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Sample records for protocols sampling techniques

  1. Affinity biosensors: techniques and protocols

    National Research Council Canada - National Science Library

    Rogers, Kim R; Mulchandani, Ashok

    1998-01-01

    ..., and government to begin or expand their biosensors research. This volume, Methods in Biotechnology vol. 7: Affinity Biosensors: Techniques and Protocols, describes a variety of classical and emerging transduction technologies that have been interfaced to bioaffinity elements (e.g., antibodies and receptors). Some of the reas...

  2. Samples and Sampling Protocols for Scientific Investigations | Joel ...

    African Journals Online (AJOL)

    ... from sampling, through sample preparation, calibration to final measurement and reporting. This paper, therefore offers useful information on practical guidance on sampling protocols in line with best practice and international standards. Keywords: Sampling, sampling protocols, chain of custody, analysis, documentation ...

  3. Urine sample collection protocols for bioassay samples

    Energy Technology Data Exchange (ETDEWEB)

    MacLellan, J.A.; McFadden, K.M.

    1992-11-01

    In vitro radiobioassay analyses are used to measure the amount of radioactive material excreted by personnel exposed to the potential intake of radioactive material. The analytical results are then used with various metabolic models to estimate the amount of radioactive material in the subject`s body and the original intake of radioactive material. Proper application of these metabolic models requires knowledge of the excretion period. It is normal practice to design the bioassay program based on a 24-hour excretion sample. The Hanford bioassay program simulates a total 24-hour urine excretion sample with urine collection periods lasting from one-half hour before retiring to one-half hour after rising on two consecutive days. Urine passed during the specified periods is collected in three 1-L bottles. Because the daily excretion volume given in Publication 23 of the International Commission on Radiological Protection (ICRP 1975, p. 354) for Reference Man is 1.4 L, it was proposed to use only two 1-L bottles as a cost-saving measure. This raised the broader question of what should be the design capacity of a 24-hour urine sample kit.

  4. Urine sample collection protocols for bioassay samples

    Energy Technology Data Exchange (ETDEWEB)

    MacLellan, J.A.; McFadden, K.M.

    1992-11-01

    In vitro radiobioassay analyses are used to measure the amount of radioactive material excreted by personnel exposed to the potential intake of radioactive material. The analytical results are then used with various metabolic models to estimate the amount of radioactive material in the subject's body and the original intake of radioactive material. Proper application of these metabolic models requires knowledge of the excretion period. It is normal practice to design the bioassay program based on a 24-hour excretion sample. The Hanford bioassay program simulates a total 24-hour urine excretion sample with urine collection periods lasting from one-half hour before retiring to one-half hour after rising on two consecutive days. Urine passed during the specified periods is collected in three 1-L bottles. Because the daily excretion volume given in Publication 23 of the International Commission on Radiological Protection (ICRP 1975, p. 354) for Reference Man is 1.4 L, it was proposed to use only two 1-L bottles as a cost-saving measure. This raised the broader question of what should be the design capacity of a 24-hour urine sample kit.

  5. Fetal MRI: techniques and protocols

    International Nuclear Information System (INIS)

    Prayer, Daniela; Brugger, Peter Christian; Prayer, Lucas

    2004-01-01

    The development of ultrafast sequences has led to a significant improvement in fetal MRI. Imaging protocols have to be adjusted to the rapidly developing fetal central nervous system (CNS) and to the clinical question. Sequence parameters must be changed to cope with the respective developmental stage, to produce images free from motion artefacts and to provide optimum visualization of the region and focus of interest. In contrast to postnatal studies, every suspect fetal CNS abnormality requires examination of the whole fetus and the extrafetal intrauterine structures including the uterus. This approach covers both aspects of fetal CNS disorders: isolated and complex malformations and cerebral lesions arising from the impaired integrity of the feto-placental unit. (orig.)

  6. Fetal MRI: techniques and protocols

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, Daniela [Department of Neuroradiology, University Clinics of Radiodiagnostics, Medical University Vienna, Waehringerguertel 18-10, 1090, Vienna (Austria); Brugger, Peter Christian [Department of Anatomy, Integrative Morphology Group, Medical University Vienna (Austria); Prayer, Lucas [Diagnosezentrum Urania, Vienna (Austria)

    2004-09-01

    The development of ultrafast sequences has led to a significant improvement in fetal MRI. Imaging protocols have to be adjusted to the rapidly developing fetal central nervous system (CNS) and to the clinical question. Sequence parameters must be changed to cope with the respective developmental stage, to produce images free from motion artefacts and to provide optimum visualization of the region and focus of interest. In contrast to postnatal studies, every suspect fetal CNS abnormality requires examination of the whole fetus and the extrafetal intrauterine structures including the uterus. This approach covers both aspects of fetal CNS disorders: isolated and complex malformations and cerebral lesions arising from the impaired integrity of the feto-placental unit. (orig.)

  7. Development of bull trout sampling protocols

    Science.gov (United States)

    R. F. Thurow; J. T. Peterson; J. W. Guzevich

    2001-01-01

    This report describes results of research conducted in Washington in 2000 through Interagency Agreement #134100H002 between the U.S. Fish and Wildlife Service (USFWS) and the U.S. Forest Service Rocky Mountain Research Station (RMRS). The purpose of this agreement is to develop a bull trout (Salvelinus confluentus) sampling protocol by integrating...

  8. Automata Techniques for Epistemic Protocol Synthesis

    Directory of Open Access Journals (Sweden)

    Guillaume Aucher

    2014-04-01

    Full Text Available In this work we aim at applying automata techniques to problems studied in Dynamic Epistemic Logic, such as epistemic planning. To do so, we first remark that repeatedly executing ad infinitum a propositional event model from an initial epistemic model yields a relational structure that can be finitely represented with automata. This correspondence, together with recent results on uniform strategies, allows us to give an alternative decidability proof of the epistemic planning problem for propositional events, with as by-products accurate upper-bounds on its time complexity, and the possibility to synthesize a finite word automaton that describes the set of all solution plans. In fact, using automata techniques enables us to solve a much more general problem, that we introduce and call epistemic protocol synthesis.

  9. Sample preparation techniques for (p, X) spectrometry

    International Nuclear Information System (INIS)

    Whitehead, N.E.

    1985-01-01

    Samples are ashed at low temperature, using oxygen plasma; a rotary evaporator, and freeze drying speeded up the ashing. The new design of apparatus manufactured was only 10 watt but was as efficient as a 200 watt commercial machine; a circuit diagram is included. Samples of hair and biopsy samples of skin were analysed by the technique. A wool standard was prepared for interlaboratory comparison exercises. It was based on New Zealand merino sheep wool and was 2.9 kg in weight. A washing protocol was developed, which preserves most of the trace element content. The wool was ground in liquid nitrogen using a plastic pestle and beaker, driven by a rotary drill press. (author)

  10. The Network Protocol Analysis Technique in Snort

    Science.gov (United States)

    Wu, Qing-Xiu

    Network protocol analysis is a network sniffer to capture data for further analysis and understanding of the technical means necessary packets. Network sniffing is intercepted by packet assembly binary format of the original message content. In order to obtain the information contained. Required based on TCP / IP protocol stack protocol specification. Again to restore the data packets at protocol format and content in each protocol layer. Actual data transferred, as well as the application tier.

  11. Advanced Curation Protocols for Mars Returned Sample Handling

    Science.gov (United States)

    Bell, M.; Mickelson, E.; Lindstrom, D.; Allton, J.

    Introduction: Johnson Space Center has over 30 years experience handling precious samples which include Lunar rocks and Antarctic meteorites. However, we recognize that future curation of samples from such missions as Genesis, Stardust, and Mars S mple Return, will require a high degree of biosafety combined witha extremely low levels of inorganic, organic, and biological contamination. To satisfy these requirements, research in the JSC Advanced Curation Lab is currently focused toward two major areas: preliminary examination techniques and cleaning and verification techniques . Preliminary Examination Techniques : In order to minimize the number of paths for contamination we are exploring the synergy between human &robotic sample handling in a controlled environment to help determine the limits of clean curation. Within the Advanced Curation Laboratory is a prototype, next-generation glovebox, which contains a robotic micromanipulator. The remotely operated manipulator has six degrees-of- freedom and can be programmed to perform repetitive sample handling tasks. Protocols are being tested and developed to perform curation tasks such as rock splitting, weighing, imaging, and storing. Techniques for sample transfer enabling more detailed remote examination without compromising the integrity of sample science are also being developed . The glovebox is equipped with a rapid transfer port through which samples can be passed without exposure. The transfer is accomplished by using a unique seal and engagement system which allows passage between containers while maintaining a first seal to the outside environment and a second seal to prevent the outside of the container cover and port door from becoming contaminated by the material being transferred. Cleaning and Verification Techniques: As part of the contamination control effort, innovative cleaning techniques are being identified and evaluated in conjunction with sensitive cleanliness verification methods. Towards this

  12. Development of SYVAC sampling techniques

    International Nuclear Information System (INIS)

    Prust, J.O.; Dalrymple, G.J.

    1985-04-01

    This report describes the requirements of a sampling scheme for use with the SYVAC radiological assessment model. The constraints on the number of samples that may be taken is considered. The conclusions from earlier studies using the deterministic generator sampling scheme are summarised. The method of Importance Sampling and a High Dose algorithm, which are designed to preferentially sample in the high dose region of the parameter space, are reviewed in the light of experience gained from earlier studies and the requirements of a site assessment and sensitivity analyses. In addition the use of an alternative numerical integration method for estimating risk is discussed. It is recommended that the method of Importance Sampling is developed and tested for use with SYVAC. An alternative numerical integration method is not recommended for investigation at this stage but should be the subject of future work. (author)

  13. Two sampling techniques for game meat

    OpenAIRE

    van der Merwe, Maretha; Jooste, Piet J.; Hoffman, Louw C.; Calitz, Frikkie J.

    2013-01-01

    A study was conducted to compare the excision sampling technique used by the export market and the sampling technique preferred by European countries, namely the biotrace cattle and swine test. The measuring unit for the excision sampling was grams (g) and square centimetres (cm2) for the swabbing technique. The two techniques were compared after a pilot test was conducted on spiked approved beef carcasses (n = 12) that statistically proved the two measuring units correlated. The two sampling...

  14. Evaluation protocol for amusia: Portuguese sample.

    Science.gov (United States)

    Peixoto, Maria Conceição; Martins, Jorge; Teixeira, Pedro; Alves, Marisa; Bastos, José; Ribeiro, Carlos

    2012-12-01

    Amusia is a disorder that affects the processing of music. Part of this processing happens in the primary auditory cortex. The study of this condition allows us to evaluate the central auditory pathways. To explore the diagnostic evaluation tests of amusia. The authors propose an evaluation protocol for patients with suspected amusia (after brain injury or complaints of poor musical perception), in parallel with the assessment of central auditory processing, already implemented in the department. The Montreal Evaluation of Battery of amusia was the basis for the selection of the tests. From this comprehensive battery of tests we selected some of the musical examples to evaluate different musical aspects, including memory and perception of music, ability concerning musical recognition and discrimination. In terms of memory there is a test for assessing delayed memory, adapted to the Portuguese culture. Prospective study. Although still experimental, with the possibility of adjustments in the assessment, we believe that this assessment, combined with the study of central auditory processing, will allow us to understand some central lesions, congenital or acquired hearing perception limitations.

  15. Newly introduced sample preparation techniques: towards miniaturization.

    Science.gov (United States)

    Costa, Rosaria

    2014-01-01

    Sampling and sample preparation are of crucial importance in an analytical procedure, representing quite often a source of errors. The technique chosen for the isolation of analytes greatly affects the success of a chemical determination. On the other hand, growing concerns about environmental and human safety, along with the introduction of international regulations for quality control, have moved the interest of scientists towards specific needs. Newly introduced sample preparation techniques are challenged to meet new criteria: (i) miniaturization, (ii) higher sensitivity and selectivity, and (iii) automation. In this survey, the most recent techniques introduced in the field of sample preparation will be described and discussed, along with many examples of applications.

  16. Two sampling techniques for game meat

    Directory of Open Access Journals (Sweden)

    Maretha van der Merwe

    2013-03-01

    Full Text Available A study was conducted to compare the excision sampling technique used by the export market and the sampling technique preferred by European countries, namely the biotrace cattle and swine test. The measuring unit for the excision sampling was grams (g and square centimetres (cm2 for the swabbing technique. The two techniques were compared after a pilot test was conducted on spiked approved beef carcasses (n = 12 that statistically proved the two measuring units correlated. The two sampling techniques were conducted on the same game carcasses (n = 13 and analyses performed for aerobic plate count (APC, Escherichia coli and Staphylococcus aureus, for both techniques. A more representative result was obtained by swabbing and no damage was caused to the carcass. Conversely, the excision technique yielded fewer organisms and caused minor damage to the carcass. The recovery ratio from the sampling technique improved 5.4 times for APC, 108.0 times for E. coli and 3.4 times for S. aureus over the results obtained from the excision technique. It was concluded that the sampling methods of excision and swabbing can be used to obtain bacterial profiles from both export and local carcasses and could be used to indicate whether game carcasses intended for the local market are possibly on par with game carcasses intended for the export market and therefore safe for human consumption.

  17. Two sampling techniques for game meat.

    Science.gov (United States)

    van der Merwe, Maretha; Jooste, Piet J; Hoffman, Louw C; Calitz, Frikkie J

    2013-03-20

    A study was conducted to compare the excision sampling technique used by the export market and the sampling technique preferred by European countries, namely the biotrace cattle and swine test. The measuring unit for the excision sampling was grams (g) and square centimetres (cm2) for the swabbing technique. The two techniques were compared after a pilot test was conducted on spiked approved beef carcasses (n = 12) that statistically proved the two measuring units correlated. The two sampling techniques were conducted on the same game carcasses (n = 13) and analyses performed for aerobic plate count (APC), Escherichia coli and Staphylococcus aureus, for both techniques. A more representative result was obtained by swabbing and no damage was caused to the carcass. Conversely, the excision technique yielded fewer organisms and caused minor damage to the carcass. The recovery ratio from the sampling technique improved 5.4 times for APC, 108.0 times for E. coli and 3.4 times for S. aureus over the results obtained from the excision technique. It was concluded that the sampling methods of excision and swabbing can be used to obtain bacterial profiles from both export and local carcasses and could be used to indicate whether game carcasses intended for the local market are possibly on par with game carcasses intended for the export market and therefore safe for human consumption.

  18. Critical evaluation of sample pretreatment techniques.

    Science.gov (United States)

    Hyötyläinen, Tuulia

    2009-06-01

    Sample preparation before chromatographic separation is the most time-consuming and error-prone part of the analytical procedure. Therefore, selecting and optimizing an appropriate sample preparation scheme is a key factor in the final success of the analysis, and the judicious choice of an appropriate procedure greatly influences the reliability and accuracy of a given analysis. The main objective of this review is to critically evaluate the applicability, disadvantages, and advantages of various sample preparation techniques. Particular emphasis is placed on extraction techniques suitable for both liquid and solid samples.

  19. Energy Reduction Multipath Routing Protocol for MANET Using Recoil Technique

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Sahu

    2018-04-01

    Full Text Available In Mobile Ad-hoc networks (MANET, power conservation and utilization is an acute problem and has received significant attention from academics and industry in recent years. Nodes in MANET function on battery power, which is a rare and limited energy resource. Hence, its conservation and utilization should be done judiciously for the effective functioning of the network. In this paper, a novel protocol namely Energy Reduction Multipath Routing Protocol for MANET using Recoil Technique (AOMDV-ER is proposed, which conserves the energy along with optimal network lifetime, routing overhead, packet delivery ratio and throughput. It performs better than any other AODV based algorithms, as in AOMDV-ER the nodes transmit packets to their destination smartly by using a varying recoil off time technique based on their geographical location. This concept reduces the number of transmissions, which results in the improvement of network lifetime. In addition, the local level route maintenance reduces the additional routing overhead. Lastly, the prediction based link lifetime of each node is estimated which helps in reducing the packet loss in the network. This protocol has three subparts: an optimal route discovery algorithm amalgamation with the residual energy and distance mechanism; a coordinated recoiled nodes algorithm which eliminates the number of transmissions in order to reduces the data redundancy, traffic redundant, routing overhead, end to end delay and enhance the network lifetime; and a last link reckoning and route maintenance algorithm to improve the packet delivery ratio and link stability in the network. The experimental results show that the AOMDV-ER protocol save at least 16% energy consumption, 12% reduction in routing overhead, significant achievement in network lifetime and packet delivery ratio than Ad hoc on demand multipath distance vector routing protocol (AOMDV, Ad hoc on demand multipath distance vector routing protocol life

  20. NAIL SAMPLING TECHNIQUE AND ITS INTERPRETATION

    Directory of Open Access Journals (Sweden)

    TZAR MN

    2011-01-01

    Full Text Available The clinical suspicion of onychomyosis based on appearance of the nails, requires culture for confirmation. This is because treatment requires prolonged use of systemic agents which may cause side effects. One of the common problems encountered is improper nail sampling technique which results in loss of essential information. The unfamiliar terminologies used in reporting culture results may intimidate physicians resulting in misinterpretation and hamper treatment decision. This article provides a simple guide on nail sampling technique and the interpretation of culture results.

  1. Microextraction sample preparation techniques in biomedical analysis.

    Science.gov (United States)

    Szultka, Malgorzata; Pomastowski, Pawel; Railean-Plugaru, Viorica; Buszewski, Boguslaw

    2014-11-01

    Biologically active compounds are found in biological samples at relatively low concentration levels. The sample preparation of target compounds from biological, pharmaceutical, environmental, and food matrices is one of the most time-consuming steps in the analytical procedure. The microextraction techniques are dominant. Metabolomic studies also require application of proper analytical technique for the determination of endogenic metabolites present in biological matrix on trace concentration levels. Due to the reproducibility of data, precision, relatively low cost of the appropriate analysis, simplicity of the determination, and the possibility of direct combination of those techniques with other methods (combination types on-line and off-line), they have become the most widespread in routine determinations. Additionally, sample pretreatment procedures have to be more selective, cheap, quick, and environmentally friendly. This review summarizes the current achievements and applications of microextraction techniques. The main aim is to deal with the utilization of different types of sorbents for microextraction and emphasize the use of new synthesized sorbents as well as to bring together studies concerning the systematic approach to method development. This review is dedicated to the description of microextraction techniques and their application in biomedical analysis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Protocol for Microplastics Sampling on the Sea Surface and Sample Analysis

    Science.gov (United States)

    Kovač Viršek, Manca; Palatinus, Andreja; Koren, Špela; Peterlin, Monika; Horvat, Petra; Kržan, Andrej

    2016-01-01

    Microplastic pollution in the marine environment is a scientific topic that has received increasing attention over the last decade. The majority of scientific publications address microplastic pollution of the sea surface. The protocol below describes the methodology for sampling, sample preparation, separation and chemical identification of microplastic particles. A manta net fixed on an »A frame« attached to the side of the vessel was used for sampling. Microplastic particles caught in the cod end of the net were separated from samples by visual identification and use of stereomicroscopes. Particles were analyzed for their size using an image analysis program and for their chemical structure using ATR-FTIR and micro FTIR spectroscopy. The described protocol is in line with recommendations for microplastics monitoring published by the Marine Strategy Framework Directive (MSFD) Technical Subgroup on Marine Litter. This written protocol with video guide will support the work of researchers that deal with microplastics monitoring all over the world. PMID:28060297

  3. NAIL SAMPLING TECHNIQUE AND ITS INTERPRETATION

    OpenAIRE

    TZAR MN; LEELAVATHI M

    2011-01-01

    The clinical suspicion of onychomyosis based on appearance of the nails, requires culture for confirmation. This is because treatment requires prolonged use of systemic agents which may cause side effects. One of the common problems encountered is improper nail sampling technique which results in loss of essential information. The unfamiliar terminologies used in reporting culture results may intimidate physicians resulting in misinterpretation and hamper treatment decision. This article prov...

  4. Sample size estimation and sampling techniques for selecting a representative sample

    Directory of Open Access Journals (Sweden)

    Aamir Omair

    2014-01-01

    Full Text Available Introduction: The purpose of this article is to provide a general understanding of the concepts of sampling as applied to health-related research. Sample Size Estimation: It is important to select a representative sample in quantitative research in order to be able to generalize the results to the target population. The sample should be of the required sample size and must be selected using an appropriate probability sampling technique. There are many hidden biases which can adversely affect the outcome of the study. Important factors to consider for estimating the sample size include the size of the study population, confidence level, expected proportion of the outcome variable (for categorical variables/standard deviation of the outcome variable (for numerical variables, and the required precision (margin of accuracy from the study. The more the precision required, the greater is the required sample size. Sampling Techniques: The probability sampling techniques applied for health related research include simple random sampling, systematic random sampling, stratified random sampling, cluster sampling, and multistage sampling. These are more recommended than the nonprobability sampling techniques, because the results of the study can be generalized to the target population.

  5. Protocol for sampling and analysis of bone specimens

    International Nuclear Information System (INIS)

    Aras, N.K.

    2000-01-01

    The iliac crest of hip bone was chosen as the most suitable sampling site for several reasons: Local variation in the elemental concentration along the iliac crest is minimal; Iliac crest biopsies are commonly taken clinically on patients; The cortical part of the sample is small (∼2 mm) and can be separated easily from the trabecular bone; The use of the trabecular part of the iliac crest for trace element analysis has the advantage of reflecting rapidly changes in the composition of bone due to external parameters, including medication. Biopsy studies, although in some ways more difficult than autopsy studies, because of the need to obtain the informed consents of the subjects, are potentially more useful than autopsy studies. Thereby many problems of postmortem migration of elements can be avoided and reliable dietary and other data can be collected simultaneously. Select the subjects among the patients undergoing orthopedic surgery due to any reason other than osteoporosis. Follow an established protocol to obtain bone biopsies. Patients undergoing synergy should fill in the 'Osteoporosis Project Questionnaire Form' including information on lifestyle variables, dietary intakes, the reason for surgery etc. If possible, measure the bone mineral density (BMD) prior to removal of the biopsy sample. However it may not possible to have BMD results on all the subjects because of difficulty of DEXA measurement after an accident

  6. Agricultural Soil Spectral Response and Properties Assessment: Effects of Measurement Protocol and Data Mining Technique

    Directory of Open Access Journals (Sweden)

    Asa Gholizadeh

    2017-10-01

    Full Text Available Soil spectroscopy has shown to be a fast, cost-effective, environmentally friendly, non-destructive, reproducible and repeatable analytical technique. Soil components, as well as types of instruments, protocols, sampling methods, sample preparation, spectral acquisition techniques and analytical algorithms have a combined influence on the final performance. Therefore, it is important to characterize these differences and to introduce an effective approach in order to minimize the technical factors that alter reflectance spectra and consequent prediction. To quantify this alteration, a joint project between Czech University of Life Sciences Prague (CULS and Tel-Aviv University (TAU was conducted to estimate Cox, pH-H2O, pH-KCl and selected forms of Fe and Mn. Two different soil spectral measurement protocols and two data mining techniques were used to examine seventy-eight soil samples from five agricultural areas in different parts of the Czech Republic. Spectral measurements at both laboratories were made using different ASD spectroradiometers. The CULS protocol was based on employing a contact probe (CP spectral measurement scheme, while the TAU protocol was carried out using a CP measurement method, accompanied with the internal soil standard (ISS procedure. Two spectral datasets, acquired from different protocols, were both analyzed using partial least square regression (PLSR technique as well as the PARACUDA II®, a new data mining engine for optimizing PLSR models. The results showed that spectra based on the CULS setup (non-ISS demonstrated significantly higher albedo intensity and reflectance values relative to the TAU setup with ISS. However, the majority of statistics using the TAU protocol was not noticeably better than the CULS spectra. The paper also highlighted that under both measurement protocols, the PARACUDA II® engine proved to be a powerful tool for providing better results than PLSR. Such initiative is not only a way to

  7. Evaluation of storage and filtration protocols for alpine/subalpine lake water quality samples

    Science.gov (United States)

    John L. Korfmacher; Robert C. Musselman

    2007-01-01

    Many government agencies and other organizations sample natural alpine and subalpine surface waters using varying protocols for sample storage and filtration. Simplification of protocols would be beneficial if it could be shown that sample quality is unaffected. In this study, samples collected from low ionic strength waters in alpine and subalpine lake inlets...

  8. Evaluation of diesel particulate matter sampling techniques

    CSIR Research Space (South Africa)

    Pretorius, CJ

    2011-09-01

    Full Text Available The study evaluated diesel particulate matter (DPM) sampling methods used in the South African mining industry. The three-piece cassette respirable, open face and stopper sampling methods were compared with the SKC DPM cassette method to find a...

  9. Development of sampling techniques for ITER Type B radwaste

    International Nuclear Information System (INIS)

    Hong, Kwon Pyo; Kim, Sung Geun; Jung, Sang Hee; Oh, Wan Ho; Park, Myung Chul; Kim, Hee Moon; Ahn, Sang Bok

    2016-01-01

    There are several difficulties and limitation in sampling activities. As the Type B radwaste components are mostly metallic(mostly stainless steel) and bulk(∼ 1 m in size and ∼ 100 mm in thickness), it is difficult in taking samples from the surface of Type B radwaste by remote operation. But also, sampling should be performed without use of any liquid coolant to avoid the spread of contamination. And all sampling procedures are carried in the hot cell red zone with remote operation. Three kinds of sampling techniques are being developed. They are core sampling, chip sampling, and wedge sampling, which are the candidates of sampling techniques to be applied to ITER hot cell. Object materials for sampling are stainless steel or Cu alloy block in order to simulate ITER Type B radwaste. The best sampling technique for ITER Type B radwaste among the three sampling techniques will be suggested in several months after finishing the related experiment

  10. Development of sampling techniques for ITER Type B radwaste

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Kwon Pyo; Kim, Sung Geun; Jung, Sang Hee; Oh, Wan Ho; Park, Myung Chul; Kim, Hee Moon; Ahn, Sang Bok [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    There are several difficulties and limitation in sampling activities. As the Type B radwaste components are mostly metallic(mostly stainless steel) and bulk(∼ 1 m in size and ∼ 100 mm in thickness), it is difficult in taking samples from the surface of Type B radwaste by remote operation. But also, sampling should be performed without use of any liquid coolant to avoid the spread of contamination. And all sampling procedures are carried in the hot cell red zone with remote operation. Three kinds of sampling techniques are being developed. They are core sampling, chip sampling, and wedge sampling, which are the candidates of sampling techniques to be applied to ITER hot cell. Object materials for sampling are stainless steel or Cu alloy block in order to simulate ITER Type B radwaste. The best sampling technique for ITER Type B radwaste among the three sampling techniques will be suggested in several months after finishing the related experiment.

  11. 21 CFR 660.6 - Samples; protocols; official release.

    Science.gov (United States)

    2010-04-01

    ... product iodinated with 125I means a sample from each lot of diagnostic test kits in a finished package... manufacturer has satisfactorily completed all tests on the samples: (i) One sample until written notification... of this section, a sample of product not iodinated with 125I means a sample from each filling of each...

  12. A multigear protocol for sampling crayfish assemblages in Gulf of Mexico coastal streams

    Science.gov (United States)

    William R. Budnick; William E. Kelso; Susan B. Adams; Michael D. Kaller

    2018-01-01

    Identifying an effective protocol for sampling crayfish in streams that vary in habitat and physical/chemical characteristics has proven problematic. We evaluated an active, combined-gear (backpack electrofishing and dipnetting) sampling protocol in 20 Coastal Plain streams in Louisiana. Using generalized linear models and rarefaction curves, we evaluated environmental...

  13. Nuclear techniques for analysis of environmental samples

    International Nuclear Information System (INIS)

    1986-12-01

    The main purposes of this meeting were to establish the state-of-the-art in the field, to identify new research and development that is required to provide an adequate framework for analysis of environmental samples and to assess needs and possibilities for international cooperation in problem areas. This technical report was prepared on the subject based on the contributions made by the participants. A separate abstract was prepared for each of the 9 papers

  14. Martian regolith geochemistry and sampling techniques

    Science.gov (United States)

    Clark, B. C.

    Laboratory study of samples of the intermediate and fine-grained regolith, including duricrust peds, is a fundamental prerequisite for understanding the types of physical and chemical weathering processes on Mars. The extraordinary importance of such samples is their relevance to understanding past changes in climate, availability (and possible physical state) of water, eolian forces, the thermal and chemical influences of volcanic and impact processes, and the inventory and fates of Martian volatiles. Fortunately, this regolith material appears to be ubiquitous over the Martian surface, and should be available at many different landing sites. Viking data has been interpreted to indicate a smectite-rich regolith material, implying extensive weathering involving aqueous activity and geochemical alteration. An all-igneous source of the Martian fines has also been proposed. The X-ray fluorescence measurement data set can now be fully explained in terms of a simple two-component model. The first component is silicate, having strong geochemical similarities with Shergottites, but not other SNC meteorites. The second component is salt. Variations in these components could produce silicate and salt-rich beds, the latter being of high potential importance for microenvironments in which liquid water (brines) could exist. It therefore would be desirable to scan the surface of the regolith for such prospects.

  15. Martian regolith geochemistry and sampling techniques

    Science.gov (United States)

    Clark, B. C.

    1988-01-01

    Laboratory study of samples of the intermediate and fine-grained regolith, including duricrust peds, is a fundamental prerequisite for understanding the types of physical and chemical weathering processes on Mars. The extraordinary importance of such samples is their relevance to understanding past changes in climate, availability (and possible physical state) of water, eolian forces, the thermal and chemical influences of volcanic and impact processes, and the inventory and fates of Martian volatiles. Fortunately, this regolith material appears to be ubiquitous over the Martian surface, and should be available at many different landing sites. Viking data has been interpreted to indicate a smectite-rich regolith material, implying extensive weathering involving aqueous activity and geochemical alteration. An all-igneous source of the Martian fines has also been proposed. The X-ray fluorescence measurement data set can now be fully explained in terms of a simple two-component model. The first component is silicate, having strong geochemical similarities with Shergottites, but not other SNC meteorites. The second component is salt. Variations in these components could produce silicate and salt-rich beds, the latter being of high potential importance for microenvironments in which liquid water (brines) could exist. It therefore would be desirable to scan the surface of the regolith for such prospects.

  16. A comparative study of sampling techniques for monitoring carcass contamination

    NARCIS (Netherlands)

    Snijders, J.M.A.; Janssen, M.H.W.; Gerats, G.E.; Corstiaensen, G.P.

    1984-01-01

    Four bacteriological sampling techniques i.e. the excision, double swab, agar contract and modified agar contact techniques were compared by sampling pig carcasses before and after chilling. As well as assessing the advantages and disadvantages of the techniques particular attention was paid to

  17. Petrosal sinus sampling: technique and rationale.

    Science.gov (United States)

    Miller, D L; Doppman, J L

    1991-01-01

    Bilateral simultaneous sampling of the inferior petrosal sinuses is an extremely sensitive, specific, and accurate test for diagnosing Cushing disease and distinguishing between that entity and the ectopic ACTH syndrome. It is also valuable for lateralizing small hormone-producing adenomas within the pituitary gland. The inferior petrosal sinuses connect the cavernous sinuses with the ipsilateral internal jugular veins. The anatomy of the anastomoses between the inferior petrosal sinus, the internal jugular vein, and the venous plexuses at the base of the skull varies, but it is almost always possible to catheterize the inferior petrosal sinus. In addition, variations in size and anatomy are often present between the two inferior petrosal sinuses in a patient. Advance preparation is required for petrosal sinus sampling. Teamwork is a critical element, and each member of the staff should know what he or she will be doing during the procedure. The samples must be properly labeled, processed, and stored. Specific needles, guide wires, and catheters are recommended for this procedure. The procedure is performed with specific attention to the three areas of potential technical difficulty: catheterization of the common femoral veins, crossing the valve at the base of the left internal jugular vein, and selective catheterization of the inferior petrosal sinuses. There are specific methods for dealing with each of these areas. The sine qua non of correct catheter position in the inferior petrosal sinus is demonstration of reflux of contrast material into the ipsilateral cavernous sinus. Images must always be obtained to document correct catheter position. Special attention must be paid to two points to prevent potential complications: The patient must be given an adequate dose of heparin, and injection of contrast material into the inferior petrosal sinuses and surrounding veins must be done gently and carefully. When the procedure is performed as outlined, both inferior

  18. Innovative directional and position specific sampling technique

    International Nuclear Information System (INIS)

    Hutzel, W.J.; Hill, J.L. III; Foster, E.L.

    1994-01-01

    UTD, Incorporated has developed a unique real-time, in-situ POsition LOcation (POLO) device which will directly enhance the Department of Energy's Environmental Restoration and Waste Management Program through improvements to finding contamination, identifying extent of contamination, remediating, and finally monitoring sites. POLO is smaller than existing technology and is unaffected by the presence of steel and other magnetic materials. The size of the device offers for the first time, the possibility to accurately determine the location of a penetrometer. It will be usable, in its present form, to map the position of a sampling device as that device is inserted into the ground. A three phase program was proposed to DOE to take the POLO System through the three levels of maturity prior to commercialization. Phase 1 included the design and testing of individual components of the device and met or exceeded success criteria. Phase 2 has included laboratory-scale tracking experiments of the integrated POLO System that have met or exceeded the success criterion as well. The success criterion is to demonstrate path tracking accuracy with a total error of less than 0.50% of the distance traveled for distances less than 70 meters. In Phase 3 we will develop and test a full-scale POLO System and conclude with a field demonstration. The goal of the Phase 3 effort is to achieve the same 0.50% accuracy or better with respect to the distance traveled for distances less than 70 meters in the field as was demonstrated in laboratory tests in the earlier phases. The final report details the design of a realistic laboratory-scale penetrometer path and describes the POLO tracking experiments that were conducted. Plans for demonstrations as well as commercialization and technology transfer with DOE field sites are described, highlighting the expected smooth transition to full-scale production

  19. Protocol for Cohesionless Sample Preparation for Physical Experimentation

    Science.gov (United States)

    2016-05-01

    Standard test method for consolidated drained triaxial compression test for soils . In Annual book of ASTM standards. West Conshohocken, PA: ASTM...derived wherein uncertainties and laboratory scatter associated with soil fabric-behavior variance during sample preparation are mitigated. Samples of...wherein comparable analysis between different laboratory tests’ results can be made by ensuring a comparable soil fabric prior to laboratory testing

  20. Lead Sampling Protocols: Why So Many and What Do They Tell You?

    Science.gov (United States)

    Sampling protocols can be broadly categorized based on their intended purpose of 1) Pb regulatory compliance/corrosion control efficacy, 2) Pb plumbing source determination or Pb type identification, and 3) Pb exposure assessment. Choosing the appropriate protocol is crucial to p...

  1. Comparison of sampling techniques for use in SYVAC

    International Nuclear Information System (INIS)

    Dalrymple, G.J.

    1984-01-01

    The Stephen Howe review (reference TR-STH-1) recommended the use of a deterministic generator (DG) sampling technique for sampling the input values to the SYVAC (SYstems Variability Analysis Code) program. This technique was compared with Monte Carlo simple random sampling (MC) by taking a 1000 run case of SYVAC using MC as the reference case. The results show that DG appears relatively inaccurate for most values of consequence when used with 11 sample intervals. If 22 sample intervals are used then DG generates cumulative distribution functions that are statistically similar to the reference distribution. 400 runs of DG or MC are adequate to generate a representative cumulative distribution function. The MC technique appears to perform better than DG for the same number of runs. However, the DG predicts higher doses and in view of the importance of generating data in the high dose region this sampling technique with 22 sample intervals is recommended for use in SYVAC. (author)

  2. Boat sampling technique for assessment of ageing of components

    International Nuclear Information System (INIS)

    Kumar, Kundan; Shyam, T.V.; Kayal, J.N.; Rupani, B.B.

    2006-01-01

    Boat sampling technique (BST) is a surface sampling technique, which has been developed for obtaining, in-situ, metal samples from the surface of an operating component without affecting its operating service life. The BST is non-destructive in nature and the sample is obtained without plastic deformation or without thermal degradation of the parent material. The shape and size of the sample depends upon the shape of the cutter and the surface geometry of the parent material. Miniature test specimens are generated from the sample and the specimens are subjected to various tests, viz. Metallurgical Evaluation, Metallographic Evaluation, Micro-hardness Evaluation, sensitisation test, small punch test etc. to confirm the integrity and assessment of safe operating life of the component. This paper highlights design objective of boat sampling technique, description of sampling module, sampling cutter and its performance evaluation, cutting process, boat samples, operational sequence of sampling module, qualification of sampling module, qualification of sampling technique, qualification of scooped region of the parent material, sample retrieval system, inspection, testing and examination to be carried out on the boat samples and scooped region. (author)

  3. Protocol and the post-human performativity of security techniques.

    Science.gov (United States)

    O'Grady, Nathaniel

    2016-07-01

    This article explores the deployment of exercises by the United Kingdom Fire and Rescue Service. Exercises stage, simulate and act out potential future emergencies and in so doing help the Fire and Rescue Service prepare for future emergencies. Specifically, exercises operate to assess and develop protocol; sets of guidelines which plan out the actions undertaken by the Fire and Rescue Service in responding to a fire. In the article I outline and assess the forms of knowledge and technologies, what I call the 'aesthetic forces', by which the exercise makes present and imagines future emergencies. By critically engaging with Karen Barad's notion of post-human performativity, I argue that exercises provide a site where such forces can entangle with one another; creating a bricolage through which future emergencies are evoked sensually and representatively, ultimately making it possible to experience emergencies in the present. This understanding of exercises allows also for critical appraisal of protocol both as phenomena that are produced through the enmeshing of different aesthetic forces and as devices which premise the operation of the security apparatus on contingency.

  4. PROTOCOL FOR GAS SAMPLING AND ANALYSIS IN STRANDED MARINE MAMMALS

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Yara Bernaldo de Quirós, Óscar González-Díaz, Manuel Arbelo, Marisa Andrada & Antonio Fernández ### Abstract Gas sampling in stranded marine mammals can now be performed in situ using the appropriate vacuum tubes, insulin syringes and an aspirometer. Glass vacuum tubes are used for extraction of gas from cavities such as the intestine, pterigoyd air sacs, pneumothorax or subcapsular emphysema as well as for storage of the gas sample at room temperature and pressure. Insulin s...

  5. Energy neutral protocol based on hierarchical routing techniques for energy harvesting wireless sensor network

    Science.gov (United States)

    Muhammad, Umar B.; Ezugwu, Absalom E.; Ofem, Paulinus O.; Rajamäki, Jyri; Aderemi, Adewumi O.

    2017-06-01

    Recently, researchers in the field of wireless sensor networks have resorted to energy harvesting techniques that allows energy to be harvested from the ambient environment to power sensor nodes. Using such Energy harvesting techniques together with proper routing protocols, an Energy Neutral state can be achieved so that sensor nodes can run perpetually. In this paper, we propose an Energy Neutral LEACH routing protocol which is an extension to the traditional LEACH protocol. The goal of the proposed protocol is to use Gateway node in each cluster so as to reduce the data transmission ranges of cluster head nodes. Simulation results show that the proposed routing protocol achieves a higher throughput and ensure the energy neutral status of the entire network.

  6. A modified FASP protocol for high-throughput preparation of protein samples for mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Jeremy Potriquet

    Full Text Available To facilitate high-throughput proteomic analyses we have developed a modified FASP protocol which improves the rate at which protein samples can be processed prior to mass spectrometry. Adapting the original FASP protocol to a 96-well format necessitates extended spin times for buffer exchange due to the low centrifugation speeds tolerated by these devices. However, by using 96-well plates with a more robust polyethersulfone molecular weight cutoff membrane, instead of the cellulose membranes typically used in these devices, we could use isopropanol as a wetting agent, decreasing spin times required for buffer exchange from an hour to 30 minutes. In a typical work flow used in our laboratory this equates to a reduction of 3 hours per plate, providing processing times similar to FASP for the processing of up to 96 samples per plate. To test whether our modified protocol produced similar results to FASP and other FASP-like protocols we compared the performance of our modified protocol to the original FASP and the more recently described eFASP and MStern-blot. We show that all FASP-like methods, including our modified protocol, display similar performance in terms of proteins identified and reproducibility. Our results show that our modified FASP protocol is an efficient method for the high-throughput processing of protein samples for mass spectral analysis.

  7. New trends in sample preparation techniques for environmental analysis.

    Science.gov (United States)

    Ribeiro, Cláudia; Ribeiro, Ana Rita; Maia, Alexandra S; Gonçalves, Virgínia M F; Tiritan, Maria Elizabeth

    2014-01-01

    Environmental samples include a wide variety of complex matrices, with low concentrations of analytes and presence of several interferences. Sample preparation is a critical step and the main source of uncertainties in the analysis of environmental samples, and it is usually laborious, high cost, time consuming, and polluting. In this context, there is increasing interest in developing faster, cost-effective, and environmentally friendly sample preparation techniques. Recently, new methods have been developed and optimized in order to miniaturize extraction steps, to reduce solvent consumption or become solventless, and to automate systems. This review attempts to present an overview of the fundamentals, procedure, and application of the most recently developed sample preparation techniques for the extraction, cleanup, and concentration of organic pollutants from environmental samples. These techniques include: solid phase microextraction, on-line solid phase extraction, microextraction by packed sorbent, dispersive liquid-liquid microextraction, and QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe).

  8. Urine sampling techniques in symptomatic primary-care patients

    DEFF Research Database (Denmark)

    Holm, Anne; Aabenhus, Rune

    2016-01-01

    in infection rate between mid-stream-clean-catch, mid-stream-urine and random samples. Conclusions: At present, no evidence suggests that sampling technique affects the accuracy of the microbiological diagnosis in non-pregnant women with symptoms of urinary tract infection in primary care. However......Background: Choice of urine sampling technique in urinary tract infection may impact diagnostic accuracy and thus lead to possible over- or undertreatment. Currently no evidencebased consensus exists regarding correct sampling technique of urine from women with symptoms of urinary tract infection...... a randomized or paired design to compare the result of urine culture obtained with two or more collection techniques in adult, female, non-pregnant patients with symptoms of urinary tract infection. We evaluated quality of the studies and compared accuracy based on dichotomized outcomes. Results: We included...

  9. Cleaning and Cleanliness Verification Techniques for Mars Returned Sample Handling

    Science.gov (United States)

    Mickelson, E. T.; Lindstrom, D. J.; Allton, J. H.; Hittle, J. D.

    2002-01-01

    Precision cleaning and cleanliness verification techniques are examined as a subset of a comprehensive contamination control strategy for a Mars sample return mission. Additional information is contained in the original extended abstract.

  10. Imaging techniques and investigation protocols in pediatric emergency imaging

    International Nuclear Information System (INIS)

    Scharitzer, M.; Hoermann, M.; Puig, S.; Prokop, M.

    2002-01-01

    Paediatric emergencies demand a quick and efficient radiological investigation with special attention to specific adjustments related to patient age and radiation protection. Imaging modalities are improving rapidly and enable to diagnose childhood diseases and injuries more quickly, accurately and safely. This article provides an overview of imaging techniques adjusted to the age of the child and an overview of imaging strategies of common paediatric emergencies. Optimising the imaging parameters (digital radiography, different screen-film systems, exposure specifications) allows for substantial reduction of radiation dose. Spiral- and multislice-CT reduce scan time and enable a considerable reduction of radiation exposure if scanning parameters (pitch setting, tube current) are properly adjusted. MRI is still mainly used for neurological or spinal emergencies despite the advent of fast imaging sequences. The radiologist's task is to select an appropriate imaging strategy according to expected differential diagnosis and to adjust the imaging techniques to the individual patient. (orig.) [de

  11. The general protocol for the S10 technique

    Directory of Open Access Journals (Sweden)

    Mircea Constantin Șora

    2016-12-01

    Full Text Available Plastination is a process of preservation of anatomical specimens by a delicate method of forced impregnation with curable polymers like silicone, epoxy or polyester resins, with vast applications in medical fields of study. In this process, water and lipids in biological tissues are replaced by curable polymers (silicone, epoxy, polyester which are hardened, resulting in dry, odorless and durable specimens. Today, after more than 30 years of its development, plastination is being applied in more than 400 departments of anatomy, pathology, forensic sciences and biology all over the world. The standard S10 silicone technique produces flexible, resilient and opaque specimens. After fixation and dehydration, the specimens are impregnated with silicone S10 and in the end the specimens are cured. The key element in plastination is the impregnation step and therefore depending on the polymer used the optical quality of the specimens differ. The S10 silicone technique is the most common technique used in plastination. It is used worldwide for beginners, but also for experimented plastinators. The S10 plastinated specimens can be easily stored at room temperature, are non-toxic and odorless. The S10 specimens can be successfully used, especially in teaching, as they are easy to be handled and display a realistic topography. Plastinated specimens are also used for displaying whole bodies, or body parts in exhibition.

  12. Pilot studies for the North American Soil Geochemical Landscapes Project - Site selection, sampling protocols, analytical methods, and quality control protocols

    Science.gov (United States)

    Smith, D.B.; Woodruff, L.G.; O'Leary, R. M.; Cannon, W.F.; Garrett, R.G.; Kilburn, J.E.; Goldhaber, M.B.

    2009-01-01

    In 2004, the US Geological Survey (USGS) and the Geological Survey of Canada sampled and chemically analyzed soils along two transects across Canada and the USA in preparation for a planned soil geochemical survey of North America. This effort was a pilot study to test and refine sampling protocols, analytical methods, quality control protocols, and field logistics for the continental survey. A total of 220 sample sites were selected at approximately 40-km intervals along the two transects. The ideal sampling protocol at each site called for a sample from a depth of 0-5 cm and a composite of each of the O, A, and C horizons. The Ca, Fe, K, Mg, Na, S, Ti, Ag, As, Ba, Be, Bi, Cd, Ce, Co, Cr, Cs, Cu, Ga, In, La, Li, Mn, Mo, Nb, Ni, P, Pb, Rb, Sb, Sc, Sn, Sr, Te, Th, Tl, U, V, W, Y, and Zn by inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectrometry following a near-total digestion in a mixture of HCl, HNO3, HClO4, and HF. Separate methods were used for Hg, Se, total C, and carbonate-C on this same size fraction. Only Ag, In, and Te had a large percentage of concentrations below the detection limit. Quality control (QC) of the analyses was monitored at three levels: the laboratory performing the analysis, the USGS QC officer, and the principal investigator for the study. This level of review resulted in an average of one QC sample for every 20 field samples, which proved to be minimally adequate for such a large-scale survey. Additional QC samples should be added to monitor within-batch quality to the extent that no more than 10 samples are analyzed between a QC sample. Only Cr (77%), Y (82%), and Sb (80%) fell outside the acceptable limits of accuracy (% recovery between 85 and 115%) because of likely residence in mineral phases resistant to the acid digestion. A separate sample of 0-5-cm material was collected at each site for determination of organic compounds. A subset of 73 of these samples was analyzed for a suite of

  13. Micro and Nano Techniques for the Handling of Biological Samples

    DEFF Research Database (Denmark)

    Micro and Nano Techniques for the Handling of Biological Samples reviews the different techniques available to manipulate and integrate biological materials in a controlled manner, either by sliding them along a surface (2-D manipulation), or by gripping and moving them to a new position (3-D...

  14. Non-terminal blood sampling techniques in guinea pigs.

    Science.gov (United States)

    Birck, Malene M; Tveden-Nyborg, Pernille; Lindblad, Maiken M; Lykkesfeldt, Jens

    2014-10-11

    Guinea pigs possess several biological similarities to humans and are validated experimental animal models(1-3). However, the use of guinea pigs currently represents a relatively narrow area of research and descriptive data on specific methodology is correspondingly scarce. The anatomical features of guinea pigs are slightly different from other rodent models, hence modulation of sampling techniques to accommodate for species-specific differences, e.g., compared to mice and rats, are necessary to obtain sufficient and high quality samples. As both long and short term in vivo studies often require repeated blood sampling the choice of technique should be well considered in order to reduce stress and discomfort in the animals but also to ensure survival as well as compliance with requirements of sample size and accessibility. Venous blood samples can be obtained at a number of sites in guinea pigs e.g., the saphenous and jugular veins, each technique containing both advantages and disadvantages(4,5). Here, we present four different blood sampling techniques for either conscious or anaesthetized guinea pigs. The procedures are all non-terminal procedures provided that sample volumes and number of samples do not exceed guidelines for blood collection in laboratory animals(6). All the described methods have been thoroughly tested and applied for repeated in vivo blood sampling in studies within our research facility.

  15. Sampling techniques for thrips (Thysanoptera: Thripidae) in preflowering tomato.

    Science.gov (United States)

    Joost, P Houston; Riley, David G

    2004-08-01

    Sampling techniques for thrips (Thysanoptera: Thripidae) were compared in preflowering tomato plants at the Coastal Plain Experiment Station in Tifton, GA, in 2000 and 2003, to determine the most effective method of determining abundance of thrips on tomato foliage early in the growing season. Three relative sampling techniques, including a standard insect aspirator, a 946-ml beat cup, and an insect vacuum device, were compared for accuracy to an absolute method and to themselves for precision and efficiency of sampling thrips. Thrips counts of all relative sampling methods were highly correlated (R > 0.92) to the absolute method. The aspirator method was the most accurate compared with the absolute sample according to regression analysis in 2000. In 2003, all sampling methods were considered accurate according to Dunnett's test, but thrips numbers were lower and sample variation was greater than in 2000. In 2000, the beat cup method had the lowest relative variation (RV) or best precision, at 1 and 8 d after transplant (DAT). Only the beat cup method had RV values <25 for all sampling dates. In 2003, the beat cup method had the lowest RV value at 15 and 21 DAT. The beat cup method also was the most efficient method for all sample dates in both years. Frankliniella fusca (Pergande) was the most abundant thrips species on the foliage of preflowering tomato in both years of study at this location. Overall, the best thrips sampling technique tested was the beat cup method in terms of precision and sampling efficiency.

  16. Differences in sampling techniques on total post-mortem tryptase.

    Science.gov (United States)

    Tse, R; Garland, J; Kesha, K; Elstub, H; Cala, A D; Ahn, Y; Stables, S; Palmiere, C

    2017-11-20

    The measurement of mast cell tryptase is commonly used to support the diagnosis of anaphylaxis. In the post-mortem setting, the literature recommends sampling from peripheral blood sources (femoral blood) but does not specify the exact sampling technique. Sampling techniques vary between pathologists, and it is unclear whether different sampling techniques have any impact on post-mortem tryptase levels. The aim of this study is to compare the difference in femoral total post-mortem tryptase levels between two sampling techniques. A 6-month retrospective study comparing femoral total post-mortem tryptase levels between (1) aspirating femoral vessels with a needle and syringe prior to evisceration and (2) femoral vein cut down during evisceration. Twenty cases were identified, with three cases excluded from analysis. There was a statistically significant difference (paired t test, p sampling methods. The clinical significance of this finding and what factors may contribute to it are unclear. When requesting post-mortem tryptase, the pathologist should consider documenting the exact blood collection site and method used for collection. In addition, blood samples acquired by different techniques should not be mixed together and should be analyzed separately if possible.

  17. Protocol of measurement techniques - Project colored solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J.-L.

    2004-08-15

    This illustrated annual report for the Swiss Federal Office of Energy (SFOE) takes a look at work done at the Swiss Federal Institute of Technology in Lausanne, Switzerland, on multi-layer, thin-film interference coatings for solar collector glazing. The correct combinations of refractive indices and film thickness are discussed. The authors state that corresponding multi-layered thin film stacks will have to be realised experimentally in a controlled and reproducible way. New thin film materials are to be tailored to exhibit optimised optical and ageing properties. The development of these coatings is to be based on various measurement techniques, such as spectro-photometry, measurements of total power throughput by means of a solar simulator, spectroscopic ellipsometry, scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The paper provides many examples of typical data and explains which film properties can be inferred from each method and thus describes both the function and purpose of the different measurement techniques.

  18. The Gas Sampling Interval Effect on V˙O2peak Is Independent of Exercise Protocol.

    Science.gov (United States)

    Scheadler, Cory M; Garver, Matthew J; Hanson, Nicholas J

    2017-09-01

    There is a plethora of gas sampling intervals available during cardiopulmonary exercise testing to measure peak oxygen consumption (V˙O2peak). Different intervals can lead to altered V˙O2peak. Whether differences are affected by the exercise protocol or subject sample is not clear. The purpose of this investigation was to determine whether V˙O2peak differed because of the manipulation of sampling intervals and whether differences were independent of the protocol and subject sample. The first subject sample (24 ± 3 yr; V˙O2peak via 15-breath moving averages: 56.2 ± 6.8 mL·kg·min) completed the Bruce and the self-paced V˙O2max protocols. The second subject sample (21.9 ± 2.7 yr; V˙O2peak via 15-breath moving averages: 54.2 ± 8.0 mL·kg·min) completed the Bruce and the modified Astrand protocols. V˙O2peak was identified using five sampling intervals: 15-s block averages, 30-s block averages, 15-breath block averages, 15-breath moving averages, and 30-s block averages aligned to the end of exercise. Differences in V˙O2peak between intervals were determined using repeated-measures ANOVAs. The influence of subject sample on the sampling effect was determined using independent t-tests. There was a significant main effect of sampling interval on V˙O2peak (first sample Bruce and self-paced V˙O2max P sample Bruce and modified Astrand P sampling intervals followed a similar pattern for each protocol and subject sample, with 15-breath moving average presenting the highest V˙O2peak. The effect of manipulating gas sampling intervals on V˙O2peak appears to be protocol and sample independent. These findings highlight our recommendation that the clinical and scientific community request and report the sampling interval whenever metabolic data are presented. The standardization of reporting would assist in the comparison of V˙O2peak.

  19. Reducing the sampling periods required in protocols for establishing ammonia emissions from pig fattening buildings using measurements and modelling

    NARCIS (Netherlands)

    Mosquera Losada, J.; Ogink, N.W.M.

    2011-01-01

    Ammonia (NH(3)) emission factors for animal housing systems in the Netherlands are based on measurements using standardised measurement protocols. Both the original Green Label (GL) protocol and the newly developed multi-site sampling protocol are based on year-round sampling periods. The objective

  20. Optimization of a sample processing protocol for recovery of Bacillus anthracis spores from soil

    Science.gov (United States)

    Silvestri, Erin E.; Feldhake, David; Griffin, Dale; Lisle, John T.; Nichols, Tonya L.; Shah, Sanjiv; Pemberton, A; Schaefer III, Frank W

    2016-01-01

    Following a release of Bacillus anthracis spores into the environment, there is a potential for lasting environmental contamination in soils. There is a need for detection protocols for B. anthracis in environmental matrices. However, identification of B. anthracis within a soil is a difficult task. Processing soil samples helps to remove debris, chemical components, and biological impurities that can interfere with microbiological detection. This study aimed to optimize a previously used indirect processing protocol, which included a series of washing and centrifugation steps. Optimization of the protocol included: identifying an ideal extraction diluent, variation in the number of wash steps, variation in the initial centrifugation speed, sonication and shaking mechanisms. The optimized protocol was demonstrated at two laboratories in order to evaluate the recovery of spores from loamy and sandy soils. The new protocol demonstrated an improved limit of detection for loamy and sandy soils over the non-optimized protocol with an approximate matrix limit of detection at 14 spores/g of soil. There were no significant differences overall between the two laboratories for either soil type, suggesting that the processing protocol will be robust enough to use at multiple laboratories while achieving comparable recoveries.

  1. Non-terminal blood sampling techniques in Guinea pigs

    DEFF Research Database (Denmark)

    Birck, Malene Muusfeldt; Tveden-Nyborg, Pernille; Lindblad, Maiken Marie

    2014-01-01

    Guinea pigs possess several biological similarities to humans and are validated experimental animal models(1-3). However, the use of guinea pigs currently represents a relatively narrow area of research and descriptive data on specific methodology is correspondingly scarce. The anatomical features...... of guinea pigs are slightly different from other rodent models, hence modulation of sampling techniques to accommodate for species-specific differences, e.g., compared to mice and rats, are necessary to obtain sufficient and high quality samples. As both long and short term in vivo studies often require...... repeated blood sampling the choice of technique should be well considered in order to reduce stress and discomfort in the animals but also to ensure survival as well as compliance with requirements of sample size and accessibility. Venous blood samples can be obtained at a number of sites in guinea pigs e...

  2. Water sampling techniques for continuous monitoring of pesticides in water

    Directory of Open Access Journals (Sweden)

    Šunjka Dragana

    2017-01-01

    Full Text Available Good ecological and chemical status of water represents the most important aim of the Water Framework Directive 2000/60/EC, which implies respect of water quality standards at the level of entire river basin (2008/105/EC and 2013/39/EC. This especially refers to the control of pesticide residues in surface waters. In order to achieve the set goals, a continuous monitoring program that should provide a comprehensive and interrelated overview of water status should be implemented. However, it demands the use of appropriate analysis techniques. Until now, the procedure for sampling and quantification of residual pesticide quantities in aquatic environment was based on the use of traditional sampling techniques that imply periodical collecting of individual samples. However, this type of sampling provides only a snapshot of the situation in regard to the presence of pollutants in water. As an alternative, the technique of passive sampling of pollutants in water, including pesticides has been introduced. Different samplers are available for pesticide sampling in surface water, depending on compounds. The technique itself is based on keeping a device in water over a longer period of time which varies from several days to several weeks, depending on the kind of compound. In this manner, the average concentrations of pollutants dissolved in water during a time period (time-weighted average concentrations, TWA are obtained, which enables monitoring of trends in areal and seasonal variations. The use of these techniques also leads to an increase in sensitivity of analytical methods, considering that pre-concentration of analytes takes place within the sorption medium. However, the use of these techniques for determination of pesticide concentrations in real water environments requires calibration studies for the estimation of sampling rates (Rs. Rs is a volume of water per time, calculated as the product of overall mass transfer coefficient and area of

  3. Assessment of Natural Radioactivity in TENORM Samples Using Different Techniques

    International Nuclear Information System (INIS)

    Salman, Kh.A.; Shahein, A.Y.

    2009-01-01

    In petroleum oil industries, technologically-enhanced, naturally occurring radioactive materials are produced. The presence of TENORM constitutes a significant radiological human health hazard. In the present work, liquid scintillation counting technique was used to determine both 222 Rn and 226 Ra concentrations in TENORM samples, by measuring 222 Rn concentrations in the sample at different intervals of time after preparation. The radiation doses from the TENORM samples were estimated using thermoluminenscent detector (TLD-4000). The estimated radiation doses were found to be proportional to both the measured radiation doses in site and natural activity concentration in the samples that measured with LSC

  4. Application of the Sampling Selection Technique in Approaching Financial Audit

    Directory of Open Access Journals (Sweden)

    Victor Munteanu

    2018-03-01

    Full Text Available In his professional approach, the financial auditor has a wide range of working techniques, including selection techniques. They are applied depending on the nature of the information available to the financial auditor, the manner in which they are presented - paper or electronic format, and, last but not least, the time available. Several techniques are applied, successively or in parallel, to increase the safety of the expressed opinion and to provide the audit report with a solid basis of information. Sampling is used in the phase of control or clarification of the identified error. The main purpose is to corroborate or measure the degree of risk detected following a pertinent analysis. Since the auditor does not have time or means to thoroughly rebuild the information, the sampling technique can provide an effective response to the need for valorization.

  5. A Robust PCR Protocol for HIV Drug Resistance Testing on Low-Level Viremia Samples

    Directory of Open Access Journals (Sweden)

    Shivani Gupta

    2017-01-01

    Full Text Available The prevalence of drug resistance (DR mutations in people with HIV-1 infection, particularly those with low-level viremia (LLV, supports the need to improve the sensitivity of amplification methods for HIV DR genotyping in order to optimize antiretroviral regimen and facilitate HIV-1 DR surveillance and relevant research. Here we report on a fully validated PCR-based protocol that achieves consistent amplification of the protease (PR and reverse transcriptase (RT regions of HIV-1 pol gene across many HIV-1 subtypes from LLV plasma samples. HIV-spiked plasma samples from the External Quality Assurance Program Oversight Laboratory (EQAPOL, covering various HIV-1 subtypes, as well as clinical specimens were used to optimize and validate the protocol. Our results demonstrate that this protocol has a broad HIV-1 subtype coverage and viral load span with high sensitivity and reproducibility. Moreover, the protocol is robust even when plasma sample volumes are limited, the HIV viral load is unknown, and/or the HIV subtype is undetermined. Thus, the protocol is applicable for the initial amplification of the HIV-1 PR and RT genes required for subsequent genotypic DR assays.

  6. New materials for sample preparation techniques in bioanalysis.

    Science.gov (United States)

    Nazario, Carlos Eduardo Domingues; Fumes, Bruno Henrique; da Silva, Meire Ribeiro; Lanças, Fernando Mauro

    2017-02-01

    The analysis of biological samples is a complex and difficult task owing to two basic and complementary issues: the high complexity of most biological matrices and the need to determine minute quantities of active substances and contaminants in such complex sample. To succeed in this endeavor samples are usually subject to three steps of a comprehensive analytical methodological approach: sample preparation, analytes isolation (usually utilizing a chromatographic technique) and qualitative/quantitative analysis (usually with the aid of mass spectrometric tools). Owing to the complex nature of bio-samples, and the very low concentration of the target analytes to be determined, selective sample preparation techniques is mandatory in order to overcome the difficulties imposed by these two constraints. During the last decade new chemical synthesis approaches has been developed and optimized, such as sol-gel and molecularly imprinting technologies, allowing the preparation of novel materials for sample preparation including graphene and derivatives, magnetic materials, ionic liquids, molecularly imprinted polymers, and much more. In this contribution we will review these novel techniques and materials, as well as their application to the bioanalysis niche. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Establishment of a protocol for the gene expression analysis of laser microdissected rat kidney samples with affymetrix genechips

    International Nuclear Information System (INIS)

    Stemmer, Kerstin; Ellinger-Ziegelbauer, Heidrun; Lotz, Kerstin; Ahr, Hans-J.; Dietrich, Daniel R.

    2006-01-01

    Laser microdissection in conjunction with microarray technology allows selective isolation and analysis of specific cell populations, e.g., preneoplastic renal lesions. To date, only limited information is available on sample preparation and preservation techniques that result in both optimal histomorphological preservation of sections and high-quality RNA for microarray analysis. Furthermore, amplification of minute amounts of RNA from microdissected renal samples allowing analysis with genechips has only scantily been addressed to date. The objective of this study was therefore to establish a reliable and reproducible protocol for laser microdissection in conjunction with microarray technology using kidney tissue from Eker rats p.o. treated for 7 days and 6 months with 10 and 1 mg Aristolochic acid/kg bw, respectively. Kidney tissues were preserved in RNAlater or snap frozen. Cryosections were cut and stained with either H and E or cresyl violet for subsequent morphological and RNA quality assessment and laser microdissection. RNA quality was comparable in snap frozen and RNAlater-preserved samples, however, the histomorphological preservation of renal sections was much better following cryopreservation. Moreover, the different staining techniques in combination with sample processing time at room temperature can have an influence on RNA quality. Different RNA amplification protocols were shown to have an impact on gene expression profiles as demonstrated with Affymetrix Rat Genome 230 2 .0 arrays. Considering all the parameters analyzed in this study, a protocol for RNA isolation from laser microdissected samples with subsequent Affymetrix chip hybridization was established that was also successfully applied to preneoplastic lesions laser microdissected from Aristolochic acid-treated rats

  8. Sample preparation for special PIE-techniques at ITU

    International Nuclear Information System (INIS)

    Toscano, E.H.; Manzel, R.

    2002-01-01

    Several sample preparation techniques were developed and installed in hot cells. The techniques were conceived to evaluate the performance of highly burnt fuel rods and include: (a) a device for the removal of the fuel, (b) a method for the preparation of the specimen ends for the welding of new end caps and for the careful cleaning of samples for Transmission Electron Microscopy and Glow Discharge Mass Spectroscopy, (c) a sample pressurisation device for long term creep tests, and (d) a diameter measuring device for creep or burst samples. Examples of the determination of the mechanical properties, the behaviour under transient conditions and for the assessment of the corrosion behaviour of high burnup cladding materials are presented. (author)

  9. Use of nuclear technique in samples for agricultural purposes

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Kerley A. P. de; Sperling, Eduardo Von, E-mail: kerley@ufmg.br, E-mail: kerleyfisica@yahoo.com.br [Department of Sanitary and Environmental Engineering Federal University of Minas Gerais, Belo Horizonte (Brazil); Menezes, Maria Angela B. C.; Jacomino, Vanusa M.F. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-01-15

    The concern related to environment is growing. Due to this, it is needed to determine chemical elements in a large range of concentration. The neutron activation technique (NAA) determines the elemental composition by the measurement of artificial radioactivity in a sample that was submitted to a neutron flux. NAA is a sensitive and accurate technique with low detection limits. An example of application of NAA was the measurement of concentrations of rare earth elements (REE) in waste samples of phosphogypsum (PG) and cerrado soil samples (clayey and sandy soils). Additionally, a soil reference material of the International Atomic Energy Agency (IAEA) was also analyzed. The REE concentration in PG samples was two times higher than those found in national fertilizers, (total of 4,000 mg kg{sup -1}), 154 times greater than the values found in the sandy soil (26 mg kg{sup -1}) and 14 times greater than the in clayey soil (280 mg kg{sup -1}). The experimental results for the reference material were inside the uncertainty of the certified values pointing out the accuracy of the method (95%). The determination of La, Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb and Lu in the samples and reference material confirmed the versatility of the technique on REE determination in soil and phosphogypsum samples that are matrices for agricultural interest. (author)

  10. Development of analytical techniques for safeguards environmental samples at JAEA

    International Nuclear Information System (INIS)

    Sakurai, Satoshi; Magara, Masaaki; Usuda, Shigekazu; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, Chi-Gyu; Yasuda, Kenichiro; Inagawa, Jun; Suzuki, Daisuke; Iguchi, Kazunari; Kokubu, Yoko S.; Miyamoto, Yutaka; Ohzu, Akira

    2007-01-01

    JAEA has been developing, under the auspices of the Ministry of Education, Culture, Sports, Science and Technology of Japan, analytical techniques for ultra-trace amounts of nuclear materials in environmental samples in order to contribute to the strengthened safeguards system. Development of essential techniques for bulk and particle analysis, as well as screening, of the environmental swipe samples has been established as ultra-trace analytical methods of uranium and plutonium. In January 2003, JAEA was qualified, including its quality control system, as a member of the JAEA network analytical laboratories for environmental samples. Since 2004, JAEA has conducted the analysis of domestic and the IAEA samples, through which JAEA's analytical capability has been verified and improved. In parallel, advanced techniques have been developed in order to expand the applicability to the samples of various elemental composition and impurities and to improve analytical accuracy and efficiency. This paper summarizes the trace of the technical development in environmental sample analysis at JAEA, and refers to recent trends of research and development in this field. (author)

  11. Use of nuclear technique in samples for agricultural purposes

    International Nuclear Information System (INIS)

    Oliveira, Kerley A. P. de; Sperling, Eduardo Von; Menezes, Maria Angela B. C.; Jacomino, Vanusa M.F.

    2013-01-01

    The concern related to environment is growing. Due to this, it is needed to determine chemical elements in a large range of concentration. The neutron activation technique (NAA) determines the elemental composition by the measurement of artificial radioactivity in a sample that was submitted to a neutron flux. NAA is a sensitive and accurate technique with low detection limits. An example of application of NAA was the measurement of concentrations of rare earth elements (REE) in waste samples of phosphogypsum (PG) and cerrado soil samples (clayey and sandy soils). Additionally, a soil reference material of the International Atomic Energy Agency (IAEA) was also analyzed. The REE concentration in PG samples was two times higher than those found in national fertilizers, (total of 4,000 mg kg -1 ), 154 times greater than the values found in the sandy soil (26 mg kg -1 ) and 14 times greater than the in clayey soil (280 mg kg -1 ). The experimental results for the reference material were inside the uncertainty of the certified values pointing out the accuracy of the method (95%). The determination of La, Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb and Lu in the samples and reference material confirmed the versatility of the technique on REE determination in soil and phosphogypsum samples that are matrices for agricultural interest. (author)

  12. A Monte Carlo Sampling Technique for Multi-phonon Processes

    Energy Technology Data Exchange (ETDEWEB)

    Hoegberg, Thure

    1961-12-15

    A sampling technique for selecting scattering angle and energy gain in Monte Carlo calculations of neutron thermalization is described. It is supposed that the scattering is separated into processes involving different numbers of phonons. The number of phonons involved is first determined. Scattering angle and energy gain are then chosen by using special properties of the multi-phonon term.

  13. Comparison of sampling techniques for Rift Valley Fever virus ...

    African Journals Online (AJOL)

    We investigated mosquito sampling techniques with two types of traps and attractants at different time for trapping potential vectors for Rift Valley Fever virus. The study was conducted in six villages in Ngorongoro district in Tanzania from September to October 2012. A total of 1814 mosquitoes were collected, of which 738 ...

  14. Analytical techniques for measurement of 99Tc in environmental samples

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Three new methods have been developed for measuring 99 Tc in environmental samples. The most sensitive method is isotope dilution mass spectrometry, which allows measurement of about 1 x 10 -12 grams of 99 Tc. Results on analysis of five samples by this method compare very well with values obtained by a second independent method, which involves counting of beta particles from 99 Tc and internal conversion electrons from /sup 97m/Tc. A third method involving electrothermal atomic absorption has also been developed. Although this method is not as sensitive as the first two techniques, the cost per analysis is expected to be considerably less for certain types of samples

  15. Radioisotope Sample Measurement Techniques in Medicine and Biology. Proceedings of the Symposium on Radioisotope Sample Measurement Techniques

    International Nuclear Information System (INIS)

    1965-01-01

    The medical and biological applications of radioisotopes depend on two basically different types of measurements, those on living subjects in vivo and those on samples in vitro. The International Atomic Energy Agency has in the past held several meetings on in vivo measurement techniques, notably whole-body counting and radioisotope scanning. The present volume contains the Proceedings of the first Symposium the Agency has organized to discuss the various aspects of techniques for sample measurement in vitro. The range of these sample measurement techniques is very wide. The sample may weigh a few milligrams or several hundred grams, and may be in the gaseous, liquid or solid state. Its radioactive content may consist of a single, known radioisotope or several unknown ones. The concentration of radioactivity may be low, medium or high. The measurements may be made manually or automatically and any one of the many radiation detectors now available may be used. The 53 papers presented at the Symposium illustrate the great variety of methods now in use for radioactive- sample measurements. The first topic discussed is gamma-ray spectrometry, which finds an increasing number of applications in sample measurements. Other sections of the Proceedings deal with: the use of computers in gamma-ray spectrometry and multiple tracer techniques; recent developments in activation analysis where both gamma-ray spectrometry and computing techniques are applied; thin-layer and paper radio chromatographic techniques for use with low energy beta-ray emitters; various aspects of liquid scintillation counting techniques in the measurement of alpha- and beta-ray emitters, including chemical and colour quenching; autoradiographic techniques; calibration of equipment; and standardization of radioisotopes. Finally, some applications of solid-state detectors are presented; this section may be regarded as a preview of important future developments. The meeting was attended by 203 participants

  16. Application of digital sampling techniques to particle identification

    International Nuclear Information System (INIS)

    Bardelli, L.; Poggi, G.; Bini, M.; Carraresi, L.; Pasquali, G.; Taccetti, N.

    2003-01-01

    An application of digital sampling techniques is presented which can greatly simplify experiments involving sub-nanosecond time-mark determinations and energy measurements with nuclear detectors, used for Pulse Shape Analysis and Time of Flight measurements in heavy ion experiments. In this work a 100 M Sample/s, 12 bit analog to digital converter has been used: examples of this technique applied to Silicon and CsI(Tl) detectors in heavy-ions experiments involving particle identification via Pulse Shape analysis and Time of Flight measurements are presented. The system is suited for applications to large detector arrays and to different kinds of detectors. Some preliminary results regarding the simulation of current signals in Silicon detectors are also discussed. (authors)

  17. A rapid and efficient DNA extraction protocol from fresh and frozen human blood samples.

    Science.gov (United States)

    Guha, Pokhraj; Das, Avishek; Dutta, Somit; Chaudhuri, Tapas Kumar

    2018-01-01

    Different methods available for extraction of human genomic DNA suffer from one or more drawbacks including low yield, compromised quality, cost, time consumption, use of toxic organic solvents, and many more. Herein, we aimed to develop a method to extract DNA from 500 μL of fresh or frozen human blood. Five hundred microliters of fresh and frozen human blood samples were used for standardization of the extraction procedure. Absorbance at 260 and 280 nm, respectively, (A 260 /A 280 ) were estimated to check the quality and quantity of the extracted DNA sample. Qualitative assessment of the extracted DNA was checked by Polymerase Chain reaction and double digestion of the DNA sample. Our protocol resulted in average yield of 22±2.97 μg and 20.5±3.97 μg from 500 μL of fresh and frozen blood, respectively, which were comparable to many reference protocols and kits. Besides yielding bulk amount of DNA, our protocol is rapid, economical, and avoids toxic organic solvents such as Phenol. Due to unaffected quality, the DNA is suitable for downstream applications. The protocol may also be useful for pursuing basic molecular researches in laboratories having limited funds. © 2017 Wiley Periodicals, Inc.

  18. Development of core sampling technique for ITER Type B radwaste

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. G.; Hong, K. P.; Oh, W. H.; Park, M. C.; Jung, S. H.; Ahn, S. B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Type B radwaste (intermediate level and long lived radioactive waste) imported from ITER vacuum vessel are to be treated and stored in basement of hot cell building. The Type B radwaste treatment process is composed of buffer storage, cutting, sampling/tritium measurement, tritium removal, characterization, pre-packaging, inspection/decontamination, and storage etc. The cut slices of Type B radwaste components generated from cutting process undergo sampling process before and after tritium removal process. The purpose of sampling is to obtain small pieces of samples in order to investigate the tritium content and concentration of Type B radwaste. Core sampling, which is the candidates of sampling technique to be applied to ITER hot cell, is available for not thick (less than 50 mm) metal without use of coolant. Experimented materials were SS316L and CuCrZr in order to simulate ITER Type B radwaste. In core sampling, substantial secondary wastes from cutting chips will be produced unavoidably. Thus, core sampling machine will have to be equipped with disposal system such as suction equipment. Core sampling is considered an unfavorable method for tool wear compared to conventional drilling.

  19. Manipulation of biological samples using micro and nano techniques.

    Science.gov (United States)

    Castillo, Jaime; Dimaki, Maria; Svendsen, Winnie Edith

    2009-01-01

    The constant interest in handling, integrating and understanding biological systems of interest for the biomedical field, the pharmaceutical industry and the biomaterial researchers demand the use of techniques that allow the manipulation of biological samples causing minimal or no damage to their natural structure. Thanks to the advances in micro- and nanofabrication during the last decades several manipulation techniques offer us the possibility to image, characterize and manipulate biological material in a controlled way. Using these techniques the integration of biomaterials with remarkable properties with physical transducers has been possible, giving rise to new and highly sensitive biosensing devices. This article reviews the different techniques available to manipulate and integrate biological materials in a controlled manner either by sliding them along a surface (2-D manipulation), by grapping them and moving them to a new position (3-D manipulation), or by manipulating and relocating them applying external forces. The advantages and drawbacks are mentioned together with examples that reflect the state of the art of manipulation techniques for biological samples (171 references).

  20. Evaluation of sample preparation protocols for spider venom profiling by MALDI-TOF MS.

    Science.gov (United States)

    Bočánek, Ondřej; Šedo, Ondrej; Pekár, Stano; Zdráhal, Zbyněk

    2017-07-01

    Spider venoms are highly complex mixtures containing biologically active substances with potential for use in biotechnology or pharmacology. Fingerprinting of venoms by Matrix-Assisted Laser Desorption-Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS) is a thriving technology, enabling the rapid detection of peptide/protein components that can provide comparative information. In this study, we evaluated the effects of sample preparation procedures on MALDI-TOF mass spectral quality to establish a protocol providing the most reliable analytical outputs. We adopted initial sample preparation conditions from studies already published in this field. Three different MALDI matrixes, three matrix solvents, two sample deposition methods, and different acid concentrations were tested. As a model sample, venom from Brachypelma albopilosa was used. The mass spectra were evaluated on the basis of absolute and relative signal intensities, and signal resolution. By conducting three series of analyses at three weekly intervals, the reproducibility of the mass spectra were assessed as a crucial factor in the selection for optimum conditions. A sample preparation protocol based on the use of an HCCA matrix dissolved in 50% acetonitrile with 2.5% TFA deposited onto the target by the dried-droplet method was found to provide the best results in terms of information yield and repeatability. We propose that this protocol should be followed as a standard procedure, enabling the comparative assessment of MALDI-TOF MS spider venom fingerprints. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. A simplified field protocol for genetic sampling of birds using buccal swabs

    Science.gov (United States)

    Vilstrup, Julia T.; Mullins, Thomas D.; Miller, Mark P.; McDearman, Will; Walters, Jeffrey R.; Haig, Susan M.

    2018-01-01

    DNA sampling is an essential prerequisite for conducting population genetic studies. For many years, blood sampling has been the preferred method for obtaining DNA in birds because of their nucleated red blood cells. Nonetheless, use of buccal swabs has been gaining favor because they are less invasive yet still yield adequate amounts of DNA for amplifying mitochondrial and nuclear markers; however, buccal swab protocols often include steps (e.g., extended air-drying and storage under frozen conditions) not easily adapted to field settings. Furthermore, commercial extraction kits and swabs for buccal sampling can be expensive for large population studies. We therefore developed an efficient, cost-effective, and field-friendly protocol for sampling wild birds after comparing DNA yield among 3 inexpensive buccal swab types (2 with foam tips and 1 with a cotton tip). Extraction and amplification success was high (100% and 97.2% respectively) using inexpensive generic swabs. We found foam-tipped swabs provided higher DNA yields than cotton-tipped swabs. We further determined that omitting a drying step and storing swabs in Longmire buffer increased efficiency in the field while still yielding sufficient amounts of DNA for detailed population genetic studies using mitochondrial and nuclear markers. This new field protocol allows time- and cost-effective DNA sampling of juveniles or small-bodied birds for which drawing blood may cause excessive stress to birds and technicians alike.

  2. Determination of palladium in biological samples applying nuclear analytical techniques

    International Nuclear Information System (INIS)

    Cavalcante, Cassio Q.; Sato, Ivone M.; Salvador, Vera L. R.; Saiki, Mitiko

    2008-01-01

    This study presents Pd determinations in bovine tissue samples containing palladium prepared in the laboratory, and CCQM-P63 automotive catalyst materials of the Proficiency Test, using instrumental thermal and epithermal neutron activation analysis and energy dispersive X-ray fluorescence techniques. Solvent extraction and solid phase extraction procedures were also applied to separate Pd from interfering elements before the irradiation in the nuclear reactor. The results obtained by different techniques were compared against each other to examine sensitivity, precision and accuracy. (author)

  3. Reliability and criterion validity of an observation protocol for working technique assessments in cash register work.

    Science.gov (United States)

    Palm, Peter; Josephson, Malin; Mathiassen, Svend Erik; Kjellberg, Katarina

    2016-06-01

    We evaluated the intra- and inter-observer reliability and criterion validity of an observation protocol, developed in an iterative process involving practicing ergonomists, for assessment of working technique during cash register work for the purpose of preventing upper extremity symptoms. Two ergonomists independently assessed 17 15-min videos of cash register work on two occasions each, as a basis for examining reliability. Criterion validity was assessed by comparing these assessments with meticulous video-based analyses by researchers. Intra-observer reliability was acceptable (i.e. proportional agreement >0.7 and kappa >0.4) for 10/10 questions. Inter-observer reliability was acceptable for only 3/10 questions. An acceptable inter-observer reliability combined with an acceptable criterion validity was obtained only for one working technique aspect, 'Quality of movements'. Thus, major elements of the cashiers' working technique could not be assessed with an acceptable accuracy from short periods of observations by one observer, such as often desired by practitioners. Practitioner Summary: We examined an observation protocol for assessing working technique in cash register work. It was feasible in use, but inter-observer reliability and criterion validity were generally not acceptable when working technique aspects were assessed from short periods of work. We recommend the protocol to be used for educational purposes only.

  4. Proteomic Challenges: Sample Preparation Techniques for Microgram-Quantity Protein Analysis from Biological Samples

    Science.gov (United States)

    Feist, Peter; Hummon, Amanda B.

    2015-01-01

    Proteins regulate many cellular functions and analyzing the presence and abundance of proteins in biological samples are central focuses in proteomics. The discovery and validation of biomarkers, pathways, and drug targets for various diseases can be accomplished using mass spectrometry-based proteomics. However, with mass-limited samples like tumor biopsies, it can be challenging to obtain sufficient amounts of proteins to generate high-quality mass spectrometric data. Techniques developed for macroscale quantities recover sufficient amounts of protein from milligram quantities of starting material, but sample losses become crippling with these techniques when only microgram amounts of material are available. To combat this challenge, proteomicists have developed micro-scale techniques that are compatible with decreased sample size (100 μg or lower) and still enable excellent proteome coverage. Extraction, contaminant removal, protein quantitation, and sample handling techniques for the microgram protein range are reviewed here, with an emphasis on liquid chromatography and bottom-up mass spectrometry-compatible techniques. Also, a range of biological specimens, including mammalian tissues and model cell culture systems, are discussed. PMID:25664860

  5. Proteomic challenges: sample preparation techniques for microgram-quantity protein analysis from biological samples.

    Science.gov (United States)

    Feist, Peter; Hummon, Amanda B

    2015-02-05

    Proteins regulate many cellular functions and analyzing the presence and abundance of proteins in biological samples are central focuses in proteomics. The discovery and validation of biomarkers, pathways, and drug targets for various diseases can be accomplished using mass spectrometry-based proteomics. However, with mass-limited samples like tumor biopsies, it can be challenging to obtain sufficient amounts of proteins to generate high-quality mass spectrometric data. Techniques developed for macroscale quantities recover sufficient amounts of protein from milligram quantities of starting material, but sample losses become crippling with these techniques when only microgram amounts of material are available. To combat this challenge, proteomicists have developed micro-scale techniques that are compatible with decreased sample size (100 μg or lower) and still enable excellent proteome coverage. Extraction, contaminant removal, protein quantitation, and sample handling techniques for the microgram protein range are reviewed here, with an emphasis on liquid chromatography and bottom-up mass spectrometry-compatible techniques. Also, a range of biological specimens, including mammalian tissues and model cell culture systems, are discussed.

  6. Proteomic Challenges: Sample Preparation Techniques for Microgram-Quantity Protein Analysis from Biological Samples

    Directory of Open Access Journals (Sweden)

    Peter Feist

    2015-02-01

    Full Text Available Proteins regulate many cellular functions and analyzing the presence and abundance of proteins in biological samples are central focuses in proteomics. The discovery and validation of biomarkers, pathways, and drug targets for various diseases can be accomplished using mass spectrometry-based proteomics. However, with mass-limited samples like tumor biopsies, it can be challenging to obtain sufficient amounts of proteins to generate high-quality mass spectrometric data. Techniques developed for macroscale quantities recover sufficient amounts of protein from milligram quantities of starting material, but sample losses become crippling with these techniques when only microgram amounts of material are available. To combat this challenge, proteomicists have developed micro-scale techniques that are compatible with decreased sample size (100 μg or lower and still enable excellent proteome coverage. Extraction, contaminant removal, protein quantitation, and sample handling techniques for the microgram protein range are reviewed here, with an emphasis on liquid chromatography and bottom-up mass spectrometry-compatible techniques. Also, a range of biological specimens, including mammalian tissues and model cell culture systems, are discussed.

  7. Development of environmental sample analysis techniques for safeguards

    International Nuclear Information System (INIS)

    Magara, Masaaki; Hanzawa, Yukiko; Esaka, Fumitaka

    1999-01-01

    JAERI has been developing environmental sample analysis techniques for safeguards and preparing a clean chemistry laboratory with clean rooms. Methods to be developed are a bulk analysis and a particle analysis. In the bulk analysis, Inductively-Coupled Plasma Mass Spectrometer or Thermal Ionization Mass Spectrometer are used to measure nuclear materials after chemical treatment of sample. In the particle analysis, Electron Probe Micro Analyzer and Secondary Ion Mass Spectrometer are used for elemental analysis and isotopic analysis, respectively. The design of the clean chemistry laboratory has been carried out and construction will be completed by the end of March, 2001. (author)

  8. Refinement of NMR structures using implicit solvent and advanced sampling techniques.

    Science.gov (United States)

    Chen, Jianhan; Im, Wonpil; Brooks, Charles L

    2004-12-15

    NMR biomolecular structure calculations exploit simulated annealing methods for conformational sampling and require a relatively high level of redundancy in the experimental restraints to determine quality three-dimensional structures. Recent advances in generalized Born (GB) implicit solvent models should make it possible to combine information from both experimental measurements and accurate empirical force fields to improve the quality of NMR-derived structures. In this paper, we study the influence of implicit solvent on the refinement of protein NMR structures and identify an optimal protocol of utilizing these improved force fields. To do so, we carry out structure refinement experiments for model proteins with published NMR structures using full NMR restraints and subsets of them. We also investigate the application of advanced sampling techniques to NMR structure refinement. Similar to the observations of Xia et al. (J.Biomol. NMR 2002, 22, 317-331), we find that the impact of implicit solvent is rather small when there is a sufficient number of experimental restraints (such as in the final stage of NMR structure determination), whether implicit solvent is used throughout the calculation or only in the final refinement step. The application of advanced sampling techniques also seems to have minimal impact in this case. However, when the experimental data are limited, we demonstrate that refinement with implicit solvent can substantially improve the quality of the structures. In particular, when combined with an advanced sampling technique, the replica exchange (REX) method, near-native structures can be rapidly moved toward the native basin. The REX method provides both enhanced sampling and automatic selection of the most native-like (lowest energy) structures. An optimal protocol based on our studies first generates an ensemble of initial structures that maximally satisfy the available experimental data with conventional NMR software using a simplified

  9. Nuclear analytical techniques and their application to environmental samples

    International Nuclear Information System (INIS)

    Lieser, K.H.

    1986-01-01

    A survey is given on nuclear analytical techniques and their application to environmental samples. Measurement of the inherent radioactivity of elements or radionuclides allows determination of natural radioelements (e.g. Ra), man-made radioelements (e.g. Pu) and radionuclides in the environment. Activation analysis, in particular instrumental neutron activation analysis, is a very reliable and sensitive method for determination of a great number of trace elements in environmental samples, because the most abundant main constituents are not activated. Tracer techniques are very useful for studies of the behaviour and of chemical reactions of trace elements and compounds in the environment. Radioactive sources are mainly applied for excitation of characteristic X-rays (X-ray fluorescence analysis). (author)

  10. The perils of straying from protocol: sampling bias and interviewer effects.

    Directory of Open Access Journals (Sweden)

    Carrie J Ngongo

    Full Text Available Fidelity to research protocol is critical. In a contingent valuation study in an informal urban settlement in Nairobi, Kenya, participants responded differently to the three trained interviewers. Interviewer effects were present during the survey pilot, then magnified at the start of the main survey after a seemingly slight adaptation of the survey sampling protocol allowed interviewers to speak with the "closest neighbor" in the event that no one was home at a selected household. This slight degree of interviewer choice led to inferred sampling bias. Multinomial logistic regression and post-estimation tests revealed that the three interviewers' samples differed significantly from one another according to six demographic characteristics. The two female interviewers were 2.8 and 7.7 times less likely to talk with respondents of low socio-economic status than the male interviewer. Systematic error renders it impossible to determine which of the survey responses might be "correct." This experience demonstrates why researchers must take care to strictly follow sampling protocols, consistently train interviewers, and monitor responses by interview to ensure similarity between interviewers' groups and produce unbiased estimates of the parameters of interest.

  11. Robowell: An automated process for monitoring ground water quality using established sampling protocols

    Science.gov (United States)

    Granato, G.E.; Smith, K.P.

    1999-01-01

    Robowell is an automated process for monitoring selected ground water quality properties and constituents by pumping a well or multilevel sampler. Robowell was developed and tested to provide a cost-effective monitoring system that meets protocols expected for manual sampling. The process uses commercially available electronics, instrumentation, and hardware, so it can be configured to monitor ground water quality using the equipment, purge protocol, and monitoring well design most appropriate for the monitoring site and the contaminants of interest. A Robowell prototype was installed on a sewage treatment plant infiltration bed that overlies a well-studied unconfined sand and gravel aquifer at the Massachusetts Military Reservation, Cape Cod, Massachusetts, during a time when two distinct plumes of constituents were released. The prototype was operated from May 10 to November 13, 1996, and quality-assurance/quality-control measurements demonstrated that the data obtained by the automated method was equivalent to data obtained by manual sampling methods using the same sampling protocols. Water level, specific conductance, pH, water temperature, dissolved oxygen, and dissolved ammonium were monitored by the prototype as the wells were purged according to U.S Geological Survey (USGS) ground water sampling protocols. Remote access to the data record, via phone modem communications, indicated the arrival of each plume over a few days and the subsequent geochemical reactions over the following weeks. Real-time availability of the monitoring record provided the information needed to initiate manual sampling efforts in response to changes in measured ground water quality, which proved the method and characterized the screened portion of the plume in detail through time. The methods and the case study described are presented to document the process for future use.

  12. Improved mesh based photon sampling techniques for neutron activation analysis

    International Nuclear Information System (INIS)

    Relson, E.; Wilson, P. P. H.; Biondo, E. D.

    2013-01-01

    The design of fusion power systems requires analysis of neutron activation of large, complex volumes, and the resulting particles emitted from these volumes. Structured mesh-based discretization of these problems allows for improved modeling in these activation analysis problems. Finer discretization of these problems results in large computational costs, which drives the investigation of more efficient methods. Within an ad hoc subroutine of the Monte Carlo transport code MCNP, we implement sampling of voxels and photon energies for volumetric sources using the alias method. The alias method enables efficient sampling of a discrete probability distribution, and operates in 0(1) time, whereas the simpler direct discrete method requires 0(log(n)) time. By using the alias method, voxel sampling becomes a viable alternative to sampling space with the 0(1) approach of uniformly sampling the problem volume. Additionally, with voxel sampling it is straightforward to introduce biasing of volumetric sources, and we implement this biasing of voxels as an additional variance reduction technique that can be applied. We verify our implementation and compare the alias method, with and without biasing, to direct discrete sampling of voxels, and to uniform sampling. We study the behavior of source biasing in a second set of tests and find trends between improvements and source shape, material, and material density. Overall, however, the magnitude of improvements from source biasing appears to be limited. Future work will benefit from the implementation of efficient voxel sampling - particularly with conformal unstructured meshes where the uniform sampling approach cannot be applied. (authors)

  13. Results of a protocol of transfusion threshold and surgical technique on transfusion requirements in burn patients.

    Science.gov (United States)

    O'Mara, Michael S; Hayetian, Fernando; Slater, Harvey; Goldfarb, I William; Tolchin, Eric; Caushaj, Philip F

    2005-08-01

    Blood loss and high rates of transfusion in burn centers remains an area of ongoing concern. Blood use brings the risk of infection, adverse reaction, and immunosuppression. A protocol to reduce blood loss and blood use was implemented. Analysis included 3-year periods before and after institution of the protocol. All patients were transfused for a hemoglobin below 8.0 gm/dL. Operations per admission did not change during the two time periods (0.78 in each). Overall units transfused per operation decreased from 1.56+/-0.06 to 1.25+/-0.14 units after instituting the protocol (pburns of less than 20% surface area, declining from 386 to 46 units after protocol institution, from 0.37 to 0.04 units per admission, and from 0.79 to 0.08 units per operation in this group of smallest burns. There was no change noted in the larger burns. This study suggests that a defined protocol of hemostasis, technique, and transfusion trigger should be implemented in the process of burn excision and grafting. This will help especially those patients with the smallest burns, essentially eliminating transfusion need in that group.

  14. A Comparison of Soil-Water Sampling Techniques

    Science.gov (United States)

    Tindall, J. A.; Figueroa-Johnson, M.; Friedel, M. J.

    2007-12-01

    The representativeness of soil pore water extracted by suction lysimeters in ground-water monitoring studies is a problem that often confounds interpretation of measured data. Current soil water sampling techniques cannot identify the soil volume from which a pore water sample is extracted, neither macroscopic, microscopic, or preferential flowpath. This research was undertaken to compare values of extracted suction lysimeters samples from intact soil cores with samples obtained by the direct extraction methods to determine what portion of soil pore water is sampled by each method. Intact soil cores (30 centimeter (cm) diameter by 40 cm height) were extracted from two different sites - a sandy soil near Altamonte Springs, Florida and a clayey soil near Centralia in Boone County, Missouri. Isotopically labeled water (O18? - analyzed by mass spectrometry) and bromide concentrations (KBr- - measured using ion chromatography) from water samples taken by suction lysimeters was compared with samples obtained by direct extraction methods of centrifugation and azeotropic distillation. Water samples collected by direct extraction were about 0.25 ? more negative (depleted) than that collected by suction lysimeter values from a sandy soil and about 2-7 ? more negative from a well structured clayey soil. Results indicate that the majority of soil water in well-structured soil is strongly bound to soil grain surfaces and is not easily sampled by suction lysimeters. In cases where a sufficient volume of water has passed through the soil profile and displaced previous pore water, suction lysimeters will collect a representative sample of soil pore water from the sampled depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeter should be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The data also indicate that each extraction method be use to sample a different

  15. Comparison of correlation analysis techniques for irregularly sampled time series

    Directory of Open Access Journals (Sweden)

    K. Rehfeld

    2011-06-01

    Full Text Available Geoscientific measurements often provide time series with irregular time sampling, requiring either data reconstruction (interpolation or sophisticated methods to handle irregular sampling. We compare the linear interpolation technique and different approaches for analyzing the correlation functions and persistence of irregularly sampled time series, as Lomb-Scargle Fourier transformation and kernel-based methods. In a thorough benchmark test we investigate the performance of these techniques.

    All methods have comparable root mean square errors (RMSEs for low skewness of the inter-observation time distribution. For high skewness, very irregular data, interpolation bias and RMSE increase strongly. We find a 40 % lower RMSE for the lag-1 autocorrelation function (ACF for the Gaussian kernel method vs. the linear interpolation scheme,in the analysis of highly irregular time series. For the cross correlation function (CCF the RMSE is then lower by 60 %. The application of the Lomb-Scargle technique gave results comparable to the kernel methods for the univariate, but poorer results in the bivariate case. Especially the high-frequency components of the signal, where classical methods show a strong bias in ACF and CCF magnitude, are preserved when using the kernel methods.

    We illustrate the performances of interpolation vs. Gaussian kernel method by applying both to paleo-data from four locations, reflecting late Holocene Asian monsoon variability as derived from speleothem δ18O measurements. Cross correlation results are similar for both methods, which we attribute to the long time scales of the common variability. The persistence time (memory is strongly overestimated when using the standard, interpolation-based, approach. Hence, the Gaussian kernel is a reliable and more robust estimator with significant advantages compared to other techniques and suitable for large scale application to paleo-data.

  16. Development of a protocol for sampling and analysis of ballast water in Jamaica

    Directory of Open Access Journals (Sweden)

    Achsah A Mitchell

    2014-09-01

    Full Text Available The transfer of ballast by the international shipping industry has negatively impacted the environment. To design such a protocol for the area, the ballast water tanks of seven bulk cargo vessels entering a Jamaican port were sampled between January 28, 2010 and August 17, 2010. Vessels originated from five ports and used three main routes, some of which conducted ballast water exchange. Twenty-six preserved and 22 live replicate zooplankton samples were obtained. Abundance and richness were higher than at temperate ports. Exchange did not alter the biotic composition but reduced the abundance. Two of the live sample replicates, containing 31.67 and 16.75 viable individuals m-3, were non-compliant with the International Convention for the Control and Management of Ships’ Ballast Water and Sediments. Approximately 12% of the species identified in the ballast water were present in the waters nearest the port in 1995 and 11% were present in the entire bay in 2005. The protocol designed from this study can be used to aid the establishment of a ballast water management system in the Caribbean or used as a foundation for the development of further protocols.

  17. Protocols for the analytical characterization of therapeutic monoclonal antibodies. II - Enzymatic and chemical sample preparation.

    Science.gov (United States)

    Bobaly, Balazs; D'Atri, Valentina; Goyon, Alexandre; Colas, Olivier; Beck, Alain; Fekete, Szabolcs; Guillarme, Davy

    2017-08-15

    The analytical characterization of therapeutic monoclonal antibodies and related proteins usually incorporates various sample preparation methodologies. Indeed, quantitative and qualitative information can be enhanced by simplifying the sample, thanks to the removal of sources of heterogeneity (e.g. N-glycans) and/or by decreasing the molecular size of the tested protein by enzymatic or chemical fragmentation. These approaches make the sample more suitable for chromatographic and mass spectrometric analysis. Structural elucidation and quality control (QC) analysis of biopharmaceutics are usually performed at intact, subunit and peptide levels. In this paper, general sample preparation approaches used to attain peptide, subunit and glycan level analysis are overviewed. Protocols are described to perform tryptic proteolysis, IdeS and papain digestion, reduction as well as deglycosylation by PNGase F and EndoS2 enzymes. Both historical and modern sample preparation methods were compared and evaluated using rituximab and trastuzumab, two reference therapeutic mAb products approved by Food and Drug Administration (FDA) and European Medicines Agency (EMA). The described protocols may help analysts to develop sample preparation methods in the field of therapeutic protein analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Zoonoses action plan Salmonella monitoring programme: an investigation of the sampling protocol.

    Science.gov (United States)

    Snary, E L; Munday, D K; Arnold, M E; Cook, A J C

    2010-03-01

    The Zoonoses Action Plan (ZAP) Salmonella Programme was established by the British Pig Executive to monitor Salmonella prevalence in quality-assured British pigs at slaughter by testing a sample of pigs with a meat juice enzyme-linked immunosorbent assay for antibodies against group B and C(1) Salmonella. Farms were assigned a ZAP level (1 to 3) depending on the monitored prevalence, and ZAP 2 or 3 farms were required to act to reduce the prevalence. The ultimate goal was to reduce the risk of human salmonellosis attributable to British pork. A mathematical model has been developed to describe the ZAP sampling protocol. Results show that the probability of assigning a farm the correct ZAP level was high, except for farms that had a seroprevalence close to the cutoff points between different ZAP levels. Sensitivity analyses identified that the probability of assigning a farm to the correct ZAP level was dependent on the sensitivity and specificity of the test, the number of batches taken to slaughter each quarter, and the number of samples taken per batch. The variability of the predicted seroprevalence was reduced as the number of batches or samples increased and, away from the cutoff points, the probability of being assigned the correct ZAP level increased as the number of batches or samples increased. In summary, the model described here provided invaluable insight into the ZAP sampling protocol. Further work is required to understand the impact of the program for Salmonella infection in British pig farms and therefore on human health.

  19. An optimized protocol for handling and processing fragile acini cultured with the hanging drop technique.

    Science.gov (United States)

    Snyman, Celia; Elliott, Edith

    2011-12-15

    The hanging drop three-dimensional culture technique allows cultivation of functional three-dimensional mammary constructs without exogenous extracellular matrix. The fragile acini are, however, difficult to preserve during processing steps for advanced microscopic investigation. We describe adaptations to the protocol for handling of hanging drop cultures to include investigation using confocal, scanning, and electron microscopy, with minimal loss of cell culture components. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Separation Techniques for Quantification of Radionuclides in Environmental Samples

    Directory of Open Access Journals (Sweden)

    Dusan Galanda

    2009-01-01

    Full Text Available The reliable and quantitative measurement of radionuclides is important in order to determine environmental quality and radiation safety, and to monitor regulatory compliance. We examined soil samples from Podunajske Biskupice, near the city of Bratislava in the Slovak Republic, for the presence of several natural (238U, 232Th, 40K and anthropogenic (137Cs, 90Sr, 239Pu, 240Pu, 241Am radionuclides. The area is adjacent to a refinery and hazardous waste processing center, as well as the municipal incinerator plant, and so might possess an unusually high level of ecotoxic metals. We found that the levels of both naturally occurring and anthropogenic radionuclides fell within the expected ranges, indicating that these facilities pose no radiological threat to the local environment. During the course of our analysis, we modified existing techniques in order to allow us to handle the unusually large and complex samples that were needed to determine the levels of 239Pu, 240Pu, and 241Am activity. We also rated three commercial techniques for the separation of 90Sr from aqueous solutions and found that two of them, AnaLig Sr-01 and Empore Extraction Disks, were suitable for the quantitative and reliable separation of 90Sr, while the third, Sr-Spec Resin, was less so. The main criterion in evaluating these methods was the chemical recovery of 90Sr, which was less than we had expected. We also considered speed of separation and additional steps needed to prepare the sample for separation.

  1. Nonactivation interaction techniques in the analysis of environmental samples

    International Nuclear Information System (INIS)

    Tolgyessy, J.

    1986-01-01

    Nonactivation interaction analytical methods are based on the interaction processes of nuclear and X-ray radiation with a sample, leading to their absorption and backscattering, to the ionization of gases or excitation of fluorescent X-ray by radiation, but not to the activation of determined elements. From the point of view of environmental analysis, the most useful nonactivation interaction techniques are X-ray fluorescence by photon or charged particle excitation, ionization of gases by nuclear radiation, elastic scattering of charged particles and backscattering of beta radiation. The significant advantage of these methods is that they are nondestructive. (author)

  2. Development of a new protocol for rapid bacterial identification and susceptibility testing directly from urine samples.

    Science.gov (United States)

    Zboromyrska, Y; Rubio, E; Alejo, I; Vergara, A; Mons, A; Campo, I; Bosch, J; Marco, F; Vila, J

    2016-06-01

    The current gold standard method for the diagnosis of urinary tract infections (UTI) is urine culture that requires 18-48 h for the identification of the causative microorganisms and an additional 24 h until the results of antimicrobial susceptibility testing (AST) are available. The aim of this study was to shorten the time of urine sample processing by a combination of flow cytometry for screening and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for bacterial identification followed by AST directly from urine. The study was divided into two parts. During the first part, 675 urine samples were processed by a flow cytometry device and a cut-off value of bacterial count was determined to select samples for direct identification by MALDI-TOF-MS at ≥5 × 10(6) bacteria/mL. During the second part, 163 of 1029 processed samples reached the cut-off value. The sample preparation protocol for direct identification included two centrifugation and two washing steps. Direct AST was performed by the disc diffusion method if a reliable direct identification was obtained. Direct MALDI-TOF-MS identification was performed in 140 urine samples; 125 of the samples were positive by urine culture, 12 were contaminated and 3 were negative. Reliable direct identification was obtained in 108 (86.4%) of the 125 positive samples. AST was performed in 102 identified samples, and the results were fully concordant with the routine method among 83 monomicrobial infections. In conclusion, the turnaround time of the protocol described to diagnose UTI was about 1 h for microbial identification and 18-24 h for AST. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  3. MPLEx: a Robust and Universal Protocol for Single-Sample Integrative Proteomic, Metabolomic, and Lipidomic Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Nakayasu, Ernesto S.; Nicora, Carrie D.; Sims, Amy C.; Burnum-Johnson, Kristin E.; Kim, Young-Mo; Kyle, Jennifer E.; Matzke, Melissa M.; Shukla, Anil K.; Chu, Rosalie K.; Schepmoes, Athena A.; Jacobs, Jon M.; Baric, Ralph S.; Webb-Robertson, Bobbie-Jo; Smith, Richard D.; Metz, Thomas O.; Chia, Nicholas

    2016-05-03

    ABSTRACT

    Integrative multi-omics analyses can empower more effective investigation and complete understanding of complex biological systems. Despite recent advances in a range of omics analyses, multi-omic measurements of the same sample are still challenging and current methods have not been well evaluated in terms of reproducibility and broad applicability. Here we adapted a solvent-based method, widely applied for extracting lipids and metabolites, to add proteomics to mass spectrometry-based multi-omics measurements. Themetabolite,protein, andlipidextraction (MPLEx) protocol proved to be robust and applicable to a diverse set of sample types, including cell cultures, microbial communities, and tissues. To illustrate the utility of this protocol, an integrative multi-omics analysis was performed using a lung epithelial cell line infected with Middle East respiratory syndrome coronavirus, which showed the impact of this virus on the host glycolytic pathway and also suggested a role for lipids during infection. The MPLEx method is a simple, fast, and robust protocol that can be applied for integrative multi-omic measurements from diverse sample types (e.g., environmental,in vitro, and clinical).

    IMPORTANCEIn systems biology studies, the integration of multiple omics measurements (i.e., genomics, transcriptomics, proteomics, metabolomics, and lipidomics) has been shown to provide a more complete and informative view of biological pathways. Thus, the prospect of extracting different types of molecules (e.g., DNAs, RNAs, proteins, and metabolites) and performing multiple omics measurements on single samples is very attractive, but such studies are challenging due to the fact that the extraction conditions differ according to the molecule type. Here, we adapted an organic solvent-based extraction method that demonstrated

  4. Waste minimization in analytical chemistry through innovative sample preparation techniques

    International Nuclear Information System (INIS)

    Smith, L. L.

    1998-01-01

    water samples. In this SPME technique, a fused-silica fiber coated with a polymeric film is exposed to the sample, extraction is allowed to take place, and then the analytes are thermally desorbed for GC analysis. Unlike liquid-liquid extraction or solid-phase extraction, SPME consumes all of the extracted sample in the analysis, significantly reducing the required sample volume

  5. Stratified source-sampling techniques for Monte Carlo eigenvalue analysis

    International Nuclear Information System (INIS)

    Mohamed, A.

    1998-01-01

    In 1995, at a conference on criticality safety, a special session was devoted to the Monte Carlo ''Eigenvalue of the World'' problem. Argonne presented a paper, at that session, in which the anomalies originally observed in that problem were reproduced in a much simplified model-problem configuration, and removed by a version of stratified source-sampling. In this paper, stratified source-sampling techniques are generalized and applied to three different Eigenvalue of the World configurations which take into account real-world statistical noise sources not included in the model problem, but which differ in the amount of neutronic coupling among the constituents of each configuration. It is concluded that, in Monte Carlo eigenvalue analysis of loosely-coupled arrays, the use of stratified source-sampling reduces the probability of encountering an anomalous result over that if conventional source-sampling methods are used. However, this gain in reliability is substantially less than that observed in the model-problem results

  6. Active SAmpling Protocol (ASAP) to Optimize Individual Neurocognitive Hypothesis Testing: A BCI-Inspired Dynamic Experimental Design.

    Science.gov (United States)

    Sanchez, Gaëtan; Lecaignard, Françoise; Otman, Anatole; Maby, Emmanuel; Mattout, Jérémie

    2016-01-01

    The relatively young field of Brain-Computer Interfaces has promoted the use of electrophysiology and neuroimaging in real-time. In the meantime, cognitive neuroscience studies, which make extensive use of functional exploration techniques, have evolved toward model-based experiments and fine hypothesis testing protocols. Although these two developments are mostly unrelated, we argue that, brought together, they may trigger an important shift in the way experimental paradigms are being designed, which should prove fruitful to both endeavors. This change simply consists in using real-time neuroimaging in order to optimize advanced neurocognitive hypothesis testing. We refer to this new approach as the instantiation of an Active SAmpling Protocol (ASAP). As opposed to classical (static) experimental protocols, ASAP implements online model comparison, enabling the optimization of design parameters (e.g., stimuli) during the course of data acquisition. This follows the well-known principle of sequential hypothesis testing. What is radically new, however, is our ability to perform online processing of the huge amount of complex data that brain imaging techniques provide. This is all the more relevant at a time when physiological and psychological processes are beginning to be approached using more realistic, generative models which may be difficult to tease apart empirically. Based upon Bayesian inference, ASAP proposes a generic and principled way to optimize experimental design adaptively. In this perspective paper, we summarize the main steps in ASAP. Using synthetic data we illustrate its superiority in selecting the right perceptual model compared to a classical design. Finally, we briefly discuss its future potential for basic and clinical neuroscience as well as some remaining challenges.

  7. Identification of unknown sample using NAA, EDXRF, XRD techniques

    International Nuclear Information System (INIS)

    Dalvi, Aditi A.; Swain, K.K.; Chavan, Trupti; Remya Devi, P.S.; Wagh, D.N.; Verma, R.

    2015-01-01

    Analytical Chemistry Division (ACD), Bhabha Atomic Research Centre (BARC) receives samples from law enforcement agencies such as Directorate of Revenue Intelligence, Customs for analysis. Five unknown grey powdered samples were received for identification and were suspected to be Iridium (Ir). Identification of unknown sample is always a challenging task and suitable analytical techniques have to be judiciously utilized for arriving at the conclusion. Qualitative analysis was carried out using Jordan Valley, EX-3600 M Energy dispersive X-ray fluorescence (EDXRF) spectrometer at ACD, BARC. A SLP series LEO Si (Li) detector (active area: 30 mm 2 ; thickness: 3.5 mm; resolution: 140 eV at 5.9 keV of Mn K X-ray) was used during the measurement and only characteristic X-rays of Ir (Lα: 9.17 keV and Lβ: 10.70 keV) was seen in the X-ray spectrum. X-ray diffraction (XRD) measurement results indicated that the Ir was in the form of metal. To confirm the XRD data, neutron activation analysis (NAA) was carried out by irradiating samples and elemental standards (as comparator) in graphite reflector position of Advanced Heavy Water Reactor Critical Facility (AHWR CF) reactor, BARC, Mumbai. After suitable decay period, gamma activity measurements were carried out using 45% HPGe detector coupled to 8 k multi channel analyzer. Characteristic gamma line at 328.4 keV of the activation product 194 Ir was used for quantification of iridium and relative method of NAA was used for concentration calculations. NAA results confirmed that all the samples were Iridium metal. (author)

  8. New protocol for construction of eyeglasses-supported provisional nasal prosthesis using CAD/CAM techniques.

    Science.gov (United States)

    Ciocca, Leonardo; Fantini, Massimiliano; De Crescenzio, Francesca; Persiani, Franco; Scotti, Roberto

    2010-01-01

    A new protocol for making an immediate provisional eyeglasses-supported nasal prosthesis is presented that uses laser scanning, computer-aided design/computer-aided manufacturing procedures, and rapid prototyping techniques, reducing time and costs while increasing the quality of the final product. With this protocol, the eyeglasses were digitized, and the relative position of the nasal prosthesis was planned and evaluated in a virtual environment without any try-in appointment. This innovative method saves time, reduces costs, and restores the patient's aesthetic appearance after a disfiguration caused by ablation of the nasal pyramid better than conventional restoration methods. Moreover, the digital model of the designed nasal epithesis can be used to develop a definitive prosthesis anchored to osseointegrated craniofacial implants.

  9. Discrepancies in sample size calculations and data analyses reported in randomised trials: comparison of publications with protocols

    DEFF Research Database (Denmark)

    Chan, A.W.; Hrobjartsson, A.; Jorgensen, K.J.

    2008-01-01

    OBJECTIVE: To evaluate how often sample size calculations and methods of statistical analysis are pre-specified or changed in randomised trials. DESIGN: Retrospective cohort study. Data source Protocols and journal publications of published randomised parallel group trials initially approved...... in 1994-5 by the scientific-ethics committees for Copenhagen and Frederiksberg, Denmark (n=70). MAIN OUTCOME MEASURE: Proportion of protocols and publications that did not provide key information about sample size calculations and statistical methods; proportion of trials with discrepancies between...... of handling missing data was described in 16 protocols and 49 publications. 39/49 protocols and 42/43 publications reported the statistical test used to analyse primary outcome measures. Unacknowledged discrepancies between protocols and publications were found for sample size calculations (18/34 trials...

  10. Elemental analysis of brazing alloy samples by neutron activation technique

    International Nuclear Information System (INIS)

    Eissa, E.A.; Rofail, N.B.; Hassan, A.M.; El-Shershaby, A.; Walley El-Dine, N.

    1996-01-01

    Two brazing alloy samples (C P 2 and C P 3 ) have been investigated by Neutron activation analysis (NAA) technique in order to identify and estimate their constituent elements. The pneumatic irradiation rabbit system (PIRS), installed at the first egyptian research reactor (ETRR-1) was used for short-time irradiation (30 s) with a thermal neutron flux of 1.6 x 10 1 1 n/cm 2 /s in the reactor reflector, where the thermal to epithermal neutron flux ratio is 106. Long-time irradiation (48 hours) was performed at reactor core periphery with thermal neutron flux of 3.34 x 10 1 2 n/cm 2 /s, and thermal to epithermal neutron flux ratio of 79. Activation by epithermal neutrons was taken into account for the (1/v) and resonance neutron absorption in both methods. A hyper pure germanium detection system was used for gamma-ray acquisitions. The concentration values of Al, Cr, Fe, Co, Cu, Zn, Se, Ag and Sb were estimated as percentages of the sample weight and compared with reported values. 1 tab

  11. Analysis of soil samples from Gebeng area using NAA technique

    Science.gov (United States)

    Elias, Md Suhaimi; Wo, Yii Mei; Hamzah, Mohd Suhaimi; Shukor, Shakirah Abd; Rahman, Shamsiah Ab; Salim, Nazaratul Ashifa Abdullah; Azman, Muhamad Azfar; Hashim, Azian

    2017-01-01

    Rapid development and urbanization will increase number of residence and industrial area. Without proper management and control of pollution, these will give an adverse effect to environment and human life. The objective of this study to identify and quantify key contaminants into the environment of the Gebeng area as a result of industrial and human activities. Gebeng area was gazetted as one of the industrial estate in Pahang state. Assessment of elemental pollution in soil of Gebeng area base on level of concentration, enrichment factor and geo-accumulation index. The enrichment factors (EFs) were determined by the elemental rationing method, whilst the geo-accumulation index (Igeo) by comparing of current to continental crustal average concentration of element. Twenty-seven of soil samples were collected from Gebeng area. Soil samples were analysed by using Neutron Activation Analyses (NAA) technique. The obtained data showed higher concentration of iron (Fe) due to abundance in soil compared to other elements. The results of enrichment factor showed that Gebeng area have enrich with elements of As, Br, Hf, Sb, Th and U. Base on the geo-accumulation index (Igeo) classification, the soil quality of Gebeng area can be classified as class 0, (uncontaminated) to Class 3, (moderately to heavily contaminated).

  12. Elemental analysis of brazing alloy samples by neutron activation technique

    Energy Technology Data Exchange (ETDEWEB)

    Eissa, E A; Rofail, N B; Hassan, A M [Reactor and Neutron physics Department, Nuclear Research Centre, Atomic Energy Authority, Cairo (Egypt); El-Shershaby, A; Walley El-Dine, N [Physics Department, Faculty of Girls, Ain Shams Universty, Cairo (Egypt)

    1997-12-31

    Two brazing alloy samples (C P{sup 2} and C P{sup 3}) have been investigated by Neutron activation analysis (NAA) technique in order to identify and estimate their constituent elements. The pneumatic irradiation rabbit system (PIRS), installed at the first egyptian research reactor (ETRR-1) was used for short-time irradiation (30 s) with a thermal neutron flux of 1.6 x 10{sup 1}1 n/cm{sup 2}/s in the reactor reflector, where the thermal to epithermal neutron flux ratio is 106. Long-time irradiation (48 hours) was performed at reactor core periphery with thermal neutron flux of 3.34 x 10{sup 1}2 n/cm{sup 2}/s, and thermal to epithermal neutron flux ratio of 79. Activation by epithermal neutrons was taken into account for the (1/v) and resonance neutron absorption in both methods. A hyper pure germanium detection system was used for gamma-ray acquisitions. The concentration values of Al, Cr, Fe, Co, Cu, Zn, Se, Ag and Sb were estimated as percentages of the sample weight and compared with reported values. 1 tab.

  13. Active sampling technique to enhance chemical signature of buried explosives

    Science.gov (United States)

    Lovell, John S.; French, Patrick D.

    2004-09-01

    Deminers and dismounted countermine engineers commonly use metal detectors, ground penetrating radar and probes to locate mines. Many modern landmines have a very low metal content, which severely limits the effectiveness of metal detectors. Canines have also been used for landmine detection for decades. Experiments have shown that canines smell the explosives which are known to leak from most types of landmines. The fact that dogs can detect landmines indicates that vapor sensing is a viable approach to landmine detection. Several groups are currently developing systems to detect landmines by "sniffing" for the ultra-trace explosive vapors above the soil. The amount of material that is available to passive vapor sensing systems is limited to no more than the vapor in equilibrium with the explosive related chemicals (ERCs) distributed in the surface soils over and near the landmine. The low equilibrium vapor pressure of TNT in the soil/atmosphere boundary layer and the limited volume of the boundary layer air imply that passive chemical vapor sensing systems require sensitivities in the picogram range, or lower. ADA is working to overcome many of the limitations of passive sampling methods, by the use of an active sampling method that employs a high-powered (1,200+ joules) strobe lamp to create a highly amplified plume of vapor and/or ERC-bearing fine particulates. Initial investigations have demonstrated that this approach can amplify the detectability of TNT by two or three orders of magnitude. This new active sampling technique could be used with any suitable explosive sensor.

  14. Novel Techniques with the Aid of a Staged CBCT Guided Surgical Protocol

    Directory of Open Access Journals (Sweden)

    Evdokia Chasioti

    2015-01-01

    Full Text Available The case report will present some novel techniques for using a “staged” protocol utilizing strategic periodontally involved teeth as transitional abutments in combination with CBCT guided implant surgery. Staging the case prevented premature loading of the grafted sites during the healing phase. A CBCT following a tenting screw guided bone regeneration procedure ensured adequate bone to place an implant fixture. Proper assessment of the CBCT allowed the surgeon to do an osteotome internal sinus lift in an optimum location. The depth of the bone needed for the osteotome sinus floor elevation was planned. The staged appliance allowed these sinus-augmented sites to heal for an extended period of time compared to implants, which were uncovered and loaded at an earlier time frame. The staged protocol and CBCT analysis enabled the immediate implants to be placed in proper alignment to the adjacent fixture. After teeth were extracted, the osseointegrated implants were converted to abutments for the transitional appliance. Finally, the staged protocol allowed for soft tissue enhancement in the implant and pontic areas prior to final insertion of the prosthesis.

  15. Development of analytical techniques for water and environmental samples (2)

    Energy Technology Data Exchange (ETDEWEB)

    Eum, Chul Hun; Jeon, Chi Wan; Jung, Kang Sup; Song, Kyung Sun; Kim, Sang Yeon [Korea Institute of Geology Mining and Materials, Taejon (Korea)

    1998-12-01

    The purpose of this study is to develop new analytical methods with good detection limit for toxic inorganic and organic compounds. The analyses of CN, organic acids, particulate materials in environmental samples have been done using several methods such as Ion Chromatography, SPE, SPME, GC/MS, GC/FID, SPLITT (split-flow thin cell fractionation) during the second year of this project. Advantage and disadvantage of several distillation method (by KS, JIS, EPA) for CN analysis in wastewater were investigated. As the results, we proposed new distillation apparatus for CN analysis, which was proved to be simpler, faster and to get better recovery than conventional apparatus. And ion chromatograph/pulsed amperometric detector (IC/PAD) system instead of colorimetry for CN detection was setup to solve matrix interference. And SPE(solid phase extraction) and SPME (solid phase micro extraction) as liquid-solid extraction technique were applied to the analysis of phenols in wastewater. Optimum experimental conditions and factors influencing analytical results were determined. From these results, It could be concluded that C{sub 18} cartridge and polystyrene-divinylbenzene disk in SPE method, polyacrylate fiber in SPME were proper solid phase adsorbent for phenol. Optimum conditions to analyze phenol derivatives simultaneously were established. Also, Continuous SPLITT (Split-flow thin cell) Fractionation (CSF) is a new preparative separation technique that is useful for fractionation of particulate and macromolecular materials. CSF is carried out in a thin ribbon-like channel equipped with two splitters at both inlet and outlet of the channel. In this work, we set up a new CSF system, and tested using polystyrene latex standard particles. And then we fractionated particles contained in air and underground water based on their sedimentation coefficients using CSF. (author). 27 refs., 13 tabs., 31 figs.

  16. Voltammetric technique, a panacea for analytical examination of environmental samples

    International Nuclear Information System (INIS)

    Zahir, E.; Mohiuddin, S.; Naqvi, I.I.

    2012-01-01

    Voltammetric methods for trace metal analysis in environmental samples of marine origin like mangrove, sediments and shrimps are generally recommended. Three different electro-analytical techniques i.e. polarography, anodic stripping voltammetry (ASV) and adsorptive stripping voltammetry (ADSV) have been used. Cd/sub 2/+, Pb/sub 2/+, Cu/sub 2/+ and Mn/sub 2/+ were determined through ASV, Cr/sub 6/+ was analyzed by ADSV and Fe/sub 2/+, Zn/sub 2/+, Ni/sub 2/+ and Co/sub 2/+ were determined through polarography. Out of which pairs of Fe/sub 2/+Zn/sub 2/+ and Ni/sub 2/+Co/sub 2/+ were determined in two separate runs while Cd/sub 2/+, Pb/sub 2/+, Cu/sub 2/+ were analyzed in single run of ASV. Sensitivity and speciation capabilities of voltammetric methods have been employed. Analysis conditions were optimized that includes selection of supporting electrolyte, pH, working electrodes, sweep rate etc. Stripping voltammetry was adopted for analysis at ultra trace levels. Statistical parameters for analytical method development like selectivity factor, interference, repeatability (0.0065-0.130 macro g/g), reproducibility (0.08125-1.625 macro g/g), detection limits (0.032-5.06 macro g/g), limits of quantification (0.081-12.652 macro g/g), sensitivities (5.636-2.15 nA mL macro g-1) etc. were also determined. The percentage recoveries were found in between 95-105% using certified reference materials. Real samples of complex marine environment from Karachi coastline were also analyzed. The standard addition method was employed where any matrix effect was evidenced. (author)

  17. Macro elemental analysis of food samples by nuclear analytical technique

    Science.gov (United States)

    Syahfitri, W. Y. N.; Kurniawati, S.; Adventini, N.; Damastuti, E.; Lestiani, D. D.

    2017-06-01

    Energy-dispersive X-ray fluorescence (EDXRF) spectrometry is a non-destructive, rapid, multi elemental, accurate, and environment friendly analysis compared with other detection methods. Thus, EDXRF spectrometry is applicable for food inspection. The macro elements calcium and potassium constitute important nutrients required by the human body for optimal physiological functions. Therefore, the determination of Ca and K content in various foods needs to be done. The aim of this work is to demonstrate the applicability of EDXRF for food analysis. The analytical performance of non-destructive EDXRF was compared with other analytical techniques; neutron activation analysis and atomic absorption spectrometry. Comparison of methods performed as cross checking results of the analysis and to overcome the limitations of the three methods. Analysis results showed that Ca found in food using EDXRF and AAS were not significantly different with p-value 0.9687, whereas p-value of K between EDXRF and NAA is 0.6575. The correlation between those results was also examined. The Pearson correlations for Ca and K were 0.9871 and 0.9558, respectively. Method validation using SRM NIST 1548a Typical Diet was also applied. The results showed good agreement between methods; therefore EDXRF method can be used as an alternative method for the determination of Ca and K in food samples.

  18. A two-hypothesis approach to establishing a life detection/biohazard protocol for planetary samples

    Science.gov (United States)

    Conley, Catharine; Steele, Andrew

    2016-07-01

    The COSPAR policy on performing a biohazard assessment on samples brought from Mars to Earth is framed in the context of a concern for false-positive results. However, as noted during the 2012 Workshop for Life Detection in Samples from Mars (ref. Kminek et al., 2014), a more significant concern for planetary samples brought to Earth is false-negative results, because an undetected biohazard could increase risk to the Earth. This is the reason that stringent contamination control must be a high priority for all Category V Restricted Earth Return missions. A useful conceptual framework for addressing these concerns involves two complementary 'null' hypotheses: testing both of them, together, would allow statistical and community confidence to be developed regarding one or the other conclusion. As noted above, false negatives are of primary concern for safety of the Earth, so the 'Earth Safety null hypothesis' -- that must be disproved to assure low risk to the Earth from samples introduced by Category V Restricted Earth Return missions -- is 'There is native life in these samples.' False positives are of primary concern for Astrobiology, so the 'Astrobiology null hypothesis' -- that must be disproved in order to demonstrate the existence of extraterrestrial life is 'There is no life in these samples.' The presence of Earth contamination would render both of these hypotheses more difficult to disprove. Both these hypotheses can be tested following a strict science protocol; analyse, interprete, test the hypotheses and repeat. The science measurements undertaken are then done in an iterative fashion that responds to discovery with both hypotheses testable from interpretation of the scientific data. This is a robust, community involved activity that ensures maximum science return with minimal sample use.

  19. TECHNIQUES WITH POTENTIAL FOR HANDLING ENVIRONMENTAL SAMPLES IN CAPILLARY ELECTROPHORESIS

    Science.gov (United States)

    An assessment of the methods for handling environmental samples prior to capillary electrophoresis (CE) is presented for both aqueous and solid matrices. Sample handling in environmental analyses is the subject of ongoing research at the Environmental Protection Agency's National...

  20. Sampling Polya-Gamma random variates: alternate and approximate techniques

    OpenAIRE

    Windle, Jesse; Polson, Nicholas G.; Scott, James G.

    2014-01-01

    Efficiently sampling from the P\\'olya-Gamma distribution, ${PG}(b,z)$, is an essential element of P\\'olya-Gamma data augmentation. Polson et. al (2013) show how to efficiently sample from the ${PG}(1,z)$ distribution. We build two new samplers that offer improved performance when sampling from the ${PG}(b,z)$ distribution and $b$ is not unity.

  1. Manipulation of biological samples using micro and nano techniques

    DEFF Research Database (Denmark)

    Castillo, Jaime; Dimaki, Maria; Svendsen, Winnie Edith

    2009-01-01

    to their natural structure. Thanks to the advances in micro- and nanofabrication during the last decades several manipulation techniques offer us the possibility to image, characterize and manipulate biological material in a controlled way. Using these techniques the integration of biomaterials with remarkable...

  2. Rehabilitation with 4 zygomatic implants with a new surgical protocol using ultrasonic technique.

    Science.gov (United States)

    Mozzati, Marco; Mortellaro, Carmen; Arata, Valentina; Gallesio, Giorgia; Previgliano, Valter

    2015-05-01

    When the residual bone crest cannot allow the placement of standard implants, the treatment for complete arch rehabilitation of severely atrophic maxillae can be performed with 4 zygomatic implants (ZIs) and immediate function with predictable results in terms of aesthetics, function, and comfort for the patient. However, even if ZIs' rehabilitations showed a good success rate, this surgery is difficult and need a skillful operator. Complications in this kind of rehabilitation are not uncommon; the main difficulties can be related to the reduced surgical visibility and instrument control in a critical anatomic area. All the surgical protocols described in the literature used drilling techniques. Furthermore, the use of ultrasonic instruments in implant surgery compared with drilling instruments have shown advantages in many aspects of surgical procedures, tissues management, enhancement of control, surgical visualization, and healing. The aim of this study was to report on the preliminary experience using ultrasound technique for ZIs surgery in terms of safety and technical improvement. Ten consecutive patients with severely atrophic maxilla have been treated with 4 ZIs and immediate complete arch acrylic resin provisional prostheses. The patients were followed up from 30 to 32 months evaluating implant success, prosthetic success, and patient satisfaction with a questionnaire. No implants were lost during the study period, with a 100% implant and prosthetic success rate. Within the limitations of this preliminary study, these data indicate that ultrasonic implant site preparation for ZIs can be a good alternative to the drilling technique and an improvement for the surgeon.

  3. Statistical sampling techniques as applied to OSE inspections

    International Nuclear Information System (INIS)

    Davis, J.J.; Cote, R.W.

    1987-01-01

    The need has been recognized for statistically valid methods for gathering information during OSE inspections; and for interpretation of results, both from performance testing and from records reviews, interviews, etc. Battelle Columbus Division, under contract to DOE OSE has performed and is continuing to perform work in the area of statistical methodology for OSE inspections. This paper represents some of the sampling methodology currently being developed for use during OSE inspections. Topics include population definition, sample size requirements, level of confidence and practical logistical constraints associated with the conduct of an inspection based on random sampling. Sequential sampling schemes and sampling from finite populations are also discussed. The methods described are applicable to various data gathering activities, ranging from the sampling and examination of classified documents to the sampling of Protective Force security inspectors for skill testing

  4. A simple air sampling technique for monitoring nitrous oxide pollution

    Energy Technology Data Exchange (ETDEWEB)

    Austin, J C; Shaw, R; Moyes, D; Cleaton-Jones, P E

    1981-01-01

    A simple, inexpensive device for the continuous low-flow sampling of air was devised to permit monitoring of pollution by gaseous anaesthetics. The device consisted of a water-filled Perspex cylinder in which a double-walled flexible-film gas sample collection bag was suspended. Air samples could be aspirated into the collection bag at flow rates of as low as 1 ml min-1 by allowing the water to drain from the cylinder at a controlled rate. The maintenance of sample integrity with aspiration and storage of samples of nitrous oxide in air at concentrations of 1000, 100 and 30 p.p.m. v/v was examined using gas chromatography. The sample bags retained a mean 94% of the nitrous oxide in air samples containing nitrous oxide 25 p.p.m. over a 72-h storage period.

  5. Equipment and techniques for remote sampling of stored radioactive waste

    International Nuclear Information System (INIS)

    Nance, T.A.

    1996-01-01

    Several tools have been developed at the Savannah River Site (SRS) to remotely sample stored radioactive waste. These sampling tools have been developed to determine the chemical characteristics of the waste prior to processing. The processing of waste material varies according to the chemical characteristics of the waste, which change due to additions, settling, mixing, and chemical reactions during storage. Once the waste has been sampled to identify its characteristics, the chemical composition of the waste can then be altered if needed to prepare for processing. Various types of waste material in several types of containment must be sampled at SRS. Stored waste materials consist of liquids, floating organics, sludge, salt and solids. Waste is stored in four basic types of tanks with different means of access and interior obstructions. The waste tanks can only be accessed by small openings: access ports, risers and downcomers. Requirements for sampling depend on the type of tank being accessed, the waste within the tank, and the particular location in the tank desired for taking the sample. Sampling devices have been developed to sample all of the waste material forms found in the SRS tank farms. The fluid type samplers are capable of sampling surface liquid, subsurface liquid at varying depth, surface sludge, subsurface sludge, and floating organics. The solid type samplers are capable of sampling salt, sampling a solid layer on the bottom of the tank, and capturing a small solid mass on the tank bottom. The sampling devices are all designed to access the tanks through small access ports. The samplers are reusable and are designed to allow quick transfer of the samples to shielded packaging for transport, reducing the amount of radiation exposure to sampling personnel. The samplers weigh less than 100 lb. and are designed in sections to allow easy disassembly for storage and transport by personnel. (Abstract Truncated)

  6. Protocol for Measuring the Thermal Properties of a Supercooled Synthetic Sand-water-gas-methane Hydrate Sample.

    Science.gov (United States)

    Muraoka, Michihiro; Susuki, Naoko; Yamaguchi, Hiroko; Tsuji, Tomoya; Yamamoto, Yoshitaka

    2016-03-21

    Methane hydrates (MHs) are present in large amounts in the ocean floor and permafrost regions. Methane and hydrogen hydrates are being studied as future energy resources and energy storage media. To develop a method for gas production from natural MH-bearing sediments and hydrate-based technologies, it is imperative to understand the thermal properties of gas hydrates. The thermal properties' measurements of samples comprising sand, water, methane, and MH are difficult because the melting heat of MH may affect the measurements. To solve this problem, we performed thermal properties' measurements at supercooled conditions during MH formation. The measurement protocol, calculation method of the saturation change, and tips for thermal constants' analysis of the sample using transient plane source techniques are described here. The effect of the formation heat of MH on measurement is very small because the gas hydrate formation rate is very slow. This measurement method can be applied to the thermal properties of the gas hydrate-water-guest gas system, which contains hydrogen, CO2, and ozone hydrates, because the characteristic low formation rate of gas hydrate is not unique to MH. The key point of this method is the low rate of phase transition of the target material. Hence, this method may be applied to other materials having low phase-transition rates.

  7. Centrifugation protocols: tests to determine optimal lithium heparin and citrate plasma sample quality.

    Science.gov (United States)

    Dimeski, Goce; Solano, Connie; Petroff, Mark K; Hynd, Matthew

    2011-05-01

    Currently, no clear guidelines exist for the most appropriate tests to determine sample quality from centrifugation protocols for plasma sample types with both lithium heparin in gel barrier tubes for biochemistry testing and citrate tubes for coagulation testing. Blood was collected from 14 participants in four lithium heparin and one serum tube with gel barrier. The plasma tubes were centrifuged at four different centrifuge settings and analysed for potassium (K(+)), lactate dehydrogenase (LD), glucose and phosphorus (Pi) at zero time, poststorage at six hours at 21 °C and six days at 2-8°C. At the same time, three citrate tubes were collected and centrifuged at three different centrifuge settings and analysed immediately for prothrombin time/international normalized ratio, activated partial thromboplastin time, derived fibrinogen and surface-activated clotting time (SACT). The biochemistry analytes indicate plasma is less stable than serum. Plasma sample quality is higher with longer centrifugation time, and much higher g force. Blood cells present in the plasma lyse with time or are damaged when transferred in the reaction vessels, causing an increase in the K(+), LD and Pi above outlined limits. The cells remain active and consume glucose even in cold storage. The SACT is the only coagulation parameter that was affected by platelets >10 × 10(9)/L in the citrate plasma. In addition to the platelet count, a limited but sensitive number of assays (K(+), LD, glucose and Pi for biochemistry, and SACT for coagulation) can be used to determine appropriate centrifuge settings to consistently obtain the highest quality lithium heparin and citrate plasma samples. The findings will aid laboratories to balance the need to provide the most accurate results in the best turnaround time.

  8. Minimal sampling protocol for accurate estimation of urea production: a study with oral [13C]urea in fed and fasted piglets

    NARCIS (Netherlands)

    Oosterveld, Michiel J. S.; Gemke, Reinoud J. B. J.; Dainty, Jack R.; Kulik, Willem; Jakobs, Cornelis; de Meer, Kees

    2005-01-01

    An oral [13C]urea protocol may provide a simple method for measurement of urea production. The validity of single pool calculations in relation to a reduced sampling protocol was assessed. In eight fed and five fasted piglets, plasma urea enrichments from a 10 h sampling protocol were measured

  9. Reliability of diagnostic imaging techniques in suspected acute appendicitis: proposed diagnostic protocol

    International Nuclear Information System (INIS)

    Cura del, J. L.; Oleaga, L.; Grande, D.; Vela, A. C.; Ibanez, A. M.

    2001-01-01

    To study the utility of ultrasound and computed tomography (CT) in case of suspected appendicitis. To determine the diagnostic yield in terms of different clinical contexts and patient characteristics. to assess the costs and benefits of introducing these techniques and propose a protocol for their use. Negative appendectomies, complications and length of hospital stay in a group of 152 patients with suspected appendicitis who underwent ultrasound and CT were compared with those of 180 patients who underwent appendectomy during the same time period, but had not been selected for the first group: these patients costs for each group were calculated. In the first group, the diagnostic value of the clinical signs was also evaluated. The reliability of the clinical signs was limited, while the results with ultrasound and CT were excellent. The incidence of negative appendectomy was 9.6% in the study group and 12.2% in the control group. Moreover, there were fewer complications and a shorter hospital stay in the first group. Among men, however, the rate of negative appendectomy was lower in the control group. The cost of using ultrasound and CT in the management of appendicitis was only slightly higher than that of the control group. Although ultrasound and CT are not necessary in cases in which the probability of appendicitis is low or in men presenting clear clinical evidence, the use of these techniques is indicated in the remaining cases in which appendicitis is suspected. In children, ultrasound is the technique of choice. In all other patients, if negative results are obtained with one of the two techniques, the other should be performed. (Author) 49 refs

  10. Split bolus technique in polytrauma: a prospective study on scan protocols for trauma analysis

    NARCIS (Netherlands)

    Beenen, Ludo F. M.; Sierink, Joanne C.; Kolkman, Saskia; Nio, C. Yung; Saltzherr, Teun Peter; Dijkgraaf, Marcel G. W.; Goslings, J. Carel

    2015-01-01

    For the evaluation of severely injured trauma patients a variety of total body computed tomography (CT) scanning protocols exist. Frequently multiple pass protocols are used. A split bolus contrast protocol can reduce the number of passes through the body, and thereby radiation exposure, in this

  11. MRI technique for the preoperative evaluation of deep infiltrating endometriosis: current status and protocol recommendation

    International Nuclear Information System (INIS)

    Schneider, C.; Oehmke, F.; Tinneberg, H.-R.; Krombach, G.A.

    2016-01-01

    Endometriosis is a common cause of chronic pelvic pain and infertility. It is defined as the occurrence of endometrial tissue outside the uterine cavity and can manifest as a peritoneal, ovarian or infiltrating form, the latter being referred to as deep infiltrating endometriosis (DIE). Surgery is essential in the treatment of DIE and depending on the severity of the disease, surgery can be difficult and extensive. Beside clinical examination and ultrasound, magnetic resonance imaging (MRI) has proven its value to provide useful information for planning surgery in patients with suspected DIE. To optimise the quality of MRI examinations, radiologists have to be familiar with the capabilities and also the limitations of this technique with respect to the assessment of DIE. MRI yields morphological information by using mainly T1- and T2-weighted sequences, but can also provide functional information by means of intravenous gadolinium, diffusion-weighted imaging or cine-MRI. In this article, these techniques and also adequate measures of patient preparation, which are indispensable for successful MRI imaging for the preoperative evaluation of DIE, are reviewed and a comprehensive protocol recommendation is provided.

  12. Comparison of sampling techniques for Rift Valley Fever virus ...

    African Journals Online (AJOL)

    time for trapping potential vectors for Rift Valley Fever virus. ..... Krockel, U., Rose, A., Eiras, A.E. & Geier, M. (2006) New tools for surveillance of adult yellow fever ... baited trapping systems for sampling outdoor mosquito populations in ...

  13. A non-destructive DNA sampling technique for herbarium specimens.

    Science.gov (United States)

    Shepherd, Lara D

    2017-01-01

    Herbarium specimens are an important source of DNA for plant research but current sampling methods require the removal of material for DNA extraction. This is undesirable for irreplaceable specimens such as rare species or type material. Here I present the first non-destructive sampling method for extracting DNA from herbarium specimens. DNA was successfully retrieved from robust leaves and/or stems of herbarium specimens up to 73 years old.

  14. Sample preparation techniques of biological material for isotope analysis

    International Nuclear Information System (INIS)

    Axmann, H.; Sebastianelli, A.; Arrillaga, J.L.

    1990-01-01

    Sample preparation is an essential step in all isotope-aided experiments but often it is not given enough attention. The methods of sample preparation are very important to obtain reliable and precise analytical data and for further interpretation of results. The size of a sample required for chemical analysis is usually very small (10mg-1500mg). On the other hand the amount of harvested plant material from plots in a field experiment is often bulky (several kilograms) and the entire sample is too large for processing. In addition, while approaching maturity many crops show not only differences in physical consistency but also a non-uniformity in 15 N content among plant parts, requiring a plant fractionation or separation into parts (vegetative and reproductive) e.g. shoots and spikes, in case of small grain cereals, shoots and pods in case of grain legumes and tops and roots or beets (including crown) in case of sugar beet, etc. In any case the ultimate goal of these procedures is to obtain representative subsample harvested from greenhouse or field experiments for chemical analysis. Before harvesting an isotopic-aided experiment the method of sampling has to be selected. It should be based on the type of information required in relation to the objectives of the research and the availability of resources (staff, sample preparation equipment, analytical facilities, chemicals and supplies, etc.). 10 refs, 3 figs, 3 tabs

  15. Comparison of sampling techniques for Bayesian parameter estimation

    Science.gov (United States)

    Allison, Rupert; Dunkley, Joanna

    2014-02-01

    The posterior probability distribution for a set of model parameters encodes all that the data have to tell us in the context of a given model; it is the fundamental quantity for Bayesian parameter estimation. In order to infer the posterior probability distribution we have to decide how to explore parameter space. Here we compare three prescriptions for how parameter space is navigated, discussing their relative merits. We consider Metropolis-Hasting sampling, nested sampling and affine-invariant ensemble Markov chain Monte Carlo (MCMC) sampling. We focus on their performance on toy-model Gaussian likelihoods and on a real-world cosmological data set. We outline the sampling algorithms themselves and elaborate on performance diagnostics such as convergence time, scope for parallelization, dimensional scaling, requisite tunings and suitability for non-Gaussian distributions. We find that nested sampling delivers high-fidelity estimates for posterior statistics at low computational cost, and should be adopted in favour of Metropolis-Hastings in many cases. Affine-invariant MCMC is competitive when computing clusters can be utilized for massive parallelization. Affine-invariant MCMC and existing extensions to nested sampling naturally probe multimodal and curving distributions.

  16. Study of gastric cancer samples using terahertz techniques

    Science.gov (United States)

    Wahaia, Faustino; Kasalynas, Irmantas; Seliuta, Dalius; Molis, Gediminas; Urbanowicz, Andrzej; Carvalho Silva, Catia D.; Carneiro, Fatima; Valusis, Gintaras; Granja, Pedro L.

    2014-08-01

    In the present work, samples of healthy and adenocarcinoma-affected human gastric tissue were analyzed using transmission time-domain THz spectroscopy (THz-TDS) and spectroscopic THz imaging at 201 and 590 GHz. The work shows that it is possible to distinguish between normal and cancerous regions in dried and paraffin-embedded samples. Plots of absorption coefficient α and refractive index n of normal and cancer affected tissues, as well as 2-D transmission THz images are presented and the conditions for discrimination between normal and affected tissues are discussed.

  17. Electrodeposition as a sample preparation technique for TXRF analysis

    International Nuclear Information System (INIS)

    Griesel, S.; Reus, U.; Prange, A.

    2000-01-01

    TXRF analysis of trace elements at concentrations in the μg/L range and below in high salt matrices normally requires a number of sample preparation steps that include separation of the salt matrix and preconcentration of the trace elements. A neat approach which allows samples to be prepared straightforwardly in a single step involves the application of electrochemical deposition using the TXRF sample support itself as an electrode. For this work a common three-electrode arrangement (radiometer analytical) with a rotating disc electrode as the working electrode, as is frequently employed in voltametric analysis, has been used. A special electrode tip has been constructed as a holder for the sample carrier which consists of polished glassy carbon. This material has been proven to be suitable for both its electrical and chemical properties. Measurements of the trace elements were performed using the ATOMIKA 8030C TXRF spectrometer, with the option of variable incident angles. In first experiments an artificial sea water matrix containing various trace elements in the μg/L range has been used. Elements such as Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Hg, and Pb deposited on glassy carbon carriers. The deposition can be optimized by controlling the potential of the working electrode with respect to the reference electrode. Metal ions with a suitable standard potential are reduced to the metallic state and plated onto the electrode surface. When deposition is finished the sample carrier is demounted, rinsed with ultra-pure water and measured directly. Deposition yields for the elements under investigation are quite similar, and with an appropriate choice of the reference element, quantification can be achieved directly by internal standardization. The influence of parameters such as time, pH value, and trace element concentration on the deposition yield has been examined, and the results will be presented along with reproducibility studies. (author)

  18. An On-Target Desalting and Concentration Sample Preparation Protocol for MALDI-MS and MS/MS Analysis

    DEFF Research Database (Denmark)

    Zhang, Xumin; Wang, Quanhui; Lou, Xiaomin

    2012-01-01

    2DE coupled with MALDI-MS is one of the most widely used and powerful analytic technologies in proteomics study. The MALDI sample preparation method has been developed and optimized towards the combination of simplicity, sample-cleaning, and sample concentration since its introduction. Here we...... present a protocol of the so-called Sample loading, Matrix loading, and on-target Wash (SMW) method which fulfills the three criteria by taking advantage of the AnchorChip™ targets. Our method is extremely simple and no pre-desalting or concentration is needed when dealing with samples prepared from 2DE...

  19. Bioassay techniques for {sup 55}Fe in urine samples

    Energy Technology Data Exchange (ETDEWEB)

    Cregan, S P; Leon, J W; Linauskas, S H

    1993-11-01

    Solvent extraction, ion chromatography and several rapid screening methods were developed and evaluated for {sup 55}Fe bioassay applications. Isopropyl ether and TNOA column extractions had radiochemical recoveries exceeding 90%. These were very reproducible with a coefficient of variation less than 5%. Screening techniques investigated included direct counting of ashed urine solids, and Fe(OH){sub 3}. precipitated from urine. The sensitivities (2-50 Bq/d urine) of the screening methods were usually limited by the effective urine volume that could be counted in a liquid scintillation counter. The reference isopropyl ether and chromatography methods could easily achieve sensitivities well below the 1 Bq/d urine output target. (author). 49 refs., 3 tabs., 5 figs.

  20. Bioassay techniques for 55Fe in urine samples

    International Nuclear Information System (INIS)

    Cregan, S.P.; Leon, J.W.; Linauskas, S.H.

    1993-11-01

    Solvent extraction, ion chromatography and several rapid screening methods were developed and evaluated for 55 Fe bioassay applications. Isopropyl ether and TNOA column extractions had radiochemical recoveries exceeding 90%. These were very reproducible with a coefficient of variation less than 5%. Screening techniques investigated included direct counting of ashed urine solids, and Fe(OH) 3 . precipitated from urine. The sensitivities (2-50 Bq/d urine) of the screening methods were usually limited by the effective urine volume that could be counted in a liquid scintillation counter. The reference isopropyl ether and chromatography methods could easily achieve sensitivities well below the 1 Bq/d urine output target. (author). 49 refs., 3 tabs., 5 figs

  1. Image acquisition system using on sensor compressed sampling technique

    Science.gov (United States)

    Gupta, Pravir Singh; Choi, Gwan Seong

    2018-01-01

    Advances in CMOS technology have made high-resolution image sensors possible. These image sensors pose significant challenges in terms of the amount of raw data generated, energy efficiency, and frame rate. This paper presents a design methodology for an imaging system and a simplified image sensor pixel design to be used in the system so that the compressed sensing (CS) technique can be implemented easily at the sensor level. This results in significant energy savings as it not only cuts the raw data rate but also reduces transistor count per pixel; decreases pixel size; increases fill factor; simplifies analog-to-digital converter, JPEG encoder, and JPEG decoder design; decreases wiring; and reduces the decoder size by half. Thus, CS has the potential to increase the resolution of image sensors for a given technology and die size while significantly decreasing the power consumption and design complexity. We show that it has potential to reduce power consumption by about 23% to 65%.

  2. Monitoring well design and sampling techniques at NAPL sites

    International Nuclear Information System (INIS)

    Collins, M.; Rohrman, W.R.; Drake, K.D.

    1992-01-01

    The existence of Non-Aqueous Phase Liquids (NAPLs) at many Superfund and RCRA hazardous waste sites has become a recognized problem in recent years. The large number of sites exhibiting this problem results from the fact that many of the most frequently used industrial solvents and petroleum products can exist as NAPLs. Hazardous waste constituents occurring as NAPLs possess a common characteristic that causes great concern during groundwater contamination evaluation: while solubility in water is generally very low, it is sufficient to cause groundwater to exceed Maximum Contamination Levels (MCLs). Thus, even a small quantity of NAPL within a groundwater regime can act as a point source with the ability to contaminate vast quantities of groundwater over time. This property makes it imperative that groundwater investigations focus heavily on characterizing the nature, extent, and migration pathways of NAPLs at sites where it exists. Two types of NAPLs may exist in a groundwater system. Water-immiscible liquid constituents having a specific gravity greater than one are termed Dense Non-Aqueous Phase Liquids, while those with a specific gravity less than one are considered Light Non-Aqueous Phase Liquids. For a groundwater investigation to properly characterize the two types of NAPLs, careful consideration must be given to the placement and sampling of groundwater monitoring wells. Unfortunately, technical reviewers at EPA Region VII and the Corps of Engineers find that many groundwater investigations fall short in characterizing NAPLs because several basic considerations were overlooked. Included among these are monitoring well location and screen placement with respect to the water table and significant confining units, and the ability of the well sampling method to obtain samples of NAPL. Depending on the specific gravity of the NAPL that occurs at a site, various considerations can substantially enhance adequate characterization of NAPL contaminants

  3. Efficient DNP NMR of Membrane Proteins: Sample Preparation Protocols, Sensitivity, and Radical Location

    Science.gov (United States)

    Liao, Shu Y.; Lee, Myungwoon; Wang, Tuo; Sergeyev, Ivan V.; Hong, Mei

    2016-01-01

    Although dynamic nuclear polarization (DNP) has dramatically enhanced solid-state NMR spectral sensitivities of many synthetic materials and some biological macromolecules, recent studies of membrane-protein DNP using exogenously doped paramagnetic radicals as polarizing agents have reported varied and sometimes surprisingly limited enhancement factors. This motivated us to carry out a systematic evaluation of sample preparation protocols for optimizing the sensitivity of DNP NMR spectra of membrane-bound peptides and proteins at cryogenic temperatures of ~110 K. We show that mixing the radical with the membrane by direct titration instead of centrifugation gives a significant boost to DNP enhancement. We quantify the relative sensitivity enhancement between AMUPol and TOTAPOL, two commonly used radicals, and between deuterated and protonated lipid membranes. AMUPol shows ~4 fold higher sensitivity enhancement than TOTAPOL, while deuterated lipid membrane does not give net higher sensitivity for the membrane peptides than protonated membrane. Overall, a ~100 fold enhancement between the microwave-on and microwave-off spectra can be achieved on lipid-rich membranes containing conformationally disordered peptides, and absolute sensitivity gains of 105–160 can be obtained between low-temperature DNP spectra and high-temperature non-DNP spectra. We also measured the paramagnetic relaxation enhancement of lipid signals by TOTAPOL and AMUPol, to determine the depths of these two radicals in the lipid bilayer. Our data indicate a bimodal distribution of both radicals, a surface-bound fraction and a membrane-bound fraction where the nitroxides lie at ~10 Å from the membrane surface. TOTAPOL appears to have a higher membrane-embedded fraction than AMUPol. These results should be useful for membrane-protein solid-state NMR studies under DNP conditions and provide insights into how biradicals interact with phospholipid membranes. PMID:26873390

  4. Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Shu Y.; Lee, Myungwoon; Wang, Tuo [Massachusetts Institute of Technology, Department of Chemistry (United States); Sergeyev, Ivan V. [Bruker Biospin (United States); Hong, Mei, E-mail: meihong@mit.edu [Massachusetts Institute of Technology, Department of Chemistry (United States)

    2016-03-15

    Although dynamic nuclear polarization (DNP) has dramatically enhanced solid-state NMR spectral sensitivities of many synthetic materials and some biological macromolecules, recent studies of membrane-protein DNP using exogenously doped paramagnetic radicals as polarizing agents have reported varied and sometimes surprisingly limited enhancement factors. This motivated us to carry out a systematic evaluation of sample preparation protocols for optimizing the sensitivity of DNP NMR spectra of membrane-bound peptides and proteins at cryogenic temperatures of ~110 K. We show that mixing the radical with the membrane by direct titration instead of centrifugation gives a significant boost to DNP enhancement. We quantify the relative sensitivity enhancement between AMUPol and TOTAPOL, two commonly used radicals, and between deuterated and protonated lipid membranes. AMUPol shows ~fourfold higher sensitivity enhancement than TOTAPOL, while deuterated lipid membrane does not give net higher sensitivity for the membrane peptides than protonated membrane. Overall, a ~100 fold enhancement between the microwave-on and microwave-off spectra can be achieved on lipid-rich membranes containing conformationally disordered peptides, and absolute sensitivity gains of 105–160 can be obtained between low-temperature DNP spectra and high-temperature non-DNP spectra. We also measured the paramagnetic relaxation enhancement of lipid signals by TOTAPOL and AMUPol, to determine the depths of these two radicals in the lipid bilayer. Our data indicate a bimodal distribution of both radicals, a surface-bound fraction and a membrane-bound fraction where the nitroxides lie at ~10 Å from the membrane surface. TOTAPOL appears to have a higher membrane-embedded fraction than AMUPol. These results should be useful for membrane-protein solid-state NMR studies under DNP conditions and provide insights into how biradicals interact with phospholipid membranes.

  5. Sampling hydrometeors in clouds in-situ - the replicator technique

    Science.gov (United States)

    Wex, Heike; Löffler, Mareike; Griesche, Hannes; Bühl, Johannes; Stratmann, Frank; Schmitt, Carl; Dirksen, Ruud; Reichardt, Jens; Wolf, Veronika; Kuhn, Thomas; Prager, Lutz; Seifert, Patric

    2017-04-01

    For the examination of ice crystals in clouds, concerning their number concentrations, sizes and shapes, often instruments mounted on fast flying aircraft are used. One related disadvantage is possible shattering of the ice crystals on inlets, which has been improved with the introduction of the "Korolev-tip" and by accounting for inter-arrival times (Korolev et al., 2013, 2015), but additionally, the typically fast flying aircraft allow only for a low spatial resolution. Alternative sampling methods have been introduced as e.g., a replicator by Miloshevich & Heymsfield (1997) and an in-situ imager by by Kuhn & Heymsfield (2016). They both sample ice crystals onto an advancing stripe while ascending on a balloon, conserving the ice crystals either in formvar for later off-line analysis under a microscope (Miloshevich & Heymsfield, 1997) or imaging them upon their impaction on silicone oil (Kuhn & Heymsfield, 2016), both yielding vertical profiles for different ice crystal properties. A measurement campaign was performed at the Lindenberg Meteorological Observatory of the German Meteorological Service (DWD) in Germany in October 2016, during which both types of instruments were used during balloon ascents, while ground-based Lidar and cloud-radar measurements were performed simultaneously. The two ice particle sondes were operated by people from the Lulea University of Technology and from TROPOS, where the latter one was made operational only recently. Here, we will show first results of the TROPOS replicator on ice crystals sampled during one ascent, for which the collected ice crystals were analyzed off-line using a microscope. Literature: Korolev, A., E. Emery, and K. Creelman (2013), Modification and tests of particle probe tips to mitigate effects of ice shattering, J. Atmos. Ocean. Tech., 30, 690-708, 2013. Korolev, A., and P. R. Field (2015), Assessment of the performance of the inter-arrival time algorithm to identify ice shattering artifacts in cloud

  6. The surface elevation table and marker horizon technique: A protocol for monitoring wetland elevation dynamics

    Science.gov (United States)

    James C. Lynch,; Phillippe Hensel,; Cahoon, Donald R.

    2015-01-01

    The National Park Service, in response to the growing evidence and awareness of the effects of climate change on federal lands, determined that monitoring wetland elevation change is a top priority in North Atlantic Coastal parks (Stevens et al, 2010). As a result, the NPS Northeast Coastal and Barrier Network (NCBN) in collaboration with colleagues from the U.S. Geological Survey (USGS) and The National Oceanic and Atmospheric Administration (NOAA) have developed a protocol for monitoring wetland elevation change and other processes important for determining the viability of wetland communities. Although focused on North Atlantic Coastal parks, this document is applicable to all coastal and inland wetland regions. Wetlands exist within a narrow range of elevation which is influenced by local hydrologic conditions. For coastal wetlands in particular, local hydrologic conditions may be changing as sea levels continue to rise. As sea level rises, coastal wetland systems may respond by building elevation to maintain favorable hydrologic conditions for their survival. This protocol provides the reader with instructions and guidelines on designing a monitoring plan or study to: A) Quantify elevation change in wetlands with the Surface Elevation Table (SET). B) Understand the processes that influence elevation change, including vertical accretion (SET and Marker Horizon methods). C) Survey the wetland surface and SET mark to a common reference datum to allow for comparing sample stations to each other and to local tidal datums. D) Survey the SET mark to monitor its relative stability. This document is divided into two parts; the main body that presents an overview of all aspects of monitoring wetland elevation dynamics, and a collection of Standard Operating Procedures (SOP) that describes in detail how to perform or execute each step of the methodology. Detailed instruction on the installation, data collection, data management and analysis are provided in this report

  7. Effect of joint mobilization techniques for primary total knee arthroplasty: Study protocol for a randomized controlled trial.

    Science.gov (United States)

    Xu, Jiao; Zhang, Juan; Wang, Xue-Qiang; Wang, Xuan-Lin; Wu, Ya; Chen, Chan-Cheng; Zhang, Han-Yu; Zhang, Zhi-Wan; Fan, Kai-Yi; Zhu, Qiang; Deng, Zhi-Wei

    2017-12-01

    Total knee arthroplasty (TKA) has become the most preferred procedure by patients for the relief of pain caused by knee osteoarthritis. TKA patients aim a speedy recovery after the surgery. Joint mobilization techniques for rehabilitation have been widely used to relieve pain and improve joint mobility. However, relevant randomized controlled trials showing the curative effect of these techniques remain lacking to date. Accordingly, this study aims to investigate whether joint mobilization techniques are valid for primary TKA. We will manage a single-blind, prospective, randomized, controlled trial of 120 patients with unilateral TKA. Patients will be randomized into an intervention group, a physical modality therapy group, and a usual care group. The intervention group will undergo joint mobilization manipulation treatment once a day and regular training twice a day for a month. The physical modality therapy group will undergo physical therapy once a day and regular training twice a day for a month. The usual care group will perform regular training twice a day for a month. Primary outcome measures will be based on the visual analog scale, the knee joint Hospital for Special Surgery score, range of motion, surrounded degree, and adverse effect. Secondary indicators will include manual muscle testing, 36-Item Short Form Health Survey, Berg Balance Scale function evaluation, Pittsburgh Sleep Quality Index, proprioception, and muscle morphology. We will direct intention-to-treat analysis if a subject withdraws from the trial. The important features of this trial for joint mobilization techniques in primary TKA are randomization procedures, single-blind, large sample size, and standardized protocol. This study aims to investigate whether joint mobilization techniques are effective for early TKA patients. The result of this study may serve as a guide for TKA patients, medical personnel, and healthcare decision makers. It has been registered at http

  8. Comparing rapid methods for detecting Listeria in seafood and environmental samples using the most probably number (MPN) technique.

    Science.gov (United States)

    Cruz, Cristina D; Win, Jessicah K; Chantarachoti, Jiraporn; Mutukumira, Anthony N; Fletcher, Graham C

    2012-02-15

    The standard Bacteriological Analytical Manual (BAM) protocol for detecting Listeria in food and on environmental surfaces takes about 96 h. Some studies indicate that rapid methods, which produce results within 48 h, may be as sensitive and accurate as the culture protocol. As they only give presence/absence results, it can be difficult to compare the accuracy of results generated. We used the Most Probable Number (MPN) technique to evaluate the performance and detection limits of six rapid kits for detecting Listeria in seafood and on an environmental surface compared with the standard protocol. Three seafood products and an environmental surface were inoculated with similar known cell concentrations of Listeria and analyzed according to the manufacturers' instructions. The MPN was estimated using the MPN-BAM spreadsheet. For the seafood products no differences were observed among the rapid kits and efficiency was similar to the BAM method. On the environmental surface the BAM protocol had a higher recovery rate (sensitivity) than any of the rapid kits tested. Clearview™, Reveal®, TECRA® and VIDAS® LDUO detected the cells but only at high concentrations (>10(2) CFU/10 cm(2)). Two kits (VIP™ and Petrifilm™) failed to detect 10(4) CFU/10 cm(2). The MPN method was a useful tool for comparing the results generated by these presence/absence test kits. There remains a need to develop a rapid and sensitive method for detecting Listeria in environmental samples that performs as well as the BAM protocol, since none of the rapid tests used in this study achieved a satisfactory result. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Comparative analysis of five DNA isolation protocols and three drying methods for leaves samples of Nectandra megapotamica (Spreng. Mez

    Directory of Open Access Journals (Sweden)

    Leonardo Severo da Costa

    2016-06-01

    Full Text Available The aim of the study was to establish a DNA isolation protocol Nectandra megapotamica (Spreng. Mez., able to obtain samples of high yield and quality for use in genomic analysis. A commercial kit and four classical methods of DNA extraction were tested, including three cetyltrimethylammonium bromide (CTAB-based and one sodium dodecyl sulfate (SDS-based methods. Three drying methods for leaves samples were also evaluated including drying at room temperature (RT, in an oven at 40ºC (S40, and in a microwave oven (FMO. The DNA solutions obtained from different types of leaves samples using the five protocols were assessed in terms of cost, execution time, and quality and yield of extracted DNA. The commercial kit did not extract DNA with sufficient quantity or quality for successful PCR reactions. Among the classic methods, only the protocols of Dellaporta and of Khanuja yielded DNA extractions for all three types of foliar samples that resulted in successful PCR reactions and subsequent enzyme restriction assays. Based on the evaluated variables, the most appropriate DNA extraction method for Nectandra megapotamica (Spreng. Mez. was that of Dellaporta, regardless of the method used to dry the samples. The selected method has a relatively low cost and total execution time. Moreover, the quality and quantity of DNA extracted using this method was sufficient for DNA sequence amplification using PCR reactions and to get restriction fragments.

  10. Magnetic Resonance and Ultrasound Image Fusion Supported Transperineal Prostate Biopsy Using the Ginsburg Protocol: Technique, Learning Points, and Biopsy Results.

    Science.gov (United States)

    Hansen, Nienke; Patruno, Giulio; Wadhwa, Karan; Gaziev, Gabriele; Miano, Roberto; Barrett, Tristan; Gnanapragasam, Vincent; Doble, Andrew; Warren, Anne; Bratt, Ola; Kastner, Christof

    2016-08-01

    high, prostate biopsies may not be needed for all men with elevated prostate-specific antigen values and nonsuspicious mpMRI. We present our technique to sample (biopsy) the prostate by the transperineal route (the area between the scrotum and the anus) to detect prostate cancer using a fusion of magnetic resonance and ultrasound images to guide the sampling. Copyright © 2016 European Association of Urology. All rights reserved.

  11. The UK Biobank sample handling and storage protocol for the collection, processing and archiving of human blood and urine.

    Science.gov (United States)

    Elliott, Paul; Peakman, Tim C

    2008-04-01

    UK Biobank is a large prospective study in the UK to investigate the role of genetic factors, environmental exposures and lifestyle in the causes of major diseases of late and middle age. Extensive data and biological samples are being collected from 500,000 participants aged between 40 and 69 years. The biological samples that are collected and how they are processed and stored will have a major impact on the future scientific usefulness of the UK Biobank resource. The aim of the UK Biobank sample handling and storage protocol is to specify methods for the collection and storage of participant samples that give maximum scientific return within the available budget. Processing or storage methods that, as far as can be predicted, will preclude current or future assays have been avoided. The protocol was developed through a review of the literature on sample handling and processing, wide consultation within the academic community and peer review. Protocol development addressed which samples should be collected, how and when they should be processed and how the processed samples should be stored to ensure their long-term integrity. The recommended protocol was extensively tested in a series of validation studies. UK Biobank collects about 45 ml blood and 9 ml of urine with minimal local processing from each participant using the vacutainer system. A variety of preservatives, anti-coagulants and clot accelerators is used appropriate to the expected end use of the samples. Collection of other material (hair, nails, saliva and faeces) was also considered but rejected for the full cohort. Blood and urine samples from participants are transported overnight by commercial courier to a central laboratory where they are processed and aliquots of urine, plasma, serum, white cells and red cells stored in ultra-low temperature archives. Aliquots of whole blood are also stored for potential future production of immortalized cell lines. A standard panel of haematology assays is

  12. Solid Phase Microextraction and Related Techniques for Drugs in Biological Samples

    OpenAIRE

    Moein, Mohammad Mahdi; Said, Rana; Bassyouni, Fatma; Abdel-Rehim, Mohamed

    2014-01-01

    In drug discovery and development, the quantification of drugs in biological samples is an important task for the determination of the physiological performance of the investigated drugs. After sampling, the next step in the analytical process is sample preparation. Because of the low concentration levels of drug in plasma and the variety of the metabolites, the selected extraction technique should be virtually exhaustive. Recent developments of sample handling techniques are directed, from o...

  13. Evaluation of sampling, cookery, and shear force protocols for objective evaluation of lamb longissimus tenderness.

    Science.gov (United States)

    Shackelford, S D; Wheeler, T L; Koohmaraie, M

    2004-03-01

    Experiments were conducted to compare the effects of two cookery methods, two shear force procedures, and sampling location within non-callipyge and callipyge lamb LM on the magnitude, variance, and repeatability of LM shear force data. In Exp. 1, 15 non-callipyge and 15 callipyge carcasses were sampled, and Warner-Bratzler shear force (WBSF) was determined for both sides of each carcass at three locations along the length (anterior to posterior) of the LM, whereas slice shear force (SSF) was determined for both sides of each carcass at only one location. For approximately half the carcasses within each genotype, LM chops were cooked for a constant amount of time using a belt grill, and chops of the remaining carcasses were cooked to a constant endpoint temperature using open-hearth electric broilers. Regardless of cooking method and sampling location, repeatability estimates were at least 0.8 for LM WBSF and SSF. For WBSF, repeatability estimates were slightly higher at the anterior location (0.93 to 0.98) than the posterior location (0.88 to 0.90). The difference in repeatability between locations was probably a function of a greater level of variation in shear force at the anterior location. For callipyge LM, WBSF was higher (P lamb LM chops cooked with the belt grill using a larger number of animals (n = 87). In Exp. 2, LM chops were obtained from matching locations of both sides of 44 non-callipyge and 43 callipyge carcasses. Chops were cooked with a belt grill and SSF was measured, and repeatability was estimated to be 0.95. Repeatable estimates of lamb LM tenderness can be achieved either by cooking to a constant endpoint temperature with electric broilers or cooking for a constant amount of time with a belt grill. Likewise, repeatable estimates of lamb LM tenderness can be achieved with WBSF or SSF. However, use of belt grill cookery and the SSF technique could decrease time requirements which would decrease research costs.

  14. One Sample, One Shot - Evaluation of sample preparation protocols for the mass spectrometric proteome analysis of human bile fluid without extensive fractionation.

    Science.gov (United States)

    Megger, Dominik A; Padden, Juliet; Rosowski, Kristin; Uszkoreit, Julian; Bracht, Thilo; Eisenacher, Martin; Gerges, Christian; Neuhaus, Horst; Schumacher, Brigitte; Schlaak, Jörg F; Sitek, Barbara

    2017-02-10

    The proteome analysis of bile fluid represents a promising strategy to identify biomarker candidates for various diseases of the hepatobiliary system. However, to obtain substantive results in biomarker discovery studies large patient cohorts necessarily need to be analyzed. Consequently, this would lead to an unmanageable number of samples to be analyzed if sample preparation protocols with extensive fractionation methods are applied. Hence, the performance of simple workflows allowing for "one sample, one shot" experiments have been evaluated in this study. In detail, sixteen different protocols implying modifications at the stages of desalting, delipidation, deglycosylation and tryptic digestion have been examined. Each method has been individually evaluated regarding various performance criteria and comparative analyses have been conducted to uncover possible complementarities. Here, the best performance in terms of proteome coverage has been assessed for a combination of acetone precipitation with in-gel digestion. Finally, a mapping of all obtained protein identifications with putative biomarkers for hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) revealed several proteins easily detectable in bile fluid. These results can build the basis for future studies with large and well-defined patient cohorts in a more disease-related context. Human bile fluid is a proximal body fluid and supposed to be a potential source of disease markers. However, due to its biochemical composition, the proteome analysis of bile fluid still represents a challenging task and is therefore mostly conducted using extensive fractionation procedures. This in turn leads to a high number of mass spectrometric measurements for one biological sample. Considering the fact that in order to overcome the biological variability a high number of biological samples needs to be analyzed in biomarker discovery studies, this leads to the dilemma of an unmanageable number of

  15. Protocol for collecting eDNA samples from streams [Version 2.3

    Science.gov (United States)

    K. J. Carim; T. Wilcox; M. K. Young; K. S. McKelvey; M. K. Schwartz

    2015-01-01

    Throughout the 2014 field season, we had over two dozen biologist throughout the western US collect over 300 samples for eDNA analysis with paired controls. Control samples were collected by filtering 0.5 L of distilled water. No samples had any evidence of field contamination. This method of sampling verifies the cleanliness of the field equipment, as well as the...

  16. A new sampling technique for surface exposure dating using a portable electric rock cutter

    Directory of Open Access Journals (Sweden)

    Yusuke Suganuma

    2012-07-01

    Full Text Available Surface exposure dating using in situ cosmogenic nuclides has contributed to our understanding of Earth-surface processes. The precision of the ages estimated by this method is affected by the sample geometry; therefore, high accuracy measurements of the thickness and shape of the rock sample (thickness and shape is crucial. However, it is sometimes diffi cult to meet these requirements by conventional sampling methods with a hammer and chisel. Here, we propose a new sampling technique using a portable electric rock cutter. This sampling technique is faster, produces more precisely shaped samples, and allows for a more precise age interpretation. A simple theoretical modeldemonstrates that the age error due to defective sample geometry increases as the total sample thickness increases, indicating the importance of precise sampling for surface exposure dating.

  17. Magnetic separation techniques in sample preparation for biological analysis: a review.

    Science.gov (United States)

    He, Jincan; Huang, Meiying; Wang, Dongmei; Zhang, Zhuomin; Li, Gongke

    2014-12-01

    Sample preparation is a fundamental and essential step in almost all the analytical procedures, especially for the analysis of complex samples like biological and environmental samples. In past decades, with advantages of superparamagnetic property, good biocompatibility and high binding capacity, functionalized magnetic materials have been widely applied in various processes of sample preparation for biological analysis. In this paper, the recent advancements of magnetic separation techniques based on magnetic materials in the field of sample preparation for biological analysis were reviewed. The strategy of magnetic separation techniques was summarized. The synthesis, stabilization and bio-functionalization of magnetic nanoparticles were reviewed in detail. Characterization of magnetic materials was also summarized. Moreover, the applications of magnetic separation techniques for the enrichment of protein, nucleic acid, cell, bioactive compound and immobilization of enzyme were described. Finally, the existed problems and possible trends of magnetic separation techniques for biological analysis in the future were proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Sample preparation techniques based on combustion reactions in closed vessels - A brief overview and recent applications

    International Nuclear Information System (INIS)

    Flores, Erico M.M.; Barin, Juliano S.; Mesko, Marcia F.; Knapp, Guenter

    2007-01-01

    In this review, a general discussion of sample preparation techniques based on combustion reactions in closed vessels is presented. Applications for several kinds of samples are described, taking into account the literature data reported in the last 25 years. The operational conditions as well as the main characteristics and drawbacks are discussed for bomb combustion, oxygen flask and microwave-induced combustion (MIC) techniques. Recent applications of MIC techniques are discussed with special concern for samples not well digested by conventional microwave-assisted wet digestion as, for example, coal and also for subsequent determination of halogens

  19. Fast filtration sampling protocol for mammalian suspension cells tailored for phosphometabolome profiling by capillary ion chromatography - tandem mass spectrometry.

    Science.gov (United States)

    Kvitvang, Hans F N; Bruheim, Per

    2015-08-15

    Capillary ion chromatography (capIC) is the premium separation technology for low molecular phosphometabolites and nucleotides in biological extracts. Removal of excessive amounts of salt during sample preparation stages is a prerequisite to enable high quality capIC separation in combination with reproducible and sensitive MS detection. Existing sampling protocols for mammalian cells used for GC-MS and LC-MS metabolic profiling can therefore not be directly applied to capIC separations. Here, the development of a fast filtration sampling protocol for mammalian suspension cells tailored for quantitative profiling of the phosphometabolome on capIC-MS/MS is presented. The whole procedure from sampling the culture to transfer of filter to quenching and extraction solution takes less than 10s. To prevent leakage it is critical that a low vacuum pressure is applied, and satisfactorily reproducibility was only obtained by usage of a vacuum pressure controlling device. A vacuum of 60mbar was optimal for filtration of multiple myeloma Jjn-3 cell cultures through 5μm polyvinylidene (PVDF) filters. A quick deionized water (DI-water) rinse step prior to extraction was tested, and significantly higher metabolite yields were obtained during capIC-MS/MS analyses in this extract compared to extracts prepared by saline and reduced saline (25%) washing steps only. In addition, chromatographic performance was dramatically improved. Thus, it was verified that a quick DI-water rinse is tolerated by the cells and can be included as the final stage during filtration. Over 30 metabolites were quantitated in JJN-3 cell extracts by using the optimized sampling protocol with subsequent capIC-MS/MS analysis, and up to 2 million cells can be used in a single filtration step for the chosen filter and vacuum pressure. The technical set-up is also highly advantageous for microbial metabolome filtration protocols after optimization of vacuum pressure and washing solutions, and the reduced salt

  20. An Authentication Protocol for Mobile IPTV Users Based on an RFID-USB Convergence Technique

    Science.gov (United States)

    Jeong, Yoon-Su; Kim, Yong-Tae

    With the growing trend towards convergence in broadcast and communications media, Internet Protocol television (IPTV) that delivers real-time multimedia content over diverse types of communications networks (e.g., broadband Internet, cable TV, and satellite TV) has become a mainstream technology. Authenticating mobile IPTV subscribers who are continuously on the move is a challenge. A complex authentication process often impairs conditional access security or service quality as increasing illegal users and delaying service. This paper proposes an RFID-USB authentication protocol, for mobile IPTV users, combined with USIM-based personalized authentication and lightweight authentication that utilizes the RFID-USB technology with an implanted agent module (called an "agent tag") which temporarily enhanced user status information. The proposed authentication protocol adopts a plug-and-play security agent module that is placed in both an RFID tag and an RFID-USB. The implanted security agents cooperate in such a way that multiple RFID tags are connected seamlessly to an RFID-USB.

  1. Methodological integrative review of the work sampling technique used in nursing workload research.

    Science.gov (United States)

    Blay, Nicole; Duffield, Christine M; Gallagher, Robyn; Roche, Michael

    2014-11-01

    To critically review the work sampling technique used in nursing workload research. Work sampling is a technique frequently used by researchers and managers to explore and measure nursing activities. However, work sampling methods used are diverse making comparisons of results between studies difficult. Methodological integrative review. Four electronic databases were systematically searched for peer-reviewed articles published between 2002-2012. Manual scanning of reference lists and Rich Site Summary feeds from contemporary nursing journals were other sources of data. Articles published in the English language between 2002-2012 reporting on research which used work sampling to examine nursing workload. Eighteen articles were reviewed. The review identified that the work sampling technique lacks a standardized approach, which may have an impact on the sharing or comparison of results. Specific areas needing a shared understanding included the training of observers and subjects who self-report, standardization of the techniques used to assess observer inter-rater reliability, sampling methods and reporting of outcomes. Work sampling is a technique that can be used to explore the many facets of nursing work. Standardized reporting measures would enable greater comparison between studies and contribute to knowledge more effectively. Author suggestions for the reporting of results may act as guidelines for researchers considering work sampling as a research method. © 2014 John Wiley & Sons Ltd.

  2. A line-based vegetation sampling technique and its application in ...

    African Journals Online (AJOL)

    percentage cover, density and intercept frequency) and also provides plant size distributions, yet requires no more sampling effort than the line-intercept method.. A field test of the three techniques in succulent karoo, showed that the discriminating ...

  3. Fabrication Techniques of Stretchable and Cloth Electroadhesion Samples for Implementation on Devices with Space Application

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this study is to determine materials and fabrication techniques for efficient space-rated electroadhesion (EA) samples. Liquid metals, including...

  4. Sampling phased array a new technique for signal processing and ultrasonic imaging

    OpenAIRE

    Bulavinov, A.; Joneit, D.; Kröning, M.; Bernus, L.; Dalichow, M.H.; Reddy, K.M.

    2006-01-01

    Different signal processing and image reconstruction techniques are applied in ultrasonic non-destructive material evaluation. In recent years, rapid development in the fields of microelectronics and computer engineering lead to wide application of phased array systems. A new phased array technique, called "Sampling Phased Array" has been developed in Fraunhofer Institute for non-destructive testing. It realizes unique approach of measurement and processing of ultrasonic signals. The sampling...

  5. What Do Lead and Copper Sampling Protocols Mean, and Which Is Right for You?

    Science.gov (United States)

    this presentation will provide a short review of the explicit and implicit concepts behind most of the currently-used regulatory and diagnostic sampling schemes for lead, such as: random daytime sampling; automated proportional sampler; 30 minute first draw stagnation; Sequential...

  6. An analytical protocol for the determination of total mercury concentrations in solid peat samples

    DEFF Research Database (Denmark)

    Roos-Barraclough, F; Givelet, N; Martinez-Cortizas, A

    2002-01-01

    Traditional peat sample preparation methods such as drying at high temperatures and milling may be unsuitable for Hg concentration determination in peats due to the possible presence of volatile Hg species, which could be lost during drying. Here, the effects of sample preparation and natural.......12 and 8.52 ng kg(-1) h(-1), respectively). Fertilising the peat slightly increased Hg loss (3.08 ng kg(-1) h(-1) in NPK-fertilised peat compared to 0.28 ng kg(-1) h(-1) in unfertilised peat, when averaged over all temperatures used). Homogenising samples by grinding in a machine also caused a loss of Hg....... A comparison of two Hg profiles from an Arctic peat core, measured in frozen samples and in air-dried samples, revealed that no Hg losses occurred upon air-drying. A comparison of Hg concentrations in several plant species that make up peat, showed that some species (Pinus mugo, Sphagnum recurvum...

  7. Standardization of proton-induced x-ray emission technique for analysis of thick samples

    Science.gov (United States)

    Ali, Shad; Zeb, Johar; Ahad, Abdul; Ahmad, Ishfaq; Haneef, M.; Akbar, Jehan

    2015-09-01

    This paper describes the standardization of the proton-induced x-ray emission (PIXE) technique for finding the elemental composition of thick samples. For the standardization, three different samples of standard reference materials (SRMs) were analyzed using this technique and the data were compared with the already known data of these certified SRMs. These samples were selected in order to cover the maximum range of elements in the periodic table. Each sample was irradiated for three different values of collected beam charges at three different times. A proton beam of 2.57 MeV obtained using 5UDH-II Pelletron accelerator was used for excitation of x-rays from the sample. The acquired experimental data were analyzed using the GUPIXWIN software. The results show that the SRM data and the data obtained using the PIXE technique are in good agreement.

  8. Cone penetrometer tests and HydroPunch sampling: A screening technique for plume definition

    International Nuclear Information System (INIS)

    Smolley, M.; Kappmeyer, J.C.

    1991-01-01

    Cone penetrometer tests and HydroPunch sampling were used to define the extent of volatile organic compounds in ground water. The investigation indicated that the combination of the these techniques is effective for obtaining ground water samples for preliminary plume definition. HydroPunch samples can be collected in unconsolidated sediments and the analytical results obtained from these samples are comparable to those obtained from adjacent monitoring wells. This sampling method is a rapid and cost-effective screening technique for characterizing the extent of contaminant plumes in soft sediment environments. Use of this screening technique allowed monitoring wells to be located at the plume boundary, thereby reducing the number of wells installed and the overall cost of the plume definition program

  9. Demonstrating Reliable High Level Waste Slurry Sampling Techniques to Support Hanford Waste Processing

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Steven E.

    2013-11-11

    The Hanford Tank Operations Contractor (TOC) and the Hanford Waste Treatment and Immobilization Plant (WTP) contractor are both engaged in demonstrating mixing, sampling, and transfer system capability using simulated Hanford High-Level Waste (HL W) formulations. This work represents one of the remaining technical issues with the high-level waste treatment mission at Hanford. The TOC must demonstrate the ability to adequately mix and sample high-level waste feed to meet the WTP Waste Acceptance Criteria and Data Quality Objectives. The sampling method employed must support both TOC and WTP requirements. To facilitate information transfer between the two facilities the mixing and sampling demonstrations are led by the One System Integrated Project Team. The One System team, Waste Feed Delivery Mixing and Sampling Program, has developed a full scale sampling loop to demonstrate sampler capability. This paper discusses the full scale sampling loops ability to meet precision and accuracy requirements, including lessons learned during testing. Results of the testing showed that the Isolok(R) sampler chosen for implementation provides precise, repeatable results. The Isolok(R) sampler accuracy as tested did not meet test success criteria. Review of test data and the test platform following testing by a sampling expert identified several issues regarding the sampler used to provide reference material used to judge the Isolok's accuracy. Recommendations were made to obtain new data to evaluate the sampler's accuracy utilizing a reference sampler that follows good sampling protocol.

  10. Demonstrating Reliable High Level Waste Slurry Sampling Techniques to Support Hanford Waste Processing

    International Nuclear Information System (INIS)

    Kelly, Steven E.

    2013-01-01

    The Hanford Tank Operations Contractor (TOC) and the Hanford Waste Treatment and Immobilization Plant (WTP) contractor are both engaged in demonstrating mixing, sampling, and transfer system capability using simulated Hanford High-Level Waste (HL W) formulations. This work represents one of the remaining technical issues with the high-level waste treatment mission at Hanford. The TOC must demonstrate the ability to adequately mix and sample high-level waste feed to meet the WTP Waste Acceptance Criteria and Data Quality Objectives. The sampling method employed must support both TOC and WTP requirements. To facilitate information transfer between the two facilities the mixing and sampling demonstrations are led by the One System Integrated Project Team. The One System team, Waste Feed Delivery Mixing and Sampling Program, has developed a full scale sampling loop to demonstrate sampler capability. This paper discusses the full scale sampling loops ability to meet precision and accuracy requirements, including lessons learned during testing. Results of the testing showed that the Isolok(R) sampler chosen for implementation provides precise, repeatable results. The Isolok(R) sampler accuracy as tested did not meet test success criteria. Review of test data and the test platform following testing by a sampling expert identified several issues regarding the sampler used to provide reference material used to judge the Isolok's accuracy. Recommendations were made to obtain new data to evaluate the sampler's accuracy utilizing a reference sampler that follows good sampling protocol

  11. Optimized IMAC-IMAC protocol for phosphopeptide recovery from complex biological samples

    DEFF Research Database (Denmark)

    Ye, Juanying; Zhang, Xumin; Young, Clifford

    2010-01-01

    using Fe(III)-NTA IMAC resin and it proved to be highly selective in the phosphopeptide enrichment of a highly diluted standard sample (1:1000) prior to MALDI MS analysis. We also observed that a higher iron purity led to an increased IMAC enrichment efficiency. The optimized method was then adapted...... to phosphoproteome analyses of cell lysates of high protein complexity. From either 20 microg of mouse sample or 50 microg of Drosophila melanogaster sample, more than 1000 phosphorylation sites were identified in each study using IMAC-IMAC and LC-MS/MS. We demonstrate efficient separation of multiply phosphorylated...... characterization of phosphoproteins in functional phosphoproteomics research projects....

  12. Sample preparation techniques in trace element analysis by X-ray emission spectroscopy

    International Nuclear Information System (INIS)

    Valkovic, V.

    1983-11-01

    The report, written under a research contract with the IAEA, contains a detailed presentation of the most difficult problem encountered in the trace element analysis by methods of the X-ray emission spectroscopy, namely the sample preparation techniques. The following items are covered. Sampling - with specific consideration of aerosols, water, soil, biological materials, petroleum and its products, storage of samples and their handling. Pretreatment of samples - preconcentration, ashing, solvent extraction, ion exchange and electrodeposition. Sample preparations for PIXE - analysis - backings, target uniformity and homogeneity, effects of irradiation, internal standards and specific examples of preparation (aqueous, biological, blood serum and solid samples). Sample preparations for radioactive sources or tube excitation - with specific examples (water, liquid and solid samples, soil, geological, plants and tissue samples). Finally, the problem of standards and reference materials, as well as that of interlaboratory comparisons, is discussed

  13. Mantle biopsy: a technique for nondestructive tissue-sampling of freshwater mussels

    Science.gov (United States)

    David J. Berg; Wendell R. Haag; Sheldon I. Guttman; James B. Sickel

    1995-01-01

    Mantle biopsy is a means of obtaining tissue samples for genetic, physiological, and contaminant studies of bivalves; but the effects of this biopsy on survival have not been determined. We describe a simple technique for obtaining such samples from unionacean bivalves and how we compared survival among biopsied and control organisms in field experiments. Survival was...

  14. RF Sub-sampling Receiver Architecture based on Milieu Adapting Techniques

    DEFF Research Database (Denmark)

    Behjou, Nastaran; Larsen, Torben; Jensen, Ole Kiel

    2012-01-01

    A novel sub-sampling based architecture is proposed which has the ability of reducing the problem of image distortion and improving the signal to noise ratio significantly. The technique is based on sensing the environment and adapting the sampling rate of the receiver to the best possible...

  15. Thermophilic Campylobacter spp. in turkey samples: evaluation of two automated enzyme immunoassays and conventional microbiological techniques

    DEFF Research Database (Denmark)

    Borck, Birgitte; Stryhn, H.; Ersboll, A.K.

    2002-01-01

    Aims: To determine the sensitivity and specificity of two automated enzyme immunoassays (EIA), EiaFoss and Minividas, and a conventional microbiological culture technique for detecting thermophilic Campylobacter spp. in turkey samples. Methods and Results: A total of 286 samples (faecal, meat...

  16. Laboratory techniques for safe encapsulation of α-emitting powder samples

    International Nuclear Information System (INIS)

    Chamberlain, H.E.; Pottinger, J.S.

    1984-01-01

    Plutonium oxide powder samples can be encapsulated in thin plastic film to prevent spread of contamination in counting and X-ray diffraction equipment. The film has to be thin enough to transmit X-rays and α-particles. Techniques are described for the wrapping process and the precautions necessary to keep the sample processing line free of significant contamination. (author)

  17. A fully blanketed early B star LTE model atmosphere using an opacity sampling technique

    International Nuclear Information System (INIS)

    Phillips, A.P.; Wright, S.L.

    1980-01-01

    A fully blanketed LTE model of a stellar atmosphere with Tsub(e) = 21914 K (thetasub(e) = 0.23), log g = 4 is presented. The model includes an explicit representation of the opacity due to the strongest lines, and uses a statistical opacity sampling technique to represent the weaker line opacity. The sampling technique is subjected to several tests and the model is compared with an atmosphere calculated using the line-distribution function method. The limitations of the distribution function method and the particular opacity sampling method used here are discussed in the light of the results obtained. (author)

  18. Prompt Gamma Activation Analysis (PGAA): Technique of choice for nondestructive bulk analysis of returned comet samples

    International Nuclear Information System (INIS)

    Lindstrom, D.J.; Lindstrom, R.M.

    1989-01-01

    Prompt gamma activation analysis (PGAA) is a well-developed analytical technique. The technique involves irradiation of samples in an external neutron beam from a nuclear reactor, with simultaneous counting of gamma rays produced in the sample by neutron capture. Capture of neutrons leads to excited nuclei which decay immediately with the emission of energetic gamma rays to the ground state. PGAA has several advantages over other techniques for the analysis of cometary materials: (1) It is nondestructive; (2) It can be used to determine abundances of a wide variety of elements, including most major and minor elements (Na, Mg, Al, Si, P, K, Ca, Ti, Cr, Mn, Fe, Co, Ni), volatiles (H, C, N, F, Cl, S), and some trace elements (those with high neutron capture cross sections, including B, Cd, Nd, Sm, and Gd); and (3) It is a true bulk analysis technique. Recent developments should improve the technique's sensitivity and accuracy considerably

  19. Can groundwater sampling techniques used in monitoring wells influence methane concentrations and isotopes?

    Science.gov (United States)

    Rivard, Christine; Bordeleau, Geneviève; Lavoie, Denis; Lefebvre, René; Malet, Xavier

    2018-03-06

    Methane concentrations and isotopic composition in groundwater are the focus of a growing number of studies. However, concerns are often expressed regarding the integrity of samples, as methane is very volatile and may partially exsolve during sample lifting in the well and transfer to sampling containers. While issues concerning bottle-filling techniques have already been documented, this paper documents a comparison of methane concentration and isotopic composition obtained with three devices commonly used to retrieve water samples from dedicated observation wells. This work lies within the framework of a larger project carried out in the Saint-Édouard area (southern Québec, Canada), whose objective was to assess the risk to shallow groundwater quality related to potential shale gas exploitation. The selected sampling devices, which were tested on ten wells during three sampling campaigns, consist of an impeller pump, a bladder pump, and disposable sampling bags (HydraSleeve). The sampling bags were used both before and after pumping, to verify the appropriateness of a no-purge approach, compared to the low-flow approach involving pumping until stabilization of field physicochemical parameters. Results show that methane concentrations obtained with the selected sampling techniques are usually similar and that there is no systematic bias related to a specific technique. Nonetheless, concentrations can sometimes vary quite significantly (up to 3.5 times) for a given well and sampling event. Methane isotopic composition obtained with all sampling techniques is very similar, except in some cases where sampling bags were used before pumping (no-purge approach), in wells where multiple groundwater sources enter the borehole.

  20. Long-term monitoring of the Danube river-Sampling techniques, radionuclide metrology and radioecological assessment

    International Nuclear Information System (INIS)

    Maringer, F.J.; Gruber, V.; Hrachowitz, M.; Baumgartner, A.; Weilner, S.; Seidel, C.

    2009-01-01

    Sampling techniques and radiometric methods, developed and applied in a comprehensive radioecological study of the Danube River are presented. Results and radiometric data of sediment samples, collected by sediment traps in Austria and additionally by grab sampling in the Danube during research cruises between Germany and the delta (Black sea) are shown and discussed. Goal of the investigation is the protection of public and environment, especially the sustainable use and conservation of human freshwater resources against harmful radioactive exposure.

  1. Comparison between correlated sampling and the perturbation technique of MCNP5 for fixed-source problems

    International Nuclear Information System (INIS)

    He Tao; Su Bingjing

    2011-01-01

    Highlights: → The performance of the MCNP differential operator perturbation technique is compared with that of the MCNP correlated sampling method for three types of fixed-source problems. → In terms of precision, the MCNP perturbation technique outperforms correlated sampling for one type of problem but performs comparably with or even under-performs correlated sampling for the other two types of problems. → In terms of accuracy, the MCNP perturbation calculations may predict inaccurate results for some of the test problems. However, the accuracy can be improved if the midpoint correction technique is used. - Abstract: Correlated sampling and the differential operator perturbation technique are two methods that enable MCNP (Monte Carlo N-Particle) to simulate small response change between an original system and a perturbed system. In this work the performance of the MCNP differential operator perturbation technique is compared with that of the MCNP correlated sampling method for three types of fixed-source problems. In terms of precision of predicted response changes, the MCNP perturbation technique outperforms correlated sampling for the problem involving variation of nuclide concentrations in the same direction but performs comparably with or even underperforms correlated sampling for the other two types of problems that involve void or variation of nuclide concentrations in opposite directions. In terms of accuracy, the MCNP differential operator perturbation calculations may predict inaccurate results that deviate from the benchmarks well beyond their uncertainty ranges for some of the test problems. However, the accuracy of the MCNP differential operator perturbation can be improved if the midpoint correction technique is used.

  2. The Work-It Study for people with arthritis: Study protocol and baseline sample characteristics.

    Science.gov (United States)

    Keysor, Julie J; AlHeresh, Rawan; Vaughan, Molly; LaValley, Michael P; Allaire, Saralynn

    2016-06-14

    People with arthritis are at risk of work disability. Job accommodation and educational programs delivered before imminent work loss can minimize work disability, yet are not currently being widely implemented. The Work-It Study is a randomized controlled trial testing the efficacy of a problem solving program delivered by physical and occupational therapy practitioners to prevent work loss over a two-year period among people with arthritis and rheumatological conditions. The purpose of this paper is to describe the protocol of the randomized controlled trial, and describe the baseline characteristics of the subjects and their work outcomes. 287 participants were recruited from the Boston area in Massachusetts, USA. Eligible participants were aged between 21-65, self-reported a physicians' diagnosis of arthritis, rheumatic condition, or chronic back pain, reported a concern about working now or in the near future due to your health, worked at least 15 hours a week, had plans to continue working, and worked or lived in Massachusetts. Subjects were recruited through community sources and rheumatology offices. Participants in the experimental group received a structured interview and an education and resource packet, while participants in the control received the resource packet only. The baseline characteristics and work related outcomes of the participants were analyzed. To our knowledge, the Work-It Study is the largest and most diverse randomized controlled trial to date aiming to identify and problem solve work-related barriers, promote advocacy, and foster work disability knowledge among people with chronic disabling musculoskeletal conditions. Despite advances in medical management of arthritis and other rheumatological and musculoskeletal conditions, many people still have concerns about their ability to remain employed and are seeking strategies to help them sustain employment.

  3. Elemental analyses of goundwater: demonstrated advantage of low-flow sampling and trace-metal clean techniques over standard techniques

    Science.gov (United States)

    Creasey, C. L.; Flegal, A. R.

    The combined use of both (1) low-flow purging and sampling and (2) trace-metal clean techniques provides more representative measurements of trace-element concentrations in groundwater than results derived with standard techniques. The use of low-flow purging and sampling provides relatively undisturbed groundwater samples that are more representative of in situ conditions, and the use of trace-element clean techniques limits the inadvertent introduction of contaminants during sampling, storage, and analysis. When these techniques are applied, resultant trace-element concentrations are likely to be markedly lower than results based on standard sampling techniques. In a comparison of data derived from contaminated and control groundwater wells at a site in California, USA, trace-element concentrations from this study were 2-1000 times lower than those determined by the conventional techniques used in sampling of the same wells prior to (5months) and subsequent to (1month) the collections for this study. Specifically, the cadmium and chromium concentrations derived using standard sampling techniques exceed the California Maximum Contaminant Levels (MCL), whereas in this investigation concentrations of both of those elements are substantially below their MCLs. Consequently, the combined use of low-flow and trace-metal clean techniques may preclude erroneous reports of trace-element contamination in groundwater. Résumé L'utilisation simultanée de la purge et de l'échantillonnage à faible débit et des techniques sans traces de métaux permet d'obtenir des mesures de concentrations en éléments en traces dans les eaux souterraines plus représentatives que les résultats fournis par les techniques classiques. L'utilisation de la purge et de l'échantillonnage à faible débit donne des échantillons d'eau souterraine relativement peu perturbés qui sont plus représentatifs des conditions in situ, et le recours aux techniques sans éléments en traces limite l

  4. A Comparative Analysis of Transmission Control Protocol Improvement Techniques over Space-Based Transmission Media

    National Research Council Canada - National Science Library

    Lawson, Joseph M

    2006-01-01

    ... justification for the implementation of a given enhancement technique. The research questions were answered through model and simulation of a satellite transmission system via a Linux-based network topology...

  5. A Comparative Analysis of Transmission Control Protocol Improvement Techniques over Space-Based Transmission Media

    National Research Council Canada - National Science Library

    Lawson, Joseph M

    2006-01-01

    The purpose of this study was to assess the throughput improvement afforded by the various TCP optimization techniques, with respect to a simulated geosynchronous satellite system, to provide a cost...

  6. USDA Forest Service national protocols for sampling air pollution-sensitive waters

    Science.gov (United States)

    T. J. Sullivan

    2012-01-01

    The first step in designing a surface water sampling program is identifying one or more problems or questions that require information on water quality. Common water quality problems include nutrient enrichment (from a variety of causes), effects of atmospheric deposition (acidification, eutrophication, toxicity), and effects of major disturbances such as fire or pest...

  7. Guidance Document: Surface Soils Sampling for Munitions Residues in Military Live Fire Training Ranges: Canadian Protocol

    Science.gov (United States)

    2012-12-01

    nitrocellulose fibres. For samples larger than 500 g, multiple batches are used and the final fine powder (which looks like flour ) is mixed thoroughly on a...Clausen, J., Hewitt, A.D., Brochu, S., Dubé, P., Lewis, J., Ranney, T., Faucher, D., Gagnon, A., Stark, J., Brousseau, P., Price , C., Lambert, D

  8. Protocol for chromosome-specific probe construction using PRINS, micromanipulation and DOP-PCR techniques

    Directory of Open Access Journals (Sweden)

    PAULO Z. PASSAMANI

    2017-12-01

    Full Text Available ABSTRACT Chromosome-specific probes have been widely used in molecular cytogenetics, being obtained with different methods. In this study, a reproducible protocol for construction of chromosome-specific probes is proposed which associates in situ amplification (PRINS, micromanipulation and degenerate oligonucleotide-primed PCR (DOP-PCR. Human lymphocyte cultures were used to obtain metaphases from male and female individuals. The chromosomes were amplified via PRINS, and subcentromeric fragments of the X chromosome were microdissected using microneedles coupled to a phase contrast microscope. The fragments were amplified by DOP-PCR and labeled with tetramethyl-rhodamine-5-dUTP. The probes were used in fluorescent in situ hybridization (FISH procedure to highlight these specific regions in the metaphases. The results show one fluorescent red spot in male and two in female X chromosomes and interphase nuclei.

  9. Comparative of three sampling protocols for water quality assessment using macro invertebrates; Comparacion de tres protocolos de muestreo de macroinvertebrados para determinar la calidad del agua

    Energy Technology Data Exchange (ETDEWEB)

    Puertolas Domenech, L.; Rieradevall Sant, M.; Prat Fornells, N.

    2007-07-01

    The implementation of the Water Framework directive (WFD, Directive 2000/60/CE) requires the establishment of standardized sampling protocols for the assessment of benthic fauna. In this paper, a comparative study of several sampling protocols that are used currently in Spain and Europe (AQEM, EPA and Guadalmed) has been carried out. Evaluating the three protocols with a list of 12 criteria, Guadalmed fits better to the most of them. therefore it appears as an efficient tool in the determination of Ecological Status. (Author)

  10. The electron transport problem sampling by Monte Carlo individual collision technique

    International Nuclear Information System (INIS)

    Androsenko, P.A.; Belousov, V.I.

    2005-01-01

    The problem of electron transport is of most interest in all fields of the modern science. To solve this problem the Monte Carlo sampling has to be used. The electron transport is characterized by a large number of individual interactions. To simulate electron transport the 'condensed history' technique may be used where a large number of collisions are grouped into a single step to be sampled randomly. Another kind of Monte Carlo sampling is the individual collision technique. In comparison with condensed history technique researcher has the incontestable advantages. For example one does not need to give parameters altered by condensed history technique like upper limit for electron energy, resolution, number of sub-steps etc. Also the condensed history technique may lose some very important tracks of electrons because of its limited nature by step parameters of particle movement and due to weakness of algorithms for example energy indexing algorithm. There are no these disadvantages in the individual collision technique. This report presents some sampling algorithms of new version BRAND code where above mentioned technique is used. All information on electrons was taken from Endf-6 files. They are the important part of BRAND. These files have not been processed but directly taken from electron information source. Four kinds of interaction like the elastic interaction, the Bremsstrahlung, the atomic excitation and the atomic electro-ionization were considered. In this report some results of sampling are presented after comparison with analogs. For example the endovascular radiotherapy problem (P2) of QUADOS2002 was presented in comparison with another techniques that are usually used. (authors)

  11. The electron transport problem sampling by Monte Carlo individual collision technique

    Energy Technology Data Exchange (ETDEWEB)

    Androsenko, P.A.; Belousov, V.I. [Obninsk State Technical Univ. of Nuclear Power Engineering, Kaluga region (Russian Federation)

    2005-07-01

    The problem of electron transport is of most interest in all fields of the modern science. To solve this problem the Monte Carlo sampling has to be used. The electron transport is characterized by a large number of individual interactions. To simulate electron transport the 'condensed history' technique may be used where a large number of collisions are grouped into a single step to be sampled randomly. Another kind of Monte Carlo sampling is the individual collision technique. In comparison with condensed history technique researcher has the incontestable advantages. For example one does not need to give parameters altered by condensed history technique like upper limit for electron energy, resolution, number of sub-steps etc. Also the condensed history technique may lose some very important tracks of electrons because of its limited nature by step parameters of particle movement and due to weakness of algorithms for example energy indexing algorithm. There are no these disadvantages in the individual collision technique. This report presents some sampling algorithms of new version BRAND code where above mentioned technique is used. All information on electrons was taken from Endf-6 files. They are the important part of BRAND. These files have not been processed but directly taken from electron information source. Four kinds of interaction like the elastic interaction, the Bremsstrahlung, the atomic excitation and the atomic electro-ionization were considered. In this report some results of sampling are presented after comparison with analogs. For example the endovascular radiotherapy problem (P2) of QUADOS2002 was presented in comparison with another techniques that are usually used. (authors)

  12. LVQ-SMOTE - Learning Vector Quantization based Synthetic Minority Over-sampling Technique for biomedical data.

    Science.gov (United States)

    Nakamura, Munehiro; Kajiwara, Yusuke; Otsuka, Atsushi; Kimura, Haruhiko

    2013-10-02

    Over-sampling methods based on Synthetic Minority Over-sampling Technique (SMOTE) have been proposed for classification problems of imbalanced biomedical data. However, the existing over-sampling methods achieve slightly better or sometimes worse result than the simplest SMOTE. In order to improve the effectiveness of SMOTE, this paper presents a novel over-sampling method using codebooks obtained by the learning vector quantization. In general, even when an existing SMOTE applied to a biomedical dataset, its empty feature space is still so huge that most classification algorithms would not perform well on estimating borderlines between classes. To tackle this problem, our over-sampling method generates synthetic samples which occupy more feature space than the other SMOTE algorithms. Briefly saying, our over-sampling method enables to generate useful synthetic samples by referring to actual samples taken from real-world datasets. Experiments on eight real-world imbalanced datasets demonstrate that our proposed over-sampling method performs better than the simplest SMOTE on four of five standard classification algorithms. Moreover, it is seen that the performance of our method increases if the latest SMOTE called MWMOTE is used in our algorithm. Experiments on datasets for β-turn types prediction show some important patterns that have not been seen in previous analyses. The proposed over-sampling method generates useful synthetic samples for the classification of imbalanced biomedical data. Besides, the proposed over-sampling method is basically compatible with basic classification algorithms and the existing over-sampling methods.

  13. Modified emission-transmission method for determining trace elements in solid samples using the XRF techniques

    International Nuclear Information System (INIS)

    Poblete, V.; Alvarez, M.; Hermosilla, M.

    2000-01-01

    This is a study of an analysis of trace elements in medium thick solid samples, by the modified transmission emission method, using the energy dispersion X-ray fluorescence technique (EDXRF). The effects of absorption and reinforcement are the main disadvantages of the EDXRF technique for the quantitative analysis of bigger elements and trace elements in solid samples. The implementation of this method and its application to a variety of samples was carried out using an infinitely thick multi-element white sample that calculates the correction factors by absorbing all the analytes in the sample. The discontinuities in the masic absorption coefficients versus energies association for each element, with medium thick and homogenous samples, are analyzed and corrected. A thorough analysis of the different theoretical and test variables are proven by using real samples, including certified material with known concentration. The simplicity of the calculation method and the results obtained show the method's major precision, with possibilities for the non-destructive routine analysis of different solid samples, using the EDXRF technique (author)

  14. X-ray spectrometry and X-ray microtomography techniques for soil and geological samples analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Dziadowicz, M.; Kopeć, E. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Majewska, U. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Mazurek, M.; Pajek, M.; Sobisz, M.; Stabrawa, I. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Wudarczyk-Moćko, J. [Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Góźdź, S. [Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Institute of Public Health, Jan Kochanowski University, IX Wieków Kielc 19, 25-317 Kielce (Poland)

    2015-12-01

    A particular subject of X-ray fluorescence analysis is its application in studies of the multielemental sample of composition in a wide range of concentrations, samples with different matrices, also inhomogeneous ones and those characterized with different grain size. Typical examples of these kinds of samples are soil or geological samples for which XRF elemental analysis may be difficult due to XRF disturbing effects. In this paper the WDXRF technique was applied in elemental analysis concerning different soil and geological samples (therapeutic mud, floral soil, brown soil, sandy soil, calcium aluminum cement). The sample morphology was analyzed using X-ray microtomography technique. The paper discusses the differences between the composition of samples, the influence of procedures with respect to the preparation of samples as regards their morphology and, finally, a quantitative analysis. The results of the studies were statistically tested (one-way ANOVA and correlation coefficients). For lead concentration determination in samples of sandy soil and cement-like matrix, the WDXRF spectrometer calibration was performed. The elemental analysis of the samples was complemented with knowledge of chemical composition obtained by X-ray powder diffraction.

  15. X-ray spectrometry and X-ray microtomography techniques for soil and geological samples analysis

    International Nuclear Information System (INIS)

    Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J.; Dziadowicz, M.; Kopeć, E.; Majewska, U.; Mazurek, M.; Pajek, M.; Sobisz, M.; Stabrawa, I.; Wudarczyk-Moćko, J.; Góźdź, S.

    2015-01-01

    A particular subject of X-ray fluorescence analysis is its application in studies of the multielemental sample of composition in a wide range of concentrations, samples with different matrices, also inhomogeneous ones and those characterized with different grain size. Typical examples of these kinds of samples are soil or geological samples for which XRF elemental analysis may be difficult due to XRF disturbing effects. In this paper the WDXRF technique was applied in elemental analysis concerning different soil and geological samples (therapeutic mud, floral soil, brown soil, sandy soil, calcium aluminum cement). The sample morphology was analyzed using X-ray microtomography technique. The paper discusses the differences between the composition of samples, the influence of procedures with respect to the preparation of samples as regards their morphology and, finally, a quantitative analysis. The results of the studies were statistically tested (one-way ANOVA and correlation coefficients). For lead concentration determination in samples of sandy soil and cement-like matrix, the WDXRF spectrometer calibration was performed. The elemental analysis of the samples was complemented with knowledge of chemical composition obtained by X-ray powder diffraction.

  16. [Sampling and measurement methods of the protocol design of the China Nine-Province Survey for blindness, visual impairment and cataract surgery].

    Science.gov (United States)

    Zhao, Jia-liang; Wang, Yu; Gao, Xue-cheng; Ellwein, Leon B; Liu, Hu

    2011-09-01

    To design the protocol of the China nine-province survey for blindness, visual impairment and cataract surgery to evaluate the prevalence and main causes of blindness and visual impairment, and the prevalence and outcomes of the cataract surgery. The protocol design was began after accepting the task for the national survey for blindness, visual impairment and cataract surgery from the Department of Medicine, Ministry of Health, China, in November, 2005. The protocol in Beijing Shunyi Eye Study in 1996 and Guangdong Doumen County Eye Study in 1997, both supported by World Health Organization, was taken as the basis for the protocol design. The relative experts were invited to discuss and prove the draft protocol. An international advisor committee was established to examine and approve the draft protocol. Finally, the survey protocol was checked and approved by the Department of Medicine, Ministry of Health, China and Prevention Program of Blindness and Deafness, WHO. The survey protocol was designed according to the characteristics and the scale of the survey. The contents of the protocol included determination of target population and survey sites, calculation of the sample size, design of the random sampling, composition and organization of the survey teams, determination of the examinee, the flowchart of the field work, survey items and methods, diagnostic criteria of blindness and moderate and sever visual impairment, the measures of the quality control, the methods of the data management. The designed protocol became the standard and practical protocol for the survey to evaluate the prevalence and main causes of blindness and visual impairment, and the prevalence and outcomes of the cataract surgery.

  17. Improved importance sampling technique for efficient simulation of digital communication systems

    Science.gov (United States)

    Lu, Dingqing; Yao, Kung

    1988-01-01

    A new, improved importance sampling (IIS) approach to simulation is considered. Some basic concepts of IS are introduced, and detailed evolutions of simulation estimation variances for Monte Carlo (MC) and IS simulations are given. The general results obtained from these evolutions are applied to the specific previously known conventional importance sampling (CIS) technique and the new IIS technique. The derivation for a linear system with no signal random memory is considered in some detail. For the CIS technique, the optimum input scaling parameter is found, while for the IIS technique, the optimum translation parameter is found. The results are generalized to a linear system with memory and signals. Specific numerical and simulation results are given which show the advantages of CIS over MC and IIS over CIS for simulations of digital communications systems.

  18. Symbol synchronization and sampling frequency synchronization techniques in real-time DDO-OFDM systems

    Science.gov (United States)

    Chen, Ming; He, Jing; Cao, Zizheng; Tang, Jin; Chen, Lin; Wu, Xian

    2014-09-01

    In this paper, we propose and experimentally demonstrate a symbol synchronization and sampling frequency synchronization techniques in real-time direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) system, over 100-km standard single mode fiber (SSMF) using a cost-effective directly modulated distributed feedback (DFB) laser. The experiment results show that the proposed symbol synchronization based on training sequence (TS) has a low complexity and high accuracy even at a sampling frequency offset (SFO) of 5000-ppm. Meanwhile, the proposed pilot-assisted sampling frequency synchronization between digital-to-analog converter (DAC) and analog-to-digital converter (ADC) is capable of estimating SFOs with an accuracy of technique can also compensate SFO effects within a small residual SFO caused by deviation of SFO estimation and low-precision or unstable clock source. The two synchronization techniques are suitable for high-speed DDO-OFDM transmission systems.

  19. A technique for extracting blood samples from mice in fire toxicity tests

    Science.gov (United States)

    Bucci, T. J.; Hilado, C. J.; Lopez, M. T.

    1976-01-01

    The extraction of adequate blood samples from moribund and dead mice has been a problem because of the small quantity of blood in each animal and the short time available between the animals' death and coagulation of the blood. These difficulties are particularly critical in fire toxicity tests because removal of the test animals while observing proper safety precautions for personnel is time-consuming. Techniques for extracting blood samples from mice were evaluated, and a technique was developed to obtain up to 0.8 ml of blood from a single mouse after death. The technique involves rapid exposure and cutting of the posterior vena cava and accumulation of blood in the peritoneal space. Blood samples of 0.5 ml or more from individual mice have been consistently obtained as much as 16 minutes after apparent death. Results of carboxyhemoglobin analyses of blood appeared reproducible and consistent with carbon monoxide concentrations in the exposure chamber.

  20. Investigations of the post-IR IRSL protocol applied to single K-feldspar grains from fluvial sediment samples

    International Nuclear Information System (INIS)

    Nian, Xiaomei; Bailey, Richard M.; Zhou, Liping

    2012-01-01

    The post-IR IRSL protocol with single K-feldspar grains was applied to three samples taken from a fluvial sedimentary sequence at the archaeological site of the Dali Man, Shaanxi Province, China. K-feldspar coarse grains were extracted for measurement. Approximately 30–40% of the grains were sufficiently bright to measure, and after application of rejection criteria based on signal strength, recuperation, recycling ratio and saturation dose, ∼10–15% of the grains were used for D e calculation. The relationship of signal decay rate and form of D e (t) with the recovery dose were investigated. The dose recovery ratios of the samples after initial bleaching with the four different light sources were within uncertainties of unity. No anomalous fading was observed. The over-dispersion of the recovered dose and D e values were similar, suggesting neither incomplete resetting of the post-IR IRSL signals nor spatially heterogeneous dose rates significantly affected the natural dose estimates. The values of D e obtained with the single K-feldspar grain post-IR IRSL protocol were in the range ∼400–490 Gy. Combining all of the measured single-grain signals for each of the individual samples (into a ‘synthetic single aliquot’) increased the D e estimates to the range ∼700–900 Gy, suggesting that the grains screened-out by the rejection criteria may have the potential to cause palaeodose over-estimation, although this finding requires a more extensive investigation. Thermally transferred signals were found in the single K-feldspar grains post-IR IRSL protocol, and the proportion of thermally transferred signal to test-dose OSL signal (stimulation at 290 °C) from the natural dose was higher than from regenerative doses, and the proportion was grain- and dose-dependent. As such, TT-post-IR IRSL signals at 290 °C have the potential to cause dose underestimation, although this may be reduced by using larger test-dose irradiations. Our study demonstrates

  1. Systematic comparison of static and dynamic headspace sampling techniques for gas chromatography.

    Science.gov (United States)

    Kremser, Andreas; Jochmann, Maik A; Schmidt, Torsten C

    2016-09-01

    Six automated, headspace-based sample preparation techniques were used to extract volatile analytes from water with the goal of establishing a systematic comparison between commonly available instrumental alternatives. To that end, these six techniques were used in conjunction with the same gas chromatography instrument for analysis of a common set of volatile organic carbon (VOC) analytes. The methods were thereby divided into three classes: static sampling (by syringe or loop), static enrichment (SPME and PAL SPME Arrow), and dynamic enrichment (ITEX and trap sampling). For PAL SPME Arrow, different sorption phase materials were also included in the evaluation. To enable an effective comparison, method detection limits (MDLs), relative standard deviations (RSDs), and extraction yields were determined and are discussed for all techniques. While static sampling techniques exhibited sufficient extraction yields (approx. 10-20 %) to be reliably used down to approx. 100 ng L(-1), enrichment techniques displayed extraction yields of up to 80 %, resulting in MDLs down to the picogram per liter range. RSDs for all techniques were below 27 %. The choice on one of the different instrumental modes of operation (aforementioned classes) was thereby the most influential parameter in terms of extraction yields and MDLs. Individual methods inside each class showed smaller deviations, and the least influences were observed when evaluating different sorption phase materials for the individual enrichment techniques. The option of selecting specialized sorption phase materials may, however, be more important when analyzing analytes with different properties such as high polarity or the capability of specific molecular interactions. Graphical Abstract PAL SPME Arrow during the extraction of volatile analytes from the headspace of an aqueous sample.

  2. Multiple surveys employing a new sample-processing protocol reveal the genetic diversity of placozoans in Japan.

    Science.gov (United States)

    Miyazawa, Hideyuki; Nakano, Hiroaki

    2018-03-01

    Placozoans, flat free-living marine invertebrates, possess an extremely simple bauplan lacking neurons and muscle cells and represent one of the earliest-branching metazoan phyla. They are widely distributed from temperate to tropical oceans. Based on mitochondrial 16S rRNA sequences, 19 haplotypes forming seven distinct clades have been reported in placozoans to date. In Japan, placozoans have been found at nine locations, but 16S genotyping has been performed at only two of these locations. Here, we propose a new processing protocol, "ethanol-treated substrate sampling," for collecting placozoans from natural environments. We also report the collection of placozoans from three new locations, the islands of Shikine-jima, Chichi-jima, and Haha-jima, and we present the distribution of the 16S haplotypes of placozoans in Japan. Multiple surveys conducted at multiple locations yielded five haplotypes that were not reported previously, revealing high genetic diversity in Japan, especially at Shimoda and Shikine-jima Island. The observed geographic distribution patterns were different among haplotypes; some were widely distributed, while others were sampled only from a single location. However, samplings conducted on different dates at the same sites yielded different haplotypes, suggesting that placozoans of a given haplotype do not inhabit the same site constantly throughout the year. Continued sampling efforts conducted during all seasons at multiple locations worldwide and the development of molecular markers within the haplotypes are needed to reveal the geographic distribution pattern and dispersal history of placozoans in greater detail.

  3. Sampling phased array - a new technique for ultrasonic signal processing and imaging

    OpenAIRE

    Verkooijen, J.; Boulavinov, A.

    2008-01-01

    Over the past 10 years, the improvement in the field of microelectronics and computer engineering has led to significant advances in ultrasonic signal processing and image construction techniques that are currently being applied to non-destructive material evaluation. A new phased array technique, called 'Sampling Phased Array', has been developed in the Fraunhofer Institute for Non-Destructive Testing([1]). It realises a unique approach of measurement and processing of ultrasonic signals. Th...

  4. Sampling phased array, a new technique for ultrasonic signal processing and imaging now available to industry

    OpenAIRE

    Verkooijen, J.; Bulavinov, A.

    2008-01-01

    Over the past 10 years the improvement in the field of microelectronics and computer engineering has led to significant advances in ultrasonic signal processing and image construction techniques that are currently being applied to non-destructive material evaluation. A new phased array technique, called "Sampling Phased Array" has been developed in the Fraunhofer Institute for non-destructive testing [1]. It realizes a unique approach of measurement and processing of ultrasonic signals. The s...

  5. Chance constrained problems: penalty reformulation and performance of sample approximation technique

    Czech Academy of Sciences Publication Activity Database

    Branda, Martin

    2012-01-01

    Roč. 48, č. 1 (2012), s. 105-122 ISSN 0023-5954 R&D Projects: GA ČR(CZ) GBP402/12/G097 Institutional research plan: CEZ:AV0Z10750506 Keywords : chance constrained problems * penalty functions * asymptotic equivalence * sample approximation technique * investment problem Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.619, year: 2012 http://library.utia.cas.cz/separaty/2012/E/branda-chance constrained problems penalty reformulation and performance of sample approximation technique.pdf

  6. Human mixed lymphocyte cultures. Evaluation of microculture technique utilizing the multiple automated sample harvester (MASH)

    Science.gov (United States)

    Thurman, G. B.; Strong, D. M.; Ahmed, A.; Green, S. S.; Sell, K. W.; Hartzman, R. J.; Bach, F. H.

    1973-01-01

    Use of lymphocyte cultures for in vitro studies such as pretransplant histocompatibility testing has established the need for standardization of this technique. A microculture technique has been developed that has facilitated the culturing of lymphocytes and increased the quantity of cultures feasible, while lowering the variation between replicate samples. Cultures were prepared for determination of tritiated thymidine incorporation using a Multiple Automated Sample Harvester (MASH). Using this system, the parameters that influence the in vitro responsiveness of human lymphocytes to allogeneic lymphocytes have been investigated. PMID:4271568

  7. Experimental study of laser ablation as sample introduction technique for inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Van Winckel, S.

    2001-01-01

    The contribution consists of an abstract of a PhD thesis. In the PhD study, several complementary applications of laser-ablation were investigated in order to characterise experimentally laser ablation (LA) as a sample introduction technique for ICP-MS. Three applications of LA as a sample introduction technique are discussed: (1) the microchemical analysis of the patina of weathered marble; (2) the possibility to measure isotope ratios (in particular Pb isotope ratios in archaeological bronze artefacts); and (3) the determination of Si in Al as part of a dosimetric study of the BR2 reactor vessel

  8. Preparation of quality control samples for thyroid hormones T3 and T4 in radioimmunoassay techniques

    International Nuclear Information System (INIS)

    Ahmed, F.O.A.

    2006-03-01

    Today, the radioimmunoassay becomes one of the best techniques for quantitative analysis of very low concentration of different substances. RIA is being widely used in medical and research laboratories. To maintain high specificity and accuracy in RIA and other related techniques the quality controls must be introduced. In this dissertation quality control samples for thyroid hormones (Triiodothyronine T3 and Thyroxin T4), using RIA techniques. Ready made chinese T4, T3 RIA kits were used. IAEA statistical package were selected.(Author)

  9. Practical aspects of the resin bead technique for mass spectrometric sample loading

    International Nuclear Information System (INIS)

    Walker, R.L.; Pritchard, C.A.; Carter, J.A.; Smith, D.H.

    1976-07-01

    Using an anion resin bead as a loading vehicle for uranium and plutonium samples which are to be analyzed isotopically in a mass spectrometer has many advantages over conventional techniques. It is applicable to any laboratory routinely performing such analyses, but should be particularly relevant for Safeguards' purposes. Because the techniques required differ markedly from those of conventional methods, this report has been written to describe them in detail to enable those unfamiliar with the technique to master it with a minimum of trouble

  10. Recent advances in sample preparation techniques and methods of sulfonamides detection - A review.

    Science.gov (United States)

    Dmitrienko, Stanislava G; Kochuk, Elena V; Apyari, Vladimir V; Tolmacheva, Veronika V; Zolotov, Yury A

    2014-11-19

    Sulfonamides (SAs) have been the most widely used antimicrobial drugs for more than 70 years, and their residues in foodstuffs and environmental samples pose serious health hazards. For this reason, sensitive and specific methods for the quantification of these compounds in numerous matrices have been developed. This review intends to provide an updated overview of the recent trends over the past five years in sample preparation techniques and methods for detecting SAs. Examples of the sample preparation techniques, including liquid-liquid and solid-phase extraction, dispersive liquid-liquid microextraction and QuEChERS, are given. Different methods of detecting the SAs present in food and feed and in environmental, pharmaceutical and biological samples are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Analysis of pure and malachite green doped polysulfone sample using FT-IR technique

    Science.gov (United States)

    Nayak, Rashmi J.; Khare, P. K.; Nayak, J. G.

    2018-05-01

    The sample of pure and malachite green doped Polysulfone in the form of foil was prepared by isothermal immersion technique. For the preparation of pure sample 4 gm of Polysulfone was dissolved in 50 ml of Dimethyl farmamide (DMF) solvent, while for the preparation of doped sample 10 mg, 50 mg and 100 mg Malachite Green was mixed with 4 gm of Polysulfone respectively. For the study of structural characterization of these pure and doped sample, Fourier Transform Infra-Red Spectroscopy (FT-IR) technique was used. This study shows that the intensity of transmittance decreases as the ratio of doping increases in pure polysulfone. The reduction in intensity of transmittance is clearly apparent in the present case more over the bands were broader which indicates towards charge transfer interaction between the donar and acceptor molecule.

  12. A Survey of Congestion Control Techniques and Data Link Protocols in Satellite Networks

    OpenAIRE

    Fahmy, Sonia; Jain, Raj; Lu, Fang; Kalyanaraman, Shivkumar

    1998-01-01

    Satellite communication systems are the means of realizing a global broadband integrated services digital network. Due to the statistical nature of the integrated services traffic, the resulting rate fluctuations and burstiness render congestion control a complicated, yet indispensable function. The long propagation delay of the earth-satellite link further imposes severe demands and constraints on the congestion control schemes, as well as the media access control techniques and retransmissi...

  13. Ultrasound assisted extraction of food and natural products. Mechanisms, techniques, combinations, protocols and applications. A review.

    Science.gov (United States)

    Chemat, Farid; Rombaut, Natacha; Sicaire, Anne-Gaëlle; Meullemiestre, Alice; Fabiano-Tixier, Anne-Sylvie; Abert-Vian, Maryline

    2017-01-01

    This review presents a complete picture of current knowledge on ultrasound-assisted extraction (UAE) in food ingredients and products, nutraceutics, cosmetic, pharmaceutical and bioenergy applications. It provides the necessary theoretical background and some details about extraction by ultrasound, the techniques and their combinations, the mechanisms (fragmentation, erosion, capillarity, detexturation, and sonoporation), applications from laboratory to industry, security, and environmental impacts. In addition, the ultrasound extraction procedures and the important parameters influencing its performance are also included, together with the advantages and the drawbacks of each UAE techniques. Ultrasound-assisted extraction is a research topic, which affects several fields of modern plant-based chemistry. All the reported applications have shown that ultrasound-assisted extraction is a green and economically viable alternative to conventional techniques for food and natural products. The main benefits are decrease of extraction and processing time, the amount of energy and solvents used, unit operations, and CO 2 emissions. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Experimental Protocol to Determine the Chloride Threshold Value for Corrosion in Samples Taken from Reinforced Concrete Structures.

    Science.gov (United States)

    Angst, Ueli M; Boschmann, Carolina; Wagner, Matthias; Elsener, Bernhard

    2017-08-31

    The aging of reinforced concrete infrastructure in developed countries imposes an urgent need for methods to reliably assess the condition of these structures. Corrosion of the embedded reinforcing steel is the most frequent cause for degradation. While it is well known that the ability of a structure to withstand corrosion depends strongly on factors such as the materials used or the age, it is common practice to rely on threshold values stipulated in standards or textbooks. These threshold values for corrosion initiation (Ccrit) are independent of the actual properties of a certain structure, which clearly limits the accuracy of condition assessments and service life predictions. The practice of using tabulated values can be traced to the lack of reliable methods to determine Ccrit on-site and in the laboratory. Here, an experimental protocol to determine Ccrit for individual engineering structures or structural members is presented. A number of reinforced concrete samples are taken from structures and laboratory corrosion testing is performed. The main advantage of this method is that it ensures real conditions concerning parameters that are well known to greatly influence Ccrit, such as the steel-concrete interface, which cannot be representatively mimicked in laboratory-produced samples. At the same time, the accelerated corrosion test in the laboratory permits the reliable determination of Ccrit prior to corrosion initiation on the tested structure; this is a major advantage over all common condition assessment methods that only permit estimating the conditions for corrosion after initiation, i.e., when the structure is already damaged. The protocol yields the statistical distribution of Ccrit for the tested structure. This serves as a basis for probabilistic prediction models for the remaining time to corrosion, which is needed for maintenance planning. This method can potentially be used in material testing of civil infrastructures, similar to established

  15. Sampling methods and non-destructive examination techniques for large radioactive waste packages

    International Nuclear Information System (INIS)

    Green, T.H.; Smith, D.L.; Burgoyne, K.E.; Maxwell, D.J.; Norris, G.H.; Billington, D.M.; Pipe, R.G.; Smith, J.E.; Inman, C.M.

    1992-01-01

    Progress is reported on work undertaken to evaluate quality checking methods for radioactive wastes. A sampling rig was designed, fabricated and used to develop techniques for the destructive sampling of cemented simulant waste using remotely operated equipment. An engineered system for the containment of cooling water was designed and manufactured and successfully demonstrated with the drum and coring equipment mounted in both vertical and horizontal orientations. The preferred in-cell orientation was found to be with the drum and coring machinery mounted in a horizontal position. Small powdered samples can be taken from cemented homogeneous waste cores using a hollow drill/vacuum section technique with the preferred subsampling technique being to discard the outer 10 mm layer to obtain a representative sample of the cement core. Cement blends can be dissolved using fusion techniques and the resulting solutions are stable to gelling for periods in excess of one year. Although hydrochloric acid and nitric acid are promising solvents for dissolution of cement blends, the resultant solutions tend to form silicic acid gels. An estimate of the beta-emitter content of cemented waste packages can be obtained by a combination of non-destructive and destructive techniques. The errors will probably be in excess of +/-60 % at the 95 % confidence level. Real-time X-ray video-imaging techniques have been used to analyse drums of uncompressed, hand-compressed, in-drum compacted and high-force compacted (i.e. supercompacted) simulant waste. The results have confirmed the applicability of this technique for NDT of low-level waste. 8 refs., 12 figs., 3 tabs

  16. Comparison of Techniques for Sampling Adult Necrophilous Insects From Pig Carcasses.

    Science.gov (United States)

    Cruise, Angela; Hatano, Eduardo; Watson, David W; Schal, Coby

    2018-02-06

    Studies of the pre-colonization interval and mechanisms driving necrophilous insect ecological succession depend on effective sampling of adult insects and knowledge of their diel and successional activity patterns. The number of insects trapped, their diversity, and diel periodicity were compared with four sampling methods on neonate pigs. Sampling method, time of day and decomposition age of the pigs significantly affected the number of insects sampled from pigs. We also found significant interactions of sampling method and decomposition day, time of sampling and decomposition day. No single method was superior to the other methods during all three decomposition days. Sampling times after noon yielded the largest samples during the first 2 d of decomposition. On day 3 of decomposition however, all sampling times were equally effective. Therefore, to maximize insect collections from neonate pigs, the method used to sample must vary by decomposition day. The suction trap collected the most species-rich samples, but sticky trap samples were the most diverse, when both species richness and evenness were factored into a Shannon diversity index. Repeated sampling during the noon to 18:00 hours period was most effective to obtain the maximum diversity of trapped insects. The integration of multiple sampling techniques would most effectively sample the necrophilous insect community. However, because all four tested methods were deficient at sampling beetle species, future work should focus on optimizing the most promising methods, alone or in combinations, and incorporate hand-collections of beetles. © The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Experimental technique to measure thoron generation rate of building material samples using RAD7 detector

    International Nuclear Information System (INIS)

    Csige, I.; Szabó, Zs.; Szabó, Cs.

    2013-01-01

    Thoron ( 220 Rn) is the second most abundant radon isotope in our living environment. In some dwellings it is present in significant amount which calls for its identification and remediation. Indoor thoron originates mainly from building materials. In this work we have developed and tested an experimental technique to measure thoron generation rate in building material samples using RAD7 radon-thoron detector. The mathematical model of the measurement technique provides the thoron concentration response of RAD7 as a function of the sample thickness. For experimental validation of the technique an adobe building material sample was selected for measuring the thoron concentration at nineteen different sample thicknesses. Fitting the parameters of the model to the measurement results, both the generation rate and the diffusion length of thoron was estimated. We have also determined the optimal sample thickness for estimating the thoron generation rate from a single measurement. -- Highlights: • RAD7 is used for the determination of thoron generation rate (emanation). • The described model takes into account the thoron decay and attenuation. • The model describes well the experimental results. • A single point measurement method is offered at a determined sample thickness

  18. Sentinel Lymph Node Biopsy (SLNB) for Breast Cancer (BC) - Validation Protocol of the Technique

    International Nuclear Information System (INIS)

    Blidaru, A.; Bordea, C.I.; Condrea, Ileana; Albert, Paul

    2006-01-01

    Full text: The sentinel ganglion concept originates in the assumption according to which the primary tumor drains into a specific ganglionar area and then runs through the lymphatic nodes in an orderly, sequential mode. When neoplastic dissemination along the lymphatic pathway occurs, there is an initial invasion of a specific lymph node (rarely more than one) located on the drainage route. That firstly lymph node has been identified as the sentinel node, which mirrors the regional ganglionar status. In order to establish the indication for lymphadenectomy and avoid the situations in which such a surgical procedure would be of no use (N-), the only correct method consists in the identification and biopsy of the sentinel node. Radioactive tracing and/or use of vital staining enable the identification of the regional ganglionar group towards which the primary lesion is draining. The technique of sentinel lymph node identification and biopsy by means of radioactive tracing includes: - pre-surgical lymphoscintigraphy, - identification of the sentinel lymph node and its excisional biopsy, - intra-operative histopathological examination and immunohistochemical stains of the sentinel lymph node. Regional lymphadenectomy serves two major purposes: - diagnosis (axillary lymph node invasion represents an important prognostic factor) and therapeutic (to ensure local control of the disease). Regional lymph node invasion in breast cancer is directly related to the primary tumour size. In the less advanced stages (T1), as there is rarely invasion of the axillary lymph nodes, lymphadenectomy can be avoided in most cases. The paper presents the refinement of the technique, the validation of the method for the identification and biopsy of the sentinel lymph node in breast cancer using Tc99 and the intra-operative use of NEOPROBE 2000 gamma camera at the 'Prof. Dr. Alexandru Trestioreanu' Oncological Institute in Bucharest. 93 patients with primary breast cancer (T1, T2, N0

  19. Determination of metals in air samples using X-Ray fluorescence associated the APDC preconcentration technique

    Energy Technology Data Exchange (ETDEWEB)

    Nardes, Raysa C.; Santos, Ramon S.; Sanches, Francis A.C.R.A.; Gama Filho, Hamilton S.; Oliveira, Davi F.; Anjos, Marcelino J., E-mail: rc.nardes@gmail.com, E-mail: ramonziosp@yahoo.com.br, E-mail: francissanches@gmail.com, E-mail: hamiltongamafilho@hotmail.com, E-mail: davi.oliveira@uerj.br, E-mail: marcelin@uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Instituto de Fisica. Departamento de Fisica Aplicada e Termodinamica

    2015-07-01

    Air pollution has become one of the leading quality degradation factors of life for people in large urban centers. Studies indicate that the suspended particulate matter in the atmosphere is directly associated with risks to public health, in addition, it can cause damage to fauna, flora and public / cultural patrimonies. The inhalable particulate materials can cause the emergence and / or worsening of chronic diseases related to respiratory system and other diseases, such as reduced physical strength. In this study, we propose a new method to measure the concentration of total suspended particulate matter (TSP) in the air using an impinger as an air cleaning apparatus, preconcentration with APDC and Total Reflection X-ray Fluorescence technique (TXRF) to analyze the heavy metals present in the air. The samples were collected from five random points in the city of Rio de Janeiro/Brazil. Analyses of TXRF were performed at the Brazilian Synchrotron Light Laboratory (LNLS). The technique proved viable because it was able to detect five important metallic elements to environmental studies: Cr, Fe, Ni, Cu and Zn. This technique presented substantial efficiency in determining the elementary concentration of air pollutants, in addition to low cost. It can be concluded that the metals analysis technique in air samples using an impinger as sample collection instrument associated with a complexing agent (APDC) was viable because it is a low-cost technique, moreover, it was possible the detection of five important metal elements in environmental studies associated with industrial emissions and urban traffic. (author)

  20. Determination of metals in air samples using X-Ray fluorescence associated the APDC preconcentration technique

    International Nuclear Information System (INIS)

    Nardes, Raysa C.; Santos, Ramon S.; Sanches, Francis A.C.R.A.; Gama Filho, Hamilton S.; Oliveira, Davi F.; Anjos, Marcelino J.

    2015-01-01

    Air pollution has become one of the leading quality degradation factors of life for people in large urban centers. Studies indicate that the suspended particulate matter in the atmosphere is directly associated with risks to public health, in addition, it can cause damage to fauna, flora and public / cultural patrimonies. The inhalable particulate materials can cause the emergence and / or worsening of chronic diseases related to respiratory system and other diseases, such as reduced physical strength. In this study, we propose a new method to measure the concentration of total suspended particulate matter (TSP) in the air using an impinger as an air cleaning apparatus, preconcentration with APDC and Total Reflection X-ray Fluorescence technique (TXRF) to analyze the heavy metals present in the air. The samples were collected from five random points in the city of Rio de Janeiro/Brazil. Analyses of TXRF were performed at the Brazilian Synchrotron Light Laboratory (LNLS). The technique proved viable because it was able to detect five important metallic elements to environmental studies: Cr, Fe, Ni, Cu and Zn. This technique presented substantial efficiency in determining the elementary concentration of air pollutants, in addition to low cost. It can be concluded that the metals analysis technique in air samples using an impinger as sample collection instrument associated with a complexing agent (APDC) was viable because it is a low-cost technique, moreover, it was possible the detection of five important metal elements in environmental studies associated with industrial emissions and urban traffic. (author)

  1. 3D-Laser-Scanning Technique Applied to Bulk Density Measurements of Apollo Lunar Samples

    Science.gov (United States)

    Macke, R. J.; Kent, J. J.; Kiefer, W. S.; Britt, D. T.

    2015-01-01

    In order to better interpret gravimetric data from orbiters such as GRAIL and LRO to understand the subsurface composition and structure of the lunar crust, it is import to have a reliable database of the density and porosity of lunar materials. To this end, we have been surveying these physical properties in both lunar meteorites and Apollo lunar samples. To measure porosity, both grain density and bulk density are required. For bulk density, our group has historically utilized sub-mm bead immersion techniques extensively, though several factors have made this technique problematic for our work with Apollo samples. Samples allocated for measurement are often smaller than optimal for the technique, leading to large error bars. Also, for some samples we were required to use pure alumina beads instead of our usual glass beads. The alumina beads were subject to undesirable static effects, producing unreliable results. Other investigators have tested the use of 3d laser scanners on meteorites for measuring bulk volumes. Early work, though promising, was plagued with difficulties including poor response on dark or reflective surfaces, difficulty reproducing sharp edges, and large processing time for producing shape models. Due to progress in technology, however, laser scanners have improved considerably in recent years. We tested this technique on 27 lunar samples in the Apollo collection using a scanner at NASA Johnson Space Center. We found it to be reliable and more precise than beads, with the added benefit that it involves no direct contact with the sample, enabling the study of particularly friable samples for which bead immersion is not possible

  2. Review of sample preparation techniques for the analysis of pesticide residues in soil.

    Science.gov (United States)

    Tadeo, José L; Pérez, Rosa Ana; Albero, Beatriz; García-Valcárcel, Ana I; Sánchez-Brunete, Consuelo

    2012-01-01

    This paper reviews the sample preparation techniques used for the analysis of pesticides in soil. The present status and recent advances made during the last 5 years in these methods are discussed. The analysis of pesticide residues in soil requires the extraction of analytes from this matrix, followed by a cleanup procedure, when necessary, prior to their instrumental determination. The optimization of sample preparation is a very important part of the method development that can reduce the analysis time, the amount of solvent, and the size of samples. This review considers all aspects of sample preparation, including extraction and cleanup. Classical extraction techniques, such as shaking, Soxhlet, and ultrasonic-assisted extraction, and modern techniques like pressurized liquid extraction, microwave-assisted extraction, solid-phase microextraction and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) are reviewed. The different cleanup strategies applied for the purification of soil extracts are also discussed. In addition, the application of these techniques to environmental studies is considered.

  3. A review of analytical techniques for the determination of carbon-14 in environmental samples

    International Nuclear Information System (INIS)

    Milton, G.M.; Brown, R.M.

    1993-11-01

    This report contains a brief summary of analytical techniques commonly used for the determination of radiocarbon in a variety of environmental samples. Details of the applicable procedures developed and tested in the Environmental Research Branch at Chalk River Laboratories are appended

  4. Attempts to develop a new nuclear measurement technique of β-glucuronidase levels in biological samples

    International Nuclear Information System (INIS)

    Unak, T.; Avcibasi, U.; Yildirim, Y.; Cetinkaya, B.

    2003-01-01

    β-Glucuronidase is one of the most important hydrolytic enzymes in living systems and plays an essential role in the detoxification pathway of toxic materials incorporated into the metabolism. Some organs, especially liver and some tumour tissues, have high level of β-glucuronidase activity. As a result the enzymatic activity of some kind of tumour cells, the radiolabelled glucuronide conjugates of cytotoxic, as well as radiotoxic compounds have potentially very valuable diagnostic and therapeutic applications in cancer research. For this reason, a sensitive measurement of β-glucuronidase levels in normal and tumour tissues is a very important step for these kinds of applications. According to the classical measurement method of β-glucuronidase activity, in general, the quantity of phenolphthalein liberated from its glucuronide conjugate, i.e. phenolphthalein-glucuronide, by β-glucuronidase has been measured by use of the spectrophotometric technique. The lower detection limit of phenolphthalein by the spectrophotometric technique is about 1-3 mg. This means that the β-glucuronidase levels could not be detected in biological samples having lower levels of β-glucuronidase activity and therefore the applications of the spectrophotometric technique in cancer research are very seriously limited. Starting from this consideration, we recently attempted to develop a new nuclear technique to measure much lower concentrations of β-glucuronidase in biological samples. To improve the detection limit, phenolphthalein-glucuronide and also phenyl-N-glucuronide were radioiodinated with 131 I and their radioactivity was measured by use of the counting technique. Therefore, the quantity of phenolphthalein or aniline radioiodinated with 131 I and liberated by the deglucuronidation reactivity of β-glucuronidase was used in an attempt to measure levels lower than the spectrophotometric measurement technique. The results obtained clearly verified that 0.01 pg level of

  5. Atmospheric pressure surface sampling/ionization techniques for direct coupling of planar separations with mass spectrometry.

    Science.gov (United States)

    Pasilis, Sofie P; Van Berkel, Gary J

    2010-06-18

    Planar separations, which include thin layer chromatography and gel electrophoresis, are in widespread use as important and powerful tools for conducting separations of complex mixtures. To increase the utility of planar separations, new methods are needed that allow in situ characterization of the individual components of the separated mixtures. A large number of atmospheric pressure surface sampling and ionization techniques for use with mass spectrometry have emerged in the past several years, and several have been investigated as a means for mass spectrometric read-out of planar separations. In this article, we review the atmospheric pressure surface sampling and ionization techniques that have been used for the read-out of planar separation media. For each technique, we briefly explain the operational basics and discuss the analyte type for which it is appropriate and some specific applications from the literature. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  6. Staged protocol for the treatment of chronic femoral shaft osteomyelitis with Ilizarov's technique followed by the use of intramedullary locked nail

    Directory of Open Access Journals (Sweden)

    Po-Hsin Chou

    2017-06-01

    Conclusion: In the treatment of chronic femur osteomyelitis, the staged protocol of Ilizarov distraction osteogenesis followed by intramedullary nailing was safe and successful, and allowed for union, realignment, reorientation, and leg-length restoration. With regard to the soft tissue, this technique provides a unique type of reconstructive closure for infected wounds. It is suggested that the staged protocol is reliable in providing successful simultaneous reconstruction for bone and soft tissue defects without flap coverage.

  7. Heating and thermal control of brazing technique to break contamination path for potential Mars sample return

    Science.gov (United States)

    Bao, Xiaoqi; Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Campos, Sergio

    2017-04-01

    The potential return of Mars sample material is of great interest to the planetary science community, as it would enable extensive analysis of samples with highly sensitive laboratory instruments. It is important to make sure such a mission concept would not bring any living microbes, which may possibly exist on Mars, back to Earth's environment. In order to ensure the isolation of Mars microbes from Earth's Atmosphere, a brazing sealing and sterilizing technique was proposed to break the Mars-to-Earth contamination path. Effectively, heating the brazing zone in high vacuum space and controlling the sample temperature for integrity are key challenges to the implementation of this technique. The break-thechain procedures for container configurations, which are being considered, were simulated by multi-physics finite element models. Different heating methods including induction and resistive/radiation were evaluated. The temperature profiles of Martian samples in a proposed container structure were predicted. The results show that the sealing and sterilizing process can be controlled such that the samples temperature is maintained below the level that may cause damage, and that the brazing technique is a feasible approach to breaking the contamination path.

  8. Random sampling technique for ultra-fast computations of molecular opacities for exoplanet atmospheres

    Science.gov (United States)

    Min, M.

    2017-10-01

    Context. Opacities of molecules in exoplanet atmospheres rely on increasingly detailed line-lists for these molecules. The line lists available today contain for many species up to several billions of lines. Computation of the spectral line profile created by pressure and temperature broadening, the Voigt profile, of all of these lines is becoming a computational challenge. Aims: We aim to create a method to compute the Voigt profile in a way that automatically focusses the computation time into the strongest lines, while still maintaining the continuum contribution of the high number of weaker lines. Methods: Here, we outline a statistical line sampling technique that samples the Voigt profile quickly and with high accuracy. The number of samples is adjusted to the strength of the line and the local spectral line density. This automatically provides high accuracy line shapes for strong lines or lines that are spectrally isolated. The line sampling technique automatically preserves the integrated line opacity for all lines, thereby also providing the continuum opacity created by the large number of weak lines at very low computational cost. Results: The line sampling technique is tested for accuracy when computing line spectra and correlated-k tables. Extremely fast computations ( 3.5 × 105 lines per second per core on a standard current day desktop computer) with high accuracy (≤1% almost everywhere) are obtained. A detailed recipe on how to perform the computations is given.

  9. THE STUDY OF HEAVY METAL FROM ENVIRONMENTAL SAMPLES BY ATOMIC TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Ion V. POPESCU

    2011-05-01

    Full Text Available Using the Atomic Absorption Spectrometry (AAS and Energy Dispersive X-ray spectrometry (EDXRF techniques we analyzed the contents of heavy metals ( Cd, Cr, Ni, Pb, Ti, Sr, Co, Bi from eight wild mushrooms and soil substrate samples (48 samples of eight fungal species and 32 underlying soil samples, collected from ten forest sites of Dambovița County Romania. It was determined that the elements, especially heavy metals, in soil were characteristic of the acidic soils of the Romanian forest lands and are influenced by industrial pollution. Analytical possibilities of AAS and EDXRF analytical techniques have been compared and the heavy metal transfer from substrate to mushrooms has been studied. The coefficient of accumulation of essential and heavy metals has been calculated as well. Heavy metal contents of all analyzed mushrooms were generally higher than previously reported in literature.

  10. Toward greener analytical techniques for the absolute quantification of peptides in pharmaceutical and biological samples.

    Science.gov (United States)

    Van Eeckhaut, Ann; Mangelings, Debby

    2015-09-10

    Peptide-based biopharmaceuticals represent one of the fastest growing classes of new drug molecules. New reaction types included in the synthesis strategies to reduce the rapid metabolism of peptides, along with the availability of new formulation and delivery technologies, resulted in an increased marketing of peptide drug products. In this regard, the development of analytical methods for quantification of peptides in pharmaceutical and biological samples is of utmost importance. From the sample preparation step to their analysis by means of chromatographic or electrophoretic methods, many difficulties should be tackled to analyze them. Recent developments in analytical techniques emphasize more and more on the use of green analytical techniques. This review will discuss the progresses in and challenges observed during green analytical method development for the quantification of peptides in pharmaceutical and biological samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. [Influence of Natural Dissolved Organic Matter on the Passive Sampling Technique and its Application].

    Science.gov (United States)

    Yu, Shang-yun; Zhou, Yan-mei

    2015-08-01

    This paper studied the effects of different concentrations of natural dissolved organic matter (DOM) on the passive sampling technique. The results showed that the presence of DOM affected the organic pollutant adsorption ability of the membrane. For lgK(OW), 3-5, DOM had less impact on the adsorption of organic matter by the membrane; for lgK(OW), > 5.5, DOM significantly increased the adsorption capacity of the membrane. Meanwhile, LDPE passive sampling technique was applied to monitor PAHs and PAEs in pore water of three surface sediments in Taizi River. All of the target pollutants were detected in varying degrees at each sampling point. Finally, the quotient method was used to assess the ecological risks of PAHs and PAEs. The results showed that fluoranthene exceeded the reference value of the aquatic ecosystem, meaning there was a big ecological risk.

  12. Estimation of trace levels of plutonium in urine samples by fission track technique

    International Nuclear Information System (INIS)

    Sawant, P.D.; Prabhu, S.; Pendharkar, K.A.; Kalsi, P.C.

    2009-01-01

    Individual monitoring of radiation workers handling Pu in various nuclear installations requires the detection of trace levels of plutonium in bioassay samples. It is necessary to develop methods that can detect urinary excretion of Pu in fraction of mBq range. Therefore, a sensitive method such as fission track analysis has been developed for the measurement of trace levels of Pu in bioassay samples. In this technique, chemically separated plutonium from the sample and a Pu standard were electrodeposited on planchettes and covered with Lexan solid state nuclear track detector (SSNTD) and irradiated with thermal neutrons in APSARA reactor of Bhabha Atomic Research Centre, India. The fission track densities in the Lexan films of the sample and the standard were used to calculate the amount of Pu in the sample. The minimum amount of Pu that can be analyzed by this method using doubly distilled electronic grade (E. G.) reagents is about 12 μBq/L. (author)

  13. Imaging techniques and investigation protocols in pediatric emergency imaging; Aufnahmetechnik und Untersuchungsprotokolle beim paediatrischen Notfall

    Energy Technology Data Exchange (ETDEWEB)

    Scharitzer, M.; Hoermann, M.; Puig, S.; Prokop, M. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

    2002-03-01

    Paediatric emergencies demand a quick and efficient radiological investigation with special attention to specific adjustments related to patient age and radiation protection. Imaging modalities are improving rapidly and enable to diagnose childhood diseases and injuries more quickly, accurately and safely. This article provides an overview of imaging techniques adjusted to the age of the child and an overview of imaging strategies of common paediatric emergencies. Optimising the imaging parameters (digital radiography, different screen-film systems, exposure specifications) allows for substantial reduction of radiation dose. Spiral- and multislice-CT reduce scan time and enable a considerable reduction of radiation exposure if scanning parameters (pitch setting, tube current) are properly adjusted. MRI is still mainly used for neurological or spinal emergencies despite the advent of fast imaging sequences. The radiologist's task is to select an appropriate imaging strategy according to expected differential diagnosis and to adjust the imaging techniques to the individual patient. (orig.) [German] Das akut erkrankte Kind erfordert eine rasche radiologische Abklaerung mit besonderer Beruecksichtung der geaenderten Untersuchungsparameter bei gleichzeitig hohem Anspruch an den Strahlenschutz. Hochaufloesende Schallkoepfe, Multislice-CT und schnelle MR-Sequenzen erlauben eine bessere Anpassung der Untersuchungsmethoden an die Beduerfnisse in der Kinderradiologie. Ziel dieses Artikels ist eine Uebersicht ueber die verschiedenen radiologischen Untersuchungstechniken sowie deren Anpassung an kindliche Anforderungen und die Angabe von Untersuchungsalgorithmen der haeufigsten paediatrischen Notfaelle. In der Projektionsradiographie erlaubt die Optimierung der Aufnahmetechnik (digitale Radiographie, unterschiedliche Klassen von Film-Folien-Systemen, Belichtungsparameter) eine deutliche Reduktion der Strahlendosis bei diagnostisch ausreichender Qualitaet. Spiral- oder

  14. A radioanalytical technique using (n,2n) reaction for the elemental analysis of samples

    International Nuclear Information System (INIS)

    Labor, M.

    1985-11-01

    A technique to determine elemental composition of samples is reported. The principle of the technique employs the internal standard method and involves the resolution of complex annihilation spectra. The technique has been applied to the determination of the mass of nitrogen, msub(N), and that of potassium, msub(K), in known masses of potassium nitrate. The percentage difference between the calculated mass and actual masses in 2g and 3g of potassium nitrate is 1.0 and 0.7 respectively for potassium, and 1.0 for nitrogen. The use of more simultaneous equations than necessary in solving for msub(N) and msub(K) offers one of the advantages of the technique. (author)

  15. Accelerated Solvent Extraction: An Innovative Sample Extraction Technique for Natural Products

    International Nuclear Information System (INIS)

    Hazlina Ahmad Hassali; Azfar Hanif Abd Aziz; Rosniza Razali

    2015-01-01

    Accelerated solvent extraction (ASE) is one of the novel techniques that have been developed for the extraction of phytochemicals from plants in order to shorten the extraction time, decrease the solvent consumption, increase the extraction yield and enhance the quality of extracts. This technique combines elevated temperatures and pressure with liquid solvents. This paper gives a brief overview of accelerated solvent extraction technique for sample preparation and its application to the extraction of natural products. Through practical examples, the effects of operational parameters such as temperature, volume of solvent used, extraction time and extraction yields on the performance of ASE are discussed. It is demonstrated that ASE technique allows reduced solvent consumption and shorter extraction time, while the extraction yields are even higher than those obtained with conventional methods. (author)

  16. Lot quality assurance sampling techniques in health surveys in developing countries: advantages and current constraints.

    Science.gov (United States)

    Lanata, C F; Black, R E

    1991-01-01

    Traditional survey methods, which are generally costly and time-consuming, usually provide information at the regional or national level only. The utilization of lot quality assurance sampling (LQAS) methodology, developed in industry for quality control, makes it possible to use small sample sizes when conducting surveys in small geographical or population-based areas (lots). This article describes the practical use of LQAS for conducting health surveys to monitor health programmes in developing countries. Following a brief description of the method, the article explains how to build a sample frame and conduct the sampling to apply LQAS under field conditions. A detailed description of the procedure for selecting a sampling unit to monitor the health programme and a sample size is given. The sampling schemes utilizing LQAS applicable to health surveys, such as simple- and double-sampling schemes, are discussed. The interpretation of the survey results and the planning of subsequent rounds of LQAS surveys are also discussed. When describing the applicability of LQAS in health surveys in developing countries, the article considers current limitations for its use by health planners in charge of health programmes, and suggests ways to overcome these limitations through future research. It is hoped that with increasing attention being given to industrial sampling plans in general, and LQAS in particular, their utilization to monitor health programmes will provide health planners in developing countries with powerful techniques to help them achieve their health programme targets.

  17. Techniques of sample attack used in soil and mineral analysis. Phase I

    International Nuclear Information System (INIS)

    Chiu, N.W.; Dean, J.R.; Sill, C.W.

    1984-07-01

    Several techniques of sample attack for the determination of radioisotopes are reviewed. These techniques include: 1) digestion with nitric or hydrochloric acid in Parr digestion bomb, 2) digestion with a mixture of nitric and hydrochloric acids, 3) digestion with a mixture of hydrofluoric, nitric and perchloric acids, and 4) fusion with sodium carbonate, potassium fluoride or alkali pyrosulfates. The effectiveness of these techniques to decompose various soils and minerals containing radioisotopes such as lead-210 uranium, thorium and radium-226 are discussed. The combined procedure of potassium fluoride fusion followed by alkali pyrosulfate fusion is recommended for radium-226, uranium and thorium analysis. This technique guarantees the complete dissolution of samples containing refractory materials such as silica, silicates, carbides, oxides and sulfates. For the lead-210 analysis, the procedure of digestion with a mixture of hydrofluoric, nitric and perchloric acids followed by fusion with alkali pyrosulfate is recommended. These two procedures are detailed. Schemes for the sequential separation of the radioisotopes from a dissolved sample solution are outlined. Procedures for radiochemical analysis are suggested

  18. The role of graphene-based sorbents in modern sample preparation techniques.

    Science.gov (United States)

    de Toffoli, Ana Lúcia; Maciel, Edvaldo Vasconcelos Soares; Fumes, Bruno Henrique; Lanças, Fernando Mauro

    2018-01-01

    The application of graphene-based sorbents in sample preparation techniques has increased significantly since 2011. These materials have good physicochemical properties to be used as sorbent and have shown excellent results in different sample preparation techniques. Graphene and its precursor graphene oxide have been considered to be good candidates to improve the extraction and concentration of different classes of target compounds (e.g., parabens, polycyclic aromatic hydrocarbon, pyrethroids, triazines, and so on) present in complex matrices. Its applications have been employed during the analysis of different matrices (e.g., environmental, biological and food). In this review, we highlight the most important characteristics of graphene-based material, their properties, synthesis routes, and the most important applications in both off-line and on-line sample preparation techniques. The discussion of the off-line approaches includes methods derived from conventional solid-phase extraction focusing on the miniaturized magnetic and dispersive modes. The modes of microextraction techniques called stir bar sorptive extraction, solid phase microextraction, and microextraction by packed sorbent are discussed. The on-line approaches focus on the use of graphene-based material mainly in on-line solid phase extraction, its variation called in-tube solid-phase microextraction, and on-line microdialysis systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Study of an optimization protocol for radiographic techniques in computerized radiology

    International Nuclear Information System (INIS)

    Abrantes, Marcos Eugenio Silva

    2015-01-01

    This work is designed to produce information for the improvement of image quality to deployment in a radiology department based on previous reviews of the images by questionnaires of acceptance and quality e recognition of the parameters used in chest radiographic techniques. The data collected were divided by male, female, PA and LAT thickness, body mass index, biotypes, anthropomorphic parameters and body evaluation associated with constant voltage and the additional filtration. The results show the predominance of 35 and 40 constants with additional filtration from 0.5 to 1.5 mmAl, voltage in male: (PA and LAT) 86-92 kV and 96-112 kV, female: 85-98 kV and 96-112 kV. The charge applied to the tube for males: (PA and LAT) 5-10 mA.s and 5-16 mA.s, female: (PA and LAT) 6.3-8 mA.s and 9-14 mA.s. Absorbed doses for males: (PA and PF) 0.04-0.17 mGy and 0.03-0.19 mGy and from female (PA and PF) from 0.03-0.22 mGy and 0, 04-0.17 mGy. This procedure can be used in radiology department to implement and acceptance in the quality of images. (author)

  20. 238U And 232Th Concentration In Rock Samples using Alpha Autoradiography and Gamma Spectroscopy Techniques

    International Nuclear Information System (INIS)

    Hafez, A.F.; El-Farrash, A.H.; Yousef, H.A.

    2009-01-01

    The activity concentrations of uranium and thorium were measured for some rock samples selected from Dahab region in the south tip of Sinai. In order to detect any harmful radiation that would affect on the tourists and is becoming economic resource because Dahab have open fields of tourism in Egypt. The activity concentration of uranium and thorium in rocks samples was measured using two techniques. The first is .-autoradiography technique with LR-115 and CR-39 detectors and the second is gamma spectroscopic technique with NaI(Tl) detector. It was found that the average activity concentrations of uranium and thorium using .-autoradiography technique ranged from 6.41-49.31 Bqkg-1, 4.86- 40.87 Bqkg-1 respectively and by gamma detector are ranged from 6.70- 49.50 Bqkg-1, 4.47- 42.33 Bqkg-1 respectively. From the obtained data we can conclude that there is no radioactive healthy hazard for human and living beings in the area under investigation. It was found that there are no big differences between the calculated thorium to uranium ratios in both techniques

  1. Review of online coupling of sample preparation techniques with liquid chromatography.

    Science.gov (United States)

    Pan, Jialiang; Zhang, Chengjiang; Zhang, Zhuomin; Li, Gongke

    2014-03-07

    Sample preparation is still considered as the bottleneck of the whole analytical procedure, and efforts has been conducted towards the automation, improvement of sensitivity and accuracy, and low comsuption of organic solvents. Development of online sample preparation techniques (SP) coupled with liquid chromatography (LC) is a promising way to achieve these goals, which has attracted great attention. This article reviews the recent advances on the online SP-LC techniques. Various online SP techniques have been described and summarized, including solid-phase-based extraction, liquid-phase-based extraction assisted with membrane, microwave assisted extraction, ultrasonic assisted extraction, accelerated solvent extraction and supercritical fluids extraction. Specially, the coupling approaches of online SP-LC systems and the corresponding interfaces have been discussed and reviewed in detail, such as online injector, autosampler combined with transport unit, desorption chamber and column switching. Typical applications of the online SP-LC techniques have been summarized. Then the problems and expected trends in this field are attempted to be discussed and proposed in order to encourage the further development of online SP-LC techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Advances in modern sample preparation techniques using microwaves assisted chemistry for metal species determination (W1)

    International Nuclear Information System (INIS)

    Ponard, O.F.X.

    2002-01-01

    Full text: Sample preparation has long been the bottleneck of environmental analysis for both total and species specific analysis. Digestion, extraction and preparation of the analytes are relying on a series of chemical reactions. The introduction of microwave assisted sample preparation has first been viewed as a mean to accelerate the kinetics of digestion of the matrix for total elements and fast samples preparation procedures. However, the extensive development and success of microwave digestion procedures in total elemental analysis has now allowed to have a larger insight of the perspectives offered by this technique. Microwave technologies now offer to have a precise control of the temperature and indirectly control the reaction kinetics taking place during the sample preparation procedures. Microwave assisted chemistry permits to perform simultaneously the fundamental steps required for metal species extraction and derivatization. The number of sample preparation steps used for organotin or organomercury species have been reduced to one and the total time of sample preparation brought down for a few hours to some minutes. Further, the developments of GC/ICP/MS techniques allow to routinely use speciated isotopic dilution methods has internal probe of the chemical reactions. These new approaches allow us to use the addition of the labeled species for isotopic dilution as a mean to evaluate and follow the chemical processes taking place during the extraction procedure. These procedures will help us to understand and check for the stability of the analytes during the chemistry of the sample preparation procedure and bring some insights of the chemistry taking place during the extraction. Understanding the different mechanisms involved in the sample preparation steps will allow us in return to further improve all theses procedures and bring us to the horizon of 'on-line sample preparation and detection'. (author)

  3. Determination of some trace elements in biological samples using XRF and TXRF techniques

    International Nuclear Information System (INIS)

    Khuder, A.; Karjou, J.; Sawan, M. K.

    2006-07-01

    XRF and TXRF techniques were successfully used for the multi-element determination of trace elements in whole blood and human head hair samples. This was achieved by the direct analysis using XRF technique with different collimation units and by the optimized chemical procedures for TXRF analysis. Light element of S and P were preferably determined by XRF with primary x-ray excitation, while, elements of K, Ca, Fe, and Br were determined with a very good accuracy and precision using XRF with Cu- and Mo-secondary targets. The chemical procedure dependent on the preconcentration of trace elements by APDC was superiorly used for the determination of traces of Ni and Pb in the range of 1.0-1.7 μg/dl and 11-23 μg/dl, respectively, in whole blood samples by TXRF technique; determination of other elements as Cu and Zn was also achievable using this approach. Rb in whole blood samples was determined directly after the digestion of samples using PTFE-bomb for TXRF analysis. (author)

  4. Direct sampling technique of bees on Vriesea philippocoburgii (Bromeliaceae, Tillandsioideae flowers

    Directory of Open Access Journals (Sweden)

    Afonso Inácio Orth

    2004-11-01

    Full Text Available In our study on Vriesea philippocoburgii Wawra pollination, due to the small proportion of flowers in anthesis on a single day and the damage caused to inflorescences when netting directly on flowers, we used the direct sampling technique (DST of bees on flowers. This technique was applied to 40 flowering plants and resulted in the capture of 160 specimens, belonging to nine genera of Apoidea and separated into 19 morph species. As DST maintains the integrity of flowers for later Bees’ visits, it can enhance the survey’s performance, constituting an alternative methodology for the collection of bees visiting flowering plants.

  5. Determination of trace element contents in grass samples for cattle feeding using NAA techniques

    Energy Technology Data Exchange (ETDEWEB)

    Yusof, Alias Mohamad; Jagir Singh, Jasbir Kaur

    1987-09-01

    An investigation on trace elements contents in six types of grass samples used for cattle feeding have been carried out using NAA techniques. The grass samples, Mardi Digit, African Star, Signal, Guinea, Setaria and Setaria Splendida were found to contain at least 19 trace elements in varying concentrations. The results were compared to the figures obtained from available sources to ascertain the status as to whether the grass samples studied would satisfy the minimum requirements of trace elements present in grass for cattle feeding or otherwise. Preference made on the suitability of the grass samples for cattle feeding was based on the availability and abundance of the trace elements, taking into account factors such as the degree of toxicity, inadequate amounts and contamination due to the presence of other trace elements not essential for cattle feeding.

  6. Determination of trace element contents in grass samples for cattle feeding using NAA techniques

    International Nuclear Information System (INIS)

    Alias Mohamad Yusof; Jasbir Kaur Jagir Singh

    1987-01-01

    An investigation on trace elements contents in six types of grass samples used for cattle feeding have been carried out using NAA techniques. The grass samples, Mardi Digit, African Star, Signal, Guinea, Setaria and Setaria Splendida were found to contain at least 19 trace elements in varying concentrations. The results were compared to the figures obtained from available sources to ascertain the status as to whether the grass samples studied would satisfy the minimum requirements of trace elements present in grass for cattle feeding or otherwise. Preference made on the suitability of the grass samples for cattle feeding was based on the availability and abundance of the trace elements, taking into account factors such as the degree of toxicity, inadequate amounts and contamination due to the presence of other trace elements not essential for cattle feeding. (author)

  7. Sampling methods for rumen microbial counts by Real-Time PCR techniques

    Directory of Open Access Journals (Sweden)

    S. Puppo

    2010-02-01

    Full Text Available Fresh rumen samples were withdrawn from 4 cannulated buffalo females fed a fibrous diets in order to quantify bacteria concentration in the rumen by Real-Time PCR techniques. To obtain DNA of a good quality from whole rumen fluid, eight (M1-M8 different pre-filtration methods (cheese cloths, glass-fibre and nylon filter in combination with various centrifugation speeds (1000, 5000 and 14,000 rpm were tested. Genomic DNA extraction was performed either on fresh or frozen samples (-20°C. The quantitative bacteria analysis was realized according to Real-Time PCR procedure for Butyrivibrio fibrisolvens reported in literature. M5 resulted the best sampling procedure allowing to obtain a suitable genomic DNA. No differences were revealed between fresh and frozen samples.

  8. Application of digital sampling techniques to particle identification in scintillation detectors

    International Nuclear Information System (INIS)

    Bardelli, L.; Bini, M.; Poggi, G.; Taccetti, N.

    2002-01-01

    In this paper, the use of a fast digitizing system for identification of fast charged particles with scintillation detectors is discussed. The three-layer phoswich detectors developed in the framework of the FIASCO experiment for the detection of light charged particles (LCP) and intermediate mass fragments (IMF) emitted in heavy-ion collisions at Fermi energies are briefly discussed. The standard analog electronics treatment of the signals for particle identification is illustrated. After a description of the digitizer designed to perform a fast digital sampling of the phoswich signals, the feasibility of particle identification on the sampled data is demonstrated. The results obtained with two different pulse shape discrimination analyses based on the digitally sampled data are compared with the standard analog signal treatment. The obtained results suggest, for the present application, the replacement of the analog methods with the digital sampling technique

  9. Uranium content measurement in drinking water samples using track etch technique

    International Nuclear Information System (INIS)

    Kumar, Mukesh; Kumar, Ajay; Singh, Surinder; Mahajan, R.K.; Walia, T.P.S.

    2003-01-01

    The concentration of uranium has been assessed in drinking water samples collected from different locations in Bathinda district, Punjab, India. The water samples are taken from hand pumps and tube wells. Uranium is determined using fission track technique. Uranium concentration in the water samples varies from 1.65±0.06 to 74.98±0.38 μg/l. These values are compared with safe limit values recommended for drinking water. Most of the water samples are found to have uranium concentration above the safe limit. Analysis of some heavy metals (Zn, Cd, Pb and Cu) in water is also done in order to see if some correlation exists between the concentration of uranium and these heavy metals. A weak positive correlation has been observed between the concentration of uranium and heavy metals of Pb, Cd and Cu

  10. Recent Trends in Microextraction Techniques Employed in Analytical and Bioanalytical Sample Preparation

    Directory of Open Access Journals (Sweden)

    Abuzar Kabir

    2017-12-01

    Full Text Available Sample preparation has been recognized as a major step in the chemical analysis workflow. As such, substantial efforts have been made in recent years to simplify the overall sample preparation process. Major focusses of these efforts have included miniaturization of the extraction device; minimizing/eliminating toxic and hazardous organic solvent consumption; eliminating sample pre-treatment and post-treatment steps; reducing the sample volume requirement; reducing extraction equilibrium time, maximizing extraction efficiency etc. All these improved attributes are congruent with the Green Analytical Chemistry (GAC principles. Classical sample preparation techniques such as solid phase extraction (SPE and liquid-liquid extraction (LLE are being rapidly replaced with emerging miniaturized and environmentally friendly techniques such as Solid Phase Micro Extraction (SPME, Stir bar Sorptive Extraction (SBSE, Micro Extraction by Packed Sorbent (MEPS, Fabric Phase Sorptive Extraction (FPSE, and Dispersive Liquid-Liquid Micro Extraction (DLLME. In addition to the development of many new generic extraction sorbents in recent years, a large number of molecularly imprinted polymers (MIPs created using different template molecules have also enriched the large cache of microextraction sorbents. Application of nanoparticles as high-performance extraction sorbents has undoubtedly elevated the extraction efficiency and method sensitivity of modern chromatographic analyses to a new level. Combining magnetic nanoparticles with many microextraction sorbents has opened up new possibilities to extract target analytes from sample matrices containing high volumes of matrix interferents. The aim of the current review is to critically audit the progress of microextraction techniques in recent years, which has indisputably transformed the analytical chemistry practices, from biological and therapeutic drug monitoring to the environmental field; from foods to phyto

  11. Development of Large Sample Neutron Activation Technique for New Applications in Thailand

    International Nuclear Information System (INIS)

    Laoharojanaphand, S.; Tippayakul, C.; Wonglee, S.; Channuie, J.

    2018-01-01

    The development of the Large Sample Neutron Activation Analysis (LSNAA) in Thailand is presented in this paper. The technique had been firstly developed with rice sample as the test subject. The Thai Research Reactor-1/Modification 1 (TRR-1/M1) was used as the neutron source. The first step was to select and characterize an appropriate irradiation facility for the research. An out-core irradiation facility (A4 position) was first attempted. The results performed with the A4 facility were then used as guides for the subsequent experiments with the thermal column facility. The characterization of the thermal column was performed with Cu-wire to determine spatial distribution without and with rice sample. The flux depression without rice sample was observed to be less than 30% while the flux depression with rice sample increased to within 60%. The flux monitors internal to the rice sample were used to determine average flux over the rice sample. The gamma selfshielding effect during gamma measurement was corrected using the Monte Carlo simulation. The ratio between the efficiencies of the volume source and the point source for each energy point was calculated by the MCNPX code. The research team adopted the k0-NAA methodology to calculate the element concentration in the research. The k0-NAA program which developed by IAEA was set up to simulate the conditions of the irradiation and measurement facilities used in this research. The element concentrations in the bulk rice sample were then calculated taking into account the flux depression and gamma efficiency corrections. At the moment, the results still show large discrepancies with the reference values. However, more research on the validation will be performed to identify sources of errors. Moreover, this LS-NAA technique was introduced for the activation analysis of the IAEA archaeological mock-up. The results are provided in this report. (author)

  12. Characterization of Some Iraqi Archaeological Samples Using IBA, Analytical X-ray and Other Complementary Techniques

    International Nuclear Information System (INIS)

    Al-Sarraj, Ziyad Shihab; Damboos, Hassan I; Roumie, Mohamad

    2012-01-01

    The present work aimed at investigating the compositions and microstructures of some archaeological samples which dated back to various periods of the ancient Iraqi civilizations using PIXE, XRF, XRD, and SEM techniques. The models selected for the study (ceramics, glaze, etc.) were diverse in size and nature, therefore a limited number of samples were then butted from them by a small diamond wheel. Conventional powder metallurgy method was then used to prepare the samples. Dried samples were then coated with a thin layer of carbon, and analyzed using the ion beam accelerator of the LAEC. Three other groups of samples were also prepared for the purpose of analysis by X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscope (SEM). Analysis results of the chemical composition showed good agreement between the various techniques as well as for phases, while the fine structure analysis obtained by optical and scanning microscopy exhibited features of a structure where it got an intensified densification in the final stage of sintering and accompanied by quasi-homogeneous distribution of the closed pores. This will lead to the conclusion that the temperature used for sintering by ancient Iraqi was sufficient and it may fall in the range between 950-1200°C, also the mixes and the forming methods used by them, were both suitable to obtain good sintered bodies with even distribution of pores. A ring-shaped trace noticed in SEM micrographs need more work and study to explain what it is?

  13. Determination of elements in industrial waste sample and TENORM using XRF Technique in Nuclear Malaysia

    International Nuclear Information System (INIS)

    Paulus, W.; Sarimah Mahat; Meor Yusoff Meor Sulaiman

    2011-01-01

    Industrial waste such as aluminium dross and TENORM waste, oil sludge has been used as sample in this research. Determination of main elements by using X-Ray Fluorescence (XRF) in Material Technology Group, Malaysian Nuclear Agency. Results shows that main elements in these samples, aluminium and silicon, respectively. Thereby, this research shows that XRF can be considered as one of the techniques that can be used in waste characterization and furthermore, it can help researchers and engineer in the research related to waste treatment especially radioactive waste. (author)

  14. Application of nuclear and allied techniques for the characterisation of forensic samples

    International Nuclear Information System (INIS)

    Sudersanan, M.; Kayasth, S.R.; Pant, D.R.; Chattopadhyay, N.; Bhattacharyya, C.N.

    2002-01-01

    Full text: Forensic science deals with the application of various techniques for physics, chemistry and biology for crime investigation. The legal implication of such analysis put considerable restriction on the choice of analytical techniques. Moreover, the unknown nature of the materials, the limited availability of samples and the large number of elements to be analysed put considerable strain on the analytical chemist on the selection of the appropriate technique. The availability of nuclear techniques has considerably enhanced the scope of forensic analysis. This paper deals with the recent results on the use of nuclear and allied analytical techniques for forensic applications. One of the important types of samples of forensic importance pertain to the identification of gunshot residues. The use of nuclear techniques has considerably simplified the interpretation of results through the use of appropriate elements like Ba, Cu, Sb, Zn, As and Sn etc. The combination of non-nuclear techniques for elements like Pb and Ni which are not easily amenable to be analysed by NAA and the use of appropriate separation procedure has led to the use of this method as a valid and versatile analytical procedure. In view of the presence of a large amounts of extraneous materials like cloth, body tissues etc in these samples and the limited availability of materials, the procedures for sample collection, dissolution and analysis have been standardized. Analysis of unknown materials like powders, metallic pieces etc. for the possible presence of nuclear materials or as materials in illicit trafficking is becoming important in recent years. The use of multi-technique approach is important in this case. Use of non-destructive techniques like XRF and radioactive counting enables the preliminary identification of materials and for the detection of radioactivity. Subsequent analysis by NAA or other appropriate analytical methods allows the characterization of the materials. Such

  15. Coacervative extraction as a green technique for sample preparation for the analysis of organic compounds.

    Science.gov (United States)

    Melnyk, A; Wolska, L; Namieśnik, J

    2014-04-25

    One of the present trends in analytical chemistry is miniaturization, which is one of the methods of green analytical chemistry application. A particular emphasis is placed on the elimination of the use of large amounts of organic solvents which are toxic and harmful to the environment, maintaining high efficiency of the extraction process, high recovery values and low values of quantification (LOQ) and detection (LOD) limits. These requirements are fulfilled by coacervative extraction (CAE) technique. In this review, theoretical aspects of the coacervation process are presented along with environmental and bioanalytical applications of this technique, its advantages, limitations and competitiveness with other techniques. Due to its simplicity and rapidity, CAE is an excellent alternative for currently practiced procedures of sample preparation for the analysis of organic compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Nuclear techniques for trace element analysis. PIXE and its applications to biomedical samples

    International Nuclear Information System (INIS)

    Cata-Danil, I.; Moro, R.; Gialanella, G.

    1996-01-01

    Problems in understanding the role of trace elements in the functioning of life processes are discussed. A brief review of the state of the PIXE technique is given. Principles and recent advances in beam systems, instrumentation and sample handling are covered. A rather comprehensive list of references regarding varies methodological aspects and biomedical applications is given. Some applications are discussed. In particular, preliminary results of an investigation regarding pediatric obesity are presented. (author) 5 tabs., 21 refs

  17. A simple technique for measuring the superconducting critical temperature of small (>= 10 μg) samples

    International Nuclear Information System (INIS)

    Pereira, R.F.R.; Meyer, E.; Silveira, M.F. da.

    1983-01-01

    A simple technique for measuring the superconducting critical temperature of small (>=10μg) samples is described. The apparatus is built in the form of a probe, which can be introduced directly into a liquid He storage dewar and permits the determination of the critical temperature, with an imprecision of +- 0.05 K above 4.2 K, in about 10 minutes. (Author) [pt

  18. Multi-element analysis of lubricant oil by WDXRF technique using thin-film sample preparation

    International Nuclear Information System (INIS)

    Scapin, M. A.; Salvador, V. L. R.; Lopes, C. D.; Sato, I. M.

    2006-01-01

    The quantitative analysis of the chemical elements in matrices like oils or gels represents a challenge for the analytical chemists. The classics methods or instrumental techniques such as atomic absorption spectrometry (AAS) and plasma optical emission spectrometry (ICP-OES) need chemical treatments, mainly sample dissolution and degradation processes. X-ray fluorescence technique allows a direct and multi-element analysis without previous sample treatments. In this work, a sensible method for the determination of elements Mg, Al, Si, P, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Mo, Ag, Sn, Ba and Pb in lubricating oil is presented. The x-ray fluorescence (WDXRF) technique using linear regression method and thin film sample preparation was used. The validation of the methodology (repeatability and accuracy) was obtained by the analysis of the standard reference materials SRM Alpha AESAR lot 703527D, applying the Chauvenet, Cochrane, ANOVA and Z-score statistical tests. The method presents a relative standard deviation lower than 10% for all the elements, except for Pb determination (RSD Pb 15%). The Z-score values for all the elements were in the range -2 < Z < 2, indicating a very good accuracy.(Full text)

  19. Detection of equine herpesvirus in horses with idiopathic keratoconjunctivitis and comparison of three sampling techniques.

    Science.gov (United States)

    Hollingsworth, Steven R; Pusterla, Nicola; Kass, Philip H; Good, Kathryn L; Brault, Stephanie A; Maggs, David J

    2015-09-01

    To determine the role of equine herpesvirus (EHV) in idiopathic keratoconjunctivitis in horses and to determine whether sample collection method affects detection of EHV DNA by quantitative polymerase chain reaction (qPCR). Twelve horses with idiopathic keratoconjunctivitis and six horses without signs of ophthalmic disease. Conjunctival swabs, corneal scrapings, and conjunctival biopsies were collected from 18 horses: 12 clinical cases with idiopathic keratoconjunctivitis and six euthanized controls. In horses with both eyes involved, the samples were taken from the eye judged to be more severely affected. Samples were tested with qPCR for EHV-1, EHV-2, EHV-4, and EHV-5 DNA. Quantity of EHV DNA and viral replicative activity were compared between the two populations and among the different sampling techniques; relative sensitivities of the sampling techniques were determined. Prevalence of EHV DNA as assessed by qPCR did not differ significantly between control horses and those with idiopathic keratoconjunctivitis. Sampling by conjunctival swab was more likely to yield viral DNA as assessed by qPCR than was conjunctival biopsy. EHV-1 and EHV-4 DNA were not detected in either normal or IKC-affected horses; EHV-2 DNA was detected in two of 12 affected horses but not in normal horses. EHV-5 DNA was commonly found in ophthalmically normal horses and horses with idiopathic keratoconjunctivitis. Because EHV-5 DNA was commonly found in control horses and in horses with idiopathic keratoconjunctivitis, qPCR was not useful for the etiological diagnosis of equine keratoconjunctivitis. Conjunctival swabs were significantly better at obtaining viral DNA samples than conjunctival biopsy in horses in which EHV-5 DNA was found. © 2015 American College of Veterinary Ophthalmologists.

  20. Improvement in quality of life and sexual functioning in a comorbid sample after the unified protocol transdiagnostic group treatment.

    Science.gov (United States)

    de Ornelas Maia, Ana Claudia Corrêa; Sanford, Jenny; Boettcher, Hannah; Nardi, Antonio E; Barlow, David

    2017-10-01

    Patients with multiple mental disorders often experience sexual dysfunction and reduced quality of life. The unified protocol (UP) is a transdiagnostic treatment for emotional disorders that has the potential to improve quality of life and sexual functioning via improved emotion management. The present study evaluates changes in quality of life and sexual functioning in a highly comorbid sample treated with the UP in a group format. Forty-eight patients were randomly assigned to either a UP active-treatment group or a medication-only control group. Treatment was delivered in 14 sessions over the course of 4 months. Symptoms of anxiety and depression were assessed using the Beck Anxiety Inventory and Beck Depression Inventory. Sexual functioning was assessed by the Arizona Sexual Experience Scale (ASEX), and quality of life was assessed by the World Health Organization Quality of Life-BREF scale (WHOQOL-BREF). Quality of life, anxiety and depression all significantly improved among participants treated with the UP. Some improvement in sexual functioning was also noted. The results support the efficacy of the UP in improving quality of life and sexual functioning in comorbid patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Testing the efficiency of rover science protocols for robotic sample selection: A GeoHeuristic Operational Strategies Test

    Science.gov (United States)

    Yingst, R. A.; Bartley, J. K.; Chidsey, T. C.; Cohen, B. A.; Gilleaudeau, G. J.; Hynek, B. M.; Kah, L. C.; Minitti, M. E.; Williams, R. M. E.; Black, S.; Gemperline, J.; Schaufler, R.; Thomas, R. J.

    2018-05-01

    The GHOST field tests are designed to isolate and test science-driven rover operations protocols, to determine best practices. During a recent field test at a potential Mars 2020 landing site analog, we tested two Mars Science Laboratory data-acquisition and decision-making methods to assess resulting science return and sample quality: a linear method, where sites of interest are studied in the order encountered, and a "walkabout-first" method, where sites of interest are examined remotely before down-selecting to a subset of sites that are interrogated with more resource-intensive instruments. The walkabout method cost less time and fewer resources, while increasing confidence in interpretations. Contextual data critical to evaluating site geology was acquired earlier than for the linear method, and given a higher priority, which resulted in development of more mature hypotheses earlier in the analysis process. Combined, this saved time and energy in the collection of data with more limited spatial coverage. Based on these results, we suggest that the walkabout method be used where doing so would provide early context and time for the science team to develop hypotheses-critical tests; and that in gathering context, coverage may be more important than higher resolution.

  2. Multiple sensitive estimation and optimal sample size allocation in the item sum technique.

    Science.gov (United States)

    Perri, Pier Francesco; Rueda García, María Del Mar; Cobo Rodríguez, Beatriz

    2018-01-01

    For surveys of sensitive issues in life sciences, statistical procedures can be used to reduce nonresponse and social desirability response bias. Both of these phenomena provoke nonsampling errors that are difficult to deal with and can seriously flaw the validity of the analyses. The item sum technique (IST) is a very recent indirect questioning method derived from the item count technique that seeks to procure more reliable responses on quantitative items than direct questioning while preserving respondents' anonymity. This article addresses two important questions concerning the IST: (i) its implementation when two or more sensitive variables are investigated and efficient estimates of their unknown population means are required; (ii) the determination of the optimal sample size to achieve minimum variance estimates. These aspects are of great relevance for survey practitioners engaged in sensitive research and, to the best of our knowledge, were not studied so far. In this article, theoretical results for multiple estimation and optimal allocation are obtained under a generic sampling design and then particularized to simple random sampling and stratified sampling designs. Theoretical considerations are integrated with a number of simulation studies based on data from two real surveys and conducted to ascertain the efficiency gain derived from optimal allocation in different situations. One of the surveys concerns cannabis consumption among university students. Our findings highlight some methodological advances that can be obtained in life sciences IST surveys when optimal allocation is achieved. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Evaluation of primary immunization coverage of infants under universal immunization programme in an urban area of Bangalore city using cluster sampling and lot quality assurance sampling techniques

    Directory of Open Access Journals (Sweden)

    Punith K

    2008-01-01

    Full Text Available Research Question: Is LQAS technique better than cluster sampling technique in terms of resources to evaluate the immunization coverage in an urban area? Objective: To assess and compare the lot quality assurance sampling against cluster sampling in the evaluation of primary immunization coverage. Study Design: Population-based cross-sectional study. Study Setting: Areas under Mathikere Urban Health Center. Study Subjects: Children aged 12 months to 23 months. Sample Size: 220 in cluster sampling, 76 in lot quality assurance sampling. Statistical Analysis: Percentages and Proportions, Chi square Test. Results: (1 Using cluster sampling, the percentage of completely immunized, partially immunized and unimmunized children were 84.09%, 14.09% and 1.82%, respectively. With lot quality assurance sampling, it was 92.11%, 6.58% and 1.31%, respectively. (2 Immunization coverage levels as evaluated by cluster sampling technique were not statistically different from the coverage value as obtained by lot quality assurance sampling techniques. Considering the time and resources required, it was found that lot quality assurance sampling is a better technique in evaluating the primary immunization coverage in urban area.

  4. Improved sample preparation and counting techniques for enhanced tritium measurement sensitivity

    Science.gov (United States)

    Moran, J.; Aalseth, C.; Bailey, V. L.; Mace, E. K.; Overman, C.; Seifert, A.; Wilcox Freeburg, E. D.

    2015-12-01

    Tritium (T) measurements offer insight to a wealth of environmental applications including hydrologic tracking, discerning ocean circulation patterns, and aging ice formations. However, the relatively short half-life of T (12.3 years) limits its effective age dating range. Compounding this limitation is the decrease in atmospheric T content by over two orders of magnitude (from 1000-2000 TU in 1962 to testing in the 1960's. We are developing sample preparation methods coupled to direct counting of T via ultra-low background proportional counters which, when combined, offer improved T measurement sensitivity (~4.5 mmoles of H2 equivalent) and will help expand the application of T age dating to smaller sample sizes linked to persistent environmental questions despite the limitations above. For instance, this approach can be used to T date ~ 2.2 mmoles of CH4 collected from sample-limited systems including microbial communities, soils, or subsurface aquifers and can be combined with radiocarbon dating to distinguish the methane's formation age from C age in a system. This approach can also expand investigations into soil organic C where the improved sensitivity will permit resolution of soil C into more descriptive fractions and provide direct assessments of the stability of specific classes of organic matter in soils environments. We are employing a multiple step sample preparation system whereby organic samples are first combusted with resulting CO2 and H2O being used as a feedstock to synthesize CH4. This CH4 is mixed with Ar and loaded directly into an ultra-low background proportional counter for measurement of T β decay in a shallow underground laboratory. Analysis of water samples requires only the addition of geologic CO2 feedstock with the sample for methane synthesis. The chemical nature of the preparation techniques enable high sample throughput with only the final measurement requiring T decay with total sample analysis time ranging from 2 -5 weeks

  5. Sample preparation for large-scale bioanalytical studies based on liquid chromatographic techniques.

    Science.gov (United States)

    Medvedovici, Andrei; Bacalum, Elena; David, Victor

    2018-01-01

    Quality of the analytical data obtained for large-scale and long term bioanalytical studies based on liquid chromatography depends on a number of experimental factors including the choice of sample preparation method. This review discusses this tedious part of bioanalytical studies, applied to large-scale samples and using liquid chromatography coupled with different detector types as core analytical technique. The main sample preparation methods included in this paper are protein precipitation, liquid-liquid extraction, solid-phase extraction, derivatization and their versions. They are discussed by analytical performances, fields of applications, advantages and disadvantages. The cited literature covers mainly the analytical achievements during the last decade, although several previous papers became more valuable in time and they are included in this review. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Decomposition and (importance) sampling techniques for multi-stage stochastic linear programs

    Energy Technology Data Exchange (ETDEWEB)

    Infanger, G.

    1993-11-01

    The difficulty of solving large-scale multi-stage stochastic linear programs arises from the sheer number of scenarios associated with numerous stochastic parameters. The number of scenarios grows exponentially with the number of stages and problems get easily out of hand even for very moderate numbers of stochastic parameters per stage. Our method combines dual (Benders) decomposition with Monte Carlo sampling techniques. We employ importance sampling to efficiently obtain accurate estimates of both expected future costs and gradients and right-hand sides of cuts. The method enables us to solve practical large-scale problems with many stages and numerous stochastic parameters per stage. We discuss the theory of sharing and adjusting cuts between different scenarios in a stage. We derive probabilistic lower and upper bounds, where we use importance path sampling for the upper bound estimation. Initial numerical results turned out to be promising.

  7. Texture investigation in aluminium and iron - silicon samples by neutron diffraction technique

    International Nuclear Information System (INIS)

    Pugliese, R.; Yamasaki, J.M.

    1988-09-01

    By means of the neutron diffraction technique the texture of 5% and 98% rolled-aluminium and of iron-silicon steel used in the core of electric transformers, have been determined. The measurements were performed by using a neutron diffractometer installed at the IEA-R1 Nuclear Research Reactor, in the Beam-Hole n 0 . 6. To avoid corrections such as neutron absorption and sample luminosity the geometric form of the samples were approximated to spheric or octagonal prism, and its dimensions do not exceed that of the neutron beam. The texture of the samples were analysed with the help of a computer programme that analyses the intensity of the diffracted neutron beam and plot the pole figures. (author) [pt

  8. Use of fission track analysis technique for the determination of MicroBequerel level of {sup 239}Pu in urine samples from radiation workers handling MOX fuel

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, J.R., E-mail: yadav_jogendra@rediffmail.co [Health Physics Laboratory, Health Physics Division, BARC, Tarapur 401502 (India); Rao, D.D.; Kumar, Ranjeet [Health Physics Laboratory, Health Physics Division, BARC, Tarapur 401502 (India); Aggarwal, S.K. [Fuel chemistry Division, BARC, Trombay, Mumbai 400085 (India)

    2011-07-15

    Fission track analysis (FTA) technique for the determination of {sup 239}Pu excreted through urine has been standardized using blank samples, tracer and {sup 239}Pu spikes. Double stage anion exchange separation protocol has been applied and an average radiochemical recovery of {sup 239}Pu of 18% was obtained. An average track registration efficiency of 11 tracks per {mu}Bq of {sup 239}Pu, irradiated to 0.35x10{sup 17} neutron fluence was established. Reagent blank urine samples from 11 controlled subjects were analyzed by FTA and an average of 149{+-}14 tracks was obtained. Minimum detectable activity of 34 {mu}Bq L{sup -1} of urine sample was obtained and will be useful for monitoring chronic exposure cases handling MOX fuel.

  9. Water stable isotope measurements of Antarctic samples by means of IRMS and WS-CRDS techniques

    Science.gov (United States)

    Michelini, Marzia; Bonazza, Mattia; Braida, Martina; Flora, Onelio; Dreossi, Giuliano; Stenni, Barbara

    2010-05-01

    In the last years in the scientific community there has been an increasing interest for the application of stable isotope techniques to several environmental problems such as drinking water safeguarding, groundwater management, climate change, soils and paleoclimate studies etc. For example, the water stable isotopes, being natural tracers of the hydrological cycle, have been extensively used as tools to characterize regional aquifers and to reconstruct past temperature changes from polar ice cores. Here the need for improvements in analytical techniques: the high request for information calls for technologies that can offer a great quantity of analyses in short times and with low costs. Furthermore, sometimes it is difficult to obtain big amount of samples (as is the case for Antarctic ice cores or interstitial water) preventing the possibility to replicate the analyses. Here, we present oxygen and hydrogen measurements performed on water samples covering a big range of isotopic values (from very negative antarctic precipitation to mid-latitude precipitation values) carried out with both the conventional Isotope Ratio Mass Spectrometry (IRMS) technique and with a new method based on laser absorption techniques, the Wavelenght Scanned Cavity Ringdown Spectroscopy (WS-CRDS). This study is focusing on improving the precision of the measurements carried out with WS-CRDS in order to extensively apply this method to Antarctic ice core paleoclimate studies. The WS-CRDS is a variation of the CRDS developed in 1988 by O'Keef and Deacon. In CRDS a pulse of light goes through a box with high reflective inner surfaces; when there is no sample in the box the light beam doesn't find any obstacle in its path, but the reflectivity of the walls is not perfect so eventually there will be an absorption of the light beam; when the sample is injected in the box there is absorption and the difference between the time of absorption without and with sample is proportional to the quantity

  10. Determination of trace elements in plant samples using XRF, PIXE and ICP-OES techniques

    International Nuclear Information System (INIS)

    Ahmed, Hassan Elzain Hassan

    2014-07-01

    The purpose of this study is to determine trace element concentration (Ca, Cu, Cr, K,Fe, Mn,Sr, and Za) in some sudanese wild plants namely, Ziziphus Abyssinica and Grewia Tenax. X-ray fluorescence ( X RF), particle-induced x-ray emission ( PIXE) and inductively coupled plasma-optical emission spectroscopy (ICP-OES) techniques were used for element determination. A series of plants standard references materials were used to check the reliability of the different employed techniques as well as to estimate possible factors for correcting the concentration of some elements that deviated significantly from their actual concentration. The results showed that, X RF, PIXE and ICP-OES are equally competitive methods for measuring Ca,K, Fe, Sr and Zn elements. Unlikely to ICP-OES seems to be superior techniques tend to be appropriate methods for Cu determination in plant samples however, for Mn element PIXE and ICP-OES are advisable techniques for measuring this element rather than X RF method. On the other hand, ICP-OES seems to be the superior techniques over PIXE and X RF methods for Cr and Ni determination in plant samples. The effect of geographical location on trace elements concentration in plants has been examined through determination of element in different species of Grewia Tenax than collected from different location. Most of measured elements showed similarity indicating there is no significant impact of locations on the difference of element contents. In addition, two plants with different genetic families namely, Ziziphus Spina Christi and Ziziphus Abyssinica were collected from the same location and screened for their trace element content. It was found that there were no difference between the two plants for Ca, K, Cu, Fe, and Sr element. However, significant variations were observed for Mn and Zn concentrations implying the possibility of using of those two elements for plant taxonomy purposes.(Author)

  11. Neutron activation analysis technique and X-ray fluorescence in bovine liver sample

    International Nuclear Information System (INIS)

    Maihara, V.A.; Favaro, D.I.T.; Vasconcellos, M.B.A.; Sato, I.M.; Salvador, V.L.

    2002-01-01

    Many analytical techniques have been used in food and diet analysis in order to determine a great number of nutritional elements, ranging from percentage to ng g -1 , with high sensitivity and accuracy. Instrumental Neutron activation Analysis (INAA) has been employed to certificate many trace elements in biological reference materials. More recently, the X-Ray Fluorescence (FRX-WD) has been also used to determine some essential elements in food samples. The INAA has been applied in nutrition studies in our laboratory at IPEN since the 80 s. For the development of analytical methodologies the use of the reference materials with the same characteristics of the sample analyzed is essential. Several Brazilian laboratories do not have conditions to use these materials due their high cost.In this paper preliminary results of commercial bovine liver sample analyses obtained by INAA and WD-XRF methods are presented. This sample was prepared to be a Brazilian candidate of reference material for a group of laboratories participating in a research project sponsored by FAPESP. The concentrations of some elements like Cl, K, Na, P, S and trace elements Br, Ca, Co, Cu, Fe, Mg, Mn, Mo, Rb, Se and Zn were determined by INAA and WD-XFR. For validation methodology of both techniques, NIST SRM 1577b Bovine Liver reference material was analyzed and the detection limits were calculated. The concentrations of elements determined by both analytical techniques were compared by using the Student's t-test and for Cl, Cu, Fe, K, Mg, Na, Rn and Zn the results do show no statistical difference for 95% significance level. (author)

  12. Evaluation of primary immunization coverage of infants under universal immunization programme in an urban area of bangalore city using cluster sampling and lot quality assurance sampling techniques.

    Science.gov (United States)

    K, Punith; K, Lalitha; G, Suman; Bs, Pradeep; Kumar K, Jayanth

    2008-07-01

    Is LQAS technique better than cluster sampling technique in terms of resources to evaluate the immunization coverage in an urban area? To assess and compare the lot quality assurance sampling against cluster sampling in the evaluation of primary immunization coverage. Population-based cross-sectional study. Areas under Mathikere Urban Health Center. Children aged 12 months to 23 months. 220 in cluster sampling, 76 in lot quality assurance sampling. Percentages and Proportions, Chi square Test. (1) Using cluster sampling, the percentage of completely immunized, partially immunized and unimmunized children were 84.09%, 14.09% and 1.82%, respectively. With lot quality assurance sampling, it was 92.11%, 6.58% and 1.31%, respectively. (2) Immunization coverage levels as evaluated by cluster sampling technique were not statistically different from the coverage value as obtained by lot quality assurance sampling techniques. Considering the time and resources required, it was found that lot quality assurance sampling is a better technique in evaluating the primary immunization coverage in urban area.

  13. Comparison of lung tumor motion measured using a model-based 4DCT technique and a commercial protocol.

    Science.gov (United States)

    O'Connell, Dylan; Shaverdian, Narek; Kishan, Amar U; Thomas, David H; Dou, Tai H; Lewis, John H; Lamb, James M; Cao, Minsong; Tenn, Stephen; Percy, Lee P; Low, Daniel A

    2017-11-11

    To compare lung tumor motion measured with a model-based technique to commercial 4-dimensional computed tomography (4DCT) scans and describe a workflow for using model-based 4DCT as a clinical simulation protocol. Twenty patients were imaged using a model-based technique and commercial 4DCT. Tumor motion was measured on each commercial 4DCT dataset and was calculated on model-based datasets for 3 breathing amplitude percentile intervals: 5th to 85th, 5th to 95th, and 0th to 100th. Internal target volumes (ITVs) were defined on the 4DCT and 5th to 85th interval datasets and compared using Dice similarity. Images were evaluated for noise and rated by 2 radiation oncologists for artifacts. Mean differences in tumor motion magnitude between commercial and model-based images were 0.47 ± 3.0, 1.63 ± 3.17, and 5.16 ± 4.90 mm for the 5th to 85th, 5th to 95th, and 0th to 100th amplitude intervals, respectively. Dice coefficients between ITVs defined on commercial and 5th to 85th model-based images had a mean value of 0.77 ± 0.09. Single standard deviation image noise was 11.6 ± 9.6 HU in the liver and 6.8 ± 4.7 HU in the aorta for the model-based images compared with 57.7 ± 30 and 33.7 ± 15.4 for commercial 4DCT. Mean model error within the ITV regions was 1.71 ± 0.81 mm. Model-based images exhibited reduced presence of artifacts at the tumor compared with commercial images. Tumor motion measured with the model-based technique using the 5th to 85th percentile breathing amplitude interval corresponded more closely to commercial 4DCT than the 5th to 95th or 0th to 100th intervals, which showed greater motion on average. The model-based technique tended to display increased tumor motion when breathing amplitude intervals wider than 5th to 85th were used because of the influence of unusually deep inhalations. These results suggest that care must be taken in selecting the appropriate interval during image generation when using model-based 4DCT methods. Copyright © 2017

  14. Laparoscopic colorectal surgery in learning curve: Role of implementation of a standardized technique and recovery protocol. A cohort study

    Science.gov (United States)

    Luglio, Gaetano; De Palma, Giovanni Domenico; Tarquini, Rachele; Giglio, Mariano Cesare; Sollazzo, Viviana; Esposito, Emanuela; Spadarella, Emanuela; Peltrini, Roberto; Liccardo, Filomena; Bucci, Luigi

    2015-01-01

    Background Despite the proven benefits, laparoscopic colorectal surgery is still under utilized among surgeons. A steep learning is one of the causes of its limited adoption. Aim of the study is to determine the feasibility and morbidity rate after laparoscopic colorectal surgery in a single institution, “learning curve” experience, implementing a well standardized operative technique and recovery protocol. Methods The first 50 patients treated laparoscopically were included. All the procedures were performed by a trainee surgeon, supervised by a consultant surgeon, according to the principle of complete mesocolic excision with central vascular ligation or TME. Patients underwent a fast track recovery programme. Recovery parameters, short-term outcomes, morbidity and mortality have been assessed. Results Type of resections: 20 left side resections, 8 right side resections, 14 low anterior resection/TME, 5 total colectomy and IRA, 3 total panproctocolectomy and pouch. Mean operative time: 227 min; mean number of lymph-nodes: 18.7. Conversion rate: 8%. Mean time to flatus: 1.3 days; Mean time to solid stool: 2.3 days. Mean length of hospital stay: 7.2 days. Overall morbidity: 24%; major morbidity (Dindo–Clavien III): 4%. No anastomotic leak, no mortality, no 30-days readmission. Conclusion Proper laparoscopic colorectal surgery is safe and leads to excellent results in terms of recovery and short term outcomes, even in a learning curve setting. Key factors for better outcomes and shortening the learning curve seem to be the adoption of a standardized technique and training model along with the strict supervision of an expert colorectal surgeon. PMID:25859386

  15. Use of a multigrid technique to study effects of limited sampling of heterogeneity on transport prediction

    International Nuclear Information System (INIS)

    Cole, C.R.; Foote, H.P.

    1987-02-01

    Reliable ground water transport prediction requires accurate spatial and temporal characterization of a hydrogeologic system. However, cost constraints and the desire to maintain site integrity by minimizing drilling can restrict the amount of spatial sampling that can be obtained to resolve the flow parameter variability associated with heterogeneities. This study quantifies the errors in subsurface transport predictions resulting from incomplete characterization of hydraulic conductivity heterogeneity. A multigrid technique was used to simulate two-dimensional flow velocity fields with high resolution. To obtain these velocity fields, the finite difference code MGRID, which implements a multigrid solution technique, was applied to compute stream functions on a 256-by-256 grid for a variety of hypothetical systems having detailed distributions of hydraulic conductivity. Spatial variability in hydraulic conductivity distributions was characterized by the components in the spectrum of spatial frequencies. A low-pass spatial filtering technique was applied to the base case hydraulic conductivity distribution to produce a data set with lower spatial frequency content. Arrival time curves were then calculated for filtered hydraulic conductivity distribution and compared to base case results to judge the relative importance of the higher spatial frequency components. Results indicate a progression from multimode to single-mode arrival time curves as the number and extent of distinct flow pathways are reduced by low-pass filtering. This relationship between transport predictions and spatial frequencies was used to judge the consequences of sampling the hydraulic conductivity with reduced spatial resolution. 22 refs., 17 figs

  16. A cost-effective technique for integrating personal radiation dose assessment with personal gravimetric sampling

    International Nuclear Information System (INIS)

    Strydom, R.; Rolle, R.; Van der Linde, A.

    1992-01-01

    During recent years there has been an increasing awareness internationally of radiation levels in the mining and milling of radioactive ores, including those from non-uranium mines. A major aspect of radiation control is concerned with the measurement of radiation levels and the assessment of radiation doses incurred by individual workers. Current techniques available internationally for personnel monitoring of radiation exposures are expensive and there is a particular need to reduce the cost of personal radiation monitoring in South African gold mines because of the large labour force employed. In this regard the obvious benefits of integrating personal radiation monitoring with existing personal monitoring systems already in place in South African gold mines should be exploited. A system which can be utilized for this purpose is personal gravimetric sampling. A new cost-effective technique for personal radiation monitoring, which can be fully integrated with the personal gravimetric sampling strategy being implemented on mines, has been developed in South Africa. The basic principles of this technique and its potential in South African mines are described. 9 refs., 7 figs

  17. An Electromagnetic Gauge Technique for Measuring Shocked Particle Velocity in Electrically Conductive Samples

    Science.gov (United States)

    Cheng, David; Yoshinaka, Akio

    2014-11-01

    Electromagnetic velocity (EMV) gauges are a class of film gauges which permit the direct in-situ measurement of shocked material flow velocity. The active sensing element, typically a metallic foil, requires exposure to a known external magnetic field in order to produce motional electromotive force (emf). Due to signal distortion caused by mutual inductance between sample and EMV gauge, this technique is typically limited to shock waves in non-conductive materials. In conductive samples, motional emf generated in the EMV gauge has to be extracted from the measured signal which results from the combined effects of both motional emf and voltage changes from induced currents. An electromagnetic technique is presented which analytically models the dynamics of induced current between a copper disk moving as a rigid body with constant 1D translational velocity toward an EMV gauge, where both disk and gauge are exposed to a uniform external static magnetic field. The disk is modelled as a magnetic dipole loop where its Foucault current is evaluated from the characteristics of the fields, whereas the EMV gauge is modelled as a circuit loop immersed in the field of the magnetic dipole loop, the intensity of which is calculated as a function of space and, implicitly, time. Equations of mutual induction are derived and the current induced in the EMV gauge loop is solved, allowing discrimination of the motional emf. Numerical analysis is provided for the step response of the induced EMV gauge current with respect to the Foucault current in the moving copper sample.

  18. Coherent optical adaptive technique improves the spatial resolution of STED microscopy in thick samples

    Science.gov (United States)

    Yan, Wei; Yang, Yanlong; Tan, Yu; Chen, Xun; Li, Yang; Qu, Junle; Ye, Tong

    2018-01-01

    Stimulated emission depletion microscopy (STED) is one of far-field optical microscopy techniques that can provide sub-diffraction spatial resolution. The spatial resolution of the STED microscopy is determined by the specially engineered beam profile of the depletion beam and its power. However, the beam profile of the depletion beam may be distorted due to aberrations of optical systems and inhomogeneity of specimens’ optical properties, resulting in a compromised spatial resolution. The situation gets deteriorated when thick samples are imaged. In the worst case, the sever distortion of the depletion beam profile may cause complete loss of the super resolution effect no matter how much depletion power is applied to specimens. Previously several adaptive optics approaches have been explored to compensate aberrations of systems and specimens. However, it is hard to correct the complicated high-order optical aberrations of specimens. In this report, we demonstrate that the complicated distorted wavefront from a thick phantom sample can be measured by using the coherent optical adaptive technique (COAT). The full correction can effectively maintain and improve the spatial resolution in imaging thick samples. PMID:29400356

  19. Localisation and identification of radioactive particles in solid samples by means of a nuclear track technique

    International Nuclear Information System (INIS)

    Boehnke, Antje; Treutler, Hanns-Christian; Freyer, Klaus; Schubert, Michael; Holger Weiss

    2005-01-01

    This study is aimed to develop a generally applicable methodology of investigation that can be used for the localisation of single alpha-active particles in solid samples, such as industrial dust or natural soils, sediments and rocks by autoradiography using solid-state nuclear track detectors. The developed technique allows the detection of local enrichments of alpha-emitters in any solid material. The results of such an investigation are of interest from technical, biological and environmental points of view. The idea behind the methodology is to locate the position of alpha-active spots in a sample by attaching the track detector to the sample in a defined manner, thoroughly described in the paper. The located alpha-active particles are subsequently analysed by an electron microscope and an electron microprobe. An example of the application of this methodology is also given. An ultra-fine -grained ore-processing residue, which causes serious environmental pollution in the respective mining district and thus limits possible land use and affects quality of life in the area, was examined using the described technique. The investigation revealed considerable amounts of alpha-active particles in this material

  20. Review of cleaning techniques and their effects on the chemical composition of foliar samples

    Energy Technology Data Exchange (ETDEWEB)

    Rossini Oliva, S.; Raitio, H.

    2003-07-01

    Chemical foliar analysis is a tool widely used to study tree nutrition and to monitor the impact and extent of air pollutants. This paper reviews a number of cleaning methods, and the effects of cleaning on foliar chemistry. Cleaning may include mechanical techniques such as the use of dry or moistened tissues, shaking, blowing, and brushing, or use various washing techniques with water or other solvents. Owing to the diversity of plant species, tissue differences, etc., there is no standard procedure for all kinds of samples. Analysis of uncleaned leaves is considered a good method for assessing the degree of air contamination because it provides an estimate of the element content of the deposits on leaf surfaces or when the analysis is aimed at the investigation of transfer of elements along the food chain. Sample cleaning is recommended in order (1) to investigate the transfer rate of chemical elements from soil to plants, (2) to qualify the washoff of dry deposition from foliage and (3) to separate superficially absorbed and biomass-incorporated elements. Since there is not a standard cleaning procedure for all kinds of samples and aims, it is advised to conduct a pilot study in order to be able to establish a cleaning procedure to provide reliable foliar data. (orig.)

  1. Convergence and Efficiency of Adaptive Importance Sampling Techniques with Partial Biasing

    Science.gov (United States)

    Fort, G.; Jourdain, B.; Lelièvre, T.; Stoltz, G.

    2018-04-01

    We propose a new Monte Carlo method to efficiently sample a multimodal distribution (known up to a normalization constant). We consider a generalization of the discrete-time Self Healing Umbrella Sampling method, which can also be seen as a generalization of well-tempered metadynamics. The dynamics is based on an adaptive importance technique. The importance function relies on the weights (namely the relative probabilities) of disjoint sets which form a partition of the space. These weights are unknown but are learnt on the fly yielding an adaptive algorithm. In the context of computational statistical physics, the logarithm of these weights is, up to an additive constant, the free-energy, and the discrete valued function defining the partition is called the collective variable. The algorithm falls into the general class of Wang-Landau type methods, and is a generalization of the original Self Healing Umbrella Sampling method in two ways: (i) the updating strategy leads to a larger penalization strength of already visited sets in order to escape more quickly from metastable states, and (ii) the target distribution is biased using only a fraction of the free-energy, in order to increase the effective sample size and reduce the variance of importance sampling estimators. We prove the convergence of the algorithm and analyze numerically its efficiency on a toy example.

  2. Proposal of sampling protocols to verify possible performance objectives for Campylobacter species control in Italian broiler batches

    Directory of Open Access Journals (Sweden)

    Gerardo Manfreda

    2013-04-01

    Full Text Available Campylobacteriosis represents the most important food-borne illness in the EU. Broilers, as well as poultry meat, spread the majority of strains responsible for human cases. The main aims of this study were to suggest an approach for the definition of performance objectives (POs based on prevalence and concentration of Campylobacter species (spp. in broiler carcasses; moreover, sampling plans to determine the acceptability of broiler batches at the slaughterhouses in relation to such POs were formulated. The dataset used in this study was the one regarding Italy composed during the European Food Safety Authority baseline survey which was performed in the EU in 2008. A total of 393 carcasses obtained from 393 different batches collected from 48 Italian slaughterhouses were included in the analysis. Uncertainty in prevalence and concentration of Campylobacter spp. on carcasses was quantified assuming a beta and log normal distribution. Statistical analysis and distribution fitting were performed in ModelRisk v4.3 (Monte Carlo simulation with 10,000 iterations. By taking the 50th percentile of prevalence distribution as safety limit, sampling plans were subsequently calculated basing on the binomial approach. Final values of number of samples were equal to 4 or 5 to test with qualitative analysis. Considering a limit of quantification of 10 colony forming units/g, a higher number of samples (i.e. 10-13 would be necessary to test using enumeration. An increase of the sensibility of the analytical technique should be necessary to achieve realistic and useful sampling plans based on concentration data.

  3. Low-mass molecular dynamics simulation: A simple and generic technique to enhance configurational sampling

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Yuan-Ping, E-mail: pang@mayo.edu

    2014-09-26

    Highlights: • Reducing atomic masses by 10-fold vastly improves sampling in MD simulations. • CLN025 folded in 4 of 10 × 0.5-μs MD simulations when masses were reduced by 10-fold. • CLN025 folded as early as 96.2 ns in 1 of the 4 simulations that captured folding. • CLN025 did not fold in 10 × 0.5-μs MD simulations when standard masses were used. • Low-mass MD simulation is a simple and generic sampling enhancement technique. - Abstract: CLN025 is one of the smallest fast-folding proteins. Until now it has not been reported that CLN025 can autonomously fold to its native conformation in a classical, all-atom, and isothermal–isobaric molecular dynamics (MD) simulation. This article reports the autonomous and repeated folding of CLN025 from a fully extended backbone conformation to its native conformation in explicit solvent in multiple 500-ns MD simulations at 277 K and 1 atm with the first folding event occurring as early as 66.1 ns. These simulations were accomplished by using AMBER forcefield derivatives with atomic masses reduced by 10-fold on Apple Mac Pros. By contrast, no folding event was observed when the simulations were repeated using the original AMBER forcefields of FF12SB and FF14SB. The results demonstrate that low-mass MD simulation is a simple and generic technique to enhance configurational sampling. This technique may propel autonomous folding of a wide range of miniature proteins in classical, all-atom, and isothermal–isobaric MD simulations performed on commodity computers—an important step forward in quantitative biology.

  4. MUP, CEC-DES, STRADE. Codes for uncertainty propagation, experimental design and stratified random sampling techniques

    International Nuclear Information System (INIS)

    Amendola, A.; Astolfi, M.; Lisanti, B.

    1983-01-01

    The report describes the how-to-use of the codes: MUP (Monte Carlo Uncertainty Propagation) for uncertainty analysis by Monte Carlo simulation, including correlation analysis, extreme value identification and study of selected ranges of the variable space; CEC-DES (Central Composite Design) for building experimental matrices according to the requirements of Central Composite and Factorial Experimental Designs; and, STRADE (Stratified Random Design) for experimental designs based on the Latin Hypercube Sampling Techniques. Application fields, of the codes are probabilistic risk assessment, experimental design, sensitivity analysis and system identification problems

  5. Non-destructive high-resolution thermal imaging techniques to evaluate wildlife and delicate biological samples

    International Nuclear Information System (INIS)

    Lavers, C; Franklin, P; Franklin, P; Plowman, A; Sayers, G; Bol, J; Shepard, D; Fields, D

    2009-01-01

    Thermal imaging cameras now allows routine monitoring of dangerous yet endangered wildlife in captivity. This study looks at the potential applications of radiometrically calibrated thermal data to wildlife, as well as providing parameters for future materials applications. We present a non-destructive active testing technique suitable for enhancing imagery contrast of thin or delicate biological specimens yielding improved thermal contrast at room temperature, for analysis of sample thermal properties. A broad spectrum of animals is studied with different textured surfaces, reflective and emissive properties in the infra red part of the electromagnetic spectrum. Some surface features offer biomimetic materials design opportunities.

  6. A novel in-situ sampling and VFA sensor technique for anaerobic systems

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær

    2002-01-01

    A key information for understanding and controlling the anaerobic biogas process is the concentration of Volatile Fatty Acids (VFA). However, access to this information has so far been limited to off-line measurements by manual time and labour consuming methods. We have developed a new technique ...... than 1000 samples on both a fullscale biogas plant and lab-scale reactors. The measuring range covers specific measurements of acetate, propionate, iso-/n-butyrate and iso-/n-valerate from 0.1 to 50 mM (6–3,000 mg)....

  7. Investigation of an egyptian phosphate ore sample by neutron activation analysis technique

    International Nuclear Information System (INIS)

    Eissa, E.A.; Aly, R.A.; Rofail, N.B.; Hassan, A.M.

    1995-01-01

    A domestic phosphate ore sample has been analysed by means of prompt and delayed gamma-ray spectrometry following the activation by thermal neutron capture technique. The rabbit pneumatic transfer system (RPTS), long irradiation facility and two Pu/Be (2,5 Ci each) neutron sources set-Pu for prompt (n,gamma) were applied. The high purity germanium (HPGe) gamma-ray spectrometer with a personal computer analyzer (PCA) system were used for spectrum measurements. Programmes on the VAX computer were utilized for estimating the elemental concentrations of 22 out of 36 elements identified in this work. 2 tabs

  8. Non-destructive high-resolution thermal imaging techniques to evaluate wildlife and delicate biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Lavers, C; Franklin, P; Franklin, P; Plowman, A; Sayers, G; Bol, J; Shepard, D; Fields, D, E-mail: brnc-radarcomms1@nrta.mod.u [Sensors Team, Plymouth University at Britannia Royal Naval College, Dartmouth, Devon (United Kingdom) and Paignton Zoological Park, Paignton, Devon (United Kingdom); Thermal Wave Imaging, Inc., 845 Livernoise St, Ferndale, MI (United States); Buckfast Butterfly and Otter Sanctuary, Buckfast, Devon (United Kingdom)

    2009-07-01

    Thermal imaging cameras now allows routine monitoring of dangerous yet endangered wildlife in captivity. This study looks at the potential applications of radiometrically calibrated thermal data to wildlife, as well as providing parameters for future materials applications. We present a non-destructive active testing technique suitable for enhancing imagery contrast of thin or delicate biological specimens yielding improved thermal contrast at room temperature, for analysis of sample thermal properties. A broad spectrum of animals is studied with different textured surfaces, reflective and emissive properties in the infra red part of the electromagnetic spectrum. Some surface features offer biomimetic materials design opportunities.

  9. Analysis of boron utilization in sample preparation for microorganisms detection by neutron radiography technique

    International Nuclear Information System (INIS)

    Wacha, Reinaldo; Crispim, Verginia R.

    2000-01-01

    The neutron radiography technique applied to the microorganisms detection is the study of a new and faster alternative for diagnosis of infectious means. This work presents the parameters and the effects involved in the use of the boron as a conversion agent, that convert neutrons in a particles, capable ones of generating latent tracks in a solid state nuclear tracks detector, CR-39. The collected samples are doped with the boron by the incubation method, propitiating an interaction microorganisms/boron, that will guarantee the identification of the images of those microorganisms, through your morphology. (author)

  10. A rapid method of radium-226 analysis in water samples using an alpha spectroscopic technique

    International Nuclear Information System (INIS)

    Lim, T.P.

    1981-01-01

    A fast, reliable and accurate method for radium-226 determination in environmental water samples has been devised, using an alpha spectroscopic technique. The correlation between barium-133 and radium-226 in the barium-radium sulphate precipitation mechanism was studied and in the limited experimental recovery range, the coefficient of correlation was r = 0.986. A self-absorption study for various barium carrier concentrations was also undertaken to obtain the least broadening of alpha energy line widths. An optimum value of 0.3 mg barium carrier was obtained for chemical recovery in the range of 85 percent. (auth)

  11. TRAN-STAT: statistics for environmental studies, Number 22. Comparison of soil-sampling techniques for plutonium at Rocky Flats

    International Nuclear Information System (INIS)

    Gilbert, R.O.; Bernhardt, D.E.; Hahn, P.B.

    1983-01-01

    A summary of a field soil sampling study conducted around the Rocky Flats Colorado plant in May 1977 is preseted. Several different soil sampling techniques that had been used in the area were applied at four different sites. One objective was to comparethe average 239 - 240 Pu concentration values obtained by the various soil sampling techniques used. There was also interest in determining whether there are differences in the reproducibility of the various techniques and how the techniques compared with the proposed EPA technique of sampling to 1 cm depth. Statistically significant differences in average concentrations between the techniques were found. The differences could be largely related to the differences in sampling depth-the primary physical variable between the techniques. The reproducibility of the techniques was evaluated by comparing coefficients of variation. Differences between coefficients of variation were not statistically significant. Average (median) coefficients ranged from 21 to 42 percent for the five sampling techniques. A laboratory study indicated that various sample treatment and particle sizing techniques could increase the concentration of plutonium in the less than 10 micrometer size fraction by up to a factor of about 4 compared to the 2 mm size fraction

  12. Data quality and feasibility of the Experience Sampling Method across the spectrum of severe psychiatric disorders: a protocol for a systematic review and meta-analysis.

    Science.gov (United States)

    Vachon, Hugo; Rintala, Aki; Viechtbauer, Wolfgang; Myin-Germeys, Inez

    2018-01-18

    Due to a number of methodological advantages and theoretical considerations, more and more studies in clinical psychology research employ the Experience Sampling Method (ESM) as a data collection technique. Despite this growing interest, the absence of methodological guidelines related to the use of ESM has resulted in a large heterogeneity of designs while the potential effects of the design itself on the response behavior of the participants remain unknown. The objectives of this systematic review are to investigate the associations between the design characteristics and the data quality and feasibility of studies relying on ESM in severe psychiatric disorders. We will search for all published studies using ambulatory assessment with patients suffering from major depressive disorder, bipolar disorder, and psychotic disorder or individuals at high risk for these disorders. Electronic database searches will be performed in PubMed and Web of Science with no restriction on the publication date. Two reviewers will independently screen original studies in a title/abstract phase and a full-text phase based on the inclusion criteria. The information related to the design and sample characteristics, data quality, and feasibility will be extracted. We will provide results in terms of a descriptive synthesis, and when applicable, a meta-analysis of the findings will be conducted. Our results will attempt to highlight how the feasibility and data quality of ambulatory assessment might be related to the methodological characteristics of the study designs in severe psychiatric disorders. We will discuss these associations in different subsamples if sufficient data are available and will examine limitations in the reporting of the methods of ambulatory studies in the current literature. The protocol for this systematic review was registered on PROSPERO (PROSPERO 2017: CRD42017060322 ) and is available in full on the University of York website ( http://www.crd

  13. Three Proposed Compendia for Genesis Solar Wind Samples: Science Results, Collector Materials Characterization and Cleaning Techniques

    Science.gov (United States)

    Allton, J. H.; Calaway, M. J.; Nyquist, L. E.; Jurewicz, A. J. G.; Burnett, D. S.

    2018-01-01

    Final Paper and not the abstract is attached. Introduction: Planetary material and cosmochemistry research using Genesis solar wind samples (including the development and implementation of cleaning and analytical techniques) has matured sufficiently that compilations on several topics, if made publically accessible, would be beneficial for researchers and reviewers. We propose here three compendia based on content, organization and source of documents (e.g. published peer-reviewed, published, internal memos, archives). For planning purposes, suggestions are solicited from potential users of Genesis solar wind samples for the type of science content and/or organizational style that would be most useful to them. These compendia are proposed as living documents, periodically updated. Similar to the existing compendia described below, the curation compendia are like library or archival finding aids, they are guides to published or archival documents and should not be cited as primary sources.

  14. Comparison of Different Sample Preparation Protocols Reveals Lysis Buffer-Specific Extraction Biases in Gram-Negative Bacteria and Human Cells.

    Science.gov (United States)

    Glatter, Timo; Ahrné, Erik; Schmidt, Alexander

    2015-11-06

    We evaluated different in-solution and FASP-based sample preparation strategies for absolute protein quantification. Label-free quantification (LFQ) was employed to compare different sample preparation strategies in the bacterium Pseudomonas aeruginosa and human embryonic kidney cells (HEK), and organismal-specific differences in general performance and enrichment of specific protein classes were noted. The original FASP protocol globally enriched for most proteins in the bacterial sample, whereas the sodium deoxycholate in-solution strategy was more efficient with HEK cells. Although detergents were found to be highly suited for global proteome analysis, higher intensities were obtained for high-abundant nucleic acid-associated protein complexes, like the ribosome and histone proteins, using guanidine hydrochloride. Importantly, we show for the first time that the observable total proteome mass of a sample strongly depends on the sample preparation protocol, with some protocols resulting in a significant underestimation of protein mass due to incomplete protein extraction of biased protein groups. Furthermore, we demonstrate that some of the observed abundance biases can be overcome by incorporating a nuclease treatment step or, alternatively, a correction factor for complementary sample preparation approaches.

  15. Effect of variable rates of daily sampling of fly larvae on decomposition and carrion insect community assembly: implications for forensic entomology field study protocols.

    Science.gov (United States)

    Michaud, Jean-Philippe; Moreau, Gaétan

    2013-07-01

    Experimental protocols in forensic entomology successional field studies generally involve daily sampling of insects to document temporal changes in species composition on animal carcasses. One challenge with that method has been to adjust the sampling intensity to obtain the best representation of the community present without affecting the said community. To this date, little is known about how such investigator perturbations affect decomposition-related processes. Here, we investigated how different levels of daily sampling of fly eggs and fly larvae affected, over time, carcass decomposition rate and the carrion insect community. Results indicated that a daily sampling of forensic entomology successional field studies.

  16. Issues in the analyze of low content gold mining samples by fire assay technique

    Science.gov (United States)

    Cetean, Valentina

    2016-04-01

    The classic technique analyze of samples with low gold content - below 0.1 g/t (=100 ppb = parts per billion), either ore or gold sediments, involves the preparation of sample by fire assay extraction, followed by the chemical attack with aqua regia (hydrochloric and nitric acid) and measuring the gold content by atomic absorption spectrometry or inductively coupled mass spectrometry. The issues raised by this analysis are well known for the world laboratories, commercial or research ones. The author's knowledge regarding this method of determining the gold content, accumulated in such laboratory from Romania (with more than 40 years of experience, even if not longer available from 2014) confirms the obtaining of reliable results required a lot of attention, amount of work and the involving of an experienced fire assayer specialist. The analytical conclusion for a research laboratory is that most reliable and statistically valid results are till reached for samples with more than 100 ppb gold content; the degree of confidence below this value is lower than 90%. Usually, for samples below 50 ppb, it does not exceed 50-70 %, unless without very strictly control of each stage, that involve additional percentage of hours allocated for successive extracting tests and knowing more precisely the other compounds that appear in the sample (Cu, Sb, As, sulfur / sulphides, Te, organic matter, etc.) or impurities. The most important operation is the preparation, namely: - grinding and splitting of sample (which can cause uneven distribution of gold flakes in the double samples for analyzed); - pyro-metallurgical recovery of gold = fire assay stage, involving the more precise temperature control in furnace during all stages (fusion and cupellation) and adjusting of the fire assay flux components to produce a successful fusion depending of the sample matrix and content; - reducing the sample weight to decrease the amount of impurities that can be concentrated in the lead button

  17. A novel non-invasive diagnostic sampling technique for cutaneous leishmaniasis.

    Directory of Open Access Journals (Sweden)

    Yasaman Taslimi

    2017-07-01

    Full Text Available Accurate diagnosis of cutaneous leishmaniasis (CL is important for chemotherapy and epidemiological studies. Common approaches for Leishmania detection involve the invasive collection of specimens for direct identification of amastigotes by microscopy and the culturing of promastigotes from infected tissues. Although these techniques are highly specific, they require highly skilled health workers and have the inherent risks of all invasive procedures, such as pain and risk of bacterial and fungal super-infection. Therefore, it is essential to reduce discomfort, potential infection and scarring caused by invasive diagnostic approaches especially for children. In this report, we present a novel non-invasive method, that is painless, rapid and user-friendly, using sequential tape strips for sampling and isolation of DNA from the surface of active and healed skin lesions of CL patients. A total of 119 patients suspected of suffering from cutaneous leishmaniasis with different clinical manifestations were recruited and samples were collected both from their lesions and from uninfected areas. In addition, 15 fungal-infected lesions and 54 areas of healthy skin were examined. The duration of sampling is short (less than one minute and species identification by PCR is highly specific and sensitive. The sequential tape stripping sampling method is a sensitive, non-invasive and cost-effective alternative to traditional diagnostic assays and it is suitable for field studies as well as for use in health care centers.

  18. Separation of arsenic species by capillary electrophoresis with sample-stacking techniques

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zu Liang; Naidu, Ravendra [Adelaide Laboratory, CSIRO Land and Water, PMB2, 5064, Glen Osmond, SA (Australia); Lin, Jin-Ming [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 100085, Beijing (China)

    2003-03-01

    A simple capillary zone electrophoresis procedure was developed for the separation of arsenic species (AsO{sub 2}{sup 2-}, AsO{sub 4}{sup 2-}, and dimethylarsinic acid, DMA). Both counter-electroosmotic and co-electroosmotic (EOF) modes were investigated for the separation of arsenic species with direct UV detection at 185 nm using 20 mmol L{sup -1} sodium phosphate as the electrolyte. The separation selectivity mainly depends on the separation modes and electrolyte pH. Inorganic anions (Cl{sup -}, NO{sub 2}{sup -}, NO{sub 3}{sup -} and SO{sub 4}{sup 2-}) presented in real samples did not interfere with arsenic speciation in either separation mode. To improve the detection limits, sample-stacking techniques, including large-volume sample stacking (LVSS) and field-amplified sample injection (FASI), were investigated for the preconcentration of As species in co-CZE mode. Less than 1 {mu}mol L{sup -1} of detection limits for As species were achieved using FASI. The proposed method was demonstrated for the separation and detection of As species in water. (orig.)

  19. Toxoplasma gondii and pre-treatment protocols for polymerase chain reaction analysis of milk samples: a field trial in sheep from Southern Italy

    Directory of Open Access Journals (Sweden)

    Alice Vismarra

    2017-02-01

    Full Text Available Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii. Ingestion of raw milk has been suggested as a risk for transmission to humans. Here the authors evaluated pre-treatment protocols for DNA extraction on T. gondii tachyzoite-spiked sheep milk with the aim of identifying the method that resulted in the most rapid and reliable polymerase chain reaction (PCR positivity. This protocol was then used to analyse milk samples from sheep of three different farms in Southern Italy, including real time PCR for DNA quantification and PCR-restriction fragment length polymorphism for genotyping. The pre-treatment protocol using ethylenediaminetetraacetic acid and Tris-HCl to remove casein gave the best results in the least amount of time compared to the others on spiked milk samples. One sample of 21 collected from sheep farms was positive on one-step PCR, real time PCR and resulted in a Type I genotype at one locus (SAG3. Milk usually contains a low number of tachyzoites and this could be a limiting factor for molecular identification. Our preliminary data has evaluated a rapid, cost-effective and sensitive protocol to treat milk before DNA extraction. The results of the present study also confirm the possibility of T. gondii transmission through consumption of raw milk and its unpasteurised derivatives.

  20. Solving mercury (Hg) speciation in soil samples by synchrotron X-ray microspectroscopic techniques.

    Science.gov (United States)

    Terzano, Roberto; Santoro, Anna; Spagnuolo, Matteo; Vekemans, Bart; Medici, Luca; Janssens, Koen; Göttlicher, Jörg; Denecke, Melissa A; Mangold, Stefan; Ruggiero, Pacifico

    2010-08-01

    Direct mercury (Hg) speciation was assessed for soil samples with a Hg concentration ranging from 7 up to 240 mg kg(-1). Hg chemical forms were identified and quantified by sequential extractions and bulk- and micro-analytical techniques exploiting synchrotron generated X-rays. In particular, microspectroscopic techniques such as mu-XRF, mu-XRD and mu-XANES were necessary to solve bulk Hg speciation, in both soil fractions soil samples were metacinnabar (beta-HgS), cinnabar (alpha-HgS), corderoite (Hg(3)S(2)Cl(2)), and an amorphous phase containing Hg bound to chlorine and sulfur. The amount of metacinnabar and amorphous phases increased in the fraction soil components was observed. All the observed Hg-species originated from the slow weathering of an inert Hg-containing waste material (K106, U.S. EPA) dumped in the area several years ago, which is changing into a relatively more dangerous source of pollution. Copyright 2010 Elsevier Ltd. All rights reserved.

  1. Sample preparation technique for transmission electron microscopy anodized Al-Li-SiC metal matrix composite

    International Nuclear Information System (INIS)

    Shahid, M.; Thomson, G.E.

    1997-01-01

    Along with improved mechanical properties, metal matrix composites (MMC) have a disadvantage of enhanced corrosion susceptibility in aggressive environments. Recent studies on corrosion behaviour of an Al-alloy 8090/SiC MMC, revealed considerably high corrosion rates of the MMC in near neutral solutions containing chloride ions. Anodizing is one of the potential surface treatment for the MMC to provide protective coating against corrosion. The surface and cross section of the anodized MMC can easily be observed using scanning electron microscope. The anodizing behaviour of the MMC can be understood further if the anodized cross section in examined under transmission electron microscope (TEM). However, it is relatively difficult to prepare small (3 mm diameter) electron transparent specimens of the MMC supporting an anodic film. In the present study a technique has been developed for preparing thin electron transparent specimens of the anodized MMC. This technique employed conventional ion beam thinning process but the preparation of small discs was a problem. A MMMC consisting of Al-alloy 8090 with 20 % (by weight) SiC particulate with an average size of 5 Mu m, was anodized and observed in TEM after preparing the samples using the above mentioned techniques. (author)

  2. Endodontic pathogens causing deep neck space infections: clinical impact of different sampling techniques and antibiotic susceptibility.

    Science.gov (United States)

    Poeschl, Paul W; Crepaz, Valentina; Russmueller, Guenter; Seemann, Rudolf; Hirschl, Alexander M; Ewers, Rolf

    2011-09-01

    The aims of the present study were to compare microbial populations in patients suffering from deep neck space abscesses caused by primary endodontic infections by sampling the infections with aspiration or swabbing techniques and to determine the susceptibility rates of the isolated bacteria to commonly used antibiotics. A total of 89 patients with deep neck space abscesses caused by primary endodontic infections requiring extraoral incision and drainage under general anesthesia were included. Either aspiration or swabbing was used to sample microbial pus specimens. The culture of the microbial specimens and susceptibility testing were performed following standard procedures. A total of 142 strains were recovered from 76 patients. In 13 patients, no bacteria were found. The predominant bacteria observed were streptococci (36%), staphylococci (13%), Prevotella (8%), and Peptostreptococcus (6%). A statistically significant greater number of obligate anaerobes were found in the aspiration group. The majority of patients presented a mixed aerobic-anaerobic population of bacterial flora (62%). The antibiotic resistance rates for the predominant bacteria were 10% for penicillin G, 9% for amoxicillin, 0% for amoxicillin clavulanate, 24% for clindamycin, and 24% for erythromycin. The results of our study indicated that a greater number of anaerobes were found when sampling using the aspiration technique. Penicillin G and aminopenicillins alone are not always sufficient for the treatment of severe deep neck space abscesses; beta-lactamase inhibitor combinations are more effective. Bacteria showed significant resistant rates to clindamycin. Thus, its single use in penicillin-allergic patients has to be carefully considered. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. Application of neutron activation analysis technique in elemental determination of lichen samples

    International Nuclear Information System (INIS)

    Djoko Prakoso Dwi Atmodjo; Syukria Kurniawati; Woro Yatu Niken Syahfitri; Nana Suherman; Dadang Supriatna

    2010-01-01

    Lichen is one of the biological materials as pollution monitor that can give information about level, direction, and history of various pollutants in environment. Small sample weights and elemental content of lichens is on the order of ppm, so that its characterization requires advanced analytical techniques that has high sensitivity and capable of analyzing samples with weight of - 25 mg, such as neutron activation analysis. In this research, determination of elements was done in lichen samples obtained from Kiaracondong and Holis areas in Bandung city, to understanding the difference of industrial exposure level on surrounding environment. Samples were irradiated in RSG GA Siwabessy, Serpong, at 15 MW for 1-2 and 60 minutes for short irradiation and long irradiation, respectively. The samples were then counted using HPGe detector with GENIE 2000 software. The level of element in lichen for Kiaracondong area were Co, Cr, Cs, Fe, Mg, Mn, Sb, Sc, and V in the range of 0.55-0.86, 1.47-2.57, 0.87-1.19, 540-1005, 949-1674, 34.91-45.94, 0.08-0.14, 0.16-0.31, and ≤ 2.33 mg/kg, respectively, while for Holis area were 1.04-2.37, 4.41-10.36, 0.41-0.89, 3166-709, 1131-1422, 40.97-72.51, 0.33-0.50, 0.98-2.18, and 5.30-13.05 mg/kg respectively. From these results, it is known that pollution exposure from the semi industrial area Holis provide greater influence than in the semi industrial area Kiaracondong. (author)

  4. Detecting Organic Compounds Released from Iron Oxidizing Bacteria using Sample Analysis at Mars (SAM) Like Instrument Protocols

    Science.gov (United States)

    Glavin, D. P.; Popa, R.; Martin, M. G.; Freissinet, C.; Fisk, M. R.; Dworkin, J. P.; Mahaffy, P. R.

    2012-01-01

    Mars is a planet of great interest for Astrobiology since its past environmental conditions are thought to have been favourable for the emergence life. At present, the Red Planet is extremely cold and dry and the surface is exposed to intense UV and ionizing radiation, conditions generally considered to be incompatible with life as we know it on Earth. It was proposed that the shallow subsurface of Mars, where temperatures can be above freezing and liquid water can exist on rock surfaces, could harbor chemolithoautotrophic bacteria such as the iron oxidizing microorganism Pseudomonas sp. HerB. The Mars Science Laboratory (MSL) mission will provide the next opportunity to carry out in situ measurements for organic compounds of possible biological origin on Mars. One instrument onboard MSL, called the Sample Analysis at Mars (SAM) instrument suite, will carry out a broad and sensitive search for organic compounds in surface samples using either high temperature pyrolysis or chemical extraction followed by gas chromatography mass spectrometry. We present gas chromatograph mass spectrometer (GC/MS) data on crushed olivine rock powders that have been inoculated with Pseudomonas sp. HerB at different concentrations ranging from approx 10(exp 2) to 10(exp 7) cells per gram. The inoculated olivine samples were heated under helium carrier gas flow at 500 C and the pyrolysis products concentrated using a SAM-like hydrocarbon trap set at -20 C followed by trap heating and analysis by GC/Ms. In addition, the samples were also extracted using a low temperature "one-pot" chemical extraction technique using N-methyl, N-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA) as the silylating agent prior to GC/MS analysis. We identified several aldehydes, thiols, and alkene nitriles after pyrolysis GC/MS analysis of the bacteria that were not found in the olivine control samples that had not been inoculated with bacteria. The distribution of pyrolysis products extracted from the

  5. Trace uranium analysis in Indian coal samples using the fission track technique

    International Nuclear Information System (INIS)

    Jojo, P.J.; Rawat, A.; Kumar, Ashavani; Prasad, Rajendra

    1993-01-01

    The ever-growing demand for energy has resulted in the extensive use of fossil fuels, especially coal, for power generation. Coal and its by-products often contain significant amounts of radionuclides, including uranium, which is the ultimate source of the radioactive gas Radon-222. The present study gives the concentration of uranium in coal samples of different collieries in India, collected from various thermal power plants in the state of Uttar Pradesh. The estimates were made using the fission track technique. Latent damage tracks were not found to be uniformly distributed but showed sun bursts and clusters. Non-uniform distributions of trace elements are a very common phenomenon in rocks. The levels of uranium in the coal samples were found to vary from 2.0 to 4.9 ppm in uniform distributions and from 21.3 to 41.0 ppm in non-uniform distributions. Measurements were also made on fly ash samples where the average uranium concentration was found to be 8.4 and 49.3 ppm in uniform and non-uniform distributions, respectively. (author)

  6. Performance evaluation of an importance sampling technique in a Jackson network

    Science.gov (United States)

    brahim Mahdipour, E.; Masoud Rahmani, Amir; Setayeshi, Saeed

    2014-03-01

    Importance sampling is a technique that is commonly used to speed up Monte Carlo simulation of rare events. However, little is known regarding the design of efficient importance sampling algorithms in the context of queueing networks. The standard approach, which simulates the system using an a priori fixed change of measure suggested by large deviation analysis, has been shown to fail in even the simplest network settings. Estimating probabilities associated with rare events has been a topic of great importance in queueing theory, and in applied probability at large. In this article, we analyse the performance of an importance sampling estimator for a rare event probability in a Jackson network. This article carries out strict deadlines to a two-node Jackson network with feedback whose arrival and service rates are modulated by an exogenous finite state Markov process. We have estimated the probability of network blocking for various sets of parameters, and also the probability of missing the deadline of customers for different loads and deadlines. We have finally shown that the probability of total population overflow may be affected by various deadline values, service rates and arrival rates.

  7. Determination of organically bound Tritium in environmental samples by application of the oxidizing plasma technique

    International Nuclear Information System (INIS)

    Strack, S.; Koenig, L.A.

    1981-12-01

    The low-temperature oxidizing plasma technique with a suitable system for trapping the water formed in the oxidation process can be used to determine T bound organically in low-level samples. First, the samples are freeze-dried and the tissue water obtained in this way is measured, after distillation, in a liquid scintillation spectrometer. The residual dry matter is ashed in the reactor chamber of the plasma system. Oxidation takes place at temperatures not exceeding 200 0 C in an oxygen flow of about 40 ml/min. The water of oxidation is collected in a cold trap installed behind the reactor chamber. A volume of about 10 ml of water is sufficient to measure the tritium activity without enrichment. The oxidation behavior of various organic materials has been tested. Some first results of T concentrations in tissue water and the organic dry matter from food and plant samples collected in the vicinity of the Nuclear Research Center are presented. The method has the advantage that a commercially available instrument can be used requiring only little additional equipment. Handling is much less dangerous and contamination effects by atmospheric T can be easily kept at a minimum. (orig./HP) [de

  8. Techniques for sampling nuclear waste tank contents and in situ measurement of activity

    International Nuclear Information System (INIS)

    Lawrence, R.C.

    1978-04-01

    A study was conducted to develop suitable sampling equipment and techniques for characterizing the mechanical properties of nuclear wastes; identifying effective means of measuring radiation levels, temperatures, and neutron fluxes in situ in wastes; and developing a waste core sampler. A portable, stainless steel probe was developed which is placed in the tank through a riser. This probe is built for the insertion of instrumentation that can measure the contents of the tank at any level and take temperature, radiation, and neutron activation readings with reliable accuracy. A simple and reliable instrument for the in situ extraction of waste materials ranging from liquid to concrete-like substances was also developed. This portable, stainless steel waste core sampler can remove up to one liter of radioactive waste from tanks for transportation to hot cell laboratories for analysis of hardness, chemical form, and isotopic content. A cask for transporting the waste samples from the tanks to the laboratory under radiation-protected conditions was also fabricated. This cask was designed with a ''boot'' or inner-seal liner to contain any radioactive wastes that might remain on the outside of the waste core sampling device

  9. Comparative study of modern extraction techniques for the determination of environmental samples (M14)

    International Nuclear Information System (INIS)

    Gfrerer, M.; Lankmayr, E.

    2002-01-01

    Full text: The aim of any extraction method in analytical chemistry is, to effectively separate the analytes from the matrix. The whole step should be fast and quantitative with minimal solvent and time required. The classical Soxhlet extraction usually requires large volumes (up to 200 ml) of solvent to be refluxed through the solid samples for several hours. Therefore, in the last decades, alternatives for this extraction method have been presented and investigated such as ultrasonic extraction (UE), supercritical fluid extraction (SFE), accelerated solvent extraction (ASE), microwave-assisted extraction (MAE) and fluidized-bed extraction (FBE). The actual choice for analytical application is frequently the initial capital cost, operating costs, simplicity of operation, amount of organic solvent required and sample throughput. Since sample preparation is a critical step in the analytical cycle, special care has to be taken for an accurate choice and optimization of extraction techniques and clean-up procedures. Therefore, MAE and FBE were investigated for their influential extraction parameters and these parameters were optimized for the extraction of organochlorine biocides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons from environmental matrices like soil, sediment and sewage sludge. The extraction yields were compared with those obtained by Soxhlet extraction performed following DIN-methods. Finally, the optimized modern methods were validated by systematic experiments with certified reference materials. Refs. 3 (author)

  10. Comparison of radiation doses using weight-based protocol and dose modulation techniques for patients undergoing biphasic abdominal computed tomography examinations

    Directory of Open Access Journals (Sweden)

    Livingstone Roshan

    2009-01-01

    Full Text Available Computed tomography (CT of the abdomen contributes a substantial amount of man-made radiation dose to patients and use of this modality is on the increase. This study intends to compare radiation dose and image quality using dose modulation techniques and weight- based protocol exposure parameters for biphasic abdominal CT. Using a six-slice CT scanner, a prospective study of 426 patients who underwent abdominal CT examinations was performed. Constant tube potentials of 90 kV and 120 kV were used for all arterial and portal venous phase respectively. The tube current-time product for weight-based protocol was optimized according to patient′s body weight; this was automatically selected in dose modulations. The effective dose using weight-based protocol, angular and z-axis dose modulation was 11.3 mSv, 9.5 mSv and 8.2 mSv respectively for the patient′s body weight ranging from 40 to 60 kg. For patients of body weights ranging 60 to 80 kg, the effective doses were 13.2 mSv, 11.2 mSv and 10.6 mSv respectively. The use of dose modulation technique resulted in a reduction of 16 to 28% in radiation dose with acceptable diagnostic accuracy in comparison to the use of weight-based protocol settings.

  11. ANALYSIS OF MONTE CARLO SIMULATION SAMPLING TECHNIQUES ON SMALL SIGNAL STABILITY OF WIND GENERATOR- CONNECTED POWER SYSTEM

    Directory of Open Access Journals (Sweden)

    TEMITOPE RAPHAEL AYODELE

    2016-04-01

    Full Text Available Monte Carlo simulation using Simple Random Sampling (SRS technique is popularly known for its ability to handle complex uncertainty problems. However, to produce a reasonable result, it requires huge sample size. This makes it to be computationally expensive, time consuming and unfit for online power system applications. In this article, the performance of Latin Hypercube Sampling (LHS technique is explored and compared with SRS in term of accuracy, robustness and speed for small signal stability application in a wind generator-connected power system. The analysis is performed using probabilistic techniques via eigenvalue analysis on two standard networks (Single Machine Infinite Bus and IEEE 16–machine 68 bus test system. The accuracy of the two sampling techniques is determined by comparing their different sample sizes with the IDEAL (conventional. The robustness is determined based on a significant variance reduction when the experiment is repeated 100 times with different sample sizes using the two sampling techniques in turn. Some of the results show that sample sizes generated from LHS for small signal stability application produces the same result as that of the IDEAL values starting from 100 sample size. This shows that about 100 sample size of random variable generated using LHS method is good enough to produce reasonable results for practical purpose in small signal stability application. It is also revealed that LHS has the least variance when the experiment is repeated 100 times compared to SRS techniques. This signifies the robustness of LHS over that of SRS techniques. 100 sample size of LHS produces the same result as that of the conventional method consisting of 50000 sample size. The reduced sample size required by LHS gives it computational speed advantage (about six times over the conventional method.

  12. Whole arm manipulation planning based on feedback velocity fields and sampling-based techniques.

    Science.gov (United States)

    Talaei, B; Abdollahi, F; Talebi, H A; Omidi Karkani, E

    2013-09-01

    Changing the configuration of a cooperative whole arm manipulator is not easy while enclosing an object. This difficulty is mainly because of risk of jamming caused by kinematic constraints. To reduce this risk, this paper proposes a feedback manipulation planning algorithm that takes grasp kinematics into account. The idea is based on a vector field that imposes perturbation in object motion inducing directions when the movement is considerably along manipulator redundant directions. Obstacle avoidance problem is then considered by combining the algorithm with sampling-based techniques. As experimental results confirm, the proposed algorithm is effective in avoiding jamming as well as obstacles for a 6-DOF dual arm whole arm manipulator. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  13. Yield strength, shear stress and toughness of YBCO samples textured by Bridgman technique

    International Nuclear Information System (INIS)

    Roa, J J; Capdevila, X G; Martinez, M; Segarra, M; Jimenez-Pique, E

    2008-01-01

    Mechanical properties of the orthorhombic phase of YBa 2 Cu 3 O 7-δ (Y-123) at room temperature have been investigated at different applied loads using nanoindentation technique. The study was carried out for several monodomains on the (001) planes for textured Bridgman samples with dispersed Y 2 BaCuO 5 (Y-211) particles as pinning centers. The yield strength (σ ys ), shear stress (τ m ) and toughness (K IC ) of Y123/Y211composite was determined at different applied loads. First and second mechanical properties have been calculated though the Hertz equations and the last one with Lawn et al. equations. Finally, the ultra-low imprints obtained by nanoindentation have been correlated with parameters obtained by Field Emission Scanning Electron Microscope (FE-SEM)

  14. Importance sampling techniques and treatment of electron transport in MCNP 4A

    International Nuclear Information System (INIS)

    Ueki, K.

    1994-01-01

    The continuous energy Monte Carlo code MCNP was developed by the Radiation Transport Group at Los Alamos National Laboratory and the MCNP 4A version is available, now. The MCNP 4A is able to do the coupled neutron-secondary gamma-ray-electron-bremsstrahlung calculation. The calculated results, such as energy spectra, tally fluctuation chart, and geometrical input data can be displayed by using a work station. The document of the MCNP 4A code has no description on the subroutines, except few ones of 'SOURCE', 'TALLYX'. However, when we want to improve the MCNP Monte Carlo sampling techniques to get more accuracy or efficiency results for some problems, some subroutines are required or needed to revised. Three subroutines have been revised and built in the MCNP 4A code. (author)

  15. Simulative Investigation on Spectral Efficiency of Unipolar Codes based OCDMA System using Importance Sampling Technique

    Science.gov (United States)

    Farhat, A.; Menif, M.; Rezig, H.

    2013-09-01

    This paper analyses the spectral efficiency of Optical Code Division Multiple Access (OCDMA) system using Importance Sampling (IS) technique. We consider three configurations of OCDMA system namely Direct Sequence (DS), Spectral Amplitude Coding (SAC) and Fast Frequency Hopping (FFH) that exploits the Fiber Bragg Gratings (FBG) based encoder/decoder. We evaluate the spectral efficiency of the considered system by taking into consideration the effect of different families of unipolar codes for both coherent and incoherent sources. The results show that the spectral efficiency of OCDMA system with coherent source is higher than the incoherent case. We demonstrate also that DS-OCDMA outperforms both others in terms of spectral efficiency in all conditions.

  16. Calibrated Phase-Shifting Digital Holographic Microscope Using a Sampling Moiré Technique

    Directory of Open Access Journals (Sweden)

    Peng Xia

    2018-05-01

    Full Text Available A calibrated phase-shifting digital holographic microscope system capable of improving the quality of reconstructed images is proposed. Phase-shifting errors are introduced in phase-shifted holograms for numerous reasons, such as the non-linearity of piezoelectric transducers (PZTs, wavelength fluctuations in lasers, and environmental disturbances, leading to poor-quality reconstructions. In our system, in addition to the camera used to record object information, an extra camera is used to record interferograms, which are used to analyze phase-shifting errors using a sampling Moiré technique. The quality of the reconstructed object images can be improved by the phase-shifting error compensation algorithm. Both the numerical simulation and experiment demonstrate the effectiveness of the proposed system.

  17. Probabilistic techniques using Monte Carlo sampling for multi- component system diagnostics

    International Nuclear Information System (INIS)

    Aumeier, S.E.; Lee, J.C.; Akcasu, A.Z.

    1995-01-01

    We outline the structure of a new approach at multi-component system fault diagnostics which utilizes detailed system simulation models, uncertain system observation data, statistical knowledge of system parameters, expert opinion, and component reliability data in an effort to identify incipient component performance degradations of arbitrary number and magnitude. The technique involves the use of multiple adaptive Kalman filters for fault estimation, the results of which are screened using standard hypothesis testing procedures to define a set of component events that could have transpired. Latin Hypercube sample each of these feasible component events in terms of uncertain component reliability data and filter estimates. The capabilities of the procedure are demonstrated through the analysis of a simulated small magnitude binary component fault in a boiling water reactor balance of plant. The results show that the procedure has the potential to be a very effective tool for incipient component fault diagnosis

  18. DNA isolation protocols affect the detection limit of PCR approaches of bacteria in samples from the human gastrointestinal tract

    NARCIS (Netherlands)

    Zoetendal, E.G.; Ben-Amor, K.; Akkermans, A.D.L.; Abee, T.; Vos, de W.M.

    2001-01-01

    A major concern in molecular ecological studies is the lysis efficiency of different bacteria in a complex ecosystem. We used a PCR-based 16S rDNA approach to determine the effect of two DNA isolation protocols (i.e. the bead beating and Triton-X100 method) on the detection limit of seven

  19. Surface Sampling-Based Decontamination Studies and Protocol for Determining Sporicidal Efficacy of Gaseous Fumigants on Military-Relevant Surfaces

    Science.gov (United States)

    2008-09-01

    non-porous surfaces is vital to decon protocol development. Spore density (spore number per unit area) can result in layering and clustering over a...1999, 281, 1735-1745. 9. AOAC International Method 966.04; Official Methods of Analisis , 21’t ed.; Chapter 6: AOAC International: Gaithersburg, MD

  20. Comparison of mobile and stationary spore-sampling techniques for estimating virulence frequencies in aerial barley powdery mildew populations

    DEFF Research Database (Denmark)

    Hovmøller, M.S.; Munk, L.; Østergård, Hanne

    1995-01-01

    Gene frequencies in samples of aerial populations of barley powdery mildew (Erysiphe graminis f.sp. hordei), which were collected in adjacent barley areas and in successive periods of time, were compared using mobile and stationary sampling techniques. Stationary samples were collected from trap ...

  1. Tracer techniques for urine volume determination and urine collection and sampling back-up system

    Science.gov (United States)

    Ramirez, R. V.

    1971-01-01

    The feasibility, functionality, and overall accuracy of the use of lithium were investigated as a chemical tracer in urine for providing a means of indirect determination of total urine volume by the atomic absorption spectrophotometry method. Experiments were conducted to investigate the parameters of instrumentation, tracer concentration, mixing times, and methods for incorporating the tracer material in the urine collection bag, and to refine and optimize the urine tracer technique to comply with the Skylab scheme and operational parameters of + or - 2% of volume error and + or - 1% accuracy of amount of tracer added to each container. In addition, a back-up method for urine collection and sampling system was developed and evaluated. This back-up method incorporates the tracer technique for volume determination in event of failure of the primary urine collection and preservation system. One chemical preservative was selected and evaluated as a contingency chemical preservative for the storage of urine in event of failure of the urine cooling system.

  2. Synchrotron X-ray measurement techniques for thermal barrier coated cylindrical samples under thermal gradients

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, Sanna F.; Knipe, Kevin; Manero, Albert; Raghavan, Seetha [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida 32816 (United States); Meid, Carla; Wischek, Janine; Bartsch, Marion [German Aerospace Center (DLR), Institute of Materials Research, 51147 Cologne (Germany); Okasinski, John; Almer, Jonathan [X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Karlsson, Anette M. [Cleveland State University, 2121 Euclid Avenue, Cleveland, Ohio 44115 (United States)

    2013-08-15

    Measurement techniques to obtain accurate in situ synchrotron strain measurements of thermal barrier coating systems (TBCs) applied to hollow cylindrical specimens are presented in this work. The Electron Beam Physical Vapor Deposition coated specimens with internal cooling were designed to achieve realistic temperature gradients over the TBC coated material such as that occurring in the turbine blades of aeroengines. Effects of the circular cross section on the x-ray diffraction (XRD) measurements in the various layers, including the thermally grown oxide, are investigated using high-energy synchrotron x-rays. Multiple approaches for beam penetration including collection, tangential, and normal to the layers, along with variations in collection parameters are compared for their ability to attain high-resolution XRD data from the internal layers. This study displays the ability to monitor in situ, the response of the internal layers within the TBC, while implementing a thermal gradient across the thickness of the coated sample. The thermal setup maintained coating surface temperatures in the range of operating conditions, while monitoring the substrate cooling, for a controlled thermal gradient. Through variation in measurement location and beam parameters, sufficient intensities are obtained from the internal layers which can be used for depth resolved strain measurements. Results are used to establish the various techniques for obtaining XRD measurements through multi-layered coating systems and their outcomes will pave the way towards goals in achieving realistic in situ testing of these coatings.

  3. The development and use of parametric sampling techniques for probabilistic risk assessment

    International Nuclear Information System (INIS)

    Dalrymple, G.J.; Broyd, T.W.

    1987-01-01

    In order to enable evaluation to be made of proposals for the underground disposal of low and intermediate level radioactive wastes in the United Kingdom, the Department of the Environment (DoE) research programme includes development of computer-based methods for use in a multistage assessment process. To test the adequacy of the various methods of data acquisitions and radiological assessment a mock assessment exercise is currently being conducted by the department. This paper outlines the proposed methodology which provides for the use of probabilistic modelling based upon the Atomic Energy of Canada Ltd SYVAC variability analysis approach using new models (SYVAC 'A') and data appropriate to UK conditions for a deep horizontal tunnel repository concept. This chapter describes the choice of a suitable technique for the sampling of data input to the SYVAC 'A' model and techniques for analysing the predictions of dose and risk made by the model. The sensitivity of the model predictions (risk and dose to man) to the input parameters was compared for four different methods. All four methods identified the same geological parameters as the most important. (author)

  4. Improved technique for measuring the size distribution of black carbon particles in rainwater and snow samples

    Science.gov (United States)

    Mori, T.; Moteki, N.; Ohata, S.; Koike, M.; Azuma, K. G.; Miyazaki, Y.; Kondo, Y.

    2015-12-01

    Black carbon (BC) is the strongest contributor to sunlight absorption among atmospheric aerosols. Quantitative understanding of wet deposition of BC, which strongly affects the spatial distribution of BC, is important to improve our understandings on climate change. We have devised a technique for measuring the masses of individual BC particles in rainwater and snow samples, as a combination of a nebulizer and a single-particle soot photometer (SP2) (Ohata et al. 2011, 2013; Schwarz et al. 2012; Mori et al. 2014). We show two important improvements in this technique: 1)We have extended the upper limit of detectable BC particle diameter from 0.9 μm to about 4.0 μm by modifying the photodetector for measuring the laser-induced incandescence signal. 2)We introduced a pneumatic nebulizer Marin-5 (Cetac Technologies Inc., Omaha, NE, USA) and experimentally confirmed its high extraction efficiency (~50%) independent of particle diameter up to 2.0 μm. Using our improved system, we simultaneously measured the size distribution of BC particles in air and rainwater in Tokyo. We observed that the size distribution of BC in rainwater was larger than that in air, indicating that large BC particles were effectively removed by precipitation. We also observed BC particles with diameters larger than 1.0 μm, indicating that further studies of wet deposition of BC will require the use of the modified SP2.

  5. Solving mercury (Hg) speciation in soil samples by synchrotron X-ray microspectroscopic techniques

    International Nuclear Information System (INIS)

    Terzano, Roberto; Santoro, Anna; Spagnuolo, Matteo; Vekemans, Bart; Medici, Luca; Janssens, Koen; Goettlicher, Joerg; Denecke, Melissa A.; Mangold, Stefan; Ruggiero, Pacifico

    2010-01-01

    Direct mercury (Hg) speciation was assessed for soil samples with a Hg concentration ranging from 7 up to 240 mg kg -1 . Hg chemical forms were identified and quantified by sequential extractions and bulk- and micro-analytical techniques exploiting synchrotron generated X-rays. In particular, microspectroscopic techniques such as μ-XRF, μ-XRD and μ-XANES were necessary to solve bulk Hg speciation, in both soil fractions 3 S 2 Cl 2 ), and an amorphous phase containing Hg bound to chlorine and sulfur. The amount of metacinnabar and amorphous phases increased in the fraction <2 μm. No interaction among Hg-species and soil components was observed. All the observed Hg-species originated from the slow weathering of an inert Hg-containing waste material (K106, U.S. EPA) dumped in the area several years ago, which is changing into a relatively more dangerous source of pollution. - Direct mercury (Hg) speciation in chlor-alkali plant contaminated soils enabled the identification of potentially dangerous Hg-S/Cl amorphous species.

  6. Effect of postmortem sampling technique on the clinical significance of autopsy blood cultures.

    Science.gov (United States)

    Hove, M; Pencil, S D

    1998-02-01

    Our objective was to investigate the value of postmortem autopsy blood cultures performed with an iodine-subclavian technique relative to the classical method of atrial heat searing and antemortem blood cultures. The study consisted of a prospective autopsy series with each case serving as its own control relative to subsequent testing, and a retrospective survey of patients coming to autopsy who had both autopsy blood cultures and premortem blood cultures. A busy academic autopsy service (600 cases per year) at University of Texas Medical Branch Hospitals, Galveston, Texas, served as the setting for this work. The incidence of non-clinically relevant (false-positive) culture results were compared using different methods for collecting blood samples in a prospective series of 38 adult autopsy specimens. One hundred eleven adult autopsy specimens in which both postmortem and antemortem blood cultures were obtained were studied retrospectively. For both studies, positive culture results were scored as either clinically relevant or false positives based on analysis of the autopsy findings and the clinical summary. The rate of false-positive culture results obtained by an iodine-subclavian technique from blood drawn soon after death were statistically significantly lower (13%) than using the classical method of obtaining blood through the atrium after heat searing at the time of the autopsy (34%) in the same set of autopsy subjects. When autopsy results were compared with subjects' antemortem blood culture results, there was no significant difference in the rate of non-clinically relevant culture results in a paired retrospective series of antemortem blood cultures and postmortem blood cultures using the iodine-subclavian postmortem method (11.7% v 13.5%). The results indicate that autopsy blood cultures obtained using the iodine-subclavian technique have reliability equivalent to that of antemortem blood cultures.

  7. [Sampling, storage and transport of biological materials collected from living and deceased subjects for determination of concentration levels of ethyl alcohol and similarly acting substances. A proposal of updating the blood and urine sampling protocol].

    Science.gov (United States)

    Wiergowski, Marek; Reguła, Krystyna; Pieśniak, Dorota; Galer-Tatarowicz, Katarzyna; Szpiech, Beata; Jankowski, Zbigniew

    2007-01-01

    The present paper emphasizes the most common mistakes committed at the beginning of an analytical procedure. To shorten the time and decrease the cost of determinations of substances with similar to alcohol activity, it is postulated to introduce mass-scale screening analysis of saliva collected from a living subject at the site of the event, with all positive results confirmed in blood or urine samples. If no saliva sample is collected for toxicology, a urine sample, allowing for a stat fast screening analysis, and a blood sample, to confirm the result, should be ensured. Inappropriate storage of a blood sample in the tube without a preservative can cause sample spilling and its irretrievable loss. The authors propose updating the "Blood/urine sampling protocol", with the updated version to be introduced into practice following consultations and revisions.

  8. General principles governing sampling and measurement techniques for monitoring radioactive effluents from nuclear facilities

    International Nuclear Information System (INIS)

    Fitoussi, L.

    1978-01-01

    An explanation is given of the need to monitor the release of radioactive gases and liquid effluents from nuclear facilities, with particular emphasis on the ICRP recommendations and on the interest in this problem shown by the larger international organizations. This is followed by a description of the classes of radionuclides that are normally monitored in this way. The characteristics of monitoring 'in line' and 'by sample taking' are described; the disadvantages of in line monitoring and the problem of sample representativity are discussed. There follows an account of the general principles for measuring gaseous and liquid effluents that are applied in the techniques normally employed at nuclear facilities. Standards relating to the specifications for monitoring instruments are at present being devised by the International Electrotechnical Commission, and there are still major differences in national practices, at least as far as measurement thresholds are concerned. In conclusion, it is shown that harmonization of practices and standardization of equipment would probably help to make international relations in the field more productive. (author)

  9. Determination of elemental in soil samples from Gebeng area using NAA technique

    International Nuclear Information System (INIS)

    Md Suhaimi Elias; Wo, Y.M.; Mohd Suhaimi Hamzah

    2016-01-01

    Rapid development and urbanization will increase number of residence and industrial area. Without proper management and control of pollution, these will give an adverse effect to environment and human life. The objective of this study to identify and quantify key contaminants into the environment of the Gebeng area as a result of industrial and human activities. Gebeng area was gazetted as one of the industrial estate in Pahang state. Assessment of elemental pollution in soil of Gebeng area base on level of concentration, enrichment factor and geo-accumulation index. The enrichment factors (EFs) were determined by the elemental rationing method, whilst the geo-accumulation index (I_g_e_o) by comparing of current to continental crustal average concentration of element. Twenty-seven of soil samples were collected from Gebeng area. Soil samples were analysed by using Neutron Activation Analyses (NAA) technique. The obtained data showed higher concentration of iron (Fe) due to abundance in soil compared to other elements. The results of enrichment factor showed that Gebeng area have enrich with elements of As, Br, Hf, Sb, Th and U. Base on the geo-accumulation index (I_g_e_o) classification, the soil quality of Gebeng area can be classified as class 0, (uncontaminated) to Class 3, (moderately to heavily contaminated). (author)

  10. Determination of the uranium concentration in water samples by the technique of fission track recording

    International Nuclear Information System (INIS)

    Geraldo, L.P.

    1979-01-01

    The technique of fission track register was developed for the determination of micrograms of uranium. The Makrofol KG, a synthetic plastic made by Bayer, was used as the detector and the wet method was utilized. The detector calibration curve allows the determination of the uranium concentration in a sample within an interval from 8.0 to 0.4μgU/L, the total error ranging from 3.3% to 29.0% respectively. The method was used in the determination of the uranium content in various water samples, obtained from various sources like rivers, sea etc. in the state of Sao Paulo, Brazil. Results were compared with those obtained by other authors using different methods. The average concentration found in sea waters (3.27 +- 9.12μgU/l) by this method is compatible with the international average accepted value of 3.3μgU/l, irrespective of site and depth. The determination of the uranium content by fission track counting has proved to be very convenient. (Author) [pt

  11. Integration of GC-MSD and ER-Calux® assay into a single protocol for determining steroid estrogens in environmental samples.

    Science.gov (United States)

    Avberšek, Miha; Žegura, Bojana; Filipič, Metka; Heath, Ester

    2011-11-01

    There are many published studies that use either chemical or biological methods to investigate steroid estrogens in the aquatic environment, but rarer are those that combine both. In this study, gas chromatography with mass selective detection (GC-MSD) and the ER-Calux(®) estrogenicity assay were integrated into a single protocol for simultaneous determination of natural (estrone--E1, 17β-estradiol--E2, estriol--E3) and synthetic (17α-ethinylestradiol--EE2) steroid estrogens concentrations and the total estrogenic potential of environmental samples. For integration purposes, several solvents were investigated and the commonly used dimethyl sulphoxide (DMSO) in the ER-Calux(®) assay was replaced by ethyl acetate, which is more compatible with gas chromatography and enables the same sample to be analysed by both GC-MSD and the ER-Calux(®) assay. The integrated protocol was initially tested using a standard mixture of estrogens. The results for pure standards showed that the estrogenicity calculated on the basis of GC-MSD and the ER-Calux(®) assay exhibited good correlation (r(2)=0.96; α=0.94). The result remained the same when spiked waste water extracts were tested (r(2)=0.92, α=1.02). When applied to real waste water influent and effluent samples the results proved (r(2)=0.93; α=0.99) the applicability of the protocol. The main advantages of this newly developed protocol are simple sample handling for both methods, and reduced material consumption and labour. In addition, it can be applied as either a complete or sequential analysis where the ER-Calux(®) assay is used as a pre-screening method prior to the chemical analysis. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Staged protocol for the treatment of chronic femoral shaft osteomyelitis with Ilizarov's technique followed by the use of intramedullary locked nail.

    Science.gov (United States)

    Chou, Po-Hsin; Lin, Hsi-Hsien; Su, Yu-Pin; Chiang, Chao-Ching; Chang, Ming-Chau; Chen, Chuan-Mu

    2017-06-01

    Infected nonunion of the femoral shaft is uncommon, and usually presents with challenging therapeutic and reconstructive problems. There are still controversies over treating infected nonunion of the femoral shaft. The purposes of this retrospective study were to review the treatment outcomes and describe a staged protocol for spontaneous wound healing. Six patients with chronic femoral shaft infected-nonunion from October 2002 to September 2010 were included in this retrospective study. Serial plain films and triple films of lower legs were performed to evaluate the alignment of the treated femoral shaft and bony union following our staged protocol of Ilizarov distraction osteogenesis and intramedullary nailing. An average bone defect of 7 cm was noted after staged osteotomy. Mean follow-up was 87.5 (range, 38-133) months. Union was achieved in all six patients, with an average external fixation time of 6.8 (range, 5-11) months. There was no reinfection. One complication of a 4-cm leg discrepancy was noted, with an initial shortening of 15 cm. The mean knee ranges of motion (ROM) before staged protocols and at final follow-up were 64.2±8.6 (range, 60-75)° and 53.3±9.3 (range, 40-65)°, respectively. The ROM at the knee joint statistically decreased following staged protocols. In the treatment of chronic femur osteomyelitis, the staged protocol of Ilizarov distraction osteogenesis followed by intramedullary nailing was safe and successful, and allowed for union, realignment, reorientation, and leg-length restoration. With regard to the soft tissue, this technique provides a unique type of reconstructive closure for infected wounds. It is suggested that the staged protocol is reliable in providing successful simultaneous reconstruction for bone and soft tissue defects without flap coverage. Copyright © 2017. Published by Elsevier Taiwan LLC.

  13. Evaluation of a lateral flow-based technology card for blood typing using a simplified protocol in a model of extreme blood sampling conditions.

    Science.gov (United States)

    Clavier, Benoît; Pouget, Thomas; Sailliol, Anne

    2018-02-01

    Life-threatening situations requiring blood transfusion under extreme conditions or in remote and austere locations, such as the battlefield or in traffic accidents, would benefit from reliable blood typing practices that are easily understood by a nonscientist or nonlaboratory technician and provide quick results. A simplified protocol was developed for the lateral flow-based device MDmulticard ABO-D-Rh subgroups-K. Its performance was compared to a reference method (PK7300, Beckman Coulter) in native blood samples from donors. The method was tested on blood samples stressed in vitro as a model of hemorrhage cases (through hemodilution using physiologic serum) and dehydration (through hemoconcentration by removing an aliquot of plasma after centrifugation), respectively. A total of 146 tests were performed on 52 samples; 126 in the hemodilution group (42 for each native, diluted 1/2, and diluted 1/4 samples) and 20 in the hemoconcentration group (10 for each native and 10% concentrated samples). Hematocrit in the tested samples ranged from 9.8% to 57.6% while hemoglobin levels ranged from 3.2 to 20.1 g/dL. The phenotype profile detected with the MDmulticard using the simplified protocol resulted in 22 A, seven B, 20 O, and three AB, of which nine were D- and five were Kell positive. No discrepancies were found with respect to the results obtained with the reference method. The simplified protocol for MDmulticard use could be considered a reliable method for blood typing in extreme environment or emergency situations, worsened by red blood cell dilution or concentration. © 2017 AABB.

  14. Immunochemical protocols

    National Research Council Canada - National Science Library

    Pound, John D

    1998-01-01

    ... easy and important refinements often are not published. This much anticipated 2nd edition of Immunochemzcal Protocols therefore aims to provide a user-friendly up-to-date handbook of reliable techniques selected to suit the needs of molecular biologists. It covers the full breadth of the relevant established immunochemical methods, from protein blotting and immunoa...

  15. The particle analysis based on FT-TIMS technique for swipe sample under the frame of nuclear safeguard

    International Nuclear Information System (INIS)

    Yang Tianli; Liu Xuemei; Liu Zhao; Tang Lei; Long Kaiming

    2008-06-01

    Under the frame of nuclear safeguard, the particles analysis for swipe sample is an advance mean to detect the undeclared uranium enriched facilities and undeclared uranium enriched activity. The technique of particle analysis based on fission track-thermal ionization mass spectrometry (FT-TIMS) for swipe sample have been built. The reliability and the experimental background for selecting particles consisting of uranium from swipe sample by FT method have been verified. In addition, the utilization coefficient of particles on the surface of swipe sample have also been tested. These works have provided the technique support for application in the area of nuclear verification. (authors)

  16. Quantifying ruminal nitrogen metabolism using the omasal sampling technique in cattle--a meta-analysis.

    Science.gov (United States)

    Broderick, G A; Huhtanen, P; Ahvenjärvi, S; Reynal, S M; Shingfield, K J

    2010-07-01

    Mixed model analysis of data from 32 studies (122 diets) was used to evaluate the precision and accuracy of the omasal sampling technique for quantifying ruminal-N metabolism and to assess the relationships between nonammonia-N flow at the omasal canal and milk protein yield. Data were derived from experiments in cattle fed North American diets (n=36) based on alfalfa silage, corn silage, and corn grain and Northern European diets (n=86) composed of grass silage and barley-based concentrates. In all studies, digesta flow was quantified using a triple-marker approach. Linear regressions were used to predict microbial-N flow to the omasum from intake of dry matter (DM), organic matter (OM), or total digestible nutrients. Efficiency of microbial-N synthesis increased with DM intake and there were trends for increased efficiency with elevated dietary concentrations of crude protein (CP) and rumen-degraded protein (RDP) but these effects were small. Regression of omasal rumen-undegraded protein (RUP) flow on CP intake indicated that an average 32% of dietary CP escaped and 68% was degraded in the rumen. The slope from regression of observed omasal flows of RUP on flows predicted by the National Research Council (2001) model indicated that NRC predicted greater RUP supply. Measured microbial-N flow was, on average, 26% greater than that predicted by the NRC model. Zero ruminal N-balance (omasal CP flow=CP intake) was obtained at dietary CP and RDP concentrations of 147 and 106 g/kg of DM, corresponding to ruminal ammonia-N and milk urea N concentrations of 7.1 and 8.3mg/100mL, respectively. Milk protein yield was positively related to the efficiency of microbial-N synthesis and measured RUP concentration. Improved efficiency of microbial-N synthesis and reduced ruminal CP degradability were positively associated with efficiency of capture of dietary N as milk N. In conclusion, the results of this study indicate that the omasal sampling technique yields valuable estimates

  17. The novel programmable riometer for in-depth ionospheric and magnetospheric observations (PRIAMOS) using direct sampling DSP techniques

    OpenAIRE

    Dekoulis, G.; Honary, F.

    2005-01-01

    This paper describes the feasibility study and simulation results for the unique multi-frequency, multi-bandwidth, Programmable Riometer for in-depth Ionospheric And Magnetospheric ObservationS (PRIAMOS) based on direct sampling digital signal processing (DSP) techniques. This novel architecture is based on sampling the cosmic noise wavefront at the antenna. It eliminates the usage of any intermediate frequency (IF) mixer stages (-6 dB) and the noise balancing technique (-3 dB), providing a m...

  18. Application of BAT assessments for sampling and monitoring techniques in the UK EPR

    International Nuclear Information System (INIS)

    Kerdaniel, Erwan du Fou de; Colin, Julie; Moyano, Florian; Ardon, Audrey

    2014-01-01

    EDF Energy intends to build two EPR units at the Hinkley Point C site and has initiated the studies to build two more EPR units at Sizewell C. The project is lead by NNB GenCo, a subsidiary of EDF Energy. NNB GenCo, identified as the future operator and intelligent customer, relies upon EDF SA's expertise as responsible designer. UK EPR design substantiation has been carried out during the Generic Design Assessment (GDA), with two key reports, namely the Pre-Construction Environmental Report and the Pre-Construction Safety Report. These reports lead to specific enquiries initiated by the Regulators through 'Assessment Findings' in all areas, including Chemistry. Along the GDA process, the Environmental Agency (EA) has authorised chemical and radiochemical effluents discharges, requiring NNB GenCo to demonstrate that Best Available Techniques (BAT) are used to sample and monitor the discharges and the generation of solid wastes. BAT demonstrations deliverables are formalised via 'Commitment Plans' and detailed within 'Environmental Optimisation Studies (EOS)' reports, in line with NNB GenCo's management arrangements. NNB GenCo manages the production of the EOS reports. EDF CEIDRE Laboratory department (CEIDRE/DLAB) has been identified as a contributor to the BAT demonstration regarding sampling and monitoring of chemical effluents, active effluents and solid wastes. As required by the definition of BAT in the UK context, demonstrations are based on: UK Regulatory context and associated specific requirements, International feedback analysis of European, EPRI and IAEA documents, French fleet framework: benchmarks with the operator, analysis of technical and operational management documentation, Sizewell B framework: benchmarks with the operator, analysis of technical and operational management documents, International, British and French standards. A close partnership between the different EDF SA departments and a clear

  19. Analyses of archaeological pottery samples using X-ray fluorescence technique for provenance study

    International Nuclear Information System (INIS)

    Tamilarasu, S.; Swain, K.K.; Singhal, R.K; Reddy, A.V.R.; Acharya, R.; Velraj, G.

    2015-01-01

    Archaeological artifacts reveal information on past human activities, artifact preparation technology, art and possible trade. Ceramics are the most stable and abundant material in archaeological context. Pottery is the most abundant tracers in all archaeological excavations. Compared to major elements, elements present at trace concentrations levels are source specific and they maintain same concentration levels in source clay as well as finished products e.g., fired clay potteries. As it is difficult to find out exact source or origin, provenance study is carried out first to establish whether objects under study are from the same or different sources/origin. Various analytical techniques like instrumental neutron activation analysis (INAA), Ion beam analysis (IBA) and X-ray fluorescence (XRF) have been used for obtaining elemental concentrations in archaeological potteries. Portable X-ray fluorescence (pXRF) spectrometry provides a non-destructive means for elemental characterization of a wide range of archaeological materials. Ten archaeological pottery samples were collected from Kottapuram, Kerala under the supervision of archaeological survey of India. Portable X-ray fluorescence (pXRF) spectrometry using a handheld Olympus Innov-X Delta XRF device, ACD BARC, has been used for chemical characterization of the pottery samples. The instrument is equipped with the Delta Rhodium (Rh) anode X-Ray tube and uses a Silicon Drift Detector (resolution <200 eV at 5.95 keV Mn Kα X-ray). NIST 2781 SRM was analyzed for quality control purpose. Ten elements namely Fe, Ti, Mn, Co, Cu, Zn, Pb, Zr, Mo and Se were chosen for cluster analysis and their concentration values were utilized for multivariate statistical analysis using WinSTAT 9.0

  20. Development of novel separation techniques for biological samples in capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Huan -Tsung [Iowa State Univ., Ames, IA (United States)

    1994-07-27

    This dissertation includes three different topics: general introduction of capillary electrophoresis (CE); gradient in CE and CE in biological separations; and capillary gel electrophoresis (CGE) for DNA separation. Factors such as temperature, viscosity, pH, and the surface of capillary walls affecting the separation performance are demonstrated. A pH gradient between 3.0 and 5.2 is useful to improve the resolution among eight different organic acids. A flow gradient due to the change in the concentration of surfactant, which is able to coat to the capillary wall to change the flow rate and its direction, is also shown as a good way to improve the resolution for organic compounds. A temperature gradient caused by joule heat is shown by voltage programming to enhance the resolution and shorten the separation time for several phenolic compounds. The author also shows that self-regulating dynamic control of electroosmotic flow in CE by simply running separation in different concentrations of surfactant has less matrix effect on the separation performance. One of the most important demonstrations in this dissertation is that the author proposes on-column reaction which gives several advantages including the use of a small amount of sample, low risk of contamination, and time saving and kinetic features. The author uses this idea with laser induced fluorescence (LIF) as a detection mode to detect an on-column digestion of sub-ng of protein. This technique also is applied to single cell analysis in the group.

  1. Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples

    Directory of Open Access Journals (Sweden)

    Christian Alvarez

    2013-02-01

    Full Text Available In this study, we evaluated several techniques for the detection of the yeast form of Cryptococcus in decaying wood and measured the viability of these fungi in environmental samples stored in the laboratory. Samples were collected from a tree known to be positive for Cryptococcus and were each inoculated on 10 Niger seed agar (NSA plates. The conventional technique (CT yielded a greater number of positive samples and indicated a higher fungal density [in colony forming units per gram of wood (CFU.g-1] compared to the humid swab technique (ST. However, the difference in positive and false negative results between the CT-ST was not significant. The threshold of detection for the CT was 0.05.10³ CFU.g-1, while the threshold for the ST was greater than 0.1.10³ CFU-1. No colonies were recovered using the dry swab technique. We also determined the viability of Cryptococcus in wood samples stored for 45 days at 25ºC using the CT and ST and found that samples not only continued to yield a positive response, but also exhibited an increase in CFU.g-1, suggesting that Cryptococcus is able to grow in stored environmental samples. The ST.1, in which samples collected with swabs were immediately plated on NSA medium, was more efficient and less laborious than either the CT or ST and required approximately 10 min to perform; however, additional studies are needed to validate this technique.

  2. Contributions from the data samples in NOC technique on the extracting of the Sq variation

    Science.gov (United States)

    Wu, Yingyan; Xu, Wenyao

    2015-04-01

    The solar quiet daily variation, Sq, a rather regular variation is usually observed at mid-low latitudes on magnetic quiet days or less-disturbed days. It is mainly resulted from the dynamo currents in the ionospheric E region, which are driven by the atmospheric tidal wind and different processes and flow as two current whorls in each of the northern and southern hemispheres[1]. The Sq exhibits a conspicuous day-to-day (DTD) variability in daily range (or strength), shape (or phase) and its current focus. This variability is mainly attributed to changes in the ionospheric conductivity and tidal winds, varying with solar radiation and ionospheric conditions. Furthermore, it presents a seasonal variation and solar cycle variation[2-4]. In generally, Sq is expressed with the average value of the five international magnetic quiet days. Using data from global magnetic stations, equivalent current system of daily variation can be constructed to reveal characteristics of the currents[5]. In addition, using the differences of H component at two stations on north and south side of the Sq currents of focus, Sq is extracted much better[6]. Recently, the method of Natural Orthoganal Components (NOC) is used to decompose the magnetic daily variation and express it as the summation of eigenmodes, and indicate the first NOC eigenmode as the solar quiet daily variation, the second as the disturbance daily variation[7-9]. As we know, the NOC technique can help reveal simpler patterns within a complex set of variables, without designed basic-functions such as FFT technique. But the physical explanation of the NOC eigenmodes is greatly depends on the number of data samples and data regular-quality. Using the NOC method, we focus our present study on the analysis of the hourly means of the H component at BMT observatory in China from 2001 to 2008. The contributions of the number and the regular-quality of the data samples on which eigenmode corresponds to the Sq are analyzed, by

  3. Sample processing, protocol, and statistical analysis of the time-of-flight secondary ion mass spectrometry (ToF-SIMS) of protein, cell, and tissue samples.

    Science.gov (United States)

    Barreto, Goncalo; Soininen, Antti; Sillat, Tarvo; Konttinen, Yrjö T; Kaivosoja, Emilia

    2014-01-01

    Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is increasingly being used in analysis of biological samples. For example, it has been applied to distinguish healthy and osteoarthritic human cartilage. This chapter discusses ToF-SIMS principle and instrumentation including the three modes of analysis in ToF-SIMS. ToF-SIMS sets certain requirements for the samples to be analyzed; for example, the samples have to be vacuum compatible. Accordingly, sample processing steps for different biological samples, i.e., proteins, cells, frozen and paraffin-embedded tissues and extracellular matrix for the ToF-SIMS are presented. Multivariate analysis of the ToF-SIMS data and the necessary data preprocessing steps (peak selection, data normalization, mean-centering, and scaling and transformation) are discussed in this chapter.

  4. Testing Behavior Change Techniques to Encourage Primary Care Physicians to Access Cancer Screening Audit and Feedback Reports: Protocol for a Factorial Randomized Experiment of Email Content.

    Science.gov (United States)

    Vaisson, Gratianne; Witteman, Holly O; Bouck, Zachary; Bravo, Caroline A; Desveaux, Laura; Llovet, Diego; Presseau, Justin; Saragosa, Marianne; Taljaard, Monica; Umar, Shama; Grimshaw, Jeremy M; Tinmouth, Jill; Ivers, Noah M

    2018-02-16

    Cancer Care Ontario's Screening Activity Report (SAR) is an online audit and feedback tool designed to help primary care physicians in Ontario, Canada, identify patients who are overdue for cancer screening or have abnormal results requiring follow-up. Use of the SAR is associated with increased screening rates. To encourage SAR use, Cancer Care Ontario sends monthly emails to registered primary care physicians announcing that updated data are available. However, analytics reveal that 50% of email recipients do not open the email and less than 7% click the embedded link to log in to their report. The goal of the study is to determine whether rewritten emails result in increased log-ins. This manuscript describes how different user- and theory-informed messages intended to improve the impact of the monthly emails will be experimentally tested and how a process evaluation will explore why and how any effects observed were (or were not) achieved. A user-centered approach was used to rewrite the content of the monthly email, including messages operationalizing 3 behavior change techniques: anticipated regret, material incentive (behavior), and problem solving. A pragmatic, 2x2x2 factorial experiment within a multiphase optimization strategy will test the redesigned emails with an embedded qualitative process evaluation to understand how and why the emails may or may not have worked. Trial outcomes will be ascertained using routinely collected administrative data. Physicians will be recruited for semistructured interviews using convenience and snowball sampling. As of April 2017, 5576 primary care physicians across the province of Ontario, Canada, had voluntarily registered for the SAR, and in so doing, signed up to receive the monthly email updates. From May to August 2017 participants received the redesigned monthly emails with content specific to their allocated experimental condition prompting use of the SAR. We have not yet begun analyses. This study will inform

  5. Efficient sampling techniques for uncertainty quantification in history matching using nonlinear error models and ensemble level upscaling techniques

    KAUST Repository

    Efendiev, Y.

    2009-11-01

    The Markov chain Monte Carlo (MCMC) is a rigorous sampling method to quantify uncertainty in subsurface characterization. However, the MCMC usually requires many flow and transport simulations in evaluating the posterior distribution and can be computationally expensive for fine-scale geological models. We propose a methodology that combines coarse- and fine-scale information to improve the efficiency of MCMC methods. The proposed method employs off-line computations for modeling the relation between coarse- and fine-scale error responses. This relation is modeled using nonlinear functions with prescribed error precisions which are used in efficient sampling within the MCMC framework. We propose a two-stage MCMC where inexpensive coarse-scale simulations are performed to determine whether or not to run the fine-scale (resolved) simulations. The latter is determined on the basis of a statistical model developed off line. The proposed method is an extension of the approaches considered earlier where linear relations are used for modeling the response between coarse-scale and fine-scale models. The approach considered here does not rely on the proximity of approximate and resolved models and can employ much coarser and more inexpensive models to guide the fine-scale simulations. Numerical results for three-phase flow and transport demonstrate the advantages, efficiency, and utility of the method for uncertainty assessment in the history matching. Copyright 2009 by the American Geophysical Union.

  6. Techniques and Protocols for Dispersing Nanoparticle Powders in Aqueous Media-Is there a Rationale for Harmonization?

    Science.gov (United States)

    Hartmann, Nanna B; Jensen, Keld Alstrup; Baun, Anders; Rasmussen, Kirsten; Rauscher, Hubert; Tantra, Ratna; Cupi, Denisa; Gilliland, Douglas; Pianella, Francesca; Riego Sintes, Juan M

    2015-01-01

    Selecting appropriate ways of bringing engineered nanoparticles (ENP) into aqueous dispersion is a main obstacle for testing, and thus for understanding and evaluating, their potential adverse effects to the environment and human health. Using different methods to prepare (stock) dispersions of the same ENP may be a source of variation in the toxicity measured. Harmonization and standardization of dispersion methods applied in mammalian and ecotoxicity testing are needed to ensure a comparable data quality and to minimize test artifacts produced by modifications of ENP during the dispersion preparation process. Such harmonization and standardization will also enhance comparability among tests, labs, and studies on different types of ENP. The scope of this review was to critically discuss the essential parameters in dispersion protocols for ENP. The parameters are identified from individual scientific studies and from consensus reached in larger scale research projects and international organizations. A step-wise approach is proposed to develop tailored dispersion protocols for ecotoxicological and mammalian toxicological testing of ENP. The recommendations of this analysis may serve as a guide to researchers, companies, and regulators when selecting, developing, and evaluating the appropriateness of dispersion methods applied in mammalian and ecotoxicity testing. However, additional experimentation is needed to further document the protocol parameters and investigate to what extent different stock dispersion methods affect ecotoxicological and mammalian toxicological responses of ENP.

  7. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  8. Evaluation of alternative macroinvertebrate sampling techniques for use in a new tropical freshwater bioassessment scheme

    OpenAIRE

    Isabel Eleanor Moore; Kevin Joseph Murphy

    2015-01-01

    Aim: The study aimed to determine the effectiveness of benthic macroinvertebrate dredge net sampling procedures as an alternative method to kick net sampling in tropical freshwater systems, specifically as an evaluation of sampling methods used in the Zambian Invertebrate Scoring System (ZISS) river bioassessment scheme. Tropical freshwater ecosystems are sometimes dangerous or inaccessible to sampling teams using traditional kick-sampling methods, so identifying an alternative procedure that...

  9. Demonstration of the Attributes of Multi-increment Sampling and Proper Sample Processing Protocols for the Characterization of Metals on DoD Facilities

    Science.gov (United States)

    2013-06-01

    unconsolidated and interbedded sands and clays with minor amounts of gravel and shell fragments. Locally, the site geology consists of impermeable clays , silts...sand, which are well sorted and can contain up to 30% clay . These swale and slough deposits are locally perennially frozen with moderate to high ice...activities include travel, related lodging and meals , labor, and the shipment of samples off site. Unique to the costs associated with sampling activities

  10. Gamma self-shielding correction factors calculation for aqueous bulk sample analysis by PGNAA technique

    International Nuclear Information System (INIS)

    Nasrabadi, M.N.; Mohammadi, A.; Jalali, M.

    2009-01-01

    In this paper bulk sample prompt gamma neutron activation analysis (BSPGNAA) was applied to aqueous sample analysis using a relative method. For elemental analysis of an unknown bulk sample, gamma self-shielding coefficient was required. Gamma self-shielding coefficient of unknown samples was estimated by an experimental method and also by MCNP code calculation. The proposed methodology can be used for the determination of the elemental concentration of unknown aqueous samples by BSPGNAA where knowledge of the gamma self-shielding within the sample volume is required.

  11. A comparative study of sample dissolution techniques and plasma-based instruments for the precise and accurate quantification of REEs in mineral matrices

    Energy Technology Data Exchange (ETDEWEB)

    Whitty-Léveillé, Laurence; Turgeon, Keven [Département de génie des mines, de la métallurgie et des matériaux, Université Laval, Québec, QC (Canada); Département de chimie, Université Laval, Québec, QC (Canada); Bazin, Claude [Département de génie des mines, de la métallurgie et des matériaux, Université Laval, Québec, QC (Canada); Larivière, Dominic, E-mail: dominic.lariviere@chm.ulaval.ca [Département de chimie, Université Laval, Québec, QC (Canada)

    2017-04-08

    The recent commercialisation of inductively coupled plasma tandem mass spectrometric (ICP-MS/MS) instruments has provided analytical chemists with a new tool to properly quantify atomic composition in a variety of matrices with minimal sample preparation. In this article, we report on our assessment of the compatibility of 3 sample preparation techniques (open-vessel acid digestion, microwave digestion and alkaline fusion) for the quantification of rare earth elements (REEs) in mineral matrices. The combination of the high digestion temperatures (1050 °C) and using LiBO{sub 2} as a flux was the most effective strategy for the digestion of all rare earth elements in mineral matrices and was compatible with ICP-MS/MS measurements. We also assessed the analytical performances of ICP-MS/MS against other plasma-based instrumentation (microwave induced plasma and inductively coupled plasma atomic emission spectroscopy (MIP-AES and ICP-AES, respectively) and single quadrupole inductively coupled plasma mass spectrometry (ICP-MS). The comparative study showed that the concentrations obtained by ICP-MS/MS are in excellent agreement with the certified reference material values, and much more suited than the other analytical techniques tested for the quantification of REEs, which exhibited low detectability and/or spectral interferences for some elements/isotopes. Finally, the ruggedness of the analytical protocol proposed which combines a rapid sample dissolution step performed by an automated fusion unit and an ICP-MS/MS as a detector was established using various certified mineral matrices containing variable levels of REEs. - Highlights: • Three types of digestion methods were tested. • Four types of analytical techniques were compared. • Elimination of the spectral interferences encountered in ICP-MS was achieved by the use of Tandem ICP-MS. • Robustness of the analytical procedure was successfully evaluate on four types of certified reference material.

  12. A comparative study of sample dissolution techniques and plasma-based instruments for the precise and accurate quantification of REEs in mineral matrices

    International Nuclear Information System (INIS)

    Whitty-Léveillé, Laurence; Turgeon, Keven; Bazin, Claude; Larivière, Dominic

    2017-01-01

    The recent commercialisation of inductively coupled plasma tandem mass spectrometric (ICP-MS/MS) instruments has provided analytical chemists with a new tool to properly quantify atomic composition in a variety of matrices with minimal sample preparation. In this article, we report on our assessment of the compatibility of 3 sample preparation techniques (open-vessel acid digestion, microwave digestion and alkaline fusion) for the quantification of rare earth elements (REEs) in mineral matrices. The combination of the high digestion temperatures (1050 °C) and using LiBO_2 as a flux was the most effective strategy for the digestion of all rare earth elements in mineral matrices and was compatible with ICP-MS/MS measurements. We also assessed the analytical performances of ICP-MS/MS against other plasma-based instrumentation (microwave induced plasma and inductively coupled plasma atomic emission spectroscopy (MIP-AES and ICP-AES, respectively) and single quadrupole inductively coupled plasma mass spectrometry (ICP-MS). The comparative study showed that the concentrations obtained by ICP-MS/MS are in excellent agreement with the certified reference material values, and much more suited than the other analytical techniques tested for the quantification of REEs, which exhibited low detectability and/or spectral interferences for some elements/isotopes. Finally, the ruggedness of the analytical protocol proposed which combines a rapid sample dissolution step performed by an automated fusion unit and an ICP-MS/MS as a detector was established using various certified mineral matrices containing variable levels of REEs. - Highlights: • Three types of digestion methods were tested. • Four types of analytical techniques were compared. • Elimination of the spectral interferences encountered in ICP-MS was achieved by the use of Tandem ICP-MS. • Robustness of the analytical procedure was successfully evaluate on four types of certified reference material.

  13. Laser-Assisted Sampling Techniques in Combination with ICP-MS: A Novel Approach for Particle Analysis at the IAEA Environmental Samples Laboratory

    International Nuclear Information System (INIS)

    Dzigal, N.; Chinea-Cano, E.

    2015-01-01

    Researchers have found many applications for lasers. About two decades ago, scientists started using lasers as sample introduction instruments for mass spectrometry measurements. Similarly, lasers as micro-dissection tools have also been increasingly on demand in the fields of life sciences, materials science, forensics, etc. This presentation deals with the interception of these aforementioned laser-assisted techniques to the field of particle analysis. Historically, the use of a nanosecond laser to ablate material has been used in materials science. Recently, it has been proven that in the analysis of particulate materials the disadvantages associated with the utilization of nanosecond lasers such as overheating and melting of the sample are suppressed when using femtosecond lasers. Further, due to the length of a single laser shot, fs-LA allows a more controlled ablation to occur and therefore the sample plasma is more homogeneous and less mass-fractionation events are detected. The use of laser micro-dissection devices enables the physical segmentation of microsized artefacts previously performed by a laborious manual procedure. By combining the precision of the laser cutting inherent to the LMD technique together with a particle identification methodology, one can increase the efficiency of single particle isolation. Further, besides the increase in throughput of analyses, this combination enhances the signal-to-noise ratio by removing matrix particles effectively. Specifically, this contribution describes the use of an Olympus+MMI laser microdissection device in improving the sample preparation of environmental swipe samples and the installation of an Applied Spectra J200 fs-LA/LIBS (laser ablation/laser inducedbreakdown spectroscopy) system as a sample introduction device to a quadrupole mass spectrometer, the iCap Q from Thermofisher Scientific at the IAEA Environmental Samples Laboratory are explored. Preliminary results of the ongoing efforts for the

  14. High Throughput Sample Preparation and Analysis for DNA Sequencing, PCR and Combinatorial Screening of Catalysis Based on Capillary Array Technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yonghua [Iowa State Univ., Ames, IA (United States)

    2000-01-01

    Sample preparation has been one of the major bottlenecks for many high throughput analyses. The purpose of this research was to develop new sample preparation and integration approach for DNA sequencing, PCR based DNA analysis and combinatorial screening of homogeneous catalysis based on multiplexed capillary electrophoresis with laser induced fluorescence or imaging UV absorption detection. The author first introduced a method to integrate the front-end tasks to DNA capillary-array sequencers. protocols for directly sequencing the plasmids from a single bacterial colony in fused-silica capillaries were developed. After the colony was picked, lysis was accomplished in situ in the plastic sample tube using either a thermocycler or heating block. Upon heating, the plasmids were released while chromsomal DNA and membrane proteins were denatured and precipitated to the bottom of the tube. After adding enzyme and Sanger reagents, the resulting solution was aspirated into the reaction capillaries by a syringe pump, and cycle sequencing was initiated. No deleterious effect upon the reaction efficiency, the on-line purification system, or the capillary electrophoresis separation was observed, even though the crude lysate was used as the template. Multiplexed on-line DNA sequencing data from 8 parallel channels allowed base calling up to 620 bp with an accuracy of 98%. The entire system can be automatically regenerated for repeated operation. For PCR based DNA analysis, they demonstrated that capillary electrophoresis with UV detection can be used for DNA analysis starting from clinical sample without purification. After PCR reaction using cheek cell, blood or HIV-1 gag DNA, the reaction mixtures was injected into the capillary either on-line or off-line by base stacking. The protocol was also applied to capillary array electrophoresis. The use of cheaper detection, and the elimination of purification of DNA sample before or after PCR reaction, will make this approach an

  15. Application of industrial hygiene techniques for work-place exposure assessment protocols related to petro-chemical exploration and production field activities

    International Nuclear Information System (INIS)

    Koehn, J.

    1995-01-01

    Standard industrial hygiene techniques for recognition, evaluation, and control can be directly applied to development of technical protocols for workplace exposure assessment activities for a variety of field site locations. Categories of occupational hazards include chemical and physical agents. Examples of these types of hazards directly related to oil and gas exploration and production workplaces include hydrocarbons, benzene, oil mist, hydrogen sulfide, Naturally Occurring Radioactive Materials (NORM), asbestos-containing materials, and noise. Specific components of well process chemicals include potential hazardous chemical substances such as methanol, acrolein, chlorine dioxide, and hydrochloric acid. Other types of exposure hazards may result from non-routine conduct of sandblasting and painting operations

  16. Sample-interpolation timing: an optimized technique for the digital measurement of time of flight for γ rays and neutrons at relatively low sampling rates

    International Nuclear Information System (INIS)

    Aspinall, M D; Joyce, M J; Mackin, R O; Jarrah, Z; Boston, A J; Nolan, P J; Peyton, A J; Hawkes, N P

    2009-01-01

    A unique, digital time pick-off method, known as sample-interpolation timing (SIT) is described. This method demonstrates the possibility of improved timing resolution for the digital measurement of time of flight compared with digital replica-analogue time pick-off methods for signals sampled at relatively low rates. Three analogue timing methods have been replicated in the digital domain (leading-edge, crossover and constant-fraction timing) for pulse data sampled at 8 GSa s −1 . Events arising from the 7 Li(p, n) 7 Be reaction have been detected with an EJ-301 organic liquid scintillator and recorded with a fast digital sampling oscilloscope. Sample-interpolation timing was developed solely for the digital domain and thus performs more efficiently on digital signals compared with analogue time pick-off methods replicated digitally, especially for fast signals that are sampled at rates that current affordable and portable devices can achieve. Sample interpolation can be applied to any analogue timing method replicated digitally and thus also has the potential to exploit the generic capabilities of analogue techniques with the benefits of operating in the digital domain. A threshold in sampling rate with respect to the signal pulse width is observed beyond which further improvements in timing resolution are not attained. This advance is relevant to many applications in which time-of-flight measurement is essential

  17. Determination of structure of oriented samples using two-dimensional solid state NMR techniques

    International Nuclear Information System (INIS)

    Jin Hong; Harbison, G.S.

    1990-01-01

    One dimensional and two-dimensional MAS techniques can give detailed information about the structure and dynamics of oriented systems. We describe the application of such techniques to the liquid-crystalline polymer poly(p-phenyleneterphtalimide) (PPTA), and thence deduce the solid-state structure of the material. (author). 9 refs.; 6 figs

  18. Assessing five field sampling methods to monitor Yellowstone National Park's northern ungulate winter range: the advantages and disadvantages of implementing a new sampling protocol

    Science.gov (United States)

    Pamela G. Sikkink; Roy Renkin; Geneva Chong; Art Sikkink

    2013-01-01

    The five field sampling methods tested for this study differed in richness and Simpson's Index values calculated from the raw data. How much the methods differed, and which ones were most similar to each other, depended on which diversity measure and which type of data were used for comparisons. When the number of species (richness) was used as a measure of...

  19. ANALYTICAL TECHNIQUES FOR THE DETERMINATION OF MELOXICAM IN PHARMACEUTICAL FORMULATIONS AND BIOLOGICAL SAMPLES

    Directory of Open Access Journals (Sweden)

    Aisha Noreen

    2016-06-01

    Full Text Available Meloxicam (MX belongs to the family of oxicams which is the most important group of non steroidal anti-inflammatory drugs (NSAIDs and is widely used for their analgesics and antipyretic activities. It inhibits both COX-I and COX-II enzymes with less gastric and local tissues irritation. A number of analytical techniques have been used for the determination of MX in pharmaceutical as well as in biological fluids. These techniques include titrimetry, spectrometry, chromatography, flow injection spectrometry, fluorescence spectrometry, capillary zone electrophoresis and electrochemical techniques. Many of these techniques have also been used for the simultaneous determination of MX with other compounds. A comprehensive review of these analytical techniques has been done which could be useful for the analytical chemists and quality control pharmacists.

  20. A novel PFIB sample preparation protocol for correlative 3D X-ray CNT and FIB-TOF-SIMS tomography

    Energy Technology Data Exchange (ETDEWEB)

    Priebe, Agnieszka, E-mail: agnieszka.priebe@gmail.com [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Audoit, Guillaume; Barnes, Jean-Paul [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France)

    2017-02-15

    We present a novel sample preparation method that allows correlative 3D X-ray Computed Nano-Tomography (CNT) and Focused Ion Beam Time-Of-Flight Secondary Ion Mass Spectrometry (FIB-TOF-SIMS) tomography to be performed on the same sample. In addition, our invention ensures that samples stay unmodified structurally and chemically between the subsequent experiments. The main principle is based on modifying the topography of the X-ray CNT experimental setup before FIB-TOF-SIMS measurements by incorporating a square washer around the sample. This affects the distribution of extraction field lines and therefore influences the trajectories of secondary ions that are now guided more efficiently towards the detector. As the result, secondary ion detection is significantly improved and higher, i.e. statistically better, signals are obtained. - Highlights: • Novel sample preparation for correlative 3D X-ray CNT and FIB-TOF-SIMS is presented. • Two experiments are conducted on exactly the same sample without any modifications. • Introduction of a square washer around the sample leads to increased ion detection.

  1. Fast patient-specific Monte Carlo brachytherapy dose calculations via the correlated sampling variance reduction technique

    Energy Technology Data Exchange (ETDEWEB)

    Sampson, Andrew; Le Yi; Williamson, Jeffrey F. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

    2012-02-15

    Purpose: To demonstrate potential of correlated sampling Monte Carlo (CMC) simulation to improve the calculation efficiency for permanent seed brachytherapy (PSB) implants without loss of accuracy. Methods: CMC was implemented within an in-house MC code family (PTRAN) and used to compute 3D dose distributions for two patient cases: a clinical PSB postimplant prostate CT imaging study and a simulated post lumpectomy breast PSB implant planned on a screening dedicated breast cone-beam CT patient exam. CMC tallies the dose difference, {Delta}D, between highly correlated histories in homogeneous and heterogeneous geometries. The heterogeneous geometry histories were derived from photon collisions sampled in a geometrically identical but purely homogeneous medium geometry, by altering their particle weights to correct for bias. The prostate case consisted of 78 Model-6711 {sup 125}I seeds. The breast case consisted of 87 Model-200 {sup 103}Pd seeds embedded around a simulated lumpectomy cavity. Systematic and random errors in CMC were unfolded using low-uncertainty uncorrelated MC (UMC) as the benchmark. CMC efficiency gains, relative to UMC, were computed for all voxels, and the mean was classified in regions that received minimum doses greater than 20%, 50%, and 90% of D{sub 90}, as well as for various anatomical regions. Results: Systematic errors in CMC relative to UMC were less than 0.6% for 99% of the voxels and 0.04% for 100% of the voxels for the prostate and breast cases, respectively. For a 1 x 1 x 1 mm{sup 3} dose grid, efficiency gains were realized in all structures with 38.1- and 59.8-fold average gains within the prostate and breast clinical target volumes (CTVs), respectively. Greater than 99% of the voxels within the prostate and breast CTVs experienced an efficiency gain. Additionally, it was shown that efficiency losses were confined to low dose regions while the largest gains were located where little difference exists between the homogeneous and

  2. Sample application of sensitivity/uncertainty analysis techniques to a groundwater transport problem. National Low-Level Waste Management Program

    International Nuclear Information System (INIS)

    Seitz, R.R.; Rood, A.S.; Harris, G.A.; Maheras, S.J.; Kotecki, M.

    1991-06-01

    The primary objective of this document is to provide sample applications of selected sensitivity and uncertainty analysis techniques within the context of the radiological performance assessment process. These applications were drawn from the companion document Guidelines for Sensitivity and Uncertainty Analyses of Low-Level Radioactive Waste Performance Assessment Computer Codes (S. Maheras and M. Kotecki, DOE/LLW-100, 1990). Three techniques are illustrated in this document: one-factor-at-a-time (OFAT) analysis, fractional factorial design, and Latin hypercube sampling. The report also illustrates the differences in sensitivity and uncertainty analysis at the early and latter stages of the performance assessment process, and potential pitfalls that can be encountered when applying the techniques. The emphasis is on application of the techniques as opposed to the actual results, since the results are hypothetical and are not based on site-specific conditions

  3. Comparison of coarse coal dust sampling techniques in a laboratory-simulated longwall section.

    Science.gov (United States)

    Patts, Justin R; Barone, Teresa L

    2017-05-01

    Airborne coal dust generated during mining can deposit and accumulate on mine surfaces, presenting a dust explosion hazard. When assessing dust hazard mitigation strategies for airborne dust reduction, sampling is done in high-velocity ventilation air, which is used to purge the mining face and gallery tunnel. In this environment, the sampler inlet velocity should be matched to the air stream velocity (isokinetic sampling) to prevent oversampling of coarse dust at low sampler-to-air velocity ratios. Low velocity ratios are often encountered when using low flow rate, personal sampling pumps commonly used in underground mines. In this study, with a goal of employing mine-ready equipment, a personal sampler was adapted for area sampling of coarse coal dust in high-velocity ventilation air. This was done by adapting an isokinetic nozzle to the inlet of an Institute of Occupational Medicine (Edinburgh, Scotland) sampling cassette (IOM). Collected dust masses were compared for the modified IOM isokinetic sampler (IOM-MOD), the IOM without the isokinetic nozzle, and a conventional dust sampling cassette without the cyclone on the inlet. All samplers were operated at a flow rate typical of personal sampling pumps: 2 L/min. To ensure differences between collected masses that could be attributed to sampler design and were not influenced by artifacts from dust concentration gradients, relatively uniform and repeatable dust concentrations were demonstrated in the sampling zone of the National Institute for Occupational Safety and Health experimental mine gallery. Consistent with isokinetic theory, greater differences between isokinetic and non-isokinetic sampled masses were found for larger dust volume-size distributions and higher ventilation air velocities. Since isokinetic sampling is conventionally used to determine total dust concentration, and isokinetic sampling made a difference in collected masses, the results suggest when sampling for coarse coal dust the IOM-MOD may

  4. TU-H-207A-09: An Automated Technique for Estimating Patient-Specific Regional Imparted Energy and Dose From TCM CT Exams Across 13 Protocols

    International Nuclear Information System (INIS)

    Sanders, J; Tian, X; Segars, P; Boone, J; Samei, E

    2016-01-01

    Purpose: To develop an automated technique for estimating patient-specific regional imparted energy and dose from tube current modulated (TCM) computed tomography (CT) exams across a diverse set of head and body protocols. Methods: A library of 58 adult computational anthropomorphic extended cardiac-torso (XCAT) phantoms were used to model a patient population. A validated Monte Carlo program was used to simulate TCM CT exams on the entire library of phantoms for three head and 10 body protocols. The net imparted energy to the phantoms, normalized by dose length product (DLP), and the net tissue mass in each of the scan regions were computed. A knowledgebase containing relationships between normalized imparted energy and scanned mass was established. An automated computer algorithm was written to estimate the scanned mass from actual clinical CT exams. The scanned mass estimate, DLP of the exam, and knowledgebase were used to estimate the imparted energy to the patient. The algorithm was tested on 20 chest and 20 abdominopelvic TCM CT exams. Results: The normalized imparted energy increased with increasing kV for all protocols. However, the normalized imparted energy was relatively unaffected by the strength of the TCM. The average imparted energy was 681 ± 376 mJ for abdominopelvic exams and 274 ± 141 mJ for chest exams. Overall, the method was successful in providing patientspecific estimates of imparted energy for 98% of the cases tested. Conclusion: Imparted energy normalized by DLP increased with increasing tube potential. However, the strength of the TCM did not have a significant effect on the net amount of energy deposited to tissue. The automated program can be implemented into the clinical workflow to provide estimates of regional imparted energy and dose across a diverse set of clinical protocols.

  5. Measurement of electro-sprayed 238 and 239+240 plutonium isotopes using 4{pi}-alpha spectrometry. Application to environmental samples; Spectrometrie alpha 4{pi} de sources d'actinides realisees par electronebulisation. Developpement et optimisation d'un protocole applique au mesurage des isotopes 238 et 239+240 du plutonium dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Charmoille-Roblot, M. [CEA/Fontenay-aux-Roses, Dept. de Protection de l' Environnement (DPRE), 92 (France)]|[Paris-11 Univ., 91 - Orsay (France)

    1999-07-01

    A new protocol for plutonium deposition using the electro-spray technique coupled with 4{pi}-{alpha} spectrometry is proposed to improve the detection limit, shorten the counting time. In order to increase the detection efficiency, it was proposed to measure 238 and 239+240 plutonium isotopes electro-sprayed deposit simultaneously on both sides of the source support, that must be as transparent as possible to alpha-emissions, in a two-alpha detectors chamber. A radiochemical protocol was adapted to electro-spray constraints and a very thin carbon foil was selected for 4{pi} -alpha spectrometry. The method was applied to a batch of sediment samples and gave the same results as an electrodeposited source measured using conventional alpha spectrometry with a 25 % gain on counting time and 10 % on plutonium 238 detection limit. Validation and application of the technique have been made on reference samples. (author)

  6. Detection and identification of Leishmania spp.: application of two hsp70-based PCR-RFLP protocols to clinical samples from the New World.

    Science.gov (United States)

    Montalvo, Ana M; Fraga, Jorge; Tirado, Dídier; Blandón, Gustavo; Alba, Annia; Van der Auwera, Gert; Vélez, Iván Darío; Muskus, Carlos

    2017-07-01

    Leishmaniasis is highly prevalent in New World countries, where several methods are available for detection and identification of Leishmania spp. Two hsp70-based PCR protocols (PCR-N and PCR-F) and their corresponding restriction fragment length polymorphisms (RFLP) were applied for detection and identification of Leishmania spp. in clinical samples recruited in Colombia, Guatemala, and Honduras. A total of 93 cases were studied. The samples were classified into positive or suspected of leishmaniasis according to parasitological criteria. Molecular amplification of two different hsp70 gene fragments and further RFLP analysis for identification of Leishmania species was done. The detection in parasitologically positive samples was higher using PCR-N than PCR-F. In the total of samples studied, the main species identified were Leishmania panamensis, Leishmania braziliensis, and Leishmania infantum (chagasi). Although RFLP-N was more efficient for the identification, RFLP-F is necessary for discrimination between L. panamensis and Leishmania guyanesis, of great importance in Colombia. Unexpectedly, one sample from this country revealed an RFLP pattern corresponding to Leishmania naiffi. Both molecular variants are applicable for the study of clinical samples originated in Colombia, Honduras, and Guatemala. Choosing the better tool for each setting depends on the species circulating. More studies are needed to confirm the presence of L. naiffi in Colombian territory.

  7. Experimental-calculation technique for Ksub(IC) determination using the samples of decreased dimensions

    International Nuclear Information System (INIS)

    Vinokurov, V.A.; Dymshits, A.V.; Pirusskij, M.V.; Ovsyannikov, B.M.; Kononov, V.V.

    1981-01-01

    A possibility to decrease the size of samples, which is necessary for the reliable determination of fractUre toughness Ksub(1c), is established. The dependences of crack-resistance caracteristics on the sample dimensions are determined experimentally. The static bending tests are made using the 1251 model of ''Instron'' installation with a specially designed device. The samples of the 20KhNMF steel have been tested. It is shown that the Ksub(1c) value, determined for the samples with the largest netto cross section (50x100 rm), is considerably lower than Ksub(1c) values, determined for the samples with the decreased sizes. it is shown that the developed experimental-calculated method of Ksub(1c) determination can be practically used for the samples of the decreased sizes with the introduction of the corresponding amendment coefficient [ru

  8. Electromembrane extraction as a rapid and selective miniaturized sample preparation technique for biological fluids

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Pedersen-Bjergaard, Stig; Seip, Knut Fredrik

    2015-01-01

    This special report discusses the sample preparation method electromembrane extraction, which was introduced in 2006 as a rapid and selective miniaturized extraction method. The extraction principle is based on isolation of charged analytes extracted from an aqueous sample, across a thin film....... Technical aspects of electromembrane extraction, important extraction parameters as well as a handful of examples of applications from different biological samples and bioanalytical areas are discussed in the paper....

  9. Evaluation of FASP, SP3, and iST Protocols for Proteomic Sample Preparation in the Low Microgram Range.

    Science.gov (United States)

    Sielaff, Malte; Kuharev, Jörg; Bohn, Toszka; Hahlbrock, Jennifer; Bopp, Tobias; Tenzer, Stefan; Distler, Ute

    2017-11-03

    Efficient and reproducible sample preparation is a prerequisite for any robust and sensitive quantitative bottom-up proteomics workflow. Here, we performed an independent comparison between single-pot solid-phase-enhanced sample preparation (SP3), filter-aided sample preparation (FASP), and a commercial kit based on the in-StageTip (iST) method. We assessed their performance for the processing of proteomic samples in the low μg range using varying amounts of HeLa cell lysate (1-20 μg of total protein). All three workflows showed similar performances for 20 μg of starting material. When handling sample sizes below 10 μg, the number of identified proteins and peptides as well as the quantitative reproducibility and precision drastically dropped in case of FASP. In contrast, SP3 and iST provided high proteome coverage even in the low μg range. Even when digesting 1 μg of starting material, both methods still enabled the identification of over 3000 proteins and between 25 000 and 30 000 peptides. On average, the quantitative reproducibility between experimental replicates was slightly higher in case of SP3 (R 2 = 0.97 (SP3); R 2 = 0.93 (iST)). Applying SP3 toward the characterization of the proteome of FACS-sorted tumor-associated macrophages in the B16 tumor model enabled the quantification of 2965 proteins and revealed a "mixed" M1/M2 phenotype.

  10. Techniques and Protocols for Dispersing Nanoparticle Powders in Aqueous Media—is there a Rationale for Harmonization?

    DEFF Research Database (Denmark)

    Hartmann, Nanna B.; Jensen, Keld Alstrup; Baun, Anders

    2015-01-01

    scientific studies and from consensus reached in larger scale research projects and international organizations. A step-wise approach is proposed to develop tailored dispersion protocols for ecotoxicological and mammalian toxicological testing of ENP. The recommendations of this analysis may serve as a guide......Selecting appropriate ways of bringing engineered nanoparticles (ENP) into aqueous dispersion is a main obstacle for testing, and thus for understanding and evaluating, their potential adverse effects to the environment and human health. Using different methods to prepare (stock) dispersions...... of the same ENP may be a source of variation in the toxicity measured. Harmonization and standardization of dispersion methods applied in mammalian and ecotoxicity testing are needed to ensure a comparable data quality and to minimize test artifacts produced by modifications of ENP during the dispersion...

  11. Tulsa 1000: a naturalistic study protocol for multilevel assessment and outcome prediction in a large psychiatric sample.

    Science.gov (United States)

    Victor, Teresa A; Khalsa, Sahib S; Simmons, W Kyle; Feinstein, Justin S; Savitz, Jonathan; Aupperle, Robin L; Yeh, Hung-Wen; Bodurka, Jerzy; Paulus, Martin P

    2018-01-24

    Although neuroscience has made tremendous progress towards understanding the basic neural circuitry underlying important processes such as attention, memory and emotion, little progress has been made in applying these insights to psychiatric populations to make clinically meaningful treatment predictions. The overall aim of the Tulsa 1000 (T-1000) study is to use the NIMH Research Domain Criteria framework in order to establish a robust and reliable dimensional set of variables that quantifies the positive and negative valence, cognition and arousal domains, including interoception, to generate clinically useful treatment predictions. The T-1000 is a naturalistic study that will recruit, assess and longitudinally follow 1000 participants, including healthy controls and treatment-seeking individuals with mood, anxiety, substance use and eating disorders. Each participant will undergo interview, behavioural, biomarker and neuroimaging assessments over the course of 1 year. The study goal is to determine how disorders of affect, substance use and eating behaviour organise across different levels of analysis (molecules, genes, cells, neural circuits, physiology, behaviour and self-report) to predict symptom severity, treatment outcome and long-term prognosis. The data will be used to generate computational models based on Bayesian statistics. The final end point of this multilevel latent variable analysis will be standardised assessments that can be developed into clinical tools to help clinicians predict outcomes and select the best intervention for each individual, thereby reducing the burden of mental disorders, and taking psychiatry a step closer towards personalised medicine. Ethical approval was obtained from Western Institutional Review Board screening protocol #20101611. The dissemination plan includes informing health professionals of results for clinical practice, submitting results to journals for peer-reviewed publication, presenting results at national

  12. Behavioural sampling techniques and activity pattern of Indian Pangolin Manis crassicaudata (Mammalia: Manidae in captivity

    Directory of Open Access Journals (Sweden)

    R.K. Mohapatra

    2013-12-01

    Full Text Available The study presents data on six Indian Pangolins Manis crassicaudata observed in captivity at the Pangolin Conservation Breeding Centre, Nandankanan, Odisha, India over 1377 hours of video recordings for each pangolin between 1500hr and 0800hr on 81 consecutive observational days. Video recordings were made through digital systems assisted by infrared enabled CCTV cameras. The data highlights patterns relate to 12 different behaviour and enclosure utilization. Different interval periods for sampling of instantaneous behaviour from video recordings have been evaluated to develop optimal study methods for the future. The activity budgets of pangolins displayed natural patterns of nocturnal activity with a peak between 20:00-21:00 hr. When out of their burrow, they spent about 59% of the time walking in the enclosure, and 14% of the time feeding. The repeatability of the behaviours has a significant negative correlation with the mean time spent in that behaviour. Focal behavioural samples significantly correlated with instantaneous samples up to 15 minutes interval. The correlation values gradually decreased with the increase in sampling interval. The results indicate that results obtained from focal sampling and instantaneous sampling with relatively shorter intervals (=5 minutes are about equally reliable. The study suggests use of focal sampling, instead of instantaneous sampling to record behaviour relating to social interactions.

  13. Analysis of techniques of sample attack for soil and mineral analysis

    International Nuclear Information System (INIS)

    Dean, J.R.; Chiu, N.W.

    1985-05-01

    Four methods of sample attack were evaluated in the laboratory for use in the determination of uranium, radium-226, thorium-232, thorium-230, thorium-228, and lead-210. The methods evaluated were (1) KF/pyrosulfate fusion; (2) Sodium carbonate fusion; (3) Nitric, perchloric, hydrofluoric acid digestion; and, (4) combination nitric, perchloric, hydrofluoric acid/pyrosulfate fusion. Five samples were chosen for evaluation; two were mine tailings from Bancroft, Ontario and Beaverlodge, Saskatchewan, one was a synthetic uranium ore-silica mixture and two were soil samples supplied by AECB. The KF/pyrosulfate dissolution procedure was found to be the fastest and, overall, most accurate dissolution method for the analysis of 1-20 samples. For larger numbers of samples the three acid/pyrosulfate fusion combination was shown to have some merit

  14. Uranium, radium and radon exhalation study in some soil samples using track etch technique

    International Nuclear Information System (INIS)

    Harmanjit, Singh; Joga, Singh; Surinder, Singh; Bajwa, B.S.

    2006-01-01

    Full text of publication follows: Uranium, radium concentration and radon exhalation rates have been determined in the soil samples collected from some areas of Punjab using the L.R.-115 nuclear track detectors. Radium concentration in these samples has been found to be varying from 0.80 to 5.34 Bq Kg-1. The radon exhalation rate in these samples has been found to be varying from 0.99 to 6.60 mBq Kg -1 h -1 (32.82 to 218.49 mBqm -2 h -1 ). A good correlation has been observed between radon exhalation rate and radium concentration observed in the soil samples. The uranium concentration in all these samples is being carried out and the other correlations will also be established. (authors)

  15. Evaluation of oxidation techniques for preparing bioassay and environmental samples for liquid scintillation counting

    International Nuclear Information System (INIS)

    Miller, H.H.

    1979-10-01

    In environmental and biological monitoring for carbon-14 and tritium, the presence of color and chemical quenching agents in the samples can degrade the efficiency of liquid scintillation counting. A series of experiments was performed to evaluate the usefulness, under routine conditions, of first oxidizing the samples to improve the counting by removing the color and quenching agents. The scintillation counter was calibrated for the effects of quenching agents on its counting efficiency. Oxidizing apparatus was tested for its ability to accurately recover the 14 C and 3 H in the samples. Scintillation counting efficiences were compared for a variety of oxidized and unoxidized environmental and bioassay samples. The overall conclusion was that, for routine counting, oxidation of such samples is advantageous when they are highly quenched or in solid form

  16. Percutaneous CT-guided sacroiliac joint sampling for infection: aspiration, biopsy, and technique.

    Science.gov (United States)

    Knipp, David; Simeone, F Joseph; Nelson, Sandra B; Huang, Ambrose J; Chang, Connie Y

    2018-04-01

    To evaluate methods of CT-guided sacroiliac joint sampling in patients with suspected infection. All CT-guided sacroiliac joint sampling procedures for suspected infection were reviewed for sampling type (aspiration, lavage aspiration, biopsy), microbiology results, and clinical and imaging follow-up. The primary gold standard was anatomic pathology. If pathology was not available, then positive blood culture with the same organism as SIJ sampling, imaging and clinical follow-up, or clinical follow-up only were used. Anterior and posterior joint distention was evaluated by MRI within 7 days of the procedure. A total of 34 patients (age 39 ± 20 (range, 6-75) years; 21 F, 13 M) were included. Aspiration samples only were obtained in 13/34 (38%) cases, biopsy samples only in 9/34 (26%) cases, and both samples in 12/34 (35%) cases. There was an overall 54% sensitivity and 86% specificity. For the aspiration samples, sensitivity and specificity were 60 and 81%, respectively, compared to 45 and 90% for the biopsy samples. In cases with both samples, biopsy did not add additional microbial information. Seventeen (17/34, 50%) patients had an MRI. The anterior joint was more distended than the posterior joint in 15/17 (88%) of patients, and this difference was significant (P = 0.0003). All of these 17 patients had an attempted aspiration by a posterior approach; 6/17 (35%) resulted in a successful aspiration. Aspiration of the sacroiliac joint has a higher sensitivity than biopsy and should always be attempted first. MRI may be helpful for procedure planning.

  17. Percutaneous CT-guided sacroiliac joint sampling for infection. Aspiration, biopsy, and technique

    Energy Technology Data Exchange (ETDEWEB)

    Knipp, David; Simeone, F.J.; Huang, Ambrose J.; Chang, Connie Y. [Massachusetts General Hospital, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States); Nelson, Sandra B. [Massachusetts General Hospital, Infectious Disease Unit, Department of Medicine, Boston, MA (United States)

    2018-04-15

    To evaluate methods of CT-guided sacroiliac joint sampling in patients with suspected infection. All CT-guided sacroiliac joint sampling procedures for suspected infection were reviewed for sampling type (aspiration, lavage aspiration, biopsy), microbiology results, and clinical and imaging follow-up. The primary gold standard was anatomic pathology. If pathology was not available, then positive blood culture with the same organism as SIJ sampling, imaging and clinical follow-up, or clinical follow-up only were used. Anterior and posterior joint distention was evaluated by MRI within 7 days of the procedure. A total of 34 patients (age 39 ± 20 (range, 6-75) years; 21 F, 13 M) were included. Aspiration samples only were obtained in 13/34 (38%) cases, biopsy samples only in 9/34 (26%) cases, and both samples in 12/34 (35%) cases. There was an overall 54% sensitivity and 86% specificity. For the aspiration samples, sensitivity and specificity were 60 and 81%, respectively, compared to 45 and 90% for the biopsy samples. In cases with both samples, biopsy did not add additional microbial information. Seventeen (17/34, 50%) patients had an MRI. The anterior joint was more distended than the posterior joint in 15/17 (88%) of patients, and this difference was significant (P = 0.0003). All of these 17 patients had an attempted aspiration by a posterior approach; 6/17 (35%) resulted in a successful aspiration. Aspiration of the sacroiliac joint has a higher sensitivity than biopsy and should always be attempted first. MRI may be helpful for procedure planning. (orig.)

  18. New Equipment and Techniques for Remote Sampling of Stored Radioactive Waste

    International Nuclear Information System (INIS)

    Nance, T.A.

    2001-01-01

    Radioactive waste is stored at the Savannah River Site (SRS), part of the Department of Energy (DOE) complex. This radioactive waste is stored in buried tanks and management of the waste requires several processes, including material addition, heating, cooling, mixing, and transfer from tank to tank. During waste processing, it is necessary to know the chemical components and their characteristics to determine the steps necessary to maintain the waste form or to manipulate the waste into the form desired. Waste characterization begins by obtaining a sample for analysis. High level radioactive waste sampling is routinely done with simple, standard samplers such as a dip sample. Other sampling is non-routine or specialized, with unique, special requirements, such as sampling remote areas that are difficult to reach. Other specialized sampling includes sampling materials with unknown characteristics or material that must be gathered to obtain an adequate sample or materials that must be broken up to sample or forcibly separated from the tank. The samplers described in this paper are specialized samplers. These samplers include the Dip Filter Sampler, Soft Core Sampler, Hard Core Sampler, Circle Scrape Sampler, Small Scrape Sampler, Suction and Strain Sampler, and Vial Snapper Sampler. The Dip Filter Sampler is used to sample floating particulate matter or floating organic matter. The Soft Core Sampler and Hard Core Sampler are used to obtain samples of solids from the tank floor. The Soft Core Sampler is used on soft solids such as sludge and saltcake and the Hard Core Sampler on hardened solid deposits. The Circle Scrape Sampler is used to obtain solid samples through a small entry riser and out from under the riser. The Small Scrape Sampler enters a small entry riser and is used to scrape a sample from the tank wall. The Suction and Strain Sampler is used to gather a remote submerged sample or filter a solid sample from supernate. The Vial Snapper Grab Sampler is

  19. Advanced sampling techniques for hand-held FT-IR instrumentation

    Science.gov (United States)

    Arnó, Josep; Frunzi, Michael; Weber, Chris; Levy, Dustin

    2013-05-01

    FT-IR spectroscopy is the technology of choice to identify solid and liquid phase unknown samples. The challenging ConOps in emergency response and military field applications require a significant redesign of the stationary FT-IR bench-top instruments typically used in laboratories. Specifically, field portable units require high levels of resistance against mechanical shock and chemical attack, ease of use in restrictive gear, extreme reliability, quick and easy interpretation of results, and reduced size. In the last 20 years, FT-IR instruments have been re-engineered to fit in small suitcases for field portable use and recently further miniaturized for handheld operation. This article introduces the HazMatID™ Elite, a FT-IR instrument designed to balance the portability advantages of a handheld device with the performance challenges associated with miniaturization. In this paper, special focus will be given to the HazMatID Elite's sampling interfaces optimized to collect and interrogate different types of samples: accumulated material using the on-board ATR press, dispersed powders using the ClearSampler™ tool, and the touch-to-sample sensor for direct liquid sampling. The application of the novel sample swipe accessory (ClearSampler) to collect material from surfaces will be discussed in some detail. The accessory was tested and evaluated for the detection of explosive residues before and after detonation. Experimental results derived from these investigations will be described in an effort to outline the advantages of this technology over existing sampling methods.

  20. Geospatial techniques for developing a sampling frame of watersheds across a region

    Science.gov (United States)

    Gresswell, Robert E.; Bateman, Douglas S.; Lienkaemper, George; Guy, T.J.

    2004-01-01

    Current land-management decisions that affect the persistence of native salmonids are often influenced by studies of individual sites that are selected based on judgment and convenience. Although this approach is useful for some purposes, extrapolating results to areas that were not sampled is statistically inappropriate because the sampling design is usually biased. Therefore, in recent investigations of coastal cutthroat trout (Oncorhynchus clarki clarki) located above natural barriers to anadromous salmonids, we used a methodology for extending the statistical scope of inference. The purpose of this paper is to apply geospatial tools to identify a population of watersheds and develop a probability-based sampling design for coastal cutthroat trout in western Oregon, USA. The population of mid-size watersheds (500-5800 ha) west of the Cascade Range divide was derived from watershed delineations based on digital elevation models. Because a database with locations of isolated populations of coastal cutthroat trout did not exist, a sampling frame of isolated watersheds containing cutthroat trout had to be developed. After the sampling frame of watersheds was established, isolated watersheds with coastal cutthroat trout were stratified by ecoregion and erosion potential based on dominant bedrock lithology (i.e., sedimentary and igneous). A stratified random sample of 60 watersheds was selected with proportional allocation in each stratum. By comparing watershed drainage areas of streams in the general population to those in the sampling frame and the resulting sample (n = 60), we were able to evaluate the how representative the subset of watersheds was in relation to the population of watersheds. Geospatial tools provided a relatively inexpensive means to generate the information necessary to develop a statistically robust, probability-based sampling design.

  1. Effect of DNA extraction methods and sampling techniques on the apparent structure of cow and sheep rumen microbial communities.

    Directory of Open Access Journals (Sweden)

    Gemma Henderson

    Full Text Available Molecular microbial ecology techniques are widely used to study the composition of the rumen microbiota and to increase understanding of the roles they play. Therefore, sampling and DNA extraction methods that result in adequate yields of microbial DNA that also accurately represents the microbial community are crucial. Fifteen different methods were used to extract DNA from cow and sheep rumen samples. The DNA yield and quality, and its suitability for downstream PCR amplifications varied considerably, depending on the DNA extraction method used. DNA extracts from nine extraction methods that passed these first quality criteria were evaluated further by quantitative PCR enumeration of microbial marker loci. Absolute microbial numbers, determined on the same rumen samples, differed by more than 100-fold, depending on the DNA extraction method used. The apparent compositions of the archaeal, bacterial, ciliate protozoal, and fungal communities in identical rumen samples were assessed using 454 Titanium pyrosequencing. Significant differences in microbial community composition were observed between extraction methods, for example in the relative abundances of members of the phyla Bacteroidetes and Firmicutes. Microbial communities in parallel samples collected from cows by oral stomach-tubing or through a rumen fistula, and in liquid and solid rumen digesta fractions, were compared using one of the DNA extraction methods. Community representations were generally similar, regardless of the rumen sampling technique used, but significant differences in the abundances of some microbial taxa such as the Clostridiales and the Methanobrevibacter ruminantium clade were observed. The apparent microbial community composition differed between rumen sample fractions, and Prevotellaceae were most abundant in the liquid fraction. DNA extraction methods that involved phenol-chloroform extraction and mechanical lysis steps tended to be more comparable. However

  2. Evaluation of alternative macroinvertebrate sampling techniques for use in a new tropical freshwater bioassessment scheme

    Directory of Open Access Journals (Sweden)

    Isabel Eleanor Moore

    2015-06-01

    Full Text Available Aim: The study aimed to determine the effectiveness of benthic macroinvertebrate dredge net sampling procedures as an alternative method to kick net sampling in tropical freshwater systems, specifically as an evaluation of sampling methods used in the Zambian Invertebrate Scoring System (ZISS river bioassessment scheme. Tropical freshwater ecosystems are sometimes dangerous or inaccessible to sampling teams using traditional kick-sampling methods, so identifying an alternative procedure that produces similar results is necessary in order to collect data from a wide variety of habitats.MethodsBoth kick and dredge nets were used to collect macroinvertebrate samples at 16 riverine sites in Zambia, ranging from backwaters and floodplain lagoons to fast flowing streams and rivers. The data were used to calculate ZISS, diversity (S: number of taxa present, and Average Score Per Taxon (ASPT scores per site, using the two sampling methods to compare their sampling effectiveness. Environmental parameters, namely pH, conductivity, underwater photosynthetically active radiation (PAR, temperature, alkalinity, flow, and altitude, were also recorded and used in statistical analysis. Invertebrate communities present at the sample sites were determined using multivariate procedures.ResultsAnalysis of the invertebrate community and environmental data suggested that the testing exercise was undertaken in four distinct macroinvertebrate community types, supporting at least two quite different macroinvertebrate assemblages, and showing significant differences in habitat conditions. Significant correlations were found for all three bioassessment score variables between results acquired using the two methods, with dredge-sampling normally producing lower scores than did the kick net procedures. Linear regression models were produced in order to correct each biological variable score collected by a dredge net to a score similar to that of one collected by kick net

  3. Dosimetric characterization of BeO samples in alpha, beta and X radiation beams using luminescent techniques

    International Nuclear Information System (INIS)

    Groppo, Daniela Piai

    2013-01-01

    In the medical field, the ionizing radiation is used both for therapeutic and diagnostic purposes, in a wide range of radiation doses. In order to ensure that the objective is achieved in practice, detailed studies of detectors and devices in different types of radiations beams are necessary. In this work a dosimetric characterization of BeO samples was performed using the techniques of thermoluminescence (TL) and optically stimulated luminescence (OSL) by a comparison of their response for alpha, beta and X radiations and the establishment of an appropriated system for use in monitoring of these radiations beams. The main results are: the high sensitivity to beta radiation for both techniques, good reproducibility of TL and OSL response (coefficients of variation lower than 5%), maximum energy dependence of the X radiation of 28% for the TL technique, and only 7% for the OSL technique, within the studied energy range. The dosimetric characteristics obtained in this work show the possibility of applying BeO samples to dosimetry of alpha, beta and X radiations, considering the studied dose ranges, using the TL and OSL techniques. From the results obtained, the samples of BeO showed their potential use for beam dosimetry in diagnostic radiology and radiotherapy. (author)

  4. An evaluation of sampling methods and supporting techniques for tackling lead in drinking water in Aberta Province

    Science.gov (United States)

    A collaborative project commenced in August 2013 with the aim of demonstrating a range of techniques that can be used in tackling the problems of lead in drinking water. The main project was completed in March 2014, with supplementary sampling exercises in mid-2014. It involved t...

  5. The alkali halide disk technique in infra-red spectrometry : Anomalous behaviour of some samples dispersed in alkali halide disks

    NARCIS (Netherlands)

    Tolk, A.

    1961-01-01

    Some difficulties encountered in the application of the alkali halide disk technique in infra-red spectrometry are discussed. Complications due to interaction of the sample with the alkali halide have been studied experimentally. It was found that the anomalous behaviour of benzoic acid, succinic

  6. Self-collected versus clinician-collected sampling for sexually transmitted infections: a systematic review and meta-analysis protocol.

    Science.gov (United States)

    Taylor, Darlene; Lunny, Carole; Wong, Tom; Gilbert, Mark; Li, Neville; Lester, Richard; Krajden, Mel; Hoang, Linda; Ogilvie, Gina

    2013-10-10

    Three meta-analyses and one systematic review have been conducted on the question of whether self-collected specimens are as accurate as clinician-collected specimens for STI screening. However, these reviews predate 2007 and did not analyze rectal or pharyngeal collection sites. Currently, there is no consensus on which sampling method is the most effective for the diagnosis of genital chlamydia (CT), gonorrhea (GC) or human papillomavirus (HPV) infection. Our meta-analysis aims to be comprehensive in that it will examine the evidence of whether self-collected vaginal, urine, pharyngeal and rectal specimens provide as accurate a clinical diagnosis as clinician-collected samples (reference standard). Eligible studies include both randomized and non-randomized controlled trials, pre- and post-test designs, and controlled observational studies. The databases that will be searched include the Cochrane Database of Systematic Reviews, Web of Science, Database of Abstracts of Reviews of Effects (DARE), EMBASE and PubMed/Medline. Data will be abstracted independently by two reviewers using a standardized pre-tested data abstraction form. Heterogeneity will be assessed using the Q2 test. Sensitivity and specificity estimates with 95% confidence intervals as well as negative and positive likelihood ratios will be pooled and weighted using random effects meta-analysis, if appropriate. A hierarchical summary receiver operating characteristics curve for self-collected specimens will be generated. This synthesis involves a meta-analysis of self-collected samples (urine, vaginal, pharyngeal and rectal swabs) versus clinician-collected samples for the diagnosis of CT, GC and HPV, the most prevalent STIs. Our systematic review will allow patients, clinicians and researchers to determine the diagnostic accuracy of specimens collected by patients compared to those collected by clinicians in the detection of chlamydia, gonorrhea and HPV.

  7. Benchmarking sample preparation/digestion protocols reveals tube-gel being a fast and repeatable method for quantitative proteomics.

    Science.gov (United States)

    Muller, Leslie; Fornecker, Luc; Van Dorsselaer, Alain; Cianférani, Sarah; Carapito, Christine

    2016-12-01

    Sample preparation, typically by in-solution or in-gel approaches, has a strong influence on the accuracy and robustness of quantitative proteomics workflows. The major benefit of in-gel procedures is their compatibility with detergents (such as SDS) for protein solubilization. However, SDS-PAGE is a time-consuming approach. Tube-gel (TG) preparation circumvents this drawback as it involves directly trapping the sample in a polyacrylamide gel matrix without electrophoresis. We report here the first global label-free quantitative comparison between TG, stacking gel (SG), and basic liquid digestion (LD). A series of UPS1 standard mixtures (at 0.5, 1, 2.5, 5, 10, and 25 fmol) were spiked in a complex yeast lysate background. TG preparation allowed more yeast proteins to be identified than did the SG and LD approaches, with mean numbers of 1979, 1788, and 1323 proteins identified, respectively. Furthermore, the TG method proved equivalent to SG and superior to LD in terms of the repeatability of the subsequent experiments, with mean CV for yeast protein label-free quantifications of 7, 9, and 10%. Finally, known variant UPS1 proteins were successfully detected in the TG-prepared sample within a complex background with high sensitivity. All the data from this study are accessible on ProteomeXchange (PXD003841). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Green Aspects of Techniques for the Determination of Currently Used Pesticides in Environmental Samples

    OpenAIRE

    Maciej Tankiewicz; Jacek Namieśnik; Jolanta Stocka; Marek Biziuk

    2011-01-01

    Pesticides are among the most dangerous environmental pollutants because of their stability, mobility and long-term effects on living organisms. Their presence in the environment is a particular danger. It is therefore crucial to monitor pesticide residues using all available analytical methods. The analysis of environmental samples for the presence of pesticides is very difficult: the processes involved in sample preparation are labor-intensive and time-consuming. To date, it has been standa...

  9. Sample Preparation for Determination of Biological Thiols by Liquid Chromatography and Electromigration Techniques

    OpenAIRE

    Bald, Edward

    2004-01-01

    Wydrukowano z dostarczonych Wydawnictwu UŁ gotowych materiałów Majority of the bioanalytical or environmental methods do not use just one chromatografie or electrophoretic step, but rather involve several sample pretreatment steps which simplfy the matrix, and often preconcentrate and chemically modify the analytes. This work surveys typical procedures for sample preparation for most commonly analyzed biofluids with particular emphasis placed on chemical derivatization of su...

  10. A novel fluorescent in situ hybridization technique for detection of Rickettsia spp. in archival samples

    DEFF Research Database (Denmark)

    Svendsen, Claus Bo; Boye, Mette; Struve, Carsten

    2009-01-01

    A novel, sensitive and specific method for detecting Rickettsia spp. in archival samples is described. The method involves the use of fluorescently marked oligonucleotide probes for in situ hybridization. Specific hybridization of Ricekttsia was found without problems of cross-reactions with bact......A novel, sensitive and specific method for detecting Rickettsia spp. in archival samples is described. The method involves the use of fluorescently marked oligonucleotide probes for in situ hybridization. Specific hybridization of Ricekttsia was found without problems of cross...

  11. Internal Stress Distribution Measurement of TIG Welded SUS304 Samples Using Neutron Diffraction Technique

    Science.gov (United States)

    Muslih, M. Refai; Sumirat, I.; Sairun; Purwanta

    2008-03-01

    The distribution of residual stress of SUS304 samples that were undergone TIG welding process with four different electric currents has been measured. The welding has been done in the middle part of the samples that was previously grooved by milling machine. Before they were welded the samples were annealed at 650 degree Celsius for one hour. The annealing process was done to eliminate residual stress generated by grooving process so that the residual stress within the samples was merely produced from welding process. The calculation of distribution of residual stress was carried out by measuring the strains within crystal planes of Fe(220) SUS304. Strain, Young modulus, and Poisson ratio of Fe(220) SUS304 were measured using DN1-M neutron diffractometer. Young modulus and Poisson ratio of Fe(220) SUS304 sample were measured in-situ. The result of calculations showed that distribution of residual stress of SUS304 in the vicinity of welded area is influenced both by treatments given at the samples-making process and by the electric current used during welding process.

  12. Temporal and social contexts of heroin-using populations. An illustration of the snowball sampling technique.

    Science.gov (United States)

    Kaplan, C D; Korf, D; Sterk, C

    1987-09-01

    Snowball sampling is a method that has been used in the social sciences to study sensitive topics, rare traits, personal networks, and social relationships. The method involves the selection of samples utilizing "insider" knowledge and referral chains among subjects who possess common traits that are of research interest. It is especially useful in generating samples for which clinical sampling frames may be difficult to obtain or are biased in some way. In this paper, snowball samples of heroin users in two Dutch cities have been analyzed for the purpose of providing descriptions and limited inferences about the temporal and social contexts of their lifestyles. Two distinct heroin-using populations have been discovered who are distinguished by their life cycle stage. Significant contextual explanations have been found involving the passage from adolescent peer group to criminal occupation, the functioning of network "knots" and "outcroppings," and the frequency of social contact. It is suggested that the snowball sampling method may have utility in studying the temporal and social contexts of other populations of clinical interest.

  13. Detection of Chlamydophila psittaci from feral pigeons in environmental samples: problems with currently available techniques.

    Science.gov (United States)

    Geigenfeind, Ila; Haag-Wackernagel, Daniel

    2010-03-01

    Chlamydophila psittaci (Lillie, 1930) Everett et al., 1999, the pathogenic agent of human ornithosis, is widespread in feral pigeon populations and many cases of transmission from feral pigeons to humans have been reported. The aim of the present study was to detect C. psittaci in environmental samples to find out more about possible transmission routes and, therefore, to assess the zoonotic risk for humans. Fecal samples were collected from nest boxes in a feral pigeon loft. Additionally, samples were taken from the feather dust film covering the water surface of public fountains where pigeons regularly bathe. The samples were tested for the presence of chlamydial antigen using an antigen enzyme-linked immunosorbent assay to prove shedding of C. psittaci by feral pigeons. This test detects a genus specific lipopolysaccharide in the outer membrane of the chlamydial bacteria. Samples were tested using the IDEIA PCE Chlamydia Test kit (DakoCytomation) and positive results were verified with IDEIA Chlamydia Blocking Reagents (DakoCytomation). The IDEIA PCE Chlamydia Test yields a high proportion of positive results. However, when IDEIA Chlamydia Blocking was performed, most of the positive results turned out to be negative or could not be interpreted. We conclude that antigen-enzyme-linked immunosorbent assay tests are not suitable for detecting C. psittaci in environmental samples. Previous publications where no blocking test was used should be reconsidered critically. © 2010 ISZS, Blackwell Publishing and IOZ/CAS.

  14. An orientation-space super sampling technique for six-dimensional diffraction contrast tomography

    NARCIS (Netherlands)

    N.R. Viganò (Nicola); K.J. Batenburg (Joost); W. Ludwig (Wolfgang)

    2016-01-01

    textabstractDiffraction contrast tomography (DCT) is an X-ray full-field imaging technique that allows for the non-destructive three-dimensional investigation of polycrystalline materials and the determination of the physical and morphological properties of their crystallographic domains, called

  15. Detecting in situ copepod diet diversity using molecular technique: development of a copepod/symbiotic ciliate-excluding eukaryote-inclusive PCR protocol.

    Science.gov (United States)

    Hu, Simin; Guo, Zhiling; Li, Tao; Carpenter, Edward J; Liu, Sheng; Lin, Senjie

    2014-01-01

    Knowledge of in situ copepod diet diversity is crucial for accurately describing pelagic food web structure but is challenging to achieve due to lack of an easily applicable methodology. To enable analysis with whole copepod-derived DNAs, we developed a copepod-excluding 18S rDNA-based PCR protocol. Although it is effective in depressing amplification of copepod 18S rDNA, its applicability to detect diverse eukaryotes in both mono- and mixed-species has not been demonstrated. Besides, the protocol suffers from the problem that sequences from symbiotic ciliates are overrepresented in the retrieved 18S rDNA libraries. In this study, we designed a blocking primer to make a combined primer set (copepod/symbiotic ciliate-excluding eukaryote-common: CEEC) to depress PCR amplification of symbiotic ciliate sequences while maximizing the range of eukaryotes amplified. We firstly examined the specificity and efficacy of CEEC by PCR-amplifying DNAs from 16 copepod species, 37 representative organisms that are potential prey of copepods and a natural microplankton sample, and then evaluated the efficiency in reconstructing diet composition by detecting the food of both lab-reared and field-collected copepods. Our results showed that the CEEC primer set can successfully amplify 18S rDNA from a wide range of isolated species and mixed-species samples while depressing amplification of that from copepod and targeted symbiotic ciliate, indicating the universality of CEEC in specifically detecting prey of copepods. All the predetermined food offered to copepods in the laboratory were successfully retrieved, suggesting that the CEEC-based protocol can accurately reconstruct the diets of copepods without interference of copepods and their associated ciliates present in the DNA samples. Our initial application to analyzing the food composition of field-collected copepods uncovered diverse prey species, including those currently known, and those that are unsuspected, as copepod prey

  16. Direct Trace Element Analysis of Liquid Blood Samples by In-Air Ion Beam Analytical Techniques (PIXE-PIGE).

    Science.gov (United States)

    Huszank, Robert; Csedreki, László; Török, Zsófia

    2017-02-07

    There are various liquid materials whose elemental composition is of interest in various fields of science and technology. In many cases, sample preparation or the extraction can be complicated, or it would destroy the original environment before the analysis (for example, in the case of biological samples). However, multielement direct analysis of liquid samples can be realized by an external PIXE-PIGE measurement system. Particle-induced X-ray and gamma-ray emission spectroscopy (PIXE, PIGE) techniques were applied in external (in-air) microbeam configuration for the trace and main element determination of liquid samples. The direct analysis of standard solutions of several metal salts and human blood samples (whole blood, blood serum, blood plasma, and formed elements) was realized. From the blood samples, Na, P, S, Cl, K, Ca, Fe, Cu, Zn, and Br elemental concentrations were determined. The focused and scanned ion beam creates an opportunity to analyze very small volume samples (∼10 μL). As the sample matrix consists of light elements, the analysis is possible at ppm level. Using this external beam setup, it was found that it is possible to determine elemental composition of small-volume liquid samples routinely, while the liquid samples do not require any preparation processes, and thus, they can be analyzed directly. In the case of lower concentrations, the method is also suitable for the analysis (down to even ∼1 ppm level) but with less accuracy and longer measurement times.

  17. A Simplified Whole-Organ CT Perfusion Technique with Biphasic Acquisition: Preliminary Investigation of Accuracy and Protocol Feasibility in Kidneys.

    Science.gov (United States)

    Yuan, XiaoDong; Zhang, Jing; Quan, ChangBin; Tian, Yuan; Li, Hong; Ao, GuoKun

    2016-04-01

    To determine the feasibility and accuracy of a protocol for calculating whole-organ renal perfusion (renal blood flow [RBF]) and regional perfusion on the basis of biphasic computed tomography (CT), with concurrent dynamic contrast material-enhanced (DCE) CT perfusion serving as the reference standard. This prospective study was approved by the institutional review board, and written informed consent was obtained from all patients. Biphasic CT of the kidneys, including precontrast and arterial phase imaging, was integrated with a first-pass dynamic volume CT protocol and performed and analyzed in 23 patients suspected of having renal artery stenosis. The perfusion value derived from biphasic CT was calculated as CT number enhancement divided by the area under the arterial input function and compared with the DCE CT perfusion data by using the paired t test, correlation analysis, and Bland-Altman plots. Correlation analysis was made between the RBF and the extent of renal artery stenosis. All postprocessing was independently performed by two observers and then averaged as the final result. Mean ± standard deviation biphasic and DCE CT perfusion data for RBF were 425.62 mL/min ± 124.74 and 419.81 mL/min ± 121.13, respectively (P = .53), and for regional perfusion they were 271.15 mL/min per 100 mL ± 82.21 and 266.33 mL/min per 100 mL ± 74.40, respectively (P = .31). Good correlation and agreement were shown between biphasic and DCE CT perfusion for RBF (r = 0.93; ±10% variation from mean perfusion data [P < .001]) and for regional perfusion (r = 0.90; ±13% variation from mean perfusion data [P < .001]). The extent of renal artery stenosis was negatively correlated with RBF with biphasic CT perfusion (r = -0.81, P = .012). Biphasic CT perfusion is clinically feasible and provides perfusion data comparable to DCE CT perfusion data at both global and regional levels in the kidney. Online supplemental material is available for this article.

  18. Determination of multi-element in marine sediment samples collected in Angola by the k0-NAA technique

    International Nuclear Information System (INIS)

    Teixeira, M.C.P.; Ho Manh Dung; Cao Dong Vu; Nguyen Thi Sy; Nguyen Thanh Binh; Vuong Huu Tan

    2006-01-01

    The marine sediment samples were designed to collect in Angola for marine environmental pollution study. The k 0 -standardization method of neutron activation analysis (k 0 -NAA) on Dalat research reactor has been developed to determine of multi-element in the Angola marine sediment samples. The samples were irradiated in cell 7-1 for short- and middle-lived nuclides and rotary specimen rack for long-lived nuclides. The irradiation facilities were characterized for neutron spectrum parameters and post-activated samples were measured on the calibrated gamma-ray spectrometers using HPGe detectors. The analytical results for 9 marine sediment samples with 27 elements: Al, As, Br, Ca, Ce,Cl, Co, Cs, Dy, Fe, Hf, I, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Sm, Th, Ti, U, V and Zn in term of mean concentration, standard deviation and their content range are shown in the report. The analytical quality assurance was done by analysis of a Japan's certified reference material namely marine sediment NMIJ-CRM-7302a. These preliminary results revealed that the k 0 -NAA technique on the Dalat research reactor is a good analytical technique for determination of multi-element in the marine sediment samples. Some heavy metals and trace elements determined in this work possibly connected to the human activities at the sampling region. (author)

  19. Extraction of Plutonium From Spiked INEEL Soil Samples Using the Ligand-Assisted Supercritical Fluid Extraction (LA-SFE) Technique

    International Nuclear Information System (INIS)

    Fox, R.V.; Mincher, B.J.; Holmes, R.G.G.

    1999-01-01

    In order to investigate the effectiveness of ligand-assisted supercritical fluid extraction for the removal of transuranic contaminations from soils an Idaho National Engineering and Environmental Laboratory (INEEL) silty-clay soil sample was obtained from near the Radioactive Waste Management Complex area and subjected to three different chemical preparations before being spiked with plutonium. The spiked INEEL soil samples were subjected to a sequential aqueous extraction procedure to determine radionuclide portioning in each sample. Results from those extractions demonstrate that plutonium consistently partitioned into the residual fraction across all three INEEL soil preparations whereas americium partitioned 73% into the iron/manganese fraction for soil preparation A, with the balance partitioning into the residual fraction. Plutonium and americium were extracted from the INEEL soil samples using a ligand-assisted supercritical fluid extraction technique. Initial supercritical fluid extraction runs produced plutonium extraction technique. Initial supercritical fluid extraction runs produced plutonium extraction efficiencies ranging from 14% to 19%. After a second round wherein the initial extraction parameters were changed, the plutonium extraction efficiencies increased to 60% and as high as 80% with the americium level in the post-extracted soil samples dropping near to the detection limits. The third round of experiments are currently underway. These results demonstrate that the ligand-assisted supercritical fluid extraction technique can effectively extract plutonium from the spiked INEEL soil preparations

  20. Laparoscopic colorectal surgery in learning curve: Role of implementation of a standardized technique and recovery protocol. A cohort study

    Directory of Open Access Journals (Sweden)

    Gaetano Luglio

    2015-06-01

    Conclusion: Proper laparoscopic colorectal surgery is safe and leads to excellent results in terms of recovery and short term outcomes, even in a learning curve setting. Key factors for better outcomes and shortening the learning curve seem to be the adoption of a standardized technique and training model along with the strict supervision of an expert colorectal surgeon.

  1. Provenance validation of polished rice samples using nuclear and isotopic analytical techniques

    International Nuclear Information System (INIS)

    Pabroa, P.C.B.; Sucgang, R.J.; Mendoza, N.D.S.; Ebihara, M.; Peña, M.

    2015-01-01

    Rice (Oryza sativa) has been considered the best staple food among all cereals and is the staple food for over 3 billion people, constituting over half of the world’s population. Elemental and isotopic analysis revealed variance between Philippine and Japanese rice. Rice samples collected in Japan and in the Philippines (market survey samples from Metro Manila, and farm harvests from Aklan province and Central Luzon) were washed, dried and ground to fine powder. Elemental analyses of the samples were carried out using instrumental neutron activation analysis (INAA) while isotopic signatures of the samples were determined using the isotope ratio mass spectrometry (IRMS). Results show that compared with the unpolished rice standard NIES CRM10b, the polished Japanese and Philippine rice sampled show reduced concentrations of elements by as much as 1/10. 1/4 , 1/5 and 1/3 for Mg, Mn, K and Na, respectively. Levels of Ca and Zn are not greatly affected. Arsenic, probably introduced from fertilizers used in rice fields is found in all the Japanese rice tested at an average concentration of 0.103 μg/g and three out of four of the Philippine rice at an average concentration of 0.70μg/g. Higher levels of Br seen in two of the Philippine rice at 14 and 34μg/g indicated probable contamination source from the pesticide methyl bromide during quarantine. Good correlation of isotopic signatures with geographical location of polished, but not for unpolished, rice samples from Central Luzon and Aklan indicated that provenance studies are best done on polished rice samples. Isotopic with of ω’”13C show signature that of a C3 plant with possible narrow distinguishable signature with Japanese rice falling within -27.5 to -28.5 while Philippine rice within -29 to -30. Rice provenance can be ascertained using elemental analysis and isotopic abundance determination as shown by the study.(author)

  2. Trace uranium analysis in geological sample by isotope dilution-alpha spectrometry and comparison with other techniques

    International Nuclear Information System (INIS)

    Shihomatsu, H.M.; Iyer, S.S.

    1988-12-01

    Establishment of uranium determination in geological samples by alpha spectrometric isotope dilution technique using 233 U tracer is described in the present work. The various steps involved in the method namely, preparation of the sample, electrodeposition, alpha spectrometry, isotope dilution, calculation of the concentration and error statistics are discussed in detail. The experimental parameters for the electrodeposition of uranium, like current density, pH concentration of the electrolyte solution, deposition time, electrode distance were all optimised based on the efficiency of the deposition. The total accuracy and precision of the IDAS using 233 U tracer in the determination of uranium in mineral and granite samples were of the order of 1 to 2% for the concentration range of 50-1500 ppm of U. Our results are compared with those obtained by others workers using similar and different techniques. (author) [pt

  3. Clinical application of microsampling versus conventional sampling techniques in the quantitative bioanalysis of antibiotics: a systematic review.

    Science.gov (United States)

    Guerra Valero, Yarmarly C; Wallis, Steven C; Lipman, Jeffrey; Stove, Christophe; Roberts, Jason A; Parker, Suzanne L

    2018-03-01

    Conventional sampling techniques for clinical pharmacokinetic studies often require the removal of large blood volumes from patients. This can result in a physiological or emotional burden, particularly for neonates or pediatric patients. Antibiotic pharmacokinetic studies are typically performed on healthy adults or general ward patients. These may not account for alterations to a patient's pathophysiology and can lead to suboptimal treatment. Microsampling offers an important opportunity for clinical pharmacokinetic studies in vulnerable patient populations, where smaller sample volumes can be collected. This systematic review provides a description of currently available microsampling techniques and an overview of studies reporting the quantitation and validation of antibiotics using microsampling. A comparison of microsampling to conventional sampling in clinical studies is included.

  4. Sampling technique for collection of expired COsub(2) in studies using naturally labelled sup(13)C in calves

    International Nuclear Information System (INIS)

    Chevalier, R.; Pelletier, G.; Gagnon, M.

    1984-01-01

    Natural isotopic labelling of animal metabolic processes presents great advantages over the use of artificially enriched compounds. These advantages include the use of natural diets, low cost and easiness of handling, sampling and disposal. Changes in the sup(13)C/sup(12)C ratio of expired COsub(2) after ingestion of a test meal containing a variable proportion of Csub(3) and/or Csub(4) plant-derived products permits measurements of the immediate oxidation of dietary carbohydrates. A breathing device for collection of expired COsub(2) and purification techniques are described. The breath-sampling device is composed of a polypropylene enclosure and a rubber bag. The rubber bag is blown up by the animal and a sample of the expired gas is transferred to a sampling glass holder in which a vacuum had been previously achieved. Sample purification of expired COsub(2) is done by differential freezing

  5. Elemental analysis of water and soil environmental samples in Tabuk area by neutron capture gamma-ray spectroscopy techniques

    International Nuclear Information System (INIS)

    Al-Aseery, Sh.M.; Alamoudi, Z.; Hassan, A.M.

    2006-01-01

    The prompt and delayed gamma-rays due to neutron capture in the nuclei of the constituent elements of three soil samples and one drinking water sample have been measured. The 252 Cf and 226 Ra/Be isotopic neutron sources are used for neutron irradiation. Also, the hyper pure germanium detection system is used. The soil samples were from Astra, Tadco and El-Gammaz farms, while the water sample was taken from Tabuk city. In case of prompt gamma-ray analysis, a total of 16 elements were identified and the concentration percentage values by weight were calculated for: C, Na, Mg, Al, Si, S, Cl,, Ca, Ti, Cr, Mn, Fe, Co, Zn, Sr ad Pb elements. A comparative study between the results obtained in this work and the results obtained by ICP-MS and EDX-Ray techniques for the same samples is given

  6. Microparticle counts in platelet-rich and platelet-free plasma, effect of centrifugation and sample-processing protocols.

    Science.gov (United States)

    Chandler, Wayne L

    2013-03-01

    This study provides the first estimates of microparticle numbers in platelet-rich plasma (PRP) from normal individuals, closer to in-vivo levels, using higher-resolution flow cytometry. We measured platelet (CD41+) and annexin V+ microparticles in fresh and frozen aliquots of PRP, platelet-poor plasma, platelet-free plasma (PFP), and microparticles isolated by high-speed centrifugation. PRP from healthy individuals contained 730,000/μl total microparticles based on light-scattering measurements. A median of 27,000/μl microparticles in PRP were of platelet origin and 120,000/μl annexin V+, and of these, 24,000/μl were dual-positive procoagulant platelet microparticles. Double centrifugation of PRP removed 99% of platelets, but also 80% of annexin V+ CD41+, 93% of annexin V+ CD41-, and 58% of annexin V- CD41+ microparticles. Loss of microparticles with centrifugation varied from individual to individual. Microparticle counts after isolation by centrifugation and double washing were not significantly different than counts in the original PFP sample, but lower than in PRP. Freeze-thawing of PFP had no effect on platelet microparticle counts, but slightly increased annexin V+, CD41- counts. Freeze-thawing of isolated washed microparticles resulted in a 30-50% increase in annexin V+ microparticles. PRP contains large numbers of cellular microparticles, including platelet and annexin V+ microparticles, which are lost to varying degrees when PRP is double centrifuged to remove platelets. Microparticles remaining in PFP can be recovered by high-speed centrifugation without loss compared to the original PFP sample. Freeze-thawing has variable effects on microparticle counts depending on the sample preparation used.

  7. Introduction to Body Composition Assessment Using the Deuterium Dilution Technique with Analysis of Urine Samples by Isotope Ratio Mass Spectrometry

    International Nuclear Information System (INIS)

    2010-01-01

    The IAEA has fostered the more widespread use of a stable isotope technique to assess body composition in different population groups to address priority areas in public health nutrition in Member States. It has done this by supporting national and regional nutrition projects through its technical cooperation programme and coordinated research projects over many years. This publication was developed by an international group of experts to provide practical hands-on guidance in the use of this technique in settings where analysis of stable isotope ratios in biological samples is to be made by isotope ratio mass spectrometry. The publication is targeted at new users of this technique, for example nutritionists, analytical chemists and other professionals. More detailed information on the theoretical background and the practical applications of state of the art methodologies to monitor changes in body composition can be found in IAEA Human Health Series No. 3, Assessment of Body Composition and Total Energy Expenditure in Humans by Stable Isotope Techniques

  8. Protocolo de avaliação da amusia: exemplo português Evaluation protocol for amusia: portuguese sample

    Directory of Open Access Journals (Sweden)

    Maria Conceição Peixoto

    2012-12-01

    Full Text Available A amusia é uma disfunção que compromete o processamento musical. Parte desse processamento é feito a nível do cortéx auditivo primário. O estudo dessa afecção permite-nos avaliar também as vias auditivas centrais. OBJETIVO: Explorar os testes de avaliação diagnóstica da amusia. MÉTODO: Os autores propõem um protocolo de avaliação para doentes com suspeita de amusia (após lesão cerebral ou por queixas de má percepção musical, paralelamente com a avaliação do processamento auditivo central, já implementada no serviço. A base dos testes de avaliação assenta na Montreal Battery of Evaluation of Amusia. Desta ampla bateria de testes, foram selecionados alguns dos exemplos musicais para avaliação de diferentes vertentes da área musical, nomeadamente memória e percepção musical, capacidade de reconhecimento e discriminação musical. Em termos de memória, foi criado um teste de avaliação da memória tardia, adaptado à cultura portuguesa. Estudo prospectivo. RESULTADOS e CONCLUSÕES: Embora ainda em fase experimental e com possibilidades de ajustes na avaliação realizada, considera-se que esta avaliação, aliada ao estudo do processamento auditivo central, permitirá compreender algumas lesões e disfunções centrais, congênitas ou adquiridas, que limitam a percepção auditiva.Amusia is a disorder that affects the processing of music. Part of this processing happens in the primary auditory cortex. The study of this condition allows us to evaluate the central auditory pathways. OBJECTIVE: To explore the diagnostic evaluation tests of amusia. METHOD: The authors propose an evaluation protocol for patients with suspected amusia (after brain injury or complaints of poor musical perception, in parallel with the assessment of central auditory processing, already implemented in the department. The Montreal Evaluation of Battery of amusia was the basis for the selection of the tests. From this comprehensive battery of

  9. Seasonal comparison of moss bag technique against vertical snow samples for monitoring atmospheric pollution.

    Science.gov (United States)

    Salo, Hanna; Berisha, Anna-Kaisa; Mäkinen, Joni

    2016-03-01

    This is the first study seasonally applying Sphagnum papillosum moss bags and vertical snow samples for monitoring atmospheric pollution. Moss bags, exposed in January, were collected together with snow samples by early March 2012 near the Harjavalta Industrial Park in southwest Finland. Magnetic, chemical, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), K-means clustering, and Tomlinson pollution load index (PLI) data showed parallel spatial trends of pollution dispersal for both materials. Results strengthen previous findings that concentrate and slag handling activities were important (dust) emission sources while the impact from Cu-Ni smelter's pipe remained secondary at closer distances. Statistically significant correlations existed between the variables of snow and moss bags. As a summary, both methods work well for sampling and are efficient pollutant accumulators. Moss bags can be used also in winter conditions and they provide more homogeneous and better controlled sampling method than snow samples. Copyright © 2015. Published by Elsevier B.V.

  10. Fast neutron and gamma-ray transmission technique in mixed samples. MCNP calculations

    International Nuclear Information System (INIS)

    Perez, N.; Padron, I.

    2001-01-01

    In this paper the moisture in sand and also the sulfur content in toluene have been described by using the simultaneous fast neutron/gamma transmission technique (FNGT). Monte Carlo calculations show that it is possible to apply this technique with accelerator-based and isotopic neutron sources in the on-line analysis to perform the product quality control, specifically in the building materials industry and the petroleum one. It has been used particles from a 14MeV neutron generator and also from an Am-Be neutron source. The estimation of optimal system parameters like the efficiency, detection time, hazards and costs were performed in order to compare both neutron sources

  11. Sport Sampling Is Associated With Improved Landing Technique in Youth Athletes.

    Science.gov (United States)

    DiStefano, Lindsay J; Beltz, Eleanor M; Root, Hayley J; Martinez, Jessica C; Houghton, Andrew; Taranto, Nicole; Pearce, Katherine; McConnell, Erin; Muscat, Courtney; Boyle, Steve; Trojian, Thomas H

    Sport sampling is recommended to promote fundamental movement skill acquisition and physical activity. In contrast, sport specialization is associated with musculoskeletal injury risk, burnout, and attrition from sport. There is limited evidence to support the influence of sport sampling on neuromuscular control, which is associated with injury risk, in youth athletes. Athletes who participated in only 1 sport during the previous year would demonstrate higher Landing Error Scoring System (LESS) scores than their counterparts. Cross-sectional study. Level 3. A total of 355 youth athletes (age range, 8-14 years) completed a test session with a jump-landing task, which was evaluated using the LESS. Participants were categorized as single sport (SS) or multisport (MS) based on their self-reported sport participation in the past year. Their duration of sport sampling (low, moderate, high) was determined based on their sport participation history. Participants were dichotomized into good (LESS sampling duration (low, moderate, high). The MS group was 2.5 times (95% CI, 1.9-3.1) as likely to be categorized as having good control compared with the SS group (χ 2 (355) = 10.10, P sampling duration group were 5.8 times (95% CI, 3.1-8.5) and 5.4 times (95% CI, 4.0-6.8) as likely to be categorized as having good control compared with the moderate and low groups (χ 2 (216) = 11.20, P sampling at a young age is associated with improved neuromuscular control, which may reduce injury risk in youth athletes. Youth athletes should be encouraged to try participating in multiple sports to enhance their neuromuscular control and promote long-term physical activity.

  12. Hierarchical sampling of multiple strata: an innovative technique in exposure characterization

    International Nuclear Information System (INIS)

    Ericson, J.E.; Gonzalez, Elisabeth J.

    2003-01-01

    Sampling of multiple strata, or hierarchical sampling of various exposure sources and activity areas, has been tested and is suggested as a method to sample (or to locate) areas with a high prevalence of elevated blood lead in children. Hierarchical sampling was devised to supplement traditional soil lead sampling of a single stratum, either residential or fixed point source, using a multistep strategy. Blood lead (n=1141) and soil lead (n=378) data collected under the USEPA/UCI Tijuana Lead Project (1996-1999) were analyzed to evaluate the usefulness of sampling soil lead from background sites, schools and parks, point sources, and residences. Results revealed that industrial emissions have been a contributing factor to soil lead contamination in Tijuana. At the regional level, point source soil lead was associated with mean blood lead levels and concurrent high background, and point source soil lead levels were predictive of a high percentage of subjects with blood lead equal to or greater than 10 μg/dL (pe 10). Significant relationships were observed between mean blood lead level and fixed point source soil lead (r=0.93; P 2 =0.72 using a quadratic model) and between residential soil lead and fixed point source soil lead (r=0.90; P 2 =0.86 using a cubic model). This study suggests that point sources alone are not sufficient for predicting the relative risk of exposure to lead in the urban environment. These findings will be useful in defining regions for targeted or universal soil lead sampling by site type. Point sources have been observed to be predictive of mean blood lead at the regional level; however, this relationship alone was not sufficient to predict pe 10. It is concluded that when apparently undisturbed sites reveal high soil lead levels in addition to local point sources, dispersion of lead is widespread and will be associated with a high prevalence of elevated blood lead in children. Multiple strata sampling was shown to be useful in

  13. Mercury speciation in environmental solid samples using thermal release technique with atomic absorption detection

    Energy Technology Data Exchange (ETDEWEB)

    Shuvaeva, Olga V. [Institute of Inorganic Chemistry, Academician Lavrent' ev Prospect 3, 630090 Novosbirsk (Russian Federation)], E-mail: olga@che.nsk.su; Gustaytis, Maria A.; Anoshin, Gennadii N. [Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, Koptyug Prospect 3, 630090 Novosibirsk (Russian Federation)

    2008-07-28

    A sensitive and very simple method for determination of mercury species in solid samples has been developed involving thermal release analysis in combination with atomic absorption (AAS) detection. The method allows determination of mercury(II) chloride, methylmercury and mercury sulfide at the level of 0.70, 0.35 and 0.20 ng with a reproducibility of the results of 14, 25 and 18%, respectively. The accuracy of the developed assay has been estimated using certified reference materials and by comparison of the results with those of an independent method. The method has been applied for Hg species determination in original samples of lake sediments and plankton.

  14. UMTRA ground water sampling techniques: Comparison of the traditional and low flow methods

    International Nuclear Information System (INIS)

    1995-07-01

    This report describes the potential changes in water quality data that may occur with the conversion from MBV (multiple bore volume) to LF (low flow) sampling and provides two examples of how such a change might impact Project decisions. The existing scientific literature on LF sampling is reviewed and the new LF data from three UMTRA Uranium Mill Tailings Remedial Action Project sites are evaluated seeking answers to the questions posed above. Several possible approaches, that the UMTRA Project may take to address issues unanswered by the literature are presented and compared, and a recommendation is offered for the future direction of the LF conversion effort

  15. Biomechanical reposition techniques in anterior shoulder dislocation: a randomised multicentre clinical trial- the BRASD-trial protocol.

    Science.gov (United States)

    Baden, David N; Roetman, Martijn H; Boeije, Tom; Roodheuvel, Floris; Mullaart-Jansen, Nieke; Peeters, Suzanne; Burg, Mike D

    2017-07-20

    Glenohumeral (shoulder) dislocations are the most common large joint dislocations seen in the emergency department (ED). They cause pain, often severe, and require timely interventions to minimise discomfort and tissue damage. Commonly used reposition or relocation techniques often involve traction and/or leverage. These techniques have high success rates but may be painful and time consuming. They may also cause complications. Recently, other techniques-the biomechanical reposition techniques (BRTs)-have become more popular since they may cause less pain, require less time and cause fewer complications. To our knowledge, no research exists comparing the various BRTs. Our objective is to establish which BRT or BRT combination is fastest, least painful and associated with the lowest complication rate for adult ED patients with anterior glenohumeral dislocations (AGDs). Adults presenting to the participating EDs with isolated AGDs, as determined by radiographs, will be randomised to one of three BRTs: Cunningham, modified Milch or scapular manipulation. Main study parameters/endpoints are ED length of stay and patients' self-report of pain. Secondary study parameters/endpoints are procedure times, need for analgesic and/or sedative medications, iatrogenic complications and rates of successful reduction. Non-biomechanical AGD repositioning techniques based on traction and/or leverage are inherently painful and potentially harmful. We believe that the three BRTs used in this study are more physiological, more patient friendly, less likely to cause pain, more time efficient and less likely to produce complications. By comparing these three techniques, we hope to improve the care provided to adults with acute AGDs by reducing their ED length of stay and minimising pain and procedure-related complications. We also hope to define which of the three BRTs is quickest, most likely to be successful and least likely to require sedative or analgesic medications to achieve

  16. Evaluation of enzyme immunoassay techniques for diagnosis of the most common intestinal protozoa in fecal samples.

    Science.gov (United States)

    Gaafar, Maha R

    2011-08-01

    This study was designed to evaluate the antigen capture enzyme immunoassays (EIAs) Triage parasite panel and TechLab Entamoeba histolytica II in detecting Giardia intestinalis, Cryptosporidium sp, and Entamoeba histolytica in fecal samples in comparison to microscopy, and in differentiating Entamoeba histolytica from Entamoeba dispar. The Triage EIA was evaluated using 100 stool specimens that were tested by standard ova and parasite examination, including staining with both trichrome and modified acid-fast stains. Differentiation between E. histolytica and E. dispar was performed using TechLab. Microscopic examination revealed that 19% of the samples were positive for Giardia, 4% for Cryptosporidium, and 1% for E. histolytica/E. dispar, and other parasites were found in 5%. By Triage, 23% of the samples were infected with Giardia, 5% with Cryptosporidium, and 2% with E. histolytica/E. dispar. Triage showed a sensitivity of 100% and specificity of 91.5%. The TechLab assay was negative for both samples diagnosed as E. histolytica/E. dispar by Triage, which suggested that they were E. dispar. Both tests showed no cross-reactivity with other intestinal protozoa. These results indicate that antigen detection by EIA has the potential to become a valuable tool, capable of making stool diagnostics more effective. Copyright © 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  17. Soil and Water – What is Detectable through Microbiological Sample Preparation Techniques

    Science.gov (United States)

    The concerns of a potential terrorist’s use of biological agents in soil and ground water are articulated by comparisons to major illnesses in this Country involving contaminated drinking water sources. Objectives are focused on the importance of sample preparation in the rapid, ...

  18. Recent trends in sorption-based sample preparation and liquid chromatography techniques for food analysis.

    Science.gov (United States)

    V Soares Maciel, Edvaldo; de Toffoli, Ana Lúcia; Lanças, Fernando Mauro

    2018-04-20

    The accelerated rising of the world's population increased the consumption of food, thus demanding more rigors in the control of residue and contaminants in food-based products marketed for human consumption. In view of the complexity of most food matrices, including fruits, vegetables, different types of meat, beverages, among others, a sample preparation step is important to provide more reliable results when combined with HPLC separations. An adequate sample preparation step before the chromatographic analysis is mandatory in obtaining higher precision and accuracy in order to improve the extraction of the target analytes, one of the priorities in analytical chemistry. The recent discovery of new materials such as ionic liquids, graphene-derived materials, molecularly imprinted polymers, restricted access media, magnetic nanoparticles, and carbonaceous nanomaterials, provided high sensitivity and selectivity results in an extensive variety of applications. These materials, as well as their several possible combinations, have been demonstrated to be highly appropriate for the extraction of different analytes in complex samples such as food products. The main characteristics and application of these new materials in food analysis will be presented and discussed in this paper. Another topic discussed in this review covers the main advantages and limitations of sample preparation microtechniques, as well as their off-line and on-line combination with HPLC for food analysis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Stir Bar Sorptive Extraction (SBSE), a novel extraction technique for aqueous samples: theory and principles

    NARCIS (Netherlands)

    Baltussen, H.A.; Sandra, P.J.F.; David, F.; Cramers, C.A.M.G.

    1999-01-01

    The theory and practice of a novel approach for sample enrichment, namely the application of stir bars coated with the sorbent polydimethylsiloxane (PDMS) and referred to as stir bar sorptive extraction (SBSE) are presented. Stir bars with a length of 10 and 40 mm coated with 55 and 219 L of PDMS

  20. Alternative sample-introduction technique to avoid breakthrough in gradient-elution liquid chromatography of polymers

    NARCIS (Netherlands)

    Reingruber, E.; Bedani, F.; Buchberger, W.; Schoenmakers, P.

    2010-01-01

    Gradient-elution liquid chromatography (GELC) is a powerful tool for the characterization of synthetic polymers. However, gradient-elution chromatograms often suffer from breakthrough phenomena. Breakthrough can be averted by using a sample solvent as weak as the mobile phase. However, this approach

  1. Methods and Techniques of Sampling, Culturing and Identifying of Subsurface Bacteria

    International Nuclear Information System (INIS)

    Lee, Seung Yeop; Baik, Min Hoon

    2010-11-01

    This report described sampling, culturing and identifying of KURT underground bacteria, which existed as iron-, manganese-, and sulfate-reducing bacteria. The methods of culturing and media preparation were different by bacteria species affecting bacteria growth-rates. It will be possible for the cultured bacteria to be used for various applied experiments and researches in the future

  2. Environmental gamma-ray measurements using in situ and core sampling techniques

    International Nuclear Information System (INIS)

    Dickson, H.W.; Kerr, G.D.; Perdue, P.T.; Abdullah, S.A.

    1976-01-01

    Dose rates from natural radionuclides and 137 Cs in soils of the Oak Ridge area have been determined from in situ and core sample measurements. In situ γ-ray measurements were made with a transportable spectrometer. A tape of spectral data and a soil core sample from each site were returned to ORNL for further analysis. Information on soil composition, density and moisture content and on the distribution of cesium in the soil was obtained from the core samples. In situ spectra were analyzed by a computer program which identified and assigned energies to peaks, integrated the areas under the peaks, and calculated radionuclide concentrations based on a uniform distribution in the soil. The assumption of a uniform distribution was adequate only for natural radionuclides, but simple corrections can be made to the computer calculations for man-made radionuclides distributed on the surface or exponentially in the soil. For 137 Cs a correction was used based on an exponential function fitted to the distribution measured in core samples. At typical sites in Oak Ridge, the dose rate determined from these measurements was about 5 μrad/hr. (author)

  3. Use of X-ray diffraction technique and chemometrics to aid soil sampling strategies in traceability studies.

    Science.gov (United States)

    Bertacchini, Lucia; Durante, Caterina; Marchetti, Andrea; Sighinolfi, Simona; Silvestri, Michele; Cocchi, Marina

    2012-08-30

    Aim of this work is to assess the potentialities of the X-ray powder diffraction technique as fingerprinting technique, i.e. as a preliminary tool to assess soil samples variability, in terms of geochemical features, in the context of food geographical traceability. A correct approach to sampling procedure is always a critical issue in scientific investigation. In particular, in food geographical traceability studies, where the cause-effect relations between the soil of origin and the final foodstuff is sought, a representative sampling of the territory under investigation is certainly an imperative. This research concerns a pilot study to investigate the field homogeneity with respect to both field extension and sampling depth, taking also into account the seasonal variability. Four Lambrusco production sites of the Modena district were considered. The X-Ray diffraction spectra, collected on the powder of each soil sample, were treated as fingerprint profiles to be deciphered by multivariate and multi-way data analysis, namely PCA and PARAFAC. The differentiation pattern observed in soil samples, as obtained by this fast and non-destructive analytical approach, well matches with the results obtained by characterization with other costly analytical techniques, such as ICP/MS, GFAAS, FAAS, etc. Thus, the proposed approach furnishes a rational basis to reduce the number of soil samples to be collected for further analytical characterization, i.e. metals content, isotopic ratio of radiogenic element, etc., while maintaining an exhaustive description of the investigated production areas. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Correlations Between Life-Detection Techniques and Implications for Sampling Site Selection in Planetary Analog Missions

    Science.gov (United States)

    Gentry, Diana M.; Amador, Elena S.; Cable, Morgan L.; Chaudry, Nosheen; Cullen, Thomas; Jacobsen, Malene B.; Murukesan, Gayathri; Schwieterman, Edward W.; Stevens, Adam H.; Stockton, Amanda; Tan, George; Yin, Chang; Cullen, David C.; Geppert, Wolf

    2017-10-01

    We conducted an analog sampling expedition under simulated mission constraints to areas dominated by basaltic tephra of the Eldfell and Fimmvörðuháls lava fields (Iceland). Sites were selected to be "homogeneous" at a coarse remote sensing resolution (10-100 m) in apparent color, morphology, moisture, and grain size, with best-effort realism in numbers of locations and replicates. Three different biomarker assays (counting of nucleic-acid-stained cells via fluorescent microscopy, a luciferin/luciferase assay for adenosine triphosphate, and quantitative polymerase chain reaction (qPCR) to detect DNA associated with bacteria, archaea, and fungi) were characterized at four nested spatial scales (1 m, 10 m, 100 m, and >1 km) by using five common metrics for sample site representativeness (sample mean variance, group F tests, pairwise t tests, and the distribution-free rank sum H and u tests). Correlations between all assays were characterized with Spearman's rank test. The bioluminescence assay showed the most variance across the sites, followed by qPCR for bacterial and archaeal DNA; these results could not be considered representative at the finest resolution tested (1 m). Cell concentration and fungal DNA also had significant local variation, but they were homogeneous over scales of >1 km. These results show that the selection of life detection assays and the number, distribution, and location of sampling sites in a low biomass environment with limited a priori characterization can yield both contrasting and complementary results, and that their interdependence must be given due consideration to maximize science return in future biomarker sampling expeditions.

  5. Development of spatial scaling technique of forest health sample point information

    Science.gov (United States)

    Lee, J.; Ryu, J.; Choi, Y. Y.; Chung, H. I.; Kim, S. H.; Jeon, S. W.

    2017-12-01

    Most forest health assessments are limited to monitoring sampling sites. The monitoring of forest health in Britain in Britain was carried out mainly on five species (Norway spruce, Sitka spruce, Scots pine, Oak, Beech) Database construction using Oracle database program with density The Forest Health Assessment in GreatBay in the United States was conducted to identify the characteristics of the ecosystem populations of each area based on the evaluation of forest health by tree species, diameter at breast height, water pipe and density in summer and fall of 200. In the case of Korea, in the first evaluation report on forest health vitality, 1000 sample points were placed in the forests using a systematic method of arranging forests at 4Km × 4Km at regular intervals based on an sample point, and 29 items in four categories such as tree health, vegetation, soil, and atmosphere. As mentioned above, existing researches have been done through the monitoring of the survey sample points, and it is difficult to collect information to support customized policies for the regional survey sites. In the case of special forests such as urban forests and major forests, policy and management appropriate to the forest characteristics are needed. Therefore, it is necessary to expand the survey headquarters for diagnosis and evaluation of customized forest health. For this reason, we have constructed a method of spatial scale through the spatial interpolation according to the characteristics of each index of the main sample point table of 29 index in the four points of diagnosis and evaluation report of the first forest health vitality report, PCA statistical analysis and correlative analysis are conducted to construct the indicators with significance, and then weights are selected for each index, and evaluation of forest health is conducted through statistical grading.

  6. The application of statistical and/or non-statistical sampling techniques by internal audit functions in the South African banking industry

    Directory of Open Access Journals (Sweden)

    D.P. van der Nest

    2015-03-01

    Full Text Available This article explores the use by internal audit functions of audit sampling techniques in order to test the effectiveness of controls in the banking sector. The article focuses specifically on the use of statistical and/or non-statistical sampling techniques by internal auditors. The focus of the research for this article was internal audit functions in the banking sector of South Africa. The results discussed in the article indicate that audit sampling is still used frequently as an audit evidence-gathering technique. Non-statistical sampling techniques are used more frequently than statistical sampling techniques for the evaluation of the sample. In addition, both techniques are regarded as important for the determination of the sample size and the selection of the sample items

  7. Composition of atmospheric precipitation. I. Sampling technique. Use of ion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Egner, H; Eriksson, E; Emanuelsson, A

    1947-01-01

    In order to investigate the composition of atmospheric precipitations in Sweden, a technique using ion exchange resins has been developed. The possibilities of nitrate reduction, and ammonia losses, when the precipitation is collected in zinc gauges is stressed. Glass funnels are used, and they are effectively protected from bird droppings. The ion exchange resins so far available are quite serviceable but show some deficiencies as to stability, and activity in alkaline solutions. New resins, which are not yet available, seem to offer definite advantages.

  8. Elemental analysis and plant samples at el-Manzala lake by neutron activation analysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Eissa, E A; Rofail, N B; Abdel-Haleem, A S; El-Abbady, W H; Hassan, A M [Arab Republic of Egypt, Atomic energy Authority, Reactor and Neutron Physiscs Department, Cairo (Egypt)

    1996-12-31

    A soil and a plant samples were taken from two locations, Bahr el-Bakar and Bahr Kados at the Manzala lake, where a high pollution is expected. The samples were especially treated and prepared for investigation by thermal neutron activation analysis (NAA). The irradiation facilities of the first egyptian research reactor (ET-R R-1) and the hyper pure germanium (HPGe) detection system were used for such a type of analysis. Among the 34 identified elements Fe, Co, As, Ru, Cd, Te, La, Sm, Eu, Tb, Hg, Th, and U are of a special significance because of their toxic deleterious impact to organisms. This work is a part of a research project concerning pollution studies on the river nile and some lakes of egypt. The data obtained in the present work stand as a reference basic record for any future follow up of the contamination level. 1 tab.

  9. Elemental analysis and plant samples at el-Manzala lake by neutron activation analysis technique

    International Nuclear Information System (INIS)

    Eissa, E.A.; Rofail, N.B.; Abdel-Haleem, A.S.; El-Abbady, W.H.; Hassan, A.M.

    1995-01-01

    A soil and a plant samples were taken from two locations, Bahr el-Bakar and Bahr Kados at the Manzala lake, where a high pollution is expected. The samples were especially treated and prepared for investigation by thermal neutron activation analysis (NAA). The irradiation facilities of the first egyptian research reactor (ET-R R-1) and the hyper pure germanium (HPGe) detection system were used for such a type of analysis. Among the 34 identified elements Fe, Co, As, Ru, Cd, Te, La, Sm, Eu, Tb, Hg, Th, and U are of a special significance because of their toxic deleterious impact to organisms. This work is a part of a research project concerning pollution studies on the river nile and some lakes of egypt. The data obtained in the present work stand as a reference basic record for any future follow up of the contamination level. 1 tab

  10. The Application of Adaptive Sampling and Analysis Program (ASAP) Techniques to NORM Sites; FINAL

    International Nuclear Information System (INIS)

    Johnson, Robert; Smith, Karen P.; Quinn, John

    1999-01-01

    The results from the Michigan demonstration establish that this type of approach can be very effective for NORM sites. The advantages include (1) greatly reduced per sample analytical costs; (2) a reduced reliance on soil sampling and ex situ gamma spectroscopy analyses; (3) the ability to combine characterization with remediation activities in one fieldwork cycle; (4) improved documentation; and (5) ultimately better remediation, as measured by greater precision in delineating soils that are not in compliance with requirements from soils that are in compliance. In addition, the demonstration showed that the use of real-time technologies, such as the RadInSoil, can facilitate the implementation of a Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM)-based final status survey program

  11. Determination of alpha activity produced by Indian tea samples using solid state nuclear track detection technique

    International Nuclear Information System (INIS)

    Azam, Ameer; Naqvi, A.H.; Srivastava, D.S.

    2001-01-01

    India has first place in the world in the production, consumption and export of tea. The average production of tea in India is about 780 million kg annually. Indian population uses tea as a favourite beverage specially with the breakfast. Tea leaves are perennial plants and they have extension root system spread over deeper layers in the soil. Soil contains uranium as trace element. Hence, uranium is transferred to the leaves as a result of uptake from the soil over the years. Since many of the decay products of uranium are alpha emitters hence tea is a source of alpha radioactivity and can cause damaging effects. Therefore, data on alpha activity of tea samples will be useful in estimating these harmful effects at least qualitatively. In the present study the alpha activity produced by thirteen samples of tea available in the local market was measured

  12. Comparison of soil solution sampling techniques to assess metal fluxes from contaminated soil to groundwater.

    Science.gov (United States)

    Coutelot, F; Sappin-Didier, V; Keller, C; Atteia, O

    2014-12-01

    The unsaturated zone plays a major role in elemental fluxes in terrestrial ecosystems. A representative chemical analysis of soil pore water is required for the interpretation of soil chemical phenomena and particularly to assess Trace Elements (TEs) mobility. This requires an optimal sampling system to avoid modification of the extracted soil water chemistry and allow for an accurate estimation of solute fluxes. In this paper, the chemical composition of soil solutions sampled by Rhizon® samplers connected to a standard syringe was compared to two other types of suction probes (Rhizon® + vacuum tube and Rhizon® + diverted flow system). We investigated the effects of different vacuum application procedures on concentrations of spiked elements (Cr, As, Zn) mixed as powder into the first 20 cm of 100-cm columns and non-spiked elements (Ca, Na, Mg) concentrations in two types of columns (SiO2 sand and a mixture of kaolinite + SiO2 sand substrates). Rhizon® was installed at different depths. The metals concentrations showed that (i) in sand, peak concentrations cannot be correctly sampled, thus the flux cannot be estimated, and the errors can easily reach a factor 2; (ii) in sand + clay columns, peak concentrations were larger, indicating that they could be sampled but, due to sorption on clay, it was not possible to compare fluxes at different depths. The different samplers tested were not able to reflect the elemental flux to groundwater and, although the Rhizon® + syringe device was more accurate, the best solution remains to be the use of a lysimeter, whose bottom is kept continuously at a suction close to the one existing in the soil.

  13. use of nuclear spectroscopic techniques for assessment of polluting elements in environmental samples

    International Nuclear Information System (INIS)

    El Reefy, H.I.

    2011-01-01

    The concentrations of elements and radioisotopes in sediment, soil, water and wild plant samples collected from Burullus Lake, Egypt, has been studied in order to understand current contamination due to agricultural and industrial wastewaters. A multiple approaches were applied to assess properly sediment contamination in the Burullus Lake. The distributions of the Al, Fe and Mn in the lake's sediments are relatively homogenous with the exception of three locations with significantly high levels of Al and Fe in close approximation in the southeastern part. Sediments collected from the lake can be categorized as unpolluted with the exception of three locations which were very low polluted with Sr based on the geo-accumulation indices. High enrichment factors were obtained for Mn, Co, Cr, Cu and Zn. The MPIs indicate that one of the drain may have a major role in mobilizing major and trace metals in the lake environment while cluster analysis indicates possible pollution from only three of the drainage channels. Comparisons with consensus-based sediment quality guidelines revealed that 100%, ∼69%, ∼92% and ∼∼15% of the samples exceeded the threshold effect concentration for Cr, Cu, Ni and Zn, respectively, with over 15% for Cr and Ni of the sample concentrations falling above the probable effect concentration. On the other hand, no samples exceed both levels for Pb. The concentration of 40 K is uniform and that of 137 Cs is generally higher in eastern part of the lake. The result indicate that 226 Ra is less soluble in the lake environment than 232 Th. Elemental concentrations in water have uniform distributions and the Fe, Mn, Co, Cr, Cu and Ni are more likely to exist in soluble phase in the lake environment.

  14. Determination of uranium in urine samples for workers in the phosphoric acid purification using fluorimetry technique

    International Nuclear Information System (INIS)

    Kharita, M. H.; Sakhita, Kh.; Aldalal, Z.

    2003-10-01

    There is probability of exposure to uranium for workers in the phosphoric acid purification (internal exposure) by inhalation, and the deposition of this uranium in organs and tissues, and the consequence excreation out of the body by perspiration or urine. This study focuses on the determination of uranium in urine samples of workers. All results seem to be under the detection limit of the method, therefore no routine monitoring is required. (author)

  15. Application of Compton suppression spectrometry in the improvement of nuclear analytical techniques for biological samples

    International Nuclear Information System (INIS)

    Ahmed, Y. A.; Ewa, I.O.B.; Funtua, I.I.; Jonah, S.A.; Landsberger, S.

    2007-01-01

    Compton Suppression Factors (SF) and Compton Reduction Factors (RF) of the UT Austin's Compton suppression spectrometer being parameters characterizing the system performance were measured using ''1''3''7Cs and ''6''0Co point sources. The system performance was evaluated as a function of energy and geometry. The (P/C), A(P/C), (P/T), Cp, and Ce were obtained for each of the parameters. The natural background reduction factor in the anticoincidence mode and that of normal mode was calculated and its effect on the detection limit of biological samples evaluated. Applicability of the spectrometer and the method for biological samples was tested in the measurement of twenty-four elements (Ba, Sr, I, Br, Cu, V, Mg, Na, Cl, Mn, Ca, Sn, In, K, Mo, Cd, Zn, As, Sb, Ni, Rb, Cs, Fe, and Co) commonly found in food, milk, tea and tobacco items. They were determined from seven National Institute for Standard and Technology (NIST) certified reference materials (rice flour, oyster tissue, non-fat powdered milk, peach leaves, tomato leaves, apple leaves, and citrus leaves). Our results shows good agreement with the NIST certified values, indicating that the method developed in the present study is suitable for the determination of aforementioned elements in biological samples without undue interference problems

  16. [Transabdominal chorionic villus sampling using biopsy forceps or needle: pregnancy outcomes by technique used].

    Science.gov (United States)

    Spallina, J; Anselem, O; Haddad, B; Touboul, C; Tsatsaris, V; Le Ray, C

    2014-11-01

    To compare pregnancy outcomes after transabdominal chorionic villus sampling using biopsy forceps or needle. Retrospective bicentric study including all women who had a transabdominal chorionic villus sampling between 2005 and 2009 (172 using biopsy forceps and 160 using needle). The primary endpoint was the rate of fetal loss, after excluding medical abortion due to the result of the biopsy. The secondary endpoint was the rate of premature rupture of the membrane. All cases were reviewed to try to determine the responsibility of the biopsy. The pregnancy outcomes were not different between the two groups: 4 (4.4%) fetal losses in the biopsy forceps group and 6 (7.4%) in the needle group (P=0.52). Only one case (1.2%) of fetal loss can be attributed to the biopsy, using a needle, and none (0%) following a forceps biospy (P=0.29). The rate of premature rupture of the membrane was comparable in the two groups. The pregnancy outcomes following chorionic villus sampling using a biopsy forceps or a needle seem comparable. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  17. Spatial distribution of metals in soil samples from Zona da Mata, Pernambuco, Brazil using XRF technique

    International Nuclear Information System (INIS)

    Fernandez, Zahily Herrero; Santos Junior, Jose Araujo dos; Amaral, Romilton dos Santos; Menezes, Romulo Simoes Cezar; Santos, Josineide Marques do Nascimento; Bezerra, Jairo Dias; Damascena, Kennedy Francys Rodrigues; Silva, Edvane Borges da; Silva, Alberto Antonio da

    2015-01-01

    Soil contamination is today one of the most important environmental issues for society. In the past, soil pollution was not considered as important as air and water contamination, because this was more difficult to be controlled, becoming an important topic in studies of environmental protection worldwide. Based on this, this paper provides information on the determination of metals in soil samples collected in Zona da Mata, Pernambuco, Brazil, where normally the application of pesticides, insecticides and other agricultural additives are used in a disorderly manner and without control. A total of 24 sampling points were monitored. The analysis of Mn, Fe, Ni, Zn, Br, Rb, Sr, Pb, Ti, La, Al, Si and P were performed using Energy Dispersive X-Ray Fluorescence. In order to assess the development of analytical method, inorganic Certified Reference Materials (IAEA-SOIL-7 and SRM 2709) were analyzed. In each sampling site, the geoaccumulation index were calculated to estimate the level of metal contamination in the soil, this was made taking into account the resolution 460 of the National Environmental Council (CONAMA in Portuguese). The elemental distribution patterns obtained for each metal were associated with different pollution sources. This assessment provides an initial description of pollution levels presented by metals in soils from several areas of Zona da Mata, providing quantitative evidence and demonstrating the need to improve the regulation of agricultural and industrial activities. (author)

  18. Spatial distribution of metals in soil samples from Zona da Mata, Pernambuco, Brazil using XRF technique

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Zahily Herrero; Santos Junior, Jose Araujo dos; Amaral, Romilton dos Santos; Menezes, Romulo Simoes Cezar; Santos, Josineide Marques do Nascimento; Bezerra, Jairo Dias; Damascena, Kennedy Francys Rodrigues, E-mail: zahily1985@gmail.com, E-mail: jaraujo@ufpe.br, E-mail: romilton@ufpe.br, E-mail: rmenezes@ufpe.br, E-mail: neideden@hotmail.com, E-mail: jairo.dias@ufpe.br, E-mail: kennedy.eng.ambiental@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Centro de Tecnologia e Geociencias. Departamento de Energia Nuclear; Alvarez, Juan Reinaldo Estevez, E-mail: jestevez@ceaden.cu [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Havana (Cuba); Silva, Edvane Borges da, E-mail: edvane.borges@pq.cnpq.br [Universidade Federal de Pernambuco (UFPE), Vitoria de Santo Antao, PE (Brazil). Nucleo de Biologia; Franca, Elvis Joacir de; Farias, Emerson Emiliano Gualberto de, E-mail: ejfranca@cnen.gov.br, E-mail: emersonemiliano@yahoo.com.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Silva, Alberto Antonio da, E-mail: alberto.silva@barreiros.ifpe.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Barreiros, PE (Brazil)

    2015-07-01

    Soil contamination is today one of the most important environmental issues for society. In the past, soil pollution was not considered as important as air and water contamination, because this was more difficult to be controlled, becoming an important topic in studies of environmental protection worldwide. Based on this, this paper provides information on the determination of metals in soil samples collected in Zona da Mata, Pernambuco, Brazil, where normally the application of pesticides, insecticides and other agricultural additives are used in a disorderly manner and without control. A total of 24 sampling points were monitored. The analysis of Mn, Fe, Ni, Zn, Br, Rb, Sr, Pb, Ti, La, Al, Si and P were performed using Energy Dispersive X-Ray Fluorescence. In order to assess the development of analytical method, inorganic Certified Reference Materials (IAEA-SOIL-7 and SRM 2709) were analyzed. In each sampling site, the geoaccumulation index were calculated to estimate the level of metal contamination in the soil, this was made taking into account the resolution 460 of the National Environmental Council (CONAMA in Portuguese). The elemental distribution patterns obtained for each metal were associated with different pollution sources. This assessment provides an initial description of pollution levels presented by metals in soils from several areas of Zona da Mata, providing quantitative evidence and demonstrating the need to improve the regulation of agricultural and industrial activities. (author)

  19. Variable sampling-time technique for improving count rate performance of scintillation detectors

    International Nuclear Information System (INIS)

    Tanaka, E.; Nohara, N.; Murayama, H.

    1979-01-01

    A new technique is presented to improve the count rate capability of a scintillation spectrometer or a position sensitive detector with minimum loss of resolution. The technique is based on the combination of pulse shortening and selective integration in which the integration period is not fixed but shortened by the arrival of the following pulse. Theoretical analysis of the degradation of the statiscal component of resolution is made for the proposed system with delay line pulse shortening, and the factor of resolution loss is formulated as a function of the input pulse rate. A new method is also presented for determining the statistical component of resolution separately from the non-statistical system resolution. Preliminary experiments with a NaI(Tl) detector have been carried out, the results of which are consistent with the theoretical prediction. However, due to the non-exponential scintillation decay of the NaI(Tl) crystal, a simple delay line clipping is not satisfactory, and an RC high-pass filter has been added, which results in further degradation of the statistical resolution. (Auth.)

  20. A cost-saving statistically based screening technique for focused sampling of a lead-contaminated site

    International Nuclear Information System (INIS)

    Moscati, A.F. Jr.; Hediger, E.M.; Rupp, M.J.

    1986-01-01

    High concentrations of lead in soils along an abandoned railroad line prompted a remedial investigation to characterize the extent of contamination across a 7-acre site. Contamination was thought to be spotty across the site reflecting its past use in battery recycling operations at discrete locations. A screening technique was employed to delineate the more highly contaminated areas by testing a statistically determined minimum number of random samples from each of seven discrete site areas. The approach not only quickly identified those site areas which would require more extensive grid sampling, but also provided a statistically defensible basis for excluding other site areas from further consideration, thus saving the cost of additional sample collection and analysis. The reduction in the number of samples collected in ''clean'' areas of the site ranged from 45 to 60%

  1. Use of an oscillation technique to measure effective cross-sections of fissionable samples in critical assemblies

    International Nuclear Information System (INIS)

    Tretiakoff, O.; Vidal, R.; Carre, J.C.; Robin, M.

    1964-01-01

    The authors describe the technique used to measure the effective absorption and neutron-yield cross-sections of a fissionable sample. These two values are determined by analysing the signals due to the variation in reactivity (over-all signal) and the local perturbation in the flux (local signal) produced by the oscillating sample. These signals are standardized by means of a set of samples containing quantities of fissionable material ( 235 U) and an absorber, boron, which are well known. The measurements are made for different neutron spectra characterized by lattice parameters which constitute the central zone within which the sample moves. This technique is used to study the effective cross-sections of uranium-plutonium alloys for different heavy-water and graphite lattices in the MINERVE and MARIUS critical assemblies. The same experiments are carried out on fuel samples of different irradiations in order to determine the evolution of effective cross-sections as a function of the spectrum and the irradiations. (authors) [fr

  2. Reverse sample genome probing, a new technique for identification of bacteria in environmental samples by DNA hybridization, and its application to the identification of sulfate-reducing bacteria in oil field samples

    International Nuclear Information System (INIS)

    Voordouw, G.; Voordouw, J.K.; Karkhoff-Schweizer, R.R.; Fedorak, P.M.; Westlake, D.W.S.

    1991-01-01

    A novel method for identification of bacteria in environmental samples by DNA hybridization is presented. It is based on the fact that, even within a genus, the genomes of different bacteria may have little overall sequence homology. This allows the use of the labeled genomic DNA of a given bacterium (referred to as a standard) to probe for its presence and that of bacteria with highly homologous genomes in total DNA obtained from an environmental sample. Alternatively, total DNA extracted from the sample can be labeled and used to probe filters on which denatured chromosomal DNA from relevant bacterial standards has been spotted. The latter technique is referred to as reverse sample genome probing, since it is the reverse of the usual practice of deriving probes from reference bacteria for analyzing a DNA sample. Reverse sample genome probing allows identification of bacteria in a sample in a single step once a master filter with suitable standards has been developed. Application of reverse sample genome probing to the identification of sulfate-reducing bacteria in 31 samples obtained primarily from oil fields in the province of Alberta has indicated that there are at least 20 genotypically different sulfate-reducing bacteria in these samples

  3. Study of uranium mineralization in rock samples from marwat range bannu basin by fission track analysis technique

    International Nuclear Information System (INIS)

    Qureshi, A.Z.; Ullah, K.; Ullah, N.; Akram, M.

    2004-07-01

    The Geophysics Division, Atomic Energy Minerals Centre (AEMC), Lahore has planned a uranium exploration program in Marwat Range, Bannu Basin. In this connection 30 thin sections of rock samples, collected from four areas; namely, Darra Tang, Simukili, Karkanwal and Sheikhillah from Marwat Range, and one from Salt Range were provided to Nuclear Geology Group of Physics Research Division, PINSTECH for the study of nature and mechanism of uranium mineralization These studies are aimed to help in designing uranium exploration strategy by providing the loci of uranium sources in the Marwat and Salt Ranges. The samples have been studied using fission track analysis technique. (author)

  4. Facile and Sensitive Spectrophotometric Technique for the Determination of Carbofuran in its Formulations, Water and Grain Samples with Substituted Anilines

    Directory of Open Access Journals (Sweden)

    V. Harikishna

    2005-01-01

    Full Text Available Methods are described for the determination of carbofuran in its formulations, in water and grain samples by the diazotization coupling spectrophotometric technique, using substituted anilines such as 4-bromoaniline, 4-methylaniline and 4-aminobenzaldehyde as the coupling agents. The orange red colour formed with 4-bromoaniline shows maximum absorption at 478 nm, yellow colour obtained with 4-methylaniline have maximum absorption at 465 nm whereas a red colour derivative formed with 4-aminobenzaldehyde shows λmax at 472 nm. The methods could be successfully applied for the determination of carbofuran in its formulations, water and grain samples.

  5. Separation and sampling technique of light element isotopes by chemical exchange process

    International Nuclear Information System (INIS)

    Kato, Shunsaku; Oi, Kenta; Takagi, Norio; Hirotsu, Takafumi; Kano, Hirofumi; Sonoda, Akinari; Makita, Yoji

    2000-01-01

    Lithium and boron isotope separation technique were studied. Granulation of lithium isotope separation agent was carried out by cure covering in solution. Separation of lithium isotope was stepped up by ammonium carbonate used as elusion agent. Styrene and ester resin derived three kinds of agents such as 2-amino-1, 3-propanediol (1, 3-PD), 2-amino-2-methyl-1, 3-propanediol (Me-1,3-PD) and tris(2-hydroxyethyl)amine (Tris) were used as absorbent.The ester resin with Tris showed larger amount of adsorption (1.4 mmol/g) than other resins. However, all resins with agent indicated more large adsorption volume of boron than the objective value (0.5 mmol/g). Large isotope shift was shown by the unsymmetrical vibration mode of lithium ion on the basis of quantum chemical calculation of isotope effect on dehydration of hydrated lithium ion. (S.Y.)

  6. Laser Based In Situ Techniques: Novel Methods for Generating Extreme Conditions in TEM Samples

    Energy Technology Data Exchange (ETDEWEB)

    Taheri, M; Lagrange, T; Reed, B; Armstrong, M; Campbell, G; DeHope, W; Kim, J; King, W; Masiel, D; Browning, N

    2008-02-25

    The Dynamic Transmission Electron Microscope (DTEM) is introduced as a novel tool for in situ processing of materials. Examples of various types of dynamic studies outline the advantages and differences of laser-based heating in the DTEM in comparison to conventional (resistive) heating in situ TEM methods. We demonstrate various unique capabilities of the drive laser, namely, in situ processing of nanoscale materials, rapid and high temperature phase transformations, and controlled thermal activation of materials. These experiments would otherwise be impossible without the use of the DTEM drive laser. Thus, the potential of the DTEM to as a new technique to process and characterize the growth of a myriad of micro and nanostructures is demonstrated.

  7. Seasonal atmospheric deposition variations of polychlorinated biphenyls (PCBs) and comparison of some deposition sampling techniques.

    Science.gov (United States)

    Birgül, Askın; Tasdemir, Yücel

    2011-03-01

    Ambient air and bulk deposition samples were collected between June 2008 and June 2009. Eighty-three polychlorinated biphenyl (PCB) congeners were targeted in the samples. The average gas and particle PCB concentrations were found as 393 ± 278 and 70 ± 102 pg/m(3), respectively, and 85% of the atmospheric PCBs were in the gas phase. Bulk deposition samples were collected by using a sampler made of stainless steel. The average PCB bulk deposition flux value was determined as 6,020 ± 4,350 pg/m(2) day. The seasonal bulk deposition fluxes were not statistically different from each other, but the summer flux had higher values. Flux values differed depending on the precipitation levels. The average flux value in the rainy periods was 7,480 ± 4,080 pg/m(2) day while the average flux value in dry periods was 5,550 ± 4,420 pg/m(2) day. The obtained deposition values were lower than the reported values given for the urban and industrialized areas, yet close to the ones for the rural sites. The reported deposition values were also influenced by the type of the instruments used. The average dry deposition and total deposition velocity values calculated based on deposition and concentration values were found as 0.23 ± 0.21 and 0.13 ± 0.13 cm/s, respectively.

  8. The capillary adhesion technique: a versatile method for determining the liquid adhesion force and sample stiffness

    Directory of Open Access Journals (Sweden)

    Daniel Gandyra

    2015-01-01

    Full Text Available We report a novel, practical technique for the concerted, simultaneous determination of both the adhesion force of a small structure or structural unit (e.g., an individual filament, hair, micromechanical component or microsensor to a liquid and its elastic properties. The method involves the creation and development of a liquid meniscus upon touching a liquid surface with the structure, and the subsequent disruption of this liquid meniscus upon removal. The evaluation of the meniscus shape immediately before snap-off of the meniscus allows the quantitative determination of the liquid adhesion force. Concurrently, by measuring and evaluating the deformation of the structure under investigation, its elastic properties can be determined. The sensitivity of the method is remarkably high, practically limited by the resolution of the camera capturing the process. Adhesion forces down to 10 µN and spring constants up to 2 N/m were measured. Three exemplary applications of this method are demonstrated: (1 determination of the water adhesion force and the elasticity of individual hairs (trichomes of the floating fern Salvinia molesta. (2 The investigation of human head hairs both with and without functional surface coatings (a topic of high relevance in the field of hair cosmetics was performed. The method also resulted in the measurement of an elastic modulus (Young’s modulus for individual hairs of 3.0 × 105 N/cm2, which is within the typical range known for human hair. (3 Finally, the accuracy and validity of the capillary adhesion technique was proven by examining calibrated atomic force microscopy cantilevers, reproducing the spring constants calibrated using other methods.

  9. Calibrating passive sampling and passive dosing techniques to lipid based concentrations

    DEFF Research Database (Denmark)

    Mayer, Philipp; Schmidt, Stine Nørgaard; Annika, A.

    2011-01-01

    Equilibrium sampling into various formats of the silicone polydimethylsiloxane (PDMS) is increasingly used to measure the exposure of hydrophobic organic chemicals in environmental matrices, and passive dosing from silicone is increasingly used to control and maintain their exposure in laboratory...... coated vials and with Head Space Solid Phase Microextraction (HS-SPME) yielded lipid based concentrations that were in good agreement with each other, but about a factor of two higher than measured lipid-normalized concentrations in the organisms. Passive dosing was applied to bioconcentration...

  10. Gamma-ray attenuation technique for determining density and water content of wood samples

    International Nuclear Information System (INIS)

    Ferraz, E.S.B.; Aguiar, O.

    1985-01-01

    The theoretical aspects of application of the Beer-Lambert law are discussed, with emphasis on the maximum theoretical error expected. A serie of measurements of moisture content within the range of 8g/cm 3 to 30g/cm 3 are made on samples of Pinus oocarpa by gamma-ray ( 241 Am) attenuation methods and by the conventional gravimetric method. The relative deviations (experimental errors) found in the determinations made by these two methods are compared with the theoretical errors calculated, showing the viability of the gamma-ray method. (M.A.C.) [pt

  11. Use of the electrodeposition technique in the preparation of samples of 237Np and its determination by alpha spectrometry

    International Nuclear Information System (INIS)

    Mertzig, W.; Matsuda, H.T.; Araujo, B.F. de; Araujo, J.A. de.

    1981-05-01

    The electroplating technique to prepare 237 Np source and its determination by alpha spectrometry is presented. The samples were prepared using a lucite-eletrolitic cell manufactured at IPEN, specially to trace amounts of actinides. A polished brass disk coated with Ni film has been used as cathodo and a fixed Pt wire as anode. The electroplated samples were alpha counted using a surface barrier detector. The optimum conditions to obtain the quantitative deposition of 237 Np have been achieved by studying the effects of some parameters as current density, pH and concentration of eletrolitic solution and time of eletrodeposition, using a carrier technique. After preliminary purification, the method is applied to control trace amounts of 237 Np in the Purex process solutions. (Author) [pt

  12. Product-selective blot: a technique for measuring enzyme activities in large numbers of samples and in native electrophoresis gels

    International Nuclear Information System (INIS)

    Thompson, G.A.; Davies, H.M.; McDonald, N.

    1985-01-01

    A method termed product-selective blotting has been developed for screening large numbers of samples for enzyme activity. The technique is particularly well suited to detection of enzymes in native electrophoresis gels. The principle of the method was demonstrated by blotting samples from glutaminase or glutamate synthase reactions into an agarose gel embedded with ion-exchange resin under conditions favoring binding of product (glutamate) over substrates and other substances in the reaction mixture. After washes to remove these unbound substances, the product was measured using either fluorometric staining or radiometric techniques. Glutaminase activity in native electrophoresis gels was visualized by a related procedure in which substrates and products from reactions run in the electrophoresis gel were blotted directly into a resin-containing image gel. Considering the selective-binding materials available for use in the image gel, along with the possible detection systems, this method has potentially broad application

  13. Beyond simple small-angle X-ray scattering: developments in online complementary techniques and sample environments

    Directory of Open Access Journals (Sweden)

    Wim Bras

    2014-11-01

    Full Text Available Small- and wide-angle X-ray scattering (SAXS, WAXS are standard tools in materials research. The simultaneous measurement of SAXS and WAXS data in time-resolved studies has gained popularity due to the complementary information obtained. Furthermore, the combination of these data with non X-ray based techniques, via either simultaneous or independent measurements, has advanced understanding of the driving forces that lead to the structures and morphologies of materials, which in turn give rise to their properties. The simultaneous measurement of different data regimes and types, using either X-rays or neutrons, and the desire to control parameters that initiate and control structural changes have led to greater demands on sample environments. Examples of developments in technique combinations and sample environment design are discussed, together with a brief speculation about promising future developments.

  14. Beyond simple small-angle X-ray scattering: developments in online complementary techniques and sample environments.

    Science.gov (United States)

    Bras, Wim; Koizumi, Satoshi; Terrill, Nicholas J

    2014-11-01

    Small- and wide-angle X-ray scattering (SAXS, WAXS) are standard tools in materials research. The simultaneous measurement of SAXS and WAXS data in time-resolved studies has gained popularity due to the complementary information obtained. Furthermore, the combination of these data with non X-ray based techniques, via either simultaneous or independent measurements, has advanced understanding of the driving forces that lead to the structures and morphologies of materials, which in turn give rise to their properties. The simultaneous measurement of different data regimes and types, using either X-rays or neutrons, and the desire to control parameters that initiate and control structural changes have led to greater demands on sample environments. Examples of developments in technique combinations and sample environment design are discussed, together with a brief speculation about promising future developments.

  15. Sampling practices and analytical techniques used in the monitoring of steam and water in CEGB nuclear boilers

    International Nuclear Information System (INIS)

    Goodfellow, G.I.

    1978-01-01

    The steam and water in CEGB Magnox and AGR nuclear boilers are continuously monitored, using both laboratory techniques and on-line instrumentation, in order to maintain the chemical quality within pre-determined limits. The sampling systems in use and some of the difficulties associated with sampling requirements are discussed. The relative merits of chemical instruments installed either locally in various parts of the plant or in centralized instrument rooms are reviewed. The quality of water in nuclear boilers, as with all high-pressure steam-raising plant, is extremely high; consequently very sensitive analytical procedures are required, particularly for monitoring the feed-water of 'once-through boiler' systems. Considerable progress has been made in this field and examples are given of some of the techniques developed for analyses at the 'μ/kg' level together with some of the current problems.(author)

  16. The role of contrast-enhanced ultrasound (CEUS) in visualizing atherosclerotic carotid plaque vulnerability: Which injection protocol? Which scanning technique?

    Energy Technology Data Exchange (ETDEWEB)

    Iezzi, Roberto, E-mail: roberto.iezzi@rm.unicatt.it [Department of Bioimaging and Radiological Sciences, Institute of Radiology, “A. Gemelli” Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Petrone, Gianluigi [Institute of Pathology, “A. Gemelli” Hospital—Catholic University, L.go A Gemelli 8, 00168, Rome (Italy); Ferrante, Angela [Department of Vascular Surgery, “A. Gemelli” Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Lauriola, Libero [Institute of Pathology, “A. Gemelli” Hospital—Catholic University, L.go A Gemelli 8, 00168, Rome (Italy); Vincenzoni, Claudio [Department of Vascular Surgery, “A. Gemelli” Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Torre, Michele Fabio la [Department of Bioimaging and Radiological Sciences, Institute of Radiology, “A. Gemelli” Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Snider, Francesco [Department of Vascular Surgery, “A. Gemelli” Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Rindi, Guido [Institute of Pathology, “A. Gemelli” Hospital—Catholic University, L.go A Gemelli 8, 00168, Rome (Italy); Bonomo, Lorenzo [Department of Bioimaging and Radiological Sciences, Institute of Radiology, “A. Gemelli” Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy)

    2015-05-15

    Highlights: • CEUS is a safe and efficacious technique for the identification and characterization of carotid plaque. • CEUS represents a diagnostic tool for the management of patients with carotid plaque, particularly in asymptomatic patients. • Improved diagnostic performance is achieved with the injection of 4 mL bolus of contrast-medium. • Improved diagnostic performance is achieved with the use of Dynamic Imaging rather than late-phase imaging. - Abstract: Purpose: To correlate the degree of plaque vulnerability as determined by contrast-enhanced ultrasound (CEUS) with histological findings. Secondary objectives were to optimize the CEUS acquisition technique and image evaluation methods. Materials and methods: Fifty consecutive patients, either symptomatic and asymptomatic referring to our department in order to perform carotid endarterectomy (TEA), were enrolled. Each patient provided informed consent before undergoing CEUS. Ultrasound examination was performed using high-frequency (8–14 MHz) linear probe and a non-linear pulse inversion technique (mechanical index: 0.09–1.3). A double contrast media injection (Sonovue, 2 mL and 4 mL; Bracco, Italy) was performed. Two videotapes were recorded for every injection: early “dynamic” phase and late “flash” phase, performed with 6 high mechanical index impulses. Movies were quantitatively and qualitatively evaluated. Qualitative and quantitative evaluation were statistically compared to immunohistological diagnosis of vulnerable plaque, considered as gold standard. Results: Qualitative CEUS evaluation obtained high statistical results when compared to immunohistological results, with values of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of 94%, 68%, 87%, 85% and 86%, respectively, which became higher if considering only asymptomatic patient, with a NPV of 91%. Nevertheless, quantitative software evaluation proved less

  17. Amorphous and liquid samples structure and density measurements at high pressure - high temperature using diffraction and imaging techniques

    Science.gov (United States)

    Guignot, N.; King, A.; Clark, A. N.; Perrillat, J. P.; Boulard, E.; Morard, G.; Deslandes, J. P.; Itié, J. P.; Ritter, X.; Sanchez-Valle, C.

    2016-12-01

    Determination of the density and structure of liquids such as iron alloys, silicates and carbonates is a key to understand deep Earth structure and dynamics. X-ray diffraction provided by large synchrotron facilities gives excellent results as long as the signal scattered from the sample can be isolated from its environment. Different techniques already exist; we present here the implementation and the first results given by the combined angle- and energy-dispersive structural analysis and refinement (CAESAR) technique introduced by Wang et al. in 2004, that has never been used in this context. It has several advantages in the study of liquids: 1/ the standard energy-dispersive technique (EDX), fast and compatible with large multi-anvil presses frames, is used for fast analysis free of signal pollution from the sample environment 2/ some limitations of the EDX technique (homogeneity of the sample, low resolution) are irrelevant in the case of liquid signals, others (wrong intensities, escape peaks artifacts, background subtraction) are solved by the CAESAR technique 3/ high Q data (up to 15 A-1 and more) can be obtained in a few hours (usually less than 2). We present here the facilities available on the PSICHE beamline (SOLEIL synchrotron, France) and a few results obtained using a Paris-Edinburgh (PE) press and a 1200 tons load capacity multi-anvil press with a (100) DIA compression module. X-ray microtomography, used in conjunction with a PE press featuring rotating anvils (RotoPEc, Philippe et al., 2013) is also very effective, by simply measuring the 3D volume of glass or liquid spheres at HPHT, thus providing density. This can be done in conjunction with the CAESAR technique and we illustrate this point. Finally, absorption profiles can be obtained via imaging techniques, providing another independent way to measure the density of these materials. References Y. Wang et al., A new technique for angle-dispersive powder diffraction using an energy

  18. Microextraction Techniques Coupled to Liquid Chromatography with Mass Spectrometry for the Determination of Organic Micropollutants in Environmental Water Samples

    Directory of Open Access Journals (Sweden)

    Mª Esther Torres Padrón

    2014-07-01

    Full Text Available Until recently, sample preparation was carried out using traditional techniques, such as liquid–liquid extraction (LLE, that use large volumes of organic solvents. Solid-phase extraction (SPE uses much less solvent than LLE, although the volume can still be significant. These preparation methods are expensive, time-consuming and environmentally unfriendly. Recently, a great effort has been made to develop new analytical methodologies able to perform direct analyses using miniaturised equipment, thereby achieving high enrichment factors, minimising solvent consumption and reducing waste. These microextraction techniques improve the performance during sample preparation, particularly in complex water environmental samples, such as wastewaters, surface and ground waters, tap waters, sea and river waters. Liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS and time-of-flight mass spectrometric (TOF/MS techniques can be used when analysing a broad range of organic micropollutants. Before separating and detecting these compounds in environmental samples, the target analytes must be extracted and pre-concentrated to make them detectable. In this work, we review the most recent applications of microextraction preparation techniques in different water environmental matrices to determine organic micropollutants: solid-phase microextraction SPME, in-tube solid-phase microextraction (IT-SPME, stir bar sorptive extraction (SBSE and liquid-phase microextraction (LPME. Several groups of compounds are considered organic micropollutants because these are being released continuously into the environment. Many of these compounds are considered emerging contaminants. These analytes are generally compounds that are not covered by the existing regulations and are now detected more frequently in different environmental compartments. Pharmaceuticals, surfactants, personal care products and other chemicals are considered micropollutants. These

  19. Demonstration of Novel Sampling Techniques for Measurement of Turbine Engine Volatile and Non-Volatile Particulate Matter (PM) Emissions

    Science.gov (United States)

    2017-03-06

    WP-201317) Demonstration of Novel Sampling Techniques for Measurement of Turbine Engine Volatile and Non-volatile Particulate Matter (PM... Engine Volatile and Non-Volatile Particulate Matter (PM) Emissions 6. AUTHOR(S) E. Corporan, M. DeWitt, C. Klingshirn, M.D. Cheng, R. Miake-Lye, J. Peck...the performance and viability of two devices to condition aircraft turbine engine exhaust to allow the accurate measurement of total (volatile and non

  20. Separation techniques for low-level determination of actinides in soil samples

    Energy Technology Data Exchange (ETDEWEB)

    Eikenberg, J. [Paul Scherrer Institute, Department Logistics for Radiation Safety and Security, CH-5232 Villigen (Switzerland)], E-mail: jost.eikenberg@psi.ch; Jaeggi, M.; Beer, H.; Ruethi, M.; Zumsteg, I. [Paul Scherrer Institute, Department Logistics for Radiation Safety and Security, CH-5232 Villigen (Switzerland)

    2009-05-15

    The separation methods for soil samples applied at PSI are based on extraction chromatography and ion exchange. After sample leaching, the actinides are pre-concentrated via precipitation using oxalic acid. Besides the classical separation methods applying the extraction chromatographic resins U/TEVA{sup TM} (for U, Th), TRU{sup TM} (Pu, Am), new methods were recently implemented to increase the radiochemical recovery of particularly trivalent Am and Cm. These methods do not require initial reduction of Pu(IV) to Pu(III) but stabilize Pu on the tetravalent oxidation state using a mixture of NaNO{sub 2}/H{sub 2}O{sub 2} in strong acidic medium. The Pu-fraction is then fixed along with Th onto Dowex AG 1-X2 anion exchanger resin. Th is eluted via complexation with 10 M HCl, Pu via reduction with HI. The fractions of Am+Cm and U are loaded onto DGA{sup TM} resin. This resin shows extraordinary high distribution coefficients (k'-values) exceeding 10{sup 4} (for Am) in strong nitric acid medium. The separation between U and Am is obtained quantitatively by decreasing the HNO{sub 3} concentration from 3 to 0.25 M (stripping of the U-fraction) while Am can be easily eluted thereafter using 0.25 M HCl as complexation compound.

  1. A comparison of quantitative reconstruction techniques for PIXE-tomography analysis applied to biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, D.G., E-mail: dgbeasley@ctn.ist.utl.pt [IST/C2TN, Universidade de Lisboa, Campus Tecnológico e Nuclear, E.N.10, 2686-953 Sacavém (Portugal); Alves, L.C. [IST/C2TN, Universidade de Lisboa, Campus Tecnológico e Nuclear, E.N.10, 2686-953 Sacavém (Portugal); Barberet, Ph.; Bourret, S.; Devès, G.; Gordillo, N.; Michelet, C. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Le Trequesser, Q. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB, UPR9048) CNRS, Université de Bordeaux, 87 avenue du Dr. A. Schweitzer, Pessac F-33608 (France); Marques, A.C. [IST/IPFN, Universidade de Lisboa, Campus Tecnológico e Nuclear, E.N.10, 2686-953 Sacavém (Portugal); Seznec, H. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Silva, R.C. da [IST/IPFN, Universidade de Lisboa, Campus Tecnológico e Nuclear, E.N.10, 2686-953 Sacavém (Portugal)

    2014-07-15

    The tomographic reconstruction of biological specimens requires robust algorithms, able to deal with low density contrast and low element concentrations. At the IST/ITN microprobe facility new GPU-accelerated reconstruction software, JPIXET, has been developed, which can significantly increase the speed of quantitative reconstruction of Proton Induced X-ray Emission Tomography (PIXE-T) data. It has a user-friendly graphical user interface for pre-processing, data analysis and reconstruction of PIXE-T and Scanning Transmission Ion Microscopy Tomography (STIM-T). The reconstruction of PIXE-T data is performed using either an algorithm based on a GPU-accelerated version of the Maximum Likelihood Expectation Maximisation (MLEM) method or a GPU-accelerated version of the Discrete Image Space Reconstruction Algorithm (DISRA) (Sakellariou (2001) [2]). The original DISRA, its accelerated version, and the MLEM algorithm, were compared for the reconstruction of a biological sample of Caenorhabditis elegans – a small worm. This sample was analysed at the microbeam line of the AIFIRA facility of CENBG, Bordeaux. A qualitative PIXE-T reconstruction was obtained using the CENBG software package TomoRebuild (Habchi et al. (2013) [6]). The effects of pre-processing and experimental conditions on the elemental concentrations are discussed.

  2. Landslide Susceptibility Assessment Using Frequency Ratio Technique with Iterative Random Sampling

    Directory of Open Access Journals (Sweden)

    Hyun-Joo Oh

    2017-01-01

    Full Text Available This paper assesses the performance of the landslide susceptibility analysis using frequency ratio (FR with an iterative random sampling. A pair of before-and-after digital aerial photographs with 50 cm spatial resolution was used to detect landslide occurrences in Yongin area, Korea. Iterative random sampling was run ten times in total and each time it was applied to the training and validation datasets. Thirteen landslide causative factors were derived from the topographic, soil, forest, and geological maps. The FR scores were calculated from the causative factors and training occurrences repeatedly ten times. The ten landslide susceptibility maps were obtained from the integration of causative factors that assigned FR scores. The landslide susceptibility maps were validated by using each validation dataset. The FR method achieved susceptibility accuracies from 89.48% to 93.21%. And the landslide susceptibility accuracy of the FR method is higher than 89%. Moreover, the ten times iterative FR modeling may contribute to a better understanding of a regularized relationship between the causative factors and landslide susceptibility. This makes it possible to incorporate knowledge-driven considerations of the causative factors into the landslide susceptibility analysis and also be extensively used to other areas.

  3. Arsenic, Antimony, Chromium, and Thallium Speciation in Water and Sediment Samples with the LC-ICP-MS Technique

    Directory of Open Access Journals (Sweden)

    Magdalena Jabłońska-Czapla

    2015-01-01

    Full Text Available Chemical speciation is a very important subject in the environmental protection, toxicology, and chemical analytics due to the fact that toxicity, availability, and reactivity of trace elements depend on the chemical forms in which these elements occur. Research on low analyte levels, particularly in complex matrix samples, requires more and more advanced and sophisticated analytical methods and techniques. The latest trends in this field concern the so-called hyphenated techniques. Arsenic, antimony, chromium, and (underestimated thallium attract the closest attention of toxicologists and analysts. The properties of those elements depend on the oxidation state in which they occur. The aim of the following paper is to answer the question why the speciation analytics is so important. The paper also provides numerous examples of the hyphenated technique usage (e.g., the LC-ICP-MS application in the speciation analysis of chromium, antimony, arsenic, or thallium in water and bottom sediment samples. An important issue addressed is the preparation of environmental samples for speciation analysis.

  4. An intercomparison of sampling techniques among five European laboratories for measurements of radiocaesium in upland pasture and soil

    International Nuclear Information System (INIS)

    Nielsen, S.P.; Aarkrog, A.; Colgan, P.A.; McGee, E.; Synnott, H.J.; Johansson, K.J.; Horrill, A.D.; Kennedy, V.H.; Barbayiannis, N.

    1992-02-01

    An intercomparison of sampling procedures used by five European laboratories for the determination of radiocaesium in vegetation and peaty soil was carried out at two locations in Cumbria. The soil sampling procedures included th ecollection of depth profiles in order to obtain information on the vertical distribution of radiocaesium in addition to the total deposition. The number of samples taken by each laboratory varied from one to five. The multiple sampling has given information on the homogeneity of the parameters studied at each location. The parameters comprise soil bulk densities, total deposition of 137 Cs, deposition of 137 Cs in three soil layers, biomass densities, concentrations of 137 Cs in pasture, and activity ratios ( 134 Cs/ 137 Cs) in soil and vegetation. The determination of total deposition of 137 Cs gave no indication of differences between the laboratories. The total depositions of 134 Cs and 137 Cs observed at one site were compared with levels obtained from another study and the two sets of data were found to be in good agreement. The results from the soil profiles do indicate significant differences between laboratories. This covers the vertical distributions of 137 Cs deposition including the 134 Cs/ 137 Cs-activity ratios as well as the soil bulk densities. One laboratory using a coring technique observed difficulties during sampling due to compression of the soil. The coring technique should thus be avoided or applied with extreme care for the sampling of depth profiles in peaty soil. The results from the sampling of pasture show no indication of differences between the laboratories. For the parameters studied the observed variabilities across soil depths and locations range from 10% to 82% in terms of relative standard deviations. A comparison across all results at the two locations indicate a 50% higher field variability at one of the sites relative to the other. (au) (24 tabs., 9 ills., 3 refs.)

  5. Evaluation of vacuum microwave-assisted extraction technique for the extraction of antioxidants from plant samples.

    Science.gov (United States)

    Xiao, Xiao-Hua; Wang, Jun-Xia; Wang, Gang; Wang, Jia-Yue; Li, Gong-Ke

    2009-12-18

    In the present work, vacuum microwave-assisted extraction (VMAE) was to perform microwave-assisted extraction in vacuum. Two well-known antioxidants, vitamin C from guava and green pepper, and vitamin E (alpha-tocopherol and gamma-tocopherol) from soybean and tea leaves, which were easy to be oxidized, were chosen as representative target compounds for the evaluation of VMAE. The extraction yields of vitamin C, alpha-tocopherol and gamma-tocopherol in VMAE and those in MAE performed in atmosphere (air-MAE) were compared and the effects of extraction time, extraction temperature and sample matrix were studied. Moreover, the effects of the oxygen and subpressure invacuo were also discussed via performed MAE in N(2) atmosphere (N(2)-MAE). The extraction yields of vitamin C, alpha-tocopherol and gamma-tocopherol in VMAE were higher than that in air-MAE, 35% increments of vitamin C from green pepper, 22% increments of alpha-tocopherol and 47% increments of gamma-tocopherol from tea leaves were obtained, respectively. The comparable increased extraction yields of vitamin C, alpha-tocopherol and gamma-tocopherol in N(2)-MAE to that in air-MAE confirmed that oxygen in system was the crucial factor for the oxidation of vitamin C and vitamin E, VMAE was beneficial for the extraction of these oxygen-sensitive compounds. In addition, the subpressure invacuo in the VMAE system also showed positive affect on the extraction yields. On the basis of preventing oxidation and improving extraction efficiency of target compounds because of less oxygen and subpressure invacuo in the extraction system, VMAE has good potential for the extraction of oxygen-sensitive and thermosensitive compounds from plant samples.

  6. Analysis of plutonium isotopes in marine samples by radiometric, ICP-MS and AMS techniques

    International Nuclear Information System (INIS)

    Lee, S.H.; Gastaud, J.; La Rosa, J.J.; Liong Wee Kwong, L.; Povinec, P.P.; Wyse, E.

    2001-01-01

    IAEA reference materials (radionuclides in the marine environment) collected in areas affected by nuclear reprocessing plants and nuclear weapons tests have been analysed by semiconductor alpha-spectrometry (SAS), liquid scintillation spectrometry (LSS) and mass spectrometric techniques (high resolution ICP-MS and AMS) with the aim of developing analytical procedures and to study the geochemical behavior of plutonium in the marine environment. The Pu results obtained by SAS, ICP-MS and AMS were in reasonably good agreement (R 2 = 0.99). The mean atom ratios of 240 Pu/ 239 Pu in IAEA reference materials, IAEA-134, 135 and 381 were (0.212±0.010), (0.211±0.004) and (0.242±0.004), respectively. IAEA-384 (Fangataufa Lagoon Sediment) gave a 240 Pu/ 239 Pu mean atom ratio of 0.051±0.001. The results of 241 Pu obtained buy ICP-MS and LSS also show reasonable agreement (R 2 = 0.91). Pu isotopic signatures were useful in tracing Pu origin and in interpreting biogeochemical processes involving Pu in the marine environment. (author)

  7. Elemental analysis of different varieties of rice samples using XRF technique

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Jaspreet, E-mail: gillpreet05051812@gmail.com; Kumar, Anil, E-mail: gilljaspreet06@gmail.com [Department of Basic and Applied Physics, Punjabi University, Patiala 147002 (India)

    2016-05-06

    Rice is most consumed staple food in the world providing over 21% of the calorie intake of world’s population having high yielding capacity. Elements detected in rice are Al, As, Br, Cd, Cl, Co, Cs, Cu, Fe, Hg, K, Mg, Mn, Mo, Rb, Se and Zn by using Instrumental Neutron Activation with k0 standardization (R. Jayasekera etal,2004). Some of these trace elements are C, H, O, N, S, Ca, P, K, Na, Cl, Mn, Ti, Mg, Cu, Fe, Ni, Si and Zn are essential for growth of human physique The deficiency or excess of these elements in food is known to cause a variety of malnutrition or health disorders in the world. Every year, various varieties of rice are launched by Punjab Agriculture University, Ludhiana. The main purpose of which is to increases the yield to attain the maximum profit. But this leads to changing the elemental concentration in them, which may affect the human health according to variation in the nutrition values. The main objective is to study the presence of elemental concentration in various varieties of rice using EDXRF technique.

  8. Elemental analysis of different varieties of rice samples using XRF technique

    International Nuclear Information System (INIS)

    Kaur, Jaspreet; Kumar, Anil

    2016-01-01

    Rice is most consumed staple food in the world providing over 21% of the calorie intake of world’s population having high yielding capacity. Elements detected in rice are Al, As, Br, Cd, Cl, Co, Cs, Cu, Fe, Hg, K, Mg, Mn, Mo, Rb, Se and Zn by using Instrumental Neutron Activation with k0 standardization (R. Jayasekera etal,2004). Some of these trace elements are C, H, O, N, S, Ca, P, K, Na, Cl, Mn, Ti, Mg, Cu, Fe, Ni, Si and Zn are essential for growth of human physique The deficiency or excess of these elements in food is known to cause a variety of malnutrition or health disorders in the world. Every year, various varieties of rice are launched by Punjab Agriculture University, Ludhiana. The main purpose of which is to increases the yield to attain the maximum profit. But this leads to changing the elemental concentration in them, which may affect the human health according to variation in the nutrition values. The main objective is to study the presence of elemental concentration in various varieties of rice using EDXRF technique.

  9. Subsurface stormflow modeling with sensitivity analysis using a Latin-hypercube sampling technique

    International Nuclear Information System (INIS)

    Gwo, J.P.; Toran, L.E.; Morris, M.D.; Wilson, G.V.

    1994-09-01

    Subsurface stormflow, because of its dynamic and nonlinear features, has been a very challenging process in both field experiments and modeling studies. The disposal of wastes in subsurface stormflow and vadose zones at Oak Ridge National Laboratory, however, demands more effort to characterize these flow zones and to study their dynamic flow processes. Field data and modeling studies for these flow zones are relatively scarce, and the effect of engineering designs on the flow processes is poorly understood. On the basis of a risk assessment framework and a conceptual model for the Oak Ridge Reservation area, numerical models of a proposed waste disposal site were built, and a Latin-hypercube simulation technique was used to study the uncertainty of model parameters. Four scenarios, with three engineering designs, were simulated, and the effectiveness of the engineering designs was evaluated. Sensitivity analysis of model parameters suggested that hydraulic conductivity was the most influential parameter. However, local heterogeneities may alter flow patterns and result in complex recharge and discharge patterns. Hydraulic conductivity, therefore, may not be used as the only reference for subsurface flow monitoring and engineering operations. Neither of the two engineering designs, capping and French drains, was found to be effective in hydrologically isolating downslope waste trenches. However, pressure head contours indicated that combinations of both designs may prove more effective than either one alone

  10. Use of higher order signal moments and high speed digital sampling technique for neutron flux measurements

    Science.gov (United States)

    Baers, L. B.; Gutierrez, T. Rivero; Mendoza, R. A. Carrillo; Santana, G. Jimenez

    1993-08-01

    The second (conventional variance or Campbell signal), the third, and the modified fourth order central signal moments associated with the amplified and filtered currents from two electrodes of an ex-core neutron sensitive fission detector were measured versus the reactor power of the 1-MW TRIGA reactor in Mexico City. Two channels of a high-speed (400-MHz) multiplexing data sampler and an analog-to-digital converter with 12-b resolution and 1-Mword buffer memory were used. The data were further retrieved into a PC, and estimates for autocorrelation and cross-correlation moments up to the fifth order, coherence, skewness, excess, etc., quantities were calculated offline. Five-mode operation of the detector was achieved, including conventional counting rates and currents in agreement with theory and the authors' previous results with analog techniques. The signals are proportional to the neutron flux and reactor power in some flux ranges. The suppression of background noise is improved and the lower limit of the measurement range is extended as the order of moment is increased, in agreement with theory.

  11. Introduction to body composition assessment using the deuterium dilution technique with analysis of saliva samples by fourier transform infrared spectrometry

    International Nuclear Information System (INIS)

    2010-01-01

    For many years, the IAEA has fostered the more widespread use of stable isotope techniques to assess body composition in different population groups to address priority areas in public health nutrition in Member States. The objective is to support national and regional nutrition projects through both the IAEA's technical cooperation programme and its coordinated research projects. In particular, during the last few years, the increased access to analyses of deuterium enrichment by Fourier transform infrared (FTIR) spectrometry has increased the application of this technique in Africa, Asia and Latin America. This publication was developed by an international group of experts to provide practical, hands-on guidance in the use of this technique in settings where the analysis of deuterium enrichment in saliva samples will be made by FTIR. It is targeted at new users of this technique, for example nutritionists, analytical chemists and other professionals. More detailed information on the theoretical background and the practical application of state of the art methodologies to monitor changes in body composition can be found in an IAEA publication entitled Assessment of Body Composition and Total Energy Expenditure in Humans by Stable Isotope Techniques (IAEA Human Health Series No. 3)

  12. Design and building of a homemade sample changer for automation of the irradiation in neutron activation analysis technique

    International Nuclear Information System (INIS)

    Gago, Javier; Hernandez, Yuri; Baltuano, Oscar; Bedregal, Patricia; Lopez, Yon; Urquizo, Rafael

    2014-01-01

    Because the RP-10 research reactor operates during weekends, it was necessary to design and build a sample changer for irradiation as part of the automation process of neutron activation analysis technique. The device is formed by an aluminum turntable disk which can accommodate 19 polyethylene capsules, containing samples to be sent using the pneumatic transfer system from the laboratory to the irradiation position. The system is operate by a control switchboard to send and return capsules in a variable preset time and by two different ways, allowing the determination of short, medium and long lived radionuclides. Also another mechanism is designed called 'exchange valve' for changing travel paths (pipelines) allowing the irradiated samples to be stored for a longer time in the reactor hall. The system design has allowed complete automation of this technique, enabling the irradiation of samples without the presence of an analyst. The design, construction and operation of the device is described and presented in this article. (authors).

  13. Pithy Review on Routing Protocols in Wireless Sensor Networks and Least Routing Time Opportunistic Technique in WSN

    Science.gov (United States)

    Salman Arafath, Mohammed; Rahman Khan, Khaleel Ur; Sunitha, K. V. N.

    2018-01-01

    Nowadays due to most of the telecommunication standard development organizations focusing on using device-to-device communication so that they can provide proximity-based services and add-on services on top of the available cellular infrastructure. An Oppnets and wireless sensor network play a prominent role here. Routing in these networks plays a significant role in fields such as traffic management, packet delivery etc. Routing is a prodigious research area with diverse unresolved issues. This paper firstly focuses on the importance of Opportunistic routing and its concept then focus is shifted to prime aspect i.e. on packet reception ratio which is one of the highest QoS Awareness parameters. This paper discusses the two important functions of routing in wireless sensor networks (WSN) namely route selection using least routing time algorithm (LRTA) and data forwarding using clustering technique. Finally, the simulation result reveals that LRTA performs relatively better than the existing system in terms of average packet reception ratio and connectivity.

  14. Low incidence of clonality in cold water corals revealed through the novel use of a standardized protocol adapted to deep sea sampling

    Science.gov (United States)

    Becheler, Ronan; Cassone, Anne-Laure; Noël, Philippe; Mouchel, Olivier; Morrison, Cheryl L.; Arnaud-Haond, Sophie

    2017-11-01

    Sampling in the deep sea is a technical challenge, which has hindered the acquisition of robust datasets that are necessary to determine the fine-grained biological patterns and processes that may shape genetic diversity. Estimates of the extent of clonality in deep-sea species, despite the importance of clonality in shaping the local dynamics and evolutionary trajectories, have been largely obscured by such limitations. Cold-water coral reefs along European margins are formed mainly by two reef-building species, Lophelia pertusa and Madrepora oculata. Here we present a fine-grained analysis of the genotypic and genetic composition of reefs occurring in the Bay of Biscay, based on an innovative deep-sea sampling protocol. This strategy was designed to be standardized, random, and allowed the georeferencing of all sampled colonies. Clonal lineages discriminated through their Multi-Locus Genotypes (MLG) at 6-7 microsatellite markers could thus be mapped to assess the level of clonality and the spatial spread of clonal lineages. High values of clonal richness were observed for both species across all sites suggesting a limited occurrence of clonality, which likely originated through fragmentation. Additionally, spatial autocorrelation analysis underlined the possible occurrence of fine-grained genetic structure in several populations of both L. pertusa and M. oculata. The two cold-water coral species examined had contrasting patterns of connectivity among canyons, with among-canyon genetic structuring detected in M. oculata, whereas L. pertusa was panmictic at the canyon scale. This study exemplifies that a standardized, random and georeferenced sampling strategy, while challenging, can be applied in the deep sea, and associated benefits outlined here include improved estimates of fine grained patterns of clonality and dispersal that are comparable across sites and among species.

  15. Accelerated Evaluation of Automated Vehicles Safety in Lane-Change Scenarios Based on Importance Sampling Techniques.

    Science.gov (United States)

    Zhao, Ding; Lam, Henry; Peng, Huei; Bao, Shan; LeBlanc, David J; Nobukawa, Kazutoshi; Pan, Christopher S

    2017-03-01

    Automated vehicles (AVs) must be thoroughly evaluated before their release and deployment. A widely used evaluation approach is the Naturalistic-Field Operational Test (N-FOT), which tests prototype vehicles directly on the public roads. Due to the low exposure to safety-critical scenarios, N-FOTs are time consuming and expensive to conduct. In this paper, we propose an accelerated evaluation approach for AVs. The results can be used to generate motions of the other primary vehicles to accelerate the verification of AVs in simulations and controlled experiments. Frontal collision due to unsafe cut-ins is the target crash type of this paper. Human-controlled vehicles making unsafe lane changes are modeled as the primary disturbance to AVs based on data collected by the University of Michigan Safety Pilot Model Deployment Program. The cut-in scenarios are generated based on skewed statistics of collected human driver behaviors, which generate risky testing scenarios while preserving the statistical information so that the safety benefits of AVs in nonaccelerated cases can be accurately estimated. The cross-entropy method is used to recursively search for the optimal skewing parameters. The frequencies of the occurrences of conflicts, crashes, and injuries are estimated for a modeled AV, and the achieved accelerated rate is around 2000 to 20 000. In other words, in the accelerated simulations, driving for 1000 miles will expose the AV with challenging scenarios that will take about 2 to 20 million miles of real-world driving to encounter. This technique thus has the potential to greatly reduce the development and validation time for AVs.

  16. Model determination in a case of heterogeneity of variance using sampling techniques.

    Science.gov (United States)

    Varona, L; Moreno, C; Garcia-Cortes, L A; Altarriba, J

    1997-01-12

    A sampling determination procedure has been described in a case of heterogeneity of variance. The procedure makes use of the predictive distributions of each data given the rest of the data and the structure of the assumed model. The computation of these predictive distributions is carried out using a Gibbs Sampling procedure. The final criterion to compare between models is the Mean Square Error between the expectation of predictive distributions and real data. The procedure has been applied to a data set of weight at 210 days in the Spanish Pirenaica beef cattle breed. Three proposed models have been compared: (a) Single Trait Animal Model; (b) Heterogeneous Variance Animal Model; and (c) Multiple Trait Animal Model. After applying the procedure, the most adjusted model was the Heterogeneous Variance Animal Model. This result is probably due to a compromise between the complexity of the model and the amount of available information. The estimated heritabilities under the preferred model have been 0.489 ± 0.076 for males and 0.331 ± 0.082 for females. RESUMEN: Contraste de modelos en un caso de heterogeneidad de varianzas usando métodos de muestreo Se ha descrito un método de contraste de modelos mediante técnicas de muestreo en un caso de heterogeneidad de varianza entre sexos. El procedimiento utiliza las distribucviones predictivas de cada dato, dado el resto de datos y la estructura del modelo. El criterio para coparar modelos es el error cuadrático medio entre la esperanza de las distribuciones predictivas y los datos reales. El procedimiento se ha aplicado en datos de peso a los 210 días en la raza bovina Pirenaica. Se han propuesto tres posibles modelos: (a) Modelo Animal Unicaracter; (b) Modelo Animal con Varianzas Heterogéneas; (c) Modelo Animal Multicaracter. El modelo mejor ajustado fue el Modelo Animal con Varianzas Heterogéneas. Este resultado es probablemente debido a un compromiso entre la complejidad del modelo y la cantidad de datos

  17. Application of the spectrometric and radiochemical techniques in analyzing environmental samples from the Bulgarian Black Sea region

    International Nuclear Information System (INIS)

    Veleva, B.S.; Mungov, G.; Galabov, N.; Kolarova, M.; Guenchev, T.

    1999-01-01

    Development of the appropriate methods and techniques for marine and atmospheric radioactivity measurements in the NIMH-BAS during the last 5 years is presented. Approaches for pre-concentration of the radionuclides from the atmosphere and sea water samples followed with reliable radiochemical methods for radionuclides separation and low level counting are discussed. Dissolved radiocesium concentrations measured in a period of time starting in 1993 show some decrease with years and spatial variations probably due to the hydrophysical features of the sampling sides - the lower measured concentrations during 1995 and 1998 correspond to the lower salinity. Application of the radiochemical separation of Plutonium, Thorium, 90 Sr and Americium on the samples from the Bulgarian Black Sea coastal region is reported. (author)

  18. RIA of PGFsub(2α) and PGE2 in biological samples of different origin: comparison with the mass fragmentographic technique

    International Nuclear Information System (INIS)

    Cattabeni, F.; Borghi, C.; Folco, G.C.; Nicosia, S.; Spagnuolo, C.

    1979-01-01

    The aim of this paper is to describe some results obtained measuring PGFsub(2α) and PGE 2 with bioassay, RIA and mass fragmentography in samples of different biological origin such as rat brain cortex and human urine of normal subjects and patients with Bartter's Syndrome. The results reported here clearly indicate that the assay of PGFsub(2α) and PGE 2 require an accurate validation with different analytical techniques. In fact, RIA of PGFsub(2α) gave different results if the samples were of different origin. It can be concluded that all the methods today available for PGs measurements need to be accurately validated utilizing different assays and that this validation is required everytime the sample matrix is changed. (Auth.)

  19. Validation of a standard forensic anthropology examination protocol by measurement of applicability and reliability on exhumed and archive samples of known biological attribution.

    Science.gov (United States)

    Francisco, Raffaela Arrabaça; Evison, Martin Paul; Costa Junior, Moacyr Lobo da; Silveira, Teresa Cristina Pantozzi; Secchieri, José Marcelo; Guimarães, Marco Aurelio

    2017-10-01

    Forensic anthropology makes an important contribution to human identification and assessment of the causes and mechanisms of death and body disposal in criminal and civil investigations, including those related to atrocity, disaster and trafficking victim identification. The methods used are comparative, relying on assignment of questioned material to categories observed in standard reference material of known attribution. Reference collections typically originate in Europe and North America, and are not necessarily representative of contemporary global populations. Methods based on them must be validated when applied to novel populations. This study describes the validation of a standardized forensic anthropology examination protocol by application to two contemporary Brazilian skeletal samples of known attribution. One sample (n=90) was collected from exhumations following 7-35 years of burial and the second (n=30) was collected following successful investigations following routine case work. The study presents measurement of (1) the applicability of each of the methods: used and (2) the reliability with which the biographic parameters were assigned in each case. The results are discussed with reference to published assessments of methodological reliability regarding sex, age and-in particular-ancestry estimation. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Development of Spatial Scaling Technique of Forest Health Sample Point Information

    Science.gov (United States)

    Lee, J. H.; Ryu, J. E.; Chung, H. I.; Choi, Y. Y.; Jeon, S. W.; Kim, S. H.

    2018-04-01

    Forests provide many goods, Ecosystem services, and resources to humans such as recreation air purification and water protection functions. In rececnt years, there has been an increase in the factors that threaten the health of forests such as global warming due to climate change, environmental pollution, and the increase in interest in forests, and efforts are being made in various countries for forest management. Thus, existing forest ecosystem survey method is a monitoring method of sampling points, and it is difficult to utilize forests for forest management because Korea is surveying only a small part of the forest area occupying 63.7 % of the country (Ministry of Land Infrastructure and Transport Korea, 2016). Therefore, in order to manage large forests, a method of interpolating and spatializing data is needed. In this study, The 1st Korea Forest Health Management biodiversity Shannon;s index data (National Institute of Forests Science, 2015) were used for spatial interpolation. Two widely used methods of interpolation, Kriging method and IDW(Inverse Distance Weighted) method were used to interpolate the biodiversity index. Vegetation indices SAVI, NDVI, LAI and SR were used. As a result, Kriging method was the most accurate method.

  1. Study of organohalogens in foodstuffs and environmental samples by neutron activation analysis and related techniques

    International Nuclear Information System (INIS)

    Xu, D. D.; Mao, X.Y.; Ouyang, H.; Chai, Z. F.; Zhang, H.; Sun, H. B.

    2004-01-01

    Pine needles and foodstuffs collected from Beijing, China, were analyzed by instrumental neutron activation analysis (INAA) combined with organic solvent extraction for total halogens, extractable organohalogens (EOX) and extractable persistent organohalogens (EPOX). The INAA detection limits are 50 ng, 8 ng and 3.5 ng for Cl, Br and I, respectively. The contents and distribution patterns of organohalogens in these samples are reported. EOCl accounted for 0.013-0.016% and 1.6-2.7% of the total chlorine in yogurt and apples, respectively, which suggested that chlorine in foodstuffs mainly existed as inorganic species and non-extractable organochlorines. EOCl contents in pine needles and foodstuffs were noticeably higher than those of EOBr and EOI. For pine needles, yogurt and apples, 1.6-34%, 23-58% and 29-35% of EOCl remained as extractable persistent organochlorine (EPOCl), respectively. Pine needle containing higher EOCl contents in chemical industrial and traffic hub areas indicated that chemical industries and exhaust emission from vehicle were the main sources of organochlorines in the Beijing's air. The relative proportions of the known organochlorines (such as HCHs, DDTs, chlordanes, heptachlor, HCB and PCBs) to the total EOCl and EPOCl were 0.04-1.6% and 0.7-21.5%, respectively, which implied that the identity of species of a major portion of the EOCl and EPOCl measured in pine needles was unknown. (author)

  2. Analysis of sample composition using resonant ionization and time-of-flight techniques

    International Nuclear Information System (INIS)

    Cruz, A. de la; Ortiz, M.; Campos, J.

    1995-01-01

    This paper describes the setting up of a linear time-of-flight mass spectrometer that uses a tunable laser to produce resonant ionization of atoms and molecules in a pulsed supersonic beam. The ability of this kind of systems to produce time resolved signals for each species present in the sample allows quantitative analysis of its composition. By using a tunable laser beam of high spectral resolution to produce ionization, studies based on the structure of the photoionization spectra obtained are possible. In the present work several isotopic species of ordinary and deuterated benzene have been studied. Special care has been dedicated to the influence of the presence of a 13C in the ring. In this way values for spectroscopic constants and isotopic shifts have been obtained. Another system based in a homemade proportional counter has been designed and used is an auxiliary system. The results obtained with it are independent of these mentioned above and compatible with them. This system is of great utility for laser wavelength tuning to produce ionization in the mass spectrometer. (Author) 98 refs

  3. Analysis of sample composition using resonant ionization and time-of-flight techniques

    International Nuclear Information System (INIS)

    Luz, A. de la; Ortiz, M.; Campos, J.

    1995-01-01

    This paper describes the setting up of a linear time-of-flight mass spectrometer that uses a tunable laser to produce resonant ionization of atoms and molecules in a pulsed supersonic beam. The ability of this kind of systems to produce time resolved signals for each species present in the samples allows quantitative analysis of its composition. By using a tunable laser beam of high spectral resolution to produce ionization, studies based on the structure of the photoionization spectra obtained are possible. In the present work several isotopic species of ordinary and deuterated benzene have been studies. special care has been dedicated to the influence of the presence of a ''13 C in the ring. In this way values for spectroscopic constants and isotopic shifts have been obtained. Another system based in a homemade proportional counter has been designed and used as an auxiliary system. The results obtained with it are independent of these mentioned above and compatible with them. This system is of great utility for laser wavelength tuning to produce ionization in the mass spectrometer

  4. DEVELOPMENT OF SPATIAL SCALING TECHNIQUE OF FOREST HEALTH SAMPLE POINT INFORMATION

    Directory of Open Access Journals (Sweden)

    J. H. Lee

    2018-04-01

    Full Text Available Forests provide many goods, Ecosystem services, and resources to humans such as recreation air purification and water protection functions. In rececnt years, there has been an increase in the factors that threaten the health of forests such as global warming due to climate change, environmental pollution, and the increase in interest in forests, and efforts are being made in various countries for forest management. Thus, existing forest ecosystem survey method is a monitoring method of sampling points, and it is difficult to utilize forests for forest management because Korea is surveying only a small part of the forest area occupying 63.7 % of the country (Ministry of Land Infrastructure and Transport Korea, 2016. Therefore, in order to manage large forests, a method of interpolating and spatializing data is needed. In this study, The 1st Korea Forest Health Management biodiversity Shannon;s index data (National Institute of Forests Science, 2015 were used for spatial interpolation. Two widely used methods of interpolation, Kriging method and IDW(Inverse Distance Weighted method were used to interpolate the biodiversity index. Vegetation indices SAVI, NDVI, LAI and SR were used. As a result, Kriging method was the most acc