior resources, and threat factors as a point for exertion efforts. At the planning stage risk assessment is a basis for the establishment of most effective measures for the minimization of hazard and dangers. At the realization stage the methodology allows to estimate the efficiency of measures; at the control and supervision phase it permits to select out priorities for the concentration of efforts on the objects of maximal health risk for population. Risk assessments, including the elements of evolutionary modeling, are incorporated in the system of state hygienic regulation, the formation of evidence base of harm to health, the organization of control and supervisory activities. This allows you to harmonize the domestic legal framework with ternational legal requirements and ultimately enhances the credibility of the Russian data on the safety of the environment products and services. There is seemed to be actual the further assignment of enforcement of methodology of health risk analysis in the field of assurance of sanitary and epidemiological well-being and health of employers; he development of informational and analytical base in the part of the establishment of models of dependencies "exposure-response" for different types and levels of exposure and risk contingents; the accuracy enhancement of estimations of exposure; improvement of the economic aspects of health risk analysis and forecasting of measures aimed at mitigation of the losses associated with the negative impact of manifold factors on the health of citizens. PMID:26155657

  5. Performance assurance program plan

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, B.H.

    1997-11-06

    B and W Protec, Inc. (BWP) is responsible for implementing the Performance Assurance Program for the Project Hanford Management Contract (PHMC) in accordance with DOE Order 470.1, Safeguards and Security Program (DOE 1995a). The Performance Assurance Program applies to safeguards and security (SAS) systems and their essential components (equipment, hardware, administrative procedures, Protective Force personnel, and other personnel) in direct support of Category I and H special nuclear material (SNM) protection. Performance assurance includes several Hanford Site activities that conduct performance, acceptance, operability, effectiveness, and validation tests. These activities encompass areas of training, exercises, quality assurance, conduct of operations, total quality management, self assessment, classified matter protection and control, emergency preparedness, and corrective actions tracking and trending. The objective of the Performance Assurance Program is to capture the critical data of the tests, training, etc., in a cost-effective, manageable program that reflects the overall effectiveness of the program while minimizing operational impacts. To aid in achieving this objective, BWP will coordinate the Performance Assurance Program for Fluor Daniel Hanford, Inc. (FDH) and serve as the central point for data collection.

  6. Comparison of flammability of litters sampled according to two different methods

    OpenAIRE

    Ganteaume, A.; Jappiot, M.; Curt, T.; Lampin, C.; Borgniet, L.

    2012-01-01

    In laboratory conditions, reconstructed or intact litter samples can be used to assess the flammability of dead surface fuels but the sampling method could affect litter flammability results. To assess this effect, samples of litters were collected in south-eastern France, according to two different methods previously used in other studies, one keeping intact the structure of litter layers (intact litter) and the other using mainly the surface litter layer to reconstruct the litter sample (re...

  7. Fast egg collection method greatly improves randomness of egg sampling in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Schou, Mads Fristrup

    2013-01-01

    When obtaining samples for population genetic studies, it is essential that the sampling is random. For Drosophila, one of the crucial steps in sampling experimental flies is the collection of eggs. Here an egg collection method is presented, which randomizes the eggs in a water column and...... samples between the two methods was assessed. The method presented here was superior to the traditional method. Only 14% of the samples had a standard deviation higher than expected, as compared with 58% in the traditional method. To reduce bias in the estimation of the variance and the mean of a trait...... diminishes environmental variance. This method was compared with a traditional egg collection method where eggs are collected directly from the medium. Within each method the observed and expected standard deviations of egg-to-adult viability were compared, whereby the difference in the randomness of the...

  8. Estimation and Comparison of Immunization Coverage under Different Sampling Methods for Health Surveys

    OpenAIRE

    Nath, D. C.; Patowari, B.

    2014-01-01

    Immunization currently averts an estimated 2-3 million deaths every year in all age groups. Hepatitis B is a major public health problem worldwide. In this study, the estimates of hepatitis B vaccine coverage are compared among three sampling plans namely, 30×30 sampling and 30×7 sampling method under cluster sampling and systematic random sampling schemes. The data has been taken from the survey “Comparison of Two Survey Methodologies to Estimate Total Vaccination Coverage” sponsored by Indi...

  9. Comparison of individual and pooled sampling methods for detecting bacterial pathogens of fish

    Science.gov (United States)

    Mumford, Sonia; Patterson, Chris; Evered, J.; Brunson, Ray; Levine, J.; Winton, J.

    2005-01-01

    Examination of finfish populations for viral and bacterial pathogens is an important component of fish disease control programs worldwide. Two methods are commonly used for collecting tissue samples for bacteriological culture, the currently accepted standards for detection of bacterial fish pathogens. The method specified in the Office International des Epizooties Manual of Diagnostic Tests for Aquatic Animals permits combining renal and splenic tissues from as many as 5 fish into pooled samples. The American Fisheries Society (AFS) Blue Book/US Fish and Wildlife Service (USFWS) Inspection Manual specifies the use of a bacteriological loop for collecting samples from the kidney of individual fish. An alternative would be to more fully utilize the pooled samples taken for virology. If implemented, this approach would provide substantial savings in labor and materials. To compare the relative performance of the AFS/USFWS method and this alternative approach, cultures of Yersinia ruckeri were used to establish low-level infections in groups of rainbow trout (Oncorhynchus mykiss) that were sampled by both methods. Yersinia ruckeri was cultured from 22 of 37 groups by at least 1 method. The loop method yielded 18 positive groups, with 1 group positive in the loop samples but negative in the pooled samples. The pooled samples produced 21 positive groups, with 4 groups positive in the pooled samples but negative in the loop samples. There was statistically significant agreement (Spearman coefficient 0.80, P sampling methods to permit detection of low-level bacterial infections of rainbow trout.

  10. Good manufacturing practice - quality assurance programs

    International Nuclear Information System (INIS)

    The concept of good manufacturing practice (GMP) in the medical device industry requires the use of controlled methods and equipment in performing each step in the device manufacturing process. Quality assurance programs are used to maintain compliance with GMP requirements by prescribing the operating and control procedures to be used. The specific elements of a quality assurance program for the radiation sterilization of medical devices are described. (author)

  11. Identification of Legionella spp. in Environmental Water Samples by ScanVIT-Legionella™ Method in Spain

    OpenAIRE

    Gruas, Cristina; Álvarez, Isidro; Lara, Carlos; García, Cristina Belén; Savva, Demetris; Arruga, M. Victoria

    2013-01-01

    Rapid and more sensitive methods for the detection and quantification of viable Legionella cells have been developed. In this paper, a comparative analysis of environmental water samples using the ScanVIT-Legionella™ method and the traditional “gold standard” method of culturing is realised indicating the usefulness of the ScanVIT method. The ScanVIT-Legionella™ method was performed on environmental water samples from different locations of Huesca region (Spain). Legionella micro-colonies sho...

  12. A Direct Bootstrap Method for Complex Sampling Designs From a Finite Population

    OpenAIRE

    Antal, Erika; Tillé, Yves

    2016-01-01

    In complex designs, classical bootstrap methods result in a biased variance estimator when the sampling design is not taken into account. Resampled units are usually rescaled or weighted in order to achieve unbiasedness in the linear case. In the present article, we propose novel resampling methods that may be directly applied to variance estimation. These methods consist of selecting subsamples under a completely different sampling scheme from that which generated the original sample, whic...

  13. Evaluation of seven aquatic sampling methods for amphibians and other aquatic fauna

    Science.gov (United States)

    Gunzburger, M.S.

    2007-01-01

    To design effective and efficient research and monitoring programs researchers must have a thorough understanding of the capabilities and limitations of their sampling methods. Few direct comparative studies exist for aquatic sampling methods for amphibians. The objective of this study was to simultaneously employ seven aquatic sampling methods in 10 wetlands to compare amphibian species richness and number of individuals detected with each method. Four sampling methods allowed counts of individuals (metal dipnet, D-frame dipnet, box trap, crayfish trap), whereas the other three methods allowed detection of species (visual encounter, aural, and froglogger). Amphibian species richness was greatest with froglogger, box trap, and aural samples. For anuran species, the sampling methods by which each life stage was detected was related to relative length of larval and breeding periods and tadpole size. Detection probability of amphibians varied across sampling methods. Box trap sampling resulted in the most precise amphibian count, but the precision of all four count-based methods was low (coefficient of variation > 145 for all methods). The efficacy of the four count sampling methods at sampling fish and aquatic invertebrates was also analyzed because these predatory taxa are known to be important predictors of amphibian habitat distribution. Species richness and counts were similar for fish with the four methods, whereas invertebrate species richness and counts were greatest in box traps. An effective wetland amphibian monitoring program in the southeastern United States should include multiple sampling methods to obtain the most accurate assessment of species community composition at each site. The combined use of frogloggers, crayfish traps, and dipnets may be the most efficient and effective amphibian monitoring protocol. ?? 2007 Brill Academic Publishers.

  14. Serum chromium levels sampled with steel needle versus plastic IV cannula. Does method matter?

    DEFF Research Database (Denmark)

    Penny, Jeannette Ø; Overgaard, Søren

    2010-01-01

    causing bias. This study aimed to test that theory. METHODS: We compared serum chromium values for two sampling methods, steel needle and IV plastic cannula, as well as sampling sequence in 16 healthy volunteers. RESULTS: We found statistically significant chromium contamination from the steel needle with...... mean differences between the two methods of 0.073 ng/mL, for the first sample, and 0.033 ng/mL for the second. No difference was found between the first and second plastic sample. The first steel needle sample contained an average of 0.047 ng/mL more than the second. This difference was only borderline...... significant. CONCLUSION: The chromium contamination from the steel needle is low, and sampling method matters little in MoM populations. If using steel needles we suggest discarding the first sample....

  15. Comparison of Assurance GDS(®) MPX ID for Top STEC with Reference Culture Methods for the Detection of E. coli Top 6 STEC; Direct Confirmation of Top 6 STEC from Isolation Plates and Determination of Equivalence of PickPen(®) and FSIS OctoMACS™ Concentration Protocols.

    Science.gov (United States)

    Feldsine, Philip; Lienau, Andrew H; Shah, Khyati; Immermann, Amy; Soliven, Khanh; Kaur, Mandeep; Kerr, David E; Jucker, Markus; Hammack, Tom; Brodsky, Michael; Agin, James

    2016-03-01

    Assurance GDS(®) MPX ID for Top Shiga toxin-producing Escherichia coli (STEC; MPX ID) was validated according to the AOAC INTERNATIONAL Methods Committee Guidelines for Validation of Microbiological Methods for Foods and Environmental Surfaces as (1) a secondary screening method for specific detection of the Top 6 STEC serogroups (O26, O45, O103, O111, O121, and O145) in raw beef trim, raw ground beef, raw spinach, and on stainless steel; and (2) as a confirmatory method for the identification of pure culture isolates as Top 6 STEC. MPX ID is used in conjunction with the upfront BCS Assurance GDS MPX Top 7 STEC assay. This Performance Tested Method(SM) validation has two main parts: Method Developer studies and the Independent Laboratory study. A total of 180 samples and controls were analyzed. Results showed that MPX ID had no statistically significant differences with the reference culture methods for the detection of Top 6 STEC in the food matrixes (raw beef trim, raw ground beef, and raw spinach) and environmental sponges (stainless steel) studied. Inclusivity/exclusivity studies were also conducted. One hundred percent inclusivity among the 50 Top 6 STEC serovars tested and 100% exclusivity for the 30 non-Top 6 STEC organisms tested were demonstrated. For validation of MPX ID as a confirmatory method for isolated colonies, all inclusivity and exclusivity organisms were streaked for isolation onto five STEC plating media: modified rainbow agar, Levine's eosin-methylene blue (L-EMB) agar, rainbow agar with novobiocin and cefixime, and enterohemolysin agar with selective agents as well as trypticase soy agar with yeast extract. These isolated colonies were suspended and analyzed by Assurance GDS MPX Top 7 STEC and MPX ID. MPX ID was able to correctly confirm all inclusivity organisms from all plate types, except two STEC isolates from L-EMB agar plates only in the Independent Laboratory study. All exclusivity organisms were correctly determined by MPX ID as non

  16. Methods of sampling airborne fungi in working environments of waste treatment facilities

    Directory of Open Access Journals (Sweden)

    Kristýna Černá

    2016-03-01

    Full Text Available Objectives: The objective of the present study was to evaluate and compare the efficiency of a filter based sampling method and a high volume sampling method for sampling airborne culturable fungi present in waste sorting facilities. Material and Methods: Membrane filters method was compared with surface air system method. The selected sampling methods were modified and tested in 2 plastic waste sorting facilities. Results: The total number of colony-forming units (CFU/m3 of airborne fungi was dependent on the type of sampling device, on the time of sampling, which was carried out every hour from the beginning of the work shift, and on the type of cultivation medium (p < 0.001. Detected concentrations of airborne fungi ranged 2×102–1.7×106 CFU/m3 when using the membrane filters (MF method, and 3×102–6.4×104 CFU/m3 when using the surface air system (SAS method. Conclusions: Both methods showed comparable sensitivity to the fluctuations of the concentrations of airborne fungi during the work shifts. The SAS method is adequate for a fast indicative determination of concentration of airborne fungi. The MF method is suitable for thorough assessment of working environment contamination by airborne fungi. Therefore we recommend the MF method for the implementation of a uniform standard methodology of airborne fungi sampling in working environments of waste treatment facilities.

  17. Flight Dynamics Mission Support and Quality Assurance Process

    Science.gov (United States)

    Oh, InHwan

    1996-01-01

    This paper summarizes the method of the Computer Sciences Corporation Flight Dynamics Operation (FDO) quality assurance approach to support the National Aeronautics and Space Administration Goddard Space Flight Center Flight Dynamics Support Branch. Historically, a strong need has existed for developing systematic quality assurance using methods that account for the unique nature and environment of satellite Flight Dynamics mission support. Over the past few years FDO has developed and implemented proactive quality assurance processes applied to each of the six phases of the Flight Dynamics mission support life cycle: systems and operations concept, system requirements and specifications, software development support, operations planing and training, launch support, and on-orbit mission operations. Rather than performing quality assurance as a final step after work is completed, quality assurance has been built in as work progresses in the form of process assurance. Process assurance activities occur throughout the Flight Dynamics mission support life cycle. The FDO Product Assurance Office developed process checklists for prephase process reviews, mission team orientations, in-progress reviews, and end-of-phase audits. This paper will outline the evolving history of FDO quality assurance approaches, discuss the tailoring of Computer Science Corporations's process assurance cycle procedures, describe some of the quality assurance approaches that have been or are being developed, and present some of the successful results.

  18. Progress toward maturity of DOE methods for evaluating environmental and waste management samples

    Energy Technology Data Exchange (ETDEWEB)

    Cosby, W.C. [ed.; Goheen, S.C.; McCulloch, M. [and others

    1994-07-01

    The document DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods) has been in circulation since October 1992. DOE Methods is a living document, being updated twice each year. It contains both sampling and analytical methods in support of US Department of Energy/environmental restoration and waste management (DOE/EM) activities. Guidance on how to carry out sampling and analysis activities, focusing of EM needs, is also included in DOE Methods. This guidance applies to all aspects of sampling and analysis for EM. Methods from traditional standard methods documents often cannot provide needed characterization data because of radioactivity or complexity of the matrix. The intent of DOE Methods is to provide an alternative source of methods to meet this need. Efforts are underway to expand the use of DOE Methods throughout all DOE/EM programs. Copies of DOE Methods are available free of charge. The April 1994 update of the document includes 42 methods, of which 13 are new. In October 1994, Revision 2 of DOE Methods will be distributed. It will include additional guidance on how to plan sampling and analysis activities and will also include several new methods. DOE Methods is supported by the Laboratory Management Division of DOE. It is a vehicle for transgressing new technology for characterization capability within the environmental restoration (ER) and/or waste management (WM) community. As DOE Methods continues to evolve, its use and application will continue to grow.

  19. Progress toward maturity of DOE methods for evaluating environmental and waste management samples

    International Nuclear Information System (INIS)

    The document DOE Methods for Evaluating Environmental and Waste Management Samples (DOE Methods) has been in circulation since October 1992. DOE Methods is a living document, being updated twice each year. It contains both sampling and analytical methods in support of US Department of Energy/environmental restoration and waste management (DOE/EM) activities. Guidance on how to carry out sampling and analysis activities, focusing of EM needs, is also included in DOE Methods. This guidance applies to all aspects of sampling and analysis for EM. Methods from traditional standard methods documents often cannot provide needed characterization data because of radioactivity or complexity of the matrix. The intent of DOE Methods is to provide an alternative source of methods to meet this need. Efforts are underway to expand the use of DOE Methods throughout all DOE/EM programs. Copies of DOE Methods are available free of charge. The April 1994 update of the document includes 42 methods, of which 13 are new. In October 1994, Revision 2 of DOE Methods will be distributed. It will include additional guidance on how to plan sampling and analysis activities and will also include several new methods. DOE Methods is supported by the Laboratory Management Division of DOE. It is a vehicle for transgressing new technology for characterization capability within the environmental restoration (ER) and/or waste management (WM) community. As DOE Methods continues to evolve, its use and application will continue to grow

  20. Quality assurance in design

    International Nuclear Information System (INIS)

    Full text: Safety of the nuclear power plant depends on design, manufacturing, construction, commissioning and operation of plant. To ensure that all the constituent phases are performed as per intent, quality assurance is extremely important. NPCIL has developed a quality assurance programme for all above constituent phases for ensuring safety of public and site personnel. A topical quality assurance document at corporate level gives broad based policy document on quality assurance programme of NPCIL. For design and engineering services, a quality assurance programme has been developed based on ISO 9001 and AERB Code No. SC/QA. To ensure nuclear reactor safety, the design activities are carried out under controlled conditions which include: (i) establishment and maintenance of procedures describing how the design activities are to be carried out, (ii) assignment of design tasks to appropriately qualified and experienced personnel, (iii) compliance with codes, standards and regulatory requirements, (iv) incorporation of customer feedbacks/corrective and preventative actions, (v) compliance with quality plans and procedures., (vi) design control, (vii) proper document and data control, (viii) use of validated soft wares, (ix) review of consultants design, design documents at appropriate stages, (x) preparation, review and approval of designs and design documents by competent persons, (xi) AERB review of safety related design basis reports (DBRs), (xii) periodic internal quality audits for verifying the compliance to QA system, (xiii) periodic external audits by ISO 9001 certifying agency and NPCIL QA directorate, (xiv) Nonconformance control

  1. An improved adaptive sampling and experiment design method for aerodynamic optimization

    Directory of Open Access Journals (Sweden)

    Huang Jiangtao

    2015-10-01

    Full Text Available Experiment design method is a key to construct a highly reliable surrogate model for numerical optimization in large-scale project. Within the method, the experimental design criterion directly affects the accuracy of the surrogate model and the optimization efficient. According to the shortcomings of the traditional experimental design, an improved adaptive sampling method is proposed in this paper. The surrogate model is firstly constructed by basic sparse samples. Then the supplementary sampling position is detected according to the specified criteria, which introduces the energy function and curvature sampling criteria based on radial basis function (RBF network. Sampling detection criteria considers both the uniformity of sample distribution and the description of hypersurface curvature so as to significantly improve the prediction accuracy of the surrogate model with much less samples. For the surrogate model constructed with sparse samples, the sample uniformity is an important factor to the interpolation accuracy in the initial stage of adaptive sampling and surrogate model training. Along with the improvement of uniformity, the curvature description of objective function surface gradually becomes more important. In consideration of these issues, crowdness enhance function and root mean square error (RMSE feedback function are introduced in C criterion expression. Thus, a new sampling method called RMSE and crowdness enhance (RCE adaptive sampling is established. The validity of RCE adaptive sampling method is studied through typical test function firstly and then the airfoil/wing aerodynamic optimization design problem, which has high-dimensional design space. The results show that RCE adaptive sampling method not only reduces the requirement for the number of samples, but also effectively improves the prediction accuracy of the surrogate model, which has a broad prospects for applications.

  2. Method for sample preparation for cryoelectron microscopy (CEM) microreactor and loading platform

    NARCIS (Netherlands)

    Zandbergen, H.W.; Ahn, C.W.

    2008-01-01

    A method for sample preparation for cryoelectron microscopy (CEM), wherein the sample is held in a microreactor, wherein the conditions in the microreactor are regulated relative to the environment, wherein the sample in the microreactor is frozen according to a quench freeze process, whereupon the

  3. Methods and devices for hyperpolarising and melting NMR samples in a cryostat

    DEFF Research Database (Denmark)

    Ardenkjaer-Larsen, Jan Henrik; Axelsson, Oskar H. E.; Golman, Klaes Koppel; Wolber, Jan; Howard, Mark

    2006-01-01

    The present invention relates to devices and method for melting solid polarised sample while retaining a high level of polarisation. In an embodiment of the present invention a sample is polarised in a sample-retaining cup 9 in a strong magnetic field in a polarising means 3a, 3b, 3c in a cryostat...

  4. Multiplex biotoxin surface plasmon resonance method for marine biotoxins in algal and seawater samples

    OpenAIRE

    McNamee, E; Elliott, T.; Delahaut, P.; Campbell, K

    2013-01-01

    A multiplex surface plasmon resonance (SPR) biosensor method for the detection of paralytic shellfish poisoning (PSP) toxins, okadaic acid (and analogues) and domoic acid was developed. This method was compared to enzyme-linked immunosorbent assay (ELISA) methods. Seawater samples (n = 256) from around Europe were collected by the consortia of an EU project MIcroarrays for the Detection of Toxic Algae (MIDTAL) and evaluated using each method. A simple sample preparation procedure was develope...

  5. Generalized Bulgac-Kusnezov Methods for Sampling of the Gibbs-Boltzmann Measure

    OpenAIRE

    Leimkuhler, Benedict

    2010-01-01

    A wide family of methods is described for sampling in the canonical ensemble. The Bulgac-Kusnezov method is generalized to include a more complicated coupling structure and stochastic perturbations. It is shown that a controlled fluctuation of the potential surface or force field in a molecular model may be used as part of a sampling method (instead of the more standard friction or driving term). Numerical experiments demonstrate that the family includes methods that are effective for recover...

  6. Ionizing radiation as optimization method for aluminum detection from drinking water samples

    International Nuclear Information System (INIS)

    The presence of organic compounds in water samples is often responsible for metal complexation; depending on the analytic method, the organic fraction may dissemble the evaluation of the real values of metal concentration. Pre-treatment of the samples is advised when organic compounds are interfering agents, and thus sample mineralization may be accomplished by several chemical and/or physical methods. Here, the ionizing radiation was used as an advanced oxidation process (AOP), for sample pre-treatment before the analytic determination of total and dissolved aluminum by ICP-OES in drinking water samples from wells and spring source located at Billings dam region. Before irradiation, the spring source and wells' samples showed aluminum levels of 0.020 mg/l and 0.2 mg/l respectively; after irradiation, both samples showed a 8-fold increase of aluminum concentration. These results are discussed considering other physical and chemical parameters and peculiarities of sample sources. (author)

  7. Improved Butanol-Methanol (BUME) Method by Replacing Acetic Acid for Lipid Extraction of Biological Samples.

    Science.gov (United States)

    Cruz, Mutya; Wang, Miao; Frisch-Daiello, Jessica; Han, Xianlin

    2016-07-01

    Extraction of lipids from biological samples is a critical step in lipidomics, especially for shotgun lipidomics where lipid extracts are directly infused into a mass spectrometer. The butanol-methanol (BUME) extraction method was originally developed to extract lipids from plasma samples with 1 % acetic acid. Considering some lipids are sensitive to acidic environments, we modified this protocol by replacing acetic acid with lithium chloride solution and extended the modified extraction to tissue samples. Although no significant reduction of plasmalogen levels in the acidic BUME extracts of rat heart samples was found, the modified method was established to extract various tissue samples, including rat liver, heart, and plasma. Essentially identical profiles of the majority of lipid classes were obtained from the extracts of the modified BUME and traditional Bligh-Dyer methods. However, it was found that neither the original, nor the modified BUME method was suitable for 4-hydroxyalkenal species measurement in biological samples. PMID:27245345

  8. Vega flow assurance system

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Marit; Munaweera, Sampath

    2010-07-01

    Vega is a gas condensate field located at the west coast of Norway and developed as a tie-in to the Gjoea platform. Operator is Statoil, production startup is estimated to the end of 2010. Flow assurance challenges are high reservoir pressure and temperature, hydrate and wax control, liquid accumulation and monitoring the well/template production rates. The Vega Flow Assurance System (FAS) is a software that supports monitoring and operation of the field. The FAS is based FlowManagerTM designed for real time systems. This is a flexible tool with its own steady state multiphase- and flow assurance models. Due to the long flowlines lines and the dynamic behavior, the multiphase flow simulator OLGA is also integrated in the system. Vega FAS will be used as: - An online monitoring tool - An offline what-if simulation and validation tool - An advisory control system for well production allocation. (Author)

  9. Determination Of Heavy Metal Elements In The Environmental Samples Using Neutron Activation Analysis Method

    International Nuclear Information System (INIS)

    The environmental samples (water, soil and spinach) were analyzed using analysis activation neutron method. The aim of this research is to determine the heavy metal's pollution level in comparation with environmental standard. Samples were taken from 3 different locations, Kelurahan Papanggo, Kelurahan Sunter Agung, and Kelurahan Sunter Jaya. The samples were irradiated in the RSG-GAS's rabbit system. Samples irradiated were then measured by a gamma spectrometer. The result showed that environmental samples contained toxical heavy metal elements: Cr and As; moderate: Mn, V, and Co; and less toxical: Fe and Zn. The concentration of Cr, Co, and Zn in the soil, water and spinach samples were less than environmental standards applied

  10. Studies and applications of X-ray sampling method: Pt. 3

    International Nuclear Information System (INIS)

    The Mineralizing non-homogeneity effect in X-ray sampling was investigated with theory of mathematical statistics for the first time. A method of correcting the mineralizing non-homogeneity effect based on mathematical statistics has been developed for X-ray sampling. Theoretical evaluations and experiments have shown that the method developed is affected least by the mineralizing non-homogeneity effect

  11. Evaluation of beef trim sampling methods for detection of Shiga toxin-producing Escherichia coli (STEC)

    Science.gov (United States)

    Presence of Shiga toxin-producing Escherichia coli (STEC) is a major concern in ground beef. Several methods for sampling beef trim prior to grinding are currently used in the beef industry. The purpose of this study was to determine the efficacy of the sampling methods for detecting STEC in beef ...

  12. Sampling Methods and the Accredited Population in Athletic Training Education Research

    Science.gov (United States)

    Carr, W. David; Volberding, Jennifer

    2009-01-01

    Context: We describe methods of sampling the widely-studied, yet poorly defined, population of accredited athletic training education programs (ATEPs). Objective: There are two purposes to this study; first to describe the incidence and types of sampling methods used in athletic training education research, and second to clearly define the…

  13. Conditional Modeling and the Jitter Method of Spike Re-sampling: Supplement

    OpenAIRE

    Amarasingham, Asohan; Harrison, Matthew T.; Hatsopoulos, Nicholas G.; Geman, Stuart

    2011-01-01

    This technical report accompanies the manuscript "Conditional Modeling and the Jitter Method of Spike Re-sampling." It contains further details, comments, references, and equations concerning various simulations and data analyses presented in that manuscript, as well as a self-contained Mathematical Appendix that provides a formal treatment of jitter-based spike re-sampling methods.

  14. Comparison of Three Insect Sampling Methods in Sweetpotato Foliage in Mississippi

    Science.gov (United States)

    Three sampling methods-sweep-net, hand-vacuum modified from a leaf vacuum/blower, and a wheeled, blower-vacuum designed to blow insects from the foliage into the vacuum port of a leaf vacuum-were compared as methods for sampling insects in sweetpotatoes, lpomead batatas L. Results of the 4-yr study...

  15. Method for sample preparation for cryoelectron microscopy (CEM) microreactor and loading platform

    OpenAIRE

    H.W. Zandbergen; Ahn, C. W.

    2008-01-01

    A method for sample preparation for cryoelectron microscopy (CEM), wherein the sample is held in a microreactor, wherein the conditions in the microreactor are regulated relative to the environment, wherein the sample in the microreactor is frozen according to a quench freeze process, whereupon the sample, in frozen condition, is placed in the electron microscope. A microreactor for use with cryoelectron microscopy (CEM), comprising a first and second membrane, which membranes, at least in a ...

  16. Quantitative method of determining beryllium or a compound thereof in a sample

    Science.gov (United States)

    McCleskey, T. Mark; Ehler, Deborah S.; John, Kevin D.; Burrell, Anthony K.; Collis, Gavin E.; Minogue, Edel M.; Warner, Benjamin P.

    2010-08-24

    A method of determining beryllium or a beryllium compound thereof in a sample, includes providing a sample suspected of comprising beryllium or a compound thereof, extracting beryllium or a compound thereof from the sample by dissolving in a solution, adding a fluorescent indicator to the solution to thereby bind any beryllium or a compound thereof to the fluorescent indicator, and determining the presence or amount of any beryllium or a compound thereof in the sample by measuring fluorescence.

  17. Estimation of the sugar cane cultivated area from LANDSAT images using the two phase sampling method

    Science.gov (United States)

    Parada, N. D. J. (Principal Investigator); Cappelletti, C. A.; Mendonca, F. J.; Lee, D. C. L.; Shimabukuro, Y. E.

    1982-01-01

    A two phase sampling method and the optimal sampling segment dimensions for the estimation of sugar cane cultivated area were developed. This technique employs visual interpretations of LANDSAT images and panchromatic aerial photographs considered as the ground truth. The estimates, as a mean value of 100 simulated samples, represent 99.3% of the true value with a CV of approximately 1%; the relative efficiency of the two phase design was 157% when compared with a one phase aerial photographs sample.

  18. Purging Musical Instrument Sample Databases Using Automatic Musical Instrument Recognition Methods

    OpenAIRE

    Livshin, Arie; Rodet, Xavier

    2009-01-01

    cote interne IRCAM: Livshin09a None / None National audience Compilation of musical instrument sample databases requires careful elimination of badly recorded samples and validation of sample classification into correct categories. This paper introduces algorithms for automatic removal of bad instrument samples using Automatic Musical Instrument Recognition and Outlier Detection techniques. Best evaluation results on a methodically contaminated sound database are achieved using the i...

  19. Sorbent-based sampling methods for volatile and semi-volatile organic compounds in air Part 1: Sorbent-based air monitoring options.

    Science.gov (United States)

    Woolfenden, Elizabeth

    2010-04-16

    Sorbent tubes/traps are widely used in combination with gas chromatographic (GC) analytical methods to monitor the vapour-phase fraction of organic compounds in air. Target compounds range in volatility from acetylene and freons to phthalates and PCBs and include apolar, polar and reactive species. Airborne vapour concentrations will vary depending on the nature of the location, nearby pollution sources, weather conditions, etc. Levels can range from low percent concentrations in stack and vent emissions to low part per trillion (ppt) levels in ultra-clean outdoor locations. Hundreds, even thousands of different compounds may be present in any given atmosphere. GC is commonly used in combination with mass spectrometry (MS) detection especially for environmental monitoring or for screening uncharacterised workplace atmospheres. Given the complexity and variability of organic vapours in air, no one sampling approach suits every monitoring scenario. A variety of different sampling strategies and sorbent media have been developed to address specific applications. Key sorbent-based examples include: active (pumped) sampling onto tubes packed with one or more sorbents held at ambient temperature; diffusive (passive) sampling onto sorbent tubes/cartridges; on-line sampling of air/gas streams into cooled sorbent traps; and transfer of air samples from containers (canisters, Tedlar) bags, etc.) into cooled sorbent focusing traps. Whichever sampling approach is selected, subsequent analysis almost always involves either solvent extraction or thermal desorption (TD) prior to GC(/MS) analysis. The overall performance of the air monitoring method will depend heavily on appropriate selection of key sampling and analytical parameters. This comprehensive review of air monitoring using sorbent tubes/traps is divided into 2 parts. (1) Sorbent-based air sampling option. (2) Sorbent selection and other aspects of optimizing sorbent-based air monitoring methods. The paper presents

  20. [Study on the optimization methods of common-batch identification of amphetamine samples].

    Science.gov (United States)

    Zhang, Jianxin; Zhang, Daming

    2008-07-01

    The essay introduced the technology of amphetamine identification and its optimization method. Impurity profiling of amphetamine was analyzed by GC-MS. Identification of common-batch amphetamine samples could be successfully finished by the data transition and pre-treating of the peak areas. The analytical method was improved by optimizing the techniques of sample extraction, gas chromatograph, sample separation and detection. PMID:18839544

  1. Flammability of litter sampled according to two different methods: comparison of results in laboratory experiments

    OpenAIRE

    Ganteaume, A.; Jappiot, M.; Curt, T.; Lampin, C.; Borgniet, L.

    2014-01-01

    In the laboratory, different types of litter samples (constructed v. intact) can be used in flammability experiments but the sampling method of these litters could affect litter flammability results. To assess this effect, samples of litters were collected in South-eastern France, according to two different methods previously used in other studies, one keeping intact the structure of the litter layers (non-constructed litter) and the other requiring the construction of the litter, using mainl...

  2. Two media method for linear attenuation coefficient determination of irregular soil samples

    International Nuclear Information System (INIS)

    In several situations of nuclear applications, the knowledge of gamma-ray linear attenuation coefficient for irregular samples is necessary, such as in soil physics and geology. This work presents the validation of a methodology for the determination of the linear attenuation coefficient (μ) of irregular shape samples, in such a way that it is not necessary to know the thickness of the considered sample. With this methodology irregular soil samples (undeformed field samples) from Londrina region, north of Parana were studied. It was employed the two media method for the μ determination. It consists of the μ determination through the measurement of a gamma-ray beam attenuation by the sample sequentially immersed in two different media, with known and appropriately chosen attenuation coefficients. For comparison, the theoretical value of μ was calculated by the product of the mass attenuation coefficient, obtained by the WinXcom code, and the measured value of the density sample. This software employs the chemical composition of the samples and supplies a table of the mass attenuation coefficients versus the photon energy. To verify the validity of the two media method, compared with the simple gamma ray transmission method, regular pome stone samples were used. With these results for the attenuation coefficients and their respective deviations, it was possible to compare the two methods. In this way we concluded that the two media method is a good tool for the determination of the linear attenuation coefficient of irregular materials, particularly in the study of soils samples. (author)

  3. [Preparation of sub-standard samples and XRF analytical method of powder non-metallic minerals].

    Science.gov (United States)

    Kong, Qin; Chen, Lei; Wang, Ling

    2012-05-01

    In order to solve the problem that standard samples of non-metallic minerals are not satisfactory in practical work by X-ray fluorescence spectrometer (XRF) analysis with pressed powder pellet, a method was studied how to make sub-standard samples according to standard samples of non-metallic minerals and to determine how they can adapt to analysis of mineral powder samples, taking the K-feldspar ore in Ebian-Wudu, Sichuan as an example. Based on the characteristic analysis of K-feldspar ore and the standard samples by X-ray diffraction (XRD) and chemical methods, combined with the principle of the same or similar between the sub-standard samples and unknown samples, the experiment developed the method of preparation of sub-standard samples: both of the two samples above mentioned should have the same kind of minerals and the similar chemical components, adapt mineral processing, and benefit making working curve. Under the optimum experimental conditions, a method for determination of SiO2, Al2O3, Fe2O3, TiO2, CaO, MgO, K2O and Na2O of K-feldspar ore by XRF was established. Thedetermination results are in good agreement with classical chemical methods, which indicates that this method was accurate. PMID:22827101

  4. Phase 2 sampling and analysis plan, Quality Assurance Project Plan, and environmental health and safety plan for the Clinch River Remedial Investigation: An addendum to the Clinch River RCRA Facility Investigation plan

    International Nuclear Information System (INIS)

    This document contains a three-part addendum to the Clinch River Resource Conservation and Recovery Act (RCRA) Facility Investigation Plan. The Clinch River RCRA Facility Investigation began in 1989, as part of the comprehensive remediation of facilities on the US Department of Energy Oak Ridge Reservation (ORR). The ORR was added to the National Priorities List in December 1989. The regulatory agencies have encouraged the adoption of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) terminology; therefore, the Clinch River activity is now referred to as the Clinch River Remedial Investigation (CRRI), not the Clinch River RCRA Facility Investigation. Part 1 of this document is the plan for sampling and analysis (S ampersand A) during Phase 2 of the CRRI. Part 2 is a revision of the Quality Assurance Project Plan for the CRRI, and Part 3 is a revision of the Environmental Health and Safety Plan for the CRRI. The Clinch River RI (CRRI) is designed to address the transport, fate, and distribution of waterborne contaminants (radionuclides, metals, and organic compounds) released from the DOE Oak Ridge Reservation (ORR) and to assess potential risks to human health and the environment associated with these contaminants. Primary areas of investigation are Melton Hill Reservoir, the Clinch River from Melton Hill Dam to its confluence with the Tennessee River, Poplar Creek, and Watts Bar Reservoir. The contaminants identified in the Clinch River/Watts Bar Reservoir (CR/WBR) downstream of the ORR are those associated with the water, suspended particles, deposited sediments, aquatic organisms, and wildlife feeding on aquatic organisms. The purpose of the Phase 2 S ampersand A Plan is to describe the proposed tasks and subtasks developed to meet the primary objectives of the CRRI

  5. Comparability among four invertebrate sampling methods, Fountain Creek Basin, Colorado, 2010-2012

    Science.gov (United States)

    Zuellig, Robert E.; Bruce, James F.; Stogner, Robert W.; Brown, Krystal D.

    2014-01-01

    The U.S. Geological Survey, in cooperation with Colorado Springs City Engineering and Colorado Springs Utilities, designed a study to determine if sampling method and sample timing resulted in comparable samples and assessments of biological condition. To accomplish this task, annual invertebrate samples were collected concurrently using four sampling methods at 15 U.S. Geological Survey streamflow gages in the Fountain Creek basin from 2010 to 2012. Collectively, the four methods are used by local (U.S. Geological Survey cooperative monitoring program) and State monitoring programs (Colorado Department of Public Health and Environment) in the Fountain Creek basin to produce two distinct sample types for each program that target single-and multiple-habitats. This study found distinguishable differences between single-and multi-habitat sample types using both community similarities and multi-metric index values, while methods from each program within sample type were comparable. This indicates that the Colorado Department of Public Health and Environment methods were compatible with the cooperative monitoring program methods within multi-and single-habitat sample types. Comparisons between September and October samples found distinguishable differences based on community similarities for both sample types, whereas only differences were found for single-habitat samples when multi-metric index values were considered. At one site, differences between September and October index values from single-habitat samples resulted in opposing assessments of biological condition. Direct application of the results to inform the revision of the existing Fountain Creek basin U.S. Geological Survey cooperative monitoring program are discussed.

  6. Use of Monte Carlo Bootstrap Method in the Analysis of Sample Sufficiency for Radioecological Data

    International Nuclear Information System (INIS)

    There are operational difficulties in obtaining samples for radioecological studies. Population data may no longer be available during the study and obtaining new samples may not be possible. These problems do the researcher sometimes work with a small number of data. Therefore, it is difficult to know whether the number of samples will be sufficient to estimate the desired parameter. Hence, it is critical do the analysis of sample sufficiency. It is not interesting uses the classical methods of statistic to analyze sample sufficiency in Radioecology, because naturally occurring radionuclides have a random distribution in soil, usually arise outliers and gaps with missing values. The present work was developed aiming to apply the Monte Carlo Bootstrap method in the analysis of sample sufficiency with quantitative estimation of a single variable such as specific activity of a natural radioisotope present in plants. The pseudo population was a small sample with 14 values of specific activity of 226Ra in forage palm (Opuntia spp.). Using the R software was performed a computational procedure to calculate the number of the sample values. The re sampling process with replacement took the 14 values of original sample and produced 10,000 bootstrap samples for each round. Then was calculated the estimated average θ for samples with 2, 5, 8, 11 and 14 values randomly selected. The results showed that if the researcher work with only 11 sample values, the average parameter will be within a confidence interval with 90% probability . (Author)

  7. An improved method for Organic Bound Tritium (OBT) determination in urine samples

    International Nuclear Information System (INIS)

    The Organic Bound Tritium (OBT) amount in the body may induce changes in the evaluation of the internal exposure to tritium, due to its different retention time relative to HTO. OBT measurements for urine are not performed routinely, mainly because of the lengthy work needed in preparation of the samples, when using the standard oxygen combustion method. A simpler and more rapid method based on liquid scintillation counting (LSC) was employed, and an evaluation was performed to check its suitability for urine samples. The principle of the proposed method is based on subtracting the LSC counts of the water phase sample (HTO) from the total activity of the urine sample (OBT + HTO). A good correlation was found between the results obtained when applying the proposed direct method and the Gold standard method. The minimum detectable activity when using this method was determined. (authors)

  8. Method and Implementation of High-speed Digital Sampling Technology Based on Impulse Radar Signal

    Directory of Open Access Journals (Sweden)

    Shen Shao-xiang

    2012-06-01

    Full Text Available A High-speed digital sampling technology suitable for periodical impulse radar signal is proposed in this paper. One bit high-speed quantize is constructed by differential comparator in FPGA. Time-interleaved digital sampling and buffer encoding are used to one bit stream based on the internal multi-phase clock of FPGA, to achieve sampling rate higher than 1 GHz. High speed digital sampling is realized by the accumulation of one bit sampling data with different comparison levels. An 8 bit, 1.6 GHz ADC based on the proposed method is realized on XC2V3000 Xilinx’s FPGA, which is successfully applied in GPR. The proposed method has the advantages of low cost and power consumption as compared with real sampling, and exhibits higher efficiency as compared with equivalent sampling.

  9. RESEARCH SAMPLING

    OpenAIRE

    NISHA MD

    2012-01-01

    No aspect of the research plan is more critical for assuring the usefulness of a study than the sampling strategy. It will determine if the results of the study can be applied as evidence and contributes to the trustworthiness of the results. The sampling strategy is a critical part of research design. An appropriate sampling plan is vital for drawing the right conclusions from a study. Good sampling is critical for the confident application of the study findings to other people, settings, or...

  10. Multiplex biotoxin surface plasmon resonance method for marine biotoxins in algal and seawater samples.

    Science.gov (United States)

    McNamee, Sara E; Elliott, Christopher T; Delahaut, Philippe; Campbell, Katrina

    2013-10-01

    A multiplex surface plasmon resonance (SPR) biosensor method for the detection of paralytic shellfish poisoning (PSP) toxins, okadaic acid (and analogues) and domoic acid was developed. This method was compared to enzyme-linked immunosorbent assay (ELISA) methods. Seawater samples (n=256) from around Europe were collected by the consortia of an EU project MIcroarrays for the Detection of Toxic Algae (MIDTAL) and evaluated using each method. A simple sample preparation procedure was developed which involved lysing and releasing the toxins from the algal cells with glass beads followed by centrifugation and filtering the extract before testing for marine biotoxins by both multi-SPR and ELISA. Method detection limits based on IC20 values for PSP, okadaic acid and domoic acid toxins were 0.82, 0.36 and 1.66 ng/ml, respectively, for the prototype multiplex SPR biosensor. Evaluation by SPR for seawater samples has shown that 47, 59 and 61 % of total seawater samples tested positive (result greater than the IC20) for PSP, okadaic acid (and analogues) and domoic acid toxins, respectively. Toxic samples were received mainly from Spain and Ireland. This work has demonstrated the potential of multiplex analysis for marine biotoxins in algal and seawater samples with results available for 24 samples within a 7 h period for three groups of key marine biotoxins. Multiplex immunological methods could therefore be used as early warning monitoring tools for a variety of marine biotoxins in seawater samples. PMID:23250726

  11. Quality Assurance for All

    Science.gov (United States)

    Cheung, Peter P. T.; Tsui, Cecilia B. S.

    2010-01-01

    For higher education reform, most decision-makers aspire to achieving a higher participation rate and a respectable degree of excellence with diversity at the same time. But very few know exactly how. External quality assurance is a fair basis for differentiation but there can be doubt and resistance in some quarters. Stakeholder interests differ…

  12. Mission Operations Assurance

    Science.gov (United States)

    Faris, Grant

    2012-01-01

    Integrate the mission operations assurance function into the flight team providing: (1) value added support in identifying, mitigating, and communicating the project's risks and, (2) being an essential member of the team during the test activities, training exercises and critical flight operations.

  13. Intercomparison study of sampling methods for the determination of polychlorinated biphenyl (PCB) in seawater

    International Nuclear Information System (INIS)

    The determination of organic pollutants in seawater is a serious problem, as their concentrations in the water column are typical in the fg - ng/L range. Available methods therefore includes extensive sampling and laboratory work. The development of simple sampling techniques for organochlorines (e.g. passive sampling with semipermeable membrane device (SPMD), mussel watch) is required. Three methods for the measurement of trace organochlorines in seawater were investigated: (1) the filtration (GF/F) and extraction (XAD-2 resin) of seawater with an in-situ pumping system, (2) biological-accumulation by mussels (mytilus edulis) and (3) passive sampling with SPMD

  14. RAPID FUSION METHOD FOR DETERMINATION OF PLUTONIUM ISOTOPES IN LARGE RICE SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.

    2013-03-01

    A new rapid fusion method for the determination of plutonium in large rice samples has been developed at the Savannah River National Laboratory (Aiken, SC, USA) that can be used to determine very low levels of plutonium isotopes in rice. The recent accident at Fukushima Nuclear Power Plant in March, 2011 reinforces the need to have rapid, reliable radiochemical analyses for radionuclides in environmental and food samples. Public concern regarding foods, particularly foods such as rice in Japan, highlights the need for analytical techniques that will allow very large sample aliquots of rice to be used for analysis so that very low levels of plutonium isotopes may be detected. The new method to determine plutonium isotopes in large rice samples utilizes a furnace ashing step, a rapid sodium hydroxide fusion method, a lanthanum fluoride matrix removal step, and a column separation process with TEVA Resin cartridges. The method can be applied to rice sample aliquots as large as 5 kg. Plutonium isotopes can be determined using alpha spectrometry or inductively-coupled plasma mass spectrometry (ICP-MS). The method showed high chemical recoveries and effective removal of interferences. The rapid fusion technique is a rugged sample digestion method that ensures that any refractory plutonium particles are effectively digested. The MDA for a 5 kg rice sample using alpha spectrometry is 7E-5 mBq g{sup -1}. The method can easily be adapted for use by ICP-MS to allow detection of plutonium isotopic ratios.

  15. Quality assurance in digital radiography

    International Nuclear Information System (INIS)

    At present, there is no standard way of evaluating performance characteristics of digital radiography systems. Continuous measurements of performance parameters are necessary in order to obtain images of high quality. Parameters of quality assurance in digital radiography, which can be evaluated with simple, quick methods, are spatial resolution, low-contrast detectability, dynamic range and exposure dose. Spatial resolution was determined by a lead bar pattern, whereas the other parameters were measured by commercially available phantoms. Performance measurements of 10 digital subtraction angiography (DSA) units and one digital radiography system for unsubtracted digital radiography were assessed. From these results, recommendations for performance parameter levels will be discussed. (author)

  16. Quality assurance in digital radiography

    International Nuclear Information System (INIS)

    At present, there is no standard way of evaluating performance characteristics of digital radiography systems. Continuous measurements of performance parameters are necessary in order to obtain images of high quality. Parameters of quality assurance in digital radiography, which can be evaluated with simple, quick methods, are spatial resolution, low-contrast detectability, dynamic range and exposure dose. Spatial resolution as determined by a lead bar pattern whereas other parameters were measured by commercially available phantoms. Performance measurements of 10 digital subtraction angiography (DSA) units and one digital radiography system for unsubtracted digital radiography were assessed. Recommendations for performance parameter levels are discussed. (author)

  17. Capability of analysis arsenic in geology sample by gamma-gamma coincidence method

    International Nuclear Information System (INIS)

    Gamma-gamma coincidence method has been successfully applied to the study of nuclear data and structure. Due to good abilities of background reduction, gamma-gamma coincidence method has been widely applied in neutron activation analysis. The experimental studies on geological and environmental samples have been conducted in several laboratories in the world. This report presents the results of Arsenic (As) analysis of geological sample by neutron activation analysis with coincidence method. The results show that the linearity between concentration in sample and count rate of peak in coincidence measurements and the influence of isotopes was eliminated and the background was reduced by application of this method in comparison with the conventional method that uses a detector. The results also found out that detection limits for analysis of As in geological samples were improved. (author)

  18. [Research of Outlier Samples Elimination Methods for Near-Infrared Spectral Analysis of Blood Glucose].

    Science.gov (United States)

    Lin, Yongzhong; Li, Lina; Lin, Tianliang

    2015-12-01

    For the near-infrared (NIR) spectral analysis of the concentration of blood glucose, the calibration accuracy can be affected because of the existing of outlier samples. In this research, a Monte-Carlo cross validation (MCCV) method is constructed for eliminating outlier samples. The human blood plasma experiment in vitro and the human body experiment in vivo were introduced to evaluate the MCCV method for its application effect in NIR spectral analysis of blood glucose. And the uninformative sample elimination method based on modified uninformative variable elimination (MUVE-USE) was employed in this study for the comparison with MCCV. The results indicated that, like the MUVE-USE method, the outlier samples elimination method based on MCCV could be used to eliminate the outlier samples which came from gross errors (such as bad sample) or system errors (such as baseline drift). In addition, the outlier samples from the random errors of uncertain causes which affect model accuracy can be eliminated simultaneously by MCCV. The elimination of multiple outlier samples is beneficial to the improvement of prediction accuracy of calibration model. PMID:27079108

  19. Analysis method on shoot precision of weapon in small-sample case

    Institute of Scientific and Technical Information of China (English)

    Jiang Jun; Song Baowei; Liang Qingwei

    2007-01-01

    Because of limits of cost, in general, the test data of weapons are shortness. It is always an important topic that to gain scientific results of weapon performance analyses in small-sample case. Based on the analysis of distribution function characteristics and grey mathematics, a weighting grey method in small-sample case is presented. According to the analysis of test data of a weapon, it is proved that the method is a good method to deal with data in the small-sample case and has a high value in the analysis of weapon performance.

  20. Determination of thorium and uranium contents in soil samples using SSNTD's passive method

    Indian Academy of Sciences (India)

    T A Salama; U Seddik; T M Dsoky; A Ahmed Morsy; R El-Asser

    2006-08-01

    Thorium-to-uranium ratios have been determined in different soil samples using CR-39 and LR-115-II solid-state nuclear track detectors (SSNTDs). A calibration method based on determination of SSNTD registration sensitivity ratio for -particles of thorium and uranium series has been developed. Thorium and uranium contents of the standard soil samples have been determined and compared with its known values. There is a good agreement between the results of this method and the values of standard samples. The method is simple, inexpensive, non-destructive and has a wide range of applications in environment, building materials and petroleum fields.

  1. Standard-free method for body fluid samples such as saliva, sweat, snivel and tear

    International Nuclear Information System (INIS)

    We have developed standard-free methods for PIXE analysis of hair, nail, urine and serum, and they have widely been applied to studies on human exposure to some toxic elements caused by pollution in many countries. Although these samples are known to be quite suited for evaluating human exposure to toxic elements, there is a cause where it is required to quantitatively analyze other samples taken from people. We have examined sweat, saliva, snivel and tear, which are expected to be useful for estimating concentration of various elements in a human body. However, sufficient quantities of them are difficult to be taken from a human body and it is required to establish standard-free methods for these samples. In the present work, standard-free methods for sweat and saliva were established and its accuracy and reproducibility are confirmed. It becomes possible to quantitatively analyze only a drop of sweat and saliva by means of this method. For snivel and tear, potassium concentration is obtained by the internal-standard method for a small-spot sample and the conversion coefficient required for the standard-free method was evaluated. It is found that analyses of these samples give us useful information about some specific elements. As the standard-free methods are free from dryness of samples, which becomes a serious problem in the case where the internal-standard method is applied, it is expected to give more essential information about elemental concentration in a human body. (author)

  2. A Generalized Method for Integrating Rule-based Knowledge into Inductive Methods Through Virtual Sample Creation

    CERN Document Server

    Iqbal, Ridwan Al

    2011-01-01

    Hybrid learning methods use theoretical knowledge of a domain and a set of classified examples to develop a method for classification. Methods that use domain knowledge have been shown to perform better than inductive learners. However, there is no general method to include domain knowledge into all inductive learning algorithms as all hybrid methods are highly specialized for a particular algorithm. We present an algorithm that will take domain knowledge in the form of propositional rules, generate artificial examples from the rules and also remove instances likely to be flawed. This enriched dataset then can be used by any learning algorithm. Experimental results of different scenarios are shown that demonstrate this method to be more effective than simple inductive learning.

  3. Methods, compounds and systems for detecting a microorganism in a sample

    Energy Technology Data Exchange (ETDEWEB)

    Colston, Jr, Bill W.; Fitch, J. Patrick; Gardner, Shea N.; Williams, Peter L.; Wagner, Mark C.

    2016-09-06

    Methods to identify a set of probe polynucleotides suitable for detecting a set of targets and in particular methods for identification of primers suitable for detection of target microorganisms related polynucleotides, set of polynucleotides and compositions, and related methods and systems for detection and/or identification of microorganisms in a sample.

  4. INVESTIGATION OF THE TOTAL ORGANIC HALOGEN ANALYTICAL METHOD AT THE WASTE SAMPLING CHARACTERIZATION FACILITY (WSCF)

    International Nuclear Information System (INIS)

    Total organic halogen (TOX) is used as a parameter to screen groundwater samples at the Hanford Site. Trending is done for each groundwater well, and changes in TOX and other screening parameters can lead to costly changes in the monitoring protocol. The Waste Sampling and Characterization Facility (WSCF) analyzes groundwater samples for TOX using the United States Environmental Protection Agency (EPA) SW-846 method 9020B (EPA 1996a). Samples from the Soil and Groundwater Remediation Project (S and GRP) are submitted to the WSCF for analysis without information regarding the source of the sample; each sample is in essence a 'blind' sample to the laboratory. Feedback from the S and GRP indicated that some of the WSCF-generated TOX data from groundwater wells had a number of outlier values based on the historical trends (Anastos 2008a). Additionally, analysts at WSCF observed inconsistent TOX results among field sample replicates. Therefore, the WSCF lab performed an investigation of the TOX analysis to determine the cause of the outlier data points. Two causes were found that contributed to generating out-of-trend TOX data: (1) The presence of inorganic chloride in the groundwater samples: at inorganic chloride concentrations greater than about 10 parts per million (ppm), apparent TOX values increase with increasing chloride concentration. A parallel observation is the increase in apparent breakthrough of TOX from the first to the second activated-carbon adsorption tubes with increasing inorganic chloride concentration. (2) During the sample preparation step, excessive purging of the adsorption tubes with oxygen pressurization gas after sample loading may cause channeling in the activated-carbon bed. This channeling leads to poor removal of inorganic chloride during the subsequent wash step with aqueous potassium nitrate. The presence of this residual inorganic chloride then produces erroneously high TOX values. Changes in sample preparation were studied to more

  5. INVESTIGATION OF THE TOTAL ORGANIC HALOGEN ANALYTICAL METHOD AT THE WASTE SAMPLING CHARACTERIZATION FACILITY (WSCF)

    Energy Technology Data Exchange (ETDEWEB)

    DOUGLAS JG; MEZNARICH HD, PHD; OLSEN JR; ROSS GA; STAUFFER M

    2008-09-30

    Total organic halogen (TOX) is used as a parameter to screen groundwater samples at the Hanford Site. Trending is done for each groundwater well, and changes in TOX and other screening parameters can lead to costly changes in the monitoring protocol. The Waste Sampling and Characterization Facility (WSCF) analyzes groundwater samples for TOX using the United States Environmental Protection Agency (EPA) SW-846 method 9020B (EPA 1996a). Samples from the Soil and Groundwater Remediation Project (S&GRP) are submitted to the WSCF for analysis without information regarding the source of the sample; each sample is in essence a 'blind' sample to the laboratory. Feedback from the S&GRP indicated that some of the WSCF-generated TOX data from groundwater wells had a number of outlier values based on the historical trends (Anastos 2008a). Additionally, analysts at WSCF observed inconsistent TOX results among field sample replicates. Therefore, the WSCF lab performed an investigation of the TOX analysis to determine the cause of the outlier data points. Two causes were found that contributed to generating out-of-trend TOX data: (1) The presence of inorganic chloride in the groundwater samples: at inorganic chloride concentrations greater than about 10 parts per million (ppm), apparent TOX values increase with increasing chloride concentration. A parallel observation is the increase in apparent breakthrough of TOX from the first to the second activated-carbon adsorption tubes with increasing inorganic chloride concentration. (2) During the sample preparation step, excessive purging of the adsorption tubes with oxygen pressurization gas after sample loading may cause channeling in the activated-carbon bed. This channeling leads to poor removal of inorganic chloride during the subsequent wash step with aqueous potassium nitrate. The presence of this residual inorganic chloride then produces erroneously high TOX values. Changes in sample preparation were studied to more

  6. Basic Study of Establishment of Quality Assurance Processes to Develop an Integrated Quality Assurance System for Nuclear Power Plant Construction

    International Nuclear Information System (INIS)

    An integrated quality assurance system has necessitated carrying out quality assurance programs in a systematic manner because the opportunities to expand business in overseas markets have increased since the export of a nuclear power plant to UAE in 2009. In this study, we use PDCA method to systematically analyze the quality assurance procedures that were used in previous projects for constructing nuclear power plants. We reached a classification system of quality assurance processes at each phase of nuclear power plant construction by integrating similar work related to quality such as planning, design, equipment manufacturing, construction and start-up. We also established a hierarchy of quality assurance processes to develop an integrated quality assurance system as a technology goal to be developed later. To obtain most updated quality assurance activities, a quality assurance process is structured by integrating similar works analyzed from quality assurance procedures through PDCA cycle method. At the implementation phase of Hierarchy of quality processes and sequence of processes for constructing nuclear power plant are established in this study. Integrated quality assurance system is to be developed by connecting organizations as well as stakeholders such as owners, Architect engineering, suppliers, contractors, and sub-contractors to carry out assigned work efficiently

  7. Monte Carlo Methods Development and Applications in Conformational Sampling of Proteins

    DEFF Research Database (Denmark)

    Tian, Pengfei

    sampling methods to address these two problems. First of all, a novel technique has been developed for reliably estimating diffusion coefficients for use in the enhanced sampling of molecular simulations. A broad applicability of this method is illustrated by studying various simulation problems such as...... sufficient to provide an accurate structural and dynamical description of certain properties of proteins, (2), it is difficult to obtain correct statistical weights of the samples generated, due to lack of equilibrium sampling. In this dissertation I present several new methodologies based on Monte Carlo...... protein folding and aggregation. Second, by combining Monte Carlo sampling with a flexible probabilistic model of NMR chemical shifts, a series of simulation strategies are developed to accelerate the equilibrium sampling of free energy landscapes of proteins. Finally, a novel approach is presented to...

  8. Method optimization and quality assurance in speciation analysis using high performance liquid chromatography with detection by inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt

    1998-01-01

    operating characteristics of the entire hyphenated system. An isocratic HPLC system, which employs an aqueous mobile phase with organic buffer constituents, is well suited for introduction into the ICP-MS because of the stability of the detector response and high degree of analyte sensitivity attained...... speciation in the shrimp sample. With this analytical technique the HPLC retention time in combination with mass analysis of the molecular ions and their collision-induced fragments provide almost conclusive evidence of the identity of the analyte species. The speciation methods are validated by establishing...

  9. Sampling Methods for Detection and Monitoring of the Asian Citrus Psyllid (Hemiptera: Psyllidae).

    Science.gov (United States)

    Monzo, C; Arevalo, H A; Jones, M M; Vanaclocha, P; Croxton, S D; Qureshi, J A; Stansly, P A

    2015-06-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama is a key pest of citrus due to its role as vector of citrus greening disease or "huanglongbing." ACP monitoring is considered an indispensable tool for management of vector and disease. In the present study, datasets collected between 2009 and 2013 from 245 citrus blocks were used to evaluate precision, sensitivity for detection, and efficiency of five sampling methods. The number of samples needed to reach a 0.25 standard error-mean ratio was estimated using Taylor's power law and used to compare precision among sampling methods. Comparison of detection sensitivity and time expenditure (cost) between stem-tap and other sampling methodologies conducted consecutively at the same location were also assessed. Stem-tap sampling was the most efficient sampling method when ACP densities were moderate to high and served as the basis for comparison with all other methods. Protocols that grouped trees near randomly selected locations across the block were more efficient than sampling trees at random across the block. Sweep net sampling was similar to stem-taps in number of captures per sampled unit, but less precise at any ACP density. Yellow sticky traps were 14 times more sensitive than stem-taps but much more time consuming and thus less efficient except at very low population densities. Visual sampling was efficient for detecting and monitoring ACP at low densities. Suction sampling was time consuming and taxing but the most sensitive of all methods for detection of sparse populations. This information can be used to optimize ACP monitoring efforts. PMID:26313984

  10. A method for positive forensic identification of samples from extremely low-coverage sequence data

    OpenAIRE

    Vohr, SH; Buen Abad Najar, CF; Shapiro, B.; Green, RE

    2015-01-01

    Background Determining whether two DNA samples originate from the same individual is difficult when the amount of retrievable DNA is limited. This is often the case for ancient, historic, and forensic samples. The most widely used approaches rely on amplification of a defined panel of multi-allelic markers and comparison to similar data from other samples. When the amount retrievable DNA is low these approaches fail. Results We describe a new method for assessing whether shotgun DNA sequence ...

  11. Optimising Bacterial DNA Extraction from Faecal Samples: Comparison of Three Methods

    OpenAIRE

    Smith, Birgitte; Li, Nan; Andersen, Anders Schou; Slotved, Hans Christian; Krogfelt, Karen Angeliki

    2011-01-01

    Culture independent methods are used widely in diagnostic laboratories for infectious disease Isolation of genomic DNA from clinical samples is the first and important step in the procedure. Several procedures for extracting DNA from faecal samples have been described, including different mechanical cell disruptors. To our knowledge, the use of TissueLyser as a mechanical disruptor on faecal samples before DNA extraction has not been previously described. The purpose of the study was to imple...

  12. Minimally invasive blood sampling method for genetic studies on Gopherus tortoises

    OpenAIRE

    García–Feria, L. M.; Ureña–Aranda, C. A.; Espinosa de los Monteros, A.

    2015-01-01

    Obtaining good quality tissue samples is the first hurdle in any molecular study. This is especially true for studies involving management and conservation of wild fauna. In the case of tortoises, the most common sources of DNA are blood samples. However, only a minimal amount of blood is required for PCR assays. Samples are obtained mainly from the brachial and jugular vein after restraining the animal chemically, or from conscious individuals by severe handling methods and clamping. Herein,...

  13. ESTIMATION AND SELECTION OF PLASMA IODENT CORN SAMPLES ON DROUGHT-RESISTANCE BY PHYSIOLOGICAL METHODS

    OpenAIRE

    Grabovskaya, T.

    2009-01-01

    The complex estimation of corn samples on drought-resistance was conducted by physiological methods. It was proven that samples which grown on osmotic solutions of sucrose with the gradual increase of pressure have greater water-retaining ability and greater content of bound-water. Also in the selected samples the less percent of hydrolyzed starch in the cells of root caps was indicated.

  14. Randomized Methods for Design of Uncertain Systems: Sample Complexity and Sequential Algorithms

    OpenAIRE

    Alamo, T.; Tempo, R.; A. Luque; Ramirez, D. R.

    2013-01-01

    In this paper, we study randomized methods for feedback design of uncertain systems. The first contribution is to derive the sample complexity of various constrained control problems. In particular, we show the key role played by the binomial distribution and related tail inequalities, and compute the sample complexity. This contribution significantly improves the existing results by reducing the number of required samples in the randomized algorithm. These results are then applied to the ana...

  15. Precision and Accuracy of k0-NAA Method for Analysis of Multi Elements in Reference Samples

    International Nuclear Information System (INIS)

    Accuracy and precision of k0-NAA method could determine in the analysis of multi elements contained in reference samples. The analyzed results of multi elements in SRM 1633b sample were obtained with optimum results in bias of 20% but it is in a good accuracy and precision. The analyzed results of As, Cd and Zn in CCQM-P29 rice flour sample were obtained with very good result in bias of 0.5 - 5.6%. (author)

  16. Comparison of LSO samples produced by Czochralsky and modified Musatov methods

    CERN Document Server

    Antich, P; Tsyganov, E N; Garmash, V; Zheleznykh, I

    2000-01-01

    This study is based on test results of 30 LSO samples produced by the POLUS Research Institute in Moscow, Russia, for the University of Texas Southwestern Medical Center at Dallas. Samples were produced by the Czochralsky and the modified Musatov methods. Pulse-height spectra from sup 2 sup 2 Na positron annihilations were analyzed and conclusions are drawn. After some minor corrections to the modified Musatov technology, samples could be recommended for use in PET systems.

  17. Probabilistic Requirements (Partial) Verification Methods Best Practices Improvement. Variables Acceptance Sampling Calculators: Empirical Testing. Volume 2

    Science.gov (United States)

    Johnson, Kenneth L.; White, K. Preston, Jr.

    2012-01-01

    The NASA Engineering and Safety Center was requested to improve on the Best Practices document produced for the NESC assessment, Verification of Probabilistic Requirements for the Constellation Program, by giving a recommended procedure for using acceptance sampling by variables techniques as an alternative to the potentially resource-intensive acceptance sampling by attributes method given in the document. In this paper, the results of empirical tests intended to assess the accuracy of acceptance sampling plan calculators implemented for six variable distributions are presented.

  18. Impact of Frequentist and Bayesian Methods on Survey Sampling Practice: A Selective Appraisal

    OpenAIRE

    Rao, J. N. K.

    2011-01-01

    According to Hansen, Madow and Tepping [J. Amer. Statist. Assoc. 78 (1983) 776--793], "Probability sampling designs and randomization inference are widely accepted as the standard approach in sample surveys." In this article, reasons are advanced for the wide use of this design-based approach, particularly by federal agencies and other survey organizations conducting complex large scale surveys on topics related to public policy. Impact of Bayesian methods in survey sampling is also discussed...

  19. Fast and Flexible Geometric Method For Enhancing MC Sampling of Compact Configurations For Protein Docking Problem

    OpenAIRE

    Ozkan, Aysegul; Flores-Canales, Jose C.; Sitharam, Meera; Kurnikova, Maria

    2014-01-01

    EASAL (efficient atlasing and sampling of assembly landscapes) is a recently reported geometric method for representing, visualizing, sampling and computing integrals over the potential energy landscape tailored for small molecular assemblies. EASAL's efficiency arises from the fact that small assembly landscapes permit the use of so-called Cayley parameters (inter-atomic distances) for geometric representation and sampling of the assembly configuration space regions; this results in their is...

  20. Optimisation of the T-square sampling method to estimate population sizes

    OpenAIRE

    Chalabi Zaid; Bostoen Kristof; Grais Rebecca F

    2007-01-01

    Abstract Population size and density estimates are needed to plan resource requirements and plan health related interventions. Sampling frames are not always available necessitating surveys using non-standard household sampling methods. These surveys are time-consuming, difficult to validate, and their implementation could be optimised. Here, we discuss an example of an optimisation procedure for rapid population estimation using T-Square sampling which has been used recently to estimate popu...