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Sample records for outcomes sampling sample

  1. 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

  2. Sampling depth confounds soil acidification outcomes

    Science.gov (United States)

    In the northern Great Plains (NGP) of North America, surface sampling depths of 0-15 or 0-20 cm are suggested for testing soil characteristics such as pH. However, acidification is often most pronounced near the soil surface. Thus, sampling deeper can potentially dilute (increase) pH measurements an...

  3. Graphical models for inference under outcome-dependent sampling

    DEFF Research Database (Denmark)

    Didelez, V; Kreiner, S; Keiding, N

    2010-01-01

    a node for the sampling indicator, assumptions about sampling processes can be made explicit. We demonstrate how to read off such graphs whether consistent estimation of the association between exposure and outcome is possible. Moreover, we give sufficient graphical conditions for testing and estimating......We consider situations where data have been collected such that the sampling depends on the outcome of interest and possibly further covariates, as for instance in case-control studies. Graphical models represent assumptions about the conditional independencies among the variables. By including...

  4. Adrenal Vein Sampling for Conn's Syndrome: Diagnosis and Clinical Outcomes.

    Science.gov (United States)

    Deipolyi, Amy R; Bailin, Alexander; Wicky, Stephan; Alansari, Shehab; Oklu, Rahmi

    2015-06-19

    Adrenal vein sampling (AVS) is the gold standard test to determine unilateral causes of primary aldosteronism (PA). We have retrospectively characterized our experience with AVS including concordance of AVS results and imaging, and describe the approach for the PA patient in whom bilateral AVS is unsuccessful. We reviewed the medical records of 85 patients with PA and compared patients who were treated medically and surgically on pre-procedure presentation and post-treatment outcomes, and evaluated how technically unsuccessful AVS results were used in further patient management. Out of the 92 AVS performed in 85 patients, AVS was technically successful bilaterally in 58 (63%) of cases. Either unsuccessful AVS prompted a repeat AVS, or results from the contralateral side and from CT imaging were used to guide further therapy. Patients who were managed surgically with adrenalectomy had higher initial blood pressure and lower potassium levels compared with patients who were managed medically. Adrenalectomy results in significantly decreased blood pressure and normalization of potassium levels. AVS can identify surgically curable causes of PA, but can be technically challenging. When one adrenal vein fails to be cannulated, results from the contralateral vein can be useful in conjunction with imaging and clinical findings to suggest further management.

  5. Boat sampling

    International Nuclear Information System (INIS)

    Citanovic, M.; Bezlaj, H.

    1994-01-01

    This presentation describes essential boat sampling activities: on site boat sampling process optimization and qualification; boat sampling of base material (beltline region); boat sampling of weld material (weld No. 4); problems accompanied with weld crown varieties, RPV shell inner radius tolerance, local corrosion pitting and water clarity. The equipment used for boat sampling is described too. 7 pictures

  6. Graph sampling

    OpenAIRE

    Zhang, L.-C.; Patone, M.

    2017-01-01

    We synthesise the existing theory of graph sampling. We propose a formal definition of sampling in finite graphs, and provide a classification of potential graph parameters. We develop a general approach of Horvitz–Thompson estimation to T-stage snowball sampling, and present various reformulations of some common network sampling methods in the literature in terms of the outlined graph sampling theory.

  7. Balanced sampling

    NARCIS (Netherlands)

    Brus, D.J.

    2015-01-01

    In balanced sampling a linear relation between the soil property of interest and one or more covariates with known means is exploited in selecting the sampling locations. Recent developments make this sampling design attractive for statistical soil surveys. This paper introduces balanced sampling

  8. Ensemble Sampling

    OpenAIRE

    Lu, Xiuyuan; Van Roy, Benjamin

    2017-01-01

    Thompson sampling has emerged as an effective heuristic for a broad range of online decision problems. In its basic form, the algorithm requires computing and sampling from a posterior distribution over models, which is tractable only for simple special cases. This paper develops ensemble sampling, which aims to approximate Thompson sampling while maintaining tractability even in the face of complex models such as neural networks. Ensemble sampling dramatically expands on the range of applica...

  9. Intracytoplasmic sperm injection outcomes with cryopreserved testicular sperm aspiration samples.

    Science.gov (United States)

    Roque, M; Valle, M; Marques, F; Sampaio, M; Geber, S

    2016-04-01

    Intracytoplasmic sperm injection (ICSI) may be performed with testicular frozen-thawed spermatozoa in patients with nonobstructive azoospermia (NOA). Sperm retrieval can be performed in advance of oocyte aspiration, as it may avoid the possibility of no recovery of spermatozoa on the day of oocyte pickup. There are few studies available in the literature concerning the use of frozen-thawed spermatozoa obtained from testicular sperm aspiration (TESA). To evaluate the effects and the outcomes of ICSI with frozen-thawed spermatozoa obtained by TESA, we performed a retrospective analysis of 43 ICSI cycles using frozen-thawed TESA. We obtained acceptable results with a fertilisation rate of 67.9%, an implantation rate (IR) of 17.1%, and clinical and ongoing pregnancy rates of 41.9% and 37.2% respectively. The results of this study suggest that performing ICSI using cryopreserved frozen-thawed testicular spermatozoa with TESA as a first option is a viable, safe, economic and effective method for patients with NOA. © 2015 Blackwell Verlag GmbH.

  10. Laser sampling

    International Nuclear Information System (INIS)

    Gorbatenko, A A; Revina, E I

    2015-01-01

    The review is devoted to the major advances in laser sampling. The advantages and drawbacks of the technique are considered. Specific features of combinations of laser sampling with various instrumental analytical methods, primarily inductively coupled plasma mass spectrometry, are discussed. Examples of practical implementation of hybrid methods involving laser sampling as well as corresponding analytical characteristics are presented. The bibliography includes 78 references

  11. Soil sampling

    International Nuclear Information System (INIS)

    Fortunati, G.U.; Banfi, C.; Pasturenzi, M.

    1994-01-01

    This study attempts to survey the problems associated with techniques and strategies of soil sampling. Keeping in mind the well defined objectives of a sampling campaign, the aim was to highlight the most important aspect of representativeness of samples as a function of the available resources. Particular emphasis was given to the techniques and particularly to a description of the many types of samplers which are in use. The procedures and techniques employed during the investigations following the Seveso accident are described. (orig.)

  12. Language sampling

    DEFF Research Database (Denmark)

    Rijkhoff, Jan; Bakker, Dik

    1998-01-01

    This article has two aims: [1] to present a revised version of the sampling method that was originally proposed in 1993 by Rijkhoff, Bakker, Hengeveld and Kahrel, and [2] to discuss a number of other approaches to language sampling in the light of our own method. We will also demonstrate how our...... sampling method is used with different genetic classifications (Voegelin & Voegelin 1977, Ruhlen 1987, Grimes ed. 1997) and argue that —on the whole— our sampling technique compares favourably with other methods, especially in the case of exploratory research....

  13. Sample preparation

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Sample preparation prior to HPLC analysis is certainly one of the most important steps to consider in trace or ultratrace analysis. For many years scientists have tried to simplify the sample preparation process. It is rarely possible to inject a neat liquid sample or a sample where preparation may not be any more complex than dissolution of the sample in a given solvent. The last process alone can remove insoluble materials, which is especially helpful with the samples in complex matrices if other interactions do not affect extraction. Here, it is very likely a large number of components will not dissolve and are, therefore, eliminated by a simple filtration process. In most cases, the process of sample preparation is not as simple as dissolution of the component interest. At times, enrichment is necessary, that is, the component of interest is present in very large volume or mass of material. It needs to be concentrated in some manner so a small volume of the concentrated or enriched sample can be injected into HPLC. 88 refs

  14. Sampling Development

    Science.gov (United States)

    Adolph, Karen E.; Robinson, Scott R.

    2011-01-01

    Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of…

  15. Environmental sampling

    International Nuclear Information System (INIS)

    Puckett, J.M.

    1998-01-01

    Environmental Sampling (ES) is a technology option that can have application in transparency in nuclear nonproliferation. The basic process is to take a sample from the environment, e.g., soil, water, vegetation, or dust and debris from a surface, and through very careful sample preparation and analysis, determine the types, elemental concentration, and isotopic composition of actinides in the sample. The sample is prepared and the analysis performed in a clean chemistry laboratory (CCL). This ES capability is part of the IAEA Strengthened Safeguards System. Such a Laboratory is planned to be built by JAERI at Tokai and will give Japan an intrinsic ES capability. This paper presents options for the use of ES as a transparency measure for nuclear nonproliferation

  16. Spherical sampling

    CERN Document Server

    Freeden, Willi; Schreiner, Michael

    2018-01-01

    This book presents, in a consistent and unified overview, results and developments in the field of today´s spherical sampling, particularly arising in mathematical geosciences. Although the book often refers to original contributions, the authors made them accessible to (graduate) students and scientists not only from mathematics but also from geosciences and geoengineering. Building a library of topics in spherical sampling theory it shows how advances in this theory lead to new discoveries in mathematical, geodetic, geophysical as well as other scientific branches like neuro-medicine. A must-to-read for everybody working in the area of spherical sampling.

  17. Fluidic sampling

    International Nuclear Information System (INIS)

    Houck, E.D.

    1992-01-01

    This paper covers the development of the fluidic sampler and its testing in a fluidic transfer system. The major findings of this paper are as follows. Fluidic jet samples can dependably produce unbiased samples of acceptable volume. The fluidic transfer system with a fluidic sampler in-line will transfer water to a net lift of 37.2--39.9 feet at an average ratio of 0.02--0.05 gpm (77--192 cc/min). The fluidic sample system circulation rate compares very favorably with the normal 0.016--0.026 gpm (60--100 cc/min) circulation rate that is commonly produced for this lift and solution with the jet-assisted airlift sample system that is normally used at ICPP. The volume of the sample taken with a fluidic sampler is dependant on the motive pressure to the fluidic sampler, the sample bottle size and on the fluidic sampler jet characteristics. The fluidic sampler should be supplied with fluid having the motive pressure of the 140--150 percent of the peak vacuum producing motive pressure for the jet in the sampler. Fluidic transfer systems should be operated by emptying a full pumping chamber to nearly empty or empty during the pumping cycle, this maximizes the solution transfer rate

  18. Sampling methods

    International Nuclear Information System (INIS)

    Loughran, R.J.; Wallbrink, P.J.; Walling, D.E.; Appleby, P.G.

    2002-01-01

    Methods for the collection of soil samples to determine levels of 137 Cs and other fallout radionuclides, such as excess 210 Pb and 7 Be, will depend on the purposes (aims) of the project, site and soil characteristics, analytical capacity, the total number of samples that can be analysed and the sample mass required. The latter two will depend partly on detector type and capabilities. A variety of field methods have been developed for different field conditions and circumstances over the past twenty years, many of them inherited or adapted from soil science and sedimentology. The use of them inherited or adapted from soil science and sedimentology. The use of 137 Cs in erosion studies has been widely developed, while the application of fallout 210 Pb and 7 Be is still developing. Although it is possible to measure these nuclides simultaneously, it is common for experiments to designed around the use of 137 Cs along. Caesium studies typically involve comparison of the inventories found at eroded or sedimentation sites with that of a 'reference' site. An accurate characterization of the depth distribution of these fallout nuclides is often required in order to apply and/or calibrate the conversion models. However, depending on the tracer involved, the depth distribution, and thus the sampling resolution required to define it, differs. For example, a depth resolution of 1 cm is often adequate when using 137 Cs. However, fallout 210 Pb and 7 Be commonly has very strong surface maxima that decrease exponentially with depth, and fine depth increments are required at or close to the soil surface. Consequently, different depth incremental sampling methods are required when using different fallout radionuclides. Geomorphic investigations also frequently require determination of the depth-distribution of fallout nuclides on slopes and depositional sites as well as their total inventories

  19. Evaluation of the International Outcome Inventory for Hearing Aids in a veteran sample.

    Science.gov (United States)

    Smith, Sherri L; Noe, Colleen M; Alexander, Genevieve C

    2009-06-01

    The International Outcome Inventory for Hearing Aids (IOI-HA) was developed as a global hearing aid outcome measure targeting seven outcome domains. The published norms were based on a private-pay sample who were fitted with analog hearing aids. The purpose of this study was to evaluate the psychometric properties of the IOI-HA and to establish normative data in a veteran sample. Survey. The participants were 131 male veterans (mean age of 74.3 years, SD = 7.4) who were issued hearing aids with digital signal processing (DSP). Hearing aids with DSP that were fitted bilaterally between 2005 and 2007. Veterans were mailed two copies of the IOI-HA. The participants were instructed to complete the first copy of the questionnaire immediately and the second copy in two weeks. The completed questionnaires were mailed to the laboratory. The psychometric properties of the questionnaire were evaluated. As suggested by Cox and colleagues, the participants were divided into two categories based on their unaided subjective hearing difficulty. The two categories were (1) those with less hearing difficulty (none-to-moderate category) and (2) those who report more hearing difficulty (moderately severe+ category). The norms from the current veteran sample then were compared to the original, published sample. For each hearing difficulty category, the critical difference values were calculated for each item and for the total score. A factor analysis showed that the IOI-HA in the veteran sample had the identical subscale structure as reported in the original sample. For the total scale, the internal consistency was good (Chronbach's alpha = 0.83), and the test-retest reliability was high (lambda = 0.94). Group and individual norms were developed for both hearing difficulty categories in the veteran sample. For each IOI-HA item, the critical difference scores were one response unit between two test sessions reflects a true change in outcome for a given domain. The results of this study

  20. Outcome-Dependent Sampling Design and Inference for Cox's Proportional Hazards Model.

    Science.gov (United States)

    Yu, Jichang; Liu, Yanyan; Cai, Jianwen; Sandler, Dale P; Zhou, Haibo

    2016-11-01

    We propose a cost-effective outcome-dependent sampling design for the failure time data and develop an efficient inference procedure for data collected with this design. To account for the biased sampling scheme, we derive estimators from a weighted partial likelihood estimating equation. The proposed estimators for regression parameters are shown to be consistent and asymptotically normally distributed. A criteria that can be used to optimally implement the ODS design in practice is proposed and studied. The small sample performance of the proposed method is evaluated by simulation studies. The proposed design and inference procedure is shown to be statistically more powerful than existing alternative designs with the same sample sizes. We illustrate the proposed method with an existing real data from the Cancer Incidence and Mortality of Uranium Miners Study.

  1. Outcome-Dependent Sampling Design and Inference for Cox’s Proportional Hazards Model

    Science.gov (United States)

    Yu, Jichang; Liu, Yanyan; Cai, Jianwen; Sandler, Dale P.; Zhou, Haibo

    2016-01-01

    We propose a cost-effective outcome-dependent sampling design for the failure time data and develop an efficient inference procedure for data collected with this design. To account for the biased sampling scheme, we derive estimators from a weighted partial likelihood estimating equation. The proposed estimators for regression parameters are shown to be consistent and asymptotically normally distributed. A criteria that can be used to optimally implement the ODS design in practice is proposed and studied. The small sample performance of the proposed method is evaluated by simulation studies. The proposed design and inference procedure is shown to be statistically more powerful than existing alternative designs with the same sample sizes. We illustrate the proposed method with an existing real data from the Cancer Incidence and Mortality of Uranium Miners Study. PMID:28090134

  2. Investigating Treatment Outcomes Across OCD Symptom Dimensions in a Clinical Sample of OCD Patients.

    Science.gov (United States)

    Chase, Tannah; Wetterneck, Chad T; Bartsch, Robert A; Leonard, Rachel C; Riemann, Bradley C

    2015-01-01

    Despite the heterogeneous nature of obsessive-compulsive disorder (OCD), many self-report assessments do not adequately capture the clinical picture presenting within each symptom dimension, particularly unacceptable thoughts (UTs). In addition, obsessions and ordering/arranging compulsions are often underrepresented in samples of treatment outcome studies for OCD. Such methodological discrepancies may obscure research findings comparing treatment outcomes across OCD symptom dimensions. This study aimed to improve upon previous research by investigating treatment outcomes across OCD symptom dimensions using the Dimensional Obsessive-Compulsive Scale, which offers a more comprehensive assessment of UTs. The study included a primarily residential sample of 134 OCD patients. Results indicated that there were no significant differences in treatment outcomes across symptom dimensions. However, the severity of UTs remained significantly greater than other symptom dimensions at both admission and discharge. Thus, it is possible that UTs may exhibit uniquely impairing features, compared with other symptom dimensions. It is also possible that these findings may reflect the characteristics of the residential OCD samples. These speculations as well as implications for OCD treatment and future research are discussed.

  3. Marijuana use and inpatient outcomes among hospitalized patients: analysis of the nationwide inpatient sample database

    OpenAIRE

    Vin?Raviv, Neomi; Akinyemiju, Tomi; Meng, Qingrui; Sakhuja, Swati; Hayward, Reid

    2016-01-01

    Abstract The purpose of this paper is to examine the relationship between marijuana use and health outcomes among hospitalized patients, including those hospitalized with a diagnosis of cancer. A total of 387,608 current marijuana users were identified based on ICD?9 codes for marijuana use among hospitalized patients in the Nationwide Inpatient Sample database between 2007 and 2011. Logistic regression analysis was performed to determine the association between marijuana use and heart failur...

  4. [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.

  5. Joint analysis of binary and quantitative traits with data sharing and outcome-dependent sampling.

    Science.gov (United States)

    Zheng, Gang; Wu, Colin O; Kwak, Minjung; Jiang, Wenhua; Joo, Jungnam; Lima, Joao A C

    2012-04-01

    We study the analysis of a joint association between a genetic marker with both binary (case-control) and quantitative (continuous) traits, where the quantitative trait values are only available for the cases due to data sharing and outcome-dependent sampling. Data sharing becomes common in genetic association studies, and the outcome-dependent sampling is the consequence of data sharing, under which a phenotype of interest is not measured for some subgroup. The trend test (or Pearson's test) and F-test are often, respectively, used to analyze the binary and quantitative traits. Because of the outcome-dependent sampling, the usual F-test can be applied using the subgroup with the observed quantitative traits. We propose a modified F-test by also incorporating the genotype frequencies of the subgroup whose traits are not observed. Further, a combination of this modified F-test and Pearson's test is proposed by Fisher's combination of their P-values as a joint analysis. Because of the correlation of the two analyses, we propose to use a Gamma (scaled chi-squared) distribution to fit the asymptotic null distribution for the joint analysis. The proposed modified F-test and the joint analysis can also be applied to test single trait association (either binary or quantitative trait). Through simulations, we identify the situations under which the proposed tests are more powerful than the existing ones. Application to a real dataset of rheumatoid arthritis is presented. © 2012 Wiley Periodicals, Inc.

  6. Turnover, staffing, skill mix, and resident outcomes in a national sample of US nursing homes.

    Science.gov (United States)

    Trinkoff, Alison M; Han, Kihye; Storr, Carla L; Lerner, Nancy; Johantgen, Meg; Gartrell, Kyungsook

    2013-12-01

    The authors examined the relationship of staff turnover to selected nursing home quality outcomes, in the context of staffing and skill mix. Staff turnover is a serious concern in nursing homes as it has been found to adversely affect care. When employee turnover is minimized, better care quality is more likely in nursing homes. Data from the National Nursing Home Survey, a nationally representative sample of US nursing homes, were linked to Nursing Home Compare quality outcomes and analyzed using logistic regression. Nursing homes with high certified nursing assistant turnover had significantly higher odds of pressure ulcers, pain, and urinary tract infections even after controlling for staffing, skill mix, bed size, and ownership. Nurse turnover was associated with twice the odds of pressure ulcers, although this was attenuated when staffing was controlled. This study suggests turnover may be more important in explaining nursing home (NH) outcomes than staffing and skill mix and should therefore be given greater emphasis.

  7. Burnout and Engagement: Relative Importance of Predictors and Outcomes in Two Health Care Worker Samples.

    Science.gov (United States)

    Fragoso, Zachary L; Holcombe, Kyla J; McCluney, Courtney L; Fisher, Gwenith G; McGonagle, Alyssa K; Friebe, Susan J

    2016-06-09

    This study's purpose was twofold: first, to examine the relative importance of job demands and resources as predictors of burnout and engagement, and second, the relative importance of engagement and burnout related to health, depressive symptoms, work ability, organizational commitment, and turnover intentions in two samples of health care workers. Nurse leaders (n = 162) and licensed emergency medical technicians (EMTs; n = 102) completed surveys. In both samples, job demands predicted burnout more strongly than job resources, and job resources predicted engagement more strongly than job demands. Engagement held more weight than burnout for predicting commitment, and burnout held more weight for predicting health outcomes, depressive symptoms, and work ability. Results have implications for the design, evaluation, and effectiveness of workplace interventions to reduce burnout and improve engagement among health care workers. Actionable recommendations for increasing engagement and decreasing burnout in health care organizations are provided. © 2016 The Author(s).

  8. Quantification of errors in ordinal outcome scales using shannon entropy: effect on sample size calculations.

    Science.gov (United States)

    Mandava, Pitchaiah; Krumpelman, Chase S; Shah, Jharna N; White, Donna L; Kent, Thomas A

    2013-01-01

    Clinical trial outcomes often involve an ordinal scale of subjective functional assessments but the optimal way to quantify results is not clear. In stroke, the most commonly used scale, the modified Rankin Score (mRS), a range of scores ("Shift") is proposed as superior to dichotomization because of greater information transfer. The influence of known uncertainties in mRS assessment has not been quantified. We hypothesized that errors caused by uncertainties could be quantified by applying information theory. Using Shannon's model, we quantified errors of the "Shift" compared to dichotomized outcomes using published distributions of mRS uncertainties and applied this model to clinical trials. We identified 35 randomized stroke trials that met inclusion criteria. Each trial's mRS distribution was multiplied with the noise distribution from published mRS inter-rater variability to generate an error percentage for "shift" and dichotomized cut-points. For the SAINT I neuroprotectant trial, considered positive by "shift" mRS while the larger follow-up SAINT II trial was negative, we recalculated sample size required if classification uncertainty was taken into account. Considering the full mRS range, error rate was 26.1%±5.31 (Mean±SD). Error rates were lower for all dichotomizations tested using cut-points (e.g. mRS 1; 6.8%±2.89; overall pdecrease in reliability. The resultant errors need to be considered since sample size may otherwise be underestimated. In principle, we have outlined an approach to error estimation for any condition in which there are uncertainties in outcome assessment. We provide the user with programs to calculate and incorporate errors into sample size estimation.

  9. Mental illness and housing outcomes among a sample of homeless men in an Australian urban centre.

    Science.gov (United States)

    Spicer, Bridget; Smith, David I; Conroy, Elizabeth; Flatau, Paul R; Burns, Lucy

    2015-05-01

    The over-representation of mental illness among homeless people across the globe is well documented. However, there is a dearth of Australian literature on the mental health needs of homeless individuals. Furthermore, longitudinal research examining the factors that contribute to better housing outcomes among this population is sparse. The aim of this research is to describe the mental illness profile of a sample of homeless men in an Australian urban centre (in Sydney) and examine the factors associated with better housing outcomes at 12-month follow-up. A longitudinal survey was administered to 253 homeless men who were involved in the Michael Project: a 3-year initiative which combined existing accommodation support services with assertive case management and access to coordinated additional specialist allied health and support services. A total of 107 participants were followed up 12 months later. The survey examined the demographics of the sample and lifetime mental disorder diagnoses, and also included psychological screeners for current substance use and dependence, psychological distress, psychosis, and post-traumatic stress. Consistent with existing literature, the prevalence of mental illness was significantly greater amongst this sample than the general Australian population. However, mental illness presentation was not associated with housing situation at 12-month follow-up. Instead, type of support service at baseline was the best predictor of housing outcome, wherein participants who received short to medium-term accommodation and support were significantly more likely to be housed in stable, long-term housing at the 12-month follow-up than participants who received outreach or emergency accommodation support. This study provides evidence to support an innovative support model for homeless people in Australia and contributes to the limited Australian research on mental illness in this population. © The Royal Australian and New Zealand College of

  10. An assessment of Lot Quality Assurance Sampling to evaluate malaria outcome indicators: extending malaria indicator surveys.

    Science.gov (United States)

    Biedron, Caitlin; Pagano, Marcello; Hedt, Bethany L; Kilian, Albert; Ratcliffe, Amy; Mabunda, Samuel; Valadez, Joseph J

    2010-02-01

    Large investments and increased global prioritization of malaria prevention and treatment have resulted in greater emphasis on programme monitoring and evaluation (M&E) in many countries. Many countries currently use large multistage cluster sample surveys to monitor malaria outcome indicators on a regional and national level. However, these surveys often mask local-level variability important to programme management. Lot Quality Assurance Sampling (LQAS) has played a valuable role for local-level programme M&E. If incorporated into these larger surveys, it would provide a comprehensive M&E plan at little, if any, extra cost. The Mozambique Ministry of Health conducted a Malaria Indicator Survey (MIS) in June and July 2007. We applied LQAS classification rules to the 345 sampled enumeration areas to demonstrate identifying high- and low-performing areas with respect to two malaria program indicators-'household possession of any bednet' and 'household possession of any insecticide-treated bednet (ITN)'. As shown by the MIS, no province in Mozambique achieved the 70% coverage target for household possession of bednets or ITNs. By applying LQAS classification rules to the data, we identify 266 of the 345 enumeration areas as having bednet coverage severely below the 70% target. An additional 73 were identified with low ITN coverage. This article demonstrates the feasibility of integrating LQAS into multistage cluster sampling surveys and using these results to support a comprehensive national, regional and local programme M&E system. Furthermore, in the recommendations we outlined how to integrate the Large Country-LQAS design into macro-surveys while still obtaining results available through current sampling practices.

  11. Statistical inference for the additive hazards model under outcome-dependent sampling.

    Science.gov (United States)

    Yu, Jichang; Liu, Yanyan; Sandler, Dale P; Zhou, Haibo

    2015-09-01

    Cost-effective study design and proper inference procedures for data from such designs are always of particular interests to study investigators. In this article, we propose a biased sampling scheme, an outcome-dependent sampling (ODS) design for survival data with right censoring under the additive hazards model. We develop a weighted pseudo-score estimator for the regression parameters for the proposed design and derive the asymptotic properties of the proposed estimator. We also provide some suggestions for using the proposed method by evaluating the relative efficiency of the proposed method against simple random sampling design and derive the optimal allocation of the subsamples for the proposed design. Simulation studies show that the proposed ODS design is more powerful than other existing designs and the proposed estimator is more efficient than other estimators. We apply our method to analyze a cancer study conducted at NIEHS, the Cancer Incidence and Mortality of Uranium Miners Study, to study the risk of radon exposure to cancer.

  12. Outcomes of couples with infidelity in a community-based sample of couple therapy.

    Science.gov (United States)

    Atkins, David C; Marín, Rebeca A; Lo, Tracy T Y; Klann, Notker; Hahlweg, Kurt

    2010-04-01

    Infidelity is an often cited problem for couples seeking therapy, but the research literature to date is very limited on couple therapy outcomes when infidelity is a problem. The current study is a secondary analysis of a community-based sample of couple therapy in Germany and Austria. Outcomes for 145 couples who reported infidelity as a problem in their relationship were compared with 385 couples who sought therapy for other reasons. Analyses based on hierarchical linear modeling revealed that infidelity couples were significantly more distressed and reported more depressive symptoms at the start of therapy but continued improving through the end of therapy and to 6 months posttherapy. At the follow-up assessment, infidelity couples were not statistically distinguishable from non-infidelity couples, replicating previous research. Sexual dissatisfaction did not depend on infidelity status. Although there was substantial missing data, sensitivity analyses suggested that the primary findings were not due to missing data. The current findings based on a large community sample replicated previous work from an efficacy trial and show generally optimistic results for couples in which there has been an affair. 2010 APA, all rights reserved

  13. Relational Intimacy Mediates Sexual Outcomes Associated With Impaired Sexual Function: Examination in a Clinical Sample.

    Science.gov (United States)

    Witherow, Marta Parkanyi; Chandraiah, Shambhavi; Seals, Samantha R; Sarver, Dustin E; Parisi, Kathryn E; Bugan, Antal

    2017-06-01

    Relational intimacy is hypothesized to underlie the association between female sexual functioning and various sexual outcomes, and married women and women with sexual dysfunction have been generally absent from prior studies investigating these associations, thus restricting generalizability. To investigate whether relational intimacy mediates sexual outcomes (sexual satisfaction, coital frequency, and sexual distress) in a sample of married women with and without impaired sexual functioning presenting in clinical settings. Using a cross-sectional design, 64 heterosexual married women with (n = 44) and without (n = 20) impaired sexual functioning completed a battery of validated measurements assessing relational intimacy, sexual dysfunction, sexual frequency, satisfaction, and distress. Intimacy measurements were combined using latent factor scores before analysis. Bias-corrected mediation models of the indirect effect were used to test mediation effects. Moderated mediation models examined whether indirect effects were influenced by age and marital duration. Patients completed the Female Sexual Function Index, the Couple's Satisfaction Index, the Sexual Satisfaction Scale for Women, the Inclusion of the Other in the Self Scale, and the Miller Social Intimacy Test. Mediation models showed that impaired sexual functioning is associated with all sexual outcomes directly and indirectly through relational intimacy. Results were predominantly independent of age and marital duration. Findings have important treatment implications for modifying interventions to focus on enhancing relational intimacy to improve the sexual functioning of women with impaired sexual functioning. The importance of the role relational intimacy plays in broad sexual outcomes of women with impaired sexual functioning is supported in clinically referred and married women. Latent factor scores to improve estimation of study constructs and the use of contemporary mediation analysis also are

  14. The significance of Sampling Design on Inference: An Analysis of Binary Outcome Model of Children’s Schooling Using Indonesian Large Multi-stage Sampling Data

    OpenAIRE

    Ekki Syamsulhakim

    2008-01-01

    This paper aims to exercise a rather recent trend in applied microeconometrics, namely the effect of sampling design on statistical inference, especially on binary outcome model. Many theoretical research in econometrics have shown the inappropriateness of applying i.i.dassumed statistical analysis on non-i.i.d data. These research have provided proofs showing that applying the iid-assumed analysis on a non-iid observations would result in an inflated standard errors which could make the esti...

  15. Clinical presentation and outcome of avoidant/restrictive food intake disorder in a Japanese sample.

    Science.gov (United States)

    Nakai, Yoshikatsu; Nin, Kazuko; Noma, Shun'ichi; Hamagaki, Seiji; Takagi, Ryuro; Teramukai, Satoshi; Wonderlich, Stephen A

    2017-01-01

    We conducted a study of the clinical presentation and outcome in patients with avoidant/restrictive food intake disorder (ARFID), aged 15-40years, and compared this group to an anorexia nervosa (AN) group in a Japanese sample. A retrospective chart review was completed on 245 patients with feeding and eating disorders (FEDs), analyzing prevalence, clinical presentation, psychopathological properties, and outcomes. Using the DSM-5 criteria, 27 (11.0%) out of the 245 patients with a FED met the criteria for ARFID at entry. All patients with ARFID were women. In terms of eating disorder symptoms, all patients with ARFID had restrictive eating related to emotional problems and/or gastrointestinal symptoms. However, none of the ARFID patients reported food avoidance related to sensory characteristics or functional dysphagia. Additionally, none of them exhibited binge eating or purging behaviors, and none of them reported excessive exercise. The ARFID group had a significantly shorter duration of illness, lower rates of admission history, and less severe psychopathology than the AN group. The ARFID group reported significantly better outcome results than the AN group. These results suggest that patients with ARFID in this study were clinically distinct from those with AN and somewhat different from pediatric patients with ARFID in previous studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Quantification of errors in ordinal outcome scales using shannon entropy: effect on sample size calculations.

    Directory of Open Access Journals (Sweden)

    Pitchaiah Mandava

    Full Text Available OBJECTIVE: Clinical trial outcomes often involve an ordinal scale of subjective functional assessments but the optimal way to quantify results is not clear. In stroke, the most commonly used scale, the modified Rankin Score (mRS, a range of scores ("Shift" is proposed as superior to dichotomization because of greater information transfer. The influence of known uncertainties in mRS assessment has not been quantified. We hypothesized that errors caused by uncertainties could be quantified by applying information theory. Using Shannon's model, we quantified errors of the "Shift" compared to dichotomized outcomes using published distributions of mRS uncertainties and applied this model to clinical trials. METHODS: We identified 35 randomized stroke trials that met inclusion criteria. Each trial's mRS distribution was multiplied with the noise distribution from published mRS inter-rater variability to generate an error percentage for "shift" and dichotomized cut-points. For the SAINT I neuroprotectant trial, considered positive by "shift" mRS while the larger follow-up SAINT II trial was negative, we recalculated sample size required if classification uncertainty was taken into account. RESULTS: Considering the full mRS range, error rate was 26.1%±5.31 (Mean±SD. Error rates were lower for all dichotomizations tested using cut-points (e.g. mRS 1; 6.8%±2.89; overall p<0.001. Taking errors into account, SAINT I would have required 24% more subjects than were randomized. CONCLUSION: We show when uncertainty in assessments is considered, the lowest error rates are with dichotomization. While using the full range of mRS is conceptually appealing, a gain of information is counter-balanced by a decrease in reliability. The resultant errors need to be considered since sample size may otherwise be underestimated. In principle, we have outlined an approach to error estimation for any condition in which there are uncertainties in outcome assessment. We

  17. Clinical Outcomes among Transferred Children with Ischemic and Hemorrhagic Strokes in the Nationwide Inpatient Sample.

    Science.gov (United States)

    Adil, Malik M; Vidal, Gabriel A; Beslow, Lauren A

    2016-11-01

    Children with ischemic stroke (IS) and hemorrhagic stroke (HS) may require interfacility transfer for higher level of care. We compared the characteristics and clinical outcomes of transferred and nontransferred children with IS and HS. Children aged 1-18 years admitted to hospitals in the United States from 2008 to 2011 with a primary discharge diagnosis of IS and HS were identified from the National Inpatient Sample database by ICD-9 codes. Using logistic regression, we estimated the odds ratios (OR) and 95% confidence intervals (CI) for in-hospital mortality and discharge to nursing facilities (versus discharge home) between transferred and nontransferred patients. Of the 2815 children with IS, 26.7% were transferred. In-hospital mortality and discharge to nursing facilities were not different between transferred and nontransferred children in univariable analysis or in multivariable analysis that adjusted for age, sex, and confounding factors. Of the 6879 children with HS, 27.1% were transferred. Transferred compared to nontransferred children had higher rates of both in-hospital mortality (8% versus 4%, P = .003) and discharge to nursing facilities (25% versus 20%, P = .03). After adjusting for age, sex, and confounding factors, in-hospital mortality (OR 1.5, 95% CI 1.1-2.4, P = .04) remained higher in transferred children, whereas discharge to nursing facilities was not different between the groups. HS but not IS was associated with worse outcomes for children transferred to another hospital compared to children who were not transferred. Additional study is needed to understand what factors may contribute to poorer outcomes among transferred children with HS. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  18. Drinking game participation and outcomes in a sample of Australian university students.

    Science.gov (United States)

    George, Amanda M; Zamboanga, Byron L

    2018-05-15

    Most drinking game (DG) research among university students has been conducted among USA college samples. The extent to which demographics and game type (e.g. team and sculling games) are linked to DG behaviours/consequences among non-USA students is not well understood. As such, the current study investigated characteristics of DG participation (and associated outcomes) among a sample of Australian university students. University students (N = 252; aged 18-24 years; 67% female) who had consumed alcohol in the prior year completed an online survey. Measures included demographics, DG behaviours (lifetime, frequency and consumption) and gaming-specific consequences. Most of the students reported lifetime DG participation (85%). Among those who played a DG in the prior 6 months (69%), most had experienced a negative gaming-specific consequence. While team games were the most popular DG played, regression analysis demonstrated that participation in games which encouraged consumption (e.g. sculling) were associated with increased alcohol consumption during play. In addition to being older, playing DGs more frequently, and consuming more alcohol while playing, participation in both consumption and dice games (e.g. 7-11, doubles) predicted more negative gaming-specific consequences. DG participation is common among Australian university students, as it is in other parts of the world. The importance of game type is clear, particularly the risk of consumption games. Findings could help inform interventions to reduce participation in consumption games and identify students who might be especially at-risk for experiencing negative DG consequences. © 2018 Australasian Professional Society on Alcohol and other Drugs.

  19. Smoking, activity level and exercise test outcomes in a young population sample without cardiopulmonary disease.

    Science.gov (United States)

    Vozoris, N T; O'donnell, D E

    2015-01-01

    Whether reduced activity level and exercise intolerance precede the clinical diagnosis of cardiopulmonary disorders in smokers is not known. We examined activity level and exercise test outcomes in a young population-based sample without overt cardiopulmonary disease, differentiating by smoking history. This was a multiyear cross-sectional study using United States National Health and Nutrition Examination Survey data from 1999-2004. Self-reported activity level and incremental exercise treadmill testing were obtained on survey participants ages 20-49 years, excluding individuals with cardio-pulmonary disease. Three thousand seven hundred and one individuals completed exercise testing. Compared to never smokers, current smokers with >10 pack years reported significantly higher odds of little or no recreation, sport, or physical activity (adjusted OR 1.62; 95% CI 1.12-2.35). Mean perceived exertion ratings (Borg 6-20) at an estimated standardized workload were significantly greater among current smokers (18.3-18.6) compared to never (17.3) and former smokers (17.9) (psmoking abstinence was associated with significantly lower likelihood of low estimated peak oxygen uptake categorization (psmoking cessation, these results set the stage for future studies that examine mechanisms of activity restriction in young smokers and the utility of measures of activity restriction in the earlier diagnosis of smoking-related diseases.

  20. Adrenal Vein Sampling for Conn’s Syndrome: Diagnosis and Clinical Outcomes

    Directory of Open Access Journals (Sweden)

    Amy R. Deipolyi

    2015-06-01

    Full Text Available Adrenal vein sampling (AVS is the gold standard test to determine unilateral causes of primary aldosteronism (PA. We have retrospectively characterized our experience with AVS including concordance of AVS results and imaging, and describe the approach for the PA patient in whom bilateral AVS is unsuccessful. We reviewed the medical records of 85 patients with PA and compared patients who were treated medically and surgically on pre-procedure presentation and post-treatment outcomes, and evaluated how technically unsuccessful AVS results were used in further patient management. Out of the 92 AVS performed in 85 patients, AVS was technically successful bilaterally in 58 (63% of cases. Either unsuccessful AVS prompted a repeat AVS, or results from the contralateral side and from CT imaging were used to guide further therapy. Patients who were managed surgically with adrenalectomy had higher initial blood pressure and lower potassium levels compared with patients who were managed medically. Adrenalectomy results in significantly decreased blood pressure and normalization of potassium levels. AVS can identify surgically curable causes of PA, but can be technically challenging. When one adrenal vein fails to be cannulated, results from the contralateral vein can be useful in conjunction with imaging and clinical findings to suggest further management.

  1. Sample size calculations based on a difference in medians for positively skewed outcomes in health care studies

    Directory of Open Access Journals (Sweden)

    Aidan G. O’Keeffe

    2017-12-01

    Full Text Available Abstract Background In healthcare research, outcomes with skewed probability distributions are common. Sample size calculations for such outcomes are typically based on estimates on a transformed scale (e.g. log which may sometimes be difficult to obtain. In contrast, estimates of median and variance on the untransformed scale are generally easier to pre-specify. The aim of this paper is to describe how to calculate a sample size for a two group comparison of interest based on median and untransformed variance estimates for log-normal outcome data. Methods A log-normal distribution for outcome data is assumed and a sample size calculation approach for a two-sample t-test that compares log-transformed outcome data is demonstrated where the change of interest is specified as difference in median values on the untransformed scale. A simulation study is used to compare the method with a non-parametric alternative (Mann-Whitney U test in a variety of scenarios and the method is applied to a real example in neurosurgery. Results The method attained a nominal power value in simulation studies and was favourable in comparison to a Mann-Whitney U test and a two-sample t-test of untransformed outcomes. In addition, the method can be adjusted and used in some situations where the outcome distribution is not strictly log-normal. Conclusions We recommend the use of this sample size calculation approach for outcome data that are expected to be positively skewed and where a two group comparison on a log-transformed scale is planned. An advantage of this method over usual calculations based on estimates on the log-transformed scale is that it allows clinical efficacy to be specified as a difference in medians and requires a variance estimate on the untransformed scale. Such estimates are often easier to obtain and more interpretable than those for log-transformed outcomes.

  2. Modern survey sampling

    CERN Document Server

    Chaudhuri, Arijit

    2014-01-01

    Exposure to SamplingAbstract Introduction Concepts of Population, Sample, and SamplingInitial RamificationsAbstract Introduction Sampling Design, Sampling SchemeRandom Numbers and Their Uses in Simple RandomSampling (SRS)Drawing Simple Random Samples with and withoutReplacementEstimation of Mean, Total, Ratio of Totals/Means:Variance and Variance EstimationDetermination of Sample SizesA.2 Appendix to Chapter 2 A.More on Equal Probability Sampling A.Horvitz-Thompson EstimatorA.SufficiencyA.LikelihoodA.Non-Existence Theorem More Intricacies Abstract Introduction Unequal Probability Sampling StrategiesPPS Sampling Exploring Improved WaysAbstract Introduction Stratified Sampling Cluster SamplingMulti-Stage SamplingMulti-Phase Sampling: Ratio and RegressionEstimationviiviii ContentsControlled SamplingModeling Introduction Super-Population ModelingPrediction Approach Model-Assisted Approach Bayesian Methods Spatial SmoothingSampling on Successive Occasions: Panel Rotation Non-Response and Not-at-Homes Weighting Adj...

  3. Systematic sampling with errors in sample locations

    DEFF Research Database (Denmark)

    Ziegel, Johanna; Baddeley, Adrian; Dorph-Petersen, Karl-Anton

    2010-01-01

    analysis using point process methods. We then analyze three different models for the error process, calculate exact expressions for the variances, and derive asymptotic variances. Errors in the placement of sample points can lead to substantial inflation of the variance, dampening of zitterbewegung......Systematic sampling of points in continuous space is widely used in microscopy and spatial surveys. Classical theory provides asymptotic expressions for the variance of estimators based on systematic sampling as the grid spacing decreases. However, the classical theory assumes that the sample grid...... is exactly periodic; real physical sampling procedures may introduce errors in the placement of the sample points. This paper studies the effect of errors in sample positioning on the variance of estimators in the case of one-dimensional systematic sampling. First we sketch a general approach to variance...

  4. Comparative analysis of whole mount processing and systematic sampling of radical prostatectomy specimens: pathological outcomes and risk of biochemical recurrence.

    Science.gov (United States)

    Salem, Shady; Chang, Sam S; Clark, Peter E; Davis, Rodney; Herrell, S Duke; Kordan, Yakup; Wills, Marcia L; Shappell, Scott B; Baumgartner, Roxelyn; Phillips, Sharon; Smith, Joseph A; Cookson, Michael S; Barocas, Daniel A

    2010-10-01

    Whole mount processing is more resource intensive than routine systematic sampling of radical retropubic prostatectomy specimens. We compared whole mount and systematic sampling for detecting pathological outcomes, and compared the prognostic value of pathological findings across pathological methods. We included men (608 whole mount and 525 systematic sampling samples) with no prior treatment who underwent radical retropubic prostatectomy at Vanderbilt University Medical Center between January 2000 and June 2008. We used univariate and multivariate analysis to compare the pathological outcome detection rate between pathological methods. Kaplan-Meier curves and the log rank test were used to compare the prognostic value of pathological findings across pathological methods. There were no significant differences between the whole mount and the systematic sampling groups in detecting extraprostatic extension (25% vs 30%), positive surgical margins (31% vs 31%), pathological Gleason score less than 7 (49% vs 43%), 7 (39% vs 43%) or greater than 7 (12% vs 13%), seminal vesicle invasion (8% vs 10%) or lymph node involvement (3% vs 5%). Tumor volume was higher in the systematic sampling group and whole mount detected more multiple surgical margins (each p systematic sampling yield similar pathological information. Each method stratifies patients into comparable risk groups for biochemical recurrence. Thus, while whole mount is more resource intensive, it does not appear to result in improved detection of clinically important pathological outcomes or prognostication. Copyright © 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  5. Subjective and objective outcomes from new BiCROS technology in a veteran sample.

    Science.gov (United States)

    Williams, Victoria A; McArdle, Rachel A; Chisolm, Theresa H

    2012-01-01

    . Overall, the objective (WIN) and subjective (SSQ, MarkeTrak, and open-ended questions) measures indicated that the new BiCROS provided better outcomes than the previous BiCROS system. In addition, an overlap of favorable results was seen across measures. Of the 39 participants, 95% reported improvements with the new BiCROS and chose to utilize the device regularly. The favorable objective and subjective outcomes indicate that the new BiCROS system is as good, or better than, what was previously utilized by our sample of veterans. American Academy of Audiology.

  6. Postoperative Outcomes in Graves' Disease Patients: Results from the Nationwide Inpatient Sample Database.

    Science.gov (United States)

    Rubio, Gustavo A; Koru-Sengul, Tulay; Vaghaiwalla, Tanaz M; Parikh, Punam P; Farra, Josefina C; Lew, John I

    2017-06-01

    Current surgical indications for Graves' disease include intractability to medical and/or radioablative therapy, compressive symptoms, and worsening ophthalmopathy. Total thyroidectomy for Graves' disease may be technically challenging and lead to untoward perioperative outcomes. This study examines outcomes in patients with Graves' disease who underwent total thyroidectomy and assesses its safety for this patient population. A retrospective cross-sectional analysis was performed using the Nationwide Inpatient Sample database from 2006 to 2011. Total thyroidectomy performed in patients with Graves' disease, benign multinodular goiter (MNG), and thyroid cancer was identified. Demographic factors, comorbidities, and postoperative complications were evaluated. Chi-square, one-way analysis of variance, and risk-adjusted multivariable logistic regression were performed. Of 215,068 patients who underwent total thyroidectomy during the study period, 11,205 (5.2%) had Graves' disease, 110,124 (51.2%) MNG, and 93,739 (43.6%) thyroid malignancy. Patients with Graves' disease were younger than MNG and thyroid cancer patients (M age  = 42.8 years vs. 55.5 and 51.0 years; p Graves' disease group included a higher proportion of women (p Graves' disease was independently associated with a higher risk of vocal-cord paralysis (odds ratio [OR] = 1.36 [confidence interval (CI) 1.08-1.69]), tracheostomy (OR = 1.35 [CI 1.1-1.67]), postoperative hypocalcemia (OR = 1.65 [CI 1.54-1.77]), and hematoma requiring reoperation (OR = 2.79 [CI 2.16-3.62]) compared to MNG patients. High-volume centers for total thyroidectomy were independently associated with lower risk of postoperative complications, including in patients with Graves' disease. Despite low overall morbidity following total thyroidectomy, Graves' disease patients are at increased risk of postoperative complications, including bleeding, vocal-cord paralysis, tracheostomy, and hypocalcemia. These risks appear

  7. Evaluation of three sampling methods to monitor outcomes of antiretroviral treatment programmes in low- and middle-income countries.

    Science.gov (United States)

    Tassie, Jean-Michel; Malateste, Karen; Pujades-Rodríguez, Mar; Poulet, Elisabeth; Bennett, Diane; Harries, Anthony; Mahy, Mary; Schechter, Mauro; Souteyrand, Yves; Dabis, François

    2010-11-10

    Retention of patients on antiretroviral therapy (ART) over time is a proxy for quality of care and an outcome indicator to monitor ART programs. Using existing databases (Antiretroviral in Lower Income Countries of the International Databases to Evaluate AIDS and Médecins Sans Frontières), we evaluated three sampling approaches to simplify the generation of outcome indicators. We used individual patient data from 27 ART sites and included 27,201 ART-naive adults (≥15 years) who initiated ART in 2005. For each site, we generated two outcome indicators at 12 months, retention on ART and proportion of patients lost to follow-up (LFU), first using all patient data and then within a smaller group of patients selected using three sampling methods (random, systematic and consecutive sampling). For each method and each site, 500 samples were generated, and the average result was compared with the unsampled value. The 95% sampling distribution (SD) was expressed as the 2.5(th) and 97.5(th) percentile values from the 500 samples. Overall, retention on ART was 76.5% (range 58.9-88.6) and the proportion of patients LFU, 13.5% (range 0.8-31.9). Estimates of retention from sampling (n = 5696) were 76.5% (SD 75.4-77.7) for random, 76.5% (75.3-77.5) for systematic and 76.0% (74.1-78.2) for the consecutive method. Estimates for the proportion of patients LFU were 13.5% (12.6-14.5), 13.5% (12.6-14.3) and 14.0% (12.5-15.5), respectively. With consecutive sampling, 50% of sites had SD within ±5% of the unsampled site value. Our results suggest that random, systematic or consecutive sampling methods are feasible for monitoring ART indicators at national level. However, sampling may not produce precise estimates in some sites.

  8. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  9. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2010-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  10. A review of empirical research related to the use of small quantitative samples in clinical outcome scale development.

    Science.gov (United States)

    Houts, Carrie R; Edwards, Michael C; Wirth, R J; Deal, Linda S

    2016-11-01

    There has been a notable increase in the advocacy of using small-sample designs as an initial quantitative assessment of item and scale performance during the scale development process. This is particularly true in the development of clinical outcome assessments (COAs), where Rasch analysis has been advanced as an appropriate statistical tool for evaluating the developing COAs using a small sample. We review the benefits such methods are purported to offer from both a practical and statistical standpoint and detail several problematic areas, including both practical and statistical theory concerns, with respect to the use of quantitative methods, including Rasch-consistent methods, with small samples. The feasibility of obtaining accurate information and the potential negative impacts of misusing large-sample statistical methods with small samples during COA development are discussed.

  11. Prevalence, 20-month incidence and outcome of unipolar depressive disorders in a community sample of adolescents

    NARCIS (Netherlands)

    Oldehinkel, AJ; Wittchen, HU; Schuster, P

    Background. This article presents prospective longitudinal findings on prevalence, incidence, patterns of change and stability of depressive disorders in a community sample of 1228 adolescents. Methods. Data were collected at baseline and follow-up (20 months later) in a representative population

  12. On the Sampling

    OpenAIRE

    Güleda Doğan

    2017-01-01

    This editorial is on statistical sampling, which is one of the most two important reasons for editorial rejection from our journal Turkish Librarianship. The stages of quantitative research, the stage in which we are sampling, the importance of sampling for a research, deciding on sample size and sampling methods are summarised briefly.

  13. Information sampling behavior with explicit sampling costs

    Science.gov (United States)

    Juni, Mordechai Z.; Gureckis, Todd M.; Maloney, Laurence T.

    2015-01-01

    The decision to gather information should take into account both the value of information and its accrual costs in time, energy and money. Here we explore how people balance the monetary costs and benefits of gathering additional information in a perceptual-motor estimation task. Participants were rewarded for touching a hidden circular target on a touch-screen display. The target’s center coincided with the mean of a circular Gaussian distribution from which participants could sample repeatedly. Each “cue” — sampled one at a time — was plotted as a dot on the display. Participants had to repeatedly decide, after sampling each cue, whether to stop sampling and attempt to touch the hidden target or continue sampling. Each additional cue increased the participants’ probability of successfully touching the hidden target but reduced their potential reward. Two experimental conditions differed in the initial reward associated with touching the hidden target and the fixed cost per cue. For each condition we computed the optimal number of cues that participants should sample, before taking action, to maximize expected gain. Contrary to recent claims that people gather less information than they objectively should before taking action, we found that participants over-sampled in one experimental condition, and did not significantly under- or over-sample in the other. Additionally, while the ideal observer model ignores the current sample dispersion, we found that participants used it to decide whether to stop sampling and take action or continue sampling, a possible consequence of imperfect learning of the underlying population dispersion across trials. PMID:27429991

  14. 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.

  15. How Sample Size Affects a Sampling Distribution

    Science.gov (United States)

    Mulekar, Madhuri S.; Siegel, Murray H.

    2009-01-01

    If students are to understand inferential statistics successfully, they must have a profound understanding of the nature of the sampling distribution. Specifically, they must comprehend the determination of the expected value and standard error of a sampling distribution as well as the meaning of the central limit theorem. Many students in a high…

  16. Outcome Measurement Using Naturalistic Language Samples: A Feasibility Pilot Study Using Language Transcription Software and Speech and Language Therapy Assistants

    Science.gov (United States)

    Overton, Sarah; Wren, Yvonne

    2014-01-01

    The ultimate aim of intervention for children with language impairment is an improvement in their functional language skills. Baseline and outcome measurement of this is often problematic however and practitioners commonly resort to using formal assessments that may not adequately reflect the child's competence. Language sampling,…

  17. Radioactivity in environmental samples

    International Nuclear Information System (INIS)

    Fornaro, Laura

    2001-01-01

    The objective of this practical work is to familiarize the student with radioactivity measures in environmental samples. For that were chosen samples a salt of natural potassium, a salt of uranium or torio and a sample of drinkable water

  18. DNA Sampling Hook

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The DNA Sampling Hook is a significant improvement on a method of obtaining a tissue sample from a live fish in situ from an aquatic environment. A tissue sample...

  19. Iowa Geologic Sampling Points

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Point locations of geologic samples/files in the IGS repository. Types of samples include well cuttings, outcrop samples, cores, drillers logs, measured sections,...

  20. Network and adaptive sampling

    CERN Document Server

    Chaudhuri, Arijit

    2014-01-01

    Combining the two statistical techniques of network sampling and adaptive sampling, this book illustrates the advantages of using them in tandem to effectively capture sparsely located elements in unknown pockets. It shows how network sampling is a reliable guide in capturing inaccessible entities through linked auxiliaries. The text also explores how adaptive sampling is strengthened in information content through subsidiary sampling with devices to mitigate unmanageable expanding sample sizes. Empirical data illustrates the applicability of both methods.

  1. Sampling procedures and tables

    International Nuclear Information System (INIS)

    Franzkowski, R.

    1980-01-01

    Characteristics, defects, defectives - Sampling by attributes and by variables - Sample versus population - Frequency distributions for the number of defectives or the number of defects in the sample - Operating characteristic curve, producer's risk, consumer's risk - Acceptable quality level AQL - Average outgoing quality AOQ - Standard ISQ 2859 - Fundamentals of sampling by variables for fraction defective. (RW)

  2. The outcome of dimethylglyoxime testing in a sample of cell phones in Denmark

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Johansen, Jeanne D; Zachariae, Claus

    2008-01-01

    BACKGROUND: Nickel dermatitis may be caused by frequent and prolonged use of cell phones. Because little is known about the frequency of nickel release from cell phones, it is difficult to estimate the risk of nickel sensitization and dermatitis among their users. OBJECTIVE: Inspired by a recent...... case of nickel dermatitis from prolonged cell phone use, the frequency of dimethylglyoxime (DMG)-positive cell phones on the Danish market was investigated. METHODS: Five major cell phone companies were contacted. Two were visited, and the DMG test was performed on a sample of their products. RESULTS...... phones from the Danish market. Prolonged use of cell phones may in some cases fulfil the criteria for items included in the European Union Nickel Directive. We believe that this new cause of nickel dermatitis should be carefully followed and that regulatory steps may be necessary....

  3. The outcome of dimethylglyoxime testing in a sample of cell phones in Denmark

    DEFF Research Database (Denmark)

    Thyssen, J.P.; Johansen, J.D.; Zachariae, C.

    2008-01-01

    Background: Nickel dermatitis may be caused by frequent and prolonged use of cell phones. Because little is known about the frequency of nickel release from cell phones, it is difficult to estimate the risk of nickel sensitization and dermatitis among their users. Objective: Inspired by a recent...... case of nickel dermatitis from prolonged cell phone use, the frequency of dimethylglyoxime (DMG)-positive cell phones on the Danish market was investigated. Methods: Five major cell phone companies were contacted. Two were visited, and the DMG test was performed on a sample of their products. Results...... phones from the Danish market. Prolonged use of cell phones may in some cases fulfil the criteria for items included in the European Union Nickel Directive. We believe that this new cause of nickel dermatitis should be carefully followed and that regulatory steps may be necessary Udgivelsesdato: 2008...

  4. Employment and breastfeeding outcomes in a sample of black women in the United States.

    Science.gov (United States)

    McCarter-Spaulding, Deborah; Lucas, Jennifer; Gore, Rebecca

    2011-12-01

    Black women have lower rates of breastfeeding initiation and duration than other racial groups have, but the effects of employment on breastfeeding, specifically for Black women, have not been studied extensively. The purpose of this research was to determine the influence of work or maternity leave on breastfeeding duration in a sample of Black women. Participants were recruited in the first postpartum week, and then followed monthly for six months or until complete weaning. The timing of returning to work significantly influenced the risk of weaning. Women who returned to work prior to 12 weeks were more likely to wean their babies than both those who returned to work after 12 weeks as well as those who remained at home. Policies that allow for at least 12 weeks' maternity leave would be likely to increase breastfeeding duration for employed Black women. Interdisciplinary research is needed to address health and economic issues of maternity leave and to eliminate racial disparities.

  5. Effective sample labeling

    International Nuclear Information System (INIS)

    Rieger, J.T.; Bryce, R.W.

    1990-01-01

    Ground-water samples collected for hazardous-waste and radiological monitoring have come under strict regulatory and quality assurance requirements as a result of laws such as the Resource Conservation and Recovery Act. To comply with these laws, the labeling system used to identify environmental samples had to be upgraded to ensure proper handling and to protect collection personnel from exposure to sample contaminants and sample preservatives. The sample label now used as the Pacific Northwest Laboratory is a complete sample document. In the event other paperwork on a labeled sample were lost, the necessary information could be found on the label

  6. Enhanced conformational sampling using enveloping distribution sampling.

    Science.gov (United States)

    Lin, Zhixiong; van Gunsteren, Wilfred F

    2013-10-14

    To lessen the problem of insufficient conformational sampling in biomolecular simulations is still a major challenge in computational biochemistry. In this article, an application of the method of enveloping distribution sampling (EDS) is proposed that addresses this challenge and its sampling efficiency is demonstrated in simulations of a hexa-β-peptide whose conformational equilibrium encompasses two different helical folds, i.e., a right-handed 2.7(10∕12)-helix and a left-handed 3(14)-helix, separated by a high energy barrier. Standard MD simulations of this peptide using the GROMOS 53A6 force field did not reach convergence of the free enthalpy difference between the two helices even after 500 ns of simulation time. The use of soft-core non-bonded interactions in the centre of the peptide did enhance the number of transitions between the helices, but at the same time led to neglect of relevant helical configurations. In the simulations of a two-state EDS reference Hamiltonian that envelops both the physical peptide and the soft-core peptide, sampling of the conformational space of the physical peptide ensures that physically relevant conformations can be visited, and sampling of the conformational space of the soft-core peptide helps to enhance the transitions between the two helices. The EDS simulations sampled many more transitions between the two helices and showed much faster convergence of the relative free enthalpy of the two helices compared with the standard MD simulations with only a slightly larger computational effort to determine optimized EDS parameters. Combined with various methods to smoothen the potential energy surface, the proposed EDS application will be a powerful technique to enhance the sampling efficiency in biomolecular simulations.

  7. Mindfulness training in a heterogeneous psychiatric sample : Outcome evaluation and comparison of different diagnostic groups

    NARCIS (Netherlands)

    Bos, Elisabeth H.; Merea, Ria; van den Brink, Erik; Sanderman, Robbert; Bartels-Velthuis, Agna A.

    ObjectivesTo examine outcome after mindfulness training in a heterogeneous psychiatric outpatient population and to compare outcome in different diagnostic groups. MethodOne hundred and forty-three patients in 5 diagnostic categories completed questionnaires about psychological symptoms, quality of

  8. Treatment outcome for a sample of patients with Class II division 1 malocclusion treated at a regional hospital orthodontic department.

    LENUS (Irish Health Repository)

    Burden, D J

    1998-01-01

    This retrospective study assessed the outcome of orthodontic treatment of 264 patients with Class II division 1 malocclusion (overjet greater than 6 mm). The sample comprised patients who had completed their fixed appliance orthodontic treatment at a regional hospital orthodontic unit in the Republic of Ireland. The PAR Index (Peer Assessment Rating) was used to evaluate treatment outcome using before and after treatment study casts. The results revealed that treatment for this particular type of malocclusion was highly effective with a very few patients failing to benefit from their orthodontic treatment.

  9. Sampling in practice

    DEFF Research Database (Denmark)

    Esbensen, Kim Harry; Petersen, Lars

    2005-01-01

    A basic knowledge of the Theory of Sampling (TOS) and a set of only eight sampling unit operations is all the practical sampler needs to ensure representativeness of samples extracted from all kinds of lots: production batches, - truckloads, - barrels, sub-division in the laboratory, sampling...... in nature and in the field (environmental sampling, forestry, geology, biology), from raw materials or manufactory processes etc. We here can only give a brief introduction to the Fundamental Sampling Principle (FSP) and these eight Sampling Unit Operations (SUO’s). Always respecting FSP and invoking only...... the necessary SUO’s (dependent on the practical situation) is the only prerequisite needed for eliminating all sampling bias and simultaneously minimizing sampling variance, and this is in addition a sure guarantee for making the final analytical results trustworthy. No reliable conclusions can be made unless...

  10. Sampling of ore

    International Nuclear Information System (INIS)

    Boehme, R.C.; Nicholas, B.L.

    1987-01-01

    This invention relates to a method of an apparatus for ore sampling. The method includes the steps of periodically removing a sample of the output material of a sorting machine, weighing each sample so that each is of the same weight, measuring a characteristic such as the radioactivity, magnetivity or the like of each sample, subjecting at least an equal portion of each sample to chemical analysis to determine the mineral content of the sample and comparing the characteristic measurement with desired mineral content of the chemically analysed portion of the sample to determine the characteristic/mineral ratio of the sample. The apparatus includes an ore sample collector, a deflector for deflecting a sample of ore particles from the output of an ore sorter into the collector and means for moving the deflector from a first position in which it is clear of the particle path from the sorter to a second position in which it is in the particle path at predetermined time intervals and for predetermined time periods to deflect the sample particles into the collector. The apparatus conveniently includes an ore crusher for comminuting the sample particle, a sample hopper means for weighing the hopper, a detector in the hopper for measuring a characteristic such as radioactivity, magnetivity or the like of particles in the hopper, a discharge outlet from the hopper and means for feeding the particles from the collector to the crusher and then to the hopper

  11. Pre-Pregnancy Dating Violence and Birth Outcomes Among Adolescent Mothers in a National Sample.

    Science.gov (United States)

    Madkour, Aubrey Spriggs; Xie, Yiqiong; Harville, Emily W

    2014-07-01

    Although infants born to adolescent mothers are at increased risk of adverse birth outcomes, little is known about contributors to birth outcomes in this group. Given past research linking partner abuse to adverse birth outcomes among adult mothers, we explored associations between pre-pregnancy verbal and physical dating violence and the birth weight and gestational age of infants born to adolescent mothers. Data from the National Longitudinal Study of Adolescent Health Waves I (1995/1996), II (1996), and IV (2007/2008) were analyzed. Girls whose first singleton live births occurred after Wave II interview and before age 20 (N = 558) self-reported infants' birth weight and gestational age at Wave IV. Dating violence victimization (verbal and physical) in the 18 months prior to Wave II interview was self-reported. Controls included Wave I age, parent education, age at pregnancy, time between reporting abuse and birth, and childhood physical and sexual abuse. Weighted multivariable regression models were performed separately by race (Black/non-Black).On average, births occurred 2 years after Wave II interview. Almost one in four mothers reported verbal dating violence victimization (23.6%), and 10.1% reported physical victimization. Birth weight and prevalence of verbal dating violence victimization were significantly lower in Black compared with non-Black teen mothers. In multivariable analyses, negative associations between physical dating abuse and birth outcomes became stronger as time increased for Black mothers. For example, pre-pregnancy physical dating abuse was associated with 0.79 kilograms lower birth weight (pdating abuse was unassociated with birth outcomes among non-Black mothers, and verbal abuse was unassociated with birth outcomes for all mothers. Reducing physical dating violence in adolescent relationships prior to pregnancy may improve Black adolescent mothers' birth outcomes. Intervening on long-term violence may be particularly important.

  12. Genetic Sample Inventory

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This database archives genetic tissue samples from marine mammals collected primarily from the U.S. east coast. The collection includes samples from field programs,...

  13. Superposition Enhanced Nested Sampling

    Directory of Open Access Journals (Sweden)

    Stefano Martiniani

    2014-08-01

    Full Text Available The theoretical analysis of many problems in physics, astronomy, and applied mathematics requires an efficient numerical exploration of multimodal parameter spaces that exhibit broken ergodicity. Monte Carlo methods are widely used to deal with these classes of problems, but such simulations suffer from a ubiquitous sampling problem: The probability of sampling a particular state is proportional to its entropic weight. Devising an algorithm capable of sampling efficiently the full phase space is a long-standing problem. Here, we report a new hybrid method for the exploration of multimodal parameter spaces exhibiting broken ergodicity. Superposition enhanced nested sampling combines the strengths of global optimization with the unbiased or athermal sampling of nested sampling, greatly enhancing its efficiency with no additional parameters. We report extensive tests of this new approach for atomic clusters that are known to have energy landscapes for which conventional sampling schemes suffer from broken ergodicity. We also introduce a novel parallelization algorithm for nested sampling.

  14. Chorionic villus sampling

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003406.htm Chorionic villus sampling To use the sharing features on this page, please enable JavaScript. Chorionic villus sampling (CVS) is a test some pregnant women have ...

  15. Sampling on Quasicrystals

    OpenAIRE

    Grepstad, Sigrid

    2011-01-01

    We prove that quasicrystals are universal sets of stable sampling in any dimension. Necessary and sufficient density conditions for stable sampling and interpolation sets in one dimension are studied in detail.

  16. Genetic Sample Inventory - NRDA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This database archives genetic tissue samples from marine mammals collected in the North-Central Gulf of Mexico from 2010-2015. The collection includes samples from...

  17. Test sample handling apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    A test sample handling apparatus using automatic scintillation counting for gamma detection, for use in such fields as radioimmunoassay, is described. The apparatus automatically and continuously counts large numbers of samples rapidly and efficiently by the simultaneous counting of two samples. By means of sequential ordering of non-sequential counting data, it is possible to obtain precisely ordered data while utilizing sample carrier holders having a minimum length. (U.K.)

  18. Laboratory Sampling Guide

    Science.gov (United States)

    2012-05-11

    environment, and by ingestion of foodstuffs that have incorporated C-14 by photosynthesis . Like tritium, C-14 is a very low energy beta emitter and is... bacterial growth and to minimize development of solids in the sample. • Properly identify each sample container with name, SSN, and collection start and...sampling in the same cardboard carton. The sample may be kept cool or frozen during collection to control odor and bacterial growth. • Once

  19. High speed network sampling

    OpenAIRE

    Rindalsholt, Ole Arild

    2005-01-01

    Master i nettverks- og systemadministrasjon Classical Sampling methods play an important role in the current practice of Internet measurement. With today’s high speed networks, routers cannot manage to generate complete Netflow data for every packet. They have to perform restricted sampling. This thesis summarizes some of the most important sampling schemes and their applications before diving into an analysis on the effect of sampling Netflow records.

  20. Association between duration of untreated bipolar disorder and clinical outcome: data from a Brazilian sample

    Directory of Open Access Journals (Sweden)

    Gustavo C. Medeiros

    2016-03-01

    Full Text Available Objective: Bipolar disorder (BD is often left untreated for long periods, and this delay in treatment correlates with unfavorable prognosis. The present study sought to assess the magnitude of duration of untreated bipolar disorder (DUB in Brazil. We hypothesized that DUB would be longer in Brazil than in developed countries, and would be associated with poor clinical outcomes. Methods: One hundred and fifty-two psychiatric outpatients were evaluated for BD diagnosis, demographics, DUB, and clinical outcomes. Results: The mean age and mean DUB were, respectively, 38.9±10.8 and 10.4±9.8 years. An extended DUB was associated with early onset of BD (p < 0.001, depression as first mood episode (p = 0.04, and presence of BD in a first-degree relative (p = 0.012. Additionally, a longer DUB was associated with poorer clinical outcomes, such as elevated rates of rapid cycling (p = 0.004 and anxiety disorders (p = 0.016, as well as lower levels of current full remission (p = 0.021. Conclusion: As DUB may be a modifiable variable, better medical education regarding mental health, more structured medical services, and population-wide psychoeducation might reduce the time between onset and proper management of BD, thus improving outcome.

  1. Early School Outcomes for Children of Postpartum Depressed Mothers: Comparison with a Community Sample

    Science.gov (United States)

    Kersten-Alvarez, Laura E.; Hosman, Clemens M. H.; Riksen-Walraven, J. Marianne; van Doesum, Karin T. M.; Smeekens, Sanny; Hoefnagels, Cees

    2012-01-01

    Previous studies of the long-term effects of maternal postpartum depression (PPD) on child development have mostly focused on a limited set of outcomes, and have often not controlled for risk factors associated with maternal depression. The present study compared children of postpartum depressed mothers (n = 29) with children from a community…

  2. Course and Short-Term Outcomes of Separation Anxiety Disorder in a Community Sample of Twins.

    Science.gov (United States)

    Foley, Debra L.; Pickles, Andrew; Maes, Hermine M.; Silberg, Judy L.; Eaves, Lindon J.

    2004-01-01

    Objective: To assess the course and short-term outcomes associated with separation anxiety disorder (SAD) in a community setting. Method: The subjects were 161 of 2,061 8- to 17-year-old twins with SAD from a community-based twin study. Subjects were born between 1974 and 1983. Subjects and parents were personally interviewed about the subject's…

  3. Mars Sample Handling Functionality

    Science.gov (United States)

    Meyer, M. A.; Mattingly, R. L.

    2018-04-01

    The final leg of a Mars Sample Return campaign would be an entity that we have referred to as Mars Returned Sample Handling (MRSH.) This talk will address our current view of the functional requirements on MRSH, focused on the Sample Receiving Facility (SRF).

  4. IAEA Sampling Plan

    Energy Technology Data Exchange (ETDEWEB)

    Geist, William H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-15

    The objectives for this presentation are to describe the method that the IAEA uses to determine a sampling plan for nuclear material measurements; describe the terms detection probability and significant quantity; list the three nuclear materials measurement types; describe the sampling method applied to an item facility; and describe multiple method sampling.

  5. Developing Water Sampling Standards

    Science.gov (United States)

    Environmental Science and Technology, 1974

    1974-01-01

    Participants in the D-19 symposium on aquatic sampling and measurement for water pollution assessment were informed that determining the extent of waste water stream pollution is not a cut and dry procedure. Topics discussed include field sampling, representative sampling from storm sewers, suggested sampler features and application of improved…

  6. Patient activation and disparate health care outcomes in a racially diverse sample of chronically ill older adults.

    Science.gov (United States)

    Ryvicker, Miriam; Peng, Timothy R; Feldman, Penny Hollander

    2012-11-01

    The Patient Activation Measure (PAM) assesses people's ability to self-manage their health. Variations in PAM score have been linked with health behaviors, outcomes, and potential disparities. This study assessed the relative impacts of activation, socio-demographic and clinical factors on health care outcomes in a racially diverse sample of chronically ill, elderly homecare patients. Using survey and administrative data from 249 predominantly non-White patients, logistic regression was conducted to examine the effects of activation level and patient characteristics on the likelihood of subsequent hospitalization and emergency department (ED) use. Activation was not a significant predictor of hospitalization or ED use in adjusted models. Non-Whites were more likely than Whites to have a hospitalization or ED visit. Obesity was a strong predictor of both outcomes. Further research should examine potential sources of disadvantage among chronically ill homecare patients to design effective interventions to reduce health disparities in this population.

  7. Occurrence of multiple mental health or substance use outcomes among bisexuals: a respondent-driven sampling study

    Directory of Open Access Journals (Sweden)

    Greta R. Bauer

    2016-06-01

    Full Text Available Abstract Background Bisexual populations have higher prevalence of depression, anxiety, suicidality and substance use than heterosexuals, and often than gay men or lesbians. The co-occurrence of multiple outcomes has rarely been studied. Methods Data were collected from 405 bisexuals using respondent-driven sampling. Weighted analyses were conducted for 387 with outcome data. Multiple outcomes were defined as 3 or more of: depression, anxiety, suicide ideation, problematic alcohol use, or polysubstance use. Results Among bisexuals, 19.0 % had multiple outcomes. We did not find variation in raw frequency of multiple outcomes across sociodemographic variables (e.g. gender, age. After adjustment, gender and sexual orientation identity were associated, with transgender women and those identifying as bisexual only more likely to have multiple outcomes. Social equity factors had a strong impact in both crude and adjusted analysis: controlling for other factors, high mental health/substance use burden was associated with greater discrimination (prevalence risk ratio (PRR = 5.71; 95 % CI: 2.08, 15.63 and lower education (PRR = 2.41; 95 % CI: 1.06, 5.49, while higher income-to-needs ratio was protective (PRR = 0.44; 0.20, 1.00. Conclusions Mental health and substance use outcomes with high prevalence among bisexuals frequently co-occurred. We find some support for the theory that these multiple outcomes represent a syndemic, defined as co-occurring and mutually reinforcing adverse outcomes driven by social inequity.

  8. Loss of control eating and weight outcomes after bariatric surgery: a study with a Portuguese sample

    OpenAIRE

    Conceição, Eva Martins; Silva, Ana Isabel Pinto Bastos Leite; Brandão, Isabel; Vaz, Ana Rita Rendeiro Ribeiro; Ramalho, Sofia Marlene Marques; Arrojado, Filipa; Costa, José; Machado, Paulo P. P.

    2014-01-01

    The present study aim is to investigate the frequency of loss of control eating (LOC) episodes in three groups with different assessment times: one before, one at short and one at long-term after bariatric surgery; as well as to explore the association of postoperative problematic eating behaviors and weight outcomes and psychological characteristics. This cross-sectional study compared a group of preoperative bariatric surgery patients (n = 176) and two postoperative groups, one at short-ter...

  9. Generalized sampling in Julia

    DEFF Research Database (Denmark)

    Jacobsen, Christian Robert Dahl; Nielsen, Morten; Rasmussen, Morten Grud

    2017-01-01

    Generalized sampling is a numerically stable framework for obtaining reconstructions of signals in different bases and frames from their samples. For example, one can use wavelet bases for reconstruction given frequency measurements. In this paper, we will introduce a carefully documented toolbox...... for performing generalized sampling in Julia. Julia is a new language for technical computing with focus on performance, which is ideally suited to handle the large size problems often encountered in generalized sampling. The toolbox provides specialized solutions for the setup of Fourier bases and wavelets....... The performance of the toolbox is compared to existing implementations of generalized sampling in MATLAB....

  10. The Lunar Sample Compendium

    Science.gov (United States)

    Meyer, Charles

    2009-01-01

    The Lunar Sample Compendium is a succinct summary of the data obtained from 40 years of study of Apollo and Luna samples of the Moon. Basic petrographic, chemical and age information is compiled, sample-by-sample, in the form of an advanced catalog in order to provide a basic description of each sample. The LSC can be found online using Google. The initial allocation of lunar samples was done sparingly, because it was realized that scientific techniques would improve over the years and new questions would be formulated. The LSC is important because it enables scientists to select samples within the context of the work that has already been done and facilitates better review of proposed allocations. It also provides back up material for public displays, captures information found only in abstracts, grey literature and curatorial databases and serves as a ready access to the now-vast scientific literature.

  11. Image Sampling with Quasicrystals

    Directory of Open Access Journals (Sweden)

    Mark Grundland

    2009-07-01

    Full Text Available We investigate the use of quasicrystals in image sampling. Quasicrystals produce space-filling, non-periodic point sets that are uniformly discrete and relatively dense, thereby ensuring the sample sites are evenly spread out throughout the sampled image. Their self-similar structure can be attractive for creating sampling patterns endowed with a decorative symmetry. We present a brief general overview of the algebraic theory of cut-and-project quasicrystals based on the geometry of the golden ratio. To assess the practical utility of quasicrystal sampling, we evaluate the visual effects of a variety of non-adaptive image sampling strategies on photorealistic image reconstruction and non-photorealistic image rendering used in multiresolution image representations. For computer visualization of point sets used in image sampling, we introduce a mosaic rendering technique.

  12. 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.

  13. 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.

  14. Personality Pathology Predicts Outcomes in a Treatment-Seeking Sample with Bipolar I Disorder

    Directory of Open Access Journals (Sweden)

    Susan J. Wenze

    2014-01-01

    Full Text Available We conducted a secondary analysis of data from a clinical trial to explore the relationship between degree of personality disorder (PD pathology (i.e., number of subthreshold and threshold PD symptoms and mood and functioning outcomes in Bipolar I Disorder (BD-I. Ninety-two participants completed baseline mood and functioning assessments and then underwent 4 months of treatment for an index manic, mixed, or depressed phase acute episode. Additional assessments occurred over a 28-month follow-up period. PD pathology did not predict psychosocial functioning or manic symptoms at 4 or 28 months. However, it did predict depressive symptoms at both timepoints, as well as percent time symptomatic. Clusters A and C pathology were most strongly associated with depression. Our findings fit with the literature highlighting the negative repercussions of PD pathology on a range of outcomes in mood disorders. This study builds upon previous research, which has largely focused on major depression and which has primarily taken a categorical approach to examining PD pathology in BD.

  15. Obstetric and Psychiatric Outcomes in a Sample of Saudi Teen-Aged Mothers

    Directory of Open Access Journals (Sweden)

    Magdy H Balaha

    2009-08-01

    Full Text Available AIM: To assess the prevalence of adverse obstetric and psychiatric outcomes among primigravid teenagers compared to adult women in Al-Ahsa, Saudi Arabia, if given equal antenatal care. METHODS: In this comparative study, 168 cases aged 16.6-19.8 years were compared to 632 cases aged 20-29 years. Data collection was done over a six month period in 2007-08. Demographic, antenatal, intranatal and postnatal obstetric events besides the postnatal psychiatric evaluation were done and analyzed using routine statistical tests with significance at P<0.05. Also risk quantification was done using the odds ratio. RESULTS: Antenatal morbidities (e.g. pregnancy induced hypertension, gestational diabetes, anemia, antepartum hemorrhage did not differ between the two groups. Also, the two groups showed no significant difference regarding cesarean section, low birth weight, preterm delivery and neonatal admission to intensive care units. Prevalence of psychiatric disorders was similar in both groups. The anxiety disorders were significantly higher in the younger age group due to increased prevalence for the post traumatic stress disorder and generalized anxiety disorder. CONCLUSION: Teenage pregnancy receiving adequate antenatal care and ending in live births is not associated with significant adverse obstetric outcomes or major psychopathology in Al Ahsa, Saudi Arabia. [TAF Prev Med Bull 2009; 8(4.000: 285-290

  16. Sample size methodology

    CERN Document Server

    Desu, M M

    2012-01-01

    One of the most important problems in designing an experiment or a survey is sample size determination and this book presents the currently available methodology. It includes both random sampling from standard probability distributions and from finite populations. Also discussed is sample size determination for estimating parameters in a Bayesian setting by considering the posterior distribution of the parameter and specifying the necessary requirements. The determination of the sample size is considered for ranking and selection problems as well as for the design of clinical trials. Appropria

  17. Statistical sampling strategies

    International Nuclear Information System (INIS)

    Andres, T.H.

    1987-01-01

    Systems assessment codes use mathematical models to simulate natural and engineered systems. Probabilistic systems assessment codes carry out multiple simulations to reveal the uncertainty in values of output variables due to uncertainty in the values of the model parameters. In this paper, methods are described for sampling sets of parameter values to be used in a probabilistic systems assessment code. Three Monte Carlo parameter selection methods are discussed: simple random sampling, Latin hypercube sampling, and sampling using two-level orthogonal arrays. Three post-selection transformations are also described: truncation, importance transformation, and discretization. Advantages and disadvantages of each method are summarized

  18. Statistical distribution sampling

    Science.gov (United States)

    Johnson, E. S.

    1975-01-01

    Determining the distribution of statistics by sampling was investigated. Characteristic functions, the quadratic regression problem, and the differential equations for the characteristic functions are analyzed.

  19. Irritability Trajectories, Cortical Thickness, and Clinical Outcomes in a Sample Enriched for Preschool Depression.

    Science.gov (United States)

    Pagliaccio, David; Pine, Daniel S; Barch, Deanna M; Luby, Joan L; Leibenluft, Ellen

    2018-05-01

    Cross-sectional, longitudinal, and genetic associations exist between irritability and depression. Prior studies have examined developmental trajectories of irritability, clinical outcomes, and associations with child and familial depression. However, studies have not integrated neurobiological measures. The present study examined developmental trajectories of irritability, clinical outcomes, and cortical structure among preschoolers oversampled for depressive symptoms. Beginning at 3 to 5 years old, a sample of 271 children enriched for early depressive symptoms were assessed longitudinally by clinical interview. Latent class mixture models identified trajectories of irritability severity. Risk factors, clinical outcomes, and cortical thickness were compared across trajectory classes. Cortical thickness measures were extracted from 3 waves of magnetic resonance imaging at 7 to 12 years of age. Three trajectory classes were identified among these youth: 53.50% of children exhibited elevated irritability during preschool that decreased longitudinally, 30.26% exhibited consistently low irritability, and 16.24% exhibited consistently elevated irritability. Compared with other classes, the elevated irritability class exhibited higher rates of maternal depression, early life adversity, later psychiatric diagnoses, and functional impairment. Further, elevated baseline irritability predicted later depression beyond adversity and personal and maternal depression history. The elevated irritability class exhibited a thicker cortex in the left superior frontal and temporal gyri and the right inferior parietal lobule. Irritability manifested with specific developmental trajectories in this sample enriched for early depression. Persistently elevated irritability predicted poor psychiatric outcomes, higher risk for later depression, and decreased overall function later in development. Greater frontal, temporal, and parietal cortical thickness also was found, providing neural

  20. Attention Deficit Hyperactivity Disorder Symptoms, Comorbidities, Substance Use, and Social Outcomes among Men and Women in a Canadian Sample

    Directory of Open Access Journals (Sweden)

    Evelyn Vingilis

    2015-01-01

    Full Text Available Background. Attention deficit hyperactivity disorder (ADHD is a neurodevelopmental disorder that can persist in adolescence and adulthood. Aim. To examine prevalence of ADHD symptoms and correlates in a representative sample of adults 18 years and older living in Ontario, Canada. Method. We used the Centre for Addiction and Mental Health Monitor, an ongoing cross-sectional telephone survey, to examine the relationships between ADHD positive symptoms and comorbidities, substance use, medication use, social outcomes, and sociodemographics. Results. Of 4014 residents sampled in 2011-2012, 3.30% (2.75%–3.85% screened positively for ADHD symptoms (women = 3.6%; men = 3.0%. For men, distress, antisocial symptoms, cocaine use, antianxiety medication use, antidepressant medication use, and criminal offence arrest were associated with positive ADHD screen. For women, distress, cocaine use, antianxiety medication use, antidepressant medication use, pain medication use, and motor vehicle collision in the past year were associated with positive ADHD screen. Conclusions. ADHD symptoms are associated with adverse medical and social outcomes that are in some cases gender specific.

  1. Big Data, Small Sample.

    Science.gov (United States)

    Gerlovina, Inna; van der Laan, Mark J; Hubbard, Alan

    2017-05-20

    Multiple comparisons and small sample size, common characteristics of many types of "Big Data" including those that are produced by genomic studies, present specific challenges that affect reliability of inference. Use of multiple testing procedures necessitates calculation of very small tail probabilities of a test statistic distribution. Results based on large deviation theory provide a formal condition that is necessary to guarantee error rate control given practical sample sizes, linking the number of tests and the sample size; this condition, however, is rarely satisfied. Using methods that are based on Edgeworth expansions (relying especially on the work of Peter Hall), we explore the impact of departures of sampling distributions from typical assumptions on actual error rates. Our investigation illustrates how far the actual error rates can be from the declared nominal levels, suggesting potentially wide-spread problems with error rate control, specifically excessive false positives. This is an important factor that contributes to "reproducibility crisis". We also review some other commonly used methods (such as permutation and methods based on finite sampling inequalities) in their application to multiple testing/small sample data. We point out that Edgeworth expansions, providing higher order approximations to the sampling distribution, offer a promising direction for data analysis that could improve reliability of studies relying on large numbers of comparisons with modest sample sizes.

  2. Sampling system and method

    Science.gov (United States)

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

    2013-04-16

    The present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit.

  3. Simple street tree sampling

    Science.gov (United States)

    David J. Nowak; Jeffrey T. Walton; James Baldwin; Jerry. Bond

    2015-01-01

    Information on street trees is critical for management of this important resource. Sampling of street tree populations provides an efficient means to obtain street tree population information. Long-term repeat measures of street tree samples supply additional information on street tree changes and can be used to report damages from catastrophic events. Analyses of...

  4. Sampling or gambling

    Energy Technology Data Exchange (ETDEWEB)

    Gy, P.M.

    1981-12-01

    Sampling can be compared to no other technique. A mechanical sampler must above all be selected according to its aptitude for supressing or reducing all components of the sampling error. Sampling is said to be correct when it gives all elements making up the batch of matter submitted to sampling an uniform probability of being selected. A sampler must be correctly designed, built, installed, operated and maintained. When the conditions of sampling correctness are not strictly respected, the sampling error can no longer be controlled and can, unknown to the user, be unacceptably large: the sample is no longer representative. The implementation of an incorrect sampler is a form of gambling and this paper intends to show that at this game the user is nearly always the loser in the long run. The users' and the manufacturers' interests may diverge and the standards which should safeguard the users' interests very often fail to do so by tolerating or even recommending incorrect techniques such as the implementation of too narrow cutters traveling too fast through the stream to be sampled.

  5. Sample pretretment in microsystems

    DEFF Research Database (Denmark)

    Perch-Nielsen, Ivan R.

    2003-01-01

    : Sample preparation → DNA amplification → DNA analysis. The overall goal of the project is integration of as many as possible of these steps. This thesis covers mainly pretreatment in a microchip. Some methods for sample pretreatment have been tested. Most conventional is fluorescence activated cell sort......When a sample, e.g. from a patient, is processed using conventional methods, the sample must be transported to the laboratory where it is analyzed, after which the results is sent back. By integrating the separate steps of the analysis in a micro total analysis system (μTAS), results can...... be obtained fast and better. Preferably with all the processes from sample to signal moved to the bedside of the patient. Of course there is still much to learn and study in the process of miniaturization. DNA analysis is one process subject to integration. There are roughly three steps in a DNA analysis...

  6. Biological sample collector

    Science.gov (United States)

    Murphy, Gloria A [French Camp, CA

    2010-09-07

    A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

  7. Associations between ADHD symptoms and smoking outcome expectancies in a non-clinical sample of daily cigarette smokers.

    Science.gov (United States)

    Goldenson, Nicholas I; Pang, Raina D; Leventhal, Adam M

    2016-03-01

    Smoking outcome expectancies for positive reinforcement (PR: beliefs that smoking produces desirable outcomes) and negative reinforcement (NR: beliefs that smoking alleviates negative affect) are modifiable cognitive manifestations of affect-mediated smoking motivation. Based on prior data and theory, we hypothesized that NR and PR expectancies are associated with ADHD symptom levels in a non-clinical sample of cigarette smokers. (Am J Addict 2016; XX:XX -XX) METHODS: Daily cigarette smokers (N = 256) completed self-report measures of ADHD symptoms and smoking outcome expectancies. Cross-sectional associations of overall ADHD symptomatology and the ADHD symptom dimensions of inattention (IN: difficulty concentrating and distractibility) and hyperactivity impulsivity (HI: poor inhibitory control and motor activity restlessness) with PR and NR smoking outcome expectancies were examined. Higher levels of overall, IN and HI ADHD symptoms were positively associated with NR smoking expectancies after statistically controlling for anxiety, depression, alcohol/drug use problems, nicotine dependence, and other smoking expectancies. Although neither HI nor IN symptom dimensions exhibited empirically unique relations to NR expectancies over and above one another, the collective variance across IN and HI was associated with NR expectancies. PR expectancies were not associated with ADHD symptoms. Although PR and NR expectancies may be important etiological influences in the overall population of smokers, NR outcome expectancies appear to be disproportionately expressed in smokers with elevated ADHD symptoms. Cognitive manifestations of NR motivation, which may be modifiable via intervention, are prominent in smokers with elevated ADHD symptoms. Beliefs that smoking alleviates negative affect may underlie ADHD-smoking comorbidity. © American Academy of Addiction Psychiatry.

  8. PFP Wastewater Sampling Facility

    International Nuclear Information System (INIS)

    Hirzel, D.R.

    1995-01-01

    This test report documents the results obtained while conducting operational testing of the sampling equipment in the 225-WC building, the PFP Wastewater Sampling Facility. The Wastewater Sampling Facility houses equipment to sample and monitor the PFP's liquid effluents before discharging the stream to the 200 Area Treated Effluent Disposal Facility (TEDF). The majority of the streams are not radioactive and discharges from the PFP Heating, Ventilation, and Air Conditioning (HVAC). The streams that might be contaminated are processed through the Low Level Waste Treatment Facility (LLWTF) before discharging to TEDF. The sampling equipment consists of two flow-proportional composite samplers, an ultrasonic flowmeter, pH and conductivity monitors, chart recorder, and associated relays and current isolators to interconnect the equipment to allow proper operation. Data signals from the monitors are received in the 234-5Z Shift Office which contains a chart recorder and alarm annunciator panel. The data signals are also duplicated and sent to the TEDF control room through the Local Control Unit (LCU). Performing the OTP has verified the operability of the PFP wastewater sampling system. This Operability Test Report documents the acceptance of the sampling system for use

  9. Contributions to sampling statistics

    CERN Document Server

    Conti, Pier; Ranalli, Maria

    2014-01-01

    This book contains a selection of the papers presented at the ITACOSM 2013 Conference, held in Milan in June 2013. ITACOSM is the bi-annual meeting of the Survey Sampling Group S2G of the Italian Statistical Society, intended as an international  forum of scientific discussion on the developments of theory and application of survey sampling methodologies and applications in human and natural sciences. The book gathers research papers carefully selected from both invited and contributed sessions of the conference. The whole book appears to be a relevant contribution to various key aspects of sampling methodology and techniques; it deals with some hot topics in sampling theory, such as calibration, quantile-regression and multiple frame surveys, and with innovative methodologies in important topics of both sampling theory and applications. Contributions cut across current sampling methodologies such as interval estimation for complex samples, randomized responses, bootstrap, weighting, modeling, imputati...

  10. Waste classification sampling plan

    International Nuclear Information System (INIS)

    Landsman, S.D.

    1998-01-01

    The purpose of this sampling is to explain the method used to collect and analyze data necessary to verify and/or determine the radionuclide content of the B-Cell decontamination and decommissioning waste stream so that the correct waste classification for the waste stream can be made, and to collect samples for studies of decontamination methods that could be used to remove fixed contamination present on the waste. The scope of this plan is to establish the technical basis for collecting samples and compiling quantitative data on the radioactive constituents present in waste generated during deactivation activities in B-Cell. Sampling and radioisotopic analysis will be performed on the fixed layers of contamination present on structural material and internal surfaces of process piping and tanks. In addition, dose rate measurements on existing waste material will be performed to determine the fraction of dose rate attributable to both removable and fixed contamination. Samples will also be collected to support studies of decontamination methods that are effective in removing the fixed contamination present on the waste. Sampling performed under this plan will meet criteria established in BNF-2596, Data Quality Objectives for the B-Cell Waste Stream Classification Sampling, J. M. Barnett, May 1998

  11. Sample Return Robot

    Data.gov (United States)

    National Aeronautics and Space Administration — This Challenge requires demonstration of an autonomous robotic system to locate and collect a set of specific sample types from a large planetary analog area and...

  12. Ecotoxicology statistical sampling

    International Nuclear Information System (INIS)

    Saona, G.

    2012-01-01

    This presentation introduces to general concepts in toxicology sample designs such as the distribution of organic or inorganic contaminants, a microbiological contamination, and the determination of the position in an eco toxicological bioassays ecosystem.

  13. Mini MAX - Medicaid Sample

    Data.gov (United States)

    U.S. Department of Health & Human Services — To facilitate wider use of MAX, CMS contracted with Mathematica to convene a technical expert panel (TEP) and determine the feasibility of creating a sample file for...

  14. Operational air sampling report

    International Nuclear Information System (INIS)

    Lyons, C.L.

    1994-03-01

    Nevada Test Site vertical shaft and tunnel events generate beta/gamma fission products. The REECo air sampling program is designed to measure these radionuclides at various facilities supporting these events. The current testing moratorium and closure of the Decontamination Facility has decreased the scope of the program significantly. Of the 118 air samples collected in the only active tunnel complex, only one showed any airborne fission products. Tritiated water vapor concentrations were very similar to previously reported levels. The 206 air samples collected at the Area-6 decontamination bays and laundry were again well below any Derived Air Concentration calculation standard. Laboratory analyses of these samples were negative for any airborne fission products

  15. Collecting Samples for Testing

    Science.gov (United States)

    ... Creatinine Ratio Valproic Acid Vancomycin Vanillylmandelic Acid (VMA) VAP Vitamin A Vitamin B12 and Folate Vitamin D ... that used for CSF in that they require aspiration of a sample of the fluid through a ...

  16. Roadway sampling evaluation.

    Science.gov (United States)

    2014-09-01

    The Florida Department of Transportation (FDOT) has traditionally required that all sampling : and testing of asphalt mixtures be at the Contractors production facility. With recent staffing cuts, as : well as budget reductions, FDOT has been cons...

  17. Soil Gas Sampling

    Science.gov (United States)

    Field Branches Quality System and Technical Procedures: This document describes general and specific procedures, methods and considerations to be used and observed when collecting soil gas samples for field screening or laboratory analysis.

  18. Soil Sampling Operating Procedure

    Science.gov (United States)

    EPA Region 4 Science and Ecosystem Support Division (SESD) document that describes general and specific procedures, methods, and considerations when collecting soil samples for field screening or laboratory analysis.

  19. Statistical sampling plans

    International Nuclear Information System (INIS)

    Jaech, J.L.

    1984-01-01

    In auditing and in inspection, one selects a number of items by some set of procedures and performs measurements which are compared with the operator's values. This session considers the problem of how to select the samples to be measured, and what kinds of measurements to make. In the inspection situation, the ultimate aim is to independently verify the operator's material balance. The effectiveness of the sample plan in achieving this objective is briefly considered. The discussion focuses on the model plant

  20. Two phase sampling

    CERN Document Server

    Ahmad, Zahoor; Hanif, Muhammad

    2013-01-01

    The development of estimators of population parameters based on two-phase sampling schemes has seen a dramatic increase in the past decade. Various authors have developed estimators of population using either one or two auxiliary variables. The present volume is a comprehensive collection of estimators available in single and two phase sampling. The book covers estimators which utilize information on single, two and multiple auxiliary variables of both quantitative and qualitative nature. Th...

  1. Uranium tailings sampling manual

    International Nuclear Information System (INIS)

    Feenstra, S.; Reades, D.W.; Cherry, J.A.; Chambers, D.B.; Case, G.G.; Ibbotson, B.G.

    1985-01-01

    The purpose of this manual is to describe the requisite sampling procedures for the application of uniform high-quality standards to detailed geotechnical, hydrogeological, geochemical and air quality measurements at Canadian uranium tailings disposal sites. The selection and implementation of applicable sampling procedures for such measurements at uranium tailings disposal sites are complicated by two primary factors. Firstly, the physical and chemical nature of uranium mine tailings and effluent is considerably different from natural soil materials and natural waters. Consequently, many conventional methods for the collection and analysis of natural soils and waters are not directly applicable to tailings. Secondly, there is a wide range in the physical and chemical nature of uranium tailings. The composition of the ore, the milling process, the nature of tailings depositon, and effluent treatment vary considerably and are highly site-specific. Therefore, the definition and implementation of sampling programs for uranium tailings disposal sites require considerable evaluation, and often innovation, to ensure that appropriate sampling and analysis methods are used which provide the flexibility to take into account site-specific considerations. The following chapters describe the objective and scope of a sampling program, preliminary data collection, and the procedures for sampling of tailings solids, surface water and seepage, tailings pore-water, and wind-blown dust and radon

  2. Reactor water sampling device

    International Nuclear Information System (INIS)

    Sakamaki, Kazuo.

    1992-01-01

    The present invention concerns a reactor water sampling device for sampling reactor water in an in-core monitor (neutron measuring tube) housing in a BWR type reactor. The upper end portion of a drain pipe of the reactor water sampling device is attached detachably to an in-core monitor flange. A push-up rod is inserted in the drain pipe vertically movably. A sampling vessel and a vacuum pump are connected to the lower end of the drain pipe. A vacuum pump is operated to depressurize the inside of the device and move the push-up rod upwardly. Reactor water in the in-core monitor housing flows between the drain pipe and the push-up rod and flows into the sampling vessel. With such a constitution, reactor water in the in-core monitor housing can be sampled rapidly with neither opening the lid of the reactor pressure vessel nor being in contact with air. Accordingly, operator's exposure dose can be reduced. (I.N.)

  3. Wet gas sampling

    Energy Technology Data Exchange (ETDEWEB)

    Welker, T.F.

    1997-07-01

    The quality of gas has changed drastically in the past few years. Most gas is wet with hydrocarbons, water, and heavier contaminants that tend to condense if not handled properly. If a gas stream is contaminated with condensables, the sampling of that stream must be done in a manner that will ensure all of the components in the stream are introduced into the sample container as the composite. The sampling and handling of wet gas is extremely difficult under ideal conditions. There are no ideal conditions in the real world. The problems related to offshore operations and other wet gas systems, as well as the transportation of the sample, are additional problems that must be overcome if the analysis is to mean anything to the producer and gatherer. The sampling of wet gas systems is decidedly more difficult than sampling conventional dry gas systems. Wet gas systems were generally going to result in the measurement of one heating value at the inlet of the pipe and a drastic reduction in the heating value of the gas at the outlet end of the system. This is caused by the fallout or accumulation of the heavier products that, at the inlet, may be in the vapor state in the pipeline; hence, the high gravity and high BTU. But, in fact, because of pressure and temperature variances, these liquids condense and form a liquid that is actually running down the pipe as a stream or is accumulated in drips to be blown from the system. (author)

  4. Lunar Sample Compendium

    Science.gov (United States)

    Meyer, Charles

    2005-01-01

    The purpose of the Lunar Sample Compendium will be to inform scientists, astronauts and the public about the various lunar samples that have been returned from the Moon. This Compendium will be organized rock by rock in the manor of a catalog, but will not be as comprehensive, nor as complete, as the various lunar sample catalogs that are available. Likewise, this Compendium will not duplicate the various excellent books and reviews on the subject of lunar samples (Cadogen 1981, Heiken et al. 1991, Papike et al. 1998, Warren 2003, Eugster 2003). However, it is thought that an online Compendium, such as this, will prove useful to scientists proposing to study individual lunar samples and should help provide backup information for lunar sample displays. This Compendium will allow easy access to the scientific literature by briefly summarizing the significant findings of each rock along with the documentation of where the detailed scientific data are to be found. In general, discussion and interpretation of the results is left to the formal reviews found in the scientific literature. An advantage of this Compendium will be that it can be updated, expanded and corrected as need be.

  5. Effects of depression, anxiety, self-esteem, and health behaviour on neonatal outcomes in a population-based Hungarian sample.

    Science.gov (United States)

    Bödecs, Tamás; Horváth, Boldizsár; Szilágyi, Eniko; Gonda, Xénia; Rihmer, Zoltán; Sándor, János

    2011-01-01

    To investigate possible associations of maternal antenatal depression, anxiety and self-esteem with negative neonatal outcomes controlling for the effects of demographic covariates and health behaviour in a Hungarian sample. A population-based monitoring system was established in 10 districts of health visitors in Szombathely, Hungary, covering every woman registered as pregnant between February 1, 2008 and February 1 2009. Three hundred and seven expectant women in the early stage of their pregnancy were surveyed using the Short Form of Beck Depression Inventory for the measurement of depression and the Spielberger Trait-Anxiety Inventory for the measurement of anxiety. Self-esteem was evaluated by the Rosenberg's Self-Esteem Scale. At the end of the follow-up period, data on 261 mothers and their singleton neonates were available. The relationship between the explanatory and outcome variables (birth weight, length, chest circumference, gestational age, and 1- and 5-min Apgar score) was tested in girls and boys separately by multiple linear regression analysis (Forward method). Categorical variables were used as "dummy variables". Maternal depression, anxiety and health behaviour did not show any association with neonatal outcomes. Higher level of maternal self-esteem was associated with higher birth weight and birth length in boys and higher birth length in girls. Maternal education positively correlated with birth length, gestational age and chest circumference in boys, and with birth length in girls. In girls, maternal socioeconomic status showed a positive association with birth weight and gestational age, while common law marriage had a negative effect on birth weight and chest circumference. Lower level of maternal self-esteem possibly leads to a higher level of maternal stress which may reduce fetal growth via physiologic changes. Gender differences in associations between demographic factors and neonatal outcome measures indicate differences in fetal

  6. Nonuniform sampling by quantiles

    Science.gov (United States)

    Craft, D. Levi; Sonstrom, Reilly E.; Rovnyak, Virginia G.; Rovnyak, David

    2018-03-01

    A flexible strategy for choosing samples nonuniformly from a Nyquist grid using the concept of statistical quantiles is presented for broad classes of NMR experimentation. Quantile-directed scheduling is intuitive and flexible for any weighting function, promotes reproducibility and seed independence, and is generalizable to multiple dimensions. In brief, weighting functions are divided into regions of equal probability, which define the samples to be acquired. Quantile scheduling therefore achieves close adherence to a probability distribution function, thereby minimizing gaps for any given degree of subsampling of the Nyquist grid. A characteristic of quantile scheduling is that one-dimensional, weighted NUS schedules are deterministic, however higher dimensional schedules are similar within a user-specified jittering parameter. To develop unweighted sampling, we investigated the minimum jitter needed to disrupt subharmonic tracts, and show that this criterion can be met in many cases by jittering within 25-50% of the subharmonic gap. For nD-NUS, three supplemental components to choosing samples by quantiles are proposed in this work: (i) forcing the corner samples to ensure sampling to specified maximum values in indirect evolution times, (ii) providing an option to triangular backfill sampling schedules to promote dense/uniform tracts at the beginning of signal evolution periods, and (iii) providing an option to force the edges of nD-NUS schedules to be identical to the 1D quantiles. Quantile-directed scheduling meets the diverse needs of current NUS experimentation, but can also be used for future NUS implementations such as off-grid NUS and more. A computer program implementing these principles (a.k.a. QSched) in 1D- and 2D-NUS is available under the general public license.

  7. AND/OR Importance Sampling

    OpenAIRE

    Gogate, Vibhav; Dechter, Rina

    2012-01-01

    The paper introduces AND/OR importance sampling for probabilistic graphical models. In contrast to importance sampling, AND/OR importance sampling caches samples in the AND/OR space and then extracts a new sample mean from the stored samples. We prove that AND/OR importance sampling may have lower variance than importance sampling; thereby providing a theoretical justification for preferring it over importance sampling. Our empirical evaluation demonstrates that AND/OR importance sampling is ...

  8. Do resettlement variables predict psychiatric treatment outcomes in a sample of asylum-seeking survivors of torture?

    Science.gov (United States)

    Whitsett, David; Sherman, Martin F

    2017-12-01

    Mental health clinicians who work with asylum seekers provide services to patients who face stressful everyday living conditions. However, little is known about how these problems potentially impact psychiatric treatment within these populations. The purpose of this study was thus to examine whether resettlement factors predict outcomes of a mental health intervention for a sample of asylum-seeking survivors of torture. The study included data from a US outpatient clinic that specialized in treating asylum-seeking survivors of torture. Patients (primarily from Iraq, Afghanistan and African Countries) were evaluated on demographic factors at intake and psychiatric symptoms throughout the course of treatment. Patients experienced significant reductions in depression, anxiety and trauma symptoms, although symptoms still remained near or above clinical thresholds. Stable, uncrowded housing conditions significantly predicted lower depression, anxiety and trauma symptoms at follow-up. These findings support the hypotheses that individuals seeking asylum within the United States who have survived torture can benefit from psychiatric treatment and emphasize the importance of stable living conditions in improving treatment effectiveness. This suggests the need for further research on social predictors of treatment outcomes, as well as the need for clinicians and policymakers to target improved housing as a potentially important tool to reduce psychiatric problems related to torture and forced migration.

  9. Life course persistent and adolescence limited conduct disorder in a nationally representative US sample: prevalence, predictors, and outcomes.

    Science.gov (United States)

    Moore, Ashlee A; Silberg, Judy L; Roberson-Nay, Roxann; Mezuk, Briana

    2017-04-01

    The course of conduct disorder (CD) is heterogeneous. Moffitt proposed the heuristic of life course persistent (LCP) and adolescence limited (AL) to differentiate etiologically distinct forms of antisocial behavior (AB), each with distinct predictors and consequences, although a few studies have assessed this demarcation within the context of CD. The objective of this study was to apply Moffitt's taxonomy in a nationally representative US sample to investigate the prevalence, predictors, and outcomes of LCP and AL CD. Data come from the Collaborative Psychiatric Epidemiology Studies, a set of population-based nationally representative cross-sectional surveys (N = 20,130). Predictors included harsh discipline, maternal and paternal closeness, poverty in childhood, history of learning disability, parental deviance, and nativity. Outcomes included substance use, employment status, education attainment, marital status, income level, and self-rated mental and physical health. The prevalence of LCP and AL CD was 0.5 and 4.6%, respectively, for females, and 1.9 and 5.1%, respectively, for males. Low childhood SES [Odds Ratio (OR) = 3.49], lack of maternal closeness (OR = 2.50), and history of harsh discipline (OR = 2.17) increased odds of LCP group membership. The LCP group had higher odds of developing substance use disorders (OR = 2.00) relative to AL. LCP CD is more strongly influenced by childhood environment and confers increased odds for substance use problems in adulthood relative to AL CD.

  10. Outcomes of empirical eating disorder phenotypes in a clinical female sample: results from a latent class analysis.

    Science.gov (United States)

    Dechartres, Agnes; Huas, Caroline; Godart, Nathalie; Pousset, Maud; Pham, Alexandra; Divac, Snezana M; Rouillon, Frederic; Falissard, Bruno

    2011-01-01

    To empirically classify phenotypes of eating disorders (ED) using latent class analysis (LCA), and to validate this classification based on clinical outcomes. LCA was applied to 968 inpatients. The resultant classes were validated by clinical outcomes including mortality. A 5-class solution showed the best fit. The symptoms of latent class 1 (LC1; 26% of the sample) resembled anorexia nervosa (AN), bingeing-purging (AN-B/P) subtype; those of LC2 (23%) resembled bulimia nervosa; those of LC3 (11%) were close to AN-B/P without weight and body concerns; those of LC4 resembled restrictive anorexia nervosa (RAN) without weight and body concerns, and those of LC5 RAN. A history of hospitalization for ED was significantly more frequent for LC3 and LC4. The lowest BMI at admission were presented in LC4. LC1 showed the highest level of psychological disturbances and LC4 the lowest. LC3 and LC4 differed from LC1 and LC5 by higher percentages of treatment dropout (64.9 vs. 57.2 and 55.7 vs. 47.5%, respectively; overall p = 0.001). Survival rates tended to be different between the LC (p = 0.09). Subgroups of AN patients with low weight and body concerns seem more severe at hospitalization and more difficult to manage, with a higher rate of treatment dropout than the 'typical' AN patients. Copyright © 2010 S. Karger AG, Basel.

  11. Sample collection and documentation

    International Nuclear Information System (INIS)

    Cullings, Harry M.; Fujita, Shoichiro; Watanabe, Tadaaki; Yamashita, Tomoaki; Tanaka, Kenichi; Endo, Satoru; Shizuma, Kiyoshi; Hoshi, Masaharu; Hasai, Hiromi

    2005-01-01

    Beginning within a few weeks after the bombings and periodically during the intervening decades, investigators in Hiroshima and Nagasaki have collected samples of materials that were in the cities at the time of the bombings. Although some early efforts were not driven by specific measurement objectives, many others were. Even some of the very earliest samples collected in 1945 were based on carefully conceived research plans and detailed specifications for samples appropriate to particular retrospective measurements, i.e., of particular residual quantities remaining from exposure to the neutrons and gamma rays from the bombs. This chapter focuses mainly on the work of groups at two institutions that have actively collaborated since the 1980s in major collection efforts and have shared samples among themselves and with other investigators: the Radiation Effects Research Foundation (RERF) and its predecessor the Atomic Bomb Casualty Commission (ABCC), and Hiroshima University. In addition, a number of others are listed, who also contributed to the literature by their collection of samples. (J.P.N.)

  12. Groundwater sampling: Chapter 5

    Science.gov (United States)

    Wang, Qingren; Munoz-Carpena, Rafael; Foster, Adam; Migliaccio, Kati W.; Li, Yuncong; Migliaccio, Kati

    2011-01-01

    About the book: As water quality becomes a leading concern for people and ecosystems worldwide, it must be properly assessed in order to protect water resources for current and future generations. Water Quality Concepts, Sampling, and Analyses supplies practical information for planning, conducting, or evaluating water quality monitoring programs. It presents the latest information and methodologies for water quality policy, regulation, monitoring, field measurement, laboratory analysis, and data analysis. The book addresses water quality issues, water quality regulatory development, monitoring and sampling techniques, best management practices, and laboratory methods related to the water quality of surface and ground waters. It also discusses basic concepts of water chemistry and hydrology related to water sampling and analysis; instrumentation; water quality data analysis; and evaluation and reporting results.

  13. INEL Sample Management Office

    International Nuclear Information System (INIS)

    Watkins, C.

    1994-01-01

    The Idaho National Engineering Laboratory (INEL) Sample Management Office (SMO) was formed as part of the EG ampersand G Idaho Environmental Restoration Program (ERP) in June, 1990. Since then, the SMO has been recognized and sought out by other prime contractors and programs at the INEL. Since December 1991, the DOE-ID Division Directors for the Environmental Restoration Division and Waste Management Division supported the expansion of the INEL ERP SMO into the INEL site wide SMO. The INEL SMO serves as a point of contact for multiple environmental analytical chemistry and laboratory issues (e.g., capacity, capability). The SMO chemists work with project managers during planning to help develop data quality objectives, select appropriate analytical methods, identify special analytical services needs, identify a source for the services, and ensure that requirements for sampling and analysis (e.g., preservations, sample volumes) are clear and technically accurate. The SMO chemists also prepare work scope statements for the laboratories performing the analyses

  14. Independent random sampling methods

    CERN Document Server

    Martino, Luca; Míguez, Joaquín

    2018-01-01

    This book systematically addresses the design and analysis of efficient techniques for independent random sampling. Both general-purpose approaches, which can be used to generate samples from arbitrary probability distributions, and tailored techniques, designed to efficiently address common real-world practical problems, are introduced and discussed in detail. In turn, the monograph presents fundamental results and methodologies in the field, elaborating and developing them into the latest techniques. The theory and methods are illustrated with a varied collection of examples, which are discussed in detail in the text and supplemented with ready-to-run computer code. The main problem addressed in the book is how to generate independent random samples from an arbitrary probability distribution with the weakest possible constraints or assumptions in a form suitable for practical implementation. The authors review the fundamental results and methods in the field, address the latest methods, and emphasize the li...

  15. Radioactive air sampling methods

    CERN Document Server

    Maiello, Mark L

    2010-01-01

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

  16. Interactive Sample Book (ISB)

    DEFF Research Database (Denmark)

    Heimdal, Elisabeth Jacobsen; Lenau, Torben Anker; Guglielmi, Michel

    2009-01-01

    supervisor Torben A. Lenau. Inspiration to use smart materials Interactive textiles are still quite an unknown phenomenon to many. It is thus often difficult to communicate what kind of potentials lie within these materials. This is why the ISB project was started, as a practice based research project...... and senses in relation to integrated decoration and function primarily to indoor applications. The result of the project will be a number of interactive textiles, to be gathered in an interactive sample book (ISB), in a similar way as the sample books of wallpapers one can take home from the shop and choose...... from. In other words, it is a kind of display material, which in a simple manner can illustrate how different techniques and smart materials work. The sample book should display a number of possibilities where sensor technology, smart materials and textiles are mixed to such an extent that the textile...

  17. Analysis of monazite samples

    International Nuclear Information System (INIS)

    Kartiwa Sumadi; Yayah Rohayati

    1996-01-01

    The 'monazit' analytical program has been set up for routine work of Rare Earth Elements analysis in the monazite and xenotime minerals samples. Total relative error of the analysis is very low, less than 2.50%, and the reproducibility of counting statistic and stability of the instrument were very excellent. The precision and accuracy of the analytical program are very good with the maximum percentage relative are 5.22% and 1.61%, respectively. The mineral compositions of the 30 monazite samples have been also calculated using their chemical constituents, and the results were compared to the grain counting microscopic analysis

  18. Liquid waste sampling device

    International Nuclear Information System (INIS)

    Kosuge, Tadashi

    1998-01-01

    A liquid pumping pressure regulator is disposed on the midway of a pressure control tube which connects the upper portion of a sampling pot and the upper portion of a liquid waste storage vessel. With such a constitution, when the pressure in the sampling pot is made negative, and liquid wastes are sucked to the liquid pumping tube passing through the sampling pot, the difference between the pressure on the entrance of the liquid pumping pressure regulator of the pressure regulating tube and the pressure at the bottom of the liquid waste storage vessel is made constant. An opening degree controlling meter is disposed to control the degree of opening of a pressure regulating valve for sending actuation pressurized air to the liquid pumping pressure regulator. Accordingly, even if the liquid level of liquid wastes in the liquid waste storage vessel is changed, the height for the suction of the liquid wastes in the liquid pumping tube can be kept constant. With such procedures, sampling can be conducted correctly, and the discharge of the liquid wastes to the outside can be prevented. (T.M.)

  19. IXM gas sampling procedure

    International Nuclear Information System (INIS)

    Pingel, L.A.

    1995-01-01

    Ion Exchange Modules (IXMs) are used at the 105-KE and -KW Fuel Storage Basins to control radionuclide concentrations in the water. A potential safety concern relates to production of hydrogen gas by radiolysis of the water trapped in the ion exchange media of spent IXMs. This document provides a procedure for sampling the gases in the head space of the IXM

  20. Request for wood samples

    NARCIS (Netherlands)

    NN,

    1977-01-01

    In recent years the wood collection at the Rijksherbarium was greatly expanded following a renewed interest in wood anatomy as an aid for solving classification problems. Staff members of the Rijksherbarium added to the collection by taking interesting wood samples with them from their expeditions

  1. Check Sample Abstracts.

    Science.gov (United States)

    Alter, David; Grenache, David G; Bosler, David S; Karcher, Raymond E; Nichols, James; Rajadhyaksha, Aparna; Camelo-Piragua, Sandra; Rauch, Carol; Huddleston, Brent J; Frank, Elizabeth L; Sluss, Patrick M; Lewandrowski, Kent; Eichhorn, John H; Hall, Janet E; Rahman, Saud S; McPherson, Richard A; Kiechle, Frederick L; Hammett-Stabler, Catherine; Pierce, Kristin A; Kloehn, Erica A; Thomas, Patricia A; Walts, Ann E; Madan, Rashna; Schlesinger, Kathie; Nawgiri, Ranjana; Bhutani, Manoop; Kanber, Yonca; Abati, Andrea; Atkins, Kristen A; Farrar, Robert; Gopez, Evelyn Valencerina; Jhala, Darshana; Griffin, Sonya; Jhala, Khushboo; Jhala, Nirag; Bentz, Joel S; Emerson, Lyska; Chadwick, Barbara E; Barroeta, Julieta E; Baloch, Zubair W; Collins, Brian T; Middleton, Owen L; Davis, Gregory G; Haden-Pinneri, Kathryn; Chu, Albert Y; Keylock, Joren B; Ramoso, Robert; Thoene, Cynthia A; Stewart, Donna; Pierce, Arand; Barry, Michelle; Aljinovic, Nika; Gardner, David L; Barry, Michelle; Shields, Lisa B E; Arnold, Jack; Stewart, Donna; Martin, Erica L; Rakow, Rex J; Paddock, Christopher; Zaki, Sherif R; Prahlow, Joseph A; Stewart, Donna; Shields, Lisa B E; Rolf, Cristin M; Falzon, Andrew L; Hudacki, Rachel; Mazzella, Fermina M; Bethel, Melissa; Zarrin-Khameh, Neda; Gresik, M Vicky; Gill, Ryan; Karlon, William; Etzell, Joan; Deftos, Michael; Karlon, William J; Etzell, Joan E; Wang, Endi; Lu, Chuanyi M; Manion, Elizabeth; Rosenthal, Nancy; Wang, Endi; Lu, Chuanyi M; Tang, Patrick; Petric, Martin; Schade, Andrew E; Hall, Geraldine S; Oethinger, Margret; Hall, Geraldine; Picton, Avis R; Hoang, Linda; Imperial, Miguel Ranoa; Kibsey, Pamela; Waites, Ken; Duffy, Lynn; Hall, Geraldine S; Salangsang, Jo-Anne M; Bravo, Lulette Tricia C; Oethinger, Margaret D; Veras, Emanuela; Silva, Elvia; Vicens, Jimena; Silva, Elvio; Keylock, Joren; Hempel, James; Rushing, Elizabeth; Posligua, Lorena E; Deavers, Michael T; Nash, Jason W; Basturk, Olca; Perle, Mary Ann; Greco, Alba; Lee, Peng; Maru, Dipen; Weydert, Jamie Allen; Stevens, Todd M; Brownlee, Noel A; Kemper, April E; Williams, H James; Oliverio, Brock J; Al-Agha, Osama M; Eskue, Kyle L; Newlands, Shawn D; Eltorky, Mahmoud A; Puri, Puja K; Royer, Michael C; Rush, Walter L; Tavora, Fabio; Galvin, Jeffrey R; Franks, Teri J; Carter, James Elliot; Kahn, Andrea Graciela; Lozada Muñoz, Luis R; Houghton, Dan; Land, Kevin J; Nester, Theresa; Gildea, Jacob; Lefkowitz, Jerry; Lacount, Rachel A; Thompson, Hannis W; Refaai, Majed A; Quillen, Karen; Lopez, Ana Ortega; Goldfinger, Dennis; Muram, Talia; Thompson, Hannis

    2009-02-01

    The following abstracts are compiled from Check Sample exercises published in 2008. These peer-reviewed case studies assist laboratory professionals with continuing medical education and are developed in the areas of clinical chemistry, cytopathology, forensic pathology, hematology, microbiology, surgical pathology, and transfusion medicine. Abstracts for all exercises published in the program will appear annually in AJCP.

  2. Demonstrating the reliability of transdiagnostic mHealth Routine Outcome Monitoring in mental health services using experience sampling technology.

    Directory of Open Access Journals (Sweden)

    Simone J W Verhagen

    Full Text Available Routine Outcome Monitoring (ROM should provide a dynamic, within-treatment forward feedback loop to guide individual treatment decisions across diagnostic categories. It has been suggested that the Experience Sampling Method (ESM, capturing the film of daily life adaptive processes, offers a flexible, personalised and transdiagnostic feedback system for monitoring and adapting treatment strategies. This is the first study that uses an ESM application (the PsyMate™ as a routine mobile-ROM (mROM tool in an ambulatory mental health setting.To demonstrate adequate psychometric properties of the PsyMate™ app assessing both symptom severity levels as well as daily life functioning.In a transdiagnostic sample of 64 outpatients, an mROM protocol (ESM for 6 days, at 10 semi-random moments a day and a standard ROM instrument (HADS were administered at baseline and at three-month follow-up. We measured positive affect (PA, negative affect (NA, quality of sleep, positive social interaction, activity-related stress, tiredness, and feeling unwell.Subjects completed 53% of the measurements at baseline (N = 64 and 48% at follow-up (N = 29. Factor analysis and subsequent reliability analysis of PA and NA confirmed the two constructs. Significant and meaningful correlations were found between PA, NA and HADS scores (ranging from r = .4 to r = .7. Multilevel analyses yielded significant change scores for all measures.The ESM-based, transdiagnostic mROM tool can be used reliably in clinical settings: it shows adequate psychometric properties, as well as concurrent validity and sensitivity to change over time with respect to relevant ROM constructs. Person-tailored items can be added. In addition, mROM offers added value over standard symptom-based ROM, as it provides information on adaptive functioning in the daily environment of patients.

  3. Biological Sampling Variability Study

    Energy Technology Data Exchange (ETDEWEB)

    Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-11-08

    There are many sources of variability that exist in the sample collection and analysis process. This paper addresses many, but not all, sources of variability. The main focus of this paper was to better understand and estimate variability due to differences between samplers. Variability between days was also studied, as well as random variability within each sampler. Experiments were performed using multiple surface materials (ceramic and stainless steel), multiple contaminant concentrations (10 spores and 100 spores), and with and without the presence of interfering material. All testing was done with sponge sticks using 10-inch by 10-inch coupons. Bacillus atrophaeus was used as the BA surrogate. Spores were deposited using wet deposition. Grime was coated on the coupons which were planned to include the interfering material (Section 3.3). Samples were prepared and analyzed at PNNL using CDC protocol (Section 3.4) and then cultured and counted. Five samplers were trained so that samples were taken using the same protocol. Each sampler randomly sampled eight coupons each day, four coupons with 10 spores deposited and four coupons with 100 spores deposited. Each day consisted of one material being tested. The clean samples (no interfering materials) were run first, followed by the dirty samples (coated with interfering material). There was a significant difference in recovery efficiency between the coupons with 10 spores deposited (mean of 48.9%) and those with 100 spores deposited (mean of 59.8%). There was no general significant difference between the clean and dirty (containing interfering material) coupons or between the two surface materials; however, there was a significant interaction between concentration amount and presence of interfering material. The recovery efficiency was close to the same for coupons with 10 spores deposited, but for the coupons with 100 spores deposited, the recovery efficiency for the dirty samples was significantly larger (65

  4. Nonadiabatic transition path sampling

    International Nuclear Information System (INIS)

    Sherman, M. C.; Corcelli, S. A.

    2016-01-01

    Fewest-switches surface hopping (FSSH) is combined with transition path sampling (TPS) to produce a new method called nonadiabatic path sampling (NAPS). The NAPS method is validated on a model electron transfer system coupled to a Langevin bath. Numerically exact rate constants are computed using the reactive flux (RF) method over a broad range of solvent frictions that span from the energy diffusion (low friction) regime to the spatial diffusion (high friction) regime. The NAPS method is shown to quantitatively reproduce the RF benchmark rate constants over the full range of solvent friction. Integrating FSSH within the TPS framework expands the applicability of both approaches and creates a new method that will be helpful in determining detailed mechanisms for nonadiabatic reactions in the condensed-phase.

  5. Cerenkov fiber sampling calorimeters

    International Nuclear Information System (INIS)

    Arrington, K.; Kefford, D.; Kennedy, J.; Pisani, R.; Sanzeni, C.; Segall, K.; Wall, D.; Winn, D.R.; Carey, R.; Dye, S.; Miller, J.; Sulak, L.; Worstell, W.; Efremenko, Y.; Kamyshkov, Y.; Savin, A.; Shmakov, K.; Tarkovsky, E.

    1994-01-01

    Clear optical fibers were used as a Cerenkov sampling media in Pb (electromagnetic) and Cu (hadron) absorbers in spaghetti calorimeters, for high rate and high radiation dose experiments, such as the forward region of high energy colliders. The fiber axes were aligned close to the direction of the incident particles (1 degree--7 degree). The 7 λ deep hadron tower contained 2.8% by volume 1.5 mm diameter core clear plastic fibers. The 27 radiation length deep electromagnetic towers had packing fractions of 6.8% and 7.2% of 1 mm diameter core quartz fibers as the active Cerenkov sampling medium. The energy resolution on electrons and pions, energy response, pulse shapes and angular studies are presented

  6. Low ficolin-3 levels in early follow-up serum samples are associated with the severity and unfavorable outcome of acute ischemic stroke

    DEFF Research Database (Denmark)

    Füst, George; Munthe-Fog, Lea; Illes, Zsolt

    2011-01-01

    demonstrated the significance of MBL in ischemic stroke, the role of ficolins has not been examined. METHODS: Sera were obtained within 12 hours after the onset of ischemic stroke (admission samples) and 3-4 days later (follow-up samples) from 65 patients. The control group comprised 100 healthy individuals......-up samples an inverse correlation was observed between ficolin-3 levels and concentration of S100β, an indicator of the size of cerebral infarct. Patients with low ficolin-3 levels and high CRP levels in the follow up samples had a significantly worse outcome (adjusted ORs 5.6 and 3.9, respectively...

  7. Digital Microfluidics Sample Analyzer

    Science.gov (United States)

    Pollack, Michael G.; Srinivasan, Vijay; Eckhardt, Allen; Paik, Philip Y.; Sudarsan, Arjun; Shenderov, Alex; Hua, Zhishan; Pamula, Vamsee K.

    2010-01-01

    Three innovations address the needs of the medical world with regard to microfluidic manipulation and testing of physiological samples in ways that can benefit point-of-care needs for patients such as premature infants, for which drawing of blood for continuous tests can be life-threatening in their own right, and for expedited results. A chip with sample injection elements, reservoirs (and waste), droplet formation structures, fluidic pathways, mixing areas, and optical detection sites, was fabricated to test the various components of the microfluidic platform, both individually and in integrated fashion. The droplet control system permits a user to control droplet microactuator system functions, such as droplet operations and detector operations. Also, the programming system allows a user to develop software routines for controlling droplet microactuator system functions, such as droplet operations and detector operations. A chip is incorporated into the system with a controller, a detector, input and output devices, and software. A novel filler fluid formulation is used for the transport of droplets with high protein concentrations. Novel assemblies for detection of photons from an on-chip droplet are present, as well as novel systems for conducting various assays, such as immunoassays and PCR (polymerase chain reaction). The lab-on-a-chip (a.k.a., lab-on-a-printed-circuit board) processes physiological samples and comprises a system for automated, multi-analyte measurements using sub-microliter samples of human serum. The invention also relates to a diagnostic chip and system including the chip that performs many of the routine operations of a central labbased chemistry analyzer, integrating, for example, colorimetric assays (e.g., for proteins), chemiluminescence/fluorescence assays (e.g., for enzymes, electrolytes, and gases), and/or conductometric assays (e.g., for hematocrit on plasma and whole blood) on a single chip platform.

  8. Underwater Sediment Sampling Research

    Science.gov (United States)

    2017-01-01

    impacted sediments was found to be directly related to the concentration of crude oil detected in the sediment pore waters . Applying this mathematical...Kurt.A.Hansen@uscg.mil. 16. Abstract (MAXIMUM 200 WORDS ) The USCG R&D Center sought to develop a bench top system to determine the amount of total...scattered. The approach here is to sample the interstitial water between the grains of sand and attempt to determine the amount of oil in and on

  9. ITOUGH2 sample problems

    International Nuclear Information System (INIS)

    Finsterle, S.

    1997-11-01

    This report contains a collection of ITOUGH2 sample problems. It complements the ITOUGH2 User's Guide [Finsterle, 1997a], and the ITOUGH2 Command Reference [Finsterle, 1997b]. ITOUGH2 is a program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis. It is based on the TOUGH2 simulator for non-isothermal multiphase flow in fractured and porous media [Preuss, 1987, 1991a]. The report ITOUGH2 User's Guide [Finsterle, 1997a] describes the inverse modeling framework and provides the theoretical background. The report ITOUGH2 Command Reference [Finsterle, 1997b] contains the syntax of all ITOUGH2 commands. This report describes a variety of sample problems solved by ITOUGH2. Table 1.1 contains a short description of the seven sample problems discussed in this report. The TOUGH2 equation-of-state (EOS) module that needs to be linked to ITOUGH2 is also indicated. Each sample problem focuses on a few selected issues shown in Table 1.2. ITOUGH2 input features and the usage of program options are described. Furthermore, interpretations of selected inverse modeling results are given. Problem 1 is a multipart tutorial, describing basic ITOUGH2 input files for the main ITOUGH2 application modes; no interpretation of results is given. Problem 2 focuses on non-uniqueness, residual analysis, and correlation structure. Problem 3 illustrates a variety of parameter and observation types, and describes parameter selection strategies. Problem 4 compares the performance of minimization algorithms and discusses model identification. Problem 5 explains how to set up a combined inversion of steady-state and transient data. Problem 6 provides a detailed residual and error analysis. Finally, Problem 7 illustrates how the estimation of model-related parameters may help compensate for errors in that model

  10. Lunar sample studies

    International Nuclear Information System (INIS)

    1977-01-01

    Lunar samples discussed and the nature of their analyses are: (1) an Apollo 15 breccia which is thoroughly analyzed as to the nature of the mature regolith from which it derived and the time and nature of the lithification process, (2) two Apollo 11 and one Apollo 12 basalts analyzed in terms of chemistry, Cross-Iddings-Pirsson-Washington norms, mineralogy, and petrography, (3) eight Apollo 17 mare basalts, also analyzed in terms of chemistry, Cross-Iddings-Pirsson-Washington norms, mineralogy, and petrography. The first seven are shown to be chemically similar although of two main textural groups; the eighth is seen to be distinct in both chemistry and mineralogy, (4) a troctolitic clast from a Fra Mauro breccia, analyzed and contrasted with other high-temperature lunar mineral assemblages. Two basaltic clasts from the same breccia are shown to have affinities with rock 14053, and (5) the uranium-thorium-lead systematics of three Apollo 16 samples are determined; serious terrestrial-lead contamination of the first two samples is attributed to bandsaw cutting in the lunar curatorial facility

  11. Sustainable Mars Sample Return

    Science.gov (United States)

    Alston, Christie; Hancock, Sean; Laub, Joshua; Perry, Christopher; Ash, Robert

    2011-01-01

    The proposed Mars sample return mission will be completed using natural Martian resources for the majority of its operations. The system uses the following technologies: In-Situ Propellant Production (ISPP), a methane-oxygen propelled Mars Ascent Vehicle (MAV), a carbon dioxide powered hopper, and a hydrogen fueled balloon system (large balloons and small weather balloons). The ISPP system will produce the hydrogen, methane, and oxygen using a Sabatier reactor. a water electrolysis cell, water extracted from the Martian surface, and carbon dioxide extracted from the Martian atmosphere. Indigenous hydrogen will fuel the balloon systems and locally-derived methane and oxygen will fuel the MAV for the return of a 50 kg sample to Earth. The ISPP system will have a production cycle of 800 days and the estimated overall mission length is 1355 days from Earth departure to return to low Earth orbit. Combining these advanced technologies will enable the proposed sample return mission to be executed with reduced initial launch mass and thus be more cost efficient. The successful completion of this mission will serve as the next step in the advancement of Mars exploration technology.

  12. Bottom sample taker

    Energy Technology Data Exchange (ETDEWEB)

    Garbarenko, O V; Slonimskiy, L D

    1982-01-01

    In order to improve the quality of the samples taken during offshore exploration from benthic sediments, the proposed design of the sample taker has a device which makes it possible to regulate the depth of submersion of the core lifter. For this purpose the upper part of the core lifter has an inner delimiting ring, and within the core lifter there is a piston suspended on a cable. The position of the piston in relation to the core lifter is previously assigned depending on the compactness of the benthic sediments and is fixed by tension of the cable which is held by a clamp in the cover of the core taker housing. When lowered to the bottom, the core taker is released, and under the influence of hydrostatic pressure of sea water, it enters the sediments. The magnitude of penetration is limited by the distance between the piston and the stopping ring. The piston also guarantees better preservation of the sample when the instrument is lifted to the surface.

  13. Sample-taking apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Tanov, Y I; Ismailov, R A; Orazov, A

    1980-10-07

    The invention refers to the equipment for testing water-bearing levels in loose rocks. Its purpose is to simultaneously remove with the rock sample a separate fluid sample from the assigned interval. The sample-taking apparatus contains a core lifter which can be submerged into the casting string with housing and front endpiece in the form of a rod with a piston which covers the cavity of the core lifter, as well as mechanism for fixing and moving the endpiece within the core lifter cavity. The device differs from the known similar devices because the upper part of the housing of the core lifter is equipped with a filter and mobile casting which covers the filter. In this case the casing is connected to the endpiece rod and the endpiece is installed with the possibility of movement which is limited with fixing in the upper position and in the extreme upper position it divides the core lifter cavity into two parts, filter settling tank and core-receiving cavity.

  14. Visualizing the Sample Standard Deviation

    Science.gov (United States)

    Sarkar, Jyotirmoy; Rashid, Mamunur

    2017-01-01

    The standard deviation (SD) of a random sample is defined as the square-root of the sample variance, which is the "mean" squared deviation of the sample observations from the sample mean. Here, we interpret the sample SD as the square-root of twice the mean square of all pairwise half deviations between any two sample observations. This…

  15. NID Copper Sample Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Zhu, Zihua

    2011-09-12

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one under development at Nonlinear Ion Dynamics (NID), will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.

  16. Race/ethnicity and socio-economic differences in colorectal cancer surgery outcomes: analysis of the nationwide inpatient sample.

    Science.gov (United States)

    Akinyemiju, Tomi; Meng, Qingrui; Vin-Raviv, Neomi

    2016-09-05

    The purpose of this study was to examine racial and socio-economic differences in the receipt of laparoscopic or open surgery among patients with colorectal cancer, and to determine if racial and socio-economic differences exist in post-surgical complications, in-hospital mortality and hospital length of stay among patients who received surgery. We conducted a cross-sectional analysis of hospitalized patients with a primary diagnosis of colorectal cancer between 2007 and 2011 using data from Nationwide Inpatient Sample. ICD-9 codes were used to capture primary diagnosis, surgical procedures, and health outcomes during hospitalization. We used logistic regression analysis to determine racial and socio-economic predictors of surgery type, post-surgical complications and mortality, and linear regression analysis to assess hospital length of stay. A total of 122,631 patients were admitted with a primary diagnosis of malignant colorectal cancer between 2007 and 2011. Of these, 17,327 (14.13 %) had laparoscopic surgery, 70,328 (57.35 %) received open surgery, while 34976 (28.52 %) did not receive any surgery. Black (36 %) and Hispanic (34 %) patients were more likely to receive no surgery compared with Whites (27 %) patients. However, among patients that received any surgery, there were no racial differences in which surgery was received (laparoscopic versus open, p = 0.2122), although socio-economic differences remained, with patients from lower residential income areas significantly less likely to receive laparoscopic surgery compared with patients from higher residential income areas (OR: 0.74, 95 % CI: 0.70-0.78). Among patients who received any surgery, Black patients (OR = 1.07, 95 % CI: 1.01-1.13), and patients with Medicare (OR = 1.16, 95 % CI: 1.11-1.22) and Medicaid (OR = 1.15, 95 % CI: 1.07-1.25) insurance experienced significantly higher post-surgical complications, in-hospital mortality (Black OR = 1.18, 95 % CI: 1.00-1.39), and

  17. Fatal and non-fatal injury outcomes: results from a purposively sampled census of seven rural subdistricts in Bangladesh.

    Science.gov (United States)

    Alonge, Olakunle; Agrawal, Priyanka; Talab, Abu; Rahman, Qazi S; Rahman, Akm Fazlur; Arifeen, Shams El; Hyder, Adnan A

    2017-08-01

    90% of the global burden of injuries is borne by low-income and middle-income countries (LMICs). However, details of the injury burden in LMICs are less clear because of the scarcity of data and population-based studies. The Saving of Lives from Drowning project, implemented in rural Bangladesh, did a census on 1·2 million people to fill this gap. This Article describes the epidemiology of fatal and non-fatal injuries from the study. In this study, we used data from the baseline census conducted as part of the Saving of Lives from Drowning (SoLiD) project. The census was implemented in 51 unions from seven purposively sampled rural subdistricts of Bangladesh between June and November, 2013. Sociodemographic, injury mortality, and morbidity information were collected for the whole population in the study area. We analysed the data for descriptive measures of fatal and non-fatal injury outcomes. Age and gender distribution, socioeconomic characteristics, and injury characteristics such as external cause, intent, location, and body part affected were reported for all injury outcomes. The census covered a population of 1 169 593 from 270 387 households and 451 villages. The overall injury mortality rate was 38 deaths per 100 000 population per year, and 104 703 people sustained major non-fatal injuries over a 6-month recall period. Drowning was the leading external cause of injury death for all ages, and falls caused the most number of non-fatal injuries. Fatal injury rates were highest in children aged 1-4 years. Non-fatal injury rates were also highest in children aged 1-4 years and those aged 65 years and older. Males had more fatal and non-fatal injuries than females across all external causes except for burns. Suicide was the leading cause of injury deaths in individuals aged 15-24 years, and more than 50% of the suicides occurred in females. The home environment was the most common location for most injuries. The burden of fatal and non-fatal injuries

  18. 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 ...

  19. Systematic Sampling and Cluster Sampling of Packet Delays

    OpenAIRE

    Lindh, Thomas

    2006-01-01

    Based on experiences of a traffic flow performance meter this papersuggests and evaluates cluster sampling and systematic sampling as methods toestimate average packet delays. Systematic sampling facilitates for exampletime analysis, frequency analysis and jitter measurements. Cluster samplingwith repeated trains of periodically spaced sampling units separated by randomstarting periods, and systematic sampling are evaluated with respect to accuracyand precision. Packet delay traces have been ...

  20. NID Copper Sample Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Zhu, Zihua

    2011-02-01

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  1. Fluid sampling tool

    Science.gov (United States)

    Garcia, A.R.; Johnston, R.G.; Martinez, R.K.

    1999-05-25

    A fluid sampling tool is described for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall. 6 figs.

  2. NID Copper Sample Analysis

    International Nuclear Information System (INIS)

    Kouzes, Richard T.; Zhu, Zihua

    2011-01-01

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76 Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76 Ge. The DEMONSTRATOR will utilize 76 Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  3. Fluid sampling tool

    Science.gov (United States)

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    1999-05-25

    A fluid sampling tool for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall.

  4. Tritium sampling and measurement

    International Nuclear Information System (INIS)

    Wood, M.J.; McElroy, R.G.; Surette, R.A.; Brown, R.M.

    1993-01-01

    Current methods for sampling and measuring tritium are described. Although the basic techniques have not changed significantly over the last 10 y, there have been several notable improvements in tritium measurement instrumentation. The design and quality of commercial ion-chamber-based and gas-flow-proportional-counter-based tritium monitors for tritium-in-air have improved, an indirect result of fusion-related research in the 1980s. For tritium-in-water analysis, commercial low-level liquid scintillation spectrometers capable of detecting tritium-in-water concentrations as low as 0.65 Bq L-1 for counting times of 500 min are available. The most sensitive method for tritium-in-water analysis is still 3He mass spectrometry. Concentrations as low as 0.35 mBq L-1 can be detected with current equipment. Passive tritium-oxide-in-air samplers are now being used for workplace monitoring and even in some environmental sampling applications. The reliability, convenience, and low cost of passive tritium-oxide-in-air samplers make them attractive options for many monitoring applications. Airflow proportional counters currently under development look promising for measuring tritium-in-air in the presence of high gamma and/or noble gas backgrounds. However, these detectors are currently limited by their poor performance in humidities over 30%. 133 refs

  5. Sample size and number of outcome measures of veterinary randomised controlled trials of pharmaceutical interventions funded by different sources, a cross-sectional study.

    Science.gov (United States)

    Wareham, K J; Hyde, R M; Grindlay, D; Brennan, M L; Dean, R S

    2017-10-04

    Randomised controlled trials (RCTs) are a key component of the veterinary evidence base. Sample sizes and defined outcome measures are crucial components of RCTs. To describe the sample size and number of outcome measures of veterinary RCTs either funded by the pharmaceutical industry or not, published in 2011. A structured search of PubMed identified RCTs examining the efficacy of pharmaceutical interventions. Number of outcome measures, number of animals enrolled per trial, whether a primary outcome was identified, and the presence of a sample size calculation were extracted from the RCTs. The source of funding was identified for each trial and groups compared on the above parameters. Literature searches returned 972 papers; 86 papers comprising 126 individual trials were analysed. The median number of outcomes per trial was 5.0; there were no significant differences across funding groups (p = 0.133). The median number of animals enrolled per trial was 30.0; this was similar across funding groups (p = 0.302). A primary outcome was identified in 40.5% of trials and was significantly more likely to be stated in trials funded by a pharmaceutical company. A very low percentage of trials reported a sample size calculation (14.3%). Failure to report primary outcomes, justify sample sizes and the reporting of multiple outcome measures was a common feature in all of the clinical trials examined in this study. It is possible some of these factors may be affected by the source of funding of the studies, but the influence of funding needs to be explored with a larger number of trials. Some veterinary RCTs provide a weak evidence base and targeted strategies are required to improve the quality of veterinary RCTs to ensure there is reliable evidence on which to base clinical decisions.

  6. Sampling and examination methods used for TMI-2 samples

    International Nuclear Information System (INIS)

    Marley, A.W.; Akers, D.W.; McIsaac, C.V.

    1988-01-01

    The purpose of this paper is to summarize the sampling and examination techniques that were used in the collection and analysis of TMI-2 samples. Samples ranging from auxiliary building air to core debris were collected and analyzed. Handling of the larger samples and many of the smaller samples had to be done remotely and many standard laboratory analytical techniques were modified to accommodate the extremely high radiation fields associated with these samples. The TMI-2 samples presented unique problems with sampling and the laboratory analysis of prior molten fuel debris. 14 refs., 8 figs

  7. Adrenal vein sampling versus CT scan to determine treatment in primary aldosteronism : an outcome-based randomised diagnostic trial

    NARCIS (Netherlands)

    Dekkers, Tanja; Prejbisz, Aleksander; Kool, Leo J. Schultze; Groenewoud, Hans J. M. M.; Velema, Marieke; Spiering, Wilko; Kolodziejczyk-Kruk, Sylwia; Arntz, Mark; Kadziela, Jacek; Langenhuijsen, Johannes F.; Kerstens, Michiel N.; van den Meiracker, Anton H.; van den Born, Bert-Jan; Sweep, Fred C. G. J.; Hermus, Ad R. M. M.; Januszewicz, Andrzej; Ligthart-Naber, Alike F.; Makai, Peter; van der Wilt, Gert-Jan; Lenders, Jacques W. M.; Deinum, Jaap

    Background The distinction between unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia as causes of primary aldosteronism is usually made by adrenal CT or by adrenal vein sampling (AVS). Whether CT or AVS represents the best test for diagnosis remains unknown. We aimed to

  8. Assessing the Impact of Harassment by Peers: Incident Characteristics and Outcomes in a National Sample of Youth

    Science.gov (United States)

    Turner, Heather A.; Mitchell, Kimberly J.; Jones, Lisa; Shattuck, Anne

    2017-01-01

    Although there are widely held assumptions about the characteristics of peer bullying that are of greatest concern, very few studies have empirically assessed which characteristics most affect its impact. The current research addresses this gap by using a nationally representative U.S. sample of youth ages 10-20 to examine the relative effects of…

  9. Trace of heavy metals in maternal and umbilical cord blood samples in association with birth outcomes in Baghdad, Iraq

    Science.gov (United States)

    Hasan Rhaif Al-Sahlanee, Mayyadah; Maizan Ramli, Ramzun; Abdul Hassan Ali, Miami; Fadhil Tawfiq, Nada; Zahirah Noor Azman, Nurul; Abdul Rahman, Azhar; Shahrim Mustafa, Iskandar; Noor Ashikin Nik Abdul Razak, Nik; Zakiah Yahaya, Nor; Mohammed Al-Marri, Hana; Syuhada Ayob, Nur; Zakaria, Nabela

    2017-10-01

    Trace elements are essential nutritional components in humans and inconvenient tissue content that have a significant influence on infant size. The aim of this study is to evaluate the effects of concentration of elements (uranium (U), lead (Pb) and iron (Fe)) and absorption of Pb and Fe on maternal and umbilical cord blood samples. The concentration and absorption of Pb and Fe in blood samples were determined by using atomic absorption spectrophotometry device, while the uranium concentration was determined by using CR-39 detector. Fifty women of age 16-44 years are involved in this study. Results show that the maximum and minimum values of both concentration and absorption in the maternal samples were for Pb and Fe, respectively. In addition, for umbilical cord, the maximum values of concentration and absorption were for Fe and the minimum concentration and absorption were for U and Pb, respectively. A significant correlation between maternal and umbilical cord blood samples was found. This indicates that the Pb, U and Fe elements can easily transfer from maternal to the fetal body which impacts the growth of fetus.

  10. On sampling social networking services

    OpenAIRE

    Wang, Baiyang

    2012-01-01

    This article aims at summarizing the existing methods for sampling social networking services and proposing a faster confidence interval for related sampling methods. It also includes comparisons of common network sampling techniques.

  11. Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

    International Nuclear Information System (INIS)

    Shine, E. P.; Poirier, M. R.

    2013-01-01

    Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and

  12. Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

    Energy Technology Data Exchange (ETDEWEB)

    Shine, E. P.; Poirier, M. R.

    2013-10-29

    Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and

  13. Coupling methods for multistage sampling

    OpenAIRE

    Chauvet, Guillaume

    2015-01-01

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

  14. A method of language sampling

    DEFF Research Database (Denmark)

    Rijkhoff, Jan; Bakker, Dik; Hengeveld, Kees

    1993-01-01

    In recent years more attention is paid to the quality of language samples in typological work. Without an adequate sampling strategy, samples may suffer from various kinds of bias. In this article we propose a sampling method in which the genetic criterion is taken as the most important: samples...... to determine how many languages from each phylum should be selected, given any required sample size....

  15. Sampling airborne radioactivity

    International Nuclear Information System (INIS)

    Cohen, B.S.

    1988-01-01

    Radioactive contaminants have historically been considered apart from chemical contaminants because it is their radiological properties that determine their biological and environmental impact. Additionally they have been regulated by special government agencies concerned with radiological protection. Radioactive contaminants are also distinguished by the specialized and very sensitive methods available for the detection of radioactivity. Measurements of a few thousand atoms per liter are not uncommon. Radiation detectors in common use are gas filled chambers, scintillation and semiconductor detectors, and the more recently developed thermoluminescent and etched track detectors. Solid-state nuclear track detectors consist of a large group of inorganic and organic dielectrics which register tracks when traversed by heavy charged particles. They do not respond to light, beta particles or gamma ray photons and thus provide a very low background system for the detection of extremely low levels of radioactivity. In addition, no power source or electronic equipment is required. Cellulose nitrate detectors are currently in use for long term integrated sampling of environmental radon. Thermoluminescent dosimeters (TID's) are crystalline materials, in which electrons which have been displaced by an interaction with ionizing radiation become trapped at an elevated energy level and emit visible light when released from that energy level. As which etched-track detectors no power or electronic equipment is needed for the TID's at a measurement site, but they respond to alpha, beta and gamma radiation. Thermoluminescent dosimeters are useful for long term environmental monitoring, and have also been newly incorporated into integrating radon detection systems

  16. Enhanced sampling algorithms.

    Science.gov (United States)

    Mitsutake, Ayori; Mori, Yoshiharu; Okamoto, Yuko

    2013-01-01

    In biomolecular systems (especially all-atom models) with many degrees of freedom such as proteins and nucleic acids, there exist an astronomically large number of local-minimum-energy states. Conventional simulations in the canonical ensemble are of little use, because they tend to get trapped in states of these energy local minima. Enhanced conformational sampling techniques are thus in great demand. A simulation in generalized ensemble performs a random walk in potential energy space and can overcome this difficulty. From only one simulation run, one can obtain canonical-ensemble averages of physical quantities as functions of temperature by the single-histogram and/or multiple-histogram reweighting techniques. In this article we review uses of the generalized-ensemble algorithms in biomolecular systems. Three well-known methods, namely, multicanonical algorithm, simulated tempering, and replica-exchange method, are described first. Both Monte Carlo and molecular dynamics versions of the algorithms are given. We then present various extensions of these three generalized-ensemble algorithms. The effectiveness of the methods is tested with short peptide and protein systems.

  17. Quantum Metropolis sampling.

    Science.gov (United States)

    Temme, K; Osborne, T J; Vollbrecht, K G; Poulin, D; Verstraete, F

    2011-03-03

    The original motivation to build a quantum computer came from Feynman, who imagined a machine capable of simulating generic quantum mechanical systems--a task that is believed to be intractable for classical computers. Such a machine could have far-reaching applications in the simulation of many-body quantum physics in condensed-matter, chemical and high-energy systems. Part of Feynman's challenge was met by Lloyd, who showed how to approximately decompose the time evolution operator of interacting quantum particles into a short sequence of elementary gates, suitable for operation on a quantum computer. However, this left open the problem of how to simulate the equilibrium and static properties of quantum systems. This requires the preparation of ground and Gibbs states on a quantum computer. For classical systems, this problem is solved by the ubiquitous Metropolis algorithm, a method that has basically acquired a monopoly on the simulation of interacting particles. Here we demonstrate how to implement a quantum version of the Metropolis algorithm. This algorithm permits sampling directly from the eigenstates of the Hamiltonian, and thus evades the sign problem present in classical simulations. A small-scale implementation of this algorithm should be achievable with today's technology.

  18. [A comparison of convenience sampling and purposive sampling].

    Science.gov (United States)

    Suen, Lee-Jen Wu; Huang, Hui-Man; Lee, Hao-Hsien

    2014-06-01

    Convenience sampling and purposive sampling are two different sampling methods. This article first explains sampling terms such as target population, accessible population, simple random sampling, intended sample, actual sample, and statistical power analysis. These terms are then used to explain the difference between "convenience sampling" and purposive sampling." Convenience sampling is a non-probabilistic sampling technique applicable to qualitative or quantitative studies, although it is most frequently used in quantitative studies. In convenience samples, subjects more readily accessible to the researcher are more likely to be included. Thus, in quantitative studies, opportunity to participate is not equal for all qualified individuals in the target population and study results are not necessarily generalizable to this population. As in all quantitative studies, increasing the sample size increases the statistical power of the convenience sample. In contrast, purposive sampling is typically used in qualitative studies. Researchers who use this technique carefully select subjects based on study purpose with the expectation that each participant will provide unique and rich information of value to the study. As a result, members of the accessible population are not interchangeable and sample size is determined by data saturation not by statistical power analysis.

  19. A Bayesian Justification for Random Sampling in Sample Survey

    Directory of Open Access Journals (Sweden)

    Glen Meeden

    2012-07-01

    Full Text Available In the usual Bayesian approach to survey sampling the sampling design, plays a minimal role, at best. Although a close relationship between exchangeable prior distributions and simple random sampling has been noted; how to formally integrate simple random sampling into the Bayesian paradigm is not clear. Recently it has been argued that the sampling design can be thought of as part of a Bayesian's prior distribution. We will show here that under this scenario simple random sample can be given a Bayesian justification in survey sampling.

  20. Concepts in sample size determination

    Directory of Open Access Journals (Sweden)

    Umadevi K Rao

    2012-01-01

    Full Text Available Investigators involved in clinical, epidemiological or translational research, have the drive to publish their results so that they can extrapolate their findings to the population. This begins with the preliminary step of deciding the topic to be studied, the subjects and the type of study design. In this context, the researcher must determine how many subjects would be required for the proposed study. Thus, the number of individuals to be included in the study, i.e., the sample size is an important consideration in the design of many clinical studies. The sample size determination should be based on the difference in the outcome between the two groups studied as in an analytical study, as well as on the accepted p value for statistical significance and the required statistical power to test a hypothesis. The accepted risk of type I error or alpha value, which by convention is set at the 0.05 level in biomedical research defines the cutoff point at which the p value obtained in the study is judged as significant or not. The power in clinical research is the likelihood of finding a statistically significant result when it exists and is typically set to >80%. This is necessary since the most rigorously executed studies may fail to answer the research question if the sample size is too small. Alternatively, a study with too large a sample size will be difficult and will result in waste of time and resources. Thus, the goal of sample size planning is to estimate an appropriate number of subjects for a given study design. This article describes the concepts in estimating the sample size.

  1. Impacts of suppression on emotional responses and performance outcomes: an experience-sampling study in younger and older workers.

    Science.gov (United States)

    Yeung, Dannii Y; Fung, Helene H

    2012-11-01

    Past studies have demonstrated that older adults used less emotional suppression to regulate their emotions than did younger adults, but the effectiveness of using this emotion regulatory strategy on psychosocial well-being across age remains largely unexplored. The present study adopted an experience-sampling method to examine whether the impacts of momentary employment of emotional suppression on momentary positive and negative emotions and job performance would be different by age. Eighty-seven Chinese insurance workers, aged between 18 and 61 years, participated in a 5-day sampling study. Their affective responses at work, momentary task performance, and sales productivity were recorded. Results showed that older workers' greater use of suppression at work was associated with lower intensity of negative emotions, whereas such association was not found among younger workers. Moreover, greater use of suppression over the sampling period was significantly predictive of sales productivity of older workers, but such a positive association was not shown in younger workers. These findings reveal that the use of suppression at work may be more effective for older workers than for younger workers.

  2. Early Educational Intervention, Early Cumulative Risk, and the Early Home Environment as Predictors of Young Adult Outcomes within a High-Risk Sample

    Science.gov (United States)

    Pungello, Elizabeth P.; Kainz, Kirsten; Burchinal, Margaret; Wasik, Barbara H.; Sparling, Joseph J.; Ramey, Craig T.; Campbell, Frances A.

    2010-01-01

    The extent to which early educational intervention, early cumulative risk, and the early home environment were associated with young adult outcomes was investigated in a sample of 139 young adults (age 21) from high-risk families enrolled in randomized trials of early intervention. Positive effects of treatment were found for education attainment,…

  3. Prevalence and Mental Health Outcomes of Homicide Survivors in a Representative US Sample of Adolescents: Data from the 2005 National Survey of Adolescents

    Science.gov (United States)

    Rheingold, Alyssa A.; Zinzow, Heidi; Hawkins, Alesia; Saunders, Benjamin E.; Kilpatrick, Dean G.

    2012-01-01

    Background: Each homicide leaves behind several friends and family members, or homicide survivors. However, limited information is available on the impact of homicide on adolescent survivors. The purpose of the current study was to identify the prevalence of homicide survivorship and to determine mental health outcomes within a sample of US…

  4. Systematic sampling for suspended sediment

    Science.gov (United States)

    Robert B. Thomas

    1991-01-01

    Abstract - Because of high costs or complex logistics, scientific populations cannot be measured entirely and must be sampled. Accepted scientific practice holds that sample selection be based on statistical principles to assure objectivity when estimating totals and variances. Probability sampling--obtaining samples with known probabilities--is the only method that...

  5. Sampling Operations on Big Data

    Science.gov (United States)

    2015-11-29

    gories. These include edge sampling methods where edges are selected by a predetermined criteria; snowball sampling methods where algorithms start... Sampling Operations on Big Data Vijay Gadepally, Taylor Herr, Luke Johnson, Lauren Milechin, Maja Milosavljevic, Benjamin A. Miller Lincoln...process and disseminate information for discovery and exploration under real-time constraints. Common signal processing operations such as sampling and

  6. Standard methods for sampling and sample preparation for gamma spectroscopy

    International Nuclear Information System (INIS)

    Taskaeva, M.; Taskaev, E.; Nikolov, P.

    1993-01-01

    The strategy for sampling and sample preparation is outlined: necessary number of samples; analysis and treatment of the results received; quantity of the analysed material according to the radionuclide concentrations and analytical methods; the minimal quantity and kind of the data needed for making final conclusions and decisions on the base of the results received. This strategy was tested in gamma spectroscopic analysis of radionuclide contamination of the region of Eleshnitsa Uranium Mines. The water samples was taken and stored according to the ASTM D 3370-82. The general sampling procedures were in conformity with the recommendations of ISO 5667. The radionuclides was concentrated by coprecipitation with iron hydroxide and ion exchange. The sampling of soil samples complied with the rules of ASTM C 998, and their sample preparation - with ASTM C 999. After preparation the samples were sealed hermetically and measured. (author)

  7. Jenis Sample: Keuntungan dan Kerugiannya

    OpenAIRE

    Suprapto, Agus

    1994-01-01

    Sample is a part of a population that are used in a study for purposes of making estimation about the nature of the total population that is obtained with sampling technic. Sampling technic is more adventagous than cencus because it can reduce cost, time, and it can gather deeper information and more accurate data. It is useful to distinguish two major types of sampling technics. First, Prob bility sampling i.e. simple random sampling. Second, Non Probability sampling i.e. systematic sam­plin...

  8. Groundwater sampling in uranium reconnaissance

    International Nuclear Information System (INIS)

    Butz, T.R.

    1977-03-01

    The groundwater sampling program is based on the premise that ground water geochemistry reflects the chemical composition of, and geochemical processes active in the strata from which the sample is obtained. Pilot surveys have shown that wells are the best source of groundwater, although springs are sampled on occasion. The procedures followed in selecting a sampling site, the sampling itself, and the field measurements, as well as the site records made, are described

  9. Coordination of Conditional Poisson Samples

    Directory of Open Access Journals (Sweden)

    Grafström Anton

    2015-12-01

    Full Text Available Sample coordination seeks to maximize or to minimize the overlap of two or more samples. The former is known as positive coordination, and the latter as negative coordination. Positive coordination is mainly used for estimation purposes and to reduce data collection costs. Negative coordination is mainly performed to diminish the response burden of the sampled units. Poisson sampling design with permanent random numbers provides an optimum coordination degree of two or more samples. The size of a Poisson sample is, however, random. Conditional Poisson (CP sampling is a modification of the classical Poisson sampling that produces a fixed-size πps sample. We introduce two methods to coordinate Conditional Poisson samples over time or simultaneously. The first one uses permanent random numbers and the list-sequential implementation of CP sampling. The second method uses a CP sample in the first selection and provides an approximate one in the second selection because the prescribed inclusion probabilities are not respected exactly. The methods are evaluated using the size of the expected sample overlap, and are compared with their competitors using Monte Carlo simulation. The new methods provide a good coordination degree of two samples, close to the performance of Poisson sampling with permanent random numbers.

  10. Sample Transport for a European Sample Curation Facility

    Science.gov (United States)

    Berthoud, L.; Vrublevskis, J. B.; Bennett, A.; Pottage, T.; Bridges, J. C.; Holt, J. M. C.; Dirri, F.; Longobardo, A.; Palomba, E.; Russell, S.; Smith, C.

    2018-04-01

    This work has looked at the recovery of Mars Sample Return capsule once it arrives on Earth. It covers possible landing sites, planetary protection requirements, and transportation from the landing site to a European Sample Curation Facility.

  11. Sample Acquisition for Materials in Planetary Exploration (SAMPLE), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to analyze, design, and develop a device for autonomous lunar surface/subsurface sampling and processing applications. The Sample Acquisition for...

  12. Water born pollutants sampling using porous suction samples

    International Nuclear Information System (INIS)

    Baig, M.A.

    1997-01-01

    The common standard method of sampling water born pollutants in the vadoze zone is core sampling and it is followed by extraction of pore fluid. This method does not allow sampling at the same location next time and again later on. There is an alternative approach for sampling fluids (water born pollutants) from both saturated and unsaturated regions of vadose zone using porous suction samplers. There are three types of porous suction samplers, vacuum-operated, pressure-vacuum lysimeters, high pressure vacuum samples. The suction samples are operated in the range of 0-70 centi bars and usually consist of ceramic and polytetrafluorethylene (PTFE). The operation range of PTFE is higher than ceramic cups. These samplers are well suited for in situ and repeated sampling form the same location. This paper discusses the physical properties and operating condition of such samplers to the utilized under our environmental sampling. (author)

  13. Choosing a suitable sample size in descriptive sampling

    International Nuclear Information System (INIS)

    Lee, Yong Kyun; Choi, Dong Hoon; Cha, Kyung Joon

    2010-01-01

    Descriptive sampling (DS) is an alternative to crude Monte Carlo sampling (CMCS) in finding solutions to structural reliability problems. It is known to be an effective sampling method in approximating the distribution of a random variable because it uses the deterministic selection of sample values and their random permutation,. However, because this method is difficult to apply to complex simulations, the sample size is occasionally determined without thorough consideration. Input sample variability may cause the sample size to change between runs, leading to poor simulation results. This paper proposes a numerical method for choosing a suitable sample size for use in DS. Using this method, one can estimate a more accurate probability of failure in a reliability problem while running a minimal number of simulations. The method is then applied to several examples and compared with CMCS and conventional DS to validate its usefulness and efficiency

  14. Respondent-Driven Sampling – Testing Assumptions: Sampling with Replacement

    Directory of Open Access Journals (Sweden)

    Barash Vladimir D.

    2016-03-01

    Full Text Available Classical Respondent-Driven Sampling (RDS estimators are based on a Markov Process model in which sampling occurs with replacement. Given that respondents generally cannot be interviewed more than once, this assumption is counterfactual. We join recent work by Gile and Handcock in exploring the implications of the sampling-with-replacement assumption for bias of RDS estimators. We differ from previous studies in examining a wider range of sampling fractions and in using not only simulations but also formal proofs. One key finding is that RDS estimates are surprisingly stable even in the presence of substantial sampling fractions. Our analyses show that the sampling-with-replacement assumption is a minor contributor to bias for sampling fractions under 40%, and bias is negligible for the 20% or smaller sampling fractions typical of field applications of RDS.

  15. Sampling and chemical analysis in environmental samples around Nuclear Power Plants and some environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Woo; Han, Man Jung; Cho, Seong Won; Cho, Hong Jun; Oh, Hyeon Kyun; Lee, Jeong Min; Chang, Jae Sook [KORTIC, Taejon (Korea, Republic of)

    2002-12-15

    Twelve kinds of environmental samples such as soil, seawater, underground water, etc. around Nuclear Power Plants(NPPs) were collected. Tritium chemical analysis was tried for the samples of rain water, pine-needle, air, seawater, underground water, chinese cabbage, a grain of rice and milk sampled around NPPs, and surface seawater and rain water sampled over the country. Strontium in the soil that sere sampled at 60 point of district in Korea were analyzed. Tritium were sampled at 60 point of district in Korea were analyzed. Tritium were analyzed in 21 samples of surface seawater around the Korea peninsular that were supplied from KFRDI(National Fisheries Research and Development Institute). Sampling and chemical analysis environmental samples around Kori, Woolsung, Youngkwang, Wooljin Npps and Taeduk science town for tritium and strontium analysis was managed according to plans. Succeed to KINS after all samples were tried.

  16. A Note on Information-Directed Sampling and Thompson Sampling

    OpenAIRE

    Zhou, Li

    2015-01-01

    This note introduce three Bayesian style Multi-armed bandit algorithms: Information-directed sampling, Thompson Sampling and Generalized Thompson Sampling. The goal is to give an intuitive explanation for these three algorithms and their regret bounds, and provide some derivations that are omitted in the original papers.

  17. Sample summary report for KOR1 pressure tube sample

    International Nuclear Information System (INIS)

    Lee, Hee Jong; Nam, Min Woo; Choi, Young Ha

    2006-01-01

    This summary report includes basically the following: - The FLAW CHARACTERIZATION TABLE of KOR1 sample and supporting documentation. - The CROSS REFERENCE TABLES for each investigator, which is the SAMPLE INSPECTION TABLE that cross reference to the FLAW CHARACTERIZATION TABLE. - Each Sample Inspection Report as Appendices

  18. Specified assurance level sampling procedure

    International Nuclear Information System (INIS)

    Willner, O.

    1980-11-01

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

  19. A method of language sampling

    DEFF Research Database (Denmark)

    Rijkhoff, Jan; Bakker, Dik; Hengeveld, Kees

    1993-01-01

    In recent years more attention is paid to the quality of language samples in typological work. Without an adequate sampling strategy, samples may suffer from various kinds of bias. In this article we propose a sampling method in which the genetic criterion is taken as the most important: samples...... created with this method will reflect optimally the diversity of the languages of the world. On the basis of the internal structure of each genetic language tree a measure is computed that reflects the linguistic diversity in the language families represented by these trees. This measure is used...... to determine how many languages from each phylum should be selected, given any required sample size....

  20. Sample preparation in foodomic analyses.

    Science.gov (United States)

    Martinović, Tamara; Šrajer Gajdošik, Martina; Josić, Djuro

    2018-04-16

    Representative sampling and adequate sample preparation are key factors for successful performance of further steps in foodomic analyses, as well as for correct data interpretation. Incorrect sampling and improper sample preparation can be sources of severe bias in foodomic analyses. It is well known that both wrong sampling and sample treatment cannot be corrected anymore. These, in the past frequently neglected facts, are now taken into consideration, and the progress in sampling and sample preparation in foodomics is reviewed here. We report the use of highly sophisticated instruments for both high-performance and high-throughput analyses, as well as miniaturization and the use of laboratory robotics in metabolomics, proteomics, peptidomics and genomics. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  1. Sampling and estimating recreational use.

    Science.gov (United States)

    Timothy G. Gregoire; Gregory J. Buhyoff

    1999-01-01

    Probability sampling methods applicable to estimate recreational use are presented. Both single- and multiple-access recreation sites are considered. One- and two-stage sampling methods are presented. Estimation of recreational use is presented in a series of examples.

  2. Unit 06 - Sampling the World

    OpenAIRE

    Unit 06, CC in GIS; Parson, Charles; Nyerges, Timothy

    1990-01-01

    This unit begins the section on data acquisition by looking at how the infinite complexity of the real world can be discretized and sampled. It considers sampling techniques and associated issues of accuracy and standards.

  3. Public Use Microdata Samples (PUMS)

    Data.gov (United States)

    National Aeronautics and Space Administration — Public Use Microdata Samples (PUMS) are computer-accessible files containing records for a sample of housing units, with information on the characteristics of each...

  4. Soil sampling in emergency situations

    International Nuclear Information System (INIS)

    Carvalho, Zenildo Lara de; Ramos Junior, Anthenor Costa

    1997-01-01

    The soil sampling methods used in Goiania's accident (1987) by the environmental team of Brazilian Nuclear Energy Commission (CNEN) are described. The development of this method of soil sampling to a emergency sampling method used in a Nuclear Emergency Exercise in Angra dos Reis Reactor Site (1991) is presented. A new method for soil sampling based on a Chernobyl environmental monitoring experience (1995) is suggested. (author)

  5. Validating Multidimensional Outcome Assessment Using the TBI Common Data Elements: An Analysis of the TRACK-TBI Pilot Sample.

    Science.gov (United States)

    Nelson, Lindsay D; Ranson, Jana; Ferguson, Adam R; Giacino, Joseph; Okonkwo, David O; Valadka, Alex; Manley, Geoffrey; McCrea, Michael

    2017-06-08

    The Glasgow Outcome Scale-Extended (GOSE) is often the primary outcome measure in clinical trials for traumatic brain injury (TBI). Although the GOSE's capture of global function outcome has several strengths, concerns have been raised about its limited ability to identify mild disability and failure to capture the full scope of problems patients exhibit after TBI. This analysis examined the convergence of disability ratings across a multidimensional set of outcome domains in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Pilot study. The study collected measures recommended by the TBI Common Data Elements (CDE) Workgroup. Patients presenting to 3 emergency departments with a TBI of any severity enrolled in TRACK-TBI prospectively after injury; outcome measures were collected at 3 and six months postinjury. Analyses examined frequency of impairment and overlap between impairment status across the CDE outcome domains of Global Level of Functioning (GOSE), Neuropsychological (cognitive) Impairment, Psychological Status, TBI Symptoms, and Quality of Life. GOSE score correlated in the expected direction with other outcomes (M Spearman's rho = .21 and .49 with neurocognitive and self-report outcomes, respectively). The subsample in the Upper Good Recovery (GOSE 8) category appeared quite healthy across most other outcomes, although 19.0% had impaired executive functioning (Trail Making Test Part B). A significant minority of participants in the Lower Good Recovery subgroup (GOSE 7) met criteria for impairment across numerous other outcome measures. The findings highlight the multidimensional nature of TBI recovery and the limitations of applying only a single outcome measure.

  6. Patient identification in blood sampling.

    Science.gov (United States)

    Davidson, Anne; Bolton-Maggs, Paula

    The majority of adverse reports relating to blood transfusions result from human error, including misidentification of patients and incorrect labelling of samples. This article outlines best practice in blood sampling for transfusion (but is recommended for all pathology samples) and the role of patient empowerment in improving safety.

  7. Mars Sample Return Architecture Overview

    Science.gov (United States)

    Edwards, C. D.; Vijendran, S.

    2018-04-01

    NASA and ESA are exploring potential concepts for a Sample Retrieval Lander and Earth Return Orbiter that could return samples planned to be collected and cached by the Mars 2020 rover mission. We provide an overview of the Mars Sample Return architecture.

  8. The rise of survey sampling

    NARCIS (Netherlands)

    Bethlehem, J.

    2009-01-01

    This paper is about the history of survey sampling. It describes how sampling became an accepted scientific method. From the first ideas in 1895 it took some 50 years before the principles of probability sampling were widely accepted. This papers has a focus on developments in official statistics in

  9. Continuity, psychosocial correlates, and outcome of problematic substance use from adolescence to young adulthood in a community sample

    Directory of Open Access Journals (Sweden)

    Metzke Christa

    2007-10-01

    Full Text Available Abstract Background The study of the continuity, psychosocial correlates, and prediction of problematic substance use (PSU across time from adolescence to young adulthood. Methods Substance use was studied in a cohort of N = 593 subjects who had been assessed at three times between adolescence and young adulthood within the Zurich Psychology and Psychopathology Study (ZAPPS. Based on the frequency of tobacco, alcohol, and cannabis consumption, groups with PSU were defined at each of the three measurement points in time and compared to the rest of the sample. Comparisons included questionnaire data regarding emotional and behavioural problems, life events, coping style, self-related cognitions, perceived parenting style, perceived school environment, and size and efficiency of the social network. Results The size of the groups with PSU increased continuously across time. The cross-sectional correlates of PSU were characterized by a similar pattern that included higher scores for externalizing behaviour, and both number and negative impact of life events across all three times. At time 1 and 2 subjects with PSU also experienced less favourable parenting styles and school environments. Longitudinally, PSU in young adulthood was predicted most strongly and persistently by previous risk status, externalizing problems and male gender. Conclusion Problematic substance use is a major problem in youth. Its contributing pattern of associated and predictive psychosocial variables can be identified in the community.

  10. Continuity, psychosocial correlates, and outcome of problematic substance use from adolescence to young adulthood in a community sample.

    Science.gov (United States)

    Steinhausen, Hans-Christoph; Eschmann, Susanne; Metzke, Christa Winkler

    2007-10-11

    The study of the continuity, psychosocial correlates, and prediction of problematic substance use (PSU) across time from adolescence to young adulthood. Substance use was studied in a cohort of N = 593 subjects who had been assessed at three times between adolescence and young adulthood within the Zurich Psychology and Psychopathology Study (ZAPPS). Based on the frequency of tobacco, alcohol, and cannabis consumption, groups with PSU were defined at each of the three measurement points in time and compared to the rest of the sample. Comparisons included questionnaire data regarding emotional and behavioural problems, life events, coping style, self-related cognitions, perceived parenting style, perceived school environment, and size and efficiency of the social network. The size of the groups with PSU increased continuously across time. The cross-sectional correlates of PSU were characterized by a similar pattern that included higher scores for externalizing behaviour, and both number and negative impact of life events across all three times. At time 1 and 2 subjects with PSU also experienced less favourable parenting styles and school environments. Longitudinally, PSU in young adulthood was predicted most strongly and persistently by previous risk status, externalizing problems and male gender. Problematic substance use is a major problem in youth. Its contributing pattern of associated and predictive psychosocial variables can be identified in the community.

  11. Understanding reasons for and outcomes of patients lost to follow-up in antiretroviral therapy programs in Africa through a sampling-based approach.

    Science.gov (United States)

    Geng, Elvin H; Bangsberg, David R; Musinguzi, Nicolas; Emenyonu, Nneka; Bwana, Mwebesa Bosco; Yiannoutsos, Constantin T; Glidden, David V; Deeks, Steven G; Martin, Jeffrey N

    2010-03-01

    Losses to follow-up after initiation of antiretroviral therapy (ART) are common in Africa and are a considerable obstacle to understanding the effectiveness of nascent treatment programs. We sought to characterize, through a sampling-based approach, reasons for and outcomes of patients who become lost to follow-up. Cohort study. We searched for and interviewed a representative sample of lost patients or close informants in the community to determine reasons for and outcomes among lost patients. Three thousand six hundred twenty-eight HIV-infected adults initiated ART between January 1, 2004 and September 30, 2007 in Mbarara, Uganda. Eight hundred twenty-nine became lost to follow-up (cumulative incidence at 1, 2, and 3 years of 16%, 30%, and 39%). We sought a representative sample of 128 lost patients in the community and ascertained vital status in 111 (87%). Top reasons for loss included lack of transportation or money and work/child care responsibilities. Among the 111 lost patients who had their vital status ascertained through tracking, 32 deaths occurred (cumulative 1-year incidence 36%); mortality was highest shortly after the last clinic visit. Lower pre-ART CD4 T-cell count, older age, low blood pressure, and a central nervous system syndrome at the last clinic visit predicted deaths. Of patients directly interviewed, 83% were in care at another clinic and 71% were still using ART. Sociostructural factors are the primary reasons for loss to follow-up. Outcomes among the lost are heterogeneous: both deaths and transfers to other clinics were common. Tracking a sample of lost patients is an efficient means for programs to understand site-specific reasons for and outcomes among patients lost to follow-up.

  12. Sampling and sample processing in pesticide residue analysis.

    Science.gov (United States)

    Lehotay, Steven J; Cook, Jo Marie

    2015-05-13

    Proper sampling and sample processing in pesticide residue analysis of food and soil have always been essential to obtain accurate results, but the subject is becoming a greater concern as approximately 100 mg test portions are being analyzed with automated high-throughput analytical methods by agrochemical industry and contract laboratories. As global food trade and the importance of monitoring increase, the food industry and regulatory laboratories are also considering miniaturized high-throughput methods. In conjunction with a summary of the symposium "Residues in Food and Feed - Going from Macro to Micro: The Future of Sample Processing in Residue Analytical Methods" held at the 13th IUPAC International Congress of Pesticide Chemistry, this is an opportune time to review sampling theory and sample processing for pesticide residue analysis. If collected samples and test portions do not adequately represent the actual lot from which they came and provide meaningful results, then all costs, time, and efforts involved in implementing programs using sophisticated analytical instruments and techniques are wasted and can actually yield misleading results. This paper is designed to briefly review the often-neglected but crucial topic of sample collection and processing and put the issue into perspective for the future of pesticide residue analysis. It also emphasizes that analysts should demonstrate the validity of their sample processing approaches for the analytes/matrices of interest and encourages further studies on sampling and sample mass reduction to produce a test portion.

  13. Wideband 4-diode sampling circuit

    Science.gov (United States)

    Wojtulewicz, Andrzej; Radtke, Maciej

    2016-09-01

    The objective of this work was to develop a wide-band sampling circuit. The device should have the ability to collect samples of a very fast signal applied to its input, strengthen it and prepare for further processing. The study emphasizes the method of sampling pulse shaping. The use of ultrafast pulse generator allows sampling signals with a wide frequency spectrum, reaching several gigahertzes. The device uses a pulse transformer to prepare symmetrical pulses. Their final shape is formed with the help of the step recovery diode, two coplanar strips and Schottky diode. Made device can be used in the sampling oscilloscope, as well as other measurement system.

  14. Automatic sample changers maintenance manual

    International Nuclear Information System (INIS)

    Myers, T.A.

    1978-10-01

    This manual describes and provides trouble-shooting aids for the Automatic Sample Changer electronics on the automatic beta counting system, developed by the Los Alamos Scientific Laboratory Group CNC-11. The output of a gas detector is shaped by a preamplifier, then is coupled to an amplifier. Amplifier output is discriminated and is the input to a scaler. An identification number is associated with each sample. At a predetermined count length, the identification number, scaler data plus other information is punched out on a data card. The next sample to be counted is automatically selected. The beta counter uses the same electronics as the prior count did, the only difference being the sample identification number and sample itself. This manual is intended as a step-by-step aid in trouble-shooting the electronics associated with positioning the sample, counting the sample, and getting the needed data punched on an 80-column data card

  15. Manual versus automated blood sampling

    DEFF Research Database (Denmark)

    Teilmann, A C; Kalliokoski, Otto; Sørensen, Dorte B

    2014-01-01

    Facial vein (cheek blood) and caudal vein (tail blood) phlebotomy are two commonly used techniques for obtaining blood samples from laboratory mice, while automated blood sampling through a permanent catheter is a relatively new technique in mice. The present study compared physiological parameters......, glucocorticoid dynamics as well as the behavior of mice sampled repeatedly for 24 h by cheek blood, tail blood or automated blood sampling from the carotid artery. Mice subjected to cheek blood sampling lost significantly more body weight, had elevated levels of plasma corticosterone, excreted more fecal...... corticosterone metabolites, and expressed more anxious behavior than did the mice of the other groups. Plasma corticosterone levels of mice subjected to tail blood sampling were also elevated, although less significantly. Mice subjected to automated blood sampling were less affected with regard to the parameters...

  16. Pierre Gy's sampling theory and sampling practice heterogeneity, sampling correctness, and statistical process control

    CERN Document Server

    Pitard, Francis F

    1993-01-01

    Pierre Gy's Sampling Theory and Sampling Practice, Second Edition is a concise, step-by-step guide for process variability management and methods. Updated and expanded, this new edition provides a comprehensive study of heterogeneity, covering the basic principles of sampling theory and its various applications. It presents many practical examples to allow readers to select appropriate sampling protocols and assess the validity of sampling protocols from others. The variability of dynamic process streams using variography is discussed to help bridge sampling theory with statistical process control. Many descriptions of good sampling devices, as well as descriptions of poor ones, are featured to educate readers on what to look for when purchasing sampling systems. The book uses its accessible, tutorial style to focus on professional selection and use of methods. The book will be a valuable guide for mineral processing engineers; metallurgists; geologists; miners; chemists; environmental scientists; and practit...

  17. Sample representativeness verification of the FADN CZ farm business sample

    Directory of Open Access Journals (Sweden)

    Marie Prášilová

    2011-01-01

    Full Text Available Sample representativeness verification is one of the key stages of statistical work. After having joined the European Union the Czech Republic joined also the Farm Accountancy Data Network system of the Union. This is a sample of bodies and companies doing business in agriculture. Detailed production and economic data on the results of farming business are collected from that sample annually and results for the entire population of the country´s farms are then estimated and assessed. It is important hence, that the sample be representative. Representativeness is to be assessed as to the number of farms included in the survey and also as to the degree of accordance of the measures and indices as related to the population. The paper deals with the special statistical techniques and methods of the FADN CZ sample representativeness verification including the necessary sample size statement procedure. The Czech farm population data have been obtained from the Czech Statistical Office data bank.

  18. Pre-adult versus adult onset major depressive disorder in a naturalistic patient sample: the Leiden Routine Outcome Monitoring Study.

    Science.gov (United States)

    van Noorden, M S; Minkenberg, S E; Giltay, E J; den Hollander-Gijsman, M E; van Rood, Y R; van der Wee, N J; Zitman, F G

    2011-07-01

    Pre-adult onset of major depressive disorder (MDD) may predict a more severe phenotype of depression. As data from naturalistic psychiatric specialty care settings are scarce, we examined phenotypic differences between pre-adult and adult onset MDD in a large sample of consecutive out-patients. Altogether, 1552 out-patients, mean age 39.2 ± 11.6 years, were diagnosed with current MDD on the Mini-International Neuropsychiatric Interview Plus diagnostic interview as part of the usual diagnostic procedure. A total of 1105 patients (71.2%) had complete data on all variables of interest. Pre-adult onset of MDD was defined as having experienced the signs and symptoms of a first major depressive episode before the age of 18 years. Patients were stratified according to the age at interview (20-40/40-65 years). Correlates of pre-adult onset were analysed using logistic regression models adjusted for age, age squared and gender. Univariate analyses showed that pre-adult onset of MDD had a distinct set of demographic (e.g. less frequently living alone) and clinical correlates (more co-morbid DSM-IV - Text Revision diagnoses, more social phobia, more suicidality). In the multivariate model, we found an independent association only for a history of suicide attempts [odds ratio (OR) 3.15, 95% confidence intervals (CI) 1.97-5.05] and current suicidal thoughts (OR 1.81, 95% CI 1.26-2.60) in patients with pre-adult versus adult onset MDD. Pre-adult onset of MDD is associated with more suicidality than adult onset MDD. Age of onset of depression is an easy to ascertain characteristic that may help clinicians in weighing suicide risk.

  19. Sample summary report for ARG 1 pressure tube sample

    International Nuclear Information System (INIS)

    Belinco, C.

    2006-01-01

    The ARG 1 sample is made from an un-irradiated Zr-2.5% Nb pressure tube. The sample has 103.4 mm ID, 112 mm OD and approximately 500 mm length. A punch mark was made very close to one end of the sample. The punch mark indicates the 12 O'clock position and also identifies the face of the tube for making all the measurements. ARG 1 sample contains flaws on ID and OD surface. There was no intentional flaw within the wall of the pressure tube sample. Once the flaws are machined the pressure tube sample was covered from outside to hide the OD flaws. Approximately 50 mm length of pressure tube was left open at both the ends to facilitate the holding of sample in the fixtures for inspection. No flaw was machined in this zone of 50 mm on either end of the pressure tube sample. A total of 20 flaws were machined in ARG 1 sample. Out of these, 16 flaws were on the OD surface and the remaining 4 on the ID surface of the pressure tube. The flaws were characterized in to various groups like axial flaws, circumferential flaws, etc

  20. Comet coma sample return instrument

    Science.gov (United States)

    Albee, A. L.; Brownlee, Don E.; Burnett, Donald S.; Tsou, Peter; Uesugi, K. T.

    1994-01-01

    The sample collection technology and instrument concept for the Sample of Comet Coma Earth Return Mission (SOCCER) are described. The scientific goals of this Flyby Sample Return are to return to coma dust and volatile samples from a known comet source, which will permit accurate elemental and isotopic measurements for thousands of individual solid particles and volatiles, detailed analysis of the dust structure, morphology, and mineralogy of the intact samples, and identification of the biogenic elements or compounds in the solid and volatile samples. Having these intact samples, morphologic, petrographic, and phase structural features can be determined. Information on dust particle size, shape, and density can be ascertained by analyzing penetration holes and tracks in the capture medium. Time and spatial data of dust capture will provide understanding of the flux dynamics of the coma and the jets. Additional information will include the identification of cosmic ray tracks in the cometary grains, which can provide a particle's process history and perhaps even the age of the comet. The measurements will be made with the same equipment used for studying micrometeorites for decades past; hence, the results can be directly compared without extrapolation or modification. The data will provide a powerful and direct technique for comparing the cometary samples with all known types of meteorites and interplanetary dust. This sample collection system will provide the first sample return from a specifically identified primitive body and will allow, for the first time, a direct method of matching meteoritic materials captured on Earth with known parent bodies.

  1. Chorionic villus sampling and amniocentesis.

    Science.gov (United States)

    Brambati, Bruno; Tului, Lucia

    2005-04-01

    The advantages and disadvantages of common invasive methods for prenatal diagnosis are presented in light of new investigations. Several aspects of first-trimester chorionic villus sampling and mid-trimester amniocentesis remain controversial, especially fetal loss rate, feto-maternal complications, and the extension of both sampling methods to less traditional gestational ages (early amniocentesis, late chorionic villus sampling), all of which complicate genetic counseling. A recent randomized trial involving early amniocentesis and late chorionic villus sampling has confirmed previous studies, leading to the unquestionable conclusion that transabdominal chorionic villus sampling is safer. The old dispute over whether limb reduction defects are caused by chorionic villus sampling gains new vigor, with a paper suggesting that this technique has distinctive teratogenic effects. The large experience involving maternal and fetal complications following mid-trimester amniocentesis allows a better estimate of risk for comparison with chorionic villus sampling. Transabdominal chorionic villus sampling, which appears to be the gold standard sampling method for genetic investigations between 10 and 15 completed weeks, permits rapid diagnosis in high-risk cases detected by first-trimester screening of aneuploidies. Sampling efficiency and karyotyping reliability are as high as in mid-trimester amniocentesis with fewer complications, provided the operator has the required training, skill and experience.

  2. Air sampling in the workplace

    International Nuclear Information System (INIS)

    Hickey, E.E.; Stoetzel, G.A.; Strom, D.J.; Cicotte, G.R.; Wiblin, C.M.; McGuire, S.A.

    1993-09-01

    This report provides technical information on air sampling that will be useful for facilities following the recommendations in the NRC's Regulatory Guide 8.25, Revision 1, ''Air sampling in the Workplace.'' That guide addresses air sampling to meet the requirements in NRC's regulations on radiation protection, 10 CFR Part 20. This report describes how to determine the need for air sampling based on the amount of material in process modified by the type of material, release potential, and confinement of the material. The purposes of air sampling and how the purposes affect the types of air sampling provided are discussed. The report discusses how to locate air samplers to accurately determine the concentrations of airborne radioactive materials that workers will be exposed to. The need for and the methods of performing airflow pattern studies to improve the accuracy of air sampling results are included. The report presents and gives examples of several techniques that can be used to evaluate whether the airborne concentrations of material are representative of the air inhaled by workers. Methods to adjust derived air concentrations for particle size are described. Methods to calibrate for volume of air sampled and estimate the uncertainty in the volume of air sampled are described. Statistical tests for determining minimum detectable concentrations are presented. How to perform an annual evaluation of the adequacy of the air sampling is also discussed

  3. Optimization of sampling parameters for standardized exhaled breath sampling.

    Science.gov (United States)

    Doran, Sophie; Romano, Andrea; Hanna, George B

    2017-09-05

    The lack of standardization of breath sampling is a major contributing factor to the poor repeatability of results and hence represents a barrier to the adoption of breath tests in clinical practice. On-line and bag breath sampling have advantages but do not suit multicentre clinical studies whereas storage and robust transport are essential for the conduct of wide-scale studies. Several devices have been developed to control sampling parameters and to concentrate volatile organic compounds (VOCs) onto thermal desorption (TD) tubes and subsequently transport those tubes for laboratory analysis. We conducted three experiments to investigate (i) the fraction of breath sampled (whole vs. lower expiratory exhaled breath); (ii) breath sample volume (125, 250, 500 and 1000ml) and (iii) breath sample flow rate (400, 200, 100 and 50 ml/min). The target VOCs were acetone and potential volatile biomarkers for oesophago-gastric cancer belonging to the aldehyde, fatty acids and phenol chemical classes. We also examined the collection execution time and the impact of environmental contamination. The experiments showed that the use of exhaled breath-sampling devices requires the selection of optimum sampling parameters. The increase in sample volume has improved the levels of VOCs detected. However, the influence of the fraction of exhaled breath and the flow rate depends on the target VOCs measured. The concentration of potential volatile biomarkers for oesophago-gastric cancer was not significantly different between the whole and lower airway exhaled breath. While the recovery of phenols and acetone from TD tubes was lower when breath sampling was performed at a higher flow rate, other VOCs were not affected. A dedicated 'clean air supply' overcomes the contamination from ambient air, but the breath collection device itself can be a source of contaminants. In clinical studies using VOCs to diagnose gastro-oesophageal cancer, the optimum parameters are 500mls sample volume

  4. 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)

  5. Acceptance sampling using judgmental and randomly selected samples

    Energy Technology Data Exchange (ETDEWEB)

    Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

    2010-09-01

    We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

  6. Gravimetric dust sampling for control purposes and occupational dust sampling.

    CSIR Research Space (South Africa)

    Unsted, AD

    1997-02-01

    Full Text Available Prior to the introduction of gravimetric dust sampling, konimeters had been used for dust sampling, which was largely for control purposes. Whether or not absolute results were achievable was not an issue since relative results were used to evaluate...

  7. Evaluation of the Psychometric Properties of NOC Outcomes "Anxiety Level" and "Anxiety Self-Control" in a Portuguese Outpatient Sample.

    Science.gov (United States)

    Sampaio, Francisco Miguel Correia; Araújo, Odete Sofia Silva Lomba; Sequeira, Carlos Alberto da Cruz; Lluch Canut, María Teresa; Martins, Teresa

    2017-01-25

    To adopt the language and to evaluate the psychometric properties of "Anxiety level" and "Anxiety self-control" NOC outcomes in Portuguese adult patients. Methodological design. The final European Portuguese version of the NOC outcome "Anxiety level," composed by 16 indicators, proved excellent internal consistency. Exploratory factor analysis (EFA) was forced to three factors. The NOC outcome "Anxiety self-control," composed of nine indicators, demonstrated a questionable internal consistency. EFA was forced to two factors. European Portuguese versions of the studied NOC outcomes proved to be tools with acceptable psychometric properties for evaluating anxiety in Portuguese patients. This study contributed to the development of NOC language and to the enrichment of nursing's body of knowledge. Adaptar a linguagem e avaliar as propriedades psicométricas dos resultados NOC "Nível de ansiedade" e "Autocontrolo da ansiedade" em utentes portugueses adultos. MÉTODOS: Estudo metodológico. A versão portuguesa do resultado NOC "Nível de ansiedade", composta por 16 indicadores, apresentou uma excelente consistência interna. A análise fatorial exploratória (AFE) foi forçada a três dimensões. O resultado NOC "Autocontrolo da ansiedade", composto por nove indicadores, apresentou uma consistência interna questionável. A AFE foi forçada a duas dimensões. CONCLUSÕES: As versões portuguesas dos resultados NOC estudados são instrumentos com propriedades psicométricas aceitáveis para avaliar a ansiedade em utentes portugueses. IMPLICAÇÕES PARA A PRÁTICA DE ENFERMAGEM: Este estudo contribuiu para o desenvolvimento da linguagem NOC e para enriquecer o corpo de conhecimento de Enfermagem. © 2017 NANDA International, Inc.

  8. Utility of the Mayo-Portland adaptability inventory-4 for self-reported outcomes in a military sample with traumatic brain injury.

    Science.gov (United States)

    Kean, Jacob; Malec, James F; Cooper, Douglas B; Bowles, Amy O

    2013-12-01

    To investigate the psychometric properties of the Mayo-Portland Adaptability Inventory-4 (MPAI-4) obtained by self-report in a large sample of active duty military personnel with traumatic brain injury (TBI). Consecutive cohort who completed the MPAI-4 as a part of a larger battery of clinical outcome measures at the time of intake to an outpatient brain injury clinic. Medical center. Consecutively referred sample of active duty military personnel (N=404) who suffered predominantly mild (n=355), but also moderate (n=37) and severe (n=12), TBI. Not applicable. MPAI-4 RESULTS: Initial factor analysis suggested 2 salient dimensions. In subsequent analysis, the ratio of the first and second eigenvalues (6.84:1) and parallel analysis indicated sufficient unidimensionality in 26 retained items. Iterative Rasch analysis resulted in the rescaling of the measure and the removal of 5 additional items for poor fit. The items of the final 21-item Mayo-Portland Adaptability Inventory-military were locally independent, demonstrated monotonically increasing responses, adequately fit the item response model, and permitted the identification of nearly 5 statistically distinct levels of disability in the study population. Slight mistargeting of the population resulted in the global outcome, as measured by the Mayo-Portland Adaptability Inventory-military, tending to be less reflective of very mild levels of disability. These data collected in a relatively large sample of active duty service members with TBI provide insight into the ability of patients to self-report functional impairment and the distinct effects of military deployment on outcome, providing important guidance for the meaningful measurement of outcome in this population. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  9. PIXE analysis of thin samples

    International Nuclear Information System (INIS)

    Kiss, Ildiko; Koltay, Ede; Szabo, Gyula; Laszlo, S.; Meszaros, A.

    1985-01-01

    Particle-induced X-ray emission (PIXE) multielemental analysis of thin film samples are reported. Calibration methods of K and L X-lines are discussed. Application of PIXE analysis to aerosol monitoring, multielement aerosol analysis is described. Results of PIXE analysis of samples from two locations in Hungary are compared with the results of aerosol samples from Scandinavia and the USA. (D.Gy.)

  10. Environmental sampling for trace analysis

    International Nuclear Information System (INIS)

    Markert, B.

    1994-01-01

    Often too little attention is given to the sampling before and after actual instrumental measurement. This leads to errors, despite increasingly sensitive analytical systems. This is one of the first books to pay proper attention to representative sampling. It offers an overview of the most common techniques used today for taking environmental samples. The techniques are clearly presented, yield accurate and reproducible results and can be used to sample -air - water - soil and sediments - plants and animals. A comprehensive handbook, this volume provides an excellent starting point for researchers in the rapidly expanding field of environmental analysis. (orig.)

  11. Sample Preprocessing For Atomic Spectrometry

    International Nuclear Information System (INIS)

    Kim, Sun Tae

    2004-08-01

    This book gives descriptions of atomic spectrometry, which deals with atomic absorption spectrometry such as Maxwell-Boltzmann equation and Beer-Lambert law, atomic absorption spectrometry for solvent extraction, HGAAS, ETASS, and CVAAS and inductively coupled plasma emission spectrometer, such as basic principle, generative principle of plasma and device and equipment, and interferences, and inductively coupled plasma mass spectrometry like device, pros and cons of ICP/MS, sample analysis, reagent, water, acid, flux, materials of experiments, sample and sampling and disassembling of sample and pollution and loss in open system and closed system.

  12. Sample size adjustments for varying cluster sizes in cluster randomized trials with binary outcomes analyzed with second-order PQL mixed logistic regression.

    Science.gov (United States)

    Candel, Math J J M; Van Breukelen, Gerard J P

    2010-06-30

    Adjustments of sample size formulas are given for varying cluster sizes in cluster randomized trials with a binary outcome when testing the treatment effect with mixed effects logistic regression using second-order penalized quasi-likelihood estimation (PQL). Starting from first-order marginal quasi-likelihood (MQL) estimation of the treatment effect, the asymptotic relative efficiency of unequal versus equal cluster sizes is derived. A Monte Carlo simulation study shows this asymptotic relative efficiency to be rather accurate for realistic sample sizes, when employing second-order PQL. An approximate, simpler formula is presented to estimate the efficiency loss due to varying cluster sizes when planning a trial. In many cases sampling 14 per cent more clusters is sufficient to repair the efficiency loss due to varying cluster sizes. Since current closed-form formulas for sample size calculation are based on first-order MQL, planning a trial also requires a conversion factor to obtain the variance of the second-order PQL estimator. In a second Monte Carlo study, this conversion factor turned out to be 1.25 at most. (c) 2010 John Wiley & Sons, Ltd.

  13. The effects of positive and negative parenting practices on adolescent mental health outcomes in a multicultural sample of rural youth.

    Science.gov (United States)

    Smokowski, Paul R; Bacallao, Martica L; Cotter, Katie L; Evans, Caroline B R

    2015-06-01

    The quality of parent-child relationships has a significant impact on adolescent developmental outcomes, especially mental health. Given the lack of research on rural adolescent mental health in general and rural parent-child relationships in particular, the current longitudinal study explores how rural adolescents' (N = 2,617) perceptions of parenting practices effect their mental health (i.e., anxiety, depression, aggression, self-esteem, future optimism, and school satisfaction) over a 1 year period. Regression models showed that current parenting practices (i.e., in Year 2) were strongly associated with current adolescent mental health outcomes. Negative current parenting, manifesting in parent-adolescent conflict, was related to higher adolescent anxiety, depression, and aggression and lower self-esteem, and school satisfaction. Past parent-adolescent conflict (i.e., in Year 1) also positively predicted adolescent aggression in the present. Current positive parenting (i.e., parent support, parent-child future orientation, and parent education support) was significantly associated with less depression and higher self-esteem, future optimism, and school satisfaction. Past parent education support was also related to current adolescent future optimism. Implications for practice and limitations were discussed.

  14. Environmental surveillance master sampling schedule

    International Nuclear Information System (INIS)

    Bisping, L.E.

    1995-02-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the U.S. Department of Energy (DOE). This document contains the planned 1994 schedules for routine collection of samples for the Surface Environmental Surveillance Project (SESP), Drinking Water Project, and Ground-Water Surveillance Project. Samples are routinely collected for the SESP and analyzed to determine the quality of air, surface water, soil, sediment, wildlife, vegetation, foodstuffs, and farm products at Hanford Site and surrounding communities. The responsibility for monitoring onsite drinking water falls outside the scope of the SESP. PNL conducts the drinking water monitoring project concurrent with the SESP to promote efficiency and consistency, utilize expertise developed over the years, and reduce costs associated with management, procedure development, data management, quality control, and reporting. The ground-water sampling schedule identifies ground-water sampling .events used by PNL for environmental surveillance of the Hanford Site. Sampling is indicated as annual, semi-annual, quarterly, or monthly in the sampling schedule. Some samples are collected and analyzed as part of ground-water monitoring and characterization programs at Hanford (e.g. Resources Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), or Operational). The number of samples planned by other programs are identified in the sampling schedule by a number in the analysis column and a project designation in the Cosample column. Well sampling events may be merged to avoid redundancy in cases where sampling is planned by both-environmental surveillance and another program

  15. Environmental surveillance master sampling schedule

    Energy Technology Data Exchange (ETDEWEB)

    Bisping, L.E.

    1995-02-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the U.S. Department of Energy (DOE). This document contains the planned 1994 schedules for routine collection of samples for the Surface Environmental Surveillance Project (SESP), Drinking Water Project, and Ground-Water Surveillance Project. Samples are routinely collected for the SESP and analyzed to determine the quality of air, surface water, soil, sediment, wildlife, vegetation, foodstuffs, and farm products at Hanford Site and surrounding communities. The responsibility for monitoring onsite drinking water falls outside the scope of the SESP. PNL conducts the drinking water monitoring project concurrent with the SESP to promote efficiency and consistency, utilize expertise developed over the years, and reduce costs associated with management, procedure development, data management, quality control, and reporting. The ground-water sampling schedule identifies ground-water sampling .events used by PNL for environmental surveillance of the Hanford Site. Sampling is indicated as annual, semi-annual, quarterly, or monthly in the sampling schedule. Some samples are collected and analyzed as part of ground-water monitoring and characterization programs at Hanford (e.g. Resources Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), or Operational). The number of samples planned by other programs are identified in the sampling schedule by a number in the analysis column and a project designation in the Cosample column. Well sampling events may be merged to avoid redundancy in cases where sampling is planned by both-environmental surveillance and another program.

  16. 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

  17. Advanced pressure tube sampling tools

    International Nuclear Information System (INIS)

    Wittich, K.C.; King, J.M.

    2002-01-01

    Deuterium concentration is an important parameter that must be assessed to evaluate the Fitness for service of CANDU pressure tubes. In-reactor pressure tube sampling allows accurate deuterium concentration assessment to be made without the expenses associated with fuel channel removal. This technology, which AECL has developed over the past fifteen years, has become the standard method for deuterium concentration assessment. AECL is developing a multi-head tool that would reduce in-reactor handling overhead by allowing one tool to sequentially sample at all four axial pressure tube locations before removal from the reactor. Four sets of independent cutting heads, like those on the existing sampling tools, facilitate this incorporating proven technology demonstrated in over 1400 in-reactor samples taken to date. The multi-head tool is delivered by AECL's Advanced Delivery Machine or other similar delivery machines. Further, AECL has developed an automated sample handling system that receives and processes the tool once out of the reactor. This system retrieves samples from the tool, dries, weighs and places them in labelled vials which are then directed into shielded shipping flasks. The multi-head wet sampling tool and the automated sample handling system are based on proven technology and offer continued savings and dose reduction to utilities in a competitive electricity market. (author)

  18. Succinct Sampling from Discrete Distributions

    DEFF Research Database (Denmark)

    Bringmann, Karl; Larsen, Kasper Green

    2013-01-01

    We revisit the classic problem of sampling from a discrete distribution: Given n non-negative w-bit integers x_1,...,x_n, the task is to build a data structure that allows sampling i with probability proportional to x_i. The classic solution is Walker's alias method that takes, when implemented...

  19. Simulated Sampling of Estuary Plankton

    Science.gov (United States)

    Fortner, Rosanne W.; Jenkins, Deborah Bainer

    2009-01-01

    To find out about the microscopic life in the valuable estuary environment, it is usually necessary to be near the water. This dry lab offers an alternative, using authentic data and a simulation of plankton sampling. From the types of organisms found in the sample, middle school students can infer relationships in the biological and physical…

  20. Standard Deviation for Small Samples

    Science.gov (United States)

    Joarder, Anwar H.; Latif, Raja M.

    2006-01-01

    Neater representations for variance are given for small sample sizes, especially for 3 and 4. With these representations, variance can be calculated without a calculator if sample sizes are small and observations are integers, and an upper bound for the standard deviation is immediate. Accessible proofs of lower and upper bounds are presented for…

  1. Learning to reason from samples

    NARCIS (Netherlands)

    Ben-Zvi, Dani; Bakker, Arthur; Makar, Katie

    2015-01-01

    The goal of this article is to introduce the topic of learning to reason from samples, which is the focus of this special issue of Educational Studies in Mathematics on statistical reasoning. Samples are data sets, taken from some wider universe (e.g., a population or a process) using a particular

  2. SAMPLING IN EXTERNAL AUDIT - THE MONETARY UNIT SAMPLING METHOD

    Directory of Open Access Journals (Sweden)

    E. Dascalu

    2016-12-01

    Full Text Available This article approaches the general issue of diminishing the evidence investigation space in audit activities, by means of sampling techniques, given that in the instance of a significant data volume an exhaustive examination of the assessed popula¬tion is not possible and/or effective. The general perspective of the presentation involves dealing with sampling risk, in essence, the risk that a selected sample may not be representative for the overall population, in correlation with the audit risk model and with the component parts of this model (inherent risk, control risk and non detection risk and highlights the inter-conditionings between these two models.

  3. A simple vibrating sample magnetometer for macroscopic samples

    Science.gov (United States)

    Lopez-Dominguez, V.; Quesada, A.; Guzmán-Mínguez, J. C.; Moreno, L.; Lere, M.; Spottorno, J.; Giacomone, F.; Fernández, J. F.; Hernando, A.; García, M. A.

    2018-03-01

    We here present a simple model of a vibrating sample magnetometer (VSM). The system allows recording magnetization curves at room temperature with a resolution of the order of 0.01 emu and is appropriated for macroscopic samples. The setup can be mounted with different configurations depending on the requirements of the sample to be measured (mass, saturation magnetization, saturation field, etc.). We also include here examples of curves obtained with our setup and comparison curves measured with a standard commercial VSM that confirms the reliability of our device.

  4. Latent Class Analysis of Gambling Activities in a Sample of Young Swiss Men: Association with Gambling Problems, Substance Use Outcomes, Personality Traits and Coping Strategies.

    Science.gov (United States)

    Studer, Joseph; Baggio, Stéphanie; Mohler-Kuo, Meichun; Simon, Olivier; Daeppen, Jean-Bernard; Gmel, Gerhard

    2016-06-01

    The study aimed to identify different patterns of gambling activities (PGAs) and to investigate how PGAs differed in gambling problems, substance use outcomes, personality traits and coping strategies. A representative sample of 4989 young Swiss males completed a questionnaire assessing seven distinct gambling activities, gambling problems, substance use outcomes, personality traits and coping strategies. PGAs were identified using latent class analysis (LCA). Differences between PGAs in gambling and substance use outcomes, personality traits and coping strategies were tested. LCA identified six different PGAs. With regard to gambling and substance use outcomes, the three most problematic PGAs were extensive gamblers, followed by private gamblers, and electronic lottery and casino gamblers, respectively. By contrast, the three least detrimental PGAs were rare or non-gamblers, lottery only gamblers and casino gamblers. With regard to personality traits, compared with rare or non-gamblers, private and casino gamblers reported higher levels of sensation seeking. Electronic lottery and casino gamblers, private gamblers and extensive gamblers had higher levels of aggression-hostility. Extensive and casino gamblers reported higher levels of sociability, whereas casino gamblers reported lower levels of anxiety-neuroticism. Extensive gamblers used more maladaptive and less adaptive coping strategies than other groups. Results suggest that gambling is not a homogeneous activity since different types of gamblers exist according to the PGA they are engaged in. Extensive gamblers, electronic and casino gamblers and private gamblers may have the most problematic PGAs. Personality traits and coping skills may predispose individuals to PGAs associated with more or less negative outcomes.

  5. Mass counting of radioactivity samples

    International Nuclear Information System (INIS)

    Oesterlin, D.L.; Obrycki, R.F.

    1977-01-01

    A method and apparatus for concurrently counting a plurality of radioactive samples is claimed. The position sensitive circuitry of a scintillation camera is employed to sort electrical pulses resulting from scintillations according to the geometrical locations of scintillations causing those pulses. A scintillation means, in the form of a scintillating crystal material or a liquid scintillator, is positioned proximate to an array of radioactive samples. Improvement in the accuracy of pulse classification may be obtained by employing collimating means. If a plurality of scintillation crystals are employed to measure the iodine-125 content of samples, a method and means are provided for correcting for variations in crystal light transmission properties, sample volume, and sample container radiation absorption. 2 claims, 7 drawing figures

  6. Patient-reported outcome measures for patients with cerebral aneurysms acquired via social media: data from a large nationwide sample.

    Science.gov (United States)

    Chen, Michael; Mangubat, Erwin; Ouyang, Bichun

    2016-01-01

    With greater survival rates, patient-reported outcome measures (PROMs) among survivors of ruptured cerebral aneurysm should be an increasing concern among neurointerventionalists. Prior studies were limited in scale and generalizability. Our study aims were to (1) evaluate the validity of cerebral aneurysm PROMs obtained from social media; (2) determine the persistence of PROMs over time; and (3) determine what PROMs still exist in those with no physical impairments. By engaging national brain aneurysm support groups and using an online questionnaire modeled after the generic EQ-5D instrument, we asked respondents to classify their health in five dimensions including mobility, self-care, usual activities, pain/discomfort, and anxiety/depression using a 3-point Likert scale. In 2 months we received 604 responses from 46 states in the USA. Our cohort of ruptured aneurysm respondents reported PROMs similar to previously published series. Over time, headache and anxiety improved while depression, level of exercise, and return to work remained unchanged. We found that memory worsened after 2 years. Among those without any physical impairment, rates of 20.6%, 14.9%, 12.6%, and 23% were seen for significant headaches, significant memory loss, significant depression, and sense of life being negatively affected, respectively. Despite this novel study design, we obtained results comparable to prior studies. These results suggest that many patients with ruptured cerebral aneurysms, regardless of whether they are >2 years after the event and/or free of physical impairment, struggle with a poor quality of life. The latency, scale, and low cost of this study design may accelerate future cerebral aneurysm PROM research. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. The association between smoking and subsequent suicide-related outcomes in the National Comorbidity Survey panel sample.

    Science.gov (United States)

    Kessler, R C; Borges, G; Sampson, N; Miller, M; Nock, M K

    2009-12-01

    Controversy exists about whether the repeatedly documented associations between smoking and subsequent suicide-related outcomes (SROs; ideation, plans, gestures and attempts) are due to unmeasured common causes or to causal effects of smoking on SROs. We address this issue by examining associations of smoking with subsequent SROs with and without controls for potential explanatory variables in the National Comorbidity Survey (NCS) panel. The latter consists of 5001 people who participated in both the 1990-2002 NCS and the 2001-2003 NCS follow-up survey. Explanatory variables include sociodemographics, potential common causes (parental history of mental-substance disorders; other respondent childhood adversities) and potential mediators (respondent history of Diagnostic and Statistical Manual of Mental Disorders, 3rd edn, revised mental-substance disorders). Small gross (that is, without controls) prospective associations are found between history of early-onset nicotine dependence and both subsequent suicide ideation and, among ideators, subsequent suicide plans. None of the baseline smoking measures, though, predicts subsequent suicide gestures or attempts among ideators. The smoking-ideation association largely disappear, but the association of early-onset nicotine dependence with subsequent suicide plans persists (odds ratio=3.0), after adjustment for control variables. However, the latter association is as strong with remitted as active nicotine dependence, arguing against a direct causal effect of nicotine dependence on suicide plans. Decomposition of the control variable effects, furthermore, suggests that these effects are due to common causes more than to mediators. These results refine our understanding of the ways in which smoking is associated with later SROs and for the most part argue against the view that these associations are due to causal effects of smoking.

  8. Large sample neutron activation analysis of a reference inhomogeneous sample

    International Nuclear Information System (INIS)

    Vasilopoulou, T.; Athens National Technical University, Athens; Tzika, F.; Stamatelatos, I.E.; Koster-Ammerlaan, M.J.J.

    2011-01-01

    A benchmark experiment was performed for Neutron Activation Analysis (NAA) of a large inhomogeneous sample. The reference sample was developed in-house and consisted of SiO 2 matrix and an Al-Zn alloy 'inhomogeneity' body. Monte Carlo simulations were employed to derive appropriate correction factors for neutron self-shielding during irradiation as well as self-attenuation of gamma rays and sample geometry during counting. The large sample neutron activation analysis (LSNAA) results were compared against reference values and the trueness of the technique was evaluated. An agreement within ±10% was observed between LSNAA and reference elemental mass values, for all matrix and inhomogeneity elements except Samarium, provided that the inhomogeneity body was fully simulated. However, in cases that the inhomogeneity was treated as not known, the results showed a reasonable agreement for most matrix elements, while large discrepancies were observed for the inhomogeneity elements. This study provided a quantification of the uncertainties associated with inhomogeneity in large sample analysis and contributed to the identification of the needs for future development of LSNAA facilities for analysis of inhomogeneous samples. (author)

  9. The Predictive Role of Self-efficacy, Outcome Expectancies, Past Behavior and Attitudes on Condom Use in a Sample of Female College Students

    Directory of Open Access Journals (Sweden)

    Daniele Artistico

    2014-12-01

    Full Text Available This study investigated the impact of self-efficacy in relation to condom use. A sample of 87 female college students completed self-report measures related to their sexual history, attitudes towards condoms and past condom use, as well as their outcome expectancy and intention to use condoms in the future. The results showed a positive correlation between self-efficacy and positive attitudes towards condom use, as well as correlations between past behavior, self-efficacy and intention to use condoms in the future. Multiple linear regression models were used to further explore the relationship between self-efficacy, past condom use, outcome expectancy and attitudes toward condoms, with the intention to use condoms in the future. The results demonstrated that both self-efficacy and past condom use are significant predictors of an individual’s intention to use condoms in the future.

  10. Directional dependency of air sampling

    International Nuclear Information System (INIS)

    1994-01-01

    A field study was performed by Idaho State University-Environmental Monitoring Laboratory (EML) to examine the directional dependency of low-volume air samplers. A typical continuous low volume air sampler contains a sample head that is mounted on the sampler housing either horizontally through one of four walls or vertically on an exterior wall 'looking down or up.' In 1992, a field study was undertaken to estimate sampling error and to detect the directional effect of sampler head orientation. Approximately 1/2 mile downwind from a phosphate plant (continuous source of alpha activity), four samplers were positioned in identical orientation alongside one sampler configured with the sample head 'looking down'. At least five consecutive weekly samples were collected. The alpha activity, beta activity, and the Be-7 activity collected on the particulate filter were analyzed to determine sampling error. Four sample heads were than oriented to the four different horizontal directions. Samples were collected for at least five weeks. Analysis of the alpha data can show the effect of sampler orientation to a know near source term. Analysis of the beta and Be-7 activity shows the effect of sampler orientation to a ubiquitous source term

  11. Rapid Sampling from Sealed Containers

    International Nuclear Information System (INIS)

    Johnston, R.G.; Garcia, A.R.E.; Martinez, R.K.; Baca, E.T.

    1999-01-01

    The authors have developed several different types of tools for sampling from sealed containers. These tools allow the user to rapidly drill into a closed container, extract a sample of its contents (gas, liquid, or free-flowing powder), and permanently reseal the point of entry. This is accomplished without exposing the user or the environment to the container contents, even while drilling. The entire process is completed in less than 15 seconds for a 55 gallon drum. Almost any kind of container can be sampled (regardless of the materials) with wall thicknesses up to 1.3 cm and internal pressures up to 8 atm. Samples can be taken from the top, sides, or bottom of a container. The sampling tools are inexpensive, small, and easy to use. They work with any battery-powered hand drill. This allows considerable safety, speed, flexibility, and maneuverability. The tools also permit the user to rapidly attach plumbing, a pressure relief valve, alarms, or other instrumentation to a container. Possible applications include drum venting, liquid transfer, container flushing, waste characterization, monitoring, sampling for archival or quality control purposes, emergency sampling by rapid response teams, counter-terrorism, non-proliferation and treaty verification, and use by law enforcement personnel during drug or environmental raids

  12. Environmental surveillance master sampling schedule

    International Nuclear Information System (INIS)

    Bisping, L.E.

    1991-01-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). This document contains the planned schedule for routine sample collection for the Surface Environmental Surveillance Project (SESP) and Ground-Water Monitoring Project. The routine sampling plan for the SESP has been revised this year to reflect changing site operations and priorities. Some sampling previously performed at least annually has been reduced in frequency, and some new sampling to be performed at a less than annual frequency has been added. Therefore, the SESP schedule reflects sampling to be conducted in calendar year 1991 as well as future years. The ground-water sampling schedule is for 1991. This schedule is subject to modification during the year in response to changes in Site operation, program requirements, and the nature of the observed results. Operational limitations such as weather, mechanical failures, sample availability, etc., may also require schedule modifications. Changes will be documented in the respective project files, but this plan will not be reissued. The purpose of these monitoring projects is to evaluate levels of radioactive and nonradioactive pollutants in the Hanford evirons

  13. Environmental surveillance master sampling schedule

    Energy Technology Data Exchange (ETDEWEB)

    Bisping, L.E.

    1991-01-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). This document contains the planned schedule for routine sample collection for the Surface Environmental Surveillance Project (SESP) and Ground-Water Monitoring Project. The routine sampling plan for the SESP has been revised this year to reflect changing site operations and priorities. Some sampling previously performed at least annually has been reduced in frequency, and some new sampling to be performed at a less than annual frequency has been added. Therefore, the SESP schedule reflects sampling to be conducted in calendar year 1991 as well as future years. The ground-water sampling schedule is for 1991. This schedule is subject to modification during the year in response to changes in Site operation, program requirements, and the nature of the observed results. Operational limitations such as weather, mechanical failures, sample availability, etc., may also require schedule modifications. Changes will be documented in the respective project files, but this plan will not be reissued. The purpose of these monitoring projects is to evaluate levels of radioactive and nonradioactive pollutants in the Hanford evirons.

  14. Hungry to learn: the prevalence and effects of food insecurity on health behaviors and outcomes over time among a diverse sample of university freshmen.

    Science.gov (United States)

    Bruening, Meg; van Woerden, Irene; Todd, Michael; Laska, Melissa N

    2018-01-18

    To examine longitudinal associations between food insecurity (FI) and health behaviors/outcomes among a diverse sample of university freshmen. Freshman students (n = 1138; 65% female; 49% non-white) participating in the Social impact of Physical Activity and nutRition in College study completed surveys on health behaviors and had height/weight measured up to 4 times (T1-T4) in Arizona during 2015-2016. Structural equation models were estimated to determine if, after adjusting for covariates, FI predicted concurrent behaviors/outcomes and subsequent behaviors/outcomes. Analyses reported here were conducted in 2017. The prevalence of FI was significantly higher at the end of each semester (35% and 36%, respectively) than at the start of the year (28%). Longitudinally, FI was not related to any health behaviors/outcomes at future time points. However, FI was significantly and inversely associated with concurrent breakfast consumption on most days of the week (OR = 0.67, 99% CI = 0.46, 0.99), daily evening meal consumption (OR = 0.55, 99% CI = 0.36, 0.86) healthy eating habits on campus (OR = 0.68, 99% CI = 0.46, 1.00), healthy physical activity habits on campus (OR = 0.66, 99% CI = 0.44, 1.00), and positively related to the likelihood of experiencing stress (OR = 1.69, 99% CI = 1.16, 2.46) and depressed mood (OR = 1.98, 99% CI = 1.34, 2.91). Compared with US prevalence rates, the sample FI prevalence was high. FI was related to poorer eating patterns, physical activity behaviors, and mental health, even after adjusting for prior levels of behavior.

  15. Gleeble Testing of Tungsten Samples

    Science.gov (United States)

    2013-02-01

    temperature on an Instron load frame with a 222.41 kN (50 kip) load cell . The samples were compressed at the same strain rate as on the Gleeble...ID % RE Initial Density (cm 3 ) Density after Compression (cm 3 ) % Change in Density Test Temperature NT1 0 18.08 18.27 1.06 1000 NT3 0...4.1 Nano-Tungsten The results for the compression of the nano-tungsten samples are shown in tables 2 and 3 and figure 5. During testing, sample NT1

  16. Robotic system for process sampling

    International Nuclear Information System (INIS)

    Dyches, G.M.

    1985-01-01

    A three-axis cartesian geometry robot for process sampling was developed at the Savannah River Laboratory (SRL) and implemented in one of the site radioisotope separations facilities. Use of the robot reduces personnel radiation exposure and contamination potential by routinely handling sample containers under operator control in a low-level radiation area. This robot represents the initial phase of a longer term development program to use robotics for further sample automation. Preliminary design of a second generation robot with additional capabilities is also described. 8 figs

  17. Good outcome of adolescent onset anorexia nervosa after systematic treatment. Intermediate to long-term follow-up of a representative county-sample.

    Science.gov (United States)

    Halvorsen, Inger; Andersen, Anne; Heyerdahl, Sonja

    2004-10-01

    We studied the intermediate to long-term outcome of childhood and adolescent onset anorexia nervosa (AN), in a sample that had received systematic treatment based on close cooperation between parents, paediatric department and child and adolescent psychiatry. Of 55 female AN-patients, 51 were examined 3.5-14.5 years after treatment start. The material includes all AN-patients under 18 years in one county that received inpatient treatment and almost all that received outpatient treatment, during the time period 1986-1998. Forty-two (82%) subjects had no eating disorder (ED) at follow-up, one (2%) had AN, one (2%) bulimia nervosa (BN) and seven (14%) had less severe ED (EDNOS). Except the one with BN, none had bulimic symptoms. There was no mortality. Twenty (41%) had one or more other axis-1 psychiatric diagnoses at follow-up. Depression and anxiety disorders were most frequent. Psychosocial functioning assessed by Global Assessment of Functioning (GAF) was fairly good; mean 73+/-SD14 for symptoms and mean 77+/-SD13 for functioning. Only 48% were satisfied with life, compared to 83% in a normal population sample. Our conclusion is that the eating disorder outcome was good. However, in accordance with other studies, many subjects had other psychiatric problems at follow-up.

  18. Tests on standard concrete samples

    CERN Multimedia

    CERN PhotoLab

    1973-01-01

    Compression and tensile tests on standard concrete samples. The use of centrifugal force in tensile testing has been developed by the SB Division and the instruments were built in the Central workshops.

  19. Venus Suface Sampling and Analysis

    Data.gov (United States)

    National Aeronautics and Space Administration — This effort is developing the technology to transfer particulate samples from a Venus drill (being developed by Honeybee Robotics in a Phase 2 Small Business...

  20. Soil Gas Sampling Operating Procedure

    Science.gov (United States)

    EPA Region 4 Science and Ecosystem Support Division (SESD) document that describes general and specific procedures, methods, and considerations when collecting soil gas samples for field screening or laboratory analysis.

  1. Appendix F - Sample Contingency Plan

    Science.gov (United States)

    This sample Contingency Plan in Appendix F is intended to provide examples of contingency planning as a reference when a facility determines that the required secondary containment is impracticable, pursuant to 40 CFR §112.7(d).

  2. Hot sample archiving. Revision 3

    International Nuclear Information System (INIS)

    McVey, C.B.

    1995-01-01

    This Engineering Study revision evaluated the alternatives to provide tank waste characterization analytical samples for a time period as recommended by the Tank Waste Remediation Systems Program. The recommendation of storing 40 ml segment samples for a period of approximately 18 months (6 months past the approval date of the Tank Characterization Report) and then composite the core segment material in 125 ml containers for a period of five years. The study considers storage at 222-S facility. It was determined that the critical storage problem was in the hot cell area. The 40 ml sample container has enough material for approximately 3 times the required amount for a complete laboratory re-analysis. The final result is that 222-S can meet the sample archive storage requirements. During the 100% capture rate the capacity is exceeded in the hot cell area, but quick, inexpensive options are available to meet the requirements

  3. Sodium sampling and impurities determination

    International Nuclear Information System (INIS)

    Docekal, J.; Kovar, C.; Stuchlik, S.

    1980-01-01

    Samples may be obtained from tubes in-built in the sodium facility and further processed or they are taken into crucibles, stored and processed later. Another sampling method is a method involving vacuum distillation of sodium, thus concentrating impurities. Oxygen is determined by malgamation, distillation or vanadium balance methods. Hydrogen is determined by the metal diaphragm extraction, direct extraction or amalgamation methods. Carbon is determined using dry techniques involving burning a sodium sample at 1100 degC or using wet techniques by dissolving the sample with an acid. Trace amounts of metal impurities are determined after dissolving sodium in ethanol. The trace metals are concentrated and sodium excess is removed. (M.S.)

  4. Biological Sample Monitoring Database (BSMDBS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Biological Sample Monitoring Database System (BSMDBS) was developed for the Northeast Fisheries Regional Office and Science Center (NER/NEFSC) to record and...

  5. Apparatus for sampling hazardous media

    International Nuclear Information System (INIS)

    Gardner, J.F.; Showalter, T.W.

    1984-01-01

    An apparatus for sampling a hazardous medium, such as radioactive or chemical waste, selectively collects a predetermined quantity of the medium in a recess of an end-over-end rotatable valving member. This collected quantity is deposited in a receiving receptacle located in a cavity while the receiving receptacle is in a sealed relationship with a recess to prevent dusting of the sampled media outside the receiving receptacle. The receiving receptacle is removably fitted within a vehicle body which is, in turn, slidably movable upon a track within a transport tube. The receiving receptacle is transported in the vehicle body from its sample receiving position within a container for the hazardous medium to a sample retrieval position outside the medium container. The receiving receptacle may then be removed from the vehicle body, capped and taken to a laboratory for chemical analysis. (author)

  6. Sample size determination and power

    CERN Document Server

    Ryan, Thomas P, Jr

    2013-01-01

    THOMAS P. RYAN, PhD, teaches online advanced statistics courses for Northwestern University and The Institute for Statistics Education in sample size determination, design of experiments, engineering statistics, and regression analysis.

  7. Subsurface Noble Gas Sampling Manual

    Energy Technology Data Exchange (ETDEWEB)

    Carrigan, C. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sun, Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-18

    The intent of this document is to provide information about best available approaches for performing subsurface soil gas sampling during an On Site Inspection or OSI. This information is based on field sampling experiments, computer simulations and data from the NA-22 Noble Gas Signature Experiment Test Bed at the Nevada Nuclear Security Site (NNSS). The approaches should optimize the gas concentration from the subsurface cavity or chimney regime while simultaneously minimizing the potential for atmospheric radioxenon and near-surface Argon-37 contamination. Where possible, we quantitatively assess differences in sampling practices for the same sets of environmental conditions. We recognize that all sampling scenarios cannot be addressed. However, if this document helps to inform the intuition of the reader about addressing the challenges resulting from the inevitable deviations from the scenario assumed here, it will have achieved its goal.

  8. More practical critical height sampling.

    Science.gov (United States)

    Thomas B. Lynch; Jeffrey H. Gove

    2015-01-01

    Critical Height Sampling (CHS) (Kitamura 1964) can be used to predict cubic volumes per acre without using volume tables or equations. The critical height is defined as the height at which the tree stem appears to be in borderline condition using the point-sampling angle gauge (e.g. prism). An estimate of cubic volume per acre can be obtained from multiplication of the...

  9. Sampling criteria in multicollection searching.

    Science.gov (United States)

    Gilio, A.; Scozzafava, R.; Marchetti, P. G.

    In the first stage of the document retrieval process, no information concerning relevance of a particular document is available. On the other hand, computer implementation requires that the analysis be made only for a sample of retrieved documents. This paper addresses the significance and suitability of two different sampling criteria for a multicollection online search facility. The inevitability of resorting to a logarithmic criterion in order to achieve a "spread of representativeness" from the multicollection is demonstrated.

  10. Sample Reuse in Statistical Remodeling.

    Science.gov (United States)

    1987-08-01

    as the jackknife and bootstrap, is an expansion of the functional, T(Fn), or of its distribution function or both. Frangos and Schucany (1987a) used...accelerated bootstrap. In the same report Frangos and Schucany demonstrated the small sample superiority of that approach over the proposals that take...higher order terms of an Edgeworth expansion into account. In a second report Frangos and Schucany (1987b) examined the small sample performance of

  11. Possibilities for automating coal sampling

    Energy Technology Data Exchange (ETDEWEB)

    Helekal, J; Vankova, J

    1987-11-01

    Outlines sampling equipment in use (AVR-, AVP-, AVN- and AVK-series samplers and RDK- and RDH-series separators produced by the Coal Research Institute, Ostrava; extractors, crushers and separators produced by ORGREZ). The Ostrava equipment covers bituminous coal needs while ORGREZ provides equipment for energy coal requirements. This equipment is designed to handle coal up to 200 mm in size at a throughput of up to 1200 t/h. Automation of sampling equipment is foreseen.

  12. Environmental surveillance master sampling schedule

    Energy Technology Data Exchange (ETDEWEB)

    Bisping, L.E.

    1993-01-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). Samples are routinely collected and analyzed to determine the quality of air, surface water, ground water, soil, sediment, wildlife, vegetation, foodstuffs, and farm products at Hanford Site and surrounding communities. This document contains the planned schedule for routine sample collection for the Surface Environmental Surveillance Project (SESP) and Drinking Water Project, and Ground-Water Surveillance Project.

  13. Large Sample Neutron Activation Analysis of Heterogeneous Samples

    International Nuclear Information System (INIS)

    Stamatelatos, I.E.; Vasilopoulou, T.; Tzika, F.

    2018-01-01

    A Large Sample Neutron Activation Analysis (LSNAA) technique was developed for non-destructive analysis of heterogeneous bulk samples. The technique incorporated collimated scanning and combining experimental measurements and Monte Carlo simulations for the identification of inhomogeneities in large volume samples and the correction of their effect on the interpretation of gamma-spectrometry data. Corrections were applied for the effect of neutron self-shielding, gamma-ray attenuation, geometrical factor and heterogeneous activity distribution within the sample. A benchmark experiment was performed to investigate the effect of heterogeneity on the accuracy of LSNAA. Moreover, a ceramic vase was analyzed as a whole demonstrating the feasibility of the technique. The LSNAA results were compared against results obtained by INAA and a satisfactory agreement between the two methods was observed. This study showed that LSNAA is a technique capable to perform accurate non-destructive, multi-elemental compositional analysis of heterogeneous objects. It also revealed the great potential of the technique for the analysis of precious objects and artefacts that need to be preserved intact and cannot be damaged for sampling purposes. (author)

  14. Testing a groundwater sampling tool: Are the samples representative?

    International Nuclear Information System (INIS)

    Kaback, D.S.; Bergren, C.L.; Carlson, C.A.; Carlson, C.L.

    1989-01-01

    A ground water sampling tool, the HydroPunch trademark, was tested at the Department of Energy's Savannah River Site in South Carolina to determine if representative ground water samples could be obtained without installing monitoring wells. Chemical analyses of ground water samples collected with the HydroPunch trademark from various depths within a borehole were compared with chemical analyses of ground water from nearby monitoring wells. The site selected for the test was in the vicinity of a large coal storage pile and a coal pile runoff basin that was constructed to collect the runoff from the coal storage pile. Existing monitoring wells in the area indicate the presence of a ground water contaminant plume that: (1) contains elevated concentrations of trace metals; (2) has an extremely low pH; and (3) contains elevated concentrations of major cations and anions. Ground water samples collected with the HydroPunch trademark provide in excellent estimate of ground water quality at discrete depths. Groundwater chemical data collected from various depths using the HydroPunch trademark can be averaged to simulate what a screen zone in a monitoring well would sample. The averaged depth-discrete data compared favorably with the data obtained from the nearby monitoring wells

  15. XRF analysis of mineralised samples

    International Nuclear Information System (INIS)

    Ahmedali, T.

    2002-01-01

    Full text: Software now supplied by instrument manufacturers has made it practical and convenient for users to analyse unusual samples routinely. Semiquantitative scanning software can be used for rapid preliminary screening of elements ranging from Carbon to Uranium, prior to assigning mineralised samples to an appropriate quantitative analysis routine. The general quality and precision of analytical results obtained from modern XRF spectrometers can be significantly enhanced by several means: a. Modifications in preliminary sample preparation can result in less contamination from crushing and grinding equipment. Optimised techniques of actual sample preparation can significantly increase precision of results. b. Employment of automatic data recording balances and the use of catch weights during sample preparation reduces technician time as well as weighing errors. * c. Consistency of results can be improved significantly by the use of appropriate stable drift monitors with a statistically significant content of the analyte d. A judicious selection of kV/mA combinations, analysing crystals, primary beam filters, collimators, peak positions, accurate background correction and peak overlap corrections, followed by the use of appropriate matrix correction procedures. e. Preventative maintenance procedures for XRF spectrometers and ancillary equipment, which can also contribute significantly to reducing instrument down times, are described. Examples of various facets of sample processing routines are given from the XRF spectrometer component of a multi-instrument analytical university facility, which provides XRF data to 17 Canadian universities. Copyright (2002) Australian X-ray Analytical Association Inc

  16. Inorganic elements in sugar samples

    Energy Technology Data Exchange (ETDEWEB)

    Salles, Paulo M.B. de; Campos, Tarcisio P.R. de, E-mail: pauladesalles@yahoo.com.br, E-mail: tprcampos@pq.cnpq.br [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Menezes, Maria Angela de B.C., E-mail: menezes@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    Sugar is considered a safe food ingredient; however, it can be contaminated by organic elements since its planting until its production process. Thus, this study aims at checking the presence of inorganic elements in samples of crystal, refined and brown sugar available for consumption in Brazil. The applied technique was neutron activation analysis, the k{sub 0} method, using the TRIGA MARK - IPR-R1 reactor located at CDTN/CNEN, in Belo Horizonte. It was identified the presence of elements such as, Au, Br, Co, Cr, Hf, K, Na, Sb, Sc and Zn in the samples of crystal/refined sugar and the presence of As, Au, Br, Ca, Co, Cr, Cs, Fe, Hf, K, Na, Sb, Sc, Sm, Sr, Th and Zn in the brown sugar samples. The applied technique was appropriate to this study because it was not necessary to put the samples in solution, essential condition in order to apply other techniques, avoiding contaminations and sample losses, besides allowing a multi elementary detection in different sugar samples. (author)

  17. Inorganic elements in sugar samples

    International Nuclear Information System (INIS)

    Salles, Paulo M.B. de; Campos, Tarcisio P.R. de

    2013-01-01

    Sugar is considered a safe food ingredient; however, it can be contaminated by organic elements since its planting until its production process. Thus, this study aims at checking the presence of inorganic elements in samples of crystal, refined and brown sugar available for consumption in Brazil. The applied technique was neutron activation analysis, the k 0 method, using the TRIGA MARK - IPR-R1 reactor located at CDTN/CNEN, in Belo Horizonte. It was identified the presence of elements such as, Au, Br, Co, Cr, Hf, K, Na, Sb, Sc and Zn in the samples of crystal/refined sugar and the presence of As, Au, Br, Ca, Co, Cr, Cs, Fe, Hf, K, Na, Sb, Sc, Sm, Sr, Th and Zn in the brown sugar samples. The applied technique was appropriate to this study because it was not necessary to put the samples in solution, essential condition in order to apply other techniques, avoiding contaminations and sample losses, besides allowing a multi elementary detection in different sugar samples. (author)

  18. Improved sample size determination for attributes and variables sampling

    International Nuclear Information System (INIS)

    Stirpe, D.; Picard, R.R.

    1985-01-01

    Earlier INMM papers have addressed the attributes/variables problem and, under conservative/limiting approximations, have reported analytical solutions for the attributes and variables sample sizes. Through computer simulation of this problem, we have calculated attributes and variables sample sizes as a function of falsification, measurement uncertainties, and required detection probability without using approximations. Using realistic assumptions for uncertainty parameters of measurement, the simulation results support the conclusions: (1) previously used conservative approximations can be expensive because they lead to larger sample sizes than needed; and (2) the optimal verification strategy, as well as the falsification strategy, are highly dependent on the underlying uncertainty parameters of the measurement instruments. 1 ref., 3 figs

  19. Are most samples of animals systematically biased? Consistent individual trait differences bias samples despite random sampling.

    Science.gov (United States)

    Biro, Peter A

    2013-02-01

    Sampling animals from the wild for study is something nearly every biologist has done, but despite our best efforts to obtain random samples of animals, 'hidden' trait biases may still exist. For example, consistent behavioral traits can affect trappability/catchability, independent of obvious factors such as size and gender, and these traits are often correlated with other repeatable physiological and/or life history traits. If so, systematic sampling bias may exist for any of these traits. The extent to which this is a problem, of course, depends on the magnitude of bias, which is presently unknown because the underlying trait distributions in populations are usually unknown, or unknowable. Indeed, our present knowledge about sampling bias comes from samples (not complete population censuses), which can possess bias to begin with. I had the unique opportunity to create naturalized populations of fish by seeding each of four small fishless lakes with equal densities of slow-, intermediate-, and fast-growing fish. Using sampling methods that are not size-selective, I observed that fast-growing fish were up to two-times more likely to be sampled than slower-growing fish. This indicates substantial and systematic bias with respect to an important life history trait (growth rate). If correlations between behavioral, physiological and life-history traits are as widespread as the literature suggests, then many animal samples may be systematically biased with respect to these traits (e.g., when collecting animals for laboratory use), and affect our inferences about population structure and abundance. I conclude with a discussion on ways to minimize sampling bias for particular physiological/behavioral/life-history types within animal populations.

  20. Material sampling for rotor evaluation

    International Nuclear Information System (INIS)

    Mercaldi, D.; Parker, J.

    1990-01-01

    Decisions regarding continued operation of aging rotating machinery must often be made without adequate knowledge of rotor material conditions. Physical specimens of the material are not generally available due to lack of an appropriate sampling technique or the high cost and inconvenience of obtaining such samples. This is despite the fact that examination of such samples may be critical to effectively assess the degradation of mechanical properties of the components in service or to permit detailed examination of microstructure and surface flaws. Such information permits a reduction in the uncertainty of remaining life estimates for turbine rotors to avoid unnecessarily premature and costly rotor retirement decisions. This paper describes the operation and use of a recently developed material sampling device which machines and recovers an undeformed specimen from the surface of rotor bores or other components for metallurgical analysis. The removal of the thin, wafer-like sample has a negligible effect on the structural integrity of these components, due to the geometry and smooth surface finish of the resulting shallow depression. Samples measuring approximately 0.03 to 0.1 inches (0.76 to 2.5 mm) thick by 0.5 to 1.0 inch (1.3 to 2.5 cm) in diameter can be removed without mechanical deformation or thermal degradation of the sample or the remaining component material. The device is operated remotely from a control console and can be used externally or internally on any surface for which there is at least a three inch (7.6 cm) working clearance. Application of the device in two case studies of turbine-generator evaluations are presented

  1. Adaptive sampling of AEM transients

    Science.gov (United States)

    Di Massa, Domenico; Florio, Giovanni; Viezzoli, Andrea

    2016-02-01

    This paper focuses on the sampling of the electromagnetic transient as acquired by airborne time-domain electromagnetic (TDEM) systems. Typically, the sampling of the electromagnetic transient is done using a fixed number of gates whose width grows logarithmically (log-gating). The log-gating has two main benefits: improving the signal to noise (S/N) ratio at late times, when the electromagnetic signal has amplitudes equal or lower than the natural background noise, and ensuring a good resolution at the early times. However, as a result of fixed time gates, the conventional log-gating does not consider any geological variations in the surveyed area, nor the possibly varying characteristics of the measured signal. We show, using synthetic models, how a different, flexible sampling scheme can increase the resolution of resistivity models. We propose a new sampling method, which adapts the gating on the base of the slope variations in the electromagnetic (EM) transient. The use of such an alternative sampling scheme aims to get more accurate inverse models by extracting the geoelectrical information from the measured data in an optimal way.

  2. SWOT ANALYSIS ON SAMPLING METHOD

    Directory of Open Access Journals (Sweden)

    CHIS ANCA OANA

    2014-07-01

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

  3. Continuous sampling from distributed streams

    DEFF Research Database (Denmark)

    Graham, Cormode; Muthukrishnan, S.; Yi, Ke

    2012-01-01

    A fundamental problem in data management is to draw and maintain a sample of a large data set, for approximate query answering, selectivity estimation, and query planning. With large, streaming data sets, this problem becomes particularly difficult when the data is shared across multiple distribu......A fundamental problem in data management is to draw and maintain a sample of a large data set, for approximate query answering, selectivity estimation, and query planning. With large, streaming data sets, this problem becomes particularly difficult when the data is shared across multiple...... distributed sites. The main challenge is to ensure that a sample is drawn uniformly across the union of the data while minimizing the communication needed to run the protocol on the evolving data. At the same time, it is also necessary to make the protocol lightweight, by keeping the space and time costs low...... for each participant. In this article, we present communication-efficient protocols for continuously maintaining a sample (both with and without replacement) from k distributed streams. These apply to the case when we want a sample from the full streams, and to the sliding window cases of only the W most...

  4. Distance sampling methods and applications

    CERN Document Server

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

    2015-01-01

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

  5. Ball assisted device for analytical surface sampling

    Science.gov (United States)

    ElNaggar, Mariam S; Van Berkel, Gary J; Covey, Thomas R

    2015-11-03

    A system for sampling a surface includes a sampling probe having a housing and a socket, and a rolling sampling sphere within the socket. The housing has a sampling fluid supply conduit and a sampling fluid exhaust conduit. The sampling fluid supply conduit supplies sampling fluid to the sampling sphere. The sampling fluid exhaust conduit has an inlet opening for receiving sampling fluid carried from the surface by the sampling sphere. A surface sampling probe and a method for sampling a surface are also disclosed.

  6. Sample preparation in alkaline media

    International Nuclear Information System (INIS)

    Nobrega, Joaquim A.; Santos, Mirian C.; Sousa, Rafael A. de; Cadore, Solange; Barnes, Ramon M.; Tatro, Mark

    2006-01-01

    The use of tetramethylammonium hydroxide, tertiary amines and strongly alkaline reagents for sample treatment involving extraction and digestion procedures is discussed in this review. The preparation of slurries is also discussed. Based on literature data, alkaline media offer a good alternative for sample preparation involving an appreciable group of analytes in different types of samples. These reagents are also successfully employed in tailored speciation procedures wherein there is a critical dependence on maintenance of chemical forms. The effects of these reagents on measurements performed using spectroanalytical techniques are discussed. Several undesirable effects on transport and atomization processes necessitate use of the method of standard additions to obtain accurate results. It is also evident that alkaline media can improve the performance of techniques such as inductively coupled plasma mass spectrometry and accessories, such as autosamplers coupled to graphite furnace atomic absorption spectrometers

  7. β-NMR sample optimization

    CERN Document Server

    Zakoucka, Eva

    2013-01-01

    During my summer student programme I was working on sample optimization for a new β-NMR project at the ISOLDE facility. The β-NMR technique is well-established in solid-state physics and just recently it is being introduced for applications in biochemistry and life sciences. The β-NMR collaboration will be applying for beam time to the INTC committee in September for three nuclei: Cu, Zn and Mg. Sample optimization for Mg was already performed last year during the summer student programme. Therefore sample optimization for Cu and Zn had to be completed as well for the project proposal. My part in the project was to perform thorough literature research on techniques studying Cu and Zn complexes in native conditions, search for relevant binding candidates for Cu and Zn applicable for ß-NMR and eventually evaluate selected binding candidates using UV-VIS spectrometry.

  8. Sampling methodology and PCB analysis

    International Nuclear Information System (INIS)

    Dominelli, N.

    1995-01-01

    As a class of compounds PCBs are extremely stable and resist chemical and biological decomposition. Diluted solutions exposed to a range of environmental conditions will undergo some preferential degradation and the resulting mixture may differ considerably from the original PCB used as insulating fluid in electrical equipment. The structure of mixtures of PCBs (synthetic compounds prepared by direct chlorination of biphenyl with chlorine gas) is extremely complex and presents a formidable analytical problem, further complicated by the presence of PCBs as contaminants in oils to soils to water. This paper provides some guidance into sampling and analytical procedures; it also points out various potential problems encountered during these processes. The guidelines provided deal with sample collection, storage and handling, sample stability, laboratory analysis (usually gas chromatography), determination of PCB concentration, calculation of total PCB content, and quality assurance. 1 fig

  9. Environmental surveillance master sampling schedule

    International Nuclear Information System (INIS)

    Bisping, L.E.

    1997-01-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest National Laboratory (PNNL)(a) for the US Department of Energy (DOE). This document contains the planned 1997 schedules for routine collection of samples for the Surface Environmental Surveillance Project (SESP) and Drinking Water Monitoring Project. In addition, Section 3.0, Biota, also reflects a rotating collection schedule identifying the year a specific sample is scheduled for collection. The purpose of these monitoring projects is to evaluate levels of radioactive and nonradioactive pollutants in the Hanford environs, as required in DOE Order 5400.1, General Environmental Protection Program, and DOE Order 5400.5, Radiation Protection of the Public and the Environment. The sampling methods will be the same as those described in the Environmental Monitoring Plan, US Department of Energy, Richland Operations Office, DOE/RL91-50, Rev. 1, US Department of Energy, Richland, Washington

  10. Soil sampling for environmental contaminants

    International Nuclear Information System (INIS)

    2004-10-01

    The Consultants Meeting on Sampling Strategies, Sampling and Storage of Soil for Environmental Monitoring of Contaminants was organized by the International Atomic Energy Agency to evaluate methods for soil sampling in radionuclide monitoring and heavy metal surveys for identification of punctual contamination (hot particles) in large area surveys and screening experiments. A group of experts was invited by the IAEA to discuss and recommend methods for representative soil sampling for different kinds of environmental issues. The ultimate sinks for all kinds of contaminants dispersed within the natural environment through human activities are sediment and soil. Soil is a particularly difficult matrix for environmental pollution studies as it is generally composed of a multitude of geological and biological materials resulting from weathering and degradation, including particles of different sizes with varying surface and chemical properties. There are so many different soil types categorized according to their content of biological matter, from sandy soils to loam and peat soils, which make analytical characterization even more complicated. Soil sampling for environmental monitoring of pollutants, therefore, is still a matter of debate in the community of soil, environmental and analytical sciences. The scope of the consultants meeting included evaluating existing techniques with regard to their practicability, reliability and applicability to different purposes, developing strategies of representative soil sampling for cases not yet considered by current techniques and recommending validated techniques applicable to laboratories in developing Member States. This TECDOC includes a critical survey of existing approaches and their feasibility to be applied in developing countries. The report is valuable for radioanalytical laboratories in Member States. It would assist them in quality control and accreditation process

  11. Sample processing device and method

    DEFF Research Database (Denmark)

    2011-01-01

    A sample processing device is disclosed, which sample processing device comprises a first substrate and a second substrate, where the first substrate has a first surface comprising two area types, a first area type with a first contact angle with water and a second area type with a second contact...... angle with water, the first contact angle being smaller than the second contact angle. The first substrate defines an inlet system and a preparation system in areas of the first type which two areas are separated by a barrier system in an area of the second type. The inlet system is adapted to receive...

  12. The MEGAPIE PIE sample preparation

    International Nuclear Information System (INIS)

    Wohlmuther, M.; Boutellier, V.; Dai, Y.; Gavillet, D.; Geissmann, K.; Hahl, S.; Hammer, B.; Lagotzki, A.; Leu, H.; Linder, H.P.; Kalt, A.; Kuster, D.; Neuhausen, J.; Schumann, D.; Schwarz, R.; Schweikert, H.; Spahr, A.; Suter, P.; Teichmann, S.; Thomsen, K.; Wiese, H.; Wagner, W.; Zimmermann, U.; Zumbach, C.

    2015-01-01

    On the way towards Accelerator-driven Systems (ADS), the MEGAPIE (Mega-Watt Pilot Experiment) project is one of the key milestones. The MEGAPIE project aimed to prove that a liquid Lead-Bismuth-Eutectic (LBE) spallation target can be licensed, planned, built, operated, dismantled, examined and disposed. The project has finished the phase of producing the samples for Post-irradiation Examination (PIE). Samples to study structural material property changes due to the harsh environment of high temperatures, contact with flowing liquid metal (LBE), proton and neutron irradiation will be investigated by all partner laboratories (CEA, CNRS, ENEA, KIT, PSI and SCK-CEN). (authors)

  13. Spent nuclear fuel sampling strategy

    International Nuclear Information System (INIS)

    Bergmann, D.W.

    1995-01-01

    This report proposes a strategy for sampling the spent nuclear fuel (SNF) stored in the 105-K Basins (105-K East and 105-K West). This strategy will support decisions concerning the path forward SNF disposition efforts in the following areas: (1) SNF isolation activities such as repackaging/overpacking to a newly constructed staging facility; (2) conditioning processes for fuel stabilization; and (3) interim storage options. This strategy was developed without following the Data Quality Objective (DQO) methodology. It is, however, intended to augment the SNF project DQOS. The SNF sampling is derived by evaluating the current storage condition of the SNF and the factors that effected SNF corrosion/degradation

  14. Sampling for stereology in lungs

    Directory of Open Access Journals (Sweden)

    J. R. Nyengaard

    2006-12-01

    Full Text Available The present article reviews the relevant stereological estimators for obtaining reliable quantitative structural data from the lungs. Stereological sampling achieves reliable, quantitative information either about the whole lung or complete lobes, whilst minimising the workload. Studies have used systematic random sampling, which has fixed and constant sampling probabilities on all blocks, sections and fields of view. For an estimation of total lung or lobe volume, the Cavalieri principle can be used, but it is not useful in estimating individual cell volume due to various effects from over- or underprojection. If the number of certain structures is required, two methods can be used: the disector and the fractionator. The disector method is a three-dimensional stereological probe for sampling objects according to their number. However, it may be affected on tissue deformation and, therefore, the fractionator method is often the preferred sampling principle. In this method, a known and predetermined fraction of an object is sampled in one or more steps, with the final step estimating the number. Both methods can be performed in a physical and optical manner, therefore enabling cells and larger lung structure numbers (e.g. number of alveoli to be estimated. Some estimators also require randomisation of orientation, so that all directions have an equal chance of being chosen. Using such isotropic sections, surface area, length, and diameter can be estimated on a Cavalieri set of sections. Stereology can also illustrate the potential for transport between two compartments by analysing the barrier width. Estimating the individual volume of cells can be achieved by local stereology using a two-step procedure that first samples lung cells using the disector and then introduces individual volume estimation of the sampled cells. The coefficient of error of most unbiased stereological estimators is a combination of variance from blocks, sections, fields

  15. GET electronics samples data analysis

    International Nuclear Information System (INIS)

    Giovinazzo, J.; Goigoux, T.; Anvar, S.; Baron, P.; Blank, B.; Delagnes, E.; Grinyer, G.F.; Pancin, J.; Pedroza, J.L.; Pibernat, J.; Pollacco, E.; Rebii, A.

    2016-01-01

    The General Electronics for TPCs (GET) has been developed to equip a generation of time projection chamber detectors for nuclear physics, and may also be used for a wider range of detector types. The goal of this paper is to propose first analysis procedures to be applied on raw data samples from the GET system, in order to correct for systematic effects observed on test measurements. We also present a method to estimate the response function of the GET system channels. The response function is required in analysis where the input signal needs to be reconstructed, in terms of time distribution, from the registered output samples.

  16. Quartz analysis in gravimetric sampling

    International Nuclear Information System (INIS)

    Rex, D.A.

    1990-01-01

    An overview of the methods employed in the assessment of quartz exposure is provided. The principles and some of the problems associated with each method is discussed. The methods reviewed include wet chemical methods, X-ray diffraction and infrared absorption of which the latter two methods are deemed appropriate for analysing quartz on personal gravimetric collected samples. The implications of combining area samples collected over a six month period, and performing only a single quartz analysis rather than separate analyses, are considered. Finally, various options open to mines with regard to their involvement with quartz analysis are also briefly discussed. 35 refs., 6 figs., 1 tab

  17. Representative process sampling - in practice

    DEFF Research Database (Denmark)

    Esbensen, Kim; Friis-Pedersen, Hans Henrik; Julius, Lars Petersen

    2007-01-01

    Didactic data sets representing a range of real-world processes are used to illustrate "how to do" representative process sampling and process characterisation. The selected process data lead to diverse variogram expressions with different systematics (no range vs. important ranges; trends and....../or periodicity; different nugget effects and process variations ranging from less than one lag to full variogram lag). Variogram data analysis leads to a fundamental decomposition into 0-D sampling vs. 1-D process variances, based on the three principal variogram parameters: range, sill and nugget effect...

  18. The ocean sampling day consortium

    DEFF Research Database (Denmark)

    Kopf, Anna; Bicak, Mesude; Kottmann, Renzo

    2015-01-01

    Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate...... the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our...

  19. The potential impact of recruitment method on sample characteristics and treatment outcomes in a psychosocial trial for women with co-occurring substance use disorder and PTSD.

    Science.gov (United States)

    Winhusen, Theresa; Winstanley, Erin L; Somoza, Eugene; Brigham, Gregory

    2012-01-01

    Recruitment method can impact the sample composition of a clinical trial and, thus, the generalizability of the results, but the importance of recruitment method in substance use disorder trials has received little attention. The present paper sought to address this research gap by evaluating the association between recruitment method and sample characteristics and treatment outcomes in a substance use disorder trial. In a multi-site trial evaluating Seeking Safety (SS), relative to Women's Health Education (WHE), for women with co-occurring PTSD (either sub-threshold or full PTSD) and substance use disorders, one site assessed the method by which each participant was recruited. Data from this site (n=106), which recruited participants from newspaper advertising and clinic intakes, were analyzed. Participants recruited through advertising, relative to those from the clinic, had significantly higher levels of baseline drug use and higher rates of meeting DSM-IV-TR criteria for full PTSD. Results suggest that the effectiveness of SS in decreasing PTSD symptoms was greater for participants recruited through advertising relative to those recruited from the clinic. Conversely, the results revealed a significant treatment effect in the clinic-recruited participants, not seen in the advertising-recruited participants, with SS, relative to WHE, participants being more likely to report past week drug use during the follow-up phase. Recruitment method may impact sample composition and treatment effects. Replication of this finding would have important implications for substance use disorder efficacy trials which often utilize advertising to recruit participants. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  20. A randomized trial of a DWI intervention program for first offenders: intervention outcomes and interactions with antisocial personality disorder among a primarily American-Indian sample.

    Science.gov (United States)

    Woodall, W Gill; Delaney, Harold D; Kunitz, Stephen J; Westerberg, Verner S; Zhao, Hongwei

    2007-06-01

    Randomized trial evidence on the effectiveness of incarceration and treatment of first-time driving while intoxicated (DWI) offenders who are primarily American Indian has yet to be reported in the literature on DWI prevention. Further, research has confirmed the association of antisocial personality disorder (ASPD) with problems with alcohol including DWI. A randomized clinical trial was conducted, in conjunction with 28 days of incarceration, of a treatment program incorporating motivational interviewing principles for first-time DWI offenders. The sample of 305 offenders including 52 diagnosed as ASPD by the Diagnostic Interview Schedule were assessed before assignment to conditions and at 6, 12, and 24 months after discharge. Self-reported frequency of drinking and driving as well as various measures of drinking over the preceding 90 days were available at all assessments for 244 participants. Further, DWI rearrest data for 274 participants were available for analysis. Participants randomized to receive the first offender incarceration and treatment program reported greater reductions in alcohol consumption from baseline levels when compared with participants who were only incarcerated. Antisocial personality disorder participants reported heavier and more frequent drinking but showed significantly greater declines in drinking from intake to posttreatment assessments. Further, the treatment resulted in larger effects relative to the control on ASPD than non-ASPD participants. Nonconfrontational treatment may significantly enhance outcomes for DWI offenders with ASPD when delivered in an incarcerated setting, and in the present study, such effects were found in a primarily American-Indian sample.

  1. Conversion of National Health Insurance Service-National Sample Cohort (NHIS-NSC) Database into Observational Medical Outcomes Partnership-Common Data Model (OMOP-CDM).

    Science.gov (United States)

    You, Seng Chan; Lee, Seongwon; Cho, Soo-Yeon; Park, Hojun; Jung, Sungjae; Cho, Jaehyeong; Yoon, Dukyong; Park, Rae Woong

    2017-01-01

    It is increasingly necessary to generate medical evidence applicable to Asian people compared to those in Western countries. Observational Health Data Sciences a Informatics (OHDSI) is an international collaborative which aims to facilitate generating high-quality evidence via creating and applying open-source data analytic solutions to a large network of health databases across countries. We aimed to incorporate Korean nationwide cohort data into the OHDSI network by converting the national sample cohort into Observational Medical Outcomes Partnership-Common Data Model (OMOP-CDM). The data of 1.13 million subjects was converted to OMOP-CDM, resulting in average 99.1% conversion rate. The ACHILLES, open-source OMOP-CDM-based data profiling tool, was conducted on the converted database to visualize data-driven characterization and access the quality of data. The OMOP-CDM version of National Health Insurance Service-National Sample Cohort (NHIS-NSC) can be a valuable tool for multiple aspects of medical research by incorporation into the OHDSI research network.

  2. A gigahertz sampling transient analyzer

    International Nuclear Information System (INIS)

    Andrieu, F.; Balanca, C.; Bernet, J.M.; Lejeune, G.

    1975-01-01

    The AN 800 equipment was designed for the purpose of digital conversion of fast signals. The recording device had to be located close to the sensor. The equipment had to be highly reliable and had to transmit its output signals before and electromagnetic pulse disturbance. The sampling approach, with its readiness to digitalization, was selected as more convenient

  3. Treatability study sample exemption: update

    International Nuclear Information System (INIS)

    1997-01-01

    This document is a RCRA Information Brief intended to update the information in the 1991 Small-Scale Treatability Study Information Brief, and to address questions about the waste and treatability study sample exemptions that have arisen since References 3 and 5 were published

  4. Synchrotron/crystal sample preparation

    Science.gov (United States)

    Johnson, R. Barry

    1993-01-01

    The Center for Applied Optics (CAO) of the University of Alabama in Huntsville (UAH) prepared this final report entitled 'Synchrotron/Crystal Sample Preparation' in completion of contract NAS8-38609, Delivery Order No. 53. Hughes Danbury Optical Systems (HDOS) is manufacturing the Advanced X-ray Astrophysics Facility (AXAF) mirrors. These thin-walled, grazing incidence, Wolter Type-1 mirrors, varying in diameter from 1.2 to 0.68 meters, must be ground and polished using state-of-the-art techniques in order to prevent undue stress due to damage or the presence of crystals and inclusions. The effect of crystals on the polishing and grinding process must also be understood. This involves coating special samples of Zerodur and measuring the reflectivity of the coatings in a synchrotron system. In order to gain the understanding needed on the effect of the Zerodur crystals by the grinding and polishing process, UAH prepared glass samples by cutting, grinding, etching, and polishing as required to meet specifications for witness bars for synchrotron measurements and for investigations of crystals embedded in Zerodur. UAH then characterized these samples for subsurface damage and surface roughness and figure.

  5. Environmental surveillance master sampling schedule

    International Nuclear Information System (INIS)

    Bisping, L.E.

    1994-02-01

    This document contains the planned 1994 schedules for routine collection of samples for the Surface Environmental Surveillance Project (SESP), Drinking Water Project, and Ground-Water Surveillance Project. Samples are routinely collected for the SESP and analyzed to determine the quality of air, surface water, soil, sediment, wildlife, vegetation, foodstuffs, and farm products at Hanford Site and surrounding communities. The responsibility for monitoring the onsite drinking water falls outside the scope of the SESP. The Hanford Environmental Health Foundation is responsible for monitoring the nonradiological parameters as defined in the National Drinking Water Standards while PNL conducts the radiological monitoring of the onsite drinking water. PNL conducts the drinking water monitoring project concurrent with the SESP to promote efficiency and consistency, utilize the expertise developed over the years, and reduce costs associated with management, procedure development, data management, quality control and reporting. The ground-water sampling schedule identifies ground-water sampling events used by PNL for environmental surveillance of the Hanford Site

  6. The Lyman alpha reference sample

    DEFF Research Database (Denmark)

    Hayes, M.; Östlin, G.; Schaerer, D.

    2013-01-01

    We report on new imaging observations of the Lyman alpha emission line (Lyα), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample. We present images of 14 starburst galaxies at redshifts 0.028

  7. Sampling Assumptions in Inductive Generalization

    Science.gov (United States)

    Navarro, Daniel J.; Dry, Matthew J.; Lee, Michael D.

    2012-01-01

    Inductive generalization, where people go beyond the data provided, is a basic cognitive capability, and it underpins theoretical accounts of learning, categorization, and decision making. To complete the inductive leap needed for generalization, people must make a key "sampling" assumption about how the available data were generated.…

  8. Waste tank characterization sampling limits

    International Nuclear Information System (INIS)

    Tusler, L.A.

    1994-01-01

    This document is a result of the Plant Implementation Team Investigation into delayed reporting of the exotherm in Tank 241-T-111 waste samples. The corrective actions identified are to have immediate notification of appropriate Tank Farm Operations Shift Management if analyses with potential safety impact exceed established levels. A procedure, WHC-IP-0842 Section 12.18, ''TWRS Approved Sampling and Data Analysis by Designated Laboratories'' (WHC 1994), has been established to require all tank waste sampling (including core, auger and supernate) and tank vapor samples be performed using this document. This document establishes levels for specified analysis that require notification of the appropriate shift manager. The following categories provide numerical values for analysis that may indicate that a tank is either outside the operating specification or should be evaluated for inclusion on a Watch List. The information given is intended to translate an operating limit such as heat load, expressed in Btu/hour, to an analysis related limit, in this case cesium-137 and strontium-90 concentrations. By using the values provided as safety flags, the analytical laboratory personnel can notify a shift manager that a tank is in potential violation of an operating limit or that a tank should be considered for inclusion on a Watch List. The shift manager can then take appropriate interim measures until a final determination is made by engineering personnel

  9. Microholographic imaging of biological samples

    International Nuclear Information System (INIS)

    Haddad, W.S.; Cullen, D.; Solem, J.C.; Longworth, J.W.; McPherson, A.; Boyer, K.; Rhodes, C.K.

    1990-01-01

    A camera system suitable for x-ray microholography has been constructed. Visible light Fourier transform microholograms of biological samples and other test targets have been recorded and reconstructed digitally using a glycerol microdrop as a reference wave source. Current results give a resolution of ∼4 - 10 λ with λ = 514.5 nm. 11 refs., 1 fig

  10. Curiosity analyzes Martian soil samples

    Science.gov (United States)

    Showstack, Randy; Balcerak, Ernie

    2012-12-01

    NASA's Mars Curiosity rover has conducted its first analysis of Martian soil samples using multiple instruments, the agency announced at a 3 December news briefing at the AGU Fall Meeting in San Francisco. "These results are an unprecedented look at the chemical diversity in the area," said NASA's Michael Meyer, program scientist for Curiosity.

  11. Bayesian Sampling using Condition Indicators

    DEFF Research Database (Denmark)

    Faber, Michael H.; Sørensen, John Dalsgaard

    2002-01-01

    of condition indicators introduced by Benjamin and Cornell (1970) a Bayesian approach to quality control is formulated. The formulation is then extended to the case where the quality control is based on sampling of indirect information about the condition of the components, i.e. condition indicators...

  12. Mahalanobis' Contributions to Sample Surveys

    Indian Academy of Sciences (India)

    Sample Survey started its operations in October 1950 under the ... and adopted random cuts for estimating the acreage under jute ... demographic factors relating to indebtedness, unemployment, ... traffic surveys, demand for currency coins and average life of .... Mahalanobis derived the optimum allocation in stratified.

  13. Environmental surveillance master sampling schedule

    Energy Technology Data Exchange (ETDEWEB)

    Bisping, L.E.

    1994-02-01

    This document contains the planned 1994 schedules for routine collection of samples for the Surface Environmental Surveillance Project (SESP), Drinking Water Project, and Ground-Water Surveillance Project. Samples are routinely collected for the SESP and analyzed to determine the quality of air, surface water, soil, sediment, wildlife, vegetation, foodstuffs, and farm products at Hanford Site and surrounding communities. The responsibility for monitoring the onsite drinking water falls outside the scope of the SESP. The Hanford Environmental Health Foundation is responsible for monitoring the nonradiological parameters as defined in the National Drinking Water Standards while PNL conducts the radiological monitoring of the onsite drinking water. PNL conducts the drinking water monitoring project concurrent with the SESP to promote efficiency and consistency, utilize the expertise developed over the years, and reduce costs associated with management, procedure development, data management, quality control and reporting. The ground-water sampling schedule identifies ground-water sampling events used by PNL for environmental surveillance of the Hanford Site.

  14. The RECONS 10 Parsec Sample

    Science.gov (United States)

    Henry, Todd; Dieterich, Sergio; Finch, C.; Ianna, P. A.; Jao, W.-C.; Riedel, Adric; Subasavage, John; Winters, J.; RECONS Team

    2018-01-01

    The sample of stars, brown dwarfs, and exoplanets known within 10 parsecs of our Solar System as of January 1, 2017 is presented. The current census is comprised of 416 objects made up of 371 stars (including the Sun and white dwarfs) and 45 brown dwarfs. The stars are known to be orbited by 43 planets (eight in our Solar System and 35 exoplanets). There are 309 systems within 10 pc, including 275 with stellar primaries and 34 systems containing only brown dwarfs.Via a long-term astrometric effort at CTIO, the RECONS (REsearch Consortium On Nearby Stars, www.recons.org) team has added 44 stellar systems to the sample, accounting for one of every seven systems known within 10 pc. Overall, the 278 red dwarfs clearly dominate the sample, accounting for 75% of all stars known within 10 pc. The completeness of the sample is assessed, indicating that a few red, brown, and white dwarfs within 10 pc may be discovered, both as primaries and secondaries, although we estimate that 90% of the stellar systems have been identified. The evolution of the 10 pc sample over the past century is outlined to illustrate our growing knowledge of the solar neighborhood.The luminosity and mass functions for stars within 10 pc are described. In contrast to many studies, once all known close multiples are resolved into individual components, the true mass function rises to the end of the stellar main sequence, followed by a precipitous drop in the number of brown dwarfs, which are outnumbered 8.2 to 1 by stars. Of the 275 stellar primaries in the sample, 182 (66%) are single, 75 (27%) have at least one stellar companion, only 8 (3%) have a brown dwarf companion, and 19 (7%) systems are known to harbor planets. Searches for brown dwarf companions to stars in this sample have been quite rigorous, so the brown dwarf companion rate is unlikely to rise significantly. In contrast, searches for exoplanets, particularly terrestrial planets, have been limited. Thus, overall the solar neighborhood is

  15. Sample Size and Statistical Conclusions from Tests of Fit to the Rasch Model According to the Rasch Unidimensional Measurement Model (Rumm) Program in Health Outcome Measurement.

    Science.gov (United States)

    Hagell, Peter; Westergren, Albert

    Sample size is a major factor in statistical null hypothesis testing, which is the basis for many approaches to testing Rasch model fit. Few sample size recommendations for testing fit to the Rasch model concern the Rasch Unidimensional Measurement Models (RUMM) software, which features chi-square and ANOVA/F-ratio based fit statistics, including Bonferroni and algebraic sample size adjustments. This paper explores the occurrence of Type I errors with RUMM fit statistics, and the effects of algebraic sample size adjustments. Data with simulated Rasch model fitting 25-item dichotomous scales and sample sizes ranging from N = 50 to N = 2500 were analysed with and without algebraically adjusted sample sizes. Results suggest the occurrence of Type I errors with N less then or equal to 500, and that Bonferroni correction as well as downward algebraic sample size adjustment are useful to avoid such errors, whereas upward adjustment of smaller samples falsely signal misfit. Our observations suggest that sample sizes around N = 250 to N = 500 may provide a good balance for the statistical interpretation of the RUMM fit statistics studied here with respect to Type I errors and under the assumption of Rasch model fit within the examined frame of reference (i.e., about 25 item parameters well targeted to the sample).

  16. Sampling knowledge: the hermeneutics of snowball sampling in qualitative research

    OpenAIRE

    Noy, Chaim

    2008-01-01

    During the past two decades we have witnessed a rather impressive growth of theoretical innovations and conceptual revisions of epistemological and methodological approaches within constructivist-qualitative quarters of the social sciences. Methodological discussions have commonly addressed a variety of methods for collecting and analyzing empirical material, yet the critical grounds upon which these were reformulated have rarely been extended to embrace sampling concepts and procedures. The ...

  17. Irradiation chamber and sample changer for biological samples

    International Nuclear Information System (INIS)

    Kraft, G.; Daues, H.W.; Fischer, B.; Kopf, U.; Liebold, H.P.; Quis, D.; Stelzer, H.; Kiefer, J.; Schoepfer, F.; Schneider, E.

    1980-01-01

    This paper describes an irradiaton system with which living cells of different origin are irradiated with heavy ion beams (18 <- Z <- 92) at energies up to 10 MeV/amu. The system consists of a beam monitor connected to the vacuum system of the accelerator and the irradiation chamber, containing the biological samples under atmospheric pressure. The requirements and aims of the set up are discussed. The first results with saccharomyces cerevisiae and Chinese Hamster tissue cells are presented. (orig.)

  18. Phobos Sample Return: Next Approach

    Science.gov (United States)

    Zelenyi, Lev; Martynov, Maxim; Zakharov, Alexander; Korablev, Oleg; Ivanov, Alexey; Karabadzak, George

    The Martian moons still remain a mystery after numerous studies by Mars orbiting spacecraft. Their study cover three major topics related to (1) Solar system in general (formation and evolution, origin of planetary satellites, origin and evolution of life); (2) small bodies (captured asteroid, or remnants of Mars formation, or reaccreted Mars ejecta); (3) Mars (formation and evolution of Mars; Mars ejecta at the satellites). As reviewed by Galimov [2010] most of the above questions require the sample return from the Martian moon, while some (e.g. the characterization of the organic matter) could be also answered by in situ experiments. There is the possibility to obtain the sample of Mars material by sampling Phobos: following to Chappaz et al. [2012] a 200-g sample could contain 10-7 g of Mars surface material launched during the past 1 mln years, or 5*10-5 g of Mars material launched during the past 10 mln years, or 5*1010 individual particles from Mars, quantities suitable for accurate laboratory analyses. The studies of Phobos have been of high priority in the Russian program on planetary research for many years. Phobos-88 mission consisted of two spacecraft (Phobos-1, Phobos-2) and aimed the approach to Phobos at 50 m and remote studies, and also the release of small landers (long-living stations DAS). This mission implemented the program incompletely. It was returned information about the Martian environment and atmosphere. The next profect Phobos Sample Return (Phobos-Grunt) initially planned in early 2000 has been delayed several times owing to budget difficulties; the spacecraft failed to leave NEO in 2011. The recovery of the science goals of this mission and the delivery of the samples of Phobos to Earth remain of highest priority for Russian scientific community. The next Phobos SR mission named Boomerang was postponed following the ExoMars cooperation, but is considered the next in the line of planetary exploration, suitable for launch around 2022. A

  19. Statistics and sampling in transuranic studies

    International Nuclear Information System (INIS)

    Eberhardt, L.L.; Gilbert, R.O.

    1980-01-01

    The existing data on transuranics in the environment exhibit a remarkably high variability from sample to sample (coefficients of variation of 100% or greater). This chapter stresses the necessity of adequate sample size and suggests various ways to increase sampling efficiency. Objectives in sampling are regarded as being of great importance in making decisions as to sampling methodology. Four different classes of sampling methods are described: (1) descriptive sampling, (2) sampling for spatial pattern, (3) analytical sampling, and (4) sampling for modeling. A number of research needs are identified in the various sampling categories along with several problems that appear to be common to two or more such areas

  20. Superfund Site Information - Site Sampling Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — This asset includes Superfund site-specific sampling information including location of samples, types of samples, and analytical chemistry characteristics of...

  1. Controlled sample program publication No. 1: characterization of rock samples

    International Nuclear Information System (INIS)

    Ames, L.L.

    1978-10-01

    A description is presented of the methodology used and the geologic parameters measured on several rocks which are being used in round-robin laboratory and nuclide adsorption methodology experiments. Presently investigators from various laboratories are determining nuclide distribution coefficients utilizing numerous experimental techniques. Unfortunately, it appears that often the resultant data are dependent not only on the type of groundwater and rock utilized, but also on the experimentor or method used. The Controlled Sample Program is a WISAP (Waste Isolation Safety Assessment Program) attempt to resolve the apparent method and dependencies and to identify individual experimenter's bias. The rock samples characterized in an interlaboratory Kd methodology comparison program include Westerly granite, Argillaceous shale, Oolitic limestone, Sentinel Gap basalt, Conasauga shale, Climax Stock granite, anhydrite, Magenta dolomite and Culebra dolomite. Techniques used in the characterization include whole rock chemical analysis, X-ray diffraction, optical examination, electron microprobe elemental mapping, and chemical analysis of specific mineral phases. Surface areas were determined by the B.E.T. and ethylene glycol sorption methods. Cation exchange capacities were determined with 85 Sr, but were of questionable value for the high calcium rocks. A quantitative mineralogy was also estimated for each rock. Characteristics which have the potential of strongly affecting radionuclide Kd values such as the presence of sulfides, water-soluble, pH-buffering carbonates, glass, and ferrous iron were listed for each rock sample

  2. Adaptive Rate Sampling and Filtering Based on Level Crossing Sampling

    Directory of Open Access Journals (Sweden)

    Saeed Mian Qaisar

    2009-01-01

    Full Text Available The recent sophistications in areas of mobile systems and sensor networks demand more and more processing resources. In order to maintain the system autonomy, energy saving is becoming one of the most difficult industrial challenges, in mobile computing. Most of efforts to achieve this goal are focused on improving the embedded systems design and the battery technology, but very few studies target to exploit the input signal time-varying nature. This paper aims to achieve power efficiency by intelligently adapting the processing activity to the input signal local characteristics. It is done by completely rethinking the processing chain, by adopting a non conventional sampling scheme and adaptive rate filtering. The proposed approach, based on the LCSS (Level Crossing Sampling Scheme presents two filtering techniques, able to adapt their sampling rate and filter order by online analyzing the input signal variations. Indeed, the principle is to intelligently exploit the signal local characteristics—which is usually never considered—to filter only the relevant signal parts, by employing the relevant order filters. This idea leads towards a drastic gain in the computational efficiency and hence in the processing power when compared to the classical techniques.

  3. Authentication of forensic DNA samples.

    Science.gov (United States)

    Frumkin, Dan; Wasserstrom, Adam; Davidson, Ariane; Grafit, Arnon

    2010-02-01

    Over the past twenty years, DNA analysis has revolutionized forensic science, and has become a dominant tool in law enforcement. Today, DNA evidence is key to the conviction or exoneration of suspects of various types of crime, from theft to rape and murder. However, the disturbing possibility that DNA evidence can be faked has been overlooked. It turns out that standard molecular biology techniques such as PCR, molecular cloning, and recently developed whole genome amplification (WGA), enable anyone with basic equipment and know-how to produce practically unlimited amounts of in vitro synthesized (artificial) DNA with any desired genetic profile. This artificial DNA can then be applied to surfaces of objects or incorporated into genuine human tissues and planted in crime scenes. Here we show that the current forensic procedure fails to distinguish between such samples of blood, saliva, and touched surfaces with artificial DNA, and corresponding samples with in vivo generated (natural) DNA. Furthermore, genotyping of both artificial and natural samples with Profiler Plus((R)) yielded full profiles with no anomalies. In order to effectively deal with this problem, we developed an authentication assay, which distinguishes between natural and artificial DNA based on methylation analysis of a set of genomic loci: in natural DNA, some loci are methylated and others are unmethylated, while in artificial DNA all loci are unmethylated. The assay was tested on natural and artificial samples of blood, saliva, and touched surfaces, with complete success. Adopting an authentication assay for casework samples as part of the forensic procedure is necessary for maintaining the high credibility of DNA evidence in the judiciary system.

  4. Fetal scalp blood sampling during labor

    DEFF Research Database (Denmark)

    Chandraharan, Edwin; Wiberg, Nana

    2014-01-01

    Fetal cardiotocography is characterized by low specificity; therefore, in an attempt to ensure fetal well-being, fetal scalp blood sampling has been recommended by most obstetric societies in the case of a non-reassuring cardiotocography. The scientific agreement on the evidence for using fetal...... scalp blood sampling to decrease the rate of operative delivery for fetal distress is ambiguous. Based on the same studies, a Cochrane review states that fetal scalp blood sampling increases the rate of instrumental delivery while decreasing neonatal acidosis, whereas the National Institute of Health...... and Clinical Excellence guideline considers that fetal scalp blood sampling decreases instrumental delivery without differences in other outcome variables. The fetal scalp is supplied by vessels outside the skull below the level of the cranial vault, which is likely to be compressed during contractions...

  5. Inclusion of mobile phone numbers into an ongoing population health survey in New South Wales, Australia: design, methods, call outcomes, costs and sample representativeness.

    Science.gov (United States)

    Barr, Margo L; van Ritten, Jason J; Steel, David G; Thackway, Sarah V

    2012-11-22

    In Australia telephone surveys have been the method of choice for ongoing jurisdictional population health surveys. Although it was estimated in 2011 that nearly 20% of the Australian population were mobile-only phone users, the inclusion of mobile phone numbers into these existing landline population health surveys has not occurred. This paper describes the methods used for the inclusion of mobile phone numbers into an existing ongoing landline random digit dialling (RDD) health survey in an Australian state, the New South Wales Population Health Survey (NSWPHS). This paper also compares the call outcomes, costs and the representativeness of the resultant sample to that of the previous landline sample. After examining several mobile phone pilot studies conducted in Australia and possible sample designs (screening dual-frame and overlapping dual-frame), mobile phone numbers were included into the NSWPHS using an overlapping dual-frame design. Data collection was consistent, where possible, with the previous years' landline RDD phone surveys and between frames. Survey operational data for the frames were compared and combined. Demographic information from the interview data for mobile-only phone users, both, and total were compared to the landline frame using χ2 tests. Demographic information for each frame, landline and the mobile-only (equivalent to a screening dual frame design), and the frames combined (with appropriate overlap adjustment) were compared to the NSW demographic profile from the 2011 census using χ2 tests. In the first quarter of 2012, 3395 interviews were completed with 2171 respondents (63.9%) from the landline frame (17.6% landline only) and 1224 (36.1%) from the mobile frame (25.8% mobile only). Overall combined response, contact and cooperation rates were 33.1%, 65.1% and 72.2% respectively. As expected from previous research, the demographic profile of the mobile-only phone respondents differed most (more that were young, males, Aboriginal

  6. Representative mass reduction in sampling

    DEFF Research Database (Denmark)

    Petersen, Lars; Esbensen, Harry Kim; Dahl, Casper Kierulf

    2004-01-01

    We here present a comprehensive survey of current mass reduction principles and hardware available in the current market. We conduct a rigorous comparison study of the performance of 17 field and/or laboratory instruments or methods which are quantitatively characterized (and ranked) for accuracy...... dividers, the Boerner Divider, the ??spoon method??, alternate/fractional shoveling and grab sampling. Only devices based on riffle splitting principles (static or rotational) passes the ultimate representativity test (with minor, but significant relative differences). Grab sampling, the overwhelmingly...... most often used mass reduction method, performs appallingly?its use must be discontinued (with the singular exception for completely homogenized fine powders). Only proper mass reduction (i.e. carried out in complete compliance with all appropriate design principles, maintenance and cleaning rules) can...

  7. Environmental surveillance master sampling schedule

    Energy Technology Data Exchange (ETDEWEB)

    Bisping, L E

    1992-01-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). This document contains the planned schedule for routine sample collection for the Surface Environmental Surveillance Project (SESP) and Ground-Water Monitoring Project. Samples for radiological analyses include Air-Particulate Filter, gases and vapor; Water/Columbia River, Onsite Pond, Spring, Irrigation, and Drinking; Foodstuffs/Animal Products including Whole Milk, Poultry and Eggs, and Beef; Foodstuffs/Produce including Leafy Vegetables, Vegetables, and Fruit; Foodstuffs/Farm Products including Wine, Wheat and Alfalfa; Wildlife; Soil; Vegetation; and Sediment. Direct Radiation Measurements include Terrestrial Locations, Columbia River Shoreline Locations, and Onsite Roadway, Railway and Aerial, Radiation Surveys.

  8. Sampling vs. taking some - 59349

    International Nuclear Information System (INIS)

    Francois-Bongarcon, D.

    2012-01-01

    Collecting a sample is a delicate task that is Not naively equivalent to simply 'taking some of the material'. The question examined is: 'What is it exactly?' The problem of sampling in general, and for nuclear decontamination in particular, is properly defined. A theory is presented (Gy's Theory of Sampling, a.k.a. TOS) that brings all the answers and allows us to put them to work. The author draws form his lifelong experience in research, teaching and practical applications in this domain to emphasize the critical odds (i.e. risks) of not taking sampling explicitly into account when assessing grades and concentrations. The evolution of the acceptance of this theory in the nuclear industry is finally illustrated, and a hopeful glimpse into the future concludes the presentation. Equally interesting, however, besides what has already been achieved at the CEA along these years, is the realization of what could not be done with TOS, and therefore had to be treated in some other ways - e.g. using mapping tools (geostatistical). It is one the great side-advantages of using a consistent theory that it warns you, before it is too late, that what you are trying to do will not work: TOS, indeed, much like its Geo-statistics sister, besides preventing many a disaster, can provide pragmatic lessons in scientific humility that are best not being left ignored. In conclusion, there are great tools out there, such as TOS, that are well worth investing into, and that our community should be much more attuned to. (author)

  9. Characterization of superconducting multilayers samples

    CERN Document Server

    Antoine, C Z; Berry, S; Bouat, S; Jacquot, J F; Villegier, J C; Lamura, G; Gurevich, A

    2009-01-01

    Best RF bulk niobium accelerating cavities have nearly reached their ultimate limits at rf equatorial magnetic field H  200 mT close to the thermodynamic critical field Hc. In 2006 Gurevich proposed to use nanoscale layers of superconducting materials with high values of Hc > HcNb for magnetic shielding of bulk niobium to increase the breakdown magnetic field inside SC RF cavities [1]. Depositing good quality layers inside a whole cavity is rather difficult but we have sputtered high quality samples by applying the technique used for the preparation of superconducting electronics circuits and characterized these samples by X-ray reflectivity, dc resistivity (PPMS) and dc magnetization (SQUID). Dc magnetization curves of a 250 nm thick Nb film have been measured, with and without a magnetron sputtered coating of a single or multiple stack of 15 nm MgO and 25 nm NbN layers. The Nb samples with/without the coating clearly exhibit different behaviors. Because SQUID measurements are influenced by edge an...

  10. The large sample size fallacy.

    Science.gov (United States)

    Lantz, Björn

    2013-06-01

    Significance in the statistical sense has little to do with significance in the common practical sense. Statistical significance is a necessary but not a sufficient condition for practical significance. Hence, results that are extremely statistically significant may be highly nonsignificant in practice. The degree of practical significance is generally determined by the size of the observed effect, not the p-value. The results of studies based on large samples are often characterized by extreme statistical significance despite small or even trivial effect sizes. Interpreting such results as significant in practice without further analysis is referred to as the large sample size fallacy in this article. The aim of this article is to explore the relevance of the large sample size fallacy in contemporary nursing research. Relatively few nursing articles display explicit measures of observed effect sizes or include a qualitative discussion of observed effect sizes. Statistical significance is often treated as an end in itself. Effect sizes should generally be calculated and presented along with p-values for statistically significant results, and observed effect sizes should be discussed qualitatively through direct and explicit comparisons with the effects in related literature. © 2012 Nordic College of Caring Science.

  11. [Saarland Growth Study: sampling design].

    Science.gov (United States)

    Danker-Hopfe, H; Zabransky, S

    2000-01-01

    The use of reference data to evaluate the physical development of children and adolescents is part of the daily routine in the paediatric ambulance. The construction of such reference data is based on the collection of extensive reference data. There are different kinds of reference data: cross sectional references, which are based on data collected from a big representative cross-sectional sample of the population, longitudinal references, which are based on follow-up surveys of usually smaller samples of individuals from birth to maturity, and mixed longitudinal references, which are a combination of longitudinal and cross-sectional reference data. The advantages and disadvantages of the different methods of data collection and the resulting reference data are discussed. The Saarland Growth Study was conducted for several reasons: growth processes are subject to secular changes, there are no specific reference data for children and adolescents from this part of the country and the growth charts in use in the paediatric praxis are possibly not appropriate any more. Therefore, the Saarland Growth Study served two purposes a) to create actual regional reference data and b) to create a database for future studies on secular trends in growth processes of children and adolescents from Saarland. The present contribution focusses on general remarks on the sampling design of (cross-sectional) growth surveys and its inferences for the design of the present study.

  12. Multielemental analysis of milk samples

    International Nuclear Information System (INIS)

    Omar Al-Dayel; Jameel Al-Hefne; Didarul A Chowdhury; Turki Al-Ajyan

    2002-01-01

    Milk is a basic food since it provides essential nutrients (proteins, lipids, carbohydrates) and micronutrients (minerals, Vitamins, enzymes). In fact, in formula milk essential elements have been usually added in order to satisfy nutritional requirements. However, too high additions of these elements can produce detrimental effects on human health. More important, milk can also constitute a source of exposure to toxic elements, especially dangerous for infants. Method is presented for the multielemental analysis of a wide range of elements in milk samples. The aim of this work is the development of a multielemental method for the analysis of major, minor and trace essential and toxic elements in milk. Several milk samples with different origins were collected from the Saudi Arabia markets and analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). For preparation of the samples for analysis, they were digested by closed vessel microwave digestion system with H 2 O 2 /HNO 3 . About 40 elements were determined. A reference material was analysed for the validation of the proposed method. (Author)

  13. Focused conformational sampling in proteins

    Science.gov (United States)

    Bacci, Marco; Langini, Cassiano; Vymětal, Jiří; Caflisch, Amedeo; Vitalis, Andreas

    2017-11-01

    A detailed understanding of the conformational dynamics of biological molecules is difficult to obtain by experimental techniques due to resolution limitations in both time and space. Computer simulations avoid these in theory but are often too short to sample rare events reliably. Here we show that the progress index-guided sampling (PIGS) protocol can be used to enhance the sampling of rare events in selected parts of biomolecules without perturbing the remainder of the system. The method is very easy to use as it only requires as essential input a set of several features representing the parts of interest sufficiently. In this feature space, new states are discovered by spontaneous fluctuations alone and in unsupervised fashion. Because there are no energetic biases acting on phase space variables or projections thereof, the trajectories PIGS generates can be analyzed directly in the framework of transition networks. We demonstrate the possibility and usefulness of such focused explorations of biomolecules with two loops that are part of the binding sites of bromodomains, a family of epigenetic "reader" modules. This real-life application uncovers states that are structurally and kinetically far away from the initial crystallographic structures and are also metastable. Representative conformations are intended to be used in future high-throughput virtual screening campaigns.

  14. Catch me if you can: Comparing ballast water sampling skids to traditional net sampling

    Science.gov (United States)

    Bradie, Johanna; Gianoli, Claudio; Linley, Robert Dallas; Schillak, Lothar; Schneider, Gerd; Stehouwer, Peter; Bailey, Sarah

    2018-03-01

    With the recent ratification of the International Convention for the Control and Management of Ships' Ballast Water and Sediments, 2004, it will soon be necessary to assess ships for compliance with ballast water discharge standards. Sampling skids that allow the efficient collection of ballast water samples in a compact space have been developed for this purpose. We ran 22 trials on board the RV Meteor from June 4-15, 2015 to evaluate the performance of three ballast water sampling devices (traditional plankton net, Triton sampling skid, SGS sampling skid) for three organism size classes: ≥ 50 μm, ≥ 10 μm to Natural sea water was run through the ballast water system and untreated samples were collected using paired sampling devices. Collected samples were analyzed in parallel by multiple analysts using several different analytic methods to quantify organism concentrations. To determine whether there were differences in the number of viable organisms collected across sampling devices, results were standardized and statistically treated to filter out other sources of variability, resulting in an outcome variable representing the mean difference in measurements that can be attributed to sampling devices. These results were tested for significance using pairwise Tukey contrasts. Differences in organism concentrations were found in 50% of comparisons between sampling skids and the plankton net for ≥ 50 μm, and ≥ 10 μm to < 50 μm size classes, with net samples containing either higher or lower densities. There were no differences for < 10 μm organisms. Future work will be required to explicitly examine the potential effects of flow velocity, sampling duration, sampled volume, and organism concentrations on sampling device performance.

  15. Synchronizing data from irregularly sampled sensors

    Science.gov (United States)

    Uluyol, Onder

    2017-07-11

    A system and method include receiving a set of sampled measurements for each of multiple sensors, wherein the sampled measurements are at irregular intervals or different rates, re-sampling the sampled measurements of each of the multiple sensors at a higher rate than one of the sensor's set of sampled measurements, and synchronizing the sampled measurements of each of the multiple sensors.

  16. Absorption factor for cylindrical samples

    International Nuclear Information System (INIS)

    Sears, V.F.

    1984-01-01

    The absorption factor for the scattering of X-rays or neutrons in cylindrical samples is calculated by numerical integration for the case in which the absorption coefficients of the incident and scattered beams are not equal. An extensive table of values having an absolute accuracy of 10 -4 is given in a companion report [Sears (1983). Atomic Energy of Canada Limited, Report No. AECL-8176]. In the present paper an asymptotic expression is derived for the absorption factor which can be used with an error of less than 10 -3 for most cases of interest in both neutron inelastic scattering and neutron diffraction in crystals. (Auth.)

  17. Reconstructing pictures from sampled data

    International Nuclear Information System (INIS)

    Bone, D.; Pullan, B.R.; Taylor, C.J.

    1973-01-01

    Corrections for two important degrading effects in gamma ray imaging systems are described. The adaptive local operator has the advantage that given the assumptions of the method the optimum correction is made for both sources of error simultaneously. The probability operator method although less soundly based in classical signal processing theory does make more use of the known statistical properties of possible inputs and consequently might make a better estimate of the true sample values. A separate correction would need to be made for blurring effects. The initial results indicate that the methods are worthy of further investigation

  18. Statistical sampling for holdup measurement

    International Nuclear Information System (INIS)

    Picard, R.R.; Pillay, K.K.S.

    1986-01-01

    Nuclear materials holdup is a serious problem in many operating facilities. Estimating amounts of holdup is important for materials accounting and, sometimes, for process safety. Clearly, measuring holdup in all pieces of equipment is not a viable option in terms of time, money, and radiation exposure to personnel. Furthermore, 100% measurement is not only impractical but unnecessary for developing estimated values. Principles of statistical sampling are valuable in the design of cost effective holdup monitoring plans and in qualifying uncertainties in holdup estimates. The purpose of this paper is to describe those principles and to illustrate their use

  19. IRAS bright galaxy sample. II. The sample and luminosity function

    International Nuclear Information System (INIS)

    Soifer, B.T.; Sanders, D.B.; Neugebauer, G.; Madore, B.F.; Danielson, G.E.; David Dunlap Observatory, Richmond Hill, Canada; Palomar Observatory; California Institute of Technology, Pasadena)

    1987-01-01

    A statistically complete sample of 324 of the brightest infrared galaxies discovered at 60 microns in the IRAS all-sky survey is described. The results show that far-infrared emission is a significant luminosity component in the local universe, representing 25 percent of the luminosity emitted by stars in the same volume. Above 10 to the 11th solar luminosities, the infrared luminous galaxies are the dominant population of objects in the universe, being as numerous as the Seyfert galaxies and more numerous than quasars at higher luminosities. The infrared luminosity appears to be independent of the optical luminosity of galaxies. Most infrared bright galaxies appear to require much of the interstellar matter to be contributing to the observed infrared luminosity. Approximately 60-80 percent of the far-infrared luminosity of the local universe can be attributed, directly or indirectly, to recent or ongoing star formation. 67 references

  20. Sampling the Mouse Hippocampal Dentate Gyrus

    Directory of Open Access Journals (Sweden)

    Lisa Basler

    2017-12-01

    Full Text Available Sampling is a critical step in procedures that generate quantitative morphological data in the neurosciences. Samples need to be representative to allow statistical evaluations, and samples need to deliver a precision that makes statistical evaluations not only possible but also meaningful. Sampling generated variability should, e.g., not be able to hide significant group differences from statistical detection if they are present. Estimators of the coefficient of error (CE have been developed to provide tentative answers to the question if sampling has been “good enough” to provide meaningful statistical outcomes. We tested the performance of the commonly used Gundersen-Jensen CE estimator, using the layers of the mouse hippocampal dentate gyrus as an example (molecular layer, granule cell layer and hilus. We found that this estimator provided useful estimates of the precision that can be expected from samples of different sizes. For all layers, we found that a smoothness factor (m of 0 generally provided better estimates than an m of 1. Only for the combined layers, i.e., the entire dentate gyrus, better CE estimates could be obtained using an m of 1. The orientation of the sections impacted on CE sizes. Frontal (coronal sections are typically most efficient by providing the smallest CEs for a given amount of work. Applying the estimator to 3D-reconstructed layers and using very intense sampling, we observed CE size plots with m = 0 to m = 1 transitions that should also be expected but are not often observed in real section series. The data we present also allows the reader to approximate the sampling intervals in frontal, horizontal or sagittal sections that provide CEs of specified sizes for the layers of the mouse dentate gyrus.

  1. Evaluating outcome-correlated recruitment and geographic recruitment bias in a respondent-driven sample of people who inject drugs in Tijuana, Mexico.

    Science.gov (United States)

    Rudolph, Abby E; Gaines, Tommi L; Lozada, Remedios; Vera, Alicia; Brouwer, Kimberly C

    2014-12-01

    Respondent-driven sampling's (RDS) widespread use and reliance on untested assumptions suggests a need for new exploratory/diagnostic tests. We assessed geographic recruitment bias and outcome-correlated recruitment among 1,048 RDS-recruited people who inject drugs (Tijuana, Mexico). Surveys gathered demographics, drug/sex behaviors, activity locations, and recruiter-recruit pairs. Simulations assessed geographic and network clustering of active syphilis (RPR titers ≥1:8). Gender-specific predicted probabilities were estimated using logistic regression with GEE and robust standard errors. Active syphilis prevalence was 7 % (crude: men = 5.7 % and women = 16.6 %; RDS-adjusted: men = 6.7 % and women = 7.6 %). Syphilis clustered in the Zona Norte, a neighborhood known for drug and sex markets. Network simulations revealed geographic recruitment bias and non-random recruitment by syphilis status. Gender-specific prevalence estimates accounting for clustering were highest among those living/working/injecting/buying drugs in the Zona Norte and directly/indirectly connected to syphilis cases (men: 15.9 %, women: 25.6 %) and lowest among those with neither exposure (men: 3.0 %, women: 6.1 %). Future RDS analyses should assess/account for network and spatial dependencies.

  2. [HPV primary test in the cervical cancer screening: reproducibility assessment and investigation on cytological outcome of Hybrid Capture 2 borderline samples].

    Science.gov (United States)

    Burroni, Elena; Sani, Cristina; Bisanzi, Simonetta; Ocello, Cristina

    2016-01-01

    to evaluate the reproducibility of the High-Risk Hybrid Capture 2 (HC2-HR, Qiagen) test within the frame of cervical cancer screening with HPV, for samples with values very close to the cut-off (borderline), that is 0.80≤RLU/CO≤0.99 (RLU/CO: relative light units/cut-off) and to assess any possible presence of high grade lesions. all borderline samples collected from January 2014 to August 2015 were repeated with HR-HC2 test within two weeks from the first test. For HPV-positive samples, cytology and colposcopy results (if present) were analysed. national and international directions recommend the use of HPV testing as a primary test for cervical cancer screening for women aged 30/34-64 years. In Tuscany Region (Central Italy) the primary screening with HPV test was introduced in 2013 and the HPV test currently used, HR-HC2, has a positive cut-off≥1 RLU/CO. proportion of HPV-positive tests at repetition, then stratified by type of material (ThinPrep, STM) and for the following subclasses of RLU/CO: 0.80-0.89 and 0.90-0.99. 253 samples were borderline at first test with HR-HC2 (about 0.4% of all samples tested). About 83% (209/253) of the samples was confirmed to be negative at the HPV test repetition: 88% for RLU/CO=0.80-0.89 and 76% for RLU/CO=0.90-0.99 (p-value=0.014). Median RLU/CO value of 44 HPV-positive samples at repetition is 1.4, with a maximum RLU/CO value of 16.7. In addition, 90% of HPV-positive samples at repetition has a RLU/CO values below or equal to 3.6. Even the used sampling system affects reproducibility: 26.4% (33/125) of the samples resulted positive at the repetition were in ThinPrep vs. 8.6% (11/128) of those in STM (p-valuecut-off (0.90-0.99), confirming the intrinsic limit to all analytical methods near to the cut-off. Moreover, even if the difference in reproducibility between the two systems of sampling is statistically significant, in samples that resulted positive at repetition high-grade lesions were not found at the time of HPV

  3. TRU waste-sampling program

    International Nuclear Information System (INIS)

    Warren, J.L.; Zerwekh, A.

    1985-08-01

    As part of a TRU waste-sampling program, Los Alamos National Laboratory retrieved and examined 44 drums of 238 Pu- and 239 Pu-contaminated waste. The drums ranged in age from 8 months to 9 years. The majority of drums were tested for pressure, and gas samples withdrawn from the drums were analyzed by a mass spectrometer. Real-time radiography and visual examination were used to determine both void volumes and waste content. Drum walls were measured for deterioration, and selected drum contents were reassayed for comparison with original assays and WIPP criteria. Each drum tested at atmospheric pressure. Mass spectrometry revealed no problem with 239 Pu-contaminated waste, but three 8-month-old drums of 238 Pu-contaminated waste contained a potentially hazardous gas mixture. Void volumes fell within the 81 to 97% range. Measurements of drum walls showed no significant corrosion or deterioration. All reassayed contents were within WIPP waste acceptance criteria. Five of the drums opened and examined (15%) could not be certified as packaged. Three contained free liquids, one had corrosive materials, and one had too much unstabilized particulate. Eleven drums had the wrong (or not the most appropriate) waste code. In many cases, disposal volumes had been inefficiently used. 2 refs., 23 figs., 7 tabs

  4. Cold SQUIDs and hot samples

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T.S.C. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley national Lab., CA (United States). Materials Sciences Div.

    1997-05-01

    Low transition temperature (low-{Tc}) and high-{Tc} Superconducting QUantum Interference Devices (SQUIDs) have been used to perform high-resolution magnetic measurements on samples whose temperatures are much higher than the operating temperatures of the devices. Part 1 of this work focuses on measurements of the rigidity of flux vortices in high-{Tc} superconductors using two low-{Tc} SQUIDs, one on either side of a thermally-insulated sample. The correlation between the signals of the SQUIDs is a direct measure of the extent of correlation between the movements of opposite ends of vortices. These measurements were conducted under the previously-unexplored experimental conditions of nominally-zero applied magnetic field, such that vortex-vortex interactions were unimportant, and with zero external current. At specific temperatures, the authors observed highly-correlated noise sources, suggesting that the vortices moved as rigid rods. At other temperatures, the noise was mostly uncorrelated, suggesting that the relevant vortices were pinned at more than one point along their length. Part 2 describes the design, construction, performance, and applications of a scanning high-{Tc} SQUID microscope optimized for imaging room-temperature objects with very high spatial resolution and magnetic source sensitivity.

  5. Cold SQUIDs and hot samples

    International Nuclear Information System (INIS)

    Lee, T.S.C.; Lawrence Berkeley national Lab., CA

    1997-05-01

    Low transition temperature (low-T c ) and high-T c Superconducting QUantum Interference Devices (SQUIDs) have been used to perform high-resolution magnetic measurements on samples whose temperatures are much higher than the operating temperatures of the devices. Part 1 of this work focuses on measurements of the rigidity of flux vortices in high-T c superconductors using two low-T c SQUIDs, one on either side of a thermally-insulated sample. The correlation between the signals of the SQUIDs is a direct measure of the extent of correlation between the movements of opposite ends of vortices. These measurements were conducted under the previously-unexplored experimental conditions of nominally-zero applied magnetic field, such that vortex-vortex interactions were unimportant, and with zero external current. At specific temperatures, the authors observed highly-correlated noise sources, suggesting that the vortices moved as rigid rods. At other temperatures, the noise was mostly uncorrelated, suggesting that the relevant vortices were pinned at more than one point along their length. Part 2 describes the design, construction, performance, and applications of a scanning high-T c SQUID microscope optimized for imaging room-temperature objects with very high spatial resolution and magnetic source sensitivity

  6. Electron holography of biological samples.

    Science.gov (United States)

    Simon, P; Lichte, H; Formanek, P; Lehmann, M; Huhle, R; Carrillo-Cabrera, W; Harscher, A; Ehrlich, H

    2008-01-01

    In this paper, we summarise the development of off-axis electron holography on biological samples starting in 1986 with the first results on ferritin from the group of Tonomura. In the middle of the 1990s strong interest was evoked, but then stagnation took place because the results obtained at that stage did not reach the contrast and the resolution achieved by conventional electron microscopy. To date, there exist only a few ( approximately 12) publications on electron holography of biological objects, thus this topic is quite small and concise. The reason for this could be that holography is mostly established in materials science by physicists. Therefore, applications for off-axis holography were powerfully pushed forward in the area of imaging, e.g. electric or magnetic micro- and nanofields. Unstained biological systems investigated by means of off-axis electron holography up to now are ferritin, tobacco mosaic virus, a bacterial flagellum, T5 bacteriophage virus, hexagonal packed intermediate layer of bacteria and the Semliki Forest virus. New results of the authors on collagen fibres and surface layer of bacteria, the so-called S-layer 2D crystal lattice are presented in this review. For the sake of completeness, we will shortly discuss in-line holography of biological samples and off-axis holography of materials related to biological systems, such as biomaterial composites or magnetotactic bacteria.

  7. NASA's Aerosol Sampling Experiment Summary

    Science.gov (United States)

    Meyer, Marit E.

    2016-01-01

    In a spacecraft cabin environment, the size range of indoor aerosols is much larger and they persist longer than on Earth because they are not removed by gravitational settling. A previous aerosol experiment in 1991 documented that over 90 of the mass concentration of particles in the NASA Space Shuttle air were between 10 m and 100 m based on measurements with a multi-stage virtual impactor and a nephelometer (Liu et al. 1991). While the now-retired Space Shuttle had short duration missions (less than two weeks), the International Space Station (ISS) has been continually inhabited by astronauts for over a decade. High concentrations of inhalable particles on ISS are potentially responsible for crew complaints of respiratory and eye irritation and comments about 'dusty' air. Air filtration is the current control strategy for airborne particles on the ISS, and filtration modeling, performed for engineering and design validation of the air revitalization system in ISS, predicted that PM requirements would be met. However, aerosol monitoring has never been performed on the ISS to verify PM levels. A flight experiment is in preparation which will provide data on particulate matter in ISS ambient air. Particles will be collected with a thermophoretic sampler as well as with passive samplers which will extend the particle size range of sampling. Samples will be returned to Earth for chemical and microscopic analyses, providing the first aerosol data for ISS ambient air.

  8. Estimating Sample Size for Usability Testing

    Directory of Open Access Journals (Sweden)

    Alex Cazañas

    2017-02-01

    Full Text Available One strategy used to assure that an interface meets user requirements is to conduct usability testing. When conducting such testing one of the unknowns is sample size. Since extensive testing is costly, minimizing the number of participants can contribute greatly to successful resource management of a project. Even though a significant number of models have been proposed to estimate sample size in usability testing, there is still not consensus on the optimal size. Several studies claim that 3 to 5 users suffice to uncover 80% of problems in a software interface. However, many other studies challenge this assertion. This study analyzed data collected from the user testing of a web application to verify the rule of thumb, commonly known as the “magic number 5”. The outcomes of the analysis showed that the 5-user rule significantly underestimates the required sample size to achieve reasonable levels of problem detection.

  9. An improved selective sampling method

    International Nuclear Information System (INIS)

    Miyahara, Hiroshi; Iida, Nobuyuki; Watanabe, Tamaki

    1986-01-01

    The coincidence methods which are currently used for the accurate activity standardisation of radio-nuclides, require dead time and resolving time corrections which tend to become increasingly uncertain as countrates exceed about 10 K. To reduce the dependence on such corrections, Muller, in 1981, proposed the selective sampling method using a fast multichannel analyser (50 ns ch -1 ) for measuring the countrates. It is, in many ways, more convenient and possibly potentially more reliable to replace the MCA with scalers and a circuit is described employing five scalers; two of them serving to measure the background correction. Results of comparisons using our new method and the coincidence method for measuring the activity of 60 Co sources yielded agree-ment within statistical uncertainties. (author)

  10. Brine Sampling and Evaluation Program

    International Nuclear Information System (INIS)

    Deal, D.E.; Case, J.B.; Deshler, R.M.; Drez, P.E.; Myers, J.; Tyburski, J.R.

    1987-12-01

    The Brine Sampling and Evaluation Program (BSEP) Phase II Report is an interim report which updates the data released in the BSEP Phase I Report. Direct measurements and observations of the brine that seeps into the WIPP repository excavations were continued through the period between August 1986 and July 1987. That data is included in Appendix A, which extends the observation period for some locations to approximately 900 days. Brine observations at 87 locations are presented in this report. Although WIPP underground workings are considered ''dry,'' small amounts of brine are present. Part of that brine migrates into the repository in response to pressure gradients at essentially isothermal conditions. The data presented in this report is a continuation of moisture content studies of the WIPP facility horizon that were initiated in 1982, as soon as underground drifts began to be excavated. Brine seepages are manifested by salt efflorescences, moist areas, and fluid accumulations in drillholes. 35 refs., 6 figs., 11 tabs

  11. [A meta-analysis of the impact of sample, kind of outcome measurement and time of follow up on occupational re-integration after vocational retraining].

    Science.gov (United States)

    Streibelt, M; Egner, U

    2012-12-01

    Vocational Rehabilitation (VR) is an essential element of intervention to rehabilitate people with work disability due to chronic diseases. The activities are heterogeneous; of particular importance in the rehabilitation process is vocational retraining. These interventions are cost-intensive, take very long and have a decisive impact on the main goal, the return to work (RTW). However, vocational retraining is conducted under different settings: The question is to what extent this leads to specific methodical implications of RTW measurement that have an impact on the level of RTW. The analysis was concentrated on the main outcome RTW after vocational retraining. A structured review was conducted of all German-language publications from 2005 to 2010 which report an RTW quota after vocational retraining. The main methodical conditions were: kind of RTW measurement (point in time rate vs. cumulative course rate), time of follow-up in years, and sample definition (all participants vs. participants with regular completion of retraining, RC). The impact of these conditions on the level of RTW was predicted by using a meta-regression model. The time of follow-up was standardized on the mean (1 year). 20 publications from 10 studies were included in the analysis. In all, 23 RTW quota were observed, from which 22 were included in the regression model. A positive impact on the level of RTW was identified for reduction of the sample to participants with RC (b=10.04; p=0.001), the time of follow-up (b=5.47; p=0.052) and, by trend, the interaction of the kind of RTW measurement and time of follow-up (b=6.32; p=0.090). There was no significance given for the main effect of kind of RTW measurement (p=0.787). The model fit was calculated with an adjusted R2=75.17%. The level of RTW given in the publications is very heterogeneous, but a major part of the variance was explained by the 3 methodical conditions we examined. Based on this, a classification system for RTW measurement

  12. Methodology Series Module 5: Sampling Strategies.

    Science.gov (United States)

    Setia, Maninder Singh

    2016-01-01

    Once the research question and the research design have been finalised, it is important to select the appropriate sample for the study. The method by which the researcher selects the sample is the ' Sampling Method'. There are essentially two types of sampling methods: 1) probability sampling - based on chance events (such as random numbers, flipping a coin etc.); and 2) non-probability sampling - based on researcher's choice, population that accessible & available. Some of the non-probability sampling methods are: purposive sampling, convenience sampling, or quota sampling. Random sampling method (such as simple random sample or stratified random sample) is a form of probability sampling. It is important to understand the different sampling methods used in clinical studies and mention this method clearly in the manuscript. The researcher should not misrepresent the sampling method in the manuscript (such as using the term ' random sample' when the researcher has used convenience sample). The sampling method will depend on the research question. For instance, the researcher may want to understand an issue in greater detail for one particular population rather than worry about the ' generalizability' of these results. In such a scenario, the researcher may want to use ' purposive sampling' for the study.

  13. 40 CFR 1065.150 - Continuous sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Continuous sampling. 1065.150 Section... ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.150 Continuous sampling. You may use continuous sampling techniques for measurements that involve raw or dilute sampling. Make sure continuous sampling...

  14. Methodology series module 5: Sampling strategies

    Directory of Open Access Journals (Sweden)

    Maninder Singh Setia

    2016-01-01

    Full Text Available Once the research question and the research design have been finalised, it is important to select the appropriate sample for the study. The method by which the researcher selects the sample is the 'Sampling Method'. There are essentially two types of sampling methods: 1 probability sampling – based on chance events (such as random numbers, flipping a coin etc.; and 2 non-probability sampling – based on researcher's choice, population that accessible & available. Some of the non-probability sampling methods are: purposive sampling, convenience sampling, or quota sampling. Random sampling method (such as simple random sample or stratified random sample is a form of probability sampling. It is important to understand the different sampling methods used in clinical studies and mention this method clearly in the manuscript. The researcher should not misrepresent the sampling method in the manuscript (such as using the term 'random sample' when the researcher has used convenience sample. The sampling method will depend on the research question. For instance, the researcher may want to understand an issue in greater detail for one particular population rather than worry about the 'generalizability' of these results. In such a scenario, the researcher may want to use 'purposive sampling' for the study.

  15. Micro-organism distribution sampling for bioassays

    Science.gov (United States)

    Nelson, B. A.

    1975-01-01

    Purpose of sampling distribution is to characterize sample-to-sample variation so statistical tests may be applied, to estimate error due to sampling (confidence limits) and to evaluate observed differences between samples. Distribution could be used for bioassays taken in hospitals, breweries, food-processing plants, and pharmaceutical plants.

  16. Sampling bias in climate-conflict research

    Science.gov (United States)

    Adams, Courtland; Ide, Tobias; Barnett, Jon; Detges, Adrien

    2018-03-01

    Critics have argued that the evidence of an association between climate change and conflict is flawed because the research relies on a dependent variable sampling strategy1-4. Similarly, it has been hypothesized that convenience of access biases the sample of cases studied (the `streetlight effect'5). This also gives rise to claims that the climate-conflict literature stigmatizes some places as being more `naturally' violent6-8. Yet there has been no proof of such sampling patterns. Here we test whether climate-conflict research is based on such a biased sample through a systematic review of the literature. We demonstrate that research on climate change and violent conflict suffers from a streetlight effect. Further, studies which focus on a small number of cases in particular are strongly informed by cases where there has been conflict, do not sample on the independent variables (climate impact or risk), and hence tend to find some association between these two variables. These biases mean that research on climate change and conflict primarily focuses on a few accessible regions, overstates the links between both phenomena and cannot explain peaceful outcomes from climate change. This could result in maladaptive responses in those places that are stigmatized as being inherently more prone to climate-induced violence.

  17. Maternal outcomes of term breech presentation delivery: impact of successful external cephalic version in a nationwide sample of delivery admissions in the United States.

    Science.gov (United States)

    Weiniger, Carolyn F; Lyell, Deirdre J; Tsen, Lawrence C; Butwick, Alexander J; Shachar, BatZion; Callaghan, William M; Creanga, Andreea A; Bateman, Brian T

    2016-07-08

    We aimed to define the frequency and predictors of successful external cephalic version in a nationally-representative cohort of women with breech presentations and to compare maternal outcomes associated with successful external cephalic version versus persistent breech presentation. Using the Nationwide Inpatient Sample, a United States healthcare utilization database, we identified delivery admissions between 1998 and 2011 for women who had successful external cephalic version or persistent breech presentation (including unsuccessful or no external cephalic version attempt) at term. Multivariable logistic regression identified patient and hospital-level factors associated with successful external cephalic version. Maternal outcomes were compared between women who had successful external cephalic version versus persistent breech. Our study cohort comprised 1,079,576 delivery admissions with breech presentation; 56,409 (5.2 %) women underwent successful external cephalic version and 1,023,167 (94.8 %) women had persistent breech presentation at the time of delivery. The rate of cesarean delivery was lower among women who had successful external cephalic version compared to those with persistent breech (20.2 % vs. 94.9 %; p external cephalic version were also less likely to experience several measures of significant maternal morbidity including endometritis (adjusted Odds Ratio (aOR) = 0.36, 95 % Confidence Interval (CI) 0.24-0.52), sepsis (aOR = 0.35, 95 % CI 0.24-0.51) and length of stay > 7 days (aOR = 0.53, 95 % CI 0.40-0.70), but had a higher risk of chorioamnionitis (aOR = 1.83, 95 % CI 1.54-2.17). Overall a low proportion of women with breech presentation undergo successful external cephalic version, and it is associated with significant reduction in the frequency of cesarean delivery and a number of measures of maternal morbidity. Increased external cephalic version use may be an important approach to mitigate the high rate of

  18. Equipment for collecting samples of radioactive solutions

    International Nuclear Information System (INIS)

    Raggenbass, A.; Fradin, J.; Joubert, G.

    1958-01-01

    The authors present an equipment aimed at collecting samples of fission products to perform radio-chemical analysis. As the sample must have a total activity between 1 and 50 micro-Curie, this installation comprises a sampling system and a dilution device which aims at bringing the sample to the suitable activity. Samples are collected by means of needles. The sample reproducibility is discussed. The dilution device is described

  19. Methodology Series Module 5: Sampling Strategies

    OpenAIRE

    Setia, Maninder Singh

    2016-01-01

    Once the research question and the research design have been finalised, it is important to select the appropriate sample for the study. The method by which the researcher selects the sample is the ? Sampling Method?. There are essentially two types of sampling methods: 1) probability sampling ? based on chance events (such as random numbers, flipping a coin etc.); and 2) non-probability sampling ? based on researcher's choice, population that accessible & available. Some of the non-probabilit...

  20. Towards Cost-efficient Sampling Methods

    OpenAIRE

    Peng, Luo; Yongli, Li; Chong, Wu

    2014-01-01

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

  1. Physical sampling for site and waste characterization

    International Nuclear Information System (INIS)

    Bonnough, T.L.

    1996-01-01

    Physical sampling plays a basic role in high-level radioactive waste management program effort. The term ''physical sampling'' used here means collecting tangible, physical samples of soil, water, air, waste streams, or other materials. The industry defines the term ''physical sampling'' broadly to include measurements of physical conditions such as temperature, wind conditions, and pH, which are also often taken in a sample collection effort. Most environmental compliance actions are supported by the results of taking, recording, and analyzing physical samples and the measurements of physical conditions taken in association with sample collecting. Therefore, the when and how to take samples is needed to be known and planned

  2. Methodology Series Module 5: Sampling Strategies

    Science.gov (United States)

    Setia, Maninder Singh

    2016-01-01

    Once the research question and the research design have been finalised, it is important to select the appropriate sample for the study. The method by which the researcher selects the sample is the ‘ Sampling Method’. There are essentially two types of sampling methods: 1) probability sampling – based on chance events (such as random numbers, flipping a coin etc.); and 2) non-probability sampling – based on researcher's choice, population that accessible & available. Some of the non-probability sampling methods are: purposive sampling, convenience sampling, or quota sampling. Random sampling method (such as simple random sample or stratified random sample) is a form of probability sampling. It is important to understand the different sampling methods used in clinical studies and mention this method clearly in the manuscript. The researcher should not misrepresent the sampling method in the manuscript (such as using the term ‘ random sample’ when the researcher has used convenience sample). The sampling method will depend on the research question. For instance, the researcher may want to understand an issue in greater detail for one particular population rather than worry about the ‘ generalizability’ of these results. In such a scenario, the researcher may want to use ‘ purposive sampling’ for the study. PMID:27688438

  3. Graph Sampling for Covariance Estimation

    KAUST Repository

    Chepuri, Sundeep Prabhakar

    2017-04-25

    In this paper the focus is on subsampling as well as reconstructing the second-order statistics of signals residing on nodes of arbitrary undirected graphs. Second-order stationary graph signals may be obtained by graph filtering zero-mean white noise and they admit a well-defined power spectrum whose shape is determined by the frequency response of the graph filter. Estimating the graph power spectrum forms an important component of stationary graph signal processing and related inference tasks such as Wiener prediction or inpainting on graphs. The central result of this paper is that by sampling a significantly smaller subset of vertices and using simple least squares, we can reconstruct the second-order statistics of the graph signal from the subsampled observations, and more importantly, without any spectral priors. To this end, both a nonparametric approach as well as parametric approaches including moving average and autoregressive models for the graph power spectrum are considered. The results specialize for undirected circulant graphs in that the graph nodes leading to the best compression rates are given by the so-called minimal sparse rulers. A near-optimal greedy algorithm is developed to design the subsampling scheme for the non-parametric and the moving average models, whereas a particular subsampling scheme that allows linear estimation for the autoregressive model is proposed. Numerical experiments on synthetic as well as real datasets related to climatology and processing handwritten digits are provided to demonstrate the developed theory.

  4. Zamak samples analyses using EDXRF

    Energy Technology Data Exchange (ETDEWEB)

    Assis, J.T. de; Lima, I.; Monin, V., E-mail: joaquim@iprj.uerj.b, E-mail: inaya@iprj.uerj.b, E-mail: monin@iprj.uerj.b [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Inst. Politecnico. Dept. de Engenharia Mecanica e Energia; Anjos, M. dos; Lopes, R.T., E-mail: ricardo@lin.ufrj.b [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Alves, H., E-mail: marcelin@uerj.b, E-mail: haimon.dlafis@gmail.co [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada e Termodinamica

    2009-07-01

    Zamak is a family of alloys with a base metal of zinc and alloying elements of aluminium, magnesium and copper. Among all non-ferrous metal alloys, Zamak is one that has more applications, for their physical, mechanical properties and easy ability to electrodeposition. It has good resistance to corrosion, traction, shock and wear. Its low melting point (approximately 400 deg C) allows greater durability of the mold, allowing greater production of melted series parts. Zamak can be used in several kinds of areas, such as, to produce residential and industrial locks, construction and carpentry components, refrigerators hinges and so on. It is observed that in some cases the quality of these products is not very good. The problem should be the quality of Zamak alloy purchased by the industries. One possible technique that can be used to investigate the quality of these alloys is Energy Dispersive X-ray fluorescence. In this paper we present results of eight samples of Zamak alloy by this technique and it was possible to classify Zamak alloy and verify some irregularity on these alloys. (author)

  5. Marble Canyon spring sampling investigation

    International Nuclear Information System (INIS)

    McCulley, B.

    1985-10-01

    The Mississippian Leadville Limestone is the most permeable formation in the lower hydrostratigraphic unit underlying the salt beds of the Paradox Formation in Gibson Dome, Paradox Basin, Utah, which is being considered as a potential nuclear waste repository site. The closest downgradient outcrop of the Mississippian limestone is along the Colorado River in Marble Canyon, Arizona. This report describes the sampling and interpretation of springs in that area to assess the relative contribution of Gibson Dome-type Leadville Limestone ground water to that spring discharge. The high-volume (hundreds of liters per second or thousands of gallons per minute) springs discharging from fault zones in Marble Canyon are mixtures of water recharged west of the Colorado River on the Kaibab Plateau and east of the river in the Kaiparowits basin. No component of Gibson Dome-type Leadville Limestone ground water is evident in major and trace element chemistry or isotopic composition of the Marble Canyon Springs. A low-volume (0.3 liters per second or 5 gallons per minute) spring with some chemical and isotopic characteristics of Gibson Dome-type Leadville Limestone water diluted by Kaiparowits basin-type water issues from a travertine mound in the Bright Angel Shale on the Little Colorado River. However, the stable isotopic composition and bromide levels of that spring discharge, in addition to probable ground-water flow paths, contradict the dilution hypothesis

  6. Zamak samples analyses using EDXRF

    International Nuclear Information System (INIS)

    Assis, J.T. de; Lima, I.; Monin, V.; Anjos, M. dos; Lopes, R.T.; Alves, H.

    2009-01-01

    Zamak is a family of alloys with a base metal of zinc and alloying elements of aluminium, magnesium and copper. Among all non-ferrous metal alloys, Zamak is one that has more applications, for their physical, mechanical properties and easy ability to electrodeposition. It has good resistance to corrosion, traction, shock and wear. Its low melting point (approximately 400 deg C) allows greater durability of the mold, allowing greater production of melted series parts. Zamak can be used in several kinds of areas, such as, to produce residential and industrial locks, construction and carpentry components, refrigerators hinges and so on. It is observed that in some cases the quality of these products is not very good. The problem should be the quality of Zamak alloy purchased by the industries. One possible technique that can be used to investigate the quality of these alloys is Energy Dispersive X-ray fluorescence. In this paper we present results of eight samples of Zamak alloy by this technique and it was possible to classify Zamak alloy and verify some irregularity on these alloys. (author)

  7. Sample collection and sample analysis plan in support of the 105-C/190-C concrete and soil sampling activities

    International Nuclear Information System (INIS)

    Marske, S.G.

    1996-07-01

    This sampling and analysis plan describes the sample collection and sample analysis in support of the 105-C water tunnels and 190-C main pumphouse concrete and soil sampling activities. These analytical data will be used to identify the radiological contamination and presence of hazardous materials to support the decontamination and disposal activities

  8. 40 CFR 1065.245 - Sample flow meter for batch sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Sample flow meter for batch sampling... Sample flow meter for batch sampling. (a) Application. Use a sample flow meter to determine sample flow... difference between a diluted exhaust sample flow meter and a dilution air meter to calculate raw exhaust flow...

  9. Evaluation of respondent-driven sampling.

    Science.gov (United States)

    McCreesh, Nicky; Frost, Simon D W; Seeley, Janet; Katongole, Joseph; Tarsh, Matilda N; Ndunguse, Richard; Jichi, Fatima; Lunel, Natasha L; Maher, Dermot; Johnston, Lisa G; Sonnenberg, Pam; Copas, Andrew J; Hayes, Richard J; White, Richard G

    2012-01-01

    Respondent-driven sampling is a novel variant of link-tracing sampling for estimating the characteristics of hard-to-reach groups, such as HIV prevalence in sex workers. Despite its use by leading health organizations, the performance of this method in realistic situations is still largely unknown. We evaluated respondent-driven sampling by comparing estimates from a respondent-driven sampling survey with total population data. Total population data on age, tribe, religion, socioeconomic status, sexual activity, and HIV status were available on a population of 2402 male household heads from an open cohort in rural Uganda. A respondent-driven sampling (RDS) survey was carried out in this population, using current methods of sampling (RDS sample) and statistical inference (RDS estimates). Analyses were carried out for the full RDS sample and then repeated for the first 250 recruits (small sample). We recruited 927 household heads. Full and small RDS samples were largely representative of the total population, but both samples underrepresented men who were younger, of higher socioeconomic status, and with unknown sexual activity and HIV status. Respondent-driven sampling statistical inference methods failed to reduce these biases. Only 31%-37% (depending on method and sample size) of RDS estimates were closer to the true population proportions than the RDS sample proportions. Only 50%-74% of respondent-driven sampling bootstrap 95% confidence intervals included the population proportion. Respondent-driven sampling produced a generally representative sample of this well-connected nonhidden population. However, current respondent-driven sampling inference methods failed to reduce bias when it occurred. Whether the data required to remove bias and measure precision can be collected in a respondent-driven sampling survey is unresolved. Respondent-driven sampling should be regarded as a (potentially superior) form of convenience sampling method, and caution is required

  10. Evaluation of Respondent-Driven Sampling

    Science.gov (United States)

    McCreesh, Nicky; Frost, Simon; Seeley, Janet; Katongole, Joseph; Tarsh, Matilda Ndagire; Ndunguse, Richard; Jichi, Fatima; Lunel, Natasha L; Maher, Dermot; Johnston, Lisa G; Sonnenberg, Pam; Copas, Andrew J; Hayes, Richard J; White, Richard G

    2012-01-01

    Background Respondent-driven sampling is a novel variant of link-tracing sampling for estimating the characteristics of hard-to-reach groups, such as HIV prevalence in sex-workers. Despite its use by leading health organizations, the performance of this method in realistic situations is still largely unknown. We evaluated respondent-driven sampling by comparing estimates from a respondent-driven sampling survey with total-population data. Methods Total-population data on age, tribe, religion, socioeconomic status, sexual activity and HIV status were available on a population of 2402 male household-heads from an open cohort in rural Uganda. A respondent-driven sampling (RDS) survey was carried out in this population, employing current methods of sampling (RDS sample) and statistical inference (RDS estimates). Analyses were carried out for the full RDS sample and then repeated for the first 250 recruits (small sample). Results We recruited 927 household-heads. Full and small RDS samples were largely representative of the total population, but both samples under-represented men who were younger, of higher socioeconomic status, and with unknown sexual activity and HIV status. Respondent-driven-sampling statistical-inference methods failed to reduce these biases. Only 31%-37% (depending on method and sample size) of RDS estimates were closer to the true population proportions than the RDS sample proportions. Only 50%-74% of respondent-driven-sampling bootstrap 95% confidence intervals included the population proportion. Conclusions Respondent-driven sampling produced a generally representative sample of this well-connected non-hidden population. However, current respondent-driven-sampling inference methods failed to reduce bias when it occurred. Whether the data required to remove bias and measure precision can be collected in a respondent-driven sampling survey is unresolved. Respondent-driven sampling should be regarded as a (potentially superior) form of convenience-sampling

  11. Spot sputum samples are at least as good as early morning samples for identifying Mycobacterium tuberculosis.

    Science.gov (United States)

    Murphy, Michael E; Phillips, Patrick P J; Mendel, Carl M; Bongard, Emily; Bateson, Anna L C; Hunt, Robert; Murthy, Saraswathi; Singh, Kasha P; Brown, Michael; Crook, Angela M; Nunn, Andrew J; Meredith, Sarah K; Lipman, Marc; McHugh, Timothy D; Gillespie, Stephen H

    2017-10-27

    The use of early morning sputum samples (EMS) to diagnose tuberculosis (TB) can result in treatment delay given the need for the patient to return to the clinic with the EMS, increasing the chance of patients being lost during their diagnostic workup. However, there is little evidence to support the superiority of EMS over spot sputum samples. In this new analysis of the REMoxTB study, we compare the diagnostic accuracy of EMS with spot samples for identifying Mycobacterium tuberculosis pre- and post-treatment. Patients who were smear positive at screening were enrolled into the study. Paired sputum samples (one EMS and one spot) were collected at each trial visit pre- and post-treatment. Microscopy and culture on solid LJ and liquid MGIT media were performed on all samples; those missing corresponding paired results were excluded from the analyses. Data from 1115 pre- and 2995 post-treatment paired samples from 1931 patients enrolled in the REMoxTB study were analysed. Patients were recruited from South Africa (47%), East Africa (21%), India (20%), Asia (11%), and North America (1%); 70% were male, median age 31 years (IQR 24-41), 139 (7%) co-infected with HIV with a median CD4 cell count of 399 cells/μL (IQR 318-535). Pre-treatment spot samples had a higher yield of positive Ziehl-Neelsen smears (98% vs. 97%, P = 0.02) and LJ cultures (87% vs. 82%, P = 0.006) than EMS, but there was no difference for positivity by MGIT (93% vs. 95%, P = 0.18). Contaminated and false-positive MGIT were found more often with EMS rather than spot samples. Surprisingly, pre-treatment EMS had a higher smear grading and shorter time-to-positivity, by 1 day, than spot samples in MGIT culture (4.5 vs. 5.5 days, P spot samples in those with unfavourable outcomes, there were no differences in smear or culture results, and positive results were not detected earlier in Kaplan-Meier analyses in either EMS or spot samples. Our data do not support the hypothesis that EMS

  12. Impact of neurosurgeon specialization on patient outcomes for intracranial and spinal surgery: a retrospective analysis of the Nationwide Inpatient Sample 1998-2009.

    Science.gov (United States)

    McCutcheon, Brandon A; Hirshman, Brian R; Gabel, Brandon C; Heffner, Michael W; Marcus, Logan P; Cole, Tyler S; Chen, Clark C; Chang, David C; Carter, Bob S

    2018-05-01

    OBJECTIVE The subspecialization of neurosurgical practice is an ongoing trend in modern neurosurgery. However, it remains unclear whether the degree of surgeon specialization is associated with improved patient outcomes. The authors hypothesized that a trend toward increased neurosurgeon specialization was associated with improved patient morbidity and mortality rates. METHODS The Nationwide Inpatient Sample (NIS) was used (1998-2009). Patients were included in a spinal analysis cohort for instrumented spine surgery involving the cervical spine ( International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes 81.31-81.33, 81.01-81.03, 84.61-84.62, and 84.66) or lumbar spine (codes 81.04-81.08, 81.34-81.38, 84.64-84.65, and 84.68). A cranial analysis cohort consisted of patients receiving a parenchymal excision or lobectomy operation (codes 01.53 and 01.59). Surgeon specialization was measured using unique surgeon identifiers in the NIS and defined as the proportion of a surgeon's total practice dedicated to cranial or spinal cases. RESULTS A total of 46,029 and 231,875 patients were identified in the cranial and spinal analysis cohorts, respectively. On multivariate analysis in the cranial analysis cohort (after controlling for overall surgeon volume, patient demographic data/comorbidities, hospital characteristics, and admitting source), each percentage-point increase in a surgeon's cranial specialization (that is, the proportion of cranial cases) was associated with a 0.0060 reduction in the log odds of patient mortality (95% CI 0.0034-0.0086) and a 0.0042 reduction in the log odds of morbidity (95% CI 0.0032-0.0052). This resulted in a 15% difference in the predicted probability of mortality for neurosurgeons at the 75th versus the 25th percentile of cranial specialization. In the spinal analysis cohort, each percentage-point increase in a surgeon's spinal specialization was associated with a 0.0122 reduction in the log odds of

  13. 40 CFR 761.323 - Sample preparation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sample preparation. 761.323 Section... Remediation Waste Samples § 761.323 Sample preparation. (a) The comparison study requires analysis of a... concentrations by dilution. Any excess material resulting from the preparation of these samples, which is not...

  14. Tank 12H residuals sample analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shine, E. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Diprete, D. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coleman, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hay, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-06-11

    The Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) to provide sample preparation and analysis of the Tank 12H final characterization samples to determine the residual tank inventory prior to grouting. Eleven Tank 12H floor and mound residual material samples and three cooling coil scrape samples were collected and delivered to SRNL between May and August of 2014.

  15. Device for sampling HTGR recycle fuel particles

    International Nuclear Information System (INIS)

    Suchomel, R.R.; Lackey, W.J.

    1977-03-01

    Devices for sampling High-Temperature Gas-Cooled Reactor fuel microspheres were evaluated. Analysis of samples obtained with each of two specially designed passive samplers were compared with data generated by more common techniques. A ten-stage two-way sampler was found to produce a representative sample with a constant batch-to-sample ratio

  16. Core sampling system spare parts assessment

    International Nuclear Information System (INIS)

    Walter, E.J.

    1995-01-01

    Soon, there will be 4 independent core sampling systems obtaining samples from the underground tanks. It is desirable that these systems be available for sampling during the next 2 years. This assessment was prepared to evaluate the adequacy of the spare parts identified for the core sampling system and to provide recommendations that may remediate overages or inadequacies of spare parts

  17. 40 CFR 141.702 - Sampling schedules.

    Science.gov (United States)

    2010-07-01

    ... serving at least 10,000 people must submit their sampling schedule for the initial round of source water... submitting the sampling schedule that EPA approves. (3) Systems serving fewer than 10,000 people must submit... analytical result for a scheduled sampling date due to equipment failure, loss of or damage to the sample...

  18. Special nuclear material inventory sampling plans

    International Nuclear Information System (INIS)

    Vaccaro, H.S.; Goldman, A.S.

    1987-01-01

    This paper presents improved procedures for obtaining statistically valid sampling plans for nuclear facilities. The double sampling concept and methods for developing optimal double sampling plans are described. An algorithm is described that is satisfactory for finding optimal double sampling plans and choosing appropriate detection and false alarm probabilities

  19. 30 CFR 90.208 - Bimonthly sampling.

    Science.gov (United States)

    2010-07-01

    ... MANDATORY HEALTH STANDARDS-COAL MINERS WHO HAVE EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.208 Bimonthly sampling. (a) Each operator shall take one valid respirable dust sample for... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bimonthly sampling. 90.208 Section 90.208...

  20. 30 CFR 90.207 - Compliance sampling.

    Science.gov (United States)

    2010-07-01

    ... MANDATORY HEALTH STANDARDS-COAL MINERS WHO HAVE EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.207 Compliance sampling. (a) The operator shall take five valid respirable dust samples for... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compliance sampling. 90.207 Section 90.207...

  1. 7 CFR 51.17 - Official sampling.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Official sampling. 51.17 Section 51.17 Agriculture... Inspection Service § 51.17 Official sampling. Samples may be officially drawn by any duly authorized... time and place of the sampling and the brands or other identifying marks of the containers from which...

  2. Sampling wild species to conserve genetic diversity

    Science.gov (United States)

    Sampling seed from natural populations of crop wild relatives requires choice of the locations to sample from and the amount of seed to sample. While this may seem like a simple choice, in fact careful planning of a collector’s sampling strategy is needed to ensure that a crop wild collection will ...

  3. 40 CFR 61.34 - Air sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Air sampling. 61.34 Section 61.34... sampling. (a) Stationary sources subject to § 61.32(b) shall locate air sampling sites in accordance with a... concentrations calculated within 30 days after filters are collected. Records of concentrations at all sampling...

  4. 45 CFR 1356.84 - Sampling.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Sampling. 1356.84 Section 1356.84 Public Welfare....84 Sampling. (a) The State agency may collect and report the information required in section 1356.83(e) of this part on a sample of the baseline population consistent with the sampling requirements...

  5. Comparison of sampling methods for animal manure

    NARCIS (Netherlands)

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

    1997-01-01

    Currently available and recently developed sampling methods for slurry and solid manure were tested for bias and reproducibility in the determination of total phosphorus and nitrogen content of samples. Sampling methods were based on techniques in which samples were taken either during loading from

  6. Credit in Acceptance Sampling on Attributes

    NARCIS (Netherlands)

    Klaassen, Chris A.J.

    2000-01-01

    Credit is introduced in acceptance sampling on attributes and a Credit Based Acceptance sampling system is developed that is very easy to apply in practice.The credit of a producer is defined as the total number of items accepted since the last rejection.In our sampling system the sample size for a

  7. Sample container for neutron activation analysis

    International Nuclear Information System (INIS)

    Lersmacher, B.; Verheijke, M.L.; Jaspers, H.J.

    1983-01-01

    The sample container avoids contaminating the sample substance by diffusion of foreign matter from the wall of the sample container into the sample. It cannot be activated, so that the results of measurements are not falsified by a radioactive container wall. It consists of solid carbon. (orig./HP) [de

  8. Nested Sampling with Constrained Hamiltonian Monte Carlo

    OpenAIRE

    Betancourt, M. J.

    2010-01-01

    Nested sampling is a powerful approach to Bayesian inference ultimately limited by the computationally demanding task of sampling from a heavily constrained probability distribution. An effective algorithm in its own right, Hamiltonian Monte Carlo is readily adapted to efficiently sample from any smooth, constrained distribution. Utilizing this constrained Hamiltonian Monte Carlo, I introduce a general implementation of the nested sampling algorithm.

  9. Computer Graphics Simulations of Sampling Distributions.

    Science.gov (United States)

    Gordon, Florence S.; Gordon, Sheldon P.

    1989-01-01

    Describes the use of computer graphics simulations to enhance student understanding of sampling distributions that arise in introductory statistics. Highlights include the distribution of sample proportions, the distribution of the difference of sample means, the distribution of the difference of sample proportions, and the distribution of sample…

  10. Physical sampling for site and waste characterization

    International Nuclear Information System (INIS)

    Bonnough, T.L.

    1994-01-01

    Physical sampling plays a basic role in site and waste characterization program effort. The term ''physical sampling'' used here means collecting tangible, physical samples of soil, water, air, waste streams, or other materials. The industry defines the term ''physical sampling'' broadly to include measurements of physical conditions such as temperature, wind conditions, and pH which are also often taken in a sample collection effort. Most environmental compliance actions are supported by the results of taking, recording, and analyzing physical samples and the measuring of physical conditions taken in association with sample collecting

  11. Soil sampling strategies: Evaluation of different approaches

    International Nuclear Information System (INIS)

    De Zorzi, Paolo; Barbizzi, Sabrina; Belli, Maria; Mufato, Renzo; Sartori, Giuseppe; Stocchero, Giulia

    2008-01-01

    The National Environmental Protection Agency of Italy (APAT) performed a soil sampling intercomparison, inviting 14 regional agencies to test their own soil sampling strategies. The intercomparison was carried out at a reference site, previously characterised for metal mass fraction distribution. A wide range of sampling strategies, in terms of sampling patterns, type and number of samples collected, were used to assess the mean mass fraction values of some selected elements. The different strategies led in general to acceptable bias values (D) less than 2σ, calculated according to ISO 13258. Sampling on arable land was relatively easy, with comparable results between different sampling strategies

  12. Soil sampling strategies: Evaluation of different approaches

    Energy Technology Data Exchange (ETDEWEB)

    De Zorzi, Paolo [Agenzia per la Protezione dell' Ambiente e per i Servizi Tecnici (APAT), Servizio Metrologia Ambientale, Via di Castel Romano, 100-00128 Roma (Italy)], E-mail: paolo.dezorzi@apat.it; Barbizzi, Sabrina; Belli, Maria [Agenzia per la Protezione dell' Ambiente e per i Servizi Tecnici (APAT), Servizio Metrologia Ambientale, Via di Castel Romano, 100-00128 Roma (Italy); Mufato, Renzo; Sartori, Giuseppe; Stocchero, Giulia [Agenzia Regionale per la Prevenzione e Protezione dell' Ambiente del Veneto, ARPA Veneto, U.O. Centro Qualita Dati, Via Spalato, 14-36045 Vicenza (Italy)

    2008-11-15

    The National Environmental Protection Agency of Italy (APAT) performed a soil sampling intercomparison, inviting 14 regional agencies to test their own soil sampling strategies. The intercomparison was carried out at a reference site, previously characterised for metal mass fraction distribution. A wide range of sampling strategies, in terms of sampling patterns, type and number of samples collected, were used to assess the mean mass fraction values of some selected elements. The different strategies led in general to acceptable bias values (D) less than 2{sigma}, calculated according to ISO 13258. Sampling on arable land was relatively easy, with comparable results between different sampling strategies.

  13. Soil sampling strategies: evaluation of different approaches.

    Science.gov (United States)

    de Zorzi, Paolo; Barbizzi, Sabrina; Belli, Maria; Mufato, Renzo; Sartori, Giuseppe; Stocchero, Giulia

    2008-11-01

    The National Environmental Protection Agency of Italy (APAT) performed a soil sampling intercomparison, inviting 14 regional agencies to test their own soil sampling strategies. The intercomparison was carried out at a reference site, previously characterised for metal mass fraction distribution. A wide range of sampling strategies, in terms of sampling patterns, type and number of samples collected, were used to assess the mean mass fraction values of some selected elements. The different strategies led in general to acceptable bias values (D) less than 2sigma, calculated according to ISO 13258. Sampling on arable land was relatively easy, with comparable results between different sampling strategies.

  14. An improved sampling method of complex network

    Science.gov (United States)

    Gao, Qi; Ding, Xintong; Pan, Feng; Li, Weixing

    2014-12-01

    Sampling subnet is an important topic of complex network research. Sampling methods influence the structure and characteristics of subnet. Random multiple snowball with Cohen (RMSC) process sampling which combines the advantages of random sampling and snowball sampling is proposed in this paper. It has the ability to explore global information and discover the local structure at the same time. The experiments indicate that this novel sampling method could keep the similarity between sampling subnet and original network on degree distribution, connectivity rate and average shortest path. This method is applicable to the situation where the prior knowledge about degree distribution of original network is not sufficient.

  15. Apparatus for sectioning demountable semiconductor samples

    Science.gov (United States)

    Sopori, B.L.; Wolf, A.

    1984-01-01

    Apparatus for use during polishing and sectioning operations of a ribbon sample is described. The sample holder includes a cylinder having an axially extending sample cavity terminated in a first funnel-shaped opening and a second slot-like opening. A spring-loaded pressure plunger is located adjacent the second opening of the sample cavity for frictional engagement of the sample cavity. A heat softenable molding medium is inserted in the funnel-shaped opening, to surround the sample. After polishing, the heater is energized to allow draining of the molding medium from the sample cavity. During manual polishing, the second end of the sample holder is inserted in a support ring which provides mechanical support as well as alignment of the sample holder during polishing. A gauge block for measuring the protrusion of a sample beyond the second wall of the holder is also disclosed.

  16. MaxEnt queries and sequential sampling

    International Nuclear Information System (INIS)

    Riegler, Peter; Caticha, Nestor

    2001-01-01

    In this paper we pose the question: After gathering N data points, at what value of the control parameter should the next measurement be done? We propose an on-line algorithm which samples optimally by maximizing the gain in information on the parameters to be measured. We show analytically that the information gain is maximum for those potential measurements whose outcome is most unpredictable, i.e. for which the predictive distribution has maximum entropy. The resulting algorithm is applied to exponential analysis

  17. Sampling Large Graphs for Anticipatory Analytics

    Science.gov (United States)

    2015-05-15

    low. C. Random Area Sampling Random area sampling [8] is a “ snowball ” sampling method in which a set of random seed vertices are selected and areas... Sampling Large Graphs for Anticipatory Analytics Lauren Edwards, Luke Johnson, Maja Milosavljevic, Vijay Gadepally, Benjamin A. Miller Lincoln...systems, greater human-in-the-loop involvement, or through complex algorithms. We are investigating the use of sampling to mitigate these challenges

  18. A Bayesian Method for Weighted Sampling

    OpenAIRE

    Lo, Albert Y.

    1993-01-01

    Bayesian statistical inference for sampling from weighted distribution models is studied. Small-sample Bayesian bootstrap clone (BBC) approximations to the posterior distribution are discussed. A second-order property for the BBC in unweighted i.i.d. sampling is given. A consequence is that BBC approximations to a posterior distribution of the mean and to the sampling distribution of the sample average, can be made asymptotically accurate by a proper choice of the random variables that genera...

  19. Determination of tritium in wine yeast samples

    International Nuclear Information System (INIS)

    Cotarlea, Monica-Ionela; Paunescu Niculina; Galeriu, D; Mocanu, N.; Margineanu, R.; Marin, G.

    1998-01-01

    Analytical procedures were developed to determine tritium in wine and wine yeast samples. The content of organic compounds affecting the LSC measurement is reduced by fractioning distillation for wine samples and azeotropic distillation/fractional distillation for wine yeast samples. Finally, the water samples were normally distilled with K MO 4 . The established procedures were successfully applied for wine and wine samples from Murfatlar harvests of the years 1995 and 1996. (authors)

  20. Optimal sampling designs for large-scale fishery sample surveys in Greece

    Directory of Open Access Journals (Sweden)

    G. BAZIGOS

    2007-12-01

    The paper deals with the optimization of the following three large scale sample surveys: biological sample survey of commercial landings (BSCL, experimental fishing sample survey (EFSS, and commercial landings and effort sample survey (CLES.

  1. Sampling method of environmental radioactivity monitoring

    International Nuclear Information System (INIS)

    1984-01-01

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

  2. Sample vial inserts: A better approach for sampling heterogeneous slurry samples in the SRS Defense Waste Processing Facility

    International Nuclear Information System (INIS)

    Coleman, C.J.; Goode, S.R.

    1996-01-01

    A convenient and effective new approach for analyzing DWPF samples involves the use of inserts with volumes of 1.5--3 ml placed in the neck of 14 ml sample vials. The inserts have rims that conform to the rim of the vials so that they sit straight and stable in the vial. The DWPF tank sampling system fills the pre-weighed insert rather than the entire vial, so the vial functions only as the insert holder. The shielded cell operator then removes the vial cap and decants the insert containing the sample into a plastic bottle, crucible, etc., for analysis. Inert materials such as Teflon, plastic, and zirconium are used for the insert so it is unnecessary to separate the insert from the sample for most analyses. The key technique advantage of using inserts to take DWPF samples versus filling sample vials is that it provides a convenient and almost foolproof way of obtaining and handling small volumes of slurry samples in a shielded cell without corrupting the sample. Since the insert allows the entire sample to be analyzed, this approach eliminates the errors inherent with subsampling heterogeneous slurries that comprise DWPF samples. Slurry samples can then be analyzed with confidence. Analysis times are dramatically reduced by eliminating the drying and vitrification steps normally used to produce a homogeneous solid sample. Direct dissolution and elemental analysis of slurry samples are achieved in 8 hours or less compared with 40 hours for analysis of vitrified slurry samples. Comparison of samples taken in inserts versus full vials indicate that the insert does not significantly affect sample composition

  3. 21 CFR 203.38 - Sample lot or control numbers; labeling of sample units.

    Science.gov (United States)

    2010-04-01

    ... numbers; labeling of sample units. (a) Lot or control number required on drug sample labeling and sample... identifying lot or control number that will permit the tracking of the distribution of each drug sample unit... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Sample lot or control numbers; labeling of sample...

  4. Sample selection may bias the outcome of an adolescent mental health survey: results from a five-year follow-up of 4171 adolescents.

    Science.gov (United States)

    Kekkonen, V; Kivimäki, P; Valtonen, H; Hintikka, J; Tolmunen, T; Lehto, S M; Laukkanen, E

    2015-02-01

    The representativeness of the data is one of the main issues in evaluating the significance of research findings. Dropping out is common in adolescent mental health research, and may distort the results. Nevertheless, very little is known about the types of systematic bias that may affect studies in a) the informed consent phase and b) later in follow-up phases. The authors addressed this gap in knowledge in a five-year follow-up study on a sample of adolescents aged 13-18 years. The data were collected using self-report questionnaires. The baseline sample consisted of 4171 adolescents, 1827 (43.8%) of whom gave consent to be contacted for a follow-up survey, but only 797 (19.1%) participated in the follow-up. Binary logistic regression models were used to explain the participation. Young age, female gender, a high number of hobbies, good performance at school in the native language and general subjects, family disintegration such as divorce, high parental employment, and symptoms of depression and anxiety were associated with both consent and participation. However, the effect of mental health aspects was smaller than the effect of age and gender. This study confirmed the possibility of systematic selection bias by adolescents' sociodemographic characteristics. The representativeness of the study sample might have been improved by more intense recruitment strategies. Copyright © 2014 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  5. FUZZY ACCEPTANCE SAMPLING AND CHARACTERISTIC CURVES

    Directory of Open Access Journals (Sweden)

    Ebru Turano?lu

    2012-02-01

    Full Text Available Acceptance sampling is primarily used for the inspection of incoming or outgoing lots. Acceptance sampling refers to the application of specific sampling plans to a designated lot or sequence of lots. The parameters of acceptance sampling plans are sample sizes and acceptance numbers. In some cases, it may not be possible to define acceptance sampling parameters as crisp values. These parameters can be expressed by linguistic variables. The fuzzy set theory can be successfully used to cope with the vagueness in these linguistic expressions for acceptance sampling. In this paper, the main distributions of acceptance sampling plans are handled with fuzzy parameters and their acceptance probability functions are derived. Then the characteristic curves of acceptance sampling are examined under fuzziness. Illustrative examples are given.

  6. Multiple sample, radioactive particle counting apparatus

    International Nuclear Information System (INIS)

    Reddy, R.R.V.; Kelso, D.M.

    1978-01-01

    An apparatus is described for determining the respective radioactive particle sample count being emitted from radioactive particle containing samples. It includes means for modulating the information on the radioactive particles being emitted from the samples, coded detecting means for sequentially detecting different respective coded combinations of the radioactive particles emitted from more than one but less than all of the samples, and processing the modulated information to derive the sample count for each sample. It includes a single light emitting crystal next to a number of samples, an encoder belt sequentially movable between the crystal and the samples. The encoder belt has a coded array of apertures to provide corresponding modulated light pulses from the crystal, and a photomultiplier tube to convert the modulated light pulses to decodable electrical signals for deriving the respective sample count

  7. Systematic versus random sampling in stereological studies.

    Science.gov (United States)

    West, Mark J

    2012-12-01

    The sampling that takes place at all levels of an experimental design must be random if the estimate is to be unbiased in a statistical sense. There are two fundamental ways by which one can make a random sample of the sections and positions to be probed on the sections. Using a card-sampling analogy, one can pick any card at all out of a deck of cards. This is referred to as independent random sampling because the sampling of any one card is made without reference to the position of the other cards. The other approach to obtaining a random sample would be to pick a card within a set number of cards and others at equal intervals within the deck. Systematic sampling along one axis of many biological structures is more efficient than random sampling, because most biological structures are not randomly organized. This article discusses the merits of systematic versus random sampling in stereological studies.

  8. Special nuclear material inventory sampling plans

    International Nuclear Information System (INIS)

    Vaccaro, H.; Goldman, A.

    1987-01-01

    Since their introduction in 1942, sampling inspection procedures have been common quality assurance practice. The U.S. Department of Energy (DOE) supports such sampling of special nuclear materials inventories. The DOE Order 5630.7 states, Operations Offices may develop and use statistically valid sampling plans appropriate for their site-specific needs. The benefits for nuclear facilities operations include reduced worker exposure and reduced work load. Improved procedures have been developed for obtaining statistically valid sampling plans that maximize these benefits. The double sampling concept is described and the resulting sample sizes for double sample plans are compared with other plans. An algorithm is given for finding optimal double sampling plans that assist in choosing the appropriate detection and false alarm probabilities for various sampling plans

  9. Verification of Representative Sampling in RI waste

    International Nuclear Information System (INIS)

    Ahn, Hong Joo; Song, Byung Cheul; Sohn, Se Cheul; Song, Kyu Seok; Jee, Kwang Yong; Choi, Kwang Seop

    2009-01-01

    For evaluating the radionuclide inventories for RI wastes, representative sampling is one of the most important parts in the process of radiochemical assay. Sampling to characterized RI waste conditions typically has been based on judgment or convenience sampling of individual or groups. However, it is difficult to get a sample representatively among the numerous drums. In addition, RI waste drums might be classified into heterogeneous wastes because they have a content of cotton, glass, vinyl, gloves, etc. In order to get the representative samples, the sample to be analyzed must be collected from selected every drum. Considering the expense and time of analysis, however, the number of sample has to be minimized. In this study, RI waste drums were classified by the various conditions of the half-life, surface dose, acceptance date, waste form, generator, etc. A sample for radiochemical assay was obtained through mixing samples of each drum. The sample has to be prepared for radiochemical assay and although the sample should be reasonably uniform, it is rare that a completely homogeneous material is received. Every sample is shredded by a 1 ∼ 2 cm 2 diameter and a representative aliquot taken for the required analysis. For verification of representative sampling, classified every group is tested for evaluation of 'selection of representative drum in a group' and 'representative sampling in a drum'

  10. Rational learning and information sampling: on the "naivety" assumption in sampling explanations of judgment biases.

    Science.gov (United States)

    Le Mens, Gaël; Denrell, Jerker

    2011-04-01

    Recent research has argued that several well-known judgment biases may be due to biases in the available information sample rather than to biased information processing. Most of these sample-based explanations assume that decision makers are "naive": They are not aware of the biases in the available information sample and do not correct for them. Here, we show that this "naivety" assumption is not necessary. Systematically biased judgments can emerge even when decision makers process available information perfectly and are also aware of how the information sample has been generated. Specifically, we develop a rational analysis of Denrell's (2005) experience sampling model, and we prove that when information search is interested rather than disinterested, even rational information sampling and processing can give rise to systematic patterns of errors in judgments. Our results illustrate that a tendency to favor alternatives for which outcome information is more accessible can be consistent with rational behavior. The model offers a rational explanation for behaviors that had previously been attributed to cognitive and motivational biases, such as the in-group bias or the tendency to prefer popular alternatives. 2011 APA, all rights reserved

  11. The optimal sampling of outsourcing product

    International Nuclear Information System (INIS)

    Yang Chao; Pei Jiacheng

    2014-01-01

    In order to improve quality and cost, the sampling c = 0 has been introduced to the inspection of outsourcing product. According to the current quality level (p = 0.4%), we confirmed the optimal sampling that is: Ac = 0; if N ≤ 3000, n = 55; 3001 ≤ N ≤ 10000, n = 86; N ≥ 10001, n = 108. Through analyzing the OC curve, we came to the conclusion that when N ≤ 3000, the protective ability of optimal sampling for product quality is stronger than current sampling. Corresponding to the same 'consumer risk', the product quality of optimal sampling is superior to current sampling. (authors)

  12. Sampling a guide for internal auditors

    CERN Document Server

    Apostolou, Barbara

    2004-01-01

    While it is possible to examine 100 percent of an audit customer's data, the time and cost associated with such a study are often prohibitive. To obtain sufficient, reliable, and relevant information with a limited data set, sampling is an efficient and effective tool. It can help you evaluate the customer's assertions, as well as reach audit conclusions and provide reasonable assurance to your organization. This handbook will help you understand sampling. It also serves as a guide for auditors and students preparing for certification. Topics include: An overview of sampling. Statistical and nonstatistical sampling issues. Sampling selection methods and risks. The pros and cons of popular sampling plans.

  13. ALARA ASSESSMENT OF SETTLER SLUDGE SAMPLING METHODS

    International Nuclear Information System (INIS)

    Nelsen, L.A.

    2009-01-01

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

  14. ALARA ASSESSMENT OF SETTLER SLUDGE SAMPLING METHODS

    Energy Technology Data Exchange (ETDEWEB)

    NELSEN LA

    2009-01-30

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

  15. Small sample whole-genome amplification

    Science.gov (United States)

    Hara, Christine; Nguyen, Christine; Wheeler, Elizabeth; Sorensen, Karen; Arroyo, Erin; Vrankovich, Greg; Christian, Allen

    2005-11-01

    Many challenges arise when trying to amplify and analyze human samples collected in the field due to limitations in sample quantity, and contamination of the starting material. Tests such as DNA fingerprinting and mitochondrial typing require a certain sample size and are carried out in large volume reactions; in cases where insufficient sample is present whole genome amplification (WGA) can be used. WGA allows very small quantities of DNA to be amplified in a way that enables subsequent DNA-based tests to be performed. A limiting step to WGA is sample preparation. To minimize the necessary sample size, we have developed two modifications of WGA: the first allows for an increase in amplified product from small, nanoscale, purified samples with the use of carrier DNA while the second is a single-step method for cleaning and amplifying samples all in one column. Conventional DNA cleanup involves binding the DNA to silica, washing away impurities, and then releasing the DNA for subsequent testing. We have eliminated losses associated with incomplete sample release, thereby decreasing the required amount of starting template for DNA testing. Both techniques address the limitations of sample size by providing ample copies of genomic samples. Carrier DNA, included in our WGA reactions, can be used when amplifying samples with the standard purification method, or can be used in conjunction with our single-step DNA purification technique to potentially further decrease the amount of starting sample necessary for future forensic DNA-based assays.

  16. Toward cost-efficient sampling methods

    Science.gov (United States)

    Luo, Peng; Li, Yongli; Wu, Chong; Zhang, Guijie

    2015-09-01

    The sampling method has been paid much attention in the field of complex network in general and statistical physics in particular. This paper proposes two new sampling methods based on the idea that a small part of vertices with high node degree could possess the most structure information of a complex network. The two proposed sampling methods are efficient in sampling high degree nodes so that they would be useful even if the sampling rate is low, which means cost-efficient. The first new sampling method is developed on the basis of the widely used stratified random sampling (SRS) method and the second one improves the famous snowball sampling (SBS) method. In order to demonstrate the validity and accuracy of two new sampling methods, we compare them with the existing sampling methods in three commonly used simulation networks that are scale-free network, random network, small-world network, and also in two real networks. The experimental results illustrate that the two proposed sampling methods perform much better than the existing sampling methods in terms of achieving the true network structure characteristics reflected by clustering coefficient, Bonacich centrality and average path length, especially when the sampling rate is low.

  17. ISCO Grab Sample Ion Chromatography Analytical Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — ISCO grab samples were collected from river, wastewater treatment plant discharge, and public drinking water intakes. Samples were analyzed for major ions (ppb)...

  18. Aerobot Sampling and Handling System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Honeybee Robotics proposes to: ?Derive and document the functional and technical requirements for Aerobot surface sampling and sample handling across a range of...

  19. Paleomagnetic Studies of Returned Samples from Mars

    Science.gov (United States)

    Weiss, B. P.; Beaty, D. W.; McSween, H. Y.; Carrier, B. L.; Czaja, A. D.; Goreva, Y. S.; Hausrath, E.; Herd, C. D. K.; Humayun, M.; McCubbin, F. M.; McLennan, S. M.; Pratt, L. M.; Sephton, M. A.; Steele, A.

    2018-04-01

    Magnetic measurements of returned samples could transform our understanding of the martian dynamo and its connection to climatic and planetary thermal evolution and provide powerful constraints on the preservation state of sample biosignatures.

  20. 40 CFR 89.507 - Sample selection.

    Science.gov (United States)

    2010-07-01

    ... Auditing § 89.507 Sample selection. (a) Engines comprising a test sample will be selected at the location...). However, once the manufacturer ships any test engine, it relinquishes the prerogative to conduct retests...

  1. 40 CFR 90.507 - Sample selection.

    Science.gov (United States)

    2010-07-01

    ... Auditing § 90.507 Sample selection. (a) Engines comprising a test sample will be selected at the location... manufacturer ships any test engine, it relinquishes the prerogative to conduct retests as provided in § 90.508...

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

    OpenAIRE

    Grafström, Anton

    2005-01-01

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

  3. Sampling the Mouse Hippocampal Dentate Gyrus

    OpenAIRE

    Lisa Basler; Lisa Basler; Stephan Gerdes; David P. Wolfer; David P. Wolfer; David P. Wolfer; Lutz Slomianka; Lutz Slomianka

    2017-01-01

    Sampling is a critical step in procedures that generate quantitative morphological data in the neurosciences. Samples need to be representative to allow statistical evaluations, and samples need to deliver a precision that makes statistical evaluations not only possible but also meaningful. Sampling generated variability should, e.g., not be able to hide significant group differences from statistical detection if they are present. Estimators of the coefficient of error (CE) have been develope...

  4. Equilibrium Molecular Thermodynamics from Kirkwood Sampling

    OpenAIRE

    Somani, Sandeep; Okamoto, Yuko; Ballard, Andrew J.; Wales, David J.

    2015-01-01

    We present two methods for barrierless equilibrium sampling of molecular systems based on the recently proposed Kirkwood method (J. Chem. Phys. 2009, 130, 134102). Kirkwood sampling employs low-order correlations among internal coordinates of a molecule for random (or non-Markovian) sampling of the high dimensional conformational space. This is a geometrical sampling method independent of the potential energy surface. The first method is a variant of biased Monte Carlo, wher...

  5. Sampling marine sediments for radionuclide monitoring

    International Nuclear Information System (INIS)

    Papucci, C.

    1997-01-01

    A description of the most common devices used for sampling marine sediments are reported. The systems are compared to evidence their intrinsic usefulness, for collecting samples in different environmental conditions or with different scientific objectives. Perturbations and artifacts introduced during the various steps of the sampling procedure are also reviewed, and suggestions are proposed for obtaining and preserving, as much as possible, the representativeness of the sediment samples. (author)

  6. 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...

  7. Commutability of food microbiology proficiency testing samples.

    Science.gov (United States)

    Abdelmassih, M; Polet, M; Goffaux, M-J; Planchon, V; Dierick, K; Mahillon, J

    2014-03-01

    Food microbiology proficiency testing (PT) is a useful tool to assess the analytical performances among laboratories. PT items should be close to routine samples to accurately evaluate the acceptability of the methods. However, most PT providers distribute exclusively artificial samples such as reference materials or irradiated foods. This raises the issue of the suitability of these samples because the equivalence-or 'commutability'-between results obtained on artificial vs. authentic food samples has not been demonstrated. In the clinical field, the use of noncommutable PT samples has led to erroneous evaluation of the performances when different analytical methods were used. This study aimed to provide a first assessment of the commutability of samples distributed in food microbiology PT. REQUASUD and IPH organized 13 food microbiology PTs including 10-28 participants. Three types of PT items were used: genuine food samples, sterile food samples and reference materials. The commutability of the artificial samples (reference material or sterile samples) was assessed by plotting the distribution of the results on natural and artificial PT samples. This comparison highlighted matrix-correlated issues when nonfood matrices, such as reference materials, were used. Artificially inoculated food samples, on the other hand, raised only isolated commutability issues. In the organization of a PT-scheme, authentic or artificially inoculated food samples are necessary to accurately evaluate the analytical performances. Reference materials, used as PT items because of their convenience, may present commutability issues leading to inaccurate penalizing conclusions for methods that would have provided accurate results on food samples. For the first time, the commutability of food microbiology PT samples was investigated. The nature of the samples provided by the organizer turned out to be an important factor because matrix effects can impact on the analytical results. © 2013

  8. Design-based estimators for snowball sampling

    OpenAIRE

    Shafie, Termeh

    2010-01-01

    Snowball sampling, where existing study subjects recruit further subjects from amongtheir acquaintances, is a popular approach when sampling from hidden populations.Since people with many in-links are more likely to be selected, there will be a selectionbias in the samples obtained. In order to eliminate this bias, the sample data must beweighted. However, the exact selection probabilities are unknown for snowball samplesand need to be approximated in an appropriate way. This paper proposes d...

  9. Sampling, feasibility, and priors in Bayesian estimation

    OpenAIRE

    Chorin, Alexandre J.; Lu, Fei; Miller, Robert N.; Morzfeld, Matthias; Tu, Xuemin

    2015-01-01

    Importance sampling algorithms are discussed in detail, with an emphasis on implicit sampling, and applied to data assimilation via particle filters. Implicit sampling makes it possible to use the data to find high-probability samples at relatively low cost, making the assimilation more efficient. A new analysis of the feasibility of data assimilation is presented, showing in detail why feasibility depends on the Frobenius norm of the covariance matrix of the noise and not on the number of va...

  10. The Outcome of Thoracentesis versus Chest Tube Placement for Hepatic Hydrothorax in Patients with Cirrhosis: A Nationwide Analysis of the National Inpatient Sample

    Directory of Open Access Journals (Sweden)

    Ali Ridha

    2017-01-01

    Full Text Available There are only a few studies with a small sample size of patients that have compared the risks of using chest tubes versus thoracentesis in hepatic hydrothorax. It has been shown that many complications may arise secondary to chest tube placement and is associated with increased morbidity and mortality. In this retrospective study, patients with cirrhosis were identified from the 2009 National Inpatient Sample by using ICD-9 codes; we evaluated the risk of chest tube versus thoracentesis in a largest population with hepatic hydrothorax to date to measure the mortality and the length of stay. A total of 140,573 patients with liver cirrhosis were identified. Of this, 1981 patients had a hepatic hydrothorax and ended up with either thoracentesis (1776 or chest tube (205. The mortality in those who received a chest tube was two times higher than that in thoracentesis group with a P value of ≤0.001 (CI 1.43–312. In addition, the length of hospital stay of the chest tube group was longer than that of the thoracentesis subset (7.2 days versus 3.8 days, resp.. We concluded that chest tube placement has two times higher mortality rate and longer hospital length of stay when compared to patients who underwent thoracentesis.

  11. Planetary Sample Caching System Design Options

    Science.gov (United States)

    Collins, Curtis; Younse, Paulo; Backes, Paul

    2009-01-01

    Potential Mars Sample Return missions would aspire to collect small core and regolith samples using a rover with a sample acquisition tool and sample caching system. Samples would need to be stored in individual sealed tubes in a canister that could be transfered to a Mars ascent vehicle and returned to Earth. A sample handling, encapsulation and containerization system (SHEC) has been developed as part of an integrated system for acquiring and storing core samples for application to future potential MSR and other potential sample return missions. Requirements and design options for the SHEC system were studied and a recommended design concept developed. Two families of solutions were explored: 1)transfer of a raw sample from the tool to the SHEC subsystem and 2)transfer of a tube containing the sample to the SHEC subsystem. The recommended design utilizes sample tool bit change out as the mechanism for transferring tubes to and samples in tubes from the tool. The SHEC subsystem design, called the Bit Changeout Caching(BiCC) design, is intended for operations on a MER class rover.

  12. Low power and low spur sampling PLL

    NARCIS (Netherlands)

    Gao, X.; Klumperink, Eric A.M.; Bahai, A.; Bohsali, M.; Nauta, Bram; Djabbari, A.; Socci, G.

    2010-01-01

    Abstract Control circuitry and method of controlling a sampling phase locked loop (PLL). By controlling the duty cycle of one or more sampling control signals, power consumption by the reference signal buffer and spurious output signals from the sampling PLL being controlled can be reduced.

  13. Low power and low spur sampling PLL

    NARCIS (Netherlands)

    Gao, X.; Bahai, Ahmad; Bohsali, Mounhir; Djabbari, Ali; Klumperink, Eric A.M.; Nauta, Bram; Socci, Gerard

    2013-01-01

    Abstract Control circuitry and method of controlling a sampling phase locked loop (PLL). By controlling the duty cycle of one or more sampling control signals, power consumption by the reference signal buffer and spurious output signals from the sampling PLL being controlled can be reduced.

  14. 40 CFR 141.703 - Sampling locations.

    Science.gov (United States)

    2010-07-01

    ... samples prior to the point of filter backwash water addition. (d) Bank filtration. (1) Systems that... applicable, must collect source water samples in the surface water prior to bank filtration. (2) Systems that use bank filtration as pretreatment to a filtration plant must collect source water samples from the...

  15. Mounting Thin Samples For Electrical Measurements

    Science.gov (United States)

    Matus, L. G.; Summers, R. L.

    1988-01-01

    New method for mounting thin sample for electrical measurements involves use of vacuum chuck to hold a ceramic mounting plate, which holds sample. Contacts on mounting plate establish electrical connection to sample. Used to make electrical measurements over temperature range from 77 to 1,000 K and does not introduce distortions into magnetic field during Hall measurements.

  16. The new LLNL AMS sample changer

    International Nuclear Information System (INIS)

    Roberts, M.L.; Norman, P.J.; Garibaldi, J.L.; Hornady, R.S.

    1993-01-01

    The Center for Accelerator Mass Spectrometry at LLNL has installed a new 64 position AMS sample changer on our spectrometer. This new sample changer has the capability of being controlled manually by an operator or automatically by the AMS data acquisition computer. Automatic control of the sample changer by the data acquisition system is a necessary step towards unattended AMS operation in our laboratory. The sample changer uses a fiber optic shaft encoder for rough rotational indexing of the sample wheel and a series of sequenced pneumatic cylinders for final mechanical indexing of the wheel and insertion and retraction of samples. Transit time from sample to sample varies from 4 s to 19 s, depending on distance moved. Final sample location can be set to within 50 microns on the x and y axis and within 100 microns in the z axis. Changing sample wheels on the new sample changer is also easier and faster than was possible on our previous sample changer and does not require the use of any tools

  17. NASA Lunar and Meteorite Sample Disk Program

    Science.gov (United States)

    Foxworth, Suzanne

    2017-01-01

    The Lunar and Meteorite Sample Disk Program is designed for K-12 classroom educators who work in K-12 schools, museums, libraries, or planetariums. Educators have to be certified to borrow the Lunar and Meteorite Sample Disks by attending a NASA Certification Workshop provided by a NASA Authorized Sample Disk Certifier.

  18. Sample and data management process description

    International Nuclear Information System (INIS)

    Kessner, J.H.

    2000-01-01

    The sample and data management process was initiated in 1994 as a result of a process improvement workshop. The purpose of the workshop was to develop a sample and data management process that would reduce cycle time and costs, simplify systems and procedures, and improve customer satisfaction for sampling, analytical services, and data management activities

  19. Radioactivity level of different cinnamon samples

    Energy Technology Data Exchange (ETDEWEB)

    Czegledi, P; Cieleszky, V [Institut of Nutrition, Budapest (Hungry); Andrasi, A; Zombori, P [Koezponti Fizikai Kutato Intezet, Budapest (Hungary)

    1980-06-01

    /sup 40/K, /sup 90/Sr, /sup 137/Cs, /sup 226/Ra, and /sup 232/Th were determined in cinnamon samples from China, Sri Lanka and Indonesia. The Chinese sample contained an extremenly high quantity of /sup 90/Sr and its /sup 137/Cs content was also considerably higher than that of the other samples.

  20. An introduction to automatic radioactive sample counters

    International Nuclear Information System (INIS)

    1980-01-01

    The subject is covered in chapters, entitled; the detection of radiation in sample counters; nucleonic equipment; liquid scintillation counting; basic features of automatic sample counters; statistics of counting; data analysis; purchase, installation, calibration and maintenance of automatic sample counters. (U.K.)

  1. METABOLITE CHARACTERIZATION IN SERUM SAMPLES FROM ...

    African Journals Online (AJOL)

    Preferred Customer

    fasting 10 mL of blood sample from each individual was taken and was allowed to clot in plastic tube for 2 h at room temperature. The serum was collected by centrifugation. The samples were stored under liquid nitrogen for NMR analysis. Before NMR analysis, 600 µL of the samples were taken in a 5 mm high quality NMR ...

  2. 40 CFR 61.44 - Stack sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Stack sampling. 61.44 Section 61.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Firing § 61.44 Stack sampling. (a) Sources subject to § 61.42(b) shall be continuously sampled, during...

  3. 16 CFR 305.6 - Sampling.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Sampling. 305.6 Section 305.6 Commercial... ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Testing § 305.6 Sampling. (a) For any... based upon the sampling procedures set forth in § 430.24 of 10 CFR part 430, subpart B. (b) For any...

  4. 7 CFR 75.18 - Sampling.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Sampling. 75.18 Section 75.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections... CERTIFICATION OF QUALITY OF AGRICULTURAL AND VEGETABLE SEEDS Inspection § 75.18 Sampling. Sampling, when...

  5. 40 CFR 61.54 - Sludge sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Sludge sampling. 61.54 Section 61.54... sampling. (a) As an alternative means for demonstrating compliance with § 61.52(b), an owner or operator... days prior to a sludge sampling test, so that he may at his option observe the test. (c) Sludge shall...

  6. 19 CFR 151.10 - Sampling.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Sampling. 151.10 Section 151.10 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE General § 151.10 Sampling. When necessary, the port director...

  7. 40 CFR 761.348 - Contemporaneous sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Contemporaneous sampling. 761.348... PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product Waste for Purposes of Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation Waste Destined for Off-Site Disposal...

  8. Sample normalization methods in quantitative metabolomics.

    Science.gov (United States)

    Wu, Yiman; Li, Liang

    2016-01-22

    To reveal metabolomic changes caused by a biological event in quantitative metabolomics, it is critical to use an analytical tool that can perform accurate and precise quantification to examine the true concentration differences of individual metabolites found in different samples. A number of steps are involved in metabolomic analysis including pre-analytical work (e.g., sample collection and storage), analytical work (e.g., sample analysis) and data analysis (e.g., feature extraction and quantification). Each one of them can influence the quantitative results significantly and thus should be performed with great care. Among them, the total sample amount or concentration of metabolites can be significantly different from one sample to another. Thus, it is critical to reduce or eliminate the effect of total sample amount variation on quantification of individual metabolites. In this review, we describe the importance of sample normalization in the analytical workflow with a focus on mass spectrometry (MS)-based platforms, discuss a number of methods recently reported in the literature and comment on their applicability in real world metabolomics applications. Sample normalization has been sometimes ignored in metabolomics, partially due to the lack of a convenient means of performing sample normalization. We show that several methods are now available and sample normalization should be performed in quantitative metabolomics where the analyzed samples have significant variations in total sample amounts. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Radar Doppler Processing with Nonuniform Sampling.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-01

    Conventional signal processing to estimate radar Doppler frequency often assumes uniform pulse/sample spacing. This is for the convenience of t he processing. More recent performance enhancements in processor capability allow optimally processing nonuniform pulse/sample spacing, thereby overcoming some of the baggage that attends uniform sampling, such as Doppler ambiguity and SNR losses due to sidelobe control measures.

  10. Sampling soils for transuranic nuclides: a review

    International Nuclear Information System (INIS)

    Fowler, E.B.; Essington, E.H.

    1976-01-01

    A review of the literature pertinent to the sampling of soils for radionuclides is presented; emphasis is placed on transuranic nuclides. Sampling of soils is discussed relative to systems of heterogeneous distributions and varied particle sizes encountered in certain environments. Sampling methods that have been used for two different sources of contamination, global fallout, and accidental or operational releases, are included

  11. Mixed Methods Sampling: A Typology with Examples

    Science.gov (United States)

    Teddlie, Charles; Yu, Fen

    2007-01-01

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

  12. Sample management implementation plan: Salt Repository Project

    International Nuclear Information System (INIS)

    1987-01-01

    The purpose of the Sample Management Implementation Plan is to define management controls and building requirements for handling materials collected during the site characterization of the Deaf Smith County, Texas, site. This work will be conducted for the US Department of Energy Salt Repository Project Office (SRPO). The plan provides for controls mandated by the US Nuclear Regulatory Commission and the US Environmental Protection Agency. Salt Repository Project (SRP) Sample Management will interface with program participants who request, collect, and test samples. SRP Sample Management will be responsible for the following: (1) preparing samples; (2) ensuring documentation control; (3) providing for uniform forms, labels, data formats, and transportation and storage requirements; and (4) identifying sample specifications to ensure sample quality. The SRP Sample Management Facility will be operated under a set of procedures that will impact numerous program participants. Requesters of samples will be responsible for definition of requirements in advance of collection. Sample requests for field activities will be approved by the SRPO, aided by an advisory group, the SRP Sample Allocation Committee. This document details the staffing, building, storage, and transportation requirements for establishing an SRP Sample Management Facility. Materials to be managed in the facility include rock core and rock discontinuities, soils, fluids, biota, air particulates, cultural artifacts, and crop and food stuffs. 39 refs., 3 figs., 11 tabs

  13. The Effect of Asymmetrical Sample Training on Retention Functions for Hedonic Samples in Rats

    Science.gov (United States)

    Simmons, Sabrina; Santi, Angelo

    2012-01-01

    Rats were trained in a symbolic delayed matching-to-sample task to discriminate sample stimuli that consisted of the presence of food or the absence of food. Asymmetrical sample training was provided in which one group was initially trained with only the food sample and the other group was initially trained with only the no-food sample. In…

  14. Diagnostic herd sensitivity using environmental samples

    DEFF Research Database (Denmark)

    Vigre, Håkan; Josefsen, Mathilde Hartmann; Seyfarth, Anne Mette

    either at farm or slaughter. Three sample matrices were collected; dust samples (5 environmental swabs), nasal swabs (10 pools with 5 animals per pool) and air samples (1 filter). Based on the assumption that MRSA occurred in all 48 herds the overall herd sensitivity was 58% for nasal swabs, 33% for dust....... In our example, the prevalence of infected pigs in each herd was estimated from the pooled samples of nasal swabs. Logistic regression was used to estimate the effect of animal prevalence on the probability to detect MRSA in the dust and air samples at herd level. The results show a significant increase...

  15. Handling missing data in ranked set sampling

    CERN Document Server

    Bouza-Herrera, Carlos N

    2013-01-01

    The existence of missing observations is a very important aspect to be considered in the application of survey sampling, for example. In human populations they may be caused by a refusal of some interviewees to give the true value for the variable of interest. Traditionally, simple random sampling is used to select samples. Most statistical models are supported by the use of samples selected by means of this design. In recent decades, an alternative design has started being used, which, in many cases, shows an improvement in terms of accuracy compared with traditional sampling. It is called R

  16. Where Will All Your Samples Go?

    Science.gov (United States)

    Lehnert, K.

    2017-12-01

    Even in the digital age, physical samples remain an essential component of Earth and space science research. Geoscientists collect samples, sometimes locally, often in remote locations during expensive field expeditions, or at sample repositories and museums. They take these samples to their labs to describe and analyze them. When the analyses are completed and the results are published, the samples get stored away in sheds, basements, or desk drawers, where they remain unknown and inaccessible to the broad science community. In some cases, they will get re-analyzed or shared with other researchers, who know of their existence through personal connections. The sad end comes when the researcher retires: There are many stories of samples and entire collections being discarded to free up space for new samples or other purposes, even though these samples may be unique and irreplaceable. Institutions do not feel obligated and do not have the resources to store samples in perpetuity. Only samples collected in large sampling campaigns such as the Ocean Discovery Program or cores taken on ships find a home in repositories that curate and preserve them for reuse in future science endeavors. In the era of open, transparent, and reproducible science, preservation and persistent access to samples must be considered a mandate. Policies need to be developed that guide investigators, institutions, and funding agencies to plan and implement solutions for reliably and persistently curating and providing access to samples. Registration of samples in online catalogs and use of persistent identifiers such as the International Geo Sample Number are first steps to ensure discovery and access of samples. But digital discovery and access loses its value if the physical objects are not preserved and accessible. It is unreasonable to expect that every sample ever collected can be archived. Selection of those samples that are worth preserving requires guidelines and policies. We also need to

  17. A Consistent System for Coding Laboratory Samples

    Science.gov (United States)

    Sih, John C.

    1996-07-01

    A formal laboratory coding system is presented to keep track of laboratory samples. Preliminary useful information regarding the sample (origin and history) is gained without consulting a research notebook. Since this system uses and retains the same research notebook page number for each new experiment (reaction), finding and distinguishing products (samples) of the same or different reactions becomes an easy task. Using this system multiple products generated from a single reaction can be identified and classified in a uniform fashion. Samples can be stored and filed according to stage and degree of purification, e.g. crude reaction mixtures, recrystallized samples, chromatographed or distilled products.

  18. Sample size in qualitative interview studies

    DEFF Research Database (Denmark)

    Malterud, Kirsti; Siersma, Volkert Dirk; Guassora, Ann Dorrit Kristiane

    2016-01-01

    Sample sizes must be ascertained in qualitative studies like in quantitative studies but not by the same means. The prevailing concept for sample size in qualitative studies is “saturation.” Saturation is closely tied to a specific methodology, and the term is inconsistently applied. We propose...... the concept “information power” to guide adequate sample size for qualitative studies. Information power indicates that the more information the sample holds, relevant for the actual study, the lower amount of participants is needed. We suggest that the size of a sample with sufficient information power...... and during data collection of a qualitative study is discussed....

  19. Radiochemical analysis of phosphorus in milk samples

    International Nuclear Information System (INIS)

    Oliveira, R.M. de; Cunha, I.I.L.

    1991-01-01

    The determination of phosphorus in milk samples by thermal neutron activation analysis employing radiochemical separation is described. The radiochemical separation consists of the simultaneous irradiation of samples and standards, dissolution of the milk samples in a perchloric acid and nitric acid mixture, addition of zinc hold-back carrier, precipitation of phosphorus as ammonium phospho molybdate (A.M.P.) and sample counting in a Geiger-Mueller detector. The analysis sources of error were studied and the established method was applied to phosphorus analyses in commercial milk samples. (author)

  20. Guidance for air sampling at nuclear facilities

    International Nuclear Information System (INIS)

    Breslin, A.J.

    1976-11-01

    The principal uses of air sampling at nuclear facilities are to monitor general levels of radioactive air contamination, identify sources of air contamination, and evaluate the effectiveness of contaminant control equipment, determine exposures of individual workers, and provide automatic warning of hazardous concentrations of radioactivity. These applications of air sampling are discussed with respect to standards of occupational exposure, instrumentation, sample analysis, sampling protocol, and statistical treatment of concentration data. Emphasis is given to the influence of spacial and temporal variations of radionuclide concentration on the location, duration, and frequency of air sampling

  1. Rotary Mode Core Sample System availability improvement

    International Nuclear Information System (INIS)

    Jenkins, W.W.; Bennett, K.L.; Potter, J.D.; Cross, B.T.; Burkes, J.M.; Rogers, A.C.

    1995-01-01

    The Rotary Mode Core Sample System (RMCSS) is used to obtain stratified samples of the waste deposits in single-shell and double-shell waste tanks at the Hanford Site. The samples are used to characterize the waste in support of ongoing and future waste remediation efforts. Four sampling trucks have been developed to obtain these samples. Truck I was the first in operation and is currently being used to obtain samples where the push mode is appropriate (i.e., no rotation of drill). Truck 2 is similar to truck 1, except for added safety features, and is in operation to obtain samples using either a push mode or rotary drill mode. Trucks 3 and 4 are now being fabricated to be essentially identical to truck 2

  2. Calibration samples for accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Hershberger, R.L.; Flynn, D.S.; Gabbard, F.

    1981-01-01

    Radioactive samples with precisely known numbers of atoms are useful as calibration sources for lifetime measurements using accelerator mass spectrometry. Such samples can be obtained in two ways: either by measuring the production rate as the sample is created or by measuring the decay rate after the sample has been obtained. The latter method requires that a large sample be produced and that the decay constant be accurately known. The former method is a useful and independent alternative, especially when the decay constant is not well known. The facilities at the University of Kentucky for precision measurements of total neutron production cross sections offer a source of such calibration samples. The possibilities, while quite extensive, would be limited to the proton rich side of the line of stability because of the use of (p,n) and (α,n) reactions for sample production

  3. Attenuation of species abundance distributions by sampling

    Science.gov (United States)

    Shimadzu, Hideyasu; Darnell, Ross

    2015-01-01

    Quantifying biodiversity aspects such as species presence/ absence, richness and abundance is an important challenge to answer scientific and resource management questions. In practice, biodiversity can only be assessed from biological material taken by surveys, a difficult task given limited time and resources. A type of random sampling, or often called sub-sampling, is a commonly used technique to reduce the amount of time and effort for investigating large quantities of biological samples. However, it is not immediately clear how (sub-)sampling affects the estimate of biodiversity aspects from a quantitative perspective. This paper specifies the effect of (sub-)sampling as attenuation of the species abundance distribution (SAD), and articulates how the sampling bias is induced to the SAD by random sampling. The framework presented also reveals some confusion in previous theoretical studies. PMID:26064626

  4. On Invertible Sampling and Adaptive Security

    DEFF Research Database (Denmark)

    Ishai, Yuval; Kumarasubramanian, Abishek; Orlandi, Claudio

    2011-01-01

    functionalities was left open. We provide the first convincing evidence that the answer to this question is negative, namely that some (randomized) functionalities cannot be realized with adaptive security. We obtain this result by studying the following related invertible sampling problem: given an efficient...... sampling algorithm A, obtain another sampling algorithm B such that the output of B is computationally indistinguishable from the output of A, but B can be efficiently inverted (even if A cannot). This invertible sampling problem is independently motivated by other cryptographic applications. We show......, under strong but well studied assumptions, that there exist efficient sampling algorithms A for which invertible sampling as above is impossible. At the same time, we show that a general feasibility result for adaptively secure MPC implies that invertible sampling is possible for every A, thereby...

  5. Sexual risk as an outcome of social oppression: data from a probability sample of Latino gay men in three U.S. cities.

    Science.gov (United States)

    Díaz, Rafael M; Ayala, George; Bein, Edward

    2004-08-01

    Based on data from a probability sample of 912 Latino gay men in 3 U.S. cities, a multivariate model of sexual risk was tested, including experiences of homophobia, racism, and poverty as predictors. Participants reported multiple instances of verbal and physical abuse, rude mistreatment, and discrimination on account of their sexual orientation and their race or ethnicity. Many reported experiences of poverty, such as inability to pay for basic necessities of food or shelter. Men who reported more instances of social discrimination and financial hardship were more psychologically distressed and more likely to participate in "difficult" sexual situations, as predicted. Participation in difficult sexual situations mediates the effects of social oppression and psychological distress on sexual risk behavior. (c) 2004 APA

  6. Maintaining continuity of knowledge on safeguards samples

    International Nuclear Information System (INIS)

    Franssen, F.; Islam, A.B.M.N.; Sonnier, C.; Schoeneman, J.L.; Baumann, M.

    1992-01-01

    The conclusions of the vulnerability test on VOPAN (verification of Operator's Analysis) as conducted at Safeguards Analytical Laboratory (ASA) at Seibersdorf, Austria in October 1990 and documented in STR-266, indicate that ''whenever samples are taken for safeguards purposes extreme care must be taken to ensure that they have not been interfered with during the sample taking, transportation, storage or sample preparation process.'' Indeed there exist a number of possibilities to alter the content of a safeguards sample vial from the moment of sampling up to the arrival of the treated (or untreated) sample at SAL. The time lapse between these two events can range from a few days up to months. The sample history over this period can be subdivided into three main sub-periods: (1) the period from when the sampling activities are commenced up to the treatment in the operator's laboratory, (2) during treatment of samples in the operator's laboratory, and finally, (3) the period between that treatment and the arrival of the sample at SAL. A combined effort between the Agency and the United States Support Program to the Agency (POTAS) has resulted in two active tasks and one proposed task to investigate improving the maintenance of continuity of knowledge on safeguards samples during the entire period of their existence. This paper describes the use of the Sample Vial Secure Container (SVSC), of the Authenticated Secure Container System (ASCS), and of the Secure Container for Storage and Transportation of samples (SCST) to guarantee that a representative portion of the solution sample will be received at SAL

  7. Quality evaluation of processed clay soil samples.

    Science.gov (United States)

    Steiner-Asiedu, Matilda; Harrison, Obed Akwaa; Vuvor, Frederick; Tano-Debrah, Kwaku

    2016-01-01

    This study assessed the microbial quality of clay samples sold on two of the major Ghanaian markets. The study was a cross-sectional assessing the evaluation of processed clay and effects it has on the nutrition of the consumers in the political capital town of Ghana. The items for the examination was processed clay soil samples. Staphylococcus spp and fecal coliforms including Klebsiella, Escherichia, and Shigella and Enterobacterspp were isolated from the clay samples. Samples from the Kaneshie market in Accra recorded the highest total viable counts 6.5 Log cfu/g and Staphylococcal count 5.8 Log cfu/g. For fecal coliforms, Madina market samples had the highest count 6.5 Log cfu/g and also recorded the highest levels of yeast and mould. For Koforidua, total viable count was highest in the samples from the Zongo market 6.3 Log cfu/g. Central market samples had the highest count of fecal coliforms 4.6 Log cfu/g and yeasts and moulds 6.5 Log cfu/g. "Small" market recorded the highest staphylococcal count 6.2 Log cfu/g. The water activity of the clay samples were low, and ranged between 0.65±0.01 and 0.66±0.00 for samples collected from Koforidua and Accra respectively. The clay samples were found to contain Klebsiella spp. Escherichia, Enterobacter, Shigella spp. staphylococcus spp., yeast and mould. These have health implications when consumed.

  8. Preferential sampling in veterinary parasitological surveillance

    Directory of Open Access Journals (Sweden)

    Lorenzo Cecconi

    2016-04-01

    Full Text Available In parasitological surveillance of livestock, prevalence surveys are conducted on a sample of farms using several sampling designs. For example, opportunistic surveys or informative sampling designs are very common. Preferential sampling refers to any situation in which the spatial process and the sampling locations are not independent. Most examples of preferential sampling in the spatial statistics literature are in environmental statistics with focus on pollutant monitors, and it has been shown that, if preferential sampling is present and is not accounted for in the statistical modelling and data analysis, statistical inference can be misleading. In this paper, working in the context of veterinary parasitology, we propose and use geostatistical models to predict the continuous and spatially-varying risk of a parasite infection. Specifically, breaking with the common practice in veterinary parasitological surveillance to ignore preferential sampling even though informative or opportunistic samples are very common, we specify a two-stage hierarchical Bayesian model that adjusts for preferential sampling and we apply it to data on Fasciola hepatica infection in sheep farms in Campania region (Southern Italy in the years 2013-2014.

  9. A Improved Seabed Surface Sand Sampling Device

    Science.gov (United States)

    Luo, X.

    2017-12-01

    In marine geology research it is necessary to obtain a suf fcient quantity of seabed surface samples, while also en- suring that the samples are in their original state. Currently,there are a number of seabed surface sampling devices available, but we fnd it is very diffcult to obtain sand samples using these devices, particularly when dealing with fne sand. Machine-controlled seabed surface sampling devices are also available, but generally unable to dive into deeper regions of water. To obtain larger quantities of seabed surface sand samples in their original states, many researchers have tried to improve upon sampling devices,but these efforts have generally produced ambiguous results, in our opinion.To resolve this issue, we have designed an improved andhighly effective seabed surface sand sampling device that incorporates the strengths of a variety of sampling devices. It is capable of diving into deepwater to obtain fne sand samples and is also suited for use in streams, rivers, lakes and seas with varying levels of depth (up to 100 m). This device can be used for geological mapping, underwater prospecting, geological engineering and ecological, environmental studies in both marine and terrestrial waters.

  10. Uncertainty and sampling issues in tank characterization

    International Nuclear Information System (INIS)

    Liebetrau, A.M.; Pulsipher, B.A.; Kashporenko, D.M.

    1997-06-01

    A defensible characterization strategy must recognize that uncertainties are inherent in any measurement or estimate of interest and must employ statistical methods for quantifying and managing those uncertainties. Estimates of risk and therefore key decisions must incorporate knowledge about uncertainty. This report focuses statistical methods that should be employed to ensure confident decision making and appropriate management of uncertainty. Sampling is a major source of uncertainty that deserves special consideration in the tank characterization strategy. The question of whether sampling will ever provide the reliable information needed to resolve safety issues is explored. The issue of sample representativeness must be resolved before sample information is reliable. Representativeness is a relative term but can be defined in terms of bias and precision. Currently, precision can be quantified and managed through an effective sampling and statistical analysis program. Quantifying bias is more difficult and is not being addressed under the current sampling strategies. Bias could be bounded by (1) employing new sampling methods that can obtain samples from other areas in the tanks, (2) putting in new risers on some worst case tanks and comparing the results from existing risers with new risers, or (3) sampling tanks through risers under which no disturbance or activity has previously occurred. With some bound on bias and estimates of precision, various sampling strategies could be determined and shown to be either cost-effective or infeasible

  11. Sampling device for radioactive molten salt

    International Nuclear Information System (INIS)

    Shindo, Masato

    1998-01-01

    The present invention provides a device for accurately sampling molten salts to which various kinds of metals in a molten salt storage tank are mixed for analyzing them during a spent fuel dry type reprocessing. Namely, the device comprises a sampling tube having an opened lower end to be inserted into the radioactive molten salts stored in a tank and keeps reduced pressure from the upper end, and a pressure reducing pipeline having one end connected to the sampling tube and other end connected to an evacuating pump. In this device, the top end of the sampling tube is inserted to a position for sampling the radioactive molten salts (molten salts). The pressure inside the evacuating pipeline connected to the upper portion of the sampling tube is reduced for a while. In this case, the inside of the pressure reducing pipeline is previously evacuated by the evacuating pump so as to keep a predetermined pressure. Since the pressure in the sampling tube is lowered, molten salts are inserted into the sampling tube, the sampling tube is withdrawn, and the molten salts flown in the sampling tube are analyzed. (I.S.)

  12. Soil Gas Sample Handling: Evaluation of Water Removal and Sample Ganging

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, Brad G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Abrecht, David G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hayes, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mendoza, Donaldo P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-10-31

    Soil gas sampling is currently conducted in support of Nuclear Test Ban treaty verification. Soil gas samples are collected and analyzed for isotopes of interest. Some issues that can impact sampling and analysis of these samples are excess moisture and sample processing time. Here we discuss three potential improvements to the current sampling protocol; a desiccant for water removal, use of molecular sieve to remove CO2 from the sample during collection, and a ganging manifold to allow composite analysis of multiple samples.

  13. [Sample preparation and bioanalysis in mass spectrometry].

    Science.gov (United States)

    Bourgogne, Emmanuel; Wagner, Michel

    2015-01-01

    The quantitative analysis of compounds of clinical interest of low molecular weight (sample preparation. Sample preparation is a crucial part of chemical/biological analysis and in a sense is considered the bottleneck of the whole analytical process. The main objectives of sample preparation are the removal of potential interferences, analyte preconcentration, and converting (if needed) the analyte into a more suitable form for detection or separation. Without chromatographic separation, endogenous compounds, co-eluted products may affect a quantitative method in mass spectrometry performance. This work focuses on three distinct parts. First, quantitative bioanalysis will be defined, different matrices and sample preparation techniques currently used in bioanalysis by mass spectrometry of/for small molecules of clinical interest in biological fluids. In a second step the goals of sample preparation will be described. Finally, in a third step, sample preparation strategies will be made either directly ("dilute and shoot") or after precipitation.

  14. Advances in Radiocarbon Measurement of Water Samples

    Energy Technology Data Exchange (ETDEWEB)

    Janovics, R.; Molnar, M.; Major, I. [Institute of Nuclear Research (ATO MKI), Hungarian Academy of Sciences, H-4001 Debrecen (Hungary); Svetlik, I. [Department of Radiation Dosimetry, Nuclear Physics Institute AS CR, Prague (Czech Republic); Wacker, L. [Institute for Particle Physics, ETH Hoenggerberg, Zuerich (Switzerland)

    2013-07-15

    In this paper two very different and novel methods for the {sup 14}C measurement of water samples are presented. The first method uses direct absorption into a scintillation cocktail and a following liquid scintillation measurement. Typical sample size is 20-40 L and overall uncertainty is {+-} 2% for modern samples. It is a very cost effective and easy to use method based on a novel and simple static absorption process for the CO{sub 2} extracted from groundwater. The other very sensitive method is based on accelerator mass spectrometry (AMS) using a gas ion source. With a MICADAS type AMS system we demonstrated that you can routinely measure the {sup 14}C content of 1 mL of water sample with better than 1% precision (for a modern sample). This direct {sup 14}C AMS measurement of water takes less than 20 minutes including sample preparation. (author)

  15. 100 Area Columbia River sediment sampling

    International Nuclear Information System (INIS)

    Weiss, S.G.

    1993-01-01

    Forty-four sediment samples were collected from 28 locations in the Hanford Reach of the Columbia River to assess the presence of metals and man-made radionuclides in the near shore and shoreline settings of the Hanford Site. Three locations were sampled upriver of the Hanford Site plutonium production reactors. Twenty-two locations were sampled near the reactors. Three locations were sampled downstream of the reactors near the Hanford Townsite. Sediment was collected from depths of 0 to 6 in. and between 12 to 24 in. below the surface. Samples containing concentrations of metals exceeding the 95 % upper threshold limit values (DOE-RL 1993b) are considered contaminated. Contamination by arsenic, chromium, copper, lead, and zinc was found. Man-made radionuclides occur in all samples except four collected opposite the Hanford Townsite. Man-made radionuclide concentrations were generally less than 1 pCi/g

  16. 100 Area Columbia River sediment sampling

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, S.G. [Westinghouse Hanford Co., Richland, WA (United States)

    1993-09-08

    Forty-four sediment samples were collected from 28 locations in the Hanford Reach of the Columbia River to assess the presence of metals and man-made radionuclides in the near shore and shoreline settings of the Hanford Site. Three locations were sampled upriver of the Hanford Site plutonium production reactors. Twenty-two locations were sampled near the reactors. Three locations were sampled downstream of the reactors near the Hanford Townsite. Sediment was collected from depths of 0 to 6 in. and between 12 to 24 in. below the surface. Samples containing concentrations of metals exceeding the 95 % upper threshold limit values (DOE-RL 1993b) are considered contaminated. Contamination by arsenic, chromium, copper, lead, and zinc was found. Man-made radionuclides occur in all samples except four collected opposite the Hanford Townsite. Man-made radionuclide concentrations were generally less than 1 pCi/g.

  17. Device for sampling liquid radioactive materials

    International Nuclear Information System (INIS)

    Vlasak, L.

    1987-01-01

    Remote sampling of radioactive materials in the process of radioactive waste treatment is claimed by the Czechoslovak Patent Document 238599. The existing difficulties are eliminated consisting in a complex remote control of sampling featuring the control of sliding and rotary movements of the sampling device. The new device consists of a vertical pipe with an opening provided with a cover. A bend is provided above the opening level housing flow distributors. A sampling tray is pivoted in the cover. In sampling, the tray is tilted in the vertical pipe space while it tilts back when filled. The sample flows into a vessel below the tray. Only rotary movement is thus sufficient for controlling the tray. (Z.M.)

  18. Direct impact aerosol sampling by electrostatic precipitation

    Science.gov (United States)

    Braden, Jason D.; Harter, Andrew G.; Stinson, Brad J.; Sullivan, Nicholas M.

    2016-02-02

    The present disclosure provides apparatuses for collecting aerosol samples by ionizing an air sample at different degrees. An air flow is generated through a cavity in which at least one corona wire is disposed and electrically charged to form a corona therearound. At least one grounded sample collection plate is provided downstream of the at least one corona wire so that aerosol ions generated within the corona are deposited on the at least one grounded sample collection plate. A plurality of aerosol samples ionized to different degrees can be generated. The at least one corona wire may be perpendicular to the direction of the flow, or may be parallel to the direction of the flow. The apparatus can include a serial connection of a plurality of stages such that each stage is capable of generating at least one aerosol sample, and the air flow passes through the plurality of stages serially.

  19. Sample Curation at a Lunar Outpost

    Science.gov (United States)

    Allen, Carlton C.; Lofgren, Gary E.; Treiman, A. H.; Lindstrom, Marilyn L.

    2007-01-01

    The six Apollo surface missions returned 2,196 individual rock and soil samples, with a total mass of 381.6 kg. Samples were collected based on visual examination by the astronauts and consultation with geologists in the science back room in Houston. The samples were photographed during collection, packaged in uniquely-identified containers, and transported to the Lunar Module. All samples collected on the Moon were returned to Earth. NASA's upcoming return to the Moon will be different. Astronauts will have extended stays at an out-post and will collect more samples than they will return. They will need curation and analysis facilities on the Moon in order to carefully select samples for return to Earth.

  20. Teknik Sampling Snowball dalam Penelitian Lapangan

    Directory of Open Access Journals (Sweden)

    Nina Nurdiani

    2014-12-01

    Full Text Available Field research can be associated with both qualitative and quantitative research methods, depending on the problems faced and the goals to be achieved. The success of data collection in the field research depends on the determination of the appropriate sampling technique, to obtain accurate data, and reliably. In studies that have problems related to specific issues, requiring a non-probability sampling techniques one of which is the snowball sampling technique. This technique is useful for finding, identifying, selecting and taking samples in a network or chain of relationships. Phased implementation procedures performed through interviews and questionnaires. Snowball sampling technique has strengths and weaknesses in its application. Field research housing sector become the case study to explain this sampling technique.

  1. Electrical discharge machining for vessel sample removal

    International Nuclear Information System (INIS)

    Litka, T.J.

    1993-01-01

    Due to aging-related problems or essential metallurgy information (plant-life extension or decommissioning) of nuclear plants, sample removal from vessels may be required as part of an examination. Vessel or cladding samples with cracks may be removed to determine the cause of cracking. Vessel weld samples may be removed to determine the weld metallurgy. In all cases, an engineering analysis must be done prior to sample removal to determine the vessel's integrity upon sample removal. Electrical discharge machining (EDM) is being used for in-vessel nuclear power plant vessel sampling. Machining operations in reactor coolant system (RCS) components must be accomplished while collecting machining chips that could cause damage if they become part of the flow stream. The debris from EDM is a fine talclike particulate (no chips), which can be collected by flushing and filtration

  2. Microfabricated Devices for Sample Extraction, Concentrations, and Related Sample Processing Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Gang; Lin, Yuehe

    2006-12-01

    This is an invited book chapter. As with other analytical techniques, sample pretreatments, sample extraction, sample introduction, and related techniques are of extreme importance for micro-electro-mechanical systems (MEMS). Bio-MEMS devices and systems start with a sampling step. The biological sample then usually undergoes some kinds of sample preparation steps before the actual analysis. These steps may involve extracting the target sample from its matrix, removing interferences from the sample, derivatizing the sample to detectable species, or performing a sample preconcentration step. The integration of the components for sample pretreatment into microfluidic devices represents one of the remaining the bottle-neck towards achieving true miniaturized total analysis systems (?TAS). This chapter provides a thorough state-of-art of the developments in this field to date.

  3. Hanford Sampling Quality Management Plan (HSQMP)

    International Nuclear Information System (INIS)

    Hyatt, J.E.

    1995-06-01

    HSQMP establishes quality requirements in response to DOE Order 5700. 6C and to 10 Code of Federal Regulations 830.120. HSQMP is designed to meet the needs of Richland Operations Office for controlling the quality of services provided by sampling operations. It is issued through the Analytical Services Program of the Waste Programs Division. This document describes the Environmental Sampling and Analysis Program activities considered to represent the best management activities necessary to achieve a sampling program with adequate control

  4. Sampling calorimeters in high energy physics

    International Nuclear Information System (INIS)

    Gordon, H.A.; Smith, S.D.

    1980-01-01

    Attention is given to sampling calorimeters - those instruments in which part of the shower is sampled in an active medium sandwiched between absorbing layers. A very cursory overview is presented of some fundamental aspects of sampling calorimeters. First the properties of shower development are described for both the electromagnetic and hadronic cases. Then examples of various readout schemes are discussed. Finally, some currently promising new ideas in calorimetry are described

  5. Measurement of neutron activation in concrete samples

    International Nuclear Information System (INIS)

    Zagar, T.; Ravnik, M.

    2000-01-01

    The results of activation studies of ordinary and barytes concrete samples relevant for research reactor decommissioning are given. Five important long-lived radioactive isotopes ( 54 Mn, 60 Co, 65 Zn, 133 Ba, and 152 Eu) were identified from the gamma-ray spectra measured in the irradiated concrete samples. Activation of these samples was also calculated using ORIGEN2 code. Comparison of calculated and measured results is given. (author)

  6. Stream sediment sampling and analysis. Final report

    International Nuclear Information System (INIS)

    Means, J.L.; Voris, P.V.; Headington, G.L.

    1986-04-01

    The objectives were to sample and analyze sediments from upstream and downstream locations (relative to the Goodyear Atomic plant site) of three streams for selected pollutants. The three streams sampled were the Scioto River, Big Beaver Creek, and Big Run Creek. Sediment samples were analyzed for EPA's 129 priority pollutants (Clean Water Act) as well as isotopic uranium ( 234 U, 235 U, and 238 U) and technetium-99

  7. Innovative methods for inorganic sample preparation

    Energy Technology Data Exchange (ETDEWEB)

    Essling, A.M.; Huff, E.A.; Graczyk, D.G.

    1992-04-01

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

  8. Adaptive Angular Sampling for SPECT Imaging

    OpenAIRE

    Li, Nan; Meng, Ling-Jian

    2011-01-01

    This paper presents an analytical approach for performing adaptive angular sampling in single photon emission computed tomography (SPECT) imaging. It allows for a rapid determination of the optimum sampling strategy that minimizes image variance in regions-of-interest (ROIs). The proposed method consists of three key components: (a) a set of close-form equations for evaluating image variance and resolution attainable with a given sampling strategy, (b) a gradient-based algor...

  9. Flight Vehicle Control and Aerobiological Sampling Applications

    OpenAIRE

    Techy, Laszlo

    2009-01-01

    Aerobiological sampling using unmanned aerial vehicles (UAVs) is an exciting research field blending various scientific and engineering disciplines. The biological data collected using UAVs helps to better understand the atmospheric transport of microorganisms. Autopilot-equipped UAVs can accurately sample along pre-defined flight plans and precisely regulated altitudes. They can provide even greater utility when they are networked together in coordinated sampling missions: such measurements ...

  10. Importance sampling the Rayleigh phase function

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall

    2011-01-01

    Rayleigh scattering is used frequently in Monte Carlo simulation of multiple scattering. The Rayleigh phase function is quite simple, and one might expect that it should be simple to importance sample it efficiently. However, there seems to be no one good way of sampling it in the literature....... This paper provides the details of several different techniques for importance sampling the Rayleigh phase function, and it includes a comparison of their performance as well as hints toward efficient implementation....

  11. Teknik Sampling Snowball dalam Penelitian Lapangan

    OpenAIRE

    Nina Nurdiani

    2014-01-01

    Field research can be associated with both qualitative and quantitative research methods, depending on the problems faced and the goals to be achieved. The success of data collection in the field research depends on the determination of the appropriate sampling technique, to obtain accurate data, and reliably. In studies that have problems related to specific issues, requiring a non-probability sampling techniques one of which is the snowball sampling technique. This technique is useful for f...

  12. METALLOGRAPHIC SAMPLE PREPARATION STATION-CONSTRUCTIVE CONCEPT

    Directory of Open Access Journals (Sweden)

    AVRAM Florin Timotei

    2016-11-01

    Full Text Available In this paper we propose to present the issues involved in the case of the constructive conception of a station for metallographic sample preparation. This station is destined for laboratory work. The metallographic station is composed of a robot ABB IRB1600, a metallographic microscope, a gripping device, a manipulator, a laboratory grinding and polishing machine. The robot will be used for manipulation of the sample preparation and the manipulator take the sample preparation for processing.

  13. Innovative methods for inorganic sample preparation

    International Nuclear Information System (INIS)

    Essling, A.M.; Huff, E.A.; Graczyk, D.G.

    1992-04-01

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

  14. 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.

  15. Study of phosphors determination in biological samples

    International Nuclear Information System (INIS)

    Oliveira, Rosangela Magda de.

    1994-01-01

    In this paper, phosphors determination by neutron activation analysis in milk and bone samples was studied employing both instrumental and radiochemical separation methods. The analysis with radiochemistry separation consisted of the simultaneous irradiation of the samples and standards during 30 minutes, dissolution of the samples, hold back carrier, addition precipitation of phosphorus with ammonium phosphomolibdate (A.M.P.) and phosphorus-32 by counting by using Geiger-Mueller detector. The instrumental analysis consisted of the simultaneous irradiation of the samples and standards during 30 minutes, transfer of the samples into a counting planchet and measurement of the beta radiation emitted by phosphorus-32, after a suitable decay period. After the phosphorus analysis methods were established they were applied to both commercial milk and animal bone samples, and data obtained in the instrumental and radiochemical separation methods for each sample, were compared between themselves. In this work, it became possible to obtain analysis methods for phosphorus that can be applied independently of the sample quantity available, and the phosphorus content in the samples or interference that can be present in them. (author). 51 refs., 7 figs., 4 tabs

  16. Method and apparatus for sampling atmospheric mercury

    Science.gov (United States)

    Trujillo, Patricio E.; Campbell, Evan E.; Eutsler, Bernard C.

    1976-01-20

    A method of simultaneously sampling particulate mercury, organic mercurial vapors, and metallic mercury vapor in the working and occupational environment and determining the amount of mercury derived from each such source in the sampled air. A known volume of air is passed through a sampling tube containing a filter for particulate mercury collection, a first adsorber for the selective adsorption of organic mercurial vapors, and a second adsorber for the adsorption of metallic mercury vapor. Carbon black molecular sieves are particularly useful as the selective adsorber for organic mercurial vapors. The amount of mercury adsorbed or collected in each section of the sampling tube is readily quantitatively determined by flameless atomic absorption spectrophotometry.

  17. 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.

  18. Prompt Gamma Ray Analysis of Soil Samples

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, A.A.; Khiari, F.Z.; Haseeb, S.M.A.; Hussein, Tanvir; Khateeb-ur-Rehman [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Isab, A.H. [Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2015-07-01

    Neutron moderation effects were measured in bulk soil samples through prompt gamma ray measurements from water and benzene contaminated soil samples using 14 MeV neutron inelastic scattering. The prompt gamma rays were measured using a cylindrical 76 mm x 76 mm (diameter x height) LaBr{sub 3}:Ce detector. Since neutron moderation effects strongly depend upon hydrogen concentration of the sample, for comparison purposes, moderation effects were studied from samples containing different hydrogen concentrations. The soil samples with different hydrogen concentration were prepared by mixing soil with water as well as benzene in different weight proportions. Then, the effects of increasing water and benzene concentrations on the yields of hydrogen, carbon and silicon prompt gamma rays were measured. Moderation effects are more pronounced in soil samples mixed with water as compared to those from soil samples mixed with benzene. This is due to the fact that benzene contaminated soil samples have about 30% less hydrogen concentration by weight than the water contaminated soil samples. Results of the study will be presented. (authors)

  19. Unbiased Sampling and Meshing of Isosurfaces

    KAUST Repository

    Yan, Dongming

    2014-05-07

    In this paper, we present a new technique to generate unbiased samples on isosurfaces. An isosurface, F(x,y,z) = c , of a function, F , is implicitly defined by trilinear interpolation of background grid points. The key idea of our approach is that of treating the isosurface within a grid cell as a graph (height) function in one of the three coordinate axis directions, restricted to where the slope is not too high, and integrating / sampling from each of these three. We use this unbiased sampling algorithm for applications in Monte Carlo integration, Poisson-disk sampling, and isosurface meshing.

  20. Gaseous radiocarbon measurements of small samples

    International Nuclear Information System (INIS)

    Ruff, M.; Szidat, S.; Gaeggeler, H.W.; Suter, M.; Synal, H.-A.; Wacker, L.

    2010-01-01

    Radiocarbon dating by means of accelerator mass spectrometry (AMS) is a well-established method for samples containing carbon in the milligram range. However, the measurement of small samples containing less than 50 μg carbon often fails. It is difficult to graphitise these samples and the preparation is prone to contamination. To avoid graphitisation, a solution can be the direct measurement of carbon dioxide. The MICADAS, the smallest accelerator for radiocarbon dating in Zurich, is equipped with a hybrid Cs sputter ion source. It allows the measurement of both, graphite targets and gaseous CO 2 samples, without any rebuilding. This work presents experiences dealing with small samples containing 1-40 μg carbon. 500 unknown samples of different environmental research fields have been measured yet. Most of the samples were measured with the gas ion source. These data are compared with earlier measurements of small graphite samples. The performance of the two different techniques is discussed and main contributions to the blank determined. An analysis of blank and standard data measured within years allowed a quantification of the contamination, which was found to be of the order of 55 ng and 750 ng carbon (50 pMC) for the gaseous and the graphite samples, respectively. For quality control, a number of certified standards were measured using the gas ion source to demonstrate reliability of the data.