Introduction to SamplerCompare

Directory of Open Access Journals (Sweden)

Madeleine B. Thompson

2011-08-01

Full Text Available SamplerCompare is an R package for comparing the performance of Markov chain Monte Carlo (MCMC samplers. It samples from a collection of distributions with a collection of MCMC methods over a range of tuning parameters. Then, using log density evaluations per uncorrelated observation as a figure of merit, it generates a grid of plots showing the results of the simulation. It comes with a collection of predefined distributions and samplers and provides R and C interfaces for defining additional ones. It also provides the means to import simulation data generated by external systems. This document provides background on the package and demonstrates the basics of running simulations, visualizing results, and defining distributions and samplers in R.

Evaluation of passive samplers for the collection of dissolved organic matter in streams.

Science.gov (United States)

Warner, Daniel L; Oviedo-Vargas, Diana; Royer, Todd V

2015-01-01

Traditional sampling methods for dissolved organic matter (DOM) in streams limit opportunities for long-term studies due to time and cost constraints. Passive DOM samplers were constructed following a design proposed previously which utilizes diethylaminoethyl (DEAE) cellulose as a sampling medium, and they were deployed throughout a temperate stream network in Indiana. Two deployments of the passive samplers were conducted, during which grab samples were frequently collected for comparison. Differences in DOM quality between sites and sampling methods were assessed using several common optical analyses. The analyses revealed significant differences in optical properties between sampling methods, with the passive samplers preferentially collecting terrestrial, humic-like DOM. We assert that the differences in DOM composition from each sampling method were caused by preferential binding of complex humic compounds to the DEAE cellulose in the passive samplers. Nonetheless, the passive samplers may provide a cost-effective, integrated sample of DOM in situations where the bulk DOM pool is composed mainly of terrestrial, humic-like compounds.

Regulation of CCL2 expression by an upstream TALE homeodomain protein-binding site that synergizes with the site created by the A-2578G SNP.

Science.gov (United States)

Page, Stephen H; Wright, Edward K; Gama, Lucio; Clements, Janice E

2011-01-01

CC Chemokine Ligand 2 (CCL2) is a potent chemoattractant produced by macrophages and activated astrocytes during periods of inflammation within the central nervous system. Increased CCL2 expression is correlated with disease progression and severity, as observed in pulmonary tuberculosis, HCV-related liver disease, and HIV-associated dementia. The CCL2 distal promoter contains an A/G polymorphism at position -2578 and the homozygous -2578 G/G genotype is associated with increased CCL2 production and inflammation. However, the mechanisms that contribute to the phenotypic differences in CCL2 expression are poorly understood. We previously demonstrated that the -2578 G polymorphism creates a TALE homeodomain protein binding site (TALE binding site) for PREP1/PBX2 transcription factors. In this study, we identified the presence of an additional TALE binding site 22 bp upstream of the site created by the -2578 G polymorphism and demonstrated the synergistic effects of the two sites on the activation of the CCL2 promoter. Using chromatin immunoprecipitation (ChIP) assays, we demonstrated increased binding of the TALE proteins PREP1 and PBX2 to the -2578 G allele, and binding of IRF1 to both the A and G alleles. The presence of TALE binding sites that form inverted repeats within the -2578 G allele results in increased transcriptional activation of the CCL2 distal promoter while the presence of only the upstream TALE binding site within the -2578 A allele exerts repression of promoter activity.

The OPEnSampler: A Low-Cost, Low-Weight, Customizable and Modular Open Source 24-Unit Automatic Water Sampler

Science.gov (United States)

Nelke, M.; Selker, J. S.; Udell, C.

2017-12-01

Reliable automatic water samplers allow repetitive sampling of various water sources over long periods of time without requiring a researcher on site, reducing human error as well as the monetary and time costs of traveling to the field, particularly when the scale of the sample period is hours or days. The high fixed cost of buying a commercial sampler with little customizability can be a barrier to research requiring repetitive samples, such as the analysis of septic water pre- and post-treatment. DIY automatic samplers proposed in the past sacrifice maximum volume, customizability, or scope of applications, among other features, in exchange for a lower net cost. The purpose of this project was to develop a low-cost, highly customizable, robust water sampler that is capable of sampling many sources of water for various analytes. A lightweight aluminum-extrusion frame was designed and assembled, chosen for its mounting system, strength, and low cost. Water is drawn from two peristaltic pumps through silicone tubing and directed into 24 foil-lined 250mL bags using solenoid valves. A programmable Arduino Uno microcontroller connected to a circuit board communicates with a battery operated real-time clock, initiating sampling stages. Period and volume settings are programmable in-field by the user via serial commands. The OPEnSampler is an open design, allowing the user to decide what components to use and the modular theme of the frame allows fast mounting of new manufactured or 3D printed components. The 24-bag system weighs less than 10kg and the material cost is under $450. Up to 6L of sample water can be drawn at a rate of 100mL/minute in either direction. Faster flowrates are achieved by using more powerful peristaltic pumps. Future design changes could allow a greater maximum volume by filling the unused space with more containers and adding GSM communications to send real time status information.

Ebola virus RNA editing depends on the primary editing site sequence and an upstream secondary structure.

Directory of Open Access Journals (Sweden)

Masfique Mehedi

Full Text Available Ebolavirus (EBOV, the causative agent of a severe hemorrhagic fever and a biosafety level 4 pathogen, increases its genome coding capacity by producing multiple transcripts encoding for structural and nonstructural glycoproteins from a single gene. This is achieved through RNA editing, during which non-template adenosine residues are incorporated into the EBOV mRNAs at an editing site encoding for 7 adenosine residues. However, the mechanism of EBOV RNA editing is currently not understood. In this study, we report for the first time that minigenomes containing the glycoprotein gene editing site can undergo RNA editing, thereby eliminating the requirement for a biosafety level 4 laboratory to study EBOV RNA editing. Using a newly developed dual-reporter minigenome, we have characterized the mechanism of EBOV RNA editing, and have identified cis-acting sequences that are required for editing, located between 9 nt upstream and 9 nt downstream of the editing site. Moreover, we show that a secondary structure in the upstream cis-acting sequence plays an important role in RNA editing. EBOV RNA editing is glycoprotein gene-specific, as a stretch encoding for 7 adenosine residues located in the viral polymerase gene did not serve as an editing site, most likely due to an absence of the necessary cis-acting sequences. Finally, the EBOV protein VP30 was identified as a trans-acting factor for RNA editing, constituting a novel function for this protein. Overall, our results provide novel insights into the RNA editing mechanism of EBOV, further understanding of which might result in novel intervention strategies against this viral pathogen.

Ebola virus RNA editing depends on the primary editing site sequence and an upstream secondary structure.

Science.gov (United States)

Mehedi, Masfique; Hoenen, Thomas; Robertson, Shelly; Ricklefs, Stacy; Dolan, Michael A; Taylor, Travis; Falzarano, Darryl; Ebihara, Hideki; Porcella, Stephen F; Feldmann, Heinz

2013-01-01

Ebolavirus (EBOV), the causative agent of a severe hemorrhagic fever and a biosafety level 4 pathogen, increases its genome coding capacity by producing multiple transcripts encoding for structural and nonstructural glycoproteins from a single gene. This is achieved through RNA editing, during which non-template adenosine residues are incorporated into the EBOV mRNAs at an editing site encoding for 7 adenosine residues. However, the mechanism of EBOV RNA editing is currently not understood. In this study, we report for the first time that minigenomes containing the glycoprotein gene editing site can undergo RNA editing, thereby eliminating the requirement for a biosafety level 4 laboratory to study EBOV RNA editing. Using a newly developed dual-reporter minigenome, we have characterized the mechanism of EBOV RNA editing, and have identified cis-acting sequences that are required for editing, located between 9 nt upstream and 9 nt downstream of the editing site. Moreover, we show that a secondary structure in the upstream cis-acting sequence plays an important role in RNA editing. EBOV RNA editing is glycoprotein gene-specific, as a stretch encoding for 7 adenosine residues located in the viral polymerase gene did not serve as an editing site, most likely due to an absence of the necessary cis-acting sequences. Finally, the EBOV protein VP30 was identified as a trans-acting factor for RNA editing, constituting a novel function for this protein. Overall, our results provide novel insights into the RNA editing mechanism of EBOV, further understanding of which might result in novel intervention strategies against this viral pathogen.

7 CFR 61.30 - Examination of sampler.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Examination of sampler. 61.30 Section 61.30... Cottonseed Samplers § 61.30 Examination of sampler. Each applicant for a license as a sampler and each... examination or test to show his ability properly to perform the duties for which he is applying for a license...

Remote Sampler Demonstration Isolok Configuration Test

International Nuclear Information System (INIS)

Kelly, Steve E.

2016-01-01

The accuracy and precision of a new Isolok sampler configuration was evaluated using a recirculation flow loop. The evaluation was performed using two slurry simulants of Hanford high-level tank waste. Through testing, the capability of the Isolok sampler was evaluated. Sample concentrations were compared to reference samples that were simultaneously collected by a two-stage Vezin sampler. The capability of the Isolok sampler to collect samples that accurately reflect the contents in the test loop improved – biases between the Isolok and Vezin samples were greatly reduce for fast settling particles.

Remote Sampler Demonstration Isolok Configuration Test

Energy Technology Data Exchange (ETDEWEB)

Kelly, Steve E. [Washington River Protection Solutions, LLC, Richland, WA (United States)

2016-06-08

The accuracy and precision of a new Isolok sampler configuration was evaluated using a recirculation flow loop. The evaluation was performed using two slurry simulants of Hanford high-level tank waste. Through testing, the capability of the Isolok sampler was evaluated. Sample concentrations were compared to reference samples that were simultaneously collected by a two-stage Vezin sampler. The capability of the Isolok sampler to collect samples that accurately reflect the contents in the test loop improved – biases between the Isolok and Vezin samples were greatly reduce for fast settling particles.

Comparative evaluation of three impactor samplers for measuring airborne bacteria and fungi concentrations.

Science.gov (United States)

Méheust, Delphine; Gangneux, Jean-Pierre; Cann, Pierre Le

2013-01-01

Portable microbial samplers are useful for detecting microorganisms in the air. However, limited data are available on their performance when sampling airborne biological agents in a routine practice. We compared bacterial and fungal concentrations obtained in field conditions using three impactor samplers with different designs (AES Chemunex Sampl'Air, bioMérieux Air Ideal, and Sartorius AirPort MD8/BACTair). The linearity of mold collection was tested in the range of 100 L to 1000 L, and all the devices had a correlation coefficient higher than 0.95. For optimal comparison of the samplers, we performed experiments in different hospital rooms with varying levels of air biocontamination. Each sampling procedure was repeated to assess reproducibility. No significant difference between the samplers was observed for the mold concentrations on Sabouraud agar, whereas Sampl'Air collected significantly more bacteria on tryptic soy agar than Air Ideal or BACTair at one of the sites. Impactor location in the room was nevertheless associated with the variability observed with the three samplers at the highest microbial concentration levels. On the basis of their performance, autonomy and simplicity of use, these three impactors are suitable for routine indoor evaluation of microbial air contamination.

A passive air sampler for characterizing the vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air.

Science.gov (United States)

Zhang, Yuzhong; Deng, Shuxing; Liu, Yanan; Shen, Guofeng; Li, Xiqing; Cao, Jun; Wang, Xilong; Reid, Brian; Tao, Shu

2011-03-01

Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAH(LMW4)) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAH(LMW4) within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. Copyright © 2010 Elsevier Ltd. All rights reserved.

Assessment of benthic macroinvertebrates at Nile tilapia production using artificial substrate samplers

Directory of Open Access Journals (Sweden)

M. S. G. Moura e Silva

Full Text Available Abstract Biomonitoring is a cheap and effective tool for evaluation of water quality, and infer on the balance of aquatic ecosystems. The benthic macroinvertebrates are bioindicators sensitive to environmental changes, and can assist in detecting and preventing impacts such as organic enrichment and imbalance in the food chain. We compared the structure of benthic communities on artificial substrate samplers located in places near and far from net cages for production of Nile tilapia (Oreochromis niloticus. Samplers were manufactured with nylon net, using substrates such as crushed stone, gravel, loofah and cattail leaves. Samples were collected after 30 days of colonization, rinsed and then the specimens were identified and quantified. The following metrics were calculated: richness of Operational Taxonomic Units, Margalef richness, abundance of individuals, Shannon index and evenness index. The macrobenthic community structure was strongly modified according to the proximity of the net cages. Metrics showed significant differences (p < 0.05 between near and distant sites, for both periods (dry and rainy seasons. The position of the samplers significantly affected the structure of macroinvertebrate community, as near sites showed higher values for the community metrics, such as richness and diversity. Near sites presented a larger number of individuals, observed both in the dry and rainy seasons, with a predominance of Chironomidae (Diptera in the dry season and Tubificidae (Oligochaeta in the rainy season.

Sequence motif upstream of the Hendra virus fusion protein cleavage site is not sufficient to promote efficient proteolytic processing

International Nuclear Information System (INIS)

Craft, Willie Warren; Dutch, Rebecca Ellis

2005-01-01

The Hendra virus fusion (HeV F) protein is synthesized as a precursor, F 0 , and proteolytically cleaved into the mature F 1 and F 2 heterodimer, following an HDLVDGVK 109 motif. This cleavage event is required for fusogenic activity. To determine the amino acid requirements for processing of the HeV F protein, we constructed multiple mutants. Individual and simultaneous alanine substitutions of the eight residues immediately upstream of the cleavage site did not eliminate processing. A chimeric SV5 F protein in which the furin site was substituted for the VDGVK 109 motif of the HeV F protein was not processed but was expressed on the cell surface. Another chimeric SV5 F protein containing the HDLVDGVK 109 motif of the HeV F protein underwent partial cleavage. These data indicate that the upstream region can play a role in protease recognition, but is neither absolutely required nor sufficient for efficient processing of the HeV F protein

A passive air sampler for characterizing the vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air

International Nuclear Information System (INIS)

Zhang Yuzhong; Deng Shuxing; Liu Yanan; Shen Guofeng; Li Xiqing; Cao Jun; Wang Xilong; Reid, Brian; Tao Shu

2011-01-01

Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAH LMW4 ) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAH LMW4 within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. - Research highlights: → Design, field test and calibration of the novel passive air sampler, PAS-V-I. → Vertical concentration gradients of PAH LMW4 within a thin layer close to soil. → Comparison of results between PAS-V-I measurement and fugacity approach. → Potential application of PAS-V-I and further modifications. - A novel passive sampling device was developed and tested for measuring vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air.

Functional groups of macro-benthos of selected sites of upstream of Hron River and Hnilec River

International Nuclear Information System (INIS)

Rufusova, A.

2011-01-01

The author used six functional groups of macro-benthos based on 'species traits', which are indicated with the Greek letters α to ζ. In the work authors applied this method to the macroinvertebrate communities of selected sites of upstream of the Hron River and the Hnilec River. The method appropriately captured increasing gradient of anthropogenic changes in the direction of the river continuum. Although the method was used for Slovak rivers for the first time, it seems to be promising for use in the future. (author)

Design of dry sand soil stratified sampler

Science.gov (United States)

Li, Erkang; Chen, Wei; Feng, Xiao; Liao, Hongbo; Liang, Xiaodong

2018-04-01

This paper presents a design of a stratified sampler for dry sand soil, which can be used for stratified sampling of loose sand under certain conditions. Our group designed the mechanical structure of a portable, single - person, dry sandy soil stratified sampler. We have set up a mathematical model for the sampler. It lays the foundation for further development of design research.

Environmental monitoring of tritium in air with passive diffusion samplers

International Nuclear Information System (INIS)

Wood, M.J.; Workman, W.J.G.

1992-01-01

This paper reports on a field trail in which outdoor air was sampled with an active reference sampler and several passive HTO-in-air samplers simultaneously carried out at Chalk River Laboratories. Both passive and active samplers were changed on an approximately monthly schedule from 1990 September 2 to 1991 April 18. Average temperatures for the sampling intervals ranged from -8.06 degrees C to +15.5 degrees C and HTO-in-air concentrations measured by the active sampler were typically 10 Bq/m 3 . A total of 1290 passive HTO-in-air sampler measurements were made during the seven sampling intervals. The passive samplers used for the field trial were prepared with either tritium-free water or a solution of 50% tritium-free water and 50% ethylene glycol. As expected, the samplers prepared with the water-glycol solution performed more consistently than the samplers prepared with water only. Good agreement between passive and active sampler measurements was observed throughout the field trial

Performance improvements on passive activated charcoal 222Rn samplers

International Nuclear Information System (INIS)

Wei Suxia

1996-01-01

Improvements have been made on passive activated charcoal 222 Rn samplers with sintered metal filters. Based on the samplers of good adaptability to temperature and humidity developed before, better charcoal was selected to further improve their performance in radon absorption ability and moisture-resistance. And charcoal quantity in samplers was strictly controlled. The integration time constant of the improved samplers was about 4.3 days. As the sampler was combined with gamma spectrometer to measure radon concentration, the calibration factor was 0.518 min -1 ·Bq -1 ·m 3 for samplers of 7 days exposure time, and the minimum detectable concentration 0.28 Bq·m -3 if counting time for both background and sample is 1000 minutes. The improved samplers are suited to accurately determine the indoor and outdoor average radon concentration under conditions of great variation in temperature and humidity

Pesticide impact on aquatic invertebrates identified with Chemcatcher® passive samplers and the SPEAR(pesticides) index.

Science.gov (United States)

Münze, Ronald; Orlinskiy, Polina; Gunold, Roman; Paschke, Albrecht; Kaske, Oliver; Beketov, Mikhail A; Hundt, Matthias; Bauer, Coretta; Schüürmann, Gerrit; Möder, Monika; Liess, Matthias

2015-12-15

Pesticides negatively affect biodiversity and ecosystem function in aquatic environments. In the present study, we investigated the effects of pesticides on stream macroinvertebrates at 19 sites in a rural area dominated by forest cover and arable land in Central Germany. Pesticide exposure was quantified with Chemcatcher® passive samplers equipped with a diffusion-limiting membrane. Ecological effects on macroinvertebrate communities and on the ecosystem function detritus breakdown were identified using the indicator system SPEARpesticides and the leaf litter degradation rates, respectively. A decrease in the abundance of pesticide-vulnerable taxa and a reduction in leaf litter decomposition rates were observed at sites contaminated with the banned insecticide Carbofuran (Toxic Units≥-2.8), confirming the effect thresholds from previous studies. The results show that Chemcatcher® passive samplers with a diffusion-limiting membrane reliably detect ecologically relevant pesticide pollution, and we suggest Chemcatcher® passive samplers and SPEARpesticides as a promising combination to assess pesticide exposure and effects in rivers and streams. Copyright © 2015 Elsevier B.V. All rights reserved.

Photodegradation of polyaromatic hydrocarbons in passive air samplers: Field testing different deployment chambers

International Nuclear Information System (INIS)

Bartkow, Michael E.; Kennedy, Karen E.; Huckins, James N.; Holling, Neil; Komarova, Tatiana; Mueller, Jochen F.

2006-01-01

Semi-permeable membrane devices (SPMDs) were loaded with deuterated anthracene and pyrene as performance reference compounds (PRCs) and deployed at a test site in four different chambers (open and closed box chamber, bowl chamber and cage chamber) for 29 days. The losses of PRCs and the uptake of polyaromatic hydrocarbons (PAHs) from the ambient air were quantified. UV-B levels measured in each deployment chamber indicated that SPMDs would be exposed to the most UV-B in the cage chamber and open box chamber. Significantly less PAHs were quantified in SPMDs deployed in the cage chamber and open box chamber compared to samplers from the other two chambers, suggesting that photodegradation of PAHs had occurred. The loss of PRCs confirmed these results but also showed that photodegradation was occurring in the closed box chamber. The bowl chamber appears to provide the best protection from the influence of direct photodegradation. - Photodegradation/loss of PAHs occurs from passive air samplers (SPMDs) deployed in various sampler chambers

Characterization of the GENT PM10 sampler. Appendix 18

International Nuclear Information System (INIS)

Hopke, Philip K.; Xie Ying; Raunemaa, Taisto; Biegalski, Steven; Landsberger, Sheldon

1995-01-01

An integral part of the Co-ordinated Research Programme: Applied Research on Air Pollution using Nuclear-Related Analytical Techniques is the PM 10 sampler that was designed by Dr. W. Maenhaut of the University of Gent. Each participant was provided with such a sampler so that comparable samples will be obtained by each of the participating groups. Thus, in order to understand the characteristics of this sampler, we have undertaken several characterization studies in which we have examine the aerodynamic collection characteristics of the impactor inlet and the reproducibility of the sample mass collection. The sampler does provide a collection efficiency that follows the guidelines for a PM 10 sampler. Comparing one of the original samplers built at the University of Gent with a unit built from the same plans at Clarkson University showed good reproducibility in mass collection. (author)

Statistical analysis of the DWPF prototypic sampler

International Nuclear Information System (INIS)

Postles, R.L.; Reeve, C.P.; Jenkins, W.J.; Bickford, D.F.

1991-01-01

The DWPF process will be controlled using assay measurements on samples of feed slurry. These slurries are radioactive, and thus will be sampled remotely. A Hydraguard trademark pump-driven sampler system will be used as the remote sampling device. A prototype Hydraguard trademark sampler has been studied in a full-scale mock-up of a DWPF process vessel. Two issues were of dominant interest: (1) what accuracy and precision can be provided by such a pump-driven sampler in the face of the slurry rheology; and, if the Hydraguard trademark sample accurately represents the slurry in its local area, (2) is the slurry homogeneous enough throughout for it to represent the entire vessel? To determine Hydraguard trademark Accuracy, a Grab Sampler of simpler mechanism was used as reference. This (Low) Grab Sampler was located as near to the intake port of the Hydraguard trademark as could be arranged. To determine Homogeneity, a second (High) Grab Sampler was located above the first. The data necessary to these determinations comes from the measurement system, so its important variables also affect the results. Thus, the design of the test involved not just Sampling variables, but also some of the Measurement variables as well. However, the main concern was the Sampler and not the Measurement System, so the test design included only such measurement variables as could not be circumvented (Vials, Dissolution Method, and Aliquoting). The test was executed by, or under the direct oversight of, expert technologists. It thus did not explore the many important particulars of ''routine'' plant operations (such as Remote Sample Preparation or Laboratory Shift Operation)

The influence of geometry and draught shields on the performance of passive samplers

NARCIS (Netherlands)

Hofschreuder, P.; Meulen, van der W.; Heeres, P.; Slanina, J.

1999-01-01

Passive samplers provide an excellent opportunity to perform indicative measurements or establish a dense network of measuring sites. A drawback compared with conventional active measuring methods is the larger spread of results. This variation can, to a large extent, be attributed to the influence

Passive samplers and community science in regional air quality measurement, education and communication

International Nuclear Information System (INIS)

DeForest Hauser, Cindy; Buckley, Alexandra; Porter, Juliana

2015-01-01

Charlotte, in Mecklenburg County, North Carolina, was ranked in the top ten cities with the worst air quality for ozone in the United States by the American Lung Association from 2009 to 2011. Nearby counties that may experience similar air quality do not have state or county monitors. This study utilized NO x and ozone Ogawa passive samplers and community scientists to monitor air quality in five counties surrounding Charlotte and increase public engagement in air quality issues. Community scientists deployed samplers weekly at a residential site within each county. Samples were analyzed using spectrophotometry and ion chromatography. Elevated NO x concentrations were observed in four of the five counties relative to those with existing monitors. Ozone concentrations showed little county to county variation, except Iredell and Cabarrus which had higher concentrations than Rowan. Community involvement in this work led to an increase in local dissemination of the results, thus increasing air quality awareness. - Highlights: • NO x concentrations in four adjacent counties were higher than the Mecklenburg site. • Ozone concentrations showed little county to county variation. • Passive samplers and community science can extend the air quality monitoring network. • Community science increases community awareness of air quality issues. - Regional community air quality monitoring is important in educating communities about air quality science issues that can impact personal health and behavior

Functional design criteria for the retained gas sampler system

International Nuclear Information System (INIS)

Wootan, D.W.

1995-01-01

A Retained Gas Sampler System (RGSS) is being developed to capture and analyze waste samples from Hanford Flammable Gas Watch List Tanks to determine both the quantity and composition of gases retained in the waste. The RGSS consists of three main components: the Sampler, Extractor, and Extruder. This report describes the functional criteria for the design of the RGSS components. The RGSS Sampler is based on the WHC Universal Sampler design with modifications to eliminate gas leakage. The primary function of the Sampler is to capture a representative waste sample from a tank and transport the sample with minimal loss of gas content from the tank to the laboratory. The function of the Extruder is to transfer the waste sample from the Sampler to the Extractor. The function of the Extractor is to separate the gases from the liquids and solids, measure the relative volume of gas to determine the void fraction, and remove and analyze the gas constituents

Development of polyurethane-based passive samplers for ambient monitoring of urban-use insecticides in water.

Science.gov (United States)

Liao, Chunyang; Richards, Jaben; Taylor, Allison R; Gan, Jay

2017-12-01

Widespread use of insecticides for the control of urban pests such as ants, termites, and spiders has resulted in contamination and toxicity in urban aquatic ecosystems in different regions of the world. Passive samplers are a convenient and integrative tool for in situ monitoring of trace contaminants in surface water. However, the performance of a passive sampler depends closely on its affinity for the target analytes, making passive samplers highly specific to the types of contaminants being monitored. The goal of this study was to develop a passive sampler compatible with a wide range of insecticides, including the strongly hydrophobic pyrethroids and the weakly hydrophobic fipronil and organophosphates. Of six candidate polymeric thin films, polyurethane film (PU) was identified to be the best at enriching the test compounds. The inclusion of stable isotope labeled analogs as performance reference compounds (PRCs) further allowed the use of PU film for pyrethroids under non-equilibrium conditions. The PU sampler was tested in a large aquarium with circulatory water flow, and also deployed at multiple sites in surface streams in southern California. The concentrations of pesticides derived from the PU sampler ranged from 0.5 to 18.5 ng/L, which were generally lower than the total chemical concentration measured by grab samples, suggesting that suspended particles and dissolved organic matter in water rendered them less available. The influence of suspended particles and dissolved organic matter on bioavailability was more pronounced for pyrethroids than for fipronils. The results show that the developed PU film sampler, when coupled with PRCs, may be used for rapid and sensitive in-situ monitoring of a wide range of insecticides in surface water. Copyright © 2017 Elsevier Ltd. All rights reserved.

A radon progeny sampler for the determination of effective dose

Energy Technology Data Exchange (ETDEWEB)

Solomon, S.B. [Australian Radiation Laboratory, Victoria (Australia)

1997-12-01

The design and simulated performance is described of a two-stage sampler (HE-Sampler) for {sup 222}Rn progeny. This HE-Sampler has a collection efficiency optimised to match the particle size dependency of the radon progeny dose conversion factor (DCF), derived from the latest Respiratory Tract Model of the International Commission on Radiological Protection, as implemented in the computer code RADEP. The He-Sampler comprises a wire screen pre-separator, matched to the nasal deposition, and a wire screen collector, matched to the respiratory tract collection. This HE-Sampler allows for the estimation of the radiation dose from the inhalation of {sup 222}Rn progeny, derived from two concurrent alpha particle activity measurements, one on the HE-Sampler screen collector and one on a reference filter sample. As a first approximation, the DCF is proportional to the collected fraction. The HE-Sampler response was simulated for a range of radon progeny size distributions to determine the error in the estimated DCF values. The simulation results show that the HE-Sampler is relatively insensitive to variations in sampling rate and in the screen parameters, particularly for environmental exposure. (Author).

Particle capturing performance of South African non corrosive samplers

CSIR Research Space (South Africa)

Pretorius, C

2010-05-01

Full Text Available eq ue nc y D50 D90 © CSIR 2007 www.csir.co.za Particle size distribution of sampled filters taken in three platinum mines PSA results according to mine 0 2 4 6 8 10 12 14 16 X-Samplers Y-Samplers X-Samplers Y...

Passive sampler for dissolved organic matter in freshwater environments.

Science.gov (United States)

Lam, Buuan; Simpson, André J

2006-12-15

A passive sampler for the isolation of dissolved organic matter (DOM) from freshwater environments is described. The sampler consists of a molecular weight selective membrane (1000 kDa) and an anion exchange resin (diethylaminoethylcellulose (DEAE-cellulose)). NMR indicates the samplers isolate DOM that is nearly indistinguishable from that isolated using the batch DEAE-cellulose procedure. In a comparative study DOM isolated from Lake Ontario cost approximately 0.30 dollars/mg to isolate using the passive samplers while DOM isolated using the traditional batch procedure cost approximately 8-10 dollars/mg. The samplers have been shown to be effective in a range of freshwater environments including a large inland lake (Lake Ontario), fast flowing tributary, and wetland. Large amounts (gram quantities of DOM) can be easily isolated by increasing the size or number of samplers deployed. Samplers are easy to construct, negate the need for pressure filtering, and also permit a range of temporal and spatial experiments that would be very difficult or impossible to perform using conventional approaches. For example, DOM can be monitored on a regular basis at numerous different locations, or samplers could be set at different depths in large lakes. Furthermore, they could potentially be deployed into hard to reach environments such as wells, groundwater aquifers, etc., and as they are easy to use, they can be mailed to colleagues or included with expeditions going to difficult to reach places such as the Arctic and Antarctic.

Particle-capturing performance of South African non-corrosive samplers

CSIR Research Space (South Africa)

Pretorius, CJ

2011-10-01

Full Text Available analysis (PSA) could be carried out. The duration of the sampling was established at ? 30 seconds, so the mass of dust collected per sample ranged from 1 to 2 mg. The flow rates for each sampler were specified by the suppliers. For the X... chain to eliminate pulsation in the air flow. The pressure loss due to air flow resistance was measured with a digital micro manometer for each sampler with 2.2 L/min passing through the sampler (2.5 L/min for the aluminium samplers). PSA...

EVALUATION OF MEMBRANE TYPE FOR USE IN DIFFUSION SAMPLERS TO MONITOR GROUND WATER QUALITY

Science.gov (United States)

The Discrete Multi-Level Sampler (DMLS®) system has proven to be a useful tool for obtaining discrete interval contaminant concentrations at hazardous waste sites. The DMLS® utilizes dialysis cells, which consist of a polypropylene vial, covered on both ends by a permeable membr...

Environmental HTO/HT sampler development

International Nuclear Information System (INIS)

Workman, W.J.G.; Brown, R.M.; Wood, M.J.

1992-12-01

Tests of retention by several drying agents of HTO from an air stream containing HT have been performed. Two batches of Molecular Sieve (MS) 4A retained up to 1.3% of HT passed through them in contrast to material tested in 1986, when retention was -4 . Retention of 10 -5 to 10 -6 was observed for DRIERITE (anhydrous calcium sulphate) and Silica Gel. DRIERITE is preferred over Silica Gel as a desiccant in an air sampler for environmental HTO/HT, because it is much easier to decontaminate for reuse. An improved air sampler has been designed, 2 units constructed and components procured for 3 more. The air sampler may be line or battery operated, accommodates up to four 120 g drier or oxidizer traps, and will pump up to 4 L/min for up to 24 hours on battery power. It is build into a rugged aluminum case and weighs approximately 11 kg overall, facilitating deployment in the field

Environmental HTO/HT sampler development

International Nuclear Information System (INIS)

Workman, W.J.G.; Brown, R.M.; Wood, M.J.

1994-01-01

Tests of retention by several drying agents of HTO from an air stream containing HT have been performed. Two batches of Molecular Sieve (MS) 4A retained up to 1.3% of HT passed through them, in contrast to material tested in 1986, when retention was -4 . Retention of 10 -5 to 10 -6 was observed for DRIERITE (anhydrous calcium sulphate) and Silica Gel. DRIERITE is preferred over Silica Gel as a desiccant in an air sampler for environmental HTO/HT, because it is much easier to decontaminate for reuse. An improved air sampler has been designed, 2 units constructed and components procured for 3 more. The air sampler may be line or battery operated, accommodates up to four 120 g drier or oxidizer traps, and will pump up to 4 L/min for up to 24 hours on battery power. It is built into a rugged aluminum case and weighs approximately 11 kg overall, facilitating deployment in the field. (author). 5 refs., 2 tabs., 4 figs

Pinus nigra and Pinus pinaster needles as passive samplers of polycyclic aromatic hydrocarbons

International Nuclear Information System (INIS)

Piccardo, Maria Teresa; Pala, Mauro; Bonaccurso, Bruna; Stella, Anna; Redaelli, Anna; Paola, Gaudenzio; Valerio, Federico

2005-01-01

Nine polycyclic aromatic hydrocarbons (PAHs) were analysed in pine needles of different ages (from 6 to 30 months) collected from two species, Pinus nigra and Pinus pinaster, in seven sites located along a transect from a suburban to a rural area of Genoa (Italy). In all sites and for both species, concentrations of more volatile PAHs (phenanthrene, anthracene, fluoranthene, pyrene) were higher than those for other less volatile PAHs, which are preferentially sorbed to airborne particulates (benzo[a]anthracene, chrysene, benzofluoranthenes, benzo[a]pyrene). Concentrations of total PAHs found in P. nigra in the rural sites were, on the average, 2.3 times higher than those in P. pinaster growing nearby. In both pine species, concentrations of volatile PAHs increased according to needle age. Annual trends of other PAHs were more variable, with a general decrease in older needles. P. pinaster needles are shown to be more reliable passive samplers, since they are more resistant to plant diseases, and considerable variation in PAH concentration was observed in P. nigra needles with moulds and fungi. - The suitability of the pine needles as passive air samplers for persistent trace organics is demonstrated

Pinus nigra and Pinus pinaster needles as passive samplers of polycyclic aromatic hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Piccardo, Maria Teresa [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy)]. E-mail: chimamb@istge.it; Pala, Mauro [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy); Bonaccurso, Bruna [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy); Stella, Anna [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy); Redaelli, Anna [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy); Paola, Gaudenzio [Botany Department, Genoa University, C.so Dogali 1 canc., 16136 Genova (Italy); Valerio, Federico [Environmental Chemistry Laboratory, National Cancer Research Institute, Genova. L.go Rosanna Benzi n. 10, 16132 Genova (Italy)

2005-01-01

Nine polycyclic aromatic hydrocarbons (PAHs) were analysed in pine needles of different ages (from 6 to 30 months) collected from two species, Pinus nigra and Pinus pinaster, in seven sites located along a transect from a suburban to a rural area of Genoa (Italy). In all sites and for both species, concentrations of more volatile PAHs (phenanthrene, anthracene, fluoranthene, pyrene) were higher than those for other less volatile PAHs, which are preferentially sorbed to airborne particulates (benzo[a]anthracene, chrysene, benzofluoranthenes, benzo[a]pyrene). Concentrations of total PAHs found in P. nigra in the rural sites were, on the average, 2.3 times higher than those in P. pinaster growing nearby. In both pine species, concentrations of volatile PAHs increased according to needle age. Annual trends of other PAHs were more variable, with a general decrease in older needles. P. pinaster needles are shown to be more reliable passive samplers, since they are more resistant to plant diseases, and considerable variation in PAH concentration was observed in P. nigra needles with moulds and fungi. - The suitability of the pine needles as passive air samplers for persistent trace organics is demonstrated.

Comparison of the sampling rates and partitioning behaviour of polar and non-polar contaminants in the polar organic chemical integrative sampler and a monophasic mixed polymer sampler for application as an equilibrium passive sampler.

Science.gov (United States)

Jeong, Yoonah; Schäffer, Andreas; Smith, Kilian

2018-06-15

In this work, Oasis HLB® beads were embedded in a silicone matrix to make a single phase passive sampler with a higher affinity for polar and ionisable compounds than silicone alone. The applicability of this mixed polymer sampler (MPS) was investigated for 34 aquatic contaminants (log K OW -0.03 to 6.26) in batch experiments. The influence of flow was investigated by comparing uptake under static and stirred conditions. The sampler characteristics of the MPS was assessed in terms of sampling rates (R S ) and sampler-water partition coefficients (K SW ), and these were compared to those of the polar organic chemical integrative sampler (POCIS) as a reference kinetic passive sampler. The MPS was characterized as an equilibrium sampler for both polar and non-polar compounds, with faster uptake rates and a shorter time to reach equilibrium than the POCIS. Water flow rate impacted sampling rates by up to a factor of 12 when comparing static and stirred conditions. In addition, the relative accumulation of compounds in the polyethersulfone (PES) membranes versus the inner Oasis HLB sorbent was compared for the POCIS, and ranged from <1% to 83% depending on the analyte properties. This is indicative of a potentially significant lag-phase for less polar compounds within POCIS. The findings of this study can be used to quantitatively describe the partitioning and kinetic behaviour of MPS and POCIS for a range of aquatic organic contaminants for application in field sampling. Copyright © 2018 Elsevier B.V. All rights reserved.

A Passive Diffusion Sampler for HT- and HTO-in-Air

International Nuclear Information System (INIS)

Surette, R.A.; Nunes, J.C.

2005-01-01

Fusion research and tritium removal facilities potentially handle large inventories of tritium gas (HT). If any HT is released into the workplace, a fraction may be converted to tritiated water vapour (HTO). A convenient method to determine the activity concentration of each species is necessary to assess the potential hazard since the radiological hazard of HTO is more than 10 4 that due to HT. Passive samplers for measuring tritiated water vapour (HTO) have been shown to be suitable for use indoors and outdoors. These simple samplers consist of a standard 20-mL liquid scintillation vial with a diffusion orifice that determines the sampling rate.The total tritium samplers described herein are passive or diffusion samplers that contain a small amount of AECL-proprietary wet-proofed catalyst fixed to the underside of the sampling heads to allow conversion of the HT to HTO that is subsequently collected in the sink, (HTO), in the bottom of the sampler. After an appropriate sampling time, liquid scintillation cocktail is added to the vial and the activity collected determined by liquid scintillation analysis. When used in conjunction with the conventional HTO passive sampler the difference between the total and HTO samplers can be used to determine the HT fraction ((HT+HTO) - HTO HT). The sampling rates for the modified diffusion sampler were measured to be 4.6 and 8.1 L/d for HTO and HT, respectively. For a fifteen-minute sampling period, passive samplers can be used to measure tritium activity concentrations from 37 kBq/m 3 to 115 MBq/m 3

Sampler collection gadget for epilithic diatoms.

Science.gov (United States)

Salomoni, S E; Torgan, L C; Rocha, O

2007-11-01

This work present a new gadget for sampling epilithic diatoms from both lentic and lotic enviroments. The sampler consists of a polystyrene cylinder, left to float on the surface of the water, to which stone substrates are attached. This epilithic diatom sampler (EDS) can be used to detect spatial and temporal richness and density variation in the study of the diatom community, as well as in water quality monitoring.

50 CFR 697.12 - At-sea sea sampler/observer coverage.

Science.gov (United States)

2010-10-01

... sampler/observer access to and use of the vessel's communications equipment and personnel upon request for...) Allow the sea sampler/observer to inspect and copy the vessel's log, communications log, and records... must: (1) Notify the sea sampler/observer of any sea turtles, marine mammals, or other specimens taken...

Automated particulate sampler field test model operations guide

Energy Technology Data Exchange (ETDEWEB)

Bowyer, S.M.; Miley, H.S.

1996-10-01

The Automated Particulate Sampler Field Test Model Operations Guide is a collection of documents which provides a complete picture of the Automated Particulate Sampler (APS) and the Field Test in which it was evaluated. The Pacific Northwest National Laboratory (PNNL) Automated Particulate Sampler was developed for the purpose of radionuclide particulate monitoring for use under the Comprehensive Test Ban Treaty (CTBT). Its design was directed by anticipated requirements of small size, low power consumption, low noise level, fully automatic operation, and most predominantly the sensitivity requirements of the Conference on Disarmament Working Paper 224 (CDWP224). This guide is intended to serve as both a reference document for the APS and to provide detailed instructions on how to operate the sampler. This document provides a complete description of the APS Field Test Model and all the activity related to its evaluation and progression.

Sampler collection gadget for epilithic diatoms

Directory of Open Access Journals (Sweden)

SE. Salomoni

Full Text Available This work present a new gadget for sampling epilithic diatoms from both lentic and lotic enviroments. The sampler consists of a polystyrene cylinder, left to float on the surface of the water, to which stone substrates are attached. This epilithic diatom sampler (EDS can be used to detect spatial and temporal richness and density variation in the study of the diatom community, as well as in water quality monitoring.

Coalescent genealogy samplers: windows into population history.

Science.gov (United States)

Kuhner, Mary K

2009-02-01

Coalescent genealogy samplers attempt to estimate past qualities of a population, such as its size, growth rate, patterns of gene flow or time of divergence from another population, based on samples of molecular data. Genealogy samplers are increasingly popular because of their potential to disentangle complex population histories. In the last decade they have been widely applied to systems ranging from humans to viruses. Findings include detection of unexpected reproductive inequality in fish, new estimates of historical whale abundance, exoneration of humans for the prehistoric decline of bison and inference of a selective sweep on the human Y chromosome. This review summarizes available genealogy-sampler software, including data requirements and limitations on the use of each program.

Sorbent Film-Coated Passive Samplers for Explosives Vapour Detection Part A: Materials Optimisation and Integration with Analytical Technologies.

Science.gov (United States)

McEneff, Gillian L; Murphy, Bronagh; Webb, Tony; Wood, Dan; Irlam, Rachel; Mills, Jim; Green, David; Barron, Leon P

2018-04-11

A new thin-film passive sampler is presented as a low resource dependent and discrete continuous monitoring solution for explosives-related vapours. Using 15 mid-high vapour pressure explosives-related compounds as probes, combinations of four thermally stable substrates and six film-based sorbents were evaluated. Meta-aramid and phenylene oxide-based materials showed the best recoveries from small voids (~70%). Analysis was performed using liquid chromatography-high resolution accurate mass spectrometry which also enabled tentative identification of new targets from the acquired data. Preliminary uptake kinetics experiments revealed plateau concentrations on the device were reached between 3-5 days. Compounds used in improvised explosive devices, such as triacetone triperoxide, were detected within 1 hour and were stably retained by the sampler for up to 7 days. Sampler performance was consistent for 22 months after manufacture. Lastly, its direct integration with currently in-service explosives screening equipment including ion mobility spectrometry and thermal desorption mass spectrometry is presented. Following exposure to several open environments and targeted interferences, sampler performance was subsequently assessed and potential interferences identified. High-security building and area monitoring for concealed explosives using such cost-effective and discrete passive samplers can add extra assurance to search routines while minimising any additional burden on personnel or everyday site operation.

Enhanced surface sampler and process for collection and release of analytes

Energy Technology Data Exchange (ETDEWEB)

Addleman, Raymond S; Atkinson, David A; Bays, John T; Chouyyok, Wilaiwan; Cinson, Anthony D; Ewing, Robert G; Gerasimenko, Aleksandr A

2015-02-03

An enhanced swipe sampler and method of making are described. The swipe sampler is made of a fabric containing selected glass, metal oxide, and/or oxide-coated glass or metal fibers. Fibers are modified with silane ligands that are directly attached to the surface of the fibers to functionalize the sampling surface of the fabric. The swipe sampler collects various target analytes including explosives and other threat agents on the surface of the sampler.

Quantum Gibbs Samplers: The Commuting Case

Science.gov (United States)

Kastoryano, Michael J.; Brandão, Fernando G. S. L.

2016-06-01

We analyze the problem of preparing quantum Gibbs states of lattice spin Hamiltonians with local and commuting terms on a quantum computer and in nature. Our central result is an equivalence between the behavior of correlations in the Gibbs state and the mixing time of the semigroup which drives the system to thermal equilibrium (the Gibbs sampler). We introduce a framework for analyzing the correlation and mixing properties of quantum Gibbs states and quantum Gibbs samplers, which is rooted in the theory of non-commutative {mathbb{L}_p} spaces. We consider two distinct classes of Gibbs samplers, one of them being the well-studied Davies generator modelling the dynamics of a system due to weak-coupling with a large Markovian environment. We show that their spectral gap is independent of system size if, and only if, a certain strong form of clustering of correlations holds in the Gibbs state. Therefore every Gibbs state of a commuting Hamiltonian that satisfies clustering of correlations in this strong sense can be prepared efficiently on a quantum computer. As concrete applications of our formalism, we show that for every one-dimensional lattice system, or for systems in lattices of any dimension at temperatures above a certain threshold, the Gibbs samplers of commuting Hamiltonians are always gapped, giving an efficient way of preparing the associated Gibbs states on a quantum computer.

Task plan for test of PRBT prototypic liquid sampler

International Nuclear Information System (INIS)

Jenkins, W.J.

1992-01-01

The primary objective of this task is to determine just how representative Precipitate Reactor Bottom Tank (PRBT) samples taken from the Hydragard trademark prototypic liquid sampler are of the in-tank contents and also to determine the homogeneity of the in-tank contents. This shall be accomplished by a statistical design study sampling plan for paired contrasts of the analysis results of samples taken from: (1) the Hydragard trademark prototypic liquid sampler paired with the more fundamental grab sampler at the lower elevation for the Hydragard trademark prototypic liquid sampler accuracy and (2) the grab sampler at the lower elevation paired with the grab sampler at the upper elevation for the in-tank homogeneity. These measurements are paired together to sharpen the contrast so that, as nearly as possible, only the conditions of the effect under study will differ between the two. This ''split-plot'' arrangement provides increased precision for the contrast under study by canceling out common extraneous effects, thereby enabling the detection of smaller effects. The secondary objective of the task is to determine the level of influence of the major contributors to the overall uncertainty in the sample preparation and measurement process. These major steps include: preparation method (H 2 SO 4 -HF Titanium dissolution); aliquoting and dilution within a dissolution; measurement and long-term behavior of the ICP and AA instruments, as monitored by the measurement of standards and blanks embedded within each block of samples for the measurement sequence. This sampling task, therefore, is mostly devoted to determining the sampler characteristics and is not intended to provide a comprehensive estimate of the overall uncertainty affecting DWPF sample analysis in routine operation

Integrated passive flux measurement in groundwater: design and performance of iFLUX samplers

Science.gov (United States)

Verreydt, Goedele; Razaei, Meisam; Meire, Patrick; Van Keer, Ilse; Bronders, Jan; Seuntjens, Piet

2017-04-01

The monitoring and management of soil and groundwater is a challenge. Current methods for the determination of movement or flux of pollution in groundwater use no direct measurements but only simulations based on concentration measurements and Darcy velocity estimations. This entails large uncertainties which cause remediation failures and higher costs for contaminated site owners. On top of that, the lack of useful data makes it difficult to get approval for a risk-based management approach which completely avoids costly remedial actions. The iFLUX technology is a key development of Dr. Goedele Verreydt at the University of Antwerp and VITO. It is supported by the passive flux measurement technology as invented by Prof. Mike Annable and his team at the University of Florida. The iFLUX technology includes an in situ measurement device for capturing dynamic groundwater quality and quantity, the iFLUX sampler, and an associated interpretation and visualization method. The iFLUX sampler is a modular passive sampler that provides simultaneous in situ point determinations of a time-averaged target compound mass flux and water flux. The sampler is typically installed in a monitoring well where it intercepts the groundwater flow and captures the compounds of interest. The sampler consists of permeable cartridges which are each packed with a specific sorbent matrix. The sorbent matrix of the water flux cartridge is impregnated with known amounts of water soluble resident tracers. These tracers are leached from the matrix at rates proportional to the groundwater flux. The measurements of the contaminants and the remaining resident tracer are used to determine groundwater and target compound fluxes. Exposure times range from 1 week to 6 months, depending on the expected concentration and groundwater flow velocity. The iFLUX sampler technology has been validated and tested at several field projects. Currently, 4 cartridges are tested and available: 1 waterflux cartridge to

Characterization of dFOXO binding sites upstream of the Insulin Receptor P2 promoter across the Drosophila phylogeny.

Directory of Open Access Journals (Sweden)

Dorcas J Orengo

Full Text Available The insulin/TOR signal transduction pathway plays a critical role in determining such important traits as body and organ size, metabolic homeostasis and life span. Although this pathway is highly conserved across the animal kingdom, the affected traits can exhibit important differences even between closely related species. Evolutionary studies of regulatory regions require the reliable identification of transcription factor binding sites. Here we have focused on the Insulin Receptor (InR expression from its P2 promoter in the Drosophila genus, which in D. melanogaster is up-regulated by hypophosphorylated Drosophila FOXO (dFOXO. We have finely characterized this transcription factor binding sites in vitro along the 1.3 kb region upstream of the InR P2 promoter in five Drosophila species. Moreover, we have tested the effect of mutations in the characterized dFOXO sites of D. melanogaster in transgenic flies. The number of experimentally established binding sites varies across the 1.3 kb region of any particular species, and their distribution also differs among species. In D. melanogaster, InR expression from P2 is differentially affected by dFOXO binding sites at the proximal and distal halves of the species 1.3 kb fragment. The observed uneven distribution of binding sites across this fragment might underlie their differential contribution to regulate InR transcription.

A mini-sampler for welding aerosol mounted in close vicinity of the mouth/nose

International Nuclear Information System (INIS)

Liden, Goeran; Surakka, Jouni

2009-01-01

A small personal aerosol mini-sampler to be used inside modern welding visors has been developed. The main object of the mini-sampler has been to sample manganese. The sampler is based on commercially available 13 mm filter holders but modified to incorporate an inlet nozzle made of aluminium. The nominal flow rate of the mini-sampler is 0,75 l/min. The sampler is to be worn mounted on a headset, modified from professional microphone headsets. The headset mounting arrangement was accepted by the welders. The sampling bias of the mini sampler versus the IOM sampler depends on the coarseness of the sampled aerosol. At the lowest concentration ratio of the open-face 25 mm filter holder to the IOM sampler equal to 0,65, the bias of the mini sampler is approximately -26% versus the IOM. The RMS sampling bias of the mini sampler versus the IOM sampler for manganese is -4,6%. The inhalable fraction of welding aerosol mass consists only of 25-55% of welding fume. The rest of the mass is made up of spatter particles and grinding particles. For manganese generally more than 65% is found in the fume.

Operability test report for 211BA flow proportional sampler

International Nuclear Information System (INIS)

Weissenfels, R.D.

1995-01-01

This operability report will verify that the 211-BA flow proportional sampler functions as intended by design. The sampler was installed by Project W-007H and is part of BAT/AKART for the BCE liquid effluent stream

Polychlorinated biphenyl (PCB) contamination in Galveston Bay, Texas: Comparing concentrations and profiles in sediments, passive samplers, and fish.

Science.gov (United States)

Oziolor, Elias M; Apell, Jennifer N; Winfield, Zach C; Back, Jeffrey A; Usenko, Sascha; Matson, Cole W

2018-05-01

The industrialized portion of the Houston Ship Channel (HSC) is heavily contaminated with anthropogenic contaminants, most prominent of which are the polychlorinated biphenyls (PCBs). This contamination has driven adaptive evolution in a keystone species for Galveston Bay, the Gulf killifish (Fundulus grandis). We investigated the geographical extent of PCB impacts by sampling 12 sites, ranging from the heavily industrialized upper portion of the HSC to Galveston Island. At each site, PCB concentrations and profiles were determined in three environmental compartments: sediment, water (polyethylene passive samplers), and fish tissue (resident Gulf killifish). We observed a steep gradient of PCB contamination, ranging from 4.00 to 100,000 ng/g organic carbon in sediment, 290-110,000 ng/g lipid in fish, and 4.5-2300 ng/g polyethylene in passive samplers. The PCB congener profiles in Gulf killifish at the most heavily contaminated sites were shifted toward the higher chlorinated PCBs and were highly similar to the sediment contamination profiles. In addition, while magnitude of total PCB concentrations in sediment and total fish contamination levels were highly correlated between sites, the relative PCB congener profiles in fish and passive samplers were more alike. This strong correlation, along with a lack of dependency of biota-sediment accumulation factors with total contamination rates, confirm the likely non-migratory nature of Gulf killifish and suggest their contamination levels are a good site-specific indicator of contamination in the Galveston Bay area. The spatial gradient of PCB contamination in Galveston Bay was evident in all three matrices studied and was observed effectively using Gulf killifish contamination as an environmentally relevant bioindicator of localized contamination in this environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Optimal relaxed causal sampler using sampled-date system theory

NARCIS (Netherlands)

Shekhawat, Hanumant; Meinsma, Gjerrit

This paper studies the design of an optimal relaxed causal sampler using sampled data system theory. A lifted frequency domain approach is used to obtain the existence conditions and the optimal sampler. A state space formulation of the results is also provided. The resulting optimal relaxed causal

Observation of 45 GHz current waveforms using HTS sampler

International Nuclear Information System (INIS)

Maruyama, M.; Suzuki, H.; Hato, T.; Wakana, H.; Nakayama, K.; Ishimaru, Y.; Horibe, O.; Adachi, S.; Kamitani, A.; Suzuki, K.; Oshikubo, Y.; Tarutani, Y.; Tanabe, K.

2005-01-01

We succeeded in observing high-frequency current waveforms up to 45 GHz using a high-temperature superconducting (HTS) sampler. In this experiment, we used a sampler circuit with a superconducting pickup coil, which magnetically detects current signals flowing through a micro-strip line on a printed board placed outside the cryochamber. This type of measurement enables non-contact current-waveform observation that seems useful for analyses of EMI, defects in LSI, etc. Computer simulation reveals that one of our latest versions of HTS sampler circuits having Josephson transmission lines with optimized biases as buffers has a potential of sampling high-frequency signals with a bandwidth above 100 GHz. To realize the circuit parameters required in the simulations, we developed an HTS circuit fabrication process employing a lower ground plane structure with SrSnO 3 insulating layers. We consider that improvement of the circuit fabrication process and optimization of the pickup coil lead to much higher signal frequency observable by the sampler

Operability test procedure for 211BA flow proportional sampler

International Nuclear Information System (INIS)

Weissenfels, R.D.

1994-01-01

The purpose of this operability test procedure (OTP) is to verify the 211-BA flow proportional sampler system and components function correctly as intended by design. System test will include the sampling system, all associated instrumentation, and Facility Process Monitor and Control System (FPMCS). The combined chemical sewer stream from B Plant flows through sump 211BA-SMP-01 located in 211-BA and is continuously monitored for gamma and beta radiation and pH. 211-BA has been upgraded to include a flow proportional sampler. A specified sample volume will be withdrawn at programmed intervals from the 211BA sump and deposited in a 19 liter plastic carboy. The sampler will be programmed per the vendor installation and operations manual by B Plant instrument maintenance personnel. Samples will be taken during five consecutive sample cycles with the sample volumes and sample frequencies recorded for comparison purposes. Additional tests related to the sampler include the alarm circuitry for loss of power and failure to obtain sample

Evaluation of IOM personal sampler at different flow rates.

Science.gov (United States)

Zhou, Yue; Cheng, Yung-Sung

2010-02-01

The Institute of Occupational Medicine (IOM) personal sampler is usually operated at a flow rate of 2.0 L/min, the rate at which it was designed and calibrated, for sampling the inhalable mass fraction of airborne particles in occupational environments. In an environment of low aerosol concentrations only small amounts of material are collected, and that may not be sufficient for analysis. Recently, a new sampling pump with a flow rate up to 15 L/min became available for personal samplers, with the potential of operating at higher flow rates. The flow rate of a Leland Legacy sampling pump, which operates at high flow rates, was evaluated and calibrated, and its maximum flow was found to be 10.6 L/min. IOM samplers were placed on a mannequin, and sampling was conducted in a large aerosol wind tunnel at wind speeds of 0.56 and 2.22 m/s. Monodisperse aerosols of oleic acid tagged with sodium fluorescein in the size range of 2 to 100 microm were used in the test. The IOM samplers were operated at flow rates of 2.0 and 10.6 L/min. Results showed that the IOM samplers mounted in the front of the mannequin had a higher sampling efficiency than those mounted at the side and back, regardless of the wind speed and flow rate. For the wind speed of 0.56 m/s, the direction-averaged (the average value of all orientations facing the wind direction) sampling efficiency of the samplers operated at 2.0 L/min was slightly higher than that of 10.6 L/min. For the wind speed of 2.22 m/s, the sampling efficiencies at both flow rates were similar for particles < 60 microm. The results also show that the IOM's sampling efficiency at these two different flow rates follows the inhalable mass curve for particles in the size range of 2 to 20 microm. The test results indicate that the IOM sampler can be used at higher flow rates.

Radial diffusive sampler for the determination of 8-h ambient ozone concentrations

International Nuclear Information System (INIS)

Plaisance, H.; Gerboles, M.; Piechocki, A.; Detimmerman, F.; Saeger, E. de

2007-01-01

The 8-h ozone radial diffusive sampler was evaluated according to the CEN protocol for the validation of diffusive samplers. All the parameters regarding the sampler characteristics were found to be consistent with the requirements of this protocol apart from the blank value, which must be evaluated and subtracted at each sampling. The nominal uptake rate was determined in laboratory conditions. However, the uptake rate depends on the mass uptake, temperature, humidity and on the combination of temperature and humidity. Based on laboratory experiments, an empirical model has been established which improved the agreement between the radial sampler and the reference method. This improvement was observed under several different meteorological and emission conditions of sampling. By using the model equation of uptake rate, the data quality objective of 30% for the expanded uncertainty included in the O 3 European Directive, is easily attained. Therefore, the sampler represents an appropriate indicative method. - A passive sampler has been fully validated for monitoring 8-h ozone concentrations in ambient air

Evaluation of air samplers and filter materials for collection and recovery of airborne norovirus.

Science.gov (United States)

Uhrbrand, K; Koponen, I K; Schultz, A C; Madsen, A M

2018-04-01

The aim of this study was to identify the most efficient sampling method for quantitative PCR-based detection of airborne human norovirus (NoV). A comparative experiment was conducted in an aerosol chamber using aerosolized murine norovirus (MNV) as a surrogate for NoV. Sampling was performed using a nylon (NY) filter in conjunction with four kinds of personal samplers: Gesamtstaubprobenahme sampler (GSP), Triplex-cyclone sampler (TC), 3-piece closed-faced Millipore cassette (3P) and a 2-stage NIOSH cyclone sampler (NIO). In addition, sampling was performed using the GSP sampler with four different filter types: NY, polycarbonate (PC), polytetrafluoroethylene (PTFE) and gelatine (GEL). The sampling efficiency of MNV was significantly influenced by both sampler and filter type. The GSP sampler was found to give significantly (P airborne NoV. The identification of a suitable NoV air sampler is an important step towards studying the association between exposure to airborne NoV and infection. © 2017 The Society for Applied Microbiology.

Evaluation of air samplers and filter materials for collection and recovery of airborne norovirus

DEFF Research Database (Denmark)

Uhrbrand, Katrine; Kalevi Koponen, Ismo; Schultz, Anna Charlotte

2017-01-01

V. Sampling was performed using a nylon (NY) filter in conjunction with four kinds of personal samplers; Gesamtstaubprobenahme sampler (GSP), Triplex-cyclone sampler (TC), 3-piece closed-faced Millipore cassette (3P) and a 2-stage NIOSH cyclone sampler (NIO). In addition, sampling was performed using the GSP...

Comparison of PM collection efficiency of Gent and Airmatrics MiniVol portable air sampler

International Nuclear Information System (INIS)

Begum, Bilkis A.; Biswas, Swapan K.

2005-01-01

Gent PM sampler was developed as an integral part of several International Atomic Energy Agency sponsored coordinated research programmes (CRP) for collecting air particulate samples. On the other hand, the MiniVol Portable Air Sampler is a commercial ambient air sampler for particulate matter and non-reactive gases used by different agencies. Air quality management system requires comparable air quality data to be collected by different stake holders for assessment and regulatory purposes. In order to compare the characteristics of Gent sampler with the MiniVol Portable Air Sampler, the reproducibility of the sample mass collection efficiency were examined and the measured mass concentrations were compared. It was found that in case of PM 10 both samplers collect almost same fraction of PM 10 mass when the Gent sampler was operated at 16 litre per minute flow rate. But in case of fine fraction, Portable sampler collects 70% higher PM 2.5 mass concentration compared to the Gent PM 2.2 mass concentrations. This is because, the Gent sampler was typically operated at 16 to 17 lpm resulting in an estimated 50% cut point of 2.2 μm.(author)

High-volume samplers for the assessment of respirable silica content in metal mine dust via direct-on-filter analysis

CSIR Research Space (South Africa)

Cauda, EG

2014-08-01

Full Text Available -site silica quantification in the samples would allow the identification of high-risk tasks and appropriate dedicated control technologies. With the objective to find more timely silica monitoring solutions, the performance of five different samplers...

Pesticide monitoring in surface water and groundwater using passive samplers

Science.gov (United States)

Kodes, V.; Grabic, R.

2009-04-01

Passive samplers as screening devices have been used within a czech national water quality monitoring network since 2002 (SPMD and DGT samplers for non polar substances and metals). The passive sampler monitoring of surface water was extended to polar substances, in 2005. Pesticide and pharmaceutical POCIS samplers have been exposed in surface water at 21 locations and analysed for polar pesticides, perfluorinated compounds, personal care products and pharmaceuticals. Pesticide POCIS samplers in groundwater were exposed at 5 locations and analysed for polar pesticides. The following active substances of plant protection products were analyzed in surface water and groundwater using LC/MS/MS: 2,4,5-T, 2,4-D, Acetochlor, Alachlor, Atrazine, Atrazine_desethyl, Azoxystrobin, Bentazone, Bromacil, Bromoxynil, Carbofuran, Clopyralid, Cyanazin, Desmetryn, Diazinon, Dicamba, Dichlobenil, Dichlorprop, Dimethoat, Diuron, Ethofumesate, Fenarimol, Fenhexamid, Fipronil, Fluazifop-p-butyl, Hexazinone, Chlorbromuron, Chlorotoluron, Imazethapyr, Isoproturon, Kresoxim-methyl, Linuron, MCPA, MCPP, Metalaxyl, Metamitron, Methabenzthiazuron, Methamidophos, Methidathion, Metobromuron, Metolachlor, Metoxuron, Metribuzin, Monolinuron, Nicosulfuron, Phorate, Phosalone, Phosphamidon, Prometryn, Propiconazole, Propyzamide, Pyridate, Rimsulfuron, Simazine, Tebuconazole, Terbuthylazine, Terbutryn, Thifensulfuron-methyl, Thiophanate-methyl and Tri-allate. The POCIS samplers performed very well being able to provide better picture than grab samples. The results show that polar pesticides and also perfluorinated compounds, personal care products and pharmaceuticals as well occur in hydrosphere of the Czech republic. Acknowledgment: Authors acknowledge the financial support of grant No. 2B06095 by the Ministry of Education, Youth and Sports.

Performance of passive samplers for monitoring estuarine water column concentrations: 2. Emerging contaminants.

Science.gov (United States)

Perron, Monique M; Burgess, Robert M; Suuberg, Eric M; Cantwell, Mark G; Pennell, Kelly G

2013-10-01

Measuring dissolved concentrations of emerging contaminants, such as polybrominated diphenyl ethers (PBDEs) and triclosan, can be challenging due to their physicochemical properties resulting in low aqueous solubilities and association with particles. Passive sampling methods have been applied to assess dissolved concentrations in water and sediments primarily for legacy contaminants. Although the technology is applicable to some emerging contaminants, the use of passive samplers with emerging contaminants is limited. In the present study, the performance of 3 common passive samplers was evaluated for sampling PBDEs and triclosan. Passive sampling polymers included low-density polyethylene (PE) and polyoxymethylene (POM) sheets, and polydimethylsiloxane (PDMS)-coated solid-phase microextraction (SPME) fibers. Dissolved concentrations were calculated using measured sampler concentrations and laboratory-derived partition coefficients. Dissolved tri-, tetra-, and pentabrominated PBDE congeners were detected at several of the study sites at very low pg/L concentrations using PE and POM. Calculated dissolved water concentrations of triclosan ranged from 1.7 ng/L to 18 ng/L for POM and 8.8 ng/L to 13 ng/L for PE using performance reference compound equilibrium adjustments. Concentrations in SPME were not reported due to lack of detectable chemical in the PDMS polymer deployed. Although both PE and POM were found to effectively accumulate emerging contaminants from the water column, further research is needed to determine their utility as passive sampling devices for emerging contaminants. © 2013 SETAC.

30 CFR 74.5 - Tests of coal mine dust personal sampler units.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests of coal mine dust personal sampler units... Personal Sampler Unit § 74.5 Tests of coal mine dust personal sampler units. (a) The National Institute for... tests and evaluations to determine whether the pump unit of a CMDPSU that is submitted for approval...

Assessment of bioavailable fraction of POPS in surface water bodies in Johannesburg City, South Africa, using passive samplers: an initial assessment.

Science.gov (United States)

Amdany, Robert; Chimuka, Luke; Cukrowska, Ewa; Kukučka, Petr; Kohoutek, Jiří; Tölgyessy, Peter; Vrana, Branislav

2014-09-01

In this study, the semipermeable membrane device (SPMD) passive samplers were used to determine freely dissolved concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in selected water bodies situated in and around Johannesburg City, South Africa. The devices were deployed for 14 days at each sampling site in spring and summer of 2011. Time weighted average (TWA) concentrations of the water-borne contaminants were calculated from the amounts of analytes accumulated in the passive samplers. In the area of interest, concentrations of analytes in water ranged from 33.5 to 126.8 ng l(-1) for PAHs, from 20.9 to 120.9 pg l(-1) for PCBs and from 0.2 to 36.9 ng l(-1) for OCPs. Chlorinated pesticides were mainly composed of hexachlorocyclohexanes (HCHs) (0.15-36.9 ng l(-1)) and dichlorodiphenyltrichloromethane (DDT) with its metabolites (0.03-0.55 ng l(-1)). By applying diagnostic ratios of certain PAHs, identification of possible sources of the contaminants in the various sampling sites was performed. These ratios were generally inclined towards pyrogenic sources of pollution by PAHs in all study sites except in the Centurion River (CR), Centurion Lake (CL) and Airport River (AUP) that indicated petrogenic origins. This study highlights further need to map up the temporal and spatial variations of these POPs using passive samplers.

A programmable air sampler with adsorption tubes

International Nuclear Information System (INIS)

Riesing, J.; Roetzer, H.; Hick, H.

1997-01-01

The Air Sampler AS3 was utilized for the European Tracer Experiment (ETEX) to measure the concentrations of the perfluorocarbon tracers. At thirty-two sampling points these devices were placed to collect the tracer substances in adsorption tubes for subsequent laboratory analysis in the Environment Institute of the JRC Ispra. The Air Sampler is also suitable for monitoring the environment, particularly of industrial emitters or landfills, by sampling of volatile substances. The Air Sampler AS3 is a portable, user-friendly instrument due to light weight, ruggedness and reliable operation. It is capable of fully automatic sampling of air and gas with 24 adsorption tubes and program-controlled gas flow. Collection times can be programmed freely between 1 sec and 8 days and waiting times between 1 sec and 30 days. Programming is possible via keyboard, memory card or serial interface. A protocol of sampling control data is stored on a memory card giving documentation of sampling conditions. On the memory card there is space for the storage of 10 sampling programs and 10 sets of sampling control data. Before the start of ETEX the AS3 was used in a measurement campaign to measure the background concentrations of the perfluorocarbon tracers in Austria. In the provinces of Upper Austria and Salzburg the Air Sampler is used by the departments for environmental protection for the monitoring of BTX-concentrations in air. (author)

Performance characteristics of a low-volume PM10 sampler

Science.gov (United States)

Four identical PM10 pre-separators, along with four identical low-volume (1m3 hr-1) total suspended particulate (TSP) samplers were tested side-by-side in a controlled laboratory particulate matter (PM) chamber. The four PM10 and four TSP samplers were also tested in an oil pipe-cleaning field to ev...

Passive samplers and community science in regional air quality measurement, education and communication.

Science.gov (United States)

DeForest Hauser, Cindy; Buckley, Alexandra; Porter, Juliana

2015-08-01

Charlotte, in Mecklenburg County, North Carolina, was ranked in the top ten cities with the worst air quality for ozone in the United States by the American Lung Association from 2009 to 2011. Nearby counties that may experience similar air quality do not have state or county monitors. This study utilized NOx and ozone Ogawa passive samplers and community scientists to monitor air quality in five counties surrounding Charlotte and increase public engagement in air quality issues. Community scientists deployed samplers weekly at a residential site within each county. Samples were analyzed using spectrophotometry and ion chromatography. Elevated NOx concentrations were observed in four of the five counties relative to those with existing monitors. Ozone concentrations showed little county to county variation, except Iredell and Cabarrus which had higher concentrations than Rowan. Community involvement in this work led to an increase in local dissemination of the results, thus increasing air quality awareness. Copyright © 2014 Elsevier Ltd. All rights reserved.

The neighborhood MCMC sampler for learning Bayesian networks

Science.gov (United States)

Alyami, Salem A.; Azad, A. K. M.; Keith, Jonathan M.

2016-07-01

Getting stuck in local maxima is a problem that arises while learning Bayesian networks (BNs) structures. In this paper, we studied a recently proposed Markov chain Monte Carlo (MCMC) sampler, called the Neighbourhood sampler (NS), and examined how efficiently it can sample BNs when local maxima are present. We assume that a posterior distribution f(N,E|D) has been defined, where D represents data relevant to the inference, N and E are the sets of nodes and directed edges, respectively. We illustrate the new approach by sampling from such a distribution, and inferring BNs. The simulations conducted in this paper show that the new learning approach substantially avoids getting stuck in local modes of the distribution, and achieves a more rapid rate of convergence, compared to other common algorithms e.g. the MCMC Metropolis-Hastings sampler.

COMPARISON OF THE PARTICLE SIZE DISTRIBUTION OF HEAVY-DUTY DIESEL EXHAUST USING A DILUTION TAIL-PIPE SAMPLER AND IN-PLUME SAMPLER DURING ON-ROAD OPERATION

Science.gov (United States)

The paper compares the particle size distribution of heavy-duty diesel exhaust using a dilution tail-pipe sampler and an in-plume sampler during on-road operation. EPA's On-road Diesel Emissions Characterization Facility, modified to incorporate particle measurement instrumentat...

Assembly, operation and disassembly manual for the Battelle Large Volume Water Sampler (BLVWS)

International Nuclear Information System (INIS)

Thomas, V.W.; Campbell, R.M.

1984-12-01

Assembly, operation and disassembly of the Battelle Large Volume Water Sampler (BLVWS) are described in detail. Step by step instructions of assembly, general operation and disassembly are provided to allow an operator completely unfamiliar with the sampler to successfully apply the BLVWS to his research sampling needs. The sampler permits concentration of both particulate and dissolved radionuclides from large volumes of ocean and fresh water. The water sample passes through a filtration section for particle removal then through sorption or ion exchange beds where species of interest are removed. The sampler components which contact the water being sampled are constructed of polyvinylchloride (PVC). The sampler has been successfully applied to many sampling needs over the past fifteen years. 9 references, 8 figures

Summary report on the design of the retained gas sampler system (retained gas sampler, extruder and extractor)

International Nuclear Information System (INIS)

Wootan, D.W.; Bolden, R.C.; Bridges, A.E.; Cannon, N.S.; Chastain, S.A.; Hey, B.E.; Knight, R.C.; Linschooten, C.G.; Pitner, A.L.; Webb, B.J.

1994-01-01

This document summarizes work performs in Fiscal Year 1994 to develop the three main components of Retained Gas Sampler System (RGSS). These primary components are the Retained Gas Sampler (RGS), the Retained Gas Extruder (RGE), and the Retained Gas Extractor (RGEx). The RGS is based on the Westinghouse Hanford Company (WHC) Universal Sampler design, and includes modifications to reduce gas leakage. The primary data priorities for the RGSS are to measure the void fraction and the flammable gas concentration in the waste sample. Significant progress has been made in developing the RGSS. The RGSS is being developed by WHC to extract a representative waste sample from a Flammable Gas Watch List Tanks and to measure both the amount and composition of free and open-quotes boundclose quotes gases. Sudden releases of flammable gas mixtures are a safety concern for normal waste storage operations and eventual waste retrieval. Flow visualization testing was used to identify important fluid dynamic issues related to the sampling process. The primary data priorities for the RGSS are to measure the void fraction and the flammable gas concentration in the waste sample. The safety analysis for the RGSS is being performed by Los Alamos National Laboratory and is more than sixty percent (60%) complete

Suspended-sediment loads, reservoir sediment trap efficiency, and upstream and downstream channel stability for Kanopolis and Tuttle Creek Lakes, Kansas, 2008-10

Science.gov (United States)

Juracek, Kyle E.

2011-01-01

Continuous streamflow and turbidity data collected from October 1, 2008, to September 30, 2010, at streamgage sites upstream and downstream from Kanopolis and Tuttle Creek Lakes, Kansas, were used to compute the total suspended-sediment load delivered to and released from each reservoir as well as the sediment trap efficiency for each reservoir. Ongoing sedimentation is decreasing the ability of the reservoirs to serve several purposes including flood control, water supply, and recreation. River channel stability upstream and downstream from the reservoirs was assessed using historical streamgage information. For Kanopolis Lake, the total 2-year inflow suspended-sediment load was computed to be 600 million pounds. Most of the suspended-sediment load was delivered during short-term, high-discharge periods. The total 2-year outflow suspended-sediment load was computed to be 31 million pounds. Sediment trap efficiency for the reservoir was estimated to be 95 percent. The mean annual suspended-sediment yield from the upstream basin was estimated to be 129,000 pounds per square mile per year. No pronounced changes in channel width were evident at five streamgage sites located upstream from the reservoir. At the Ellsworth streamgage site, located upstream from the reservoir, long-term channel-bed aggradation was followed by a period of stability. Current (2010) conditions at five streamgages located upstream from the reservoir were typified by channel-bed stability. At the Langley streamgage site, located immediately downstream from the reservoir, the channel bed degraded 6.15 feet from 1948 to 2010. For Tuttle Creek Lake, the total 2-year inflow suspended-sediment load was computed to be 13.3 billion pounds. Most of the suspended-sediment load was delivered during short-term, high-discharge periods. The total 2-year outflow suspended-sediment load was computed to be 327 million pounds. Sediment trap efficiency for the reservoir was estimated to be 98 percent. The mean

AN AFFINE-INVARIANT SAMPLER FOR EXOPLANET FITTING AND DISCOVERY IN RADIAL VELOCITY DATA

International Nuclear Information System (INIS)

Hou Fengji; Hogg, David W.; Goodman, Jonathan; Weare, Jonathan; Schwab, Christian

2012-01-01

Markov chain Monte Carlo (MCMC) proves to be powerful for Bayesian inference and in particular for exoplanet radial velocity fitting because MCMC provides more statistical information and makes better use of data than common approaches like chi-square fitting. However, the nonlinear density functions encountered in these problems can make MCMC time-consuming. In this paper, we apply an ensemble sampler respecting affine invariance to orbital parameter extraction from radial velocity data. This new sampler has only one free parameter, and does not require much tuning for good performance, which is important for automatization. The autocorrelation time of this sampler is approximately the same for all parameters and far smaller than Metropolis-Hastings, which means it requires many fewer function calls to produce the same number of independent samples. The affine-invariant sampler speeds up MCMC by hundreds of times compared with Metropolis-Hastings in the same computing situation. This novel sampler would be ideal for projects involving large data sets such as statistical investigations of planet distribution. The biggest obstacle to ensemble samplers is the existence of multiple local optima; we present a clustering technique to deal with local optima by clustering based on the likelihood of the walkers in the ensemble. We demonstrate the effectiveness of the sampler on real radial velocity data.

Differences in particle size distributions collected by two wood dust samplers: preliminary findings

International Nuclear Information System (INIS)

Campopiano, A.; Olori, A.; Basili, F.; Ramires, D.; Zakrzewska, A.M.

2008-01-01

The International Agency for Research on Cancer (IARC) classification of wood dust as carcinogenic to humans, and the threshold limit value (TLV) of 5 mg/m 3 weighted over an 8-hour work day as defined by Italian legislation, have raised the issue of dust risk assessments in all woodworking environments. The aim is to characterize the particle size distribution for wood particles collected by two samplers used for collecting the inhalable fraction: the IOM sampler (Institute of Occupational Medicine, Edinburgh, Scotland) and the conical sampler also known in Italy as conetto. These two sampling heads were chosen mainly because the Italian conical sampler, used in the past for total dust sampling, is the most widely used by the Italian Prevention Services and analysis laboratories in general, whereas the IOM sampler was specifically designed to collect the inhalable fraction of airborne particles. The devices were placed side by side within the worker's breathing zone. In addition, another IOM sampler not connected to the personal sampling pump was placed on the same worker, thus functioning as a passive sampler capable of collecting projectile particles normally produced during processing. A Scanning Electron Microscope (SEM) coupled with energy dispersive X-ray spectrometry (EDAX) was used to count the number of particles collected on the sampling filters. The size of each particle identified by the SEM was determined by measuring its mean diameter. The SEM analysis revealed that the average size of the largest particles collected by the conetto sampler did not exceed 150 μm, whereas the size of particles collected by the IOM sampler was up to 350 μm. Indeed, the analysis of the filters of the passive IOM samplers showed that particles with mean diameters larger than 100 μm were collected, although the calculated percentage was very low (on average, approximately 1%). This does not mean that their gravimetric contribution is negligible; indeed, the weight of

Performance of prototype high-flow inhalable dust sampler in a livestock production facility.

Science.gov (United States)

Anthony, T Renée; Cai, Changjie; Mehaffy, John; Sleeth, Darrah; Volckens, John

2017-05-01

A high-flow inhalable sampler, designed for operational flow rates up to 10 L/min using computer simulations and examined in wind tunnel experiments, was evaluated in the field. This prototype sampler was deployed in collocation with an IOM (the benchmark standard sampler) in a swine farrowing building to examine the sampling performance for assessing concentrations of inhalable particulate mass and endotoxin. Paired samplers were deployed for 24 hr on 19 days over a 3-month period. On each sampling day, the paired samplers were deployed at three fixed locations and data were analyzed to identify agreement and to examine systematic biases between concentrations measured by these samplers. Thirty-six paired gravimetric samples were analyzed; insignificant, unsubstantial differences between concentrations were identified between the two samplers (p = 0.16; mean difference 0.03 mg/m 3 ). Forty-four paired samples were available for endotoxin analysis, and a significant (p = 0.001) difference in endotoxin concentration was identified: the prototype sampler, on average, had 120 EU/m 3 more endotoxin than did the IOM samples. Since the same gravimetric samples were analyzed for endotoxin content, the endotoxin difference is likely attributable to differences in endotoxin extraction. The prototype's disposable thin-film polycarbonate capsule was included with the filter in the 1-hr extraction procedure while the internal plastic cassette of the IOM required a rinse procedure that is susceptible to dust losses. Endotoxin concentrations measured with standard plastic IOM inserts that follow this rinsing procedure may underestimate the true endotoxin exposure concentrations. The maximum concentrations in the study (1.55 mg/m 3 gravimetric, 2328 EU/m 3 endotoxin) were lower than other agricultural or industrial environments. Future work should explore the performance of the prototype sampler in dustier environments, where concentrations approach particulates not otherwise

Development of automatic smear testing sampler for radioactive contamination of floor in nuclear power plant

International Nuclear Information System (INIS)

Nozawa, Katsuro; Hashimoto, Hiroshi; Shinohara, Yohtaro; Iwaki, Kiyotaka

1980-01-01

The floor contamination with radioactive substances in the controlled area of nuclear power stations is strictly controlled, and it is tested by the smear method, wiping the contaminants on floors with filter papers or cloths and measuring the radioactive intensity to obtain contamination density. The works are very laborious, therefore the automatic smear sampler was developed. Simple operation, shortening of time required for wiping, constant and high efficiency of wiping, and easy numbering of samples were the aims in the development. The method of wiping, the mechanisms of wiping, cloth feeding and running, the surface pressure at the time of wiping, the number of times of wiping and required motor torque were studied. The outline of the developed sampler is explained. The performance of the sampler was compared with manual wiping. The efficiency of wiping with the sampler was 92%, assuming manual wiping as 100. Difference was not observed between careful manual wiping and the wiping with the sampler, therefore it was confirmed that this automatic floor smear sampler can be put in practical use. By conventional manual sampling, the maximum limit was about 400 samples/man-day, but when this sampler is used, about 1000 samples/sampler-day is possible. At present, this sampler is operated in Hamaoka Nuclear Power Station. (Kako, I.)

A constant flow filter air sampler for workplace environments

International Nuclear Information System (INIS)

Parulian, A.; Rodgers, J.C.; McFarland, A.R.

1996-01-01

A filter air sampler has been developed for sampling radionuclide aerosol particles form the workplace environment. It provides easy filter changing, constant flow sampling, and a visual display to indicate proper operation. An experimental study was conducted to characterize the collection efficiency of the sampler as affected by variations in room air velocity, particle size, sampling flow rate, inlet geometry, and inlet orientation to the free stream. Tests were carried out in a wing tunnel at velocities between 0.3 m s -1 and 2.0 m s -1 , which is a range that covers anticipated velocities in the typical highly ventilated workplace environment of a nuclear facility. Nearly monodisperse aerosols with sizes between 5 and 20 μm aerodynamic diameter were sampled at flow rates between 28.3 and 84.9 L min -1 . Inlet orientations of 0 degree, 90 degree, and 180 degree from the horizontal were selected for evaluation. When the sampler was oriented at 0 degree over various ranges of free stream velocities, sampling flow rates and particle sizes, the transmission efficiency of aerosol was typically greater than 95%. The transmission efficiencies varied form 80% to 106% for 10-μm aerodynamic diameter particles over the previously noted range of free stream velocities and inlet orientations. Uniformity of deposits of 10 μm aerodynamic diameter particles on collection filters was examined for a sampling rate of 57 L min -1 , a sampler orientation of 90 degree into the wind and wind speeds of 0.3-2 m s -1 . The coefficients of variation for the areal density of the deposits ranged from 6.1% to 37.2%. A miniature critical flow venturi with a constant sampling flow rate of 57 L min -1 was developed for application to the new filter air sampler. It was demonstrated that the performance of the new filter air sampler is quite acceptable over a wide range of conditions. 31 refs., 8 figs., 1 tab

Field performance evaluation during fog-dominated wintertime of a newly developed denuder-equipped PM1 sampler.

Science.gov (United States)

Singh, Dharmendra Kumar; Lakshay; Gupta, Tarun

2014-03-01

This study presents the performance evaluation of a novel denuder-equipped PM1 (particles having aerodynamic diameter less than 1 μm) sampler, tested during fog-dominated wintertime, in the city of Kanpur, India. One PM1 sampler and one denuder-equipped PM1 sampler were co-located to collect ambient PM1 for 25 days. The mean PM1 mass concentration measured on foggy days with the PM1 sampler and the denuder-equipped PM1 sampler was found to be 165.95 and 135.48 μg/m(3), respectively. The mean PM1 mass concentration measured on clear days with the PM1 sampler and the denuder-equipped PM1 sampler was observed to be 159.66 and 125.14 μg/m(3), respectively. The mass concentration with denuder-fitted PM1 sampler for both foggy and clear days was always found less than the PM1 sampler. The same drift was observed in the concentrations of water-soluble ions and water-soluble organic carbon (WSOC). Moreover, it was observed that the use of denuder leads to a significant reduction in the PM positive artifact. The difference in the concentration of chemical species obtained by two samplers indicates that the PM1 sampler without denuder had overestimated the concentrations of chemical species in a worst-case scenario by almost 40 %. Denuder-fitted PM1 sampler can serve as a useful sampling tool in estimating the true values for nitrate, ammonium, potassium, sodium and WSOC present in the ambient PM.

Development of a personal multi-pollutant exposure sampler for particulate matter and criteria gases

Energy Technology Data Exchange (ETDEWEB)

Chang, I.T.; Sarnat, J.; Wolfson, J.M.; Rojas-Bracho, L.; Suh, H.H.; Koutrakis, P. [Harvard Univ., Boston, MA (United States). School of Public Health

1999-12-01

A novel personal sampler is reported which allows simultaneous measurement of PM{sub 2,5}, and PM{sub 10}, ozone, nitrogen dioxide, and sulfur dioxide. This method combines previously used samplers for personal mass measurement with passive samplers for criteria gases and uses a single pump. Preliminarily results are reported for laboratory chamber tests and field comparisons with reference methods for both mass and criteria gases. These results demonstrate the suitability of this sampler of exposure assessment studies. (authors)

A cheap and simple passive sampler using silicone rubber for the ...

African Journals Online (AJOL)

caffeine, personal care products, pharmaceuticals, pesticides and polycyclic aromatic hydrocarbons. Keywords: passive sampler, silicone rubber (PDMS) tubing, GCxGC-TOFMS, ..... concentrations may be derived by using performance reference compounds to determine in situ passive sampler sampling rates followed by ...

Investigation of a new passive sampler for the detection of munitions compounds in marine and freshwater systems.

Science.gov (United States)

Warren, Joseph K; Vlahos, Penny; Smith, Richard; Tobias, Craig

2018-07-01

Over the last century, unexploded ordnances have been disposed of in marine shelf systems because of a lack of cost-effective alternatives. Underwater unexploded ordnances have the potential to leak 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitro-1,3,5-triazine (RDX), commonly used chemical munitions, and contaminate local waters, biota, and sediments. The rate at which this contamination occurs in the environment is relatively unknown, and the cost- and time-prohibitive nature of sampling across sites makes mapping difficult. In the present study we assessed the efficacy of ethylene-vinyl acetate (EVA) for sampling relatively soluble munitions compounds over a range of environmental conditions (i.e., changes in temperature and salinity) and optimized the composition of the passive sampling polymer. The EVA sampler was able to successfully detect ambient concentrations of lingering munitions compounds from field sites containing unexploded ordnances. The sampler affinity for the munitions in terms of an EVA-water partition coefficient was greater than the standard octanol water values for each target compound. Partitioning of compounds onto EVA over the natural ranges of salinity did not change significantly, although uptake varied consistently and predictably with temperature. Increasing the vinyl acetate to ethylene ratio of the polymer corresponded to an increase in uptake capacity, consistent with enhanced dipole-dipole interactions between the munitions and the polymer. This sampler provides a cost-effective means to map and track leakage of unexploded ordnances both spatially and temporally. Environ Toxicol Chem 2018;37:1990-1997. © 2018 SETAC. © 2018 SETAC.

A directional passive air sampler for monitoring polycyclic aromatic hydrocarbons (PAHs) in air mass

International Nuclear Information System (INIS)

Tao, S.; Liu, Y.N.; Lang, C.; Wang, W.T.; Yuan, H.S.; Zhang, D.Y.; Qiu, W.X.; Liu, J.M.; Liu, Z.G.; Liu, S.Z.; Yi, R.; Ji, M.; Liu, X.X.

2008-01-01

A passive air sampler was developed for collecting polycyclic aromatic hydrocarbons (PAHs) in air mass from various directions. The airflow velocity within the sampler was assessed for its responses to ambient wind speed and direction. The sampler was examined for trapped particles, evaluated quantitatively for influence of airflow velocity and temperature on PAH uptake, examined for PAH uptake kinetics, calibrated against active sampling, and finally tested in the field. The airflow volume passing the sampler was linearly proportional to ambient wind speed and sensitive to wind direction. The uptake rate for an individual PAH was a function of airflow velocity, temperature and the octanol-air partitioning coefficient of the PAH. For all PAHs with more than two rings, the passive sampler operated in a linear uptake phase for three weeks. Different PAH concentrations were obtained in air masses from different directions in the field test. - A novel directional passive air sampler was developed and tested for monitoring PAHs in air masses from different directions

Microfluidic Air Sampler for Highly Efficient Bacterial Aerosol Collection and Identification.

Science.gov (United States)

Bian, Xiaojun; Lan, Ying; Wang, Bing; Zhang, Yu Shrike; Liu, Baohong; Yang, Pengyuan; Zhang, Weijia; Qiao, Liang

2016-12-06

The early warning capability of the presence of biological aerosol threats is an urgent demand in ensuing civilian and military safety. Efficient and rapid air sample collection in relevant indoor or outdoor environment is a key step for subsequent analysis of airborne microorganisms. Herein, we report a portable battery-powered sampler that is capable of highly efficient bioaerosol collection. The essential module of the sampler is a polydimethylsiloxane (PDMS) microfluidic chip, which consisted of a 3-loop double-spiral microchannel featuring embedded herringbone and sawtooth wave-shaped structures. Vibrio parahemolyticus (V. parahemolyticus) as a model microorganism, was initially employed to validate the bioaerosol collection performance of the device. Results showed that the sampling efficacy reached as high as >99.9%. The microfluidic sampler showed greatly improved capturing efficiency compared with traditional plate sedimentation methods. The high performance of our device was attributed to the horizontal inertial centrifugal force and the vertical turbulence applied to airflow during sampling. The centrifugation field and turbulence were generated by the specially designed herringbone structures when air circulated in the double-spiral microchannel. The sawtooth wave-shaped microstructure created larger specific surface area for accommodating more aerosols. Furthermore, a mixture of bacterial aerosols formed by V. parahemolyticus, Listeria monocytogenes, and Escherichia coli was extracted by the microfluidic sampler. Subsequent integration with mass spectrometry conveniently identified the multiple bacterial species captured by the sampler. Our developed stand-alone and cable-free sampler shows clear advantages comparing with conventional strategies, including portability, easy-to-use, and low cost, indicating great potential in future field applications.

Reuter Centrifugal Air Sampler: Measurement of Effective Airflow Rate and Collection Efficiency

OpenAIRE

Macher, J. M.; First, M. W.

1983-01-01

Incorrect calculation of effective air sampling rate and disregard of differences in collection efficiency among samplers can lead to false conclusions about the usefulness of samplers for measuring concentrations of airborne microorganisms.

A mathematics sampler topics for the liberal arts

CERN Document Server

Berlinghoff, William P; Skrien, Dale

2001-01-01

Now in its fifth edition, A Mathematics Sampler presents mathematics as both science and art, focusing on the historical role of mathematics in our culture. It uses selected topics from modern mathematics-including computers, perfect numbers, and four-dimensional geometry-to exemplify the distinctive features of mathematics as an intellectual endeavor, a problem-solving tool, and a way of thinking about the rapidly changing world in which we live. A Mathematics Sampler also includes unique LINK sections throughout the book, each of which connects mathematical concepts with areas of interest th

Computational fluid dynamics (CFD) simulation of a newly designed passive particle sampler.

Science.gov (United States)

Sajjadi, H; Tavakoli, B; Ahmadi, G; Dhaniyala, S; Harner, T; Holsen, T M

2016-07-01

In this work a series of computational fluid dynamics (CFD) simulations were performed to predict the deposition of particles on a newly designed passive dry deposition (Pas-DD) sampler. The sampler uses a parallel plate design and a conventional polyurethane foam (PUF) disk as the deposition surface. The deposition of particles with sizes between 0.5 and 10 μm was investigated for two different geometries of the Pas-DD sampler for different wind speeds and various angles of attack. To evaluate the mean flow field, the k-ɛ turbulence model was used and turbulent fluctuating velocities were generated using the discrete random walk (DRW) model. The CFD software ANSYS-FLUENT was used for performing the numerical simulations. It was found that the deposition velocity increased with particle size or wind speed. The modeled deposition velocities were in general agreement with the experimental measurements and they increased when flow entered the sampler with a non-zero angle of attack. The particle-size dependent deposition velocity was also dependent on the geometry of the leading edge of the sampler; deposition velocities were more dependent on particle size and wind speeds for the sampler without the bend in the leading edge of the deposition plate, compared to a flat plate design. Foam roughness was also found to have a small impact on particle deposition. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Pilot Study: The UNC Passive Aerosol Sampler in a Working Environment.

Science.gov (United States)

Shirdel, Mariam; Wingfors, Håkan; Andersson, Britt M; Sommar, Johan N; Bergdahl, Ingvar A; Liljelind, Ingrid E

2017-10-01

Dust is generally sampled on a filter using air pumps, but passive sampling could be a cost-effective alternative. One promising passive sampler is the University of North Carolina passive aerosol sampler (UNC sampler). The aim of this study is to characterize and compare the UNC sampler's performance with PM10 and PM2.5 impactors in a working environment. Area sampling was carried out at different mining locations using UNC samplers in parallel with PM2.5 and PM10 impactors. Two different collection surfaces, polycarbonate (PC) and carbon tabs (CT), were employed for the UNC sampling. Sampling was carried out for 4-25 hours. The UNC samplers underestimated the concentrations compared to PM10 and PM2.5 impactor data. At the location with the highest aerosol concentration, the time-averaged mean of PC showed 24% and CT 35% of the impactor result for PM2.5. For PM10, it was 39% with PC and 58% with CT. Sample blank values differed between PC and CT. For PM2.5, PC blank values were ~7 times higher than those of CT, but only 1.8 times higher for PM10. The blank variations were larger for PC than for CT. Particle mass concentrations appear to be underestimated by the UNC sampler compared to impactors, more so for PM2.5 than for PM10. CT may be preferred as a collection surface because the blank values were lower and less variable than for PC. Future validations in the working environment should include respirable dust sampling. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Sampling of BTX in Hat Yai city using cost effective laboratory-built PCB passive sampler.

Science.gov (United States)

Subba, Jas Raj; Thammakhet, Chongdee; Thavarungkul, Panote; Kanatharana, Proespichaya

2016-08-23

A laboratory-built printed circuit board (PCB) passive sampler used for the monitoring of xylene and styrene in copy print shops was re-validated for detecting benzene, toluene and xylene (BTX) and applied for the sampling of ambient air from Hat Yai city, Songkhla, Thailand, in the month of November 2014. For monitoring, the PCB passive samplers were exposed to target analytes in 16 locations covering high to low exposure areas. After sampling, the samplers were thermally desorbed and the analytes were trapped by multi-walled carbon nanotubes packed into a micro-preconcentrator coupled to a gas chromatograph (GC) equipped with a flame ionization detector. At the optimum GC operating conditions, the linear dynamic ranges for BTX were 0.06-5.6 µg for benzene, 0.07-2.2 µg for toluene and 0.23-2.5 µg for xylene with R(2) > 0.99 with the limits of detection being 6.6, 6.8 and 19 ng for benzene, toluene and xylene, respectively. The concentrations of BTX in the 16 sampling sites were in the range of N.D.-1.3 ± 1.6, 4.50 ± 0.76-49.6 ± 3.7 and 1.00 ± 0.21-39.6 ± 3.1 µg m(-3), respectively. When compared to past studies, there had been an increase in the benzene concentration.

Overflow type sodium sampler for FBTR circuits

International Nuclear Information System (INIS)

Muralidaran, P.; Ganesan, V.; Chandran, K.; Periaswami, G.

1996-01-01

Obtaining a representative sample is crucial for getting reliable results in sodium analysis. Sampling liquid sodium reliability is complicated since impurities segregate while cooling. Selective sorption of certain elements calls for use of different crucible materials for various sodium impurities. Sampling methods currently in use such as flow through sampling and dip sampling are not the proper methods as they can not take care of the above problems. An overflow type sampler where the entire sample contained in a crucible can be used for analysis thus obviating problems due to segregation has been developed for use in Fast Breeder Test Reactor (FBTR). This report describes the construction and operation of this sampler. (author)

Sampling Efficiency and Performance of Selected Thoracic Aerosol Samplers.

Science.gov (United States)

Görner, Peter; Simon, Xavier; Boivin, Alexis; Bau, Sébastien

2017-08-01

Measurement of worker exposure to a thoracic health-related aerosol fraction is necessary in a number of occupational situations. This is the case of workplaces with atmospheres polluted by fibrous particles, such as cotton dust or asbestos, and by particles inducing irritation or bronchoconstriction such as acid mists or flour dust. Three personal and two static thoracic aerosol samplers were tested under laboratory conditions. Sampling efficiency with respect to particle aerodynamic diameter was measured in a horizontal low wind tunnel and in a vertical calm air chamber. Sampling performance was evaluated against conventional thoracic penetration. Three of the tested samplers performed well, when sampling the thoracic aerosol at nominal flow rate and two others performed well at optimized flow rate. The limit of flow rate optimization was found when using cyclone samplers. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Evaluating the Relationship between Equilibrium Passive Sampler Uptake and Aquatic Organism Bioaccumulation,

Science.gov (United States)

Objectives. This review evaluates passive sampler uptake of hydrophobic organic contaminants (HOCs) in water column and interstitial water exposures as a surrogate for organism bioaccumulation. Approach/Activities. Fifty-five studies were found where both passive sampler uptake...

UWB Sampler for Wireless Communications and Radar

National Research Council Canada - National Science Library

Han, Jeongwoo; Nguyen, Cam

2005-01-01

An ultra wideband (UWB) sampler, realized using step recovery and Schottky diodes on coplanar waveguide, coplanar strips and slotlines, has been developed for UWB wireless communications and radar systems...

Improving the UNC Passive Aerosol Sampler Model Based on Comparison with Commonly Used Aerosol Sampling Methods.

Science.gov (United States)

Shirdel, Mariam; Andersson, Britt M; Bergdahl, Ingvar A; Sommar, Johan N; Wingfors, Håkan; Liljelind, Ingrid E

2018-03-12

In an occupational environment, passive sampling could be an alternative to active sampling with pumps for sampling of dust. One passive sampler is the University of North Carolina passive aerosol sampler (UNC sampler). It is often analysed by microscopic imaging. Promising results have been shown for particles above 2.5 µm, but indicate large underestimations for PM2.5. The aim of this study was to evaluate, and possibly improve, the UNC sampler for stationary sampling in a working environment. Sampling was carried out at 8-h intervals during 24 h in four locations in an open pit mine with UNC samplers, respirable cyclones, PM10 and PM2.5 impactors, and an aerodynamic particle sizer (APS). The wind was minimal. For quantification, two modifications of the UNC sampler analysis model, UNC sampler with hybrid model and UNC sampler with area factor, were compared with the original one, UNC sampler with mesh factor derived from wind tunnel experiments. The effect of increased resolution for the microscopic imaging was examined. Use of the area factor and a higher resolution eliminated the underestimation for PM10 and PM2.5. The model with area factor had the overall lowest deviation versus the impactor and the cyclone. The intraclass correlation (ICC) showed that the UNC sampler had a higher precision and better ability to distinguish between different exposure levels compared to the cyclone (ICC: 0.51 versus 0.24), but lower precision compared to the impactor (PM10: 0.79 versus 0.99; PM2.5: 0.30 versus 0.45). The particle size distributions as calculated from the different UNC sampler analysis models were visually compared with the distributions determined by APS. The distributions were obviously different when the UNC sampler with mesh factor was used but came to a reasonable agreement when the area factor was used. High resolution combined with a factor based on area only, results in no underestimation of small particles compared to impactors and cyclones and a

Application of XAD-2 resin-based passive samplers and SPME–GC–MS/MS analysis for the monitoring of spatial and temporal variations of atmospheric pesticides in Luxembourg

International Nuclear Information System (INIS)

Schummer, Claude; Tuduri, Ludovic; Briand, Olivier; Appenzeller, Brice M.; Millet, Maurice

2012-01-01

Passive air sampling has been shown to be a very interesting alternative to high-volume sampling by overcoming its disadvantages (size, weight, expensiveness). However, to date, only limited data is available about passive air sampling of current-use pesticides. In order to test if passive samplers allow monitoring of spatial and temporal variations of atmospheric pesticide concentrations, five XAD-2-resin based passive air samplers were deployed at five locations in Luxembourg. Samplers were analyzed using accelerated solvent extraction coupled to solid-phase microextraction and gas chromatography with tandem mass spectrometry. Collected data was used to study the spatial and temporal variations of the concentrations of the compounds. Twenty two pesticides were detected between March and October, while no pesticides were detected from November to February. Highest concentrations were measured on the rural sites, suggesting that the used XAD-2 resin-based passive samplers allow the simultaneous monitoring of multiple current-use pesticides and identifying spatial and temporal variations. - Highlights: ► XAD-2 passive sampling of current-used pesticides. ► Coupling of ASE and SPME–GC–MS/MS for the analysis of pesticides in XAD-2 passive sampling. ► XAD-2 passive samplers suitable for current-used pesticides atmospheric sampling. ► XAD-2 passive samplers suitable for spatial and temporal atmospheric concentrations variations. - XAD-2 passive sampling of current-use pesticides in the atmosphere.

Performances of an atmospheric tritium sampler and its application

International Nuclear Information System (INIS)

Inoue, Yoshikazu; Kahn, B.; Carter, M.W.

1983-01-01

A sampling system for atmospheric tritium in the form of water vapor, hydrogen and hydrocarbons was designed and built. The air was passed first through molecular sieve which adsorbed water vapor, then over palladium catalyst which oxidized hydrogen and adsorbed resulting water in situ, and finally over hot Hopcalite catalyst, which oxidized hydrocarbons and the resulting water was adsorbed on a following molecular sieve column. Three water samples were extracted from adsorbers and their tritium contents were measured by liquid scintillation counting. Performances of this sampler were examined for retrieval of tritiated water from molecular sieve, oxidation of hydrogen on palladium catalyst and oxidation of methane on Hopcalite. The portable sampler was applied to analyze tritium in a duct air of a heavy water moderated research reactor. More than 99% of total tritium was in vapor form. Trace amounts of tritiated hydrogen and hydrocarbon were also detected. This tritium sampler is applicable to detect all of atmospheric tritium as high as ten times of ambient levels. (author)

A Reconnaissance of selected organic compounds in streams in tribal lands in Central Oklahoma, January-February 2009

Science.gov (United States)

Becker, Carol J.

2010-01-01

The U.S. Geological Survey worked in cooperation with the U.S. Environmental Protection Agency and the Kickapoo Tribe of Oklahoma on two separate reconnaissance projects carried out concurrently. Both projects entailed the use of passive samplers as a sampling methodology to investigate the detection of selected organic compounds at stream sites in jurisdictional areas of several tribes in central Oklahoma during January-February 2009. The focus of the project with the U.S. Environmental Protection Agency was the detection of pesticides and pesticide metabolites using Semipermeable Membrane Devices at five stream sites in jurisdictional areas of several tribes. The project with the Kickapoo Tribe of Oklahoma focused on the detection of pesticides, pesticide metabolites, polycyclic aromatic hydrocarbons, polychlorinated biphenyl compounds, and synthetic organic compounds using Semipermeable Membrane Devices and Polar Organic Chemical Integrative Samplers at two stream sites adjacent to the Kickapoo tribal lands. The seven stream sites were located in central Oklahoma on the Cimarron River, Little River, North Canadian River, Deep Fork, and Washita River. Extracts from SPMDs submerged at five stream sites, in cooperation with the U.S. Environmental Protection Agency, were analyzed for 46 pesticides and 6 pesticide metabolites. Dacthal, a pre-emergent herbicide, was detected at all five sites. Pendimethalin, also a pre-emergent, was detected at one site. The insecticides chlorpyrifos and dieldrin were detected at three sites and p,p'-DDE, a metabolite of the insecticide DDT, also was detected at three sites. SPMDs and POCIS were submerged at the upstream edge and downstream edge of the Kickapoo tribal boundaries. Both sites are downstream from the Oklahoma City metropolitan area and multiple municipal wastewater treatment plants. Extracts from the passive samplers were analyzed for 62 pesticides, 10 pesticide metabolites, 3 polychlorinated biphenyl compounds, 35

The orientation-averaged aspiration efficiency of IOM-like personal aerosol samplers mounted on bluff bodies.

Science.gov (United States)

Paik, Samuel Y; Vincent, James H

2004-01-01

This paper describes two sets of experiments that were intended to characterize the orientation-averaged aspiration efficiencies of IOM samplers mounted on rotating bluff bodies. IOM samplers were mounted on simplified, three-dimensional rectangular bluff bodies that were rotated horizontally at a constant rate. Orientation-averaged aspiration efficiencies (A360) were measured as a function of Stokes' number (St), velocity ratio (R) and dimension ratio (r). Aspiration efficiency (A) is the efficiency with which particles are transported from the ambient air into the body of a sampler, and A360 is A averaged over all orientations to the wind. St is a dimensionless variable that represents particle inertia, R is the ratio of the air velocity in the freestream and that at the plane of the sampler's entry orifice, and r is the ratio of the sampler's orifice diameter and the bluff body's width. The first set of experiments were instrumental in establishing a hierarchy of effects on orientation-averaged A. It was clear that compared to r, St had a much larger influence on A. It was also clear, however, that the effects of St were overpowered by the effects of R in many cases. As concluded in previous studies, R and St were considered the most important factors in determining A, even for A360. The second set of experiments investigated A360 of IOM samplers for a much wider range of r than examined in previous research. Two important observations were made from the experimental results. One was that the A360 of IOM samplers, as a function of St, did not change for an r-range of 0.066-0.4. This meant that an IOM sampler mounted on a near life-size mannequin would measure the same aerosol concentration as one not mounted on anything. The second observation was that the aspiration efficiency curve of the IOM sampler was close to the inhalability curve. This gave further evidence that the bluff body did not play a major role in influencing A360, as the IOM samplers, in these

WHATS-3: An improved flow-through multi-bottle fluid sampler for deep-sea geofluid research

Science.gov (United States)

Miyazaki, Junichi; Makabe, Akiko; Matsui, Yohei; Ebina, Naoya; Tsutsumi, Saki; Ishibashi, Jun-ichiro; Chen, Chong; Kaneko, Sho; Takai, Ken; Kawagucci, Shinsuke

2017-06-01

Deep-sea geofluid systems, such as hydrothermal vents and cold seeps, are key to understanding subseafloor environments of Earth. Fluid chemistry, especially, provides crucial information towards elucidating the physical, chemical and biological processes that occur in these ecosystems. To accurately assess fluid and gas properties of deep-sea geofluids, well-designed pressure-tight fluid samplers are indispensable and as such they are important assets of deep-sea geofluid research. Here, the development of a new flow-through, pressure-tight fluid sampler capable of four independent sampling events (two subsamples for liquid and gas analyses from each) is reported. This new sampler, named WHATS-3, is a new addition to the WHATS-series samplers and a major upgrade from the previous WHATS-2 sampler with improvements in sample number, valve operational time, physical robustness, and ease of maintenance. Routine laboratory-based pressure tests proved that it is suitable for operation up to 35 MPa pressure. Successful field tests of the new sampler were also carried out in five hydrothermal fields, two in Indian Ocean and three in Okinawa Trough (max. depth 3,300 m). Relations of Mg and major ion species demonstrated bimodal mixing trends between a hydrothermal fluid and seawater, confirming the high-quality of fluids sampled. The newly developed WHATS-3 sampler is well-balanced in sampling capability, field usability, and maintenance feasibility, and can serve as one of the best geofluid samplers available at present to conduct efficient research of deep-sea geofluid systems.

The suitability of the IOM foam sampler for bioaerosol sampling in Occupational Environments.

Science.gov (United States)

Haatainen, Susanna; Laitinen, Juha; Linnainmaa, Markku; Reponen, Tiina; Kalliokoski, Pentti

2010-01-01

Concurrent samples were collected with Andersen and IOM foam samplers to determine whether if the IOM foam sampler can be applied to collect culturable microorganisms. Two different kinds of aerosols were studied: peat dust in a power plant and mist from coolant fluid aerosolized during grinding of blades and rollers in a paper mill. In the power plant, the concentrations of fungi were 2-3 times higher in the IOM samples than in the Andersen samples. However, more fungal genera were identified in the latter case. The methods yielded similar concentrations of bacteria and actinobacteria in the power plant. On the other hand, the performance of the IOM foam sampler was very poor in the paper mill, where stress-sensitive gram-negative bacteria dominated; low concentration of bacteria was detected in only one IOM sample even though the concentration of bacteria often exceeded even the upper detection limit in the Andersen impactor samples. It could be concluded that the IOM foam sampler performs quite well for collecting inhalable fungi and actinobacteria. However, the Andersen sampler provides better information on fungal genera and concentrations of gram-negative bacteria. Personal sampling with the IOM foam sampler provided an important benefit in the power plant, where the concentration ratio of personal to stationary samples was much higher for bacteria than for inhalable or respirable dust.

Field Comparisons of the Elwha Bedload Sampler and an Acoustic Gravel-transport Sensor: Middle Fork of the Piedra River, Colorado, USA

Science.gov (United States)

Downing, J.; Ryan, S. E.

2001-12-01

Ten simultaneous bedload measurements were made with an Elhwa sampler and an acoustic-gravel-transport sensor (GTS) on the Middle Fork of the Piedra River in southwestern Colorado near the end of the spring freshet in water year 2001. The purpose was to compare bedload samples with acoustic measurements acquired under field conditions. Upstream of the measurement site, the river drains 86 km2 of andesite, ash flows, tuffs, and breccias in the San Juan Mountains, contributing a relatively high sediment load to the river system. The channel transitions from step-pools at high elevations to a plane bed with a slope of 0.018 in the study reach. Channel width, mean depth and bank-full velocity at the site are: 13.6 m, 0.52, and 1.5 m s-1. The D50 of the riverbed surface is 0.08 m which is 6 to 40 times larger than the D50s of the bedload samples. D16 and D84 of the bed = 0.02 and 0.21 m respectively. Water discharges from 7.3 to 9.3 m3 s-1 transported about 0.01 kg of gravel m-1 s-1 in the channel. Transport of coarse gravel (8-64 mm) ranged from 0.00063 to 0.024 kg m-1 s-1. The Elwha sampler is a portable, pressure-differential trap with a 0.2 m wide by 0.1 m high opening. The acoustic sensor is a 0.025-m wide by 0.1 m high strip of PVDF piezoelectric film connected to a signal processor and bonded to an aluminum pressure plate. When the plate is struck by stones, the GTS produces signal peaks with areas that are accurate measures of stone momentum. The GTS was calibrated with steels balls dropped on the pressure plate in still water to develop a curve of ball momentum as a function of peak areas. Based on these calibrations, the standard error of the GTS momentum estimates is 0.0017 kg m s-1. Five transects with 30 verticals, each occupied for 60 s, were completed with the sampler and GTS separated by < 1 m. Five additional verticals were occupied for about 1800 s each with the instruments separated by < 0.5 m. The trapped material was sieved and weighed and the water

Field trials of an electret based passive dust sampler in coal mines

Energy Technology Data Exchange (ETDEWEB)

Hemingway, M.A.; Brown, R.C.; Arthur, J. [Health and Safety Laboratory, Sheffield (United Kingdom)

1997-12-31

An electret-based passive dust sampler has been developed by the Health and Safety Laboratory, UK. The device consists of a small disc of electret (polymer holding a permanent electric charge) held between earthen plates, and it acts by attaching charged dust particles to itself. The device does not require a pump and its rate of sampling is independent of external air velocity, provided that the velocity exceeds a low limiting value. Experiments have been carried out in two coal mines. In each experiment two passive sampler were mounted alongside an MRE sampler at the statutory sampling point in the return roadway. Both passive samplers were mounted vertically but in one the plane of the electret was parallel to the air flow and in the other it was perpendicular. The result obtained from the first mine showed a good correlation between gravimetric estimates of dust concentration obtained with the passive samplers and respirable dust concentrations obtained with MRE. The correlation between the two sets of results at the second mine was not quite as good as those of the first, but was reasonable. In no instance was any significant difference observed between samples obtained from pairs of passive samples in different orientations. 8 refs., 5 figs., 2 tabs.

Short-term diffusive sampler for nitrogen dioxide monitoring in epidemiology

International Nuclear Information System (INIS)

Michaud, J.P.; Quackenboss, J.

1991-01-01

An automated timed exposure diffusive sampler (TEDS) for sampling nitrogen dioxide (NO 2 ) was developed for use in epidemiological studies. The TEDS sequentially exposes four passive sampling devices (PSD) by microprocessor controlled valves while a pump and air flow guide prevent sampler starvation. Two TEDS units and two portable, real-time NO 2 monitors were tested for accuracy, precision, sensitivity, and linearity of response. The accuracy of the TEDS was within 10 percent of the means of the measured values. The TEDS sensitivity was 20 to 30 ppb-hour for NO 2 . Co-location of the TEDS with a chemiluminescent NO x monitor (EPA reference method) showed a similar responses to ambient NO 2 . TEDS allows better time resolution than traditional diffusive samplers (i.e., Palmes tube) while sharing their ability to sample a variety of gases

Fluidic Sampler. Tanks Focus Area. OST Reference No. 2007

International Nuclear Information System (INIS)

1999-01-01

Problem Definition; Millions of gallons of radioactive and hazardous wastes are stored in underground tanks across the U.S. Department of Energy (DOE) complex. To manage this waste, tank operators need safe, cost-effective methods for mixing tank material, transferring tank waste between tanks, and collecting samples. Samples must be collected at different depths within storage tanks containing various kinds of waste including salt, sludge, and supernatant. With current or baseline methods, a grab sampler or a core sampler is inserted into the tank, waste is maneuvered into the sample chamber, and the sample is withdrawn from the tank. The mixing pumps in the tank, which are required to keep the contents homogeneous, must be shut down before and during sampling to prevent airborne releases. These methods are expensive, require substantial hands-on labor, increase the risk of worker exposure to radiation, and often produce nonrepresentative and unreproducible samples. How It Works: The Fluidic Sampler manufactured by AEA Technology Engineering Services, Inc., enables tank sampling to be done remotely with the mixing pumps in operation. Remote operation minimizes the risk of exposure to personnel and the possibility of spills, reducing associated costs. Sampling while the tank contents are being agitated yields consistently homogeneous, representative samples and facilitates more efficient feed preparation and evaluation of the tank contents. The above-tank portion of the Fluidic Sampler and the replacement plug and pipework that insert through the tank top are shown.

Increased concentrations of polycyclic aromatic hydrocarbons in Alpine streams during annual snowmelt: investigating effects of sampling method, site characteristics, and meteorology.

Science.gov (United States)

Shahpoury, Pourya; Hageman, Kimberly J; Matthaei, Christoph D; Alumbaugh, Robert E; Cook, Michelle E

2014-10-07

Silicone passive samplers and macroinvertebrates were used to measure time-integrated concentrations of polycyclic aromatic hydrocarbons (PAHs) in alpine streams during annual snowmelt. The three sampling sites were located near a main highway in Arthur's Pass National Park in the Southern Alps of New Zealand. A similar set of PAH congeners, composed of 2-4 rings, were found in silicone passive samplers and macroinvertebrates. The background PAH concentrations were similar at all sites, implying that proximity to the highway did not affect concentrations. In passive samplers, an increase of PAH concentrations by up to seven times was observed during snowmelt. In macroinvertebrates, the concentration changes were moderate; however, macroinvertebrate sampling did not occur during the main pulse observed in the passive samplers. The extent of vegetation in the catchment appeared to affect the concentration patterns seen at the different stream sites. A strong correlation was found between PAH concentrations in passive samplers and the amount of rainfall in the study area, indicating that the washout of contaminants from snowpack by rainfall was an important process.

Mobile dynamic passive sampling of trace organic compounds: Evaluation of sampler performance in the Danube River.

Science.gov (United States)

Vrana, Branislav; Smedes, Foppe; Allan, Ian; Rusina, Tatsiana; Okonski, Krzysztof; Hilscherová, Klára; Novák, Jiří; Tarábek, Peter; Slobodník, Jaroslav

2018-03-29

A "dynamic" passive sampling (DPS) device, consisting of an electrically driven large volume water pumping device coupled to a passive sampler exposure cell, was designed to enhance the sampling rate of trace organic compounds. The purpose of enhancing the sampling rate was to achieve sufficient method sensitivity, when the period available for sampling is limited to a few days. Because the uptake principle in the DPS remains the same as for conventionally-deployed passive samplers, free dissolved concentrations can be derived from the compound uptake using available passive sampler calibration parameters. This was confirmed by good agreement between aqueous concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) derived from DPS and conventional caged passive sampler. The DPS device enhanced sampling rates of compounds that are accumulated in samplers under water boundary layer control (WBL) more than five times compared with the conventionally deployed samplers. The DPS device was deployed from a ship cruising downstream the Danube River to provide temporally and spatially integrated concentrations. A DPS-deployed sampler with surface area of 400cm 2 can reach sampling rates up to 83Ld -1 . The comparison of three passive samplers made of different sorbents and co-deployed in the DPS device, namely silicone rubber (SR), low density polyethylene (LDPE) and SDB-RPS Empore™ disks showed a good correlation of surface specific uptake for compounds that were sampled integratively during the entire exposure period. This provided a good basis for a cross-calibration between the samplers. The good correlation of free dissolved PAHs, PCBs and HCB concentration estimates obtained using SR and LDPE confirmed that both samplers are suitable for the identification of concentration gradients and trends in the water column. We showed that the differences in calculated aqueous concentrations between sampler types

Europa Drum Sampler (EDuS), Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The main objective of the proposed work is to develop a robust and effective sample acquisition system for the Europa lander called the Europa Drum Sampler (EDuS)....

WHATS-3: An Improved Flow-Through Multi-bottle Fluid Sampler for Deep-Sea Geofluid Research

Directory of Open Access Journals (Sweden)

Junichi Miyazaki

2017-06-01

Full Text Available Deep-sea geofluid systems, such as hydrothermal vents and cold seeps, are key to understanding subseafloor environments of Earth. Fluid chemistry, especially, provides crucial information toward elucidating the physical, chemical, and biological processes that occur in these ecosystems. To accurately assess fluid and gas properties of deep-sea geofluids, well-designed pressure-tight fluid samplers are indispensable and as such they are important assets of deep-sea geofluid research. Here, the development of a new flow-through, pressure-tight fluid sampler capable of four independent sampling events (two subsamples for liquid and gas analyses from each is reported. This new sampler, named WHATS-3, is a new addition to the WHATS-series samplers and a major upgrade from the previous WHATS-2 sampler with improvements in sample number, valve operational time, physical robustness, and ease of maintenance. Routine laboratory-based pressure tests proved that it is suitable for operation up to 35 MPa pressure. Successful field tests of the new sampler were also carried out in five hydrothermal fields, two in Indian Ocean, and three in Okinawa Trough (max. depth 3,300 m. Relations of Mg and major ion species demonstrated bimodal mixing trends between a hydrothermal fluid and seawater, confirming the high quality of fluids sampled. The newly developed WHATS-3 sampler is well-balanced in sampling capability, field usability, and maintenance feasibility, and can serve as one of the best geofluid samplers available at present to conduct efficient research of deep-sea geofluid systems.

Comparative performance of two air samplers for monitoring airborne fungal propagules

Directory of Open Access Journals (Sweden)

L.G.F. Távora

2003-05-01

Full Text Available Many studies have attempted to evaluate the importance of airborne fungi in the development of invasive fungal infection, especially for immunocompromised hosts. Several kinds of instruments are available to quantitate fungal propagule levels in air. We compared the performance of the most frequently used air sampler, the Andersen sampler with six stages, with a portable one, the Reuter centrifugal sampler (RCS. A total of 84 samples were analyzed, 42 with each sampler. Twenty-eight different fungal genera were identified in samples analyzed with the Andersen instrument. In samples obtained with the RCS only seven different fungal genera were identified. The three most frequently isolated genera in samples analyzed with both devices were Penicillium, Aspergillus and Cladophialophora. In areas supplied with a high efficiency particulate air filter, fungal spore levels were usually lower when compared to areas without these filters. There was a significant correlation between total fungal propagule measurements taken with both devices on each sampling occasion (Pearson coefficient = 0.50. However, the Andersen device recovered a broader spectrum of fungi. We conclude that the RCS can be used for quantitative estimates of airborne microbiological concentrations. For qualitative studies, however, this device cannot be recommended.

MiniSipper: a new in situ water sampler for high-resolution, long-duration acid mine drainage monitoring.

Science.gov (United States)

Chapin, Thomas P; Todd, Andrew S

2012-11-15

Abandoned hard-rock mines can be a significant source of acid mine drainage (AMD) and toxic metal pollution to watersheds. In Colorado, USA, abandoned mines are often located in remote, high elevation areas that are snowbound for 7-8 months of the year. The difficulty in accessing these remote sites, especially during winter, creates challenging water sampling problems and major hydrologic and toxic metal loading events are often under sampled. Currently available automated water samplers are not well suited for sampling remote snowbound areas so the U.S. Geological Survey (USGS) has developed a new water sampler, the MiniSipper, to provide long-duration, high-resolution water sampling in remote areas. The MiniSipper is a small, portable sampler that uses gas bubbles to separate up to 250 five milliliter acidified samples in a long tubing coil. The MiniSipper operates for over 8 months unattended in water under snow/ice, reduces field work costs, and greatly increases sampling resolution, especially during inaccessible times. MiniSippers were deployed in support of an U.S. Environmental Protection Agency (EPA) project evaluating acid mine drainage inputs from the Pennsylvania Mine to the Snake River watershed in Summit County, CO, USA. MiniSipper metal results agree within 10% of EPA-USGS hand collected grab sample results. Our high-resolution results reveal very strong correlations (R(2)>0.9) between potentially toxic metals (Cd, Cu, and Zn) and specific conductivity at the Pennsylvania Mine site. The large number of samples collected by the MiniSipper over the entire water year provides a detailed look at the effects of major hydrologic events such as snowmelt runoff and rainstorms on metal loading from the Pennsylvania Mine. MiniSipper results will help guide EPA sampling strategy and remediation efforts in the Snake River watershed. Published by Elsevier B.V.

MiniSipper: A new in situ water sampler for high-resolution, long-duration acid mine drainage monitoring

Science.gov (United States)

Chapin, Thomas P.; Todd, Andrew S.

2012-01-01

Abandoned hard-rock mines can be a significant source of acid mine drainage (AMD) and toxic metal pollution to watersheds. In Colorado, USA, abandoned mines are often located in remote, high elevation areas that are snowbound for 7–8 months of the year. The difficulty in accessing these remote sites, especially during winter, creates challenging water sampling problems and major hydrologic and toxic metal loading events are often under sampled. Currently available automated water samplers are not well suited for sampling remote snowbound areas so the U.S. Geological Survey (USGS) has developed a new water sampler, the MiniSipper, to provide long-duration, high-resolution water sampling in remote areas. The MiniSipper is a small, portable sampler that uses gas bubbles to separate up to 250 five milliliter acidified samples in a long tubing coil. The MiniSipper operates for over 8 months unattended in water under snow/ice, reduces field work costs, and greatly increases sampling resolution, especially during inaccessible times. MiniSippers were deployed in support of an U.S. Environmental Protection Agency (EPA) project evaluating acid mine drainage inputs from the Pennsylvania Mine to the Snake River watershed in Summit County, CO, USA. MiniSipper metal results agree within 10% of EPA-USGS hand collected grab sample results. Our high-resolution results reveal very strong correlations (R2 > 0.9) between potentially toxic metals (Cd, Cu, and Zn) and specific conductivity at the Pennsylvania Mine site. The large number of samples collected by the MiniSipper over the entire water year provides a detailed look at the effects of major hydrologic events such as snowmelt runoff and rainstorms on metal loading from the Pennsylvania Mine. MiniSipper results will help guide EPA sampling strategy and remediation efforts in the Snake River watershed.

Chemistry of the sea surface microlayer. 1. Fabrication and testing of the sampler

Digital Repository Service at National Institute of Oceanography (India)

Singbal, S.Y.S.; Narvekar, P.V.

A screen sampler fabricated to study the sea surface microlayer (SML) has been described. The screen sampler was tested in the Mandovi estuary and adjacent waters. Physico-chemical parameters of the subsurface waters from a depth of 25 cm was also...

Evaluating the Relationship between Equilibrium Passive Sampler Uptake and Aquatic Organism Bioaccumulation (IPSW)

Science.gov (United States)

This review evaluates passive sampler uptake of hydrophobic organic contaminants (HOCs) as it relates to organism bioaccumulation in the water column and interstitial water. Fifty-five studies were found where both passive samplers and organism bioaccumulation were used to measur...

40 CFR 53.54 - Test for proper sampler operation following power interruptions.

Science.gov (United States)

2010-07-01

...) Mean sample flow rate. (i) From the certified measurements (Qref) of the test sampler flow rate... facilitate measurement of sample flow rate at the sampler downtube. (5) Means for creating an additional... pressures and temperatures used in the tests and shall be checked at zero and at least one flow rate within...

Field evaluation of a tailor-made new passive sampler for the determination of NO2 levels in ambient air.

Science.gov (United States)

Ozden, Ozlem; Dogeroglu, Tuncay

2008-07-01

This study describes the field evaluation of a tailor-made new glass passive sampler developed for the determination of NO(2), based on the collection on triethanolemine (TEA)-coated fibre filter paper. The sampler has been derived from a Palmes design. The overall uncertainty of the sampler was determined by using Griess-Saltzman ASTM D 1607 standard test method as a reference method. The agreement between the results of the passive sampler and the reference method was +/-7.90% with the correlation coefficient of 0.90. Method precision in terms of coefficient of variance (CV) for three simultaneously applied passive samplers was 8.80%. The uptake rate of NO(2) was found to be 2.49 ml/min in a very good agreement with the value calculated from theory (2.63 ml/min). Sampler detection limit was 1.99 microg/m(3) for an exposure period of 1 week and the sampler can be stored safely for a period of up to 6 weeks before exposure. A comparison of the sampler performance was conducted against a commercially available diffusion tube (Gradko diffusion tube). The results from the applied statistical paired t test indicated that there was no significant difference between the performances of two passive samplers (R (2) > 0.90). Also, another statistical comparison was carried out between the dark and transparent glass passive samplers. The results from the dark-colour sampler were higher than that from the transparent sampler (approximately 25%) during the summer season because of the possible photodegradation of NO(2)-TEA complex.

Chemical and toxicologic assessment of organic contaminants in surface water using passive samplers

Science.gov (United States)

Alvarez, D.A.; Cranor, W.L.; Perkins, S.D.; Clark, R.C.; Smith, S.B.

2008-01-01

Passive sampling methodologies were used to conduct a chemical and toxicologic assessment of organic contaminants in the surface waters of three geographically distinct agricultural watersheds. A selection of current-use agrochemicals and persistent organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides, were targeted using the polar organic chemical integrative sampler (POCIS) and the semipermeable membrane device passive samplers. In addition to the chemical analysis, the Microtox assay for acute toxicity and the yeast estrogen screen (YES) were conducted as potential assessment tools in combination with the passive samplers. During the spring of 2004, the passive samplers were deployed for 29 to 65 d at Leary Weber Ditch, IN; Morgan Creek, MD; and DR2 Drain, WA. Chemical analysis of the sampler extracts identified the agrochemicals predominantly used in those areas, including atrazine, simazine, acetochlor, and metolachlor. Other chemicals identified included deethylatrazine and deisopropylatrazine, trifluralin, fluoranthene, pyrene, cis- and trans-nonachlor, and pentachloroanisole. Screening using Microtox resulted in no acutely toxic samples. POCIS samples screened by the YES assay failed to elicit a positive estrogenic response. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Five years of nitrogen dioxide measurement with diffusion tube samplers at over 1000 sites in the UK

Science.gov (United States)

Stevenson, Ken; Bush, Tony; Mooney, Diane

In 1993, a large (>1000 monitoring sites) co-ordinated monitoring network for nitrogen dioxide, using diffusion tube samplers, was established in urban areas throughout the UK. The primary aim of this network is to assess the spatial and temporal distribution of NO 2 throughout the UK and highlight areas of high concentration which may require more detailed monitoring with automatic analysers. This paper presents a summary of the results for the first 5-years of monitoring, 1993-1997 inclusive. The network has shown that highest concentrations occur in London and urban areas of Yorkshire and Humberside and the East and West Midlands of the UK. Averaged over the whole of the UK, NO 2 concentrations have been remarkably similar for most of the 5 years, though a significant decrease was observed at urban background locations in 1997. Overall, average NO 2 concentrations during 1997 were 23 ppb at kerbside locations and 13 ppb at urban background locations. The results of the network have been used by the Department of Environment, Transport and the Regions as one of the criteria for the selection of priority areas for expansion of the UK Automatic Urban Network in recent years. Extensive quality assurance and control procedures incorporated into the network ensure that the estimated accuracy of the data is broadly comparable with the accuracy requirement for indicative monitoring specified in the EU "daughter" Directive for NO2 (±25%) . The complete dataset of results for the network can be found on the world wide web at http://www.environment.detr.gov.uk/airq/aqinfo.htm.

Field comparison of three inhalable samplers (IOM, PGP-GSP 3.5 and Button) for welding fumes.

Science.gov (United States)

Zugasti, Agurtzane; Montes, Natividad; Rojo, José M; Quintana, M José

2012-02-01

Inhalable sampler efficiency depends on the aerodynamic size of the airborne particles to be sampled and the wind speed. The aim of this study was to compare the behaviour of three personal inhalable samplers for welding fumes generated by Manual Metal Arc (MMA) and Metal Active Gas (MAG) processes. The selected samplers were the ones available in Spain when the study began: IOM, PGP-GSP 3.5 (GSP) and Button. Sampling was carried out in a welding training center that provided a homogeneous workplace environment. The static sampling assembly used allowed the placement of 12 samplers and 2 cascade impactors simultaneously. 183 samples were collected throughout 2009 and 2010. The range of welding fumes' mass concentrations was from 2 mg m(-3) to 5 mg m(-3). The pooled variation coefficients for the three inhalable samplers were less than or equal to 3.0%. Welding particle size distribution was characterized by a bimodal log-normal distribution, with MMADs of 0.7 μm and 8.2 μm. For these welding aerosols, the Button and the GSP samplers showed a similar performance (P = 0.598). The mean mass concentration ratio was 1.00 ± 0.01. The IOM sampler showed a different performance (P IOM and 0.92 ± 0.02 for GSP/IOM. This information is useful to consider the measurements accomplished by the IOM, GSP or Button samplers together, in order to assess the exposure at workplaces over time or to study exposure levels in a specific industrial activity, as welding operations.

Design and experimental evaluation of a new nanoparticle thermophoretic personal sampler

Energy Technology Data Exchange (ETDEWEB)

Azong-Wara, Nkwenti; Asbach, Christof, E-mail: asbach@iuta.de; Stahlmecke, Burkhard; Fissan, Heinz; Kaminski, Heinz [Institute of Energy and Environmental Technology (IUTA), Air Quality and Sustainable Nanotechnology Unit (Germany); Plitzko, Sabine [Federal Institute for Occupational Safety and Health (BAuA) (Germany); Bathen, Dieter; Kuhlbusch, Thomas A. J. [Institute of Energy and Environmental Technology (IUTA), Air Quality and Sustainable Nanotechnology Unit (Germany)

2013-04-15

A personal sampler that thermophoretically samples particles between a few nanometers and approximately 300 nm has been designed and first prototypes built. The thermal precipitator (TP) is designed to take samples in the breathing zone of a worker in order to determine the personal exposure to airborne nanomaterials. In the sampler, particles are deposited onto silicon substrates that can be used for consecutive electron microscopic (EM) analysis of the particle size distribution and chemical composition of the sampled particles. Due to very homogeneous size-independent particle deposition on a large portion of the substrate, representative samples can be taken for offline analysis. The experimental evaluation revealed a good general agreement with numerical simulations concerning homogeneity of the deposit and a very high correlation (R Superscript-Two = 0.98) of the deposition rate per unit area with number concentrations simultaneously measured with an SMPS for particle sizes between 14 and 305 nm. The samplers' small size of only 45 x 32 Multiplication-Sign 97 mm{sup 3} and low weight of only 140 g make it perfectly suitable as a personal sampler. The power consumption for temperature control and pump is around 1.5 W and can be easily provided by batteries.

Characterization of sediment transport upstream and downstream from Lake Emory on the Little Tennessee River near Franklin, North Carolina, 2014–15

Science.gov (United States)

Huffman, Brad A.; Hazell, William F.; Oblinger, Carolyn J.

2017-09-06

Federal, State, and local agencies and organizations have expressed concerns regarding the detrimental effects of excessive sediment transport on aquatic resources and endangered species populations in the upper Little Tennessee River and some of its tributaries. In addition, the storage volume of Lake Emory, which is necessary for flood control and power generation, has been depleted by sediment deposition. To help address these concerns, a 2-year study was conducted in the upper Little Tennessee River Basin to characterize the ambient suspended-sediment concentrations and suspended-sediment loads upstream and downstream from Lake Emory in Franklin, North Carolina. The study was conducted by the U.S. Geological Survey in cooperation with Duke Energy. Suspended-sediment samples were collected periodically, and time series of stage and turbidity data were measured from December 2013 to January 2016 upstream and downstream from Lake Emory. The stage data were used to compute time-series streamflow. Suspended-sediment samples, along with time-series streamflow and turbidity data, were used to develop regression models that were used to estimate time-series suspended-sediment concentrations for the 2014 and 2015 calendar years. These concentrations, along with streamflow data, were used to compute suspended-sediment loads. Selected suspended-sediment samples were collected for analysis of particle-size distribution, with emphasis on high-flow events. Bed-load samples were also collected upstream from Lake Emory.The estimated annual suspended-sediment loads (yields) for the upstream site for the 2014 and 2015 calendar years were 27,000 short tons (92 short tons per square mile) and 63,300 short tons (215 short tons per square mile), respectively. The annual suspended-sediment loads (yields) for the downstream site for 2014 and 2015 were 24,200 short tons (75 short tons per square mile) and 94,300 short tons (292 short tons per square mile), respectively. Overall, the

Sampling of high amounts of bioaerosols using a high-volume electrostatic field sampler

DEFF Research Database (Denmark)

Madsen, A. M.; Sharma, Anoop Kumar

2008-01-01

For studies of the biological effects of bioaerosols, large samples are necessary. To be able to sample enough material and to cover the variations in aerosol content during and between working days, a long sampling time is necessary. Recently, a high-volume transportable electrostatic field...... and 315 mg dust (net recovery of the lyophilized dust) was sampled during a period of 7 days, respectively. The sampling rates of the electrostatic field samplers were between 1.34 and 1.96 mg dust per hour, the value for the Gravikon was between 0.083 and 0.108 mg dust per hour and the values for the GSP...... samplers were between 0.0031 and 0.032 mg dust per hour. The standard deviations of replica samplings and the following microbial analysis using the electrostatic field sampler and GSP samplers were at the same levels. The exposure to dust in the straw storage was 7.7 mg m(-3) when measured...

An Introduction to the DA-T Gibbs Sampler for the Two-Parameter Logistic (2PL Model and Beyond

Directory of Open Access Journals (Sweden)

Gunter Maris

2005-01-01

Full Text Available The DA-T Gibbs sampler is proposed by Maris and Maris (2002 as a Bayesian estimation method for a wide variety of Item Response Theory (IRT models. The present paper provides an expository account of the DAT Gibbs sampler for the 2PL model. However, the scope is not limited to the 2PL model. It is demonstrated how the DA-T Gibbs sampler for the 2PL may be used to build, quite easily, Gibbs samplers for other IRT models. Furthermore, the paper contains a novel, intuitive derivation of the Gibbs sampler and could be read for a graduate course on sampling.

Determination of organochlorine pesticides in Indian coastal water using a moored in-situ sampler

Digital Repository Service at National Institute of Oceanography (India)

Sarkar, A.; SenGupta, R.

An attempt has been made to determine the concentration of different organochlorine pesticides in the seawater off the central West Coast of India using an in-situ-sampler. The Seastar in-situ sampler is an instrument, which is designed to pump...

Field monitoring of volatile organic compounds using passive air samplers in an industrial city in Japan

International Nuclear Information System (INIS)

Kume, Kazunari; Ohura, Takeshi; Amagai, Takashi; Fusaya, Masahiro

2008-01-01

Highly portable, sensitive, and selective passive air samplers were used to investigate ambient volatile organic compound (VOC) levels at multiple sampling sites in an industrial city, Fuji, Japan. We determined the spatial distributions of 27 species of VOCs in three campaigns: Mar (cold season), May (warm season), and Nov (mild season) of 2004. In all campaigns, toluene (geometric mean concentration, 14.0 μg/m 3 ) was the most abundant VOC, followed by acetaldehyde (4.76 μg/m 3 ), and formaldehyde (2.58 μg/m 3 ). The spatial distributions for certain VOCs showed characteristic patterns: high concentrations of benzene and formaldehyde were typically found along major roads, whereas high concentrations of toluene and tetrachloroethylene (PCE) were usually found near factories. The spatial distribution of PCE observed was extremely consistent with the diffusion pattern calculated from Pollutant Release and Transfer Register data and meteorological data, indicated that passive air samplers are useful for determining the sources and distributions of ambient VOCs. - Passive air samplings with hood are useful for determining the identities, sources, and distributions of ambient VOC pollutants

A novel passive water sampler for in situ sampling of antibiotics.

Science.gov (United States)

Chen, Chang-Er; Zhang, Hao; Jones, Kevin C

2012-05-01

Passive water sampling has several advantages over active methods; it provides time-integrated data, can save on time and cost compared to active methods, and yield high spatial resolution data through co-deployment of simple, cheap units. However, one problem with many sampler designs in current use is that their uptake rates for trace substances of interest are flow-rate dependent, thereby requiring calibration data and other information to enable water concentrations to be derived from the mass per sampler. However, the 'family' of samplers employing the principle of diffusive gradients in thin films (DGT) provides an in situ means of quantitatively measuring labile species in aquatic systems without field calibration. So far, this technique has only been tested and applied in inorganic substances: metals, radionuclides, nutrients, etc. Design and applications of DGT to trace organic contaminants ('o-DGT') would be of widespread interest. This study describes the laboratory testing and performance characteristics of o-DGT, with the antibiotic sulfamethoxazole (SMX) as a model compound and XAD18 as the novel binding agent. o-DGT uptake of SMX increased with time and decreased with diffusion layer thickness, confirming the principle for SMX. XAD18 showed sufficiently high capacity for SMX for routine field applications. o-DGT measurement of SMX was independent of pH (6-9) and ionic strength (0.001-0.1 M) and not affected by flow rate once above static conditions. The diffusion coefficient of SMX in the sampler was measured using an independent diffusion cell and information is presented to allow temperature correction and derivation of aqueous concentrations from deployed samplers. The potential use of o-DGT for in situ measurement of pharmaceutical antibiotics is confirmed by this study and applications are briefly discussed.

Comparison. US P-61 and Delft sediment samplers

Science.gov (United States)

Beverage, Joseph P.; Williams, David T.

1990-01-01

The Delft Bottle (DB) is a flow-through device designed by the Delft Hydraulic Laboratory (DHL), The Netherlands, to sample sand-sized sediment suspended in streams. The US P-61 sampler was designed by the Federal Interagency Sedimentation Project (FISP) at the St. Anthony Falls Hydraulic Laboratory, Minneapolis, Minnesota, to collect suspended sediment from deep, swift rivers. The results of two point-sampling tests in the United States, the Mississippi River near Vicksburg, Mississippi, in 1983 and the Colorado River near Blythe, California, in 1984, are provided in this report. These studies compare sand-transport rates, rather than total sediment-transport rates, because fine material washes through the DB sampler. In the United States, the commonly used limits for sand-sized material are 0.062 mm to 2.00 mm (Vanoni 1975).

Partitioning of organochlorine pesticides from water to polyethylene passive samplers

International Nuclear Information System (INIS)

Hale, Sarah E.; Martin, Timothy J.; Goss, Kai-Uwe; Arp, Hans Peter H.; Werner, David

2010-01-01

The mass transfer rates and equilibrium partitioning behaviour of 14 diverse organochlorine pesticides (OCP) between water and polyethylene (PE) passive samplers, cut from custom made PE sheets and commercial polyethylene plastic bags, were quantified. Overall mass transfer coefficients, k O , estimated PE membrane diffusion coefficients, D PE , and PE-water partitioning coefficients, K PE-water, are reported. In addition, the partitioning of three polycyclic aromatic hydrocarbons (PAHs) from water to PE is quantified and compared with literature values. K PE-water values agreed mostly within a factor of two for both passive samplers and also with literature values for the reference PAHs. As PE is expected to exhibit similar sorption behaviour to long-chain alkanes, PE-water partitioning coefficients were compared to hexadecane-water partitioning coefficients estimated with the SPARC online calculator, COSMOtherm and a polyparameter linear free energy relationship based on the Abraham approach. The best correlation for all compounds tested was with COSMOtherm estimated hexadecane-water partitioning coefficients. - The partitioning of organochlorine pesticides between single phase polyethylene passive samplers and water is quantified.

Passive Sampler for Measurements of Atmospheric Nitric Acid Vapor (HNO3 Concentrations

Directory of Open Access Journals (Sweden)

Andrzej Bytnerowicz

2001-01-01

Full Text Available Nitric acid (HNO3 vapor is an important nitrogenous air pollutant responsible for increasing saturation of forests with nitrogen and direct injury to plants. The USDA Forest Service and University of California researchers have developed a simple and inexpensive passive sampler for monitoring air concentrations of HNO3. Nitric acid is selectively absorbed on 47-mm Nylasorb nylon filters with no interference from particulate NO3-. Concentrations determined with the passive samplers closely corresponded with those measured with the co-located honeycomb annular denuder systems. The PVC protective caps of standardized dimensions protect nylon filters from rain and wind and allow for reliable measurements of ambient HNO3 concentrations. The described samplers have been successfully used in Sequoia National Park, the San Bernardino Mountains, and on Mammoth Mountain in California.

Uncertainties in monitoring of SVOCs in air caused by within-sampler degradation during active and passive air sampling

Science.gov (United States)

Melymuk, Lisa; Bohlin-Nizzetto, Pernilla; Prokeš, Roman; Kukučka, Petr; Přibylová, Petra; Vojta, Šimon; Kohoutek, Jiří; Lammel, Gerhard; Klánová, Jana

2017-10-01

Degradation of semivolatile organic compounds (SVOCs) occurs naturally in ambient air due to reactions with reactive trace gases (e.g., ozone, NOx). During air sampling there is also the possibility for degradation of SVOCs within the air sampler, leading to underestimates of ambient air concentrations. We investigated the possibility of this sampling artifact in commonly used active and passive air samplers for seven classes of SVOCs, including persistent organic pollutants (POPs) typically covered by air monitoring programs, as well as SVOCs of emerging concern. Two active air samplers were used, one equipped with an ozone denuder and one without, to compare relative differences in mass of collected compounds. Two sets of passive samplers were also deployed to determine the influence of degradation during longer deployment times in passive sampling. In active air samplers, comparison of the two sampling configurations suggested degradation of particle-bound polycyclic aromatic hydrocarbons (PAHs), with concentrations up to 2× higher in the denuder-equipped sampler, while halogenated POPs did not have clear evidence of degradation. In contrast, more polar, reactive compounds (e.g., organophosphate esters and current use pesticides) had evidence of losses in the sampler with denuder. This may be caused by the denuder itself, suggesting sampling bias for these compounds can be created when typical air sampling apparatuses are adapted to limit degradation. Passive air samplers recorded up to 4× higher concentrations when deployed for shorter consecutive sampling periods, suggesting that within-sampler degradation may also be relevant in passive air monitoring programs.

Heavy water leak detection using diffusion sampler

International Nuclear Information System (INIS)

Joshi, M.L.; Hussain, S.A.

1990-01-01

In the Pressurrised Heavy Water Reactors (PHWRs) detection of the sources of heavy water leaks is importent both for the purpose of radiation hazard control as well as for the reduction of escape/loss of heavy water which, is an expensive nuclear material. This paper describes an application of tritium diffusion sampler for heavy water leak detection. The diffusion sampler comprises an usual tritium counting glass vial with a special orifice. The counting vial has water vapour, deficient in HTO concentration. The HTO present outside diffuses in the vial through the orifice, gets exchanged with water of the wet filter paper kept at the bottom and the moisture in the vial atmosphere which has HTO concentration lower than that outside. This results in continuation of net movement of HTO in the vial. The exchanged tritium is counted in liquid scintillation spectrometer. The method has a sensitivity of 10000 dpm/DAC-h. (author). 2 figs., 2 ta bs

Mechanical reliability evaluation of alternate motors for use in a radioiodine air sampler

International Nuclear Information System (INIS)

Bird, S.K.; Huchton, R.L.; Motes, B.G.

1984-03-01

Detailed mechanical reliability studies of two alternate motors identified for use in the BNL Air Sampler wer conducted. The two motor types were obtained from Minnesota Electric Technology, Incorporated (MET) and TCS Industries (TCSI). Planned testing included evaluation of motor lifetimes and motor operability under different conditions of temperature, relative humidity, simulated rainfall, and dusty air. The TCSI motors were not lifetime tested due to their poor performance during the temperature/relative humidity tests. While operation on alternating current was satisfactory, on direct current only one of five TCSI motors completed all environmental testing. The MET motors had average lifetimes of 47 hours, 97 hours, and 188 hours, respectively, and exhibited satisfactory operation under all environmental test conditions. Therefore, the MET motor appears to be the better candidate motor for use in the BNL Air Sampler. However, because of the relatively high cost of purchasing and incorporating the MET motor into the BNL Air Sampler System, it is recommended that commercial air sampler systems be evaluated for use instead of the BNL system

POSTRANSLATIONAL MODIFICATIONS OF P53: UPSTREAM SIGNALING PATHWAYS.

Energy Technology Data Exchange (ETDEWEB)

ANDERSON,C.W.APPELLA,E.

2003-10-23

The p53 tumor suppressor is a tetrameric transcription factor that is posttranslational modified at >20 different sites by phosphorylation, acetylation, or sumoylation in response to various cellular stress conditions. Specific posttranslational modifications, or groups of modifications, that result from the activation of different stress-induced signaling pathways are thought to modulate p53 activity to regulate cell fate by inducing cell cycle arrest, apoptosis, or cellular senescence. Here we review recent progress in characterizing the upstream signaling pathways whose activation in response to various genotoxic and non-genotoxic stresses result in p53 posttranslational modifications.

The giant mottled eel, Anguilla marmorata, uses blue-shifted rod photoreceptors during upstream migration.

Science.gov (United States)

Wang, Feng-Yu; Fu, Wen-Chun; Wang, I-Li; Yan, Hong Young; Wang, Tzi-Yuan

2014-01-01

Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of A. marmorata during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The λmax of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2) revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292) and four putative (S124, V189, V286, I290) tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice.

A carbon monoxide passive sampler: Research and development needs

Energy Technology Data Exchange (ETDEWEB)

Traynor, G.W.; Apte, M.G.; Diamond, R.C.; Woods, A.L.

1991-11-01

In rare instances, carbon monoxide (CO) levels in houses can reach dangerously high concentrations, causing adverse health effects ranging from mild headaches to, under extreme conditions, death. Hundreds of fatal accidental carbon monoxide poisonings occur each year primarily due to the indoor operation of motor vehicles, the indoor use of charcoal for cooking, the operation of malfunctioning vented and unvented combustion appliances, and the misuse combustion appliances. Because there is a lack of simple, inexpensive, and accurate field sampling instrumentation, it is difficult for gas utilities and researchers to conduct field research studies designed to quantify the concentrations of CO in residences. Determining the concentration of CO in residences is the first step towards identifying the high risk appliances and high-CO environments which pose health risks. Thus, there exists an urgent need to develop and field-validate a CO-quantifying technique suitable for affordable field research. A CO passive sampler, if developed, could fulfill these requirements. Existing CO monitoring techniques are discussed as well as three potential CO-detection methods for use in a CO passive sampler. Laboratory and field research needed for the development and validation of an effective and cost-efficient CO passive sampler are also discussed.

Wind tunnel evaluation of the RAAMP sampler. Final report

International Nuclear Information System (INIS)

Vanderpool, R.W.; Peters, T.M.

1994-11-01

Wind tunnel tests of the Department of Energy RAAMP (Radioactive Atmospheric Aerosol Monitoring Program) monitor have been conducted at wind speeds of 2 km/hr and 24 km/hr. The RAAMP sampler was developed based on three specific performance objectives: (1) meet EPA PM10 performance criteria, (2) representatively sample and retain particles larger than 10 microm for later isotopic analysis, (3) be capable of continuous, unattended operation for time periods up to 2 months. In this first phase of the evaluation, wind tunnel tests were performed to evaluate the sampler as a potential candidate for EPA PM10 reference or equivalency status. As an integral part of the project, the EPA wind tunnel facility was fully characterized at wind speeds of 2 km/hr and 24 km/hr in conjunction with liquid test aerosols of 10 microm aerodynamic diameter. Results showed that the facility and its operating protocols met or exceeded all 40 CFR Part 53 acceptance criteria regarding PM10 size-selective performance evaluation. Analytical procedures for quantitation of collected mass deposits also met 40 CFR Part 53 criteria. Modifications were made to the tunnel's test section to accommodate the large dimensions of the RAAMP sampler's instrument case

A novel enhanced diffusion sampler for collecting gaseous pollutants without air agitation.

Science.gov (United States)

Pan, Xuelian; Zhuo, Shaojie; Zhong, Qirui; Chen, Yuanchen; Du, Wei; Cheng, Hefa; Wang, Xilong; Zeng, Eddy Y; Xing, Baoshan; Tao, Shu

2018-03-06

A novel enhanced diffusion sampler for collecting gaseous phase polycyclic aromatic hydrocarbons (PAHs) without air agitation is proposed. The diffusion of target compounds into a sampling chamber is facilitated by continuously purging through a closed-loop flow to create a large concentration difference between the ambient air and the air in the sampling chamber. A glass-fiber filter-based prototype was developed. It was demonstrated that the device could collect gaseous PAHs at a much higher rate (1.6 ± 1.4 L/min) than regular passive samplers, while the ambient air is not agitated. The prototype was also tested in both the laboratory and field for characterizing the concentration gradients over a short distance from the soil surface. The sampler has potential to be applied in other similar situations to characterize the concentration profiles of other chemicals.

Use of dust fall filters as passive samplers for metal concentrations in air for communities near contaminated mine tailings.

Science.gov (United States)

Beamer, P I; Sugeng, A J; Kelly, M D; Lothrop, N; Klimecki, W; Wilkinson, S T; Loh, M

2014-05-01

Mine tailings are a source of metal exposures in many rural communities. Multiple air samples are necessary to assess the extent of exposures and factors contributing to these exposures. However, air sampling equipment is costly and requires trained personnel to obtain measurements, limiting the number of samples that can be collected. Simple, low-cost methods are needed to allow for increased sample collection. The objective of our study was to assess if dust fall filters can serve as passive air samplers and be used to characterize potential exposures in a community near contaminated mine tailings. We placed filters in cylinders, concurrently with active indoor air samplers, in 10 occupied homes. We calculated an estimated flow rate by dividing the mass on each dust fall filter by the bulk air concentration and the sampling duration. The mean estimated flow rate for dust fall filters was significantly different during sampling periods with precipitation. The estimated flow rate was used to estimate metal concentration in the air of these homes, as well as in 31 additional homes in another rural community impacted by contaminated mine tailings. The estimated air concentrations had a significant linear association with the measured air concentrations for beryllium, manganese and arsenic (p passive air sampler is a simple low-cost method to assess potential exposures near contaminated mining sites.

Development of a sensitive passive sampler using indigotrisulfonate for the determination of tropospheric ozone.

Science.gov (United States)

Garcia, Gabriel; Allen, Andrew George; Cardoso, Arnaldo Alves

2010-06-01

A new sampling and analytical design for measurement of ambient ozone is presented. The procedure is based on ozone absorption and decoloration (at 600 nm) of indigotrisulfonate dye, where ozone adds itself across the carbon-carbon double bond of the indigo. A mean relative standard deviation of 8.6% was obtained using samplers exposed in triplicate, and a correlation coefficient (r) of 0.957 was achieved in parallel measurements using the samplers and a commercial UV ozone instrument. The devices were evaluated in a measurement campaign, mapping spatial and temporal trends of ozone concentrations in a region of southeast Brazil strongly influenced by seasonal agricultural biomass burning, with associated emissions of ozone precursors. Ozone concentrations were highest in rural areas and lowest at an urban site, due to formation during downwind transport and short-term depletion due to titration with nitric oxide. Ozone concentrations showed strong seasonal trends, due to the influences of precursor emissions, relative humidity and solar radiation intensity. Advantages of the technique include ease and speed of use, the ready availability of components, and excellent sensitivity. Achievable temporal resolution of ozone concentrations is 8 hours at an ambient ozone concentration of 3.8 ppb, or 2 hours at a concentration of 15.2 ppb.

Global evaluation and calibration of a passive air sampler for gaseous mercury

Science.gov (United States)

McLagan, David S.; Mitchell, Carl P. J.; Steffen, Alexandra; Hung, Hayley; Shin, Cecilia; Stupple, Geoff W.; Olson, Mark L.; Luke, Winston T.; Kelley, Paul; Howard, Dean; Edwards, Grant C.; Nelson, Peter F.; Xiao, Hang; Sheu, Guey-Rong; Dreyer, Annekatrin; Huang, Haiyong; Hussain, Batual Abdul; Lei, Ying D.; Tavshunsky, Ilana; Wania, Frank

2018-04-01

Passive air samplers (PASs) for gaseous mercury (Hg) were deployed for time periods between 1 month and 1 year at 20 sites across the globe with continuous atmospheric Hg monitoring using active Tekran instruments. The purpose was to evaluate the accuracy of the PAS vis-à-vis the industry standard active instruments and to determine a sampling rate (SR; the volume of air stripped of gaseous Hg per unit of time) that is applicable across a wide range of conditions. The sites spanned a wide range of latitudes, altitudes, meteorological conditions, and gaseous Hg concentrations. Precision, based on 378 replicated deployments performed by numerous personnel at multiple sites, is 3.6 ± 3.0 %1, confirming the PAS's excellent reproducibility and ease of use. Using a SR previously determined at a single site, gaseous Hg concentrations derived from the globally distributed PASs deviate from Tekran-based concentrations by 14.2 ± 10 %. A recalibration using the entire new data set yields a slightly higher SR of 0.1354 ± 0.016 m3 day-1. When concentrations are derived from the PAS using this revised SR the difference between concentrations from active and passive sampling is reduced to 8.8 ± 7.5 %. At the mean gaseous Hg concentration across the study sites of 1.54 ng m-3, this represents an ability to resolve concentrations to within 0.13 ng m-3. Adjusting the sampling rate to deployment specific temperatures and wind speeds does not decrease the difference in active-passive concentration further (8.7 ± 5.7 %), but reduces its variability by leading to better agreement in Hg concentrations measured at sites with very high and very low temperatures and very high wind speeds. This value (8.7 ± 5.7 %) represents a conservative assessment of the overall uncertainty of the PAS due to inherent uncertainties of the Tekran instruments. Going forward, the recalibrated SR adjusted for temperature and wind speed should be used, especially if conditions are highly variable or

The use of passive samplers for monitoring polycyclic aromatic hydrocarbons in ambient air

International Nuclear Information System (INIS)

Jacob, J.; Grimmer, G.; Hildebrandt, A.

1993-01-01

In this study polycyclic aromatic hydrocarbon (PAH) concentrations of ambient air are compared to those present in leaves, spruce sprouts and in the corresponding soil used as passive samplers. Marked profile alterations were detected in various soil horizons with increasing relative concentrations of higher boiling and decreasing relative concentrations of lower boiling PAH with depth. There is no direct correlation between the absolute PAH masses found in air samples and those collected by passive samplers or detected in corresponding soil samples. Even the PAH profiles differ significantly: they can, however, be correlated by introducing PAH - and sampler-specific factors. The PAH profiles appear to indicate that coal combustion mostly contributes to the PAH air pollution in the FRG. The time course of the concentration of benzo(a)pyrene and benzo(e)pyrene during the past seven years as measured with spruce sprouts as biological passive sampler indicate a significant decrease of the PAH concentration (by a factor of two) in the FRG. First measurements in a clean air area of the Eastern part of the FRG exhibited up to ten times higher PAH concentrations than found in comparable areas of the western part of the country

The giant mottled eel, Anguilla marmorata, uses blue-shifted rod photoreceptors during upstream migration.

Directory of Open Access Journals (Sweden)

Feng-Yu Wang

Full Text Available Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of A. marmorata during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The λmax of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2 revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292 and four putative (S124, V189, V286, I290 tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice.

Evaluation of physical sampling efficiency for cyclone-based personal bioaerosol samplers in moving air environments.

Science.gov (United States)

Su, Wei-Chung; Tolchinsky, Alexander D; Chen, Bean T; Sigaev, Vladimir I; Cheng, Yung Sung

2012-09-01

The need to determine occupational exposure to bioaerosols has notably increased in the past decade, especially for microbiology-related workplaces and laboratories. Recently, two new cyclone-based personal bioaerosol samplers were developed by the National Institute for Occupational Safety and Health (NIOSH) in the USA and the Research Center for Toxicology and Hygienic Regulation of Biopreparations (RCT & HRB) in Russia to monitor bioaerosol exposure in the workplace. Here, a series of wind tunnel experiments were carried out to evaluate the physical sampling performance of these two samplers in moving air conditions, which could provide information for personal biological monitoring in a moving air environment. The experiments were conducted in a small wind tunnel facility using three wind speeds (0.5, 1.0 and 2.0 m s(-1)) and three sampling orientations (0°, 90°, and 180°) with respect to the wind direction. Monodispersed particles ranging from 0.5 to 10 μm were employed as the test aerosols. The evaluation of the physical sampling performance was focused on the aspiration efficiency and capture efficiency of the two samplers. The test results showed that the orientation-averaged aspiration efficiencies of the two samplers closely agreed with the American Conference of Governmental Industrial Hygienists (ACGIH) inhalable convention within the particle sizes used in the evaluation tests, and the effect of the wind speed on the aspiration efficiency was found negligible. The capture efficiencies of these two samplers ranged from 70% to 80%. These data offer important information on the insight into the physical sampling characteristics of the two test samplers.

Development and evaluation of an ultrasonic personal aerosol sampler.

Science.gov (United States)

Volckens, J; Quinn, C; Leith, D; Mehaffy, J; Henry, C S; Miller-Lionberg, D

2017-03-01

Assessing personal exposure to air pollution has long proven challenging due to technological limitations posed by the samplers themselves. Historically, wearable aerosol monitors have proven to be expensive, noisy, and burdensome. The objective of this work was to develop a new type of wearable monitor, an ultrasonic personal aerosol sampler (UPAS), to overcome many of the technological limitations in personal exposure assessment. The UPAS is a time-integrated monitor that features a novel micropump that is virtually silent during operation. A suite of onboard environmental sensors integrated with this pump measure and record mass airflow (0.5-3.0 L/min, accurate within 5%), temperature, pressure, relative humidity, light intensity, and acceleration. Rapid development of the UPAS was made possible through recent advances in low-cost electronics, open-source programming platforms, and additive manufacturing for rapid prototyping. Interchangeable cyclone inlets provided a close match to the EPA PM 2.5 mass criterion (within 5%) for device flows at either 1.0 or 2.0 L/min. Battery life varied from 23 to 45 hours depending on sample flow rate and selected filter media. Laboratory tests of the UPAS prototype demonstrate excellent agreement with equivalent federal reference method samplers for gravimetric analysis of PM 2.5 across a broad range of concentrations. © 2016 The Authors. Indoor Air published by John Wiley & Sons Ltd.

Performance Evaluation of Automated Passive Capillary Sampler for Estimating Water Drainage in the Vadose Zone

Science.gov (United States)

Passive capillary samplers (PCAPs) are widely used to monitor, measure and sample drainage water under saturated and unsaturated soil conditions in the vadose zone. The objective of this study was to evaluate the performance and accuracy of automated passive capillary sampler for estimating drainage...

Engineering Task Plan for Preparing the Type 4 In Situ Vapor Samplers (ISVS) for Use

International Nuclear Information System (INIS)

BOGER, R.M.

2000-01-01

The DOE has identified a need to sample vapor space and exhaust ducts of several waste tanks The In-Situ Vapor Sampling (ISVS) Type IV vapor sampling cart has been identified as the appropriate monitoring tool. The ISVS carts have been out of service for a number of years. This ETP outlines the work to be performed to ready the type IV gas sampler for operation Characterization Engineering will evaluate the Type IV gas sampler carts to determine their state of readiness and will proceed to update procedures and equipment documentation to make the sampler operationally acceptable

HTO/HT discriminating samplers constructed for the french experiment on the environmental behaviour of HT

International Nuclear Information System (INIS)

Ogram, G.L.

1988-12-01

The French Experiment on Environmental Tritium Behaviour was a field experiment carried out to determine the rate of formation of atmospheric HTO from a release of HT to the natural environment. The Canadian Fusion Fuels Technology Project and Ontario Hydro contributed to the project by supplying HTO/HT-discriminating, atmospheric tritium samplers. Each sampler consisted of a molecular-sieve trap to capture HTO followed by a Pd-impregnated molecular-sieve trap to oxidise and collect HT from the same air stream. This method was selected as it provided high sensitivity over short sampling periods and was convenient for field use. Laboratory tests indicated that this system measured HT concentrations reliably, but only achieved limited discrimination between HT and HTO at HTO/HT concentration ratios below 10 -2 to 10 -3 . Small cold traps were therefore operated during the French experiment in addition to the molecular-sieve samplers exhibited much improved discrimination in the field (approaching 10 4 ), possibly due to higher sampling flow rates than used in the laboratory. These results demonstrate that care should be taken in using desiccant-based, HTO/HT-discriminating samplers when the HT concentration is much higher than HTO concentration, and suggest the need to systematically characterize and perhaps improve the performance of discriminating samplers at low HTO/HT ratios

Isokinetic sampler; Amostrador isocinetico

Energy Technology Data Exchange (ETDEWEB)

Andrade, Luis Cesar C. de; Santos, Antonio Carlos dos [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil); Barrio, Lara B.A. del [AZ Armaturen do Brasil Ltda., Itatiba, SP (Brazil); Silva, Claudio B. da C. e; Silva, Ricardo R. da [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

2005-07-01

The Center of Research Leopoldo A. Miguez de Melo - CENPES - in association with AZ Armaturen Company do Brasil and TRANSPETRO developed and tested an Isokinetic sampler. This work presents the sampling principles and the results and performance of the tests realized in the 'Sitio de Testes de Atalaia' and in one of the terminals of bunker transfer of TRANSPETRO - 'Terminal Aquaviario da Baia de Guanabara'. In the 'Sitio de Testes' the products used were oil and water with BSW from 5% to 97% and in the terminal were tested samplings of bunker with ranges viscosities between (MF 180 to 380). (author)

Observations on persistent organic pollutants in indoor and outdoor air using passive polyurethane foam samplers

Science.gov (United States)

Bohlin, Pernilla; Jones, Kevin C.; Tovalin, Horacio; Strandberg, Bo

Air quality data of persistent organic pollutants (POPs) indoors and outdoors are sparse or lacking in several parts of the world, often hampered by the cost and inconvenience of active sampling techniques. Cheap and easy passive air sampling techniques are therefore helpful for reconnaissance surveys. As a part of the Megacity Initiative: Local and Global Research Observations (MILAGRO) project in Mexico City Metropolitan Area in 2006, a range of POPs (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs)) were analyzed in polyurethane foam (PUF) disks used as passive samplers in indoor and outdoor air. Results were compared to those from samplers deployed simultaneously in Gothenburg (Sweden) and Lancaster (United Kingdom). Using sampling rates suggested in the literature, the sums of 13 PAHs in the different sites were estimated to be 6.1-180 ng m -3, with phenanthrene as the predominant compound. Indoor PAH levels tended to be higher in Gothenburg and outdoor levels higher in Mexico City. The sum of PCBs ranged 59-2100 ng m -3, and seemed to be highest indoors in Gothenburg and Lancaster. PBDE levels (sum of seven) ranged 0.68-620 ng m -3, with the highest levels found in some indoor locations. OCPs (i.e. DDTs, HCHs, and chlordanes) were widely dispersed both outdoors and indoors at all three studied areas. In Gothenburg all POPs tended to be higher indoors than outdoors, while indoor and outdoor levels in Mexico City were similar. This could be due to the influence of indoor and outdoor sources, air exchange rates, and lifestyle factors. The study demonstrates how passive samplers can provide quick and cheap reconnaissance data simultaneously at many locations which can shed light on sources and other factors influencing POP levels in air, especially for the gaseous fractions.

Validation of Ogawa passive samplers for the determination of gaseous ammonia concentrations in agricultural settings

Science.gov (United States)

Roadman, M. J.; Scudlark, J. R.; Meisinger, J. J.; Ullman, W. J.

The Ogawa passive sampler (Ogawa USA, Pompano Beach, Florida) is a useful tool for monitoring atmospheric ammonia (NH 3(g)) concentrations and assessing the effects of agricultural waste management practices on NH 3(g) emissions. The Ogawa sampler, with filter-discs impregnated with citric acid, was used to trap and determine NH 3(g) concentrations in a variety of agricultural settings. A wide range of NH 3(g) concentrations can be monitored by varying the sampler exposure time, provided that no more than ˜10 μg of NH 3-N are adsorbed on the acid-coated filters. Concentrations less than 1 μg NH 3-N m -3 can be detected using long deployments (⩽14 days), while concentrations as great as 10 mg NH 3-N m -3 may be determined in very short (e.g. 5 min) deployments. Reproducibility ranged from 5% to 10% over the range of concentrations studied and passive determinations of NH 3(g) were similar to those determined using dilute-acid gas scrubbers. Background levels of NH 3(g) at a non-agricultural site in southern Delaware were typically <1 μg NH 3-N m -3. The air entering a chicken house was 10 μg NH 3-N m -3, reflecting the background levels in agricultural settings in this region. Within the house, concentrations ⩽8.5 mg NH 3-N m -3 were observed, reflecting the high rates of NH 3(g) emission from chicken excreta. Using measured NH 3(g) concentrations and poultry house ventilation rates, we estimate that each broiler grown to production size over 6 weeks contributes approximately 19±3 g of NH 3-N to the atmosphere, a value consistent with other published results.

Development of a new passive sampler based on diffusive milligel beads for copper analysis in water

International Nuclear Information System (INIS)

Perez, M.; Reynaud, S.; Lespes, G.; Potin-Gautier, M.; Mignard, E.; Chéry, P.; Schaumlöffel, D.; Grassl, B.

2015-01-01

A new passive sampler was designed and characterized for the determination of free copper ion (Cu 2+ ) concentration in aqueous solution. Each sampling device was composed of a set of about 30 diffusive milligel (DMG) beads. Milligel beads with incorporated cation exchange resin (Chelex) particles were synthetized using an adapted droplet-based millifluidic process. Beads were assumed to be prolate spheroids, with a diameter of 1.6 mm and an anisotropic factor of 1.4. The milligel was controlled in chemical composition of hydrogel (monomer, cross-linker, initiator and Chelex concentration) and characterized in pore size. Two types of sampling devices were developed containing 7.5% and 15% of Chelex, respectively, and 6 nm pore size. The kinetic curves obtained demonstrated the accumulation of copper in the DMG according to the process described in the literature as absorption (and/or adsorption) and release following the Fick's first law of diffusion. For their use in water monitoring, the typical physico-chemical characteristics of the samplers, i.e. the mass-transfer coefficient (k 0 ) and the sampler-water partition coefficient (K sw ), were determined based on a static exposure design. In order to determine the copper concentration in the samplers after their exposure, a method using DMG bead digestion combined to Inductively Coupled Plasma – Atomic Emission Spectrometry (ICP-AES) analysis was developed and optimized. The DMG devices proved to be capable to absorb free copper ions from an aqueous solution, which could be accurately quantified with a mean recovery of 99% and a repeatability of 7% (mean relative uncertainty). - Highlights: • Controlled geometry of new passive sampler with ellipsoidal shape. • Original manufacturing process based on droplet-based millifluidic device. • Pore size characterization of the sampler. • Mass-transfer and sampler-water partitioning coefficients by static exposure experiments

Development of a new passive sampler based on diffusive milligel beads for copper analysis in water

Energy Technology Data Exchange (ETDEWEB)

Perez, M.; Reynaud, S.; Lespes, G.; Potin-Gautier, M. [Université de Pau et des Pays de l’Adour/CNRS UMR IPREM 5254, Hélioparc, 2 av. du Président Angot, 64053 Pau (France); Mignard, E. [CNRS-Solvay-Université Bordeaux, UMR5258, Laboratoire du Futur, 178 Avenue du Dr. A. Schweitzer, 33608 Pessac Cedex (France); Chéry, P. [Bordeaux Science Agro, 1 cours du Général De Gaulle, Gradignan, 33175 (France); Schaumlöffel, D. [Université de Pau et des Pays de l’Adour/CNRS UMR IPREM 5254, Hélioparc, 2 av. du Président Angot, 64053 Pau (France); Grassl, B., E-mail: bruno.grassl@univ-pau.fr [Université de Pau et des Pays de l’Adour/CNRS UMR IPREM 5254, Hélioparc, 2 av. du Président Angot, 64053 Pau (France)

2015-08-26

A new passive sampler was designed and characterized for the determination of free copper ion (Cu{sup 2+}) concentration in aqueous solution. Each sampling device was composed of a set of about 30 diffusive milligel (DMG) beads. Milligel beads with incorporated cation exchange resin (Chelex) particles were synthetized using an adapted droplet-based millifluidic process. Beads were assumed to be prolate spheroids, with a diameter of 1.6 mm and an anisotropic factor of 1.4. The milligel was controlled in chemical composition of hydrogel (monomer, cross-linker, initiator and Chelex concentration) and characterized in pore size. Two types of sampling devices were developed containing 7.5% and 15% of Chelex, respectively, and 6 nm pore size. The kinetic curves obtained demonstrated the accumulation of copper in the DMG according to the process described in the literature as absorption (and/or adsorption) and release following the Fick's first law of diffusion. For their use in water monitoring, the typical physico-chemical characteristics of the samplers, i.e. the mass-transfer coefficient (k{sub 0}) and the sampler-water partition coefficient (K{sub sw}), were determined based on a static exposure design. In order to determine the copper concentration in the samplers after their exposure, a method using DMG bead digestion combined to Inductively Coupled Plasma – Atomic Emission Spectrometry (ICP-AES) analysis was developed and optimized. The DMG devices proved to be capable to absorb free copper ions from an aqueous solution, which could be accurately quantified with a mean recovery of 99% and a repeatability of 7% (mean relative uncertainty). - Highlights: • Controlled geometry of new passive sampler with ellipsoidal shape. • Original manufacturing process based on droplet-based millifluidic device. • Pore size characterization of the sampler. • Mass-transfer and sampler-water partitioning coefficients by static exposure experiments.

Bayesian analysis for exponential random graph models using the adaptive exchange sampler

KAUST Repository

Jin, Ick Hoon

2013-01-01

Exponential random graph models have been widely used in social network analysis. However, these models are extremely difficult to handle from a statistical viewpoint, because of the existence of intractable normalizing constants. In this paper, we consider a fully Bayesian analysis for exponential random graph models using the adaptive exchange sampler, which solves the issue of intractable normalizing constants encountered in Markov chain Monte Carlo (MCMC) simulations. The adaptive exchange sampler can be viewed as a MCMC extension of the exchange algorithm, and it generates auxiliary networks via an importance sampling procedure from an auxiliary Markov chain running in parallel. The convergence of this algorithm is established under mild conditions. The adaptive exchange sampler is illustrated using a few social networks, including the Florentine business network, molecule synthetic network, and dolphins network. The results indicate that the adaptive exchange algorithm can produce more accurate estimates than approximate exchange algorithms, while maintaining the same computational efficiency.

Sampling trace organic compounds in water: a comparison of a continuous active sampler to continuous passive and discrete sampling methods.

Science.gov (United States)

Coes, Alissa L; Paretti, Nicholas V; Foreman, William T; Iverson, Jana L; Alvarez, David A

2014-03-01

A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19-23 h for CLAM and 29 days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method. Published by Elsevier B.V.

Sampling trace organic compounds in water: a comparison of a continuous active sampler to continuous passive and discrete sampling methods

Science.gov (United States)

Coes, Alissa L.; Paretti, Nicholas V.; Foreman, William T.; Iverson, Jana L.; Alvarez, David A.

2014-01-01

A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19–23 h for CLAM and 29 days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method.

Hayabusa2 Sampler: Collection of Asteroidal Surface Material

Science.gov (United States)

Sawada, Hirotaka; Okazaki, Ryuji; Tachibana, Shogo; Sakamoto, Kanako; Takano, Yoshinori; Okamoto, Chisato; Yano, Hajime; Miura, Yayoi; Abe, Masanao; Hasegawa, Sunao; Noguchi, Takaaki

2017-07-01

Japan Aerospace Exploration Agency (JAXA) launched the asteroid exploration probe "Hayabusa2" in December 3rd, 2014, following the 1st Hayabusa mission. With technological and scientific improvements from the Hayabusa probe, we plan to visit the C-type asteroid 162137 Ryugu (1999 JU3), and to sample surface materials of the C-type asteroid that is likely to be different from the S-type asteroid Itokawa and contain more pristine materials, including organic matter and/or hydrated minerals, than S-type asteroids. We developed the Hayabusa2 sampler to collect a minimum of 100 mg of surface samples including several mm-sized particles at three surface locations without any severe terrestrial contamination. The basic configuration of the sampler design is mainly as same as the 1st Hayabusa (Yano et al. in Science, 312(5778):1350-1353, 2006), with several minor but important modifications based on lessons learned from the Hayabusa to fulfill the scientific requirements and to raise the scientific value of the returned samples.

Effects of Hardness on Pintle Rod Performance in the Universal and Retained Gas Samplers

International Nuclear Information System (INIS)

BOGER, R.M.

1999-01-01

Interaction between hardness of the pintle rods and the retainer rings used in the core samplers is investigated. It is found that ordinary Rockwell C measurements are not sufficient and superficial hardness instruments are recommended to verify hardness since in-production hardness of pintle rods is found to vary widely and probably leads to some premature release of pistons in samplers

Retained Gas Sampler Calibration and Simulant Tests

Energy Technology Data Exchange (ETDEWEB)

CRAWFORD, B.A.

2000-01-05

This test plan provides a method for calibration of the retained gas sampler (RGS) for ammonia gas analysis. Simulant solutions of ammonium hydroxide at known concentrations will be diluted with isotopically labeled 0.04 M ammonium hydroxide solution. Sea sand solids will also be mixed with ammonium hydroxide solution and diluent to determine the accuracy of the system for ammonia gas analysis.

Retained Gas Sampler Calibration and Simulant Tests

International Nuclear Information System (INIS)

CRAWFORD, B.A.

2000-01-01

This test plan provides a method for calibration of the retained gas sampler (RGS) for ammonia gas analysis. Simulant solutions of ammonium hydroxide at known concentrations will be diluted with isotopically labeled 0.04 M ammonium hydroxide solution. Sea sand solids will also be mixed with ammonium hydroxide solution and diluent to determine the accuracy of the system for ammonia gas analysis

A Bayesian Sampler for Optimization of Protein Domain Hierarchies

Science.gov (United States)

2014-01-01

Abstract The process of identifying and modeling functionally divergent subgroups for a specific protein domain class and arranging these subgroups hierarchically has, thus far, largely been done via manual curation. How to accomplish this automatically and optimally is an unsolved statistical and algorithmic problem that is addressed here via Markov chain Monte Carlo sampling. Taking as input a (typically very large) multiple-sequence alignment, the sampler creates and optimizes a hierarchy by adding and deleting leaf nodes, by moving nodes and subtrees up and down the hierarchy, by inserting or deleting internal nodes, and by redefining the sequences and conserved patterns associated with each node. All such operations are based on a probability distribution that models the conserved and divergent patterns defining each subgroup. When we view these patterns as sequence determinants of protein function, each node or subtree in such a hierarchy corresponds to a subgroup of sequences with similar biological properties. The sampler can be applied either de novo or to an existing hierarchy. When applied to 60 protein domains from multiple starting points in this way, it converged on similar solutions with nearly identical log-likelihood ratio scores, suggesting that it typically finds the optimal peak in the posterior probability distribution. Similarities and differences between independently generated, nearly optimal hierarchies for a given domain help distinguish robust from statistically uncertain features. Thus, a future application of the sampler is to provide confidence measures for various features of a domain hierarchy. PMID:24494927

Global evaluation and calibration of a passive air sampler for gaseous mercury

Directory of Open Access Journals (Sweden)

D. S. McLagan

2018-04-01

Full Text Available Passive air samplers (PASs for gaseous mercury (Hg were deployed for time periods between 1 month and 1 year at 20 sites across the globe with continuous atmospheric Hg monitoring using active Tekran instruments. The purpose was to evaluate the accuracy of the PAS vis-à-vis the industry standard active instruments and to determine a sampling rate (SR; the volume of air stripped of gaseous Hg per unit of time that is applicable across a wide range of conditions. The sites spanned a wide range of latitudes, altitudes, meteorological conditions, and gaseous Hg concentrations. Precision, based on 378 replicated deployments performed by numerous personnel at multiple sites, is 3.6 ± 3.0 %1, confirming the PAS's excellent reproducibility and ease of use. Using a SR previously determined at a single site, gaseous Hg concentrations derived from the globally distributed PASs deviate from Tekran-based concentrations by 14.2 ± 10 %. A recalibration using the entire new data set yields a slightly higher SR of 0.1354 ± 0.016 m3 day−1. When concentrations are derived from the PAS using this revised SR the difference between concentrations from active and passive sampling is reduced to 8.8 ± 7.5 %. At the mean gaseous Hg concentration across the study sites of 1.54 ng m−3, this represents an ability to resolve concentrations to within 0.13 ng m−3. Adjusting the sampling rate to deployment specific temperatures and wind speeds does not decrease the difference in active–passive concentration further (8.7 ± 5.7 %, but reduces its variability by leading to better agreement in Hg concentrations measured at sites with very high and very low temperatures and very high wind speeds. This value (8.7 ± 5.7 % represents a conservative assessment of the overall uncertainty of the PAS due to inherent uncertainties of the Tekran instruments. Going forward, the recalibrated SR adjusted for temperature and wind speed

iDNA screening: Disease vectors as vertebrate samplers.

Science.gov (United States)

Kocher, Arthur; de Thoisy, Benoit; Catzeflis, François; Valière, Sophie; Bañuls, Anne-Laure; Murienne, Jérôme

2017-11-01

In the current context of global change and human-induced biodiversity decline, there is an urgent need for developing sampling approaches able to accurately describe the state of biodiversity. Traditional surveys of vertebrate fauna involve time-consuming and skill-demanding field methods. Recently, the use of DNA derived from invertebrate parasites (leeches and blowflies) was suggested as a new tool for vertebrate diversity assessment. Bloodmeal analyses of arthropod disease vectors have long been performed to describe their feeding behaviour, for epidemiological purposes. On the other hand, this existing expertise has not yet been applied to investigate vertebrate fauna per se. Here, we evaluate the usefulness of hematophagous dipterans as vertebrate samplers. Blood-fed sand flies and mosquitoes were collected in Amazonian forest sites and analysed using high-throughput sequencing of short mitochondrial markers. Bloodmeal identifications highlighted contrasting ecological features and feeding behaviour among dipteran species, which allowed unveiling arboreal and terrestrial mammals of various body size, as well as birds, lizards and amphibians. Additionally, lower vertebrate diversity was found in sites undergoing higher levels of human-induced perturbation. These results suggest that, in addition to providing precious information on disease vector host use, dipteran bloodmeal analyses may represent a useful tool in the study of vertebrate communities. Although further effort is required to validate the approach and consider its application to large-scale studies, this first work opens up promising perspectives for biodiversity monitoring and eco-epidemiology. © 2017 John Wiley & Sons Ltd.

Carbon Nanotube Integrative Sampler (CNIS) for passive sampling of nanosilver in the aquatic environment.

Science.gov (United States)

Shen, Li; Fischer, Jillian; Martin, Jonathan; Hoque, Md Ehsanul; Telgmann, Lena; Hintelmann, Holger; Metcalfe, Chris D; Yargeau, Viviane

2016-11-01

Nanomaterials such as nanosilver (AgNP) can be released into the aquatic environment through production, usage, and disposal. Sensitive and cost-effective methods are needed to monitor AgNPs in the environment. This work is hampered by a lack of sensitive methods to detect nanomaterials in environmental matrixes. The present study focused on the development, calibration and application of a passive sampling technique for detecting AgNPs in aquatic matrixes. A Carbon Nanotube Integrative Sampler (CNIS) was developed using multi-walled carbon nanotubes (CNTs) as the sorbent for accumulating AgNPs and other Ag species from water. Sampling rates were determined in the laboratory for different sampler configurations and in different aquatic matrixes. The sampler was field tested at the Experimental Lakes Area, Canada, in lake water dosed with AgNPs. For a configuration of the CNIS consisting of CNTs bound to carbon fiber (i.e. CNT veil) placed in Chemcatcher® housing, the time weighted average (TWA) concentrations of silver estimated from deployments of the sampler in lake mesocosms dosed with AgNPs were similar to the measured concentrations of "colloidal silver" (i.e. <0.22μm in size) in the water column. For a configuration of CNIS consisting of CNTs in loose powder form placed in a custom made housing that were deployed in a whole lake dosed with AgNPs, the estimated TWA concentrations of "CNIS-labile Ag" were similar to the concentrations of total silver measured in the epilimnion of the lake. However, sampling rates for the CNIS in various matrixes are relatively low (i.e. 1-20mL/day), so deployment periods of several weeks are required to detect AgNPs at environmentally relevant concentrations, which can allow biofilms to develop on the sampler and could affect the sampling rates. With further development, this novel sampler may provide a simple and sensitive method for screening for the presence of AgNPs in surface waters. Copyright © 2016 Elsevier B.V. All

Fast monitoring of indoor bioaerosol concentrations with ATP bioluminescence assay using an electrostatic rod-type sampler.

Directory of Open Access Journals (Sweden)

Ji-Woon Park

Full Text Available A culture-based colony counting method is the most widely used analytical technique for monitoring bioaerosols in both indoor and outdoor environments. However, this method requires several days for colony formation. In this study, our goal was fast monitoring (Sampling: 3 min, Detection: < 1 min of indoor bioaerosol concentrations with ATP bioluminescence assay using a bioaerosol sampler. For this purpose, a novel hand-held electrostatic rod-type sampler (110 mm wide, 115 mm long, and 200 mm tall was developed and used with a commercial luminometer, which employs the Adenosine triphosphate (ATP bioluminescence method. The sampler consisted of a wire-rod type charger and a cylindrical collector, and was operated with an applied voltage of 4.5 kV and a sampling flow rate of 150.7 lpm. Its performance was tested using Staphylococcus epidermidis which was aerosolized with an atomizer. Bioaerosol concentrations were measured using ATP bioluminescence method with our sampler and compared with the culture-based method using Andersen cascade impactor under controlled laboratory conditions. Indoor bioaerosol concentrations were also measured using both methods in various indoor environments. A linear correlation was obtained between both methods in lab-tests and field-tests. Our proposed sampler with ATP bioluminescence method may be effective for fast monitoring of indoor bioaerosol concentrations.

Silicone passive equilibrium samplers as ‘chemometers’ in eels and sediments of a Swedish lake

DEFF Research Database (Denmark)

Jahnke, Annika; Mayer, Philipp; McLachlan, Michael S.

2014-01-01

Passive equilibrium samplers deployed in two or more media of a system and allowed to come to equilibrium can be viewed as ‘chemometers’ that reflect the difference in chemical activities of contaminants between the media. We applied silicone-based equilibrium samplers to measure relative chemica...... diagenesis and sorption to phytoplankton. The ‘chemometer’ approach has the potential to become a powerful tool to study the thermodynamic controls on persistent organic chemicals in the environment and should be extended to other environmental compartments.......Passive equilibrium samplers deployed in two or more media of a system and allowed to come to equilibrium can be viewed as ‘chemometers’ that reflect the difference in chemical activities of contaminants between the media. We applied silicone-based equilibrium samplers to measure relative chemical...... activities of seven ‘indicator’ polychlorinated biphenyls (PCBs) and hexachlorobenzene in eels and sediments from a Swedish lake. Chemical concentrations in eels and sediments were also measured using exhaustive extraction methods. Lipid-normalized concentrations in eels were higher than organic carbon...

Developments in Emission Measurements Using Lightweight Sensors and Samplers.

Science.gov (United States)

Lightweight emission measurement systems making use of miniaturized sensors and samplers have been developed for portable and aerial sampling for an array of pollutants. Shoebox-sized systems called “Kolibri”, weighing 3-5 kg, have been deployed on NASA-flown unmanned...

Upstream cash cloud

International Nuclear Information System (INIS)

Shepherd, R.

1998-01-01

This paper focuses on the effects of the slowdown in budgetary growth on the upstream business and offshore services. The dangers facing investors, the strong growth in energy demand, oil company priorities, the dip in profits of the oil companies, new field economics, the budgets for exploration and production, and the rig market outlook are discussed. (UK)

Comparison of particulate matter exposure estimates in young children from personal sampling equipment and a robotic sampler.

Science.gov (United States)

Sagona, Jessica A; Shalat, Stuart L; Wang, Zuocheng; Ramagopal, Maya; Black, Kathleen; Hernandez, Marta; Mainelis, Gediminas

2017-05-01

Accurate characterization of particulate matter (PM) exposure in young children is difficult, because personal samplers are often too heavy, bulky or impractical to be used. The Pretoddler Inhalable Particulate Environmental Robotic (PIPER) sampler was developed to help address this problem. In this study, we measured inhalable PM exposures in 2-year-olds via a lightweight personal sampler worn in a small backpack and evaluated the use of a robotic sampler with an identical sampling train for estimating PM exposure in this age group. PM mass concentrations measured by the personal sampler ranged from 100 to almost 1,200 μg/m 3 , with a median value of 331 μg/m 3 . PM concentrations measured by PIPER were considerably lower, ranging from 14 to 513 μg/m 3 with a median value of 56 μg/m 3 . Floor cleaning habits and activity patterns of the 2-year-olds varied widely by home; vigorous play and recent floor cleaning were most associated with higher personal exposure. Our findings highlight the need for additional characterization of children's activity patterns and their effect on personal exposures.

Assessment of personal exposure to airborne nanomaterials: Evaluation of a novel sampler

International Nuclear Information System (INIS)

Faure, Bertrand; Dozol, Hélène; Brouard, Christophe; Guiot, Arnaud; Clavaguera, Simon

2017-01-01

A novel sampler, the NANOBADGE, has been developed to assess personal exposure to nano-objects, agglomerates and aggregates (NOAA) at the workplace. The NANOBADGE collects particles on filters subsequently analyzed by X-Ray Fluorescence spectroscopy (XRF), which provides a mass-based quantification with chemical selectivity. The NANOBADGE was benchmarked against a scanning mobility particle sizer (SMPS) and a DiSCmini by carrying out simultaneous measurements on test aerosols of ZnO or TiO 2 for particle sizes between 20 and 400 nm for which the DiSCmini has its highest accuracy. The effective density and shape of the NOAA present in the test aerosols were determined experimentally to compare number-based data obtained with the SMPS and the DiSCmini with mass-based data obtained with the NANOBADGE. The agreement between the SMPS and the NANOBADGE sampler was within ± 25 % on all test aerosols. The converted DiSCmini data matched the SMPS and sampler data for polydisperse aerosols in the specified size range as long as the DiSCmini assumptions meet the aerosol characteristics (i.e. lognormal size distribution with a given geometric standard deviation σg = 1.9). The detection limits of the NANOBADGE sampler were in the order of tens of nanograms per filter, which is low enough to reliably detect exposure levels below the recommended exposure limit (REL) of the National Institute for Occupational Safety and Health (NIOSH) and the Institut National de Recherche et de Sécurité (INRS) for ultrafine ZnO and TiO 2 even for short-term exposure situations. (paper)

Effect of housing geometry on the performance of ChemcatcherTM passive sampler for the monitoring of hydrophobic organic pollutants in water

International Nuclear Information System (INIS)

Lobpreis, Tomas; Vrana, Branislav; Dominiak, Ewa; Dercova, Katarina; Mills, Graham A.; Greenwood, Richard

2008-01-01

Passive sampling of pollutants in water has been gaining acceptance for environmental monitoring. Previously, an integrative passive sampler (the Chemcatcher TM ) was developed and calibrated for the measurement of time weighted average concentrations of hydrophobic pollutants in water. Effects of physicochemical properties and environmental variables (water temperature and turbulence) on kinetic and thermodynamic parameters characterising the exchange of analytes between the sampler and water have been published. In this study, the effect of modification in sampler housing geometry on these calibration parameters was studied. The results obtained for polycyclic aromatic hydrocarbons show that reducing the depth of the cavity in the sampler body geometry increased the exchange kinetics by approximately twofold, whilst having no effect on the correlation between the uptake and offload kinetics of analytes. The use of performance reference compounds thus avoids the need for extensive re-calibration when the sampler body geometry is modified. - The effect of passive sampler geometry on accumulation kinetics of organic pollutants from water was evaluated

A numerical study on the flow upstream of a wind turbine on complex terran

DEFF Research Database (Denmark)

Meyer Forsting, Alexander Raul; Bechmann, Andreas; Troldborg, Niels

2016-01-01

The interaction of a wind turbine with the upstream flow-field in complex and flat terrain is studied using Reynolds-averaged Navier-Stokes (RANS) simulations with a two equation turbulence closure. The complex site modelled is Perdigao (Portugal), where a turbine is located on one of two parallel...... the wind turbine wake trajectory which in turn governs the orientation of the induction zone...

Waveform Sampler CAMAC Module

International Nuclear Information System (INIS)

Freytag, D.R.; Haller, G.M.; Kang, H.; Wang, J.

1985-09-01

A Waveform Sampler Module (WSM) for the measurement of signal shapes coming from the multi-hit drift chambers of the SLAC SLC detector is described. The module uses a high speed, high resolution analog storage device (AMU) developed in collaboration between SLAC and Stanford University. The AMU devices together with high speed TTL clocking circuitry are packaged in a hybrid which is also suitable for mounting on the detector. The module is in CAMAC format and provides eight signal channels, each recording signal amplitude versus time in 512 cells at a sampling rate of up to 360 MHz. Data are digitized by a 12-bit ADC with a 1 μs conversion time and stored in an on-board memory accessible through CAMAC

Radon gas sampler for indoor and soil measurements and its applications

International Nuclear Information System (INIS)

Azimi-Garakani, D.; Flores, B.; Piermattei, S.; Susanna, A.F.; Seidel, J.L.; Tommasino, L.; Torri, G.

1988-01-01

A national large scale survey of indoor radon (based on an optimised sampling strategy) is needed in Italy to obtain average population dose for use in epidemiological studies. Since in the great majority of cases, one of the most important radon sources is the soil and rock beneath the houses, it would be interesting to combine this survey with measurements of bed-soil radon. With these objectives in mind, a new radon monitor device has been developed consisting of two etched track detectors enclosed in a heat-sealed polyethylene bag. When compared with existing techniques, this radon gas sampler presents several advantages for both indoor and outdoor measurements. As a pilot project, radon gas measurements have been carried out in hundreds of different sites and for several locations; measurements have been made for different years. Typical houses with relatively high radon concentrations have also been thoroughly investigated. (author)

Design and laboratory testing of a new flow-through directional passive air sampler for ambient particulate matter.

Science.gov (United States)

Lin, Chun; Solera Garcia, Maria Angeles; Timmis, Roger; Jones, Kevin C

2011-03-01

A new type of directional passive air sampler (DPAS) is described for collecting particulate matter (PM) in ambient air. The prototype sampler has a non-rotating circular sampling tray that is divided into covered angular channels, whose ends are open to winds from sectors covering the surrounding 360°. Wind-blown PM from different directions enters relevant wind-facing channels, and is retained there in collecting pools containing various sampling media. Information on source direction and type can be obtained by examining the distribution of PM between channels. Wind tunnel tests show that external wind velocities are at least halved over an extended area of the collecting pools, encouraging PM to settle from the air stream. Internal and external wind velocities are well-correlated over an external velocity range of 2.0-10.0 m s⁻¹, which suggests it may be possible to relate collected amounts of PM simply to ambient concentrations and wind velocities. Measurements of internal wind velocities in different channels show that velocities decrease from the upwind channel round to the downwind channel, so that the sampler effectively resolves wind directions. Computational fluid dynamics (CFD) analyses were performed on a computer-generated model of the sampler for a range of external wind velocities; the results of these analyses were consistent with those from the wind tunnel. Further wind tunnel tests were undertaken using different artificial particulates in order to assess the collection performance of the sampler in practice. These tests confirmed that the sampler can resolve the directions of sources, by collecting particulates preferentially in source-facing channels.

Characteristics and Sampling Efficiencies of Two Impactor Bioaerosol Samplers: MAS-100(Registered) (Microbial Air Monitoring System) and Single-Stage Andersen Viable Microbial Samplers

National Research Council Canada - National Science Library

Hottell, K

2004-01-01

.... A petri dish with agar is used as the impaction surface for these samplers. The MAS-l00 is a single-stage impactor that aspirates air through a 400-hole perforated entry plate onto an agar plate at an airflow rate of 100 L/min...

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

International Nuclear Information System (INIS)

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

1980-01-01

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

Accuracy criteria recommended for the certification of gravimetric coal-mine-dust samplers

International Nuclear Information System (INIS)

Bowman, J.D.; Bartley, D.L.; Breuer, G.M.; Doemeny, L.J.; Murdock, D.J.

1984-07-01

Procedures for testing bias and precision of gravimetric coal-mine-dust sampling units are reviewed. Performance criteria for NIOSH certification of personal coal-mine dust samplers are considered. The NIOSH criterion is an accuracy of 25% at the 95% confidence interval. Size distributions of coal-mine-dust are discussed. Methods for determining size distributions are described. Sampling and sizing methods are considered. Cyclone parameter estimation is discussed. Bias computations for general sampling units are noted. Recommended procedures for evaluating bias and precision of gravimetric coal mine dust personal samplers are given. The authors conclude that when cyclones are operated at lower rates, the NIOSH accuracy criteria can be met

Upstream Atlantic salmon (Salmo salar) passage

International Nuclear Information System (INIS)

Clay, C.H.

1993-01-01

Upstream salmon passage though a dam is discussed with respect to three main components: the fishway entrance, the fishway, and the exit. Design considerations and alternative types of components are presented. For fishway entrances, an important consideration is the positioning of the entrance as far upstream as the fish can swim with respect to obstacles. For powerhouses using water diverted from a river, the problem of leading fish past the powerhouse may be overcome by either installing a tailrace barrier or increasing the flow until the home stream odor is sufficient to attract fish. Swimming ability should be the first consideration in fishway design. Fishways with 50 cm drops per pool would be satisfactory in most cases. The problem of headwater fluctuation is overcome through careful fishway selection. Fish locks, hoists, and elevators are other alternatives to pool/weir fishways. The location for a fish exit must be decided on the basis of whether the fishway will be used only for upstream migrations. 5 refs., 1 fig., 1 tab

7 CFR 61.33 - Equipment of sampler; contents of certificate.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Equipment of sampler; contents of certificate. 61.33 Section 61.33 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS...

The effect of size-selective samplers (cyclones) on XRD response

CSIR Research Space (South Africa)

Pretorius, CJ

2011-07-01

Full Text Available The study evaluated five size-selective samplers used in the South African mining industry to determine how their performance affects the X-ray powder diffraction (XRD) response when respirable dust samples are analysed for quartz using direct...

Development of a silicone-membrane passive sampler for monitoring cylindrospermopsin and microcystin LR-YR-RR in natural waters

Science.gov (United States)

Nyoni, Hlengilizwe; Mamba, Bhekie B.; Msagati, Titus A. M.

2017-08-01

Silicone membrane tubes were functionalised by filling them with synthesised γ-Fe2O3 nanoparticles and used as a passive sampling device for monitoring microcystins and cylindrospermopsin in aquatic environments. This novel device was calibrated for the measurement of microcystin and cylindrospermopsin concentrations in water. The effect of temperature and hydrodynamics on the sampler performance was studied in a flow-through system under controlled conditions. The chemical uptake of microcystins (MCs) and cylindrospermopsin (CYN) into the passive sampler remained linear and integrative throughout the exposure period. The rate of accumulation of most of the MC compounds tested was dependent on temperature and flow velocity. The use of 13C labelled polychlorinated biphenyls as performance reference compounds (PRCs) in silicone membrane/γ-Fe2O3 nanoparticle passive sampler, Chemcatcher and polar organic chemical integrative sampler (POCIS) was evaluated. The majority of PRCs improved the semi quantitative nature of water concentration estimated by the three samplers. The corrected sampling rate values of model biotoxin compounds were used to estimate the time-weighted average concentrations in natural cyanobacterial water blooms of the Hartbeespoort dam. The corrected sampling rates RScorr values varied from 0.1140 to 0.5628 Ld-1 between samplers with silicone membrane having the least RScorr values compared to the Chemcatcher and POCIS. The three passive sampling devises provided a more relevant picture of the biotoxin concentration in the Hartbeespoort dam. The results suggested that the three sampling devices are suitable for use in monitoring microcystins and cylindrospermopsin concentrations in aquatic environments.

Different papillomaviruses have different repertoires of transcription factor binding sites: convergence and divergence in the upstream regulatory region

Directory of Open Access Journals (Sweden)

Alonso Ángel

2006-03-01

Full Text Available Abstract Background Papillomaviruses (PVs infect stratified squamous epithelia in warm-blooded vertebrates and have undergone a complex evolutionary process. The control of the expression of the early ORFs in PVs depends on the binding of cellular and viral transcription factors to the upstream regulatory region (URR of the virus. It is believed that there is a core of transcription factor binding sites (TFBS common to all PVs, with additional individual differences, although most of the available information focuses only on a handful of viruses. Results We have studied the URR of sixty-one PVs, covering twenty different hosts. We have predicted the TFBS present in the URR and analysed these results by principal component analysis and genetic algorithms. The number and nature of TFBS in the URR might be much broader than thus far described, and different PVs have different repertoires of TFBS. Conclusion There are common fingerprints in the URR in PVs that infect primates, although the ancestors of these viruses diverged a long time ago. Additionally, there are obvious differences between the URR of alpha and beta PVs, despite these PVs infect similar histological cell types in the same host, i.e. human. A thorough analysis of the TFBS in the URR might provide crucial information about the differential biology of cancer-associated PVs.

Evaluation of the performance of a passive sampler in the monitoring of benzene and other volatile aromatic compounds in urban and indoor sites

International Nuclear Information System (INIS)

Bertoni, G.; Tappa, R.; Allegrini, I.

1999-01-01

Laboratory and field tests have been performed on a new passive device, properly designed for the collection of volatile organic compounds from ambient air on an active charcoal layer. Tests performed in order to determine accuracy and precision, response linearity and employment limits show that this device may be helpful in long and medium-time determinations of BTX (benzene, toluene and xylenes) in the atmosphere. The sampler is optimised for a four weeks sampling in open air [it

A critical assessment of passive air samplers for per- and polyfluoroalkyl substances

Science.gov (United States)

Karásková, Pavlína; Codling, Garry; Melymuk, Lisa; Klánová, Jana

2018-07-01

Since their inclusion in the Stockholm Convention, there has been a need for global monitoring of perfluorooctane sulfonate (PFOS), its salts and perfluorooctanesulfonyl fluoride (PFOSF), along with other non-listed highly fluorinated compounds. Passive air samplers (PAS) are ideal for geographic coverage of atmospheric monitoring. The most common type of PAS, using polyurethane foam (PUF) as a sorbent, was primarily developed for non-polar semivolatile organic compounds (SVOCs) and are not well-validated for polar substances such as the per- and polyfluoroalkyl substances (PFASs), however, they have been used for some PFASs, particularly PFOS. To evaluate their applicability, PAS were deployed for measurement of PFASs in outdoor and indoor air. Outdoors, two types of PAS, one consisting of PUF and one of XAD-2 resin, were deployed in an 18-week calibration study in parallel with a low-volume active air sampler (LV-AAS) in a suburban area. Indoors, PUF-PAS were similarly deployed over 12 weeks to evaluate their applicability for indoor monitoring. Samples were analysed for perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkyl sulfonates (PFSAs), perfluorooctane sulfonamides (FOSAs), and perfluorooctane sulfonamidoethanols (FOSEs). In outdoor air, 17 out of the 21 PFAS were detected in more than 50% of samples, with a median ∑17PFASs of 18.0 pg m-3 while 20 compounds were detected in indoor air with a median concentration ∑20PFASs of 76.6 pg m-3 using AAS samplers. PFOS was the most common PFAS in the outdoor air while PFBA was most common indoors. Variability between PAS and AAS was observed and comparing gas phase and particle phase separately or in combination did not account for the variation observed. PUF-PAS may still have a valuable use in PFAS monitoring but more work is needed to identify the applicability of passive samplers for ionic PFAS.

Upstream health law.

Science.gov (United States)

Sage, William M; McIlhattan, Kelley

2014-01-01

For the first time, entrepreneurs are aggressively developing new technologies and business models designed to improve individual and population health, not just to deliver specialized medical care. Consumers of these goods and services are not yet "patients"; they are simply people. As this sector of the health care industry expands, it is likely to require new forms of legal governance, which we term "upstream health law." © 2014 American Society of Law, Medicine & Ethics, Inc.

Airborne radioiodine species sampler and it's application for measuring removal efficiencies of large charcoal adsorbers for ventilation exhaust air

International Nuclear Information System (INIS)

Emel, D.; Hetzer, D.; Pelletier, C.A.; Barefoot, E.D.; Cline, J.E.

1976-01-01

A program, sponsored by the Electric Power Research Institute, is underway to determine the chemical species of radioiodine coming from LWR power plants and their persistence in the nearby environment. In support of this program, an airborne radioiodine sampler, developed and used by the AEC was modified and tested. This sampler consists of five components. The components are: (1) a particulate filter, (2) CdI 2 on a matrix of chromosorb-P to retain I 2 , (3) 4-Iodophenol on a matrix of activated alumina to retain HOI, (4) silver exchanged molecular sieve-13X to retain organic iodides, and (5) impregnated charcoal to serve as a control. The AEC sampler has not been proof-tested for periods over 48 hours or for flow rates above 0.10 l/s. For maximum sensitivity, a sampler is required to be used for periods of one to two weeks and at a flow rate giving a bed residence time of 0.1 sec. The AEC sampler was scaled up in size to attain an air sampling rate of 0.9 l/s. Each media for this sampler (except the particulate filter) was tested in the laboratory for retention of the iodine species; I 2 , Organic, and HOI. The tests were conducted at typical conditions observed at the main iodine release points at nuclear power plants. Confirmatory tests were run at operating nuclear power plants. The test results showed that under normal plant conditions the sampler could be operated at flow rates up to 0.80 l/s and differentiate the iodine species I 2 , HOI, and CH 3 I. The retention efficiencies of each media for its specie of radioiodine were found to be: I 2 on CdI 2 - 87 +- 5%, HOI on IPH 94 +- 4%, and CH 3 I on Ag 13-X or KI charcoal 99 +- 1%

Composite sampling of a Bacillus anthracis surrogate with cellulose sponge surface samplers from a nonporous surface.

Directory of Open Access Journals (Sweden)

Jenia A M Tufts

Full Text Available A series of experiments was conducted to explore the utility of composite-based collection of surface samples for the detection of a Bacillus anthracis surrogate using cellulose sponge samplers on a nonporous stainless steel surface. Two composite-based collection approaches were evaluated over a surface area of 3716 cm2 (four separate 929 cm2 areas, larger than the 645 cm2 prescribed by the standard Centers for Disease Control (CDC and Prevention cellulose sponge sampling protocol for use on nonporous surfaces. The CDC method was also compared to a modified protocol where only one surface of the sponge sampler was used for each of the four areas composited. Differences in collection efficiency compared to positive controls and the potential for contaminant transfer for each protocol were assessed. The impact of the loss of wetting buffer from the sponge sampler onto additional surface areas sampled was evaluated. Statistical tests of the results using ANOVA indicate that the collection of composite samples using the modified sampling protocol is comparable to the collection of composite samples using the standard CDC protocol (p  =  0.261. Most of the surface-bound spores are collected on the first sampling pass, suggesting that multiple passes with the sponge sampler over the same surface may be unnecessary. The effect of moisture loss from the sponge sampler on collection efficiency was not significant (p  =  0.720 for both methods. Contaminant transfer occurs with both sampling protocols, but the magnitude of transfer is significantly greater when using the standard protocol than when the modified protocol is used (p<0.001. The results of this study suggest that composite surface sampling, by either method presented here, could successfully be used to increase the surface area sampled per sponge sampler, resulting in reduced sampling times in the field and decreased laboratory processing cost and turn-around times.

A survey of perfluoroalkyl sulfonamides in indoor and outdoor air using passive air samplers

Energy Technology Data Exchange (ETDEWEB)

Shoeib, M.; Harner, T. [Meteorological Service of Canada, Environment Canada (Canada); Wilford, B.; Jones, K. [Lancaster Univ. (United Kingdom). Environmental Science; Zhu, J. [Chemistry Research Division, Health Canada, Tunney' s Pasture, Ottawa (Canada)

2004-09-15

Perfluorooctane sulfonate (PFOS) has recently emerged as a priority environmental pollutant due to its widespread detection in biological samples from remote regions including the Arctic and the Mid-North Pacific Ocean. Because PFOS is fairly involatile, it is hypothesized that its occurrence in remote regions is the result of atmospheric transport of more volatile precursor compounds such as the perfluoroalkyl sulfonamides (PFASs). PFASs are used in variety of consumer products for water and oil resistance including surface treatments for fabric, upholstery, carpet, paper and leather. In a recent pilot study employing high volume air samples, indoor air concentrations of PFASs were approximately 100 times greater than outdoor levels. This is of significance because people typically spend about 90% of their time indoors 5 and this exposure may serve as an important uptake pathway. Indoor air also serves as a source of PFASs to the outside where PFASs are ultimately transported and distributed throughout the environment. The current study is intended to be a more comprehensive survey of indoor and outdoor air allowing more confident conclusions to be made. Passive air samplers comprised of polyurethane foam (PUF) disks were used. These are quiet, non-intrusive samplers that operate without the aid of a pump or electricity. Air movement delivers chemical to the sampler which has a high retention capacity for persistent organic pollutants (POPs). PUF disks samplers have been previously used successfully to monitor different classes of hydrophobic persistent organic pollutants POPs.

7 CFR 801.5 - Tolerance for diverter-type mechanical samplers.

Science.gov (United States)

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Tolerance for diverter-type mechanical samplers. 801.5 Section 801.5 Agriculture Regulations of the Department of Agriculture (Continued) GRAIN INSPECTION... OFFICIAL PERFORMANCE REQUIREMENTS FOR GRAIN INSPECTION EQUIPMENT § 801.5 Tolerance for diverter-type...

Energetic particle diffusion coefficients upstream of quasi-parallel interplanetary shocks

Science.gov (United States)

Tan, L. C.; Mason, G. M.; Gloeckler, G.; Ipavich, F. M.

1989-01-01

The properties of about 30 to 130-keV/e protons and alpha particles upstream of six quasi-parallel interplanetary shocks that passed by the ISEE 3 spacecraft during 1978-1979 were analyzed, and the values for the upstream energegic particle diffusion coefficient, kappa, in these six events were deduced for a number of energies and upstream positions. These observations were compared with predictions of Lee's (1983) theory of shock acceleration. It was found that the observations verified the prediction of the A/Q dependence (where A and Q are the particle atomic mass and ionization state, respectively) of kappa for alpha and proton particles upstream of the quasi-parallel shocks.

Evaluation of intake efficiencies and associated sediment-concentration errors in US D-77 bag-type and US D-96-type depth-integrating suspended-sediment samplers

Science.gov (United States)

Sabol, Thomas A.; Topping, David J.

2013-01-01

Accurate measurements of suspended-sediment concentration require suspended-sediment samplers to operate isokinetically, within an intake-efficiency range of 1.0 ± 0.10, where intake efficiency is defined as the ratio of the velocity of the water through the sampler intake to the local ambient stream velocity. Local ambient stream velocity is defined as the velocity of the water in the river at the location of the nozzle, unaffected by the presence of the sampler. Results from Federal Interagency Sedimentation Project (FISP) laboratory experiments published in the early 1940s show that when the intake efficiency is less than 1.0, suspended-sediment samplers tend to oversample sediment relative to water, leading to potentially large positive biases in suspended-sediment concentration that are positively correlated with grain size. Conversely, these experiments show that, when the intake efficiency is greater than 1.0, suspended‑sediment samplers tend to undersample sediment relative to water, leading to smaller negative biases in suspended-sediment concentration that become slightly more negative as grain size increases. The majority of FISP sampler development and testing since the early 1990s has been conducted under highly uniform flow conditions via flume and slack-water tow tests, with relatively little work conducted under the greater levels of turbulence that exist in actual rivers. Additionally, all of this recent work has been focused on the hydraulic characteristics and intake efficiencies of these samplers, with no field investigations conducted on the accuracy of the suspended-sediment data collected with these samplers. When depth-integrating suspended-sediment samplers are deployed under the more nonuniform and turbulent conditions that exist in rivers, multiple factors may contribute to departures from isokinetic sampling, thus introducing errors into the suspended-sediment data collected by these samplers that may not be predictable on the basis

CAM and stack air sampler design guide

International Nuclear Information System (INIS)

Phillips, T.D.

1994-01-01

About 128 air samplers and CAMs presently in service to detect and document potential radioactive release from 'H' and 'F' area tank farm ventilation stacks are scheduled for replacement and/or upgrade by Projects S-5764, S-2081, S-3603, and S-4516. The seven CAMs scheduled to be upgraded by Project S-4516 during 1995 are expected to provide valuable experience for the three remaining projects. The attached document provides design guidance for the standardized High Level Waste air sampling system

Task QA plan for Modified Prototypic Hydragard trademark Sampler Overflow System Demonstration at TNX

International Nuclear Information System (INIS)

Snyder, T.K.

1993-01-01

The primary objective of this task is to evaluate the proposed design modifications to the sample system, including the adequacy of the recommended eductor and the quality of samples obtained from the modified system. Presently, the sample streams are circulated from the originating tank, through a Hydragard trademark sampler system, and back to the originating tank. The overflow from the Hydragard trademark sampler flows to the Recycle Collection Tank (RCT). This report outlines the planned quality assurance controls for the design modification task, including organization and personnel, surveillances, and records package

The occurrence of illicit and therapeutic pharmaceuticals in wastewater effluent and surface waters in Nebraska

Energy Technology Data Exchange (ETDEWEB)

Bartelt-Hunt, Shannon L. [Department of Civil Engineering, University of Nebraska-Lincoln, 203B Peter Kiewit Institute, Omaha, NE 68182-0178 (United States)], E-mail: sbartelt2@unl.edu; Snow, Daniel D.; Damon, Teyona [Water Sciences Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68583-0844 (United States); Shockley, Johnette [Department of Civil Engineering, University of Nebraska-Lincoln, 203B Peter Kiewit Institute, Omaha, NE 68182-0178 (United States); Hoagland, Kyle [UNL Water Center, University of Nebraska-Lincoln, Lincoln, NE 68583-0995 (United States)

2009-03-15

The occurrence and estimated concentration of twenty illicit and therapeutic pharmaceuticals and metabolites in surface waters influenced by wastewater treatment plant (WWTP) discharge and in wastewater effluents in Nebraska were determined using Polar Organic Chemical Integrative Samplers (POCIS). Samplers were installed in rivers upstream and downstream of treated WWTP discharge at four sites and in a discharge canal at a fifth location. Based on differences in estimated concentrations determined from pharmaceuticals recovered from POCIS, WWTP effluent was found to be a significant source of pharmaceutical loading to the receiving waters. Effluents from WWTPs with trickling filters or trickling filters in parallel with activated sludge resulted in the highest observed in-stream pharmaceutical concentrations. Azithromycin, caffeine, 1,7-dimethylzanthine, carbamazepine, cotinine, DEET, diphenhydramine, and sulfamethazine were detected at all locations. Methamphetamine, an illicit pharmaceutical, was detected at all but one of the sampling locations, representing only the second report of methamphetamine detected in WWTP effluent and in streams impacted by WWTP effluent. - Passive samplers were used to develop semi-quantitative estimates of pharmaceutical concentrations in receiving waters influenced by wastewater effluent.

The occurrence of illicit and therapeutic pharmaceuticals in wastewater effluent and surface waters in Nebraska

International Nuclear Information System (INIS)

Bartelt-Hunt, Shannon L.; Snow, Daniel D.; Damon, Teyona; Shockley, Johnette; Hoagland, Kyle

2009-01-01

The occurrence and estimated concentration of twenty illicit and therapeutic pharmaceuticals and metabolites in surface waters influenced by wastewater treatment plant (WWTP) discharge and in wastewater effluents in Nebraska were determined using Polar Organic Chemical Integrative Samplers (POCIS). Samplers were installed in rivers upstream and downstream of treated WWTP discharge at four sites and in a discharge canal at a fifth location. Based on differences in estimated concentrations determined from pharmaceuticals recovered from POCIS, WWTP effluent was found to be a significant source of pharmaceutical loading to the receiving waters. Effluents from WWTPs with trickling filters or trickling filters in parallel with activated sludge resulted in the highest observed in-stream pharmaceutical concentrations. Azithromycin, caffeine, 1,7-dimethylzanthine, carbamazepine, cotinine, DEET, diphenhydramine, and sulfamethazine were detected at all locations. Methamphetamine, an illicit pharmaceutical, was detected at all but one of the sampling locations, representing only the second report of methamphetamine detected in WWTP effluent and in streams impacted by WWTP effluent. - Passive samplers were used to develop semi-quantitative estimates of pharmaceutical concentrations in receiving waters influenced by wastewater effluent

Evaluation of Intake Efficiencies and Associated Sediment-Concentration Errors in US D-77 Bag-Type and US D-96-Type Depth-Integrating Suspended-Sediment Samplers

Science.gov (United States)

Sabol, T. A.; Topping, D. J.; Griffiths, R. E.

2011-12-01

Accurate measurements of suspended-sediment concentration require suspended-sediment samplers to operate isokinetically with an intake-efficiency of 1.0 ± 0.10. Results from 1940s Federal Interagency Sedimentation Project (FISP) laboratory experiments show that when the intake efficiency does not equal 1.0, suspended-sediment samplers either under- or oversample sediment relative to water, leading to biases in suspended-sediment concentration. The majority of recent FISP sampler development and testing has been conducted under uniform flow conditions using flume and slack-water tow tests, with little testing in actual turbulent rivers. Recent work has focused on the hydraulic characteristics and intake efficiencies of these samplers, without field investigations of the accuracy of the suspended-sediment data collected with these samplers. When depth-integrating suspended-sediment samplers are deployed under the non-uniform and turbulent conditions that exist in rivers, multiple factors may contribute to departures from isokinetic sampling. This introduces errors into the suspended-sediment data that may not be predictable on the basis of flume and tow tests alone. This study (1) evaluates the intake efficiencies of the older US D-77 bag-type and newer, FISP-approved US D-96 samplers at multiple river cross sections under a range of flow conditions; (2) examines if water temperature and sampling duration explain measured differences in intake efficiency between samplers and between laboratory and field tests; (3) models and predicts the directions and magnitudes of errors in measured suspended-sand concentration; and (4) determines if the relative differences in suspended-sediment concentration in a variety of size classes are consistent with the differences expected on the basis of the 1940s FISP-laboratory experiments. Results indicate that under river conditions, the intake efficiency of the US D-96 sampler is superior to that of the US D-77 bag-type sampler and

Evaluation of personal inhalable aerosol samplers with different filters for use during anthrax responses.

Science.gov (United States)

Grinshpun, Sergey A; Weber, Angela M; Yermakov, Michael; Indugula, Reshmi; Elmashae, Yousef; Reponen, Tiina; Rose, Laura

2017-08-01

Risk of inhalation exposure to viable Bacillus anthracis (B. anthracis) spores has primarily been assessed using short-term, stationary sampling methods which may not accurately characterize the concentration of inhalable-sized spores reaching a person's breathing zone. While a variety of aerosol sampling methods have been utilized during previous anthrax responses, no consensus has yet been established for personal air sampling. The goal of this study was to determine the best sampler-filter combination(s) for the collection and extraction of B. anthracis spores. The study was designed to (1) evaluate the performance of four filter types (one mixed cellulose ester, MCE (pore size = 3 µm), two polytetrafluoroethylene, PTFE (1 and 3 µm), and one polycarbonate, PC (3 µm)); and (2) evaluate the best performing filters in two commercially available inhalable aerosol samplers (IOM and Button). Bacillus thuringiensis kurstaki [Bt(k)], a simulant for B. anthracis, served as the aerosol challenge. The filters were assessed based on criteria such as ability to maintain low pressure drop over an extended sampling period, filter integrity under various environmental conditions, spore collection and extraction efficiencies, ease of loading and unloading the filters into the samplers, cost, and availability. Three of the four tested collection filters-except MCE-were found suitable for efficient collection and recovery of Bt(k) spores sampled from dry and humid as well as dusty and clean air environments for up to 8 hr. The PC (3 µm) filter was identified as the best performing filter in this study. The PTFE (3 µm) demonstrated a comparable performance, but it is more expensive. Slightly higher concentrations were measured with the IOM inhalable sampler which is the preferred sampler's performance criterion when detecting a highly pathogenic agent with no established "safe" inhalation exposure level. Additional studies are needed to address the effects of

The Winfrith portable self-contained air samplers, type W.A.S. 1

International Nuclear Information System (INIS)

Cavell, I.W.

1961-11-01

This memorandum describes a self-contained air sampler for collecting samples of airborne particulates on a standard 6 centimetre filter paper. Its construction, use and performance are discussed. (author)

A new application of passive samplers as indicators of in-situ biodegradation processes.

Science.gov (United States)

Belles, Angel; Alary, Claire; Criquet, Justine; Billon, Gabriel

2016-12-01

In this paper, a method for evaluating the in-situ degradation of nitro polycyclic aromatic hydrocarbons (nitro-PAH) in sediments is presented. The methodology is adapted from the passive sampler technique, which commonly uses the dissipation rate of labeled compounds loaded in passive sampler devices to sense the environmental conditions of exposure. In the present study, polymeric passive samplers (made of polyethylene strips) loaded with a set of labeled polycyclic aromatic hydrocarbons (PAH) and nitro-PAH were immersed in sediments (in field and laboratory conditions) to track the degradation processes. This approach is theoretically based on the fact that a degradation process induces a steeper concentration gradient of the labeled compounds in the surrounding sediment, thereby increasing their compound dissipation rates compared with their dissipation in abiotic conditions. Postulating that the degradation magnitude is the same for the labeled compounds loaded in polyethylene strips and for their native homologs that are potentially present in the sediment, the field degradation of 3 nitro-PAH (2-nitro-fluorene, 1-nitro-pyrene, 6-nitro-chrysene) was semi-quantitatively analyzed using the developed method. Copyright © 2016 Elsevier Ltd. All rights reserved.

Validation of ammonia diffusive and active samplers in a controlled atmosphere test facility using traceable Primary Standard Gas Mixtures

Science.gov (United States)

Martin, Nicholas A.; Ferracci, Valerio; Cassidy, Nathan; Hook, Josh; Battersby, Ross M.; Tang, Yuk S.; Stevens, Amy C. M.; Jones, Matthew R.; Braban, Christine F.; Gates, Linda; Hangartner, Markus; Stoll, Jean-Marc; Sacco, Paolo; Pagani, Diego; Hoffnagle, John A.

2017-04-01

Intensive animal farming, the increased use of fertilizers, and certain industrial processes are believed to be responsible for the observed increases in the amount fraction of ammonia (NH3) found in Europe. NH3 contributes to eutrophication and acidification of land and freshwater, potentially leading to a loss of biodiversity and undesirable changes to the ecosystem. It also contributes to the formation of secondary particulate matter (PM) formation, which is associated with poor air quality and adverse health outcomes. Measurements of ambient ammonia are principally carried out with low-cost diffusive samplers or by active sampling with denuders, with each method delivering time-integrated values over the monitoring period. However, such techniques have not yet been extensively validated. The goal of this work was to provide improvements in the metrological traceability through the determination of NH3 diffusive sampling rates. Five different designs of commercial diffusive samplers (FSM Radiello radial sampler, Gradko diffusion tube, Gradko DIFRAM-400, Passam ammonia sampler, and CEH ALPHA sampler) were employed, together with a pumped denuder sampler (CEH DELTA denuder) for comparison. All devices were simultaneously exposed for either 28 days or 14 days (dependent on sampler type) in a controlled atmosphere test facility (CATFAC) containing traceable amount fractions of humidified ammonia using new stable ammonia Primary Standard Gas Mixtures developed by gravimetry at NPL, under a wide range of conditions that are relevant to ambient monitoring. Online continuous monitoring of the ammonia test atmospheres was carried out by extractive sampling, employing a calibrated cavity ring-down spectrometer, which had been modified to account for cross interference by water vapour. Each manufacturer extracted the captured ammonia on the exposed samplers in the form of ammonium (NH4+) using their own accredited traceable wet chemical techniques, and then reported data

Visual Chronicles from the Balkans and Central Europe: Samplers Remembered

Directory of Open Access Journals (Sweden)

Maria-Alina Asavei

2016-03-01

Full Text Available This paper examines the relationship between craft and popular culture by focusing on a peculiar type of textile sampler (needlework that used to be omnipresent in the last century both in rural and urban houses across Central and South-Eastern Europe. Although these hand-crafted items are no longer part of today’s ‘compulsory’ household, they are still regarded as nostalgic, familiar or emotional forms of materiality and tangibility which perform a cultural politics of identity. These vernacular textiles predate the digital age and the free market and yet co-evolve and interact with digital networks and technologies. This paper brings into focus ‘amateur’ and regional forms of home grown cultural expression and the ways in which these forms of folk creativity and materiality are recast in contemporary urban popular culture and arts. Thus, the main aim of this study is to explore the contemporary re-enactments of these vernacular samplers.

Human Resource Local Content in Ghana's Upstream Petroleum Industry

Science.gov (United States)

Benin, Papa

Enactment of Ghana's Petroleum (Local Content and Local Participation) Regulations, 2013 (L.I. 2204) was intended to regulate the percentage of local products, personnel, financing, and goods and services rendered within Ghana's upstream petroleum industry value chain. Five years after the inception of Ghana's upstream oil and gas industry, a gap is evident between the requirements of L.I. 2204 and professional practice. Drawing on Lewin's change theory, a cross-sectional study was conducted to examine the extent of differences between the prevailing human resource local content and the requirements of L.I. 2204 in Ghana's upstream petroleum industry. The extent to which training acquired by indigenous Ghanaians seeking jobs in Ghana's oil fields affects the prevalent local content in its upstream petroleum industry was also examined. Survey data were collected from 97 management, technical, and other staff in 2 multinational petroleum companies whose oil and gas development plans have been approved by the Petroleum Commission of Ghana. To answer the research questions and test their hypotheses, one-way ANOVA was performed with staff category (management, technical, and other) as the independent variable and prevalent local content as the dependent variable. Results indicated that prevailing local content in Ghana's upstream petroleum industry meets the requirements of L.I. 2204. Further, training acquired by indigenous Ghanaians seeking jobs in Ghana's oil fields affects the prevalent local content in its offshore petroleum industry. Findings may encourage leaders within multinational oil companies and the Petroleum Commission of Ghana to organize educational seminars that equip indigenous Ghanaians with specialized skills for working in Ghana's upstream petroleum industry.

Development of an automatic smear sampler and evaluation of surface contamination

International Nuclear Information System (INIS)

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

2004-01-01

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

Clustering in large networks does not promote upstream reciprocity.

Directory of Open Access Journals (Sweden)

Naoki Masuda

Full Text Available Upstream reciprocity (also called generalized reciprocity is a putative mechanism for cooperation in social dilemma situations with which players help others when they are helped by somebody else. It is a type of indirect reciprocity. Although upstream reciprocity is often observed in experiments, most theories suggest that it is operative only when players form short cycles such as triangles, implying a small population size, or when it is combined with other mechanisms that promote cooperation on their own. An expectation is that real social networks, which are known to be full of triangles and other short cycles, may accommodate upstream reciprocity. In this study, I extend the upstream reciprocity game proposed for a directed cycle by Boyd and Richerson to the case of general networks. The model is not evolutionary and concerns the conditions under which the unanimity of cooperative players is a Nash equilibrium. I show that an abundance of triangles or other short cycles in a network does little to promote upstream reciprocity. Cooperation is less likely for a larger population size even if triangles are abundant in the network. In addition, in contrast to the results for evolutionary social dilemma games on networks, scale-free networks lead to less cooperation than networks with a homogeneous degree distribution.

Clustering in large networks does not promote upstream reciprocity.

Science.gov (United States)

Masuda, Naoki

2011-01-01

Upstream reciprocity (also called generalized reciprocity) is a putative mechanism for cooperation in social dilemma situations with which players help others when they are helped by somebody else. It is a type of indirect reciprocity. Although upstream reciprocity is often observed in experiments, most theories suggest that it is operative only when players form short cycles such as triangles, implying a small population size, or when it is combined with other mechanisms that promote cooperation on their own. An expectation is that real social networks, which are known to be full of triangles and other short cycles, may accommodate upstream reciprocity. In this study, I extend the upstream reciprocity game proposed for a directed cycle by Boyd and Richerson to the case of general networks. The model is not evolutionary and concerns the conditions under which the unanimity of cooperative players is a Nash equilibrium. I show that an abundance of triangles or other short cycles in a network does little to promote upstream reciprocity. Cooperation is less likely for a larger population size even if triangles are abundant in the network. In addition, in contrast to the results for evolutionary social dilemma games on networks, scale-free networks lead to less cooperation than networks with a homogeneous degree distribution.

Oil and gas site contamination risks : improved oversight needed

International Nuclear Information System (INIS)

2010-02-01

British Columbia has seen record levels of activities in the oil and gas sector. Upstream petroleum processes include exploration, well completion and production. Site contamination can occur during all of these activities, resulting in potential environmental and human health impacts. Although well operators are responsible by law for site restoration, there is a potential risk that some operators will not fulfill their responsibilities, thereby leaving the province liable for the site restoration costs. In British Columbia, the BC Oil and Gas Commission (OGC) is responsible for managing these risks through oversight activities designed to ensure that industry meets its obligations. The OGC also manages the orphan sites reclamation fund. This report presented an audit of the OGC in order to determine if it is providing adequate oversight of upstream oil and gas site contamination risks. The audit examined whether the agency responsibilities are clear and whether the OGC is fully aware of the environmental and financial risks associated with upstream oil and gas site contamination. The audit also examined if the OGC has established appropriate procedures to oversee the risks and to inform the public of how effectively site contamination risks are being managed. The report presented the audit background, audit expectations, findings, conclusions and recommendations. It was concluded that the OGC's oversight of the environmental and financial risks associated with oil and gas site contamination needs improving. tabs., figs.

Long-term observations of regional aerosol composition at two sites in Indonesia

International Nuclear Information System (INIS)

Maenhaut, Willy; De Ridder, Dirk J.A.; Fernandez-Jimenez, Maria-Teresa; Hooper, Martin A.; Hooper, Bev; Nurhayati, Ms

2002-01-01

Aerosol samples were collected with Gent PM10 stacked filter unit (SFU) samplers at Bukit Tinggi, a mountain site on Sumatra, and at Pontianak, a sea-level site on Kalimantan. The Gent PM10 SFU sampler provides two size fractions: coarse (2-10 μm equivalent aerodynamic diameter (EAD)) and fine ( 3 at Bukit Tinggi and Pontianak, respectively. For the fine fraction, the corresponding numbers were 4.5 (2.6-9.1) and 9.4 (6.5-13) μg/m 3 . Principal component analysis was applied to the fine fraction data sets in order to identify the contributing sources (source types). At Bukit Tinggi, five components were identified, i.e., a crustal component, a biomass burning component (with loadings of 0.7-0.9 for BC, K, Br, Rb and I), an oil combustion component (with S and V), a pollution component (with Sb and Pb), and a Na component

Air sampler performance at Ford's farm range

International Nuclear Information System (INIS)

Glissmeyer, J.A.; Johnston, J.W.

1984-07-01

An air-sampling system for a large-caliber depleted uranium (DU) penetrator firing range was tested. The objectives of the test were: to determine the bias between the monitoring readings and DU concentrations; and to determine if the target bay real-time monitor (RTM) tracks the decaying dust concentration. The test procedure was to operate total and respirable airborne particle samplers adjacent to the target bay monitors. A series of air samples was also taken after the test firings adjacent to the target bay RTM. Exhaust particle samples were analyzed for gross alpha, gross beta and uranium content. The target bay RTM correlated well (0.977) with the sequential samples. Average concentration from the RTM did not correlate with either the long-term total or respirable sampler DU concentrations. The monitor used to confirm a low dust concentration when the door is open correlated well (0.810) with the RTM; the other bay monitor did not. In the ventilation discharge, the long-term average monitor readings did not correlate with DU concentrations, probably due to levels near lower detection limits. Smearable surface-contamination samples showed highest contamination on the equipment, gravel floor and exhaust intake. The location air-intake contamination increased over the first 3 rounds. Contamination was reduced by a low-pressure water spray washdown to about the same concentration as often the second round, then remained at about twice the level. 2 references, 18 figures, 16 tables. (MF)

The performance of passive flow monitors and phosphate accumulating passive samplers when exposed to pulses in external water flow rate and/or external phosphate concentrations

International Nuclear Information System (INIS)

O'Brien, Dominique; Hawker, Darryl; Shaw, Melanie; Mueller, Jochen F.

2011-01-01

Passive samplers are typically calibrated under constant flow and concentration conditions. This study assessed whether concentration and/or flow pulses could be integrated using a phosphate passive sampler (P-sampler). Assessment involved three 21-day experiments featuring a pulse in flow rate, a pulse of filterable reactive phosphate (FRP) concentration and a simultaneous concentration and flow pulse. FRP concentrations were also determined by parallel grab sampling and the P-sampler calibrated with passive flow monitors (PFMs) and direct measurement of flow rates. The mass lost from the PFM over the deployment periods predicted water velocity to within 5.1, 0.48 and 7.1% when exposed to a flow rate pulse (7.5-50 cm s -1 ), concentration pulse (5-100 μg P L -1 ), or both simultaneously. For the P-sampler, good agreement was observed between the grab and passive measurements of FRP concentration when exposed to a pulse in flow (6% overestimation) or concentration (2% underestimation). - Highlights: → We assess the performance of the passive flow monitor and a phosphate passive sampler when exposed to changing environmental conditions. → The PFM responded quickly and accurately to a pulse in flow rate but showed little response to an external FRP pulse. → The ability of the sampler to provide an integrated measure of the average phosphate concentrations has been demonstrated. → The results presented demonstrate under which conditions the greatest accuracy is achieved when employing passive samplers. - The performance of an integrative phosphate passive sampler has been assessed when exposed to pulses in flow rate and concentration, both individually and simultaneously.

Retained gas sampler interim safety assessment

Energy Technology Data Exchange (ETDEWEB)

Pasamehmetoglu, K.O.; Miller, W.O.; Unal, C.; Fujita, R.K.

1995-01-13

This safety assessment addresses the proposed action to install, operate, and remove a Retained Gas Sampler (RGS) in Tank 101-SY at Hanford. Purpose of the RGS is to help characterize the gas species retained in the tank waste; the information will be used to refine models that predict the gas-producing behavior of the waste tank. The RGS will take samples of the tank from top to bottom; these samples will be analyzed for gas constituents. The proposed action is required as part of an evaluation of mitigation concepts for eliminating episodic gas releases that result in high hydrogen concentrations in the tank dome space.

Retained gas sampler interim safety assessment

International Nuclear Information System (INIS)

Pasamehmetoglu, K.O.; Miller, W.O.; Unal, C.; Fujita, R.K.

1995-01-01

This safety assessment addresses the proposed action to install, operate, and remove a Retained Gas Sampler (RGS) in Tank 101-SY at Hanford. Purpose of the RGS is to help characterize the gas species retained in the tank waste; the information will be used to refine models that predict the gas-producing behavior of the waste tank. The RGS will take samples of the tank from top to bottom; these samples will be analyzed for gas constituents. The proposed action is required as part of an evaluation of mitigation concepts for eliminating episodic gas releases that result in high hydrogen concentrations in the tank dome space

Evaluation and application of a passive air sampler for polycylic aromatic hydrocarbons (PAHs).

Science.gov (United States)

Esen, Fatma; Evci, Yildiz M; Tasdemir, Yucel

2017-08-24

Sampling of 15 PAHs by the use of both passive air sampler developed (D-PAS) in our research group and PAS (C-PAS) having widespread use in the literature was conducted to compare the performances of the samplers. Sampling was carried out for 1-year period (February 2013-February 2014), in different sampling periods by employing D-PAS and C-PAS. D-PAS and C-PAS were run in parallel for 10, 20, 30, 40 and 60 days. Sampling rates were calculated for both PASs by the use of concentration values obtained from a high-volume air sampler (HVAS). It was determined that calculated sampling values are different from each other by definition of design of C-PAS and D-PAS and difference in environment as velocity of wind and temperature are having different effects upon sampling rates. Collected σ 15 PAHs amounts of 10-day periods in spring, summer, autumn and winter were obtained as 576 ± 333, 209 ± 29, 2402 ± 910 and 664 ± 246 ng for D-PAS and 1070 ± 522, 318 ± 292, 6062 ± 1501 and 6089 ± 4018 ng for C-PAS, respectively. In addition, according to seasons, when collected PAHs in two different samplers were considered, similar results were obtained for the summer time in which no combustion takes place with the aim of domestic heating, while there were differences determined for the seasons with combustion in need of domestic heating. Gas-phase σ 15 PAHs' concentrations were reported depending on seasons in the spring, summer, autumn and winter sequences as 46 ± 32, 9 ± 3, 367 ± 207 and 127 ± 93 ng m -3 for HVAS, respectively.

User's guide for polyethylene-based passive diffusion bag samplers to obtain volatile organic compound concentrations in wells. Part 2, Field tests

Science.gov (United States)

Vroblesky, Don A.

2001-01-01

Diffusion samplers installed in observation wells were found to be capable of yielding representative water samples for chlorinated volatile organic compounds. The samplers consisted of polyethylene bags containing deionized water and relied on diffusion of chlorinated volatile organic compounds through the polyethylene membrane. The known ability of polyethylene to transmit other volatile compounds, such as benzene and toluene, indicates that the samplers can be used for a variety of volatile organic compounds. In wells at the study area, the volatile organic compound concentrations in water samples obtained using the samplers without prior purging were similar to concentrations in water samples obtained from the respective wells using traditional purging and sampling approaches. The low cost associated with this approach makes it a viable option for monitoring large observation-well networks for volatile organic compounds.

A new sampler for simulating aerosol deposition in the respiratory tract

International Nuclear Information System (INIS)

Li Dehong; Zhuo Weihai; Yi Yanling; Chen Bo; Liu Haikuan

2008-01-01

For estimation of the deposition fractions of radon progeny in different regions of the respiratory tract, a new sampler consisting of three different configurations of sampling heads was developed. The deposition fractions of aerosols on the wire screens inside the sampling heads were calculated with the fan model of filtration theory. The deposition fractions of aerosols in different regions of the respiratory tract were calculated with the lung dose evaluation program (LUDEP) developed by National Radiological Protection Board (NRPB) as references. In general indoor and mine environments, the deviation between the deposition fractions of attached aerosol on the wire screens designed in this study and its reference values in the respiratory tract is less than 5%. It is possible to accurately estimate the deposition fractions of radon progeny in different regions of the respiratory tract through mimic measurements of radon progeny collected with the new sampler. (authors)

Participation costs can suppress the evolution of upstream reciprocity.

Science.gov (United States)

Peña, Jorge; Pestelacci, Enea; Berchtold, André; Tomassini, Marco

2011-03-21

Indirect reciprocity, one of the many mechanisms proposed to explain the evolution of cooperation, is the idea that altruistic actions can be rewarded by third parties. Upstream or generalized reciprocity is one type of indirect reciprocity in which individuals help someone if they have been helped by somebody else in the past. Although empirically found to be at work in humans, the evolution of upstream reciprocity is difficult to explain from a theoretical point of view. A recent model of upstream reciprocity, first proposed by Nowak and Roch (2007) and further analyzed by Iwagami and Masuda (2010), shows that while upstream reciprocity alone does not lead to the evolution of cooperation, it can act in tandem with mechanisms such as network reciprocity and increase the total level of cooperativity in the population. We argue, however, that Nowak and Roch's model systematically leads to non-uniform interaction rates, where more cooperative individuals take part in more games than less cooperative ones. As a result, the critical benefit-to-cost ratios derived under this model in previous studies are not invariant with respect to the addition of participation costs. We show that accounting for these costs can hinder and even suppress the evolution of upstream reciprocity, both for populations with non-random encounters and graph-structured populations. Copyright © 2011 Elsevier Ltd. All rights reserved.

Statistical handbook for Canada's upstream petroleum industry: '96 updates

International Nuclear Information System (INIS)

1997-01-01

The Statistical Handbook of CAPP is an annual compilation of useful information about the Canadian petroleum and natural gas industry. It has been published since 1955, and is a key source of upstream petroleum statistics. It presents a historical summary of the petroleum industry''s progress and provides detailed statistical information on the production and consumption of petroleum, petroleum products, natural gas and natural gas liquids, imports and exports, land sales, pipelines, reserves, drilling and refinery activities, and prices in Canada. The information, mostly in tabular form, is based on the latest available data (generally up to and including 1996). For the first time in 1997, the Handbook is also made available in CD-ROM format (EXCEL 5.0). Plans are also underway to publish the Handbook on a secure site on the Internet

Assessment the impact of samplers change on the uncertainty related to geothermalwater sampling

Science.gov (United States)

Wątor, Katarzyna; Mika, Anna; Sekuła, Klaudia; Kmiecik, Ewa

2018-02-01

The aim of this study is to assess the impact of samplers change on the uncertainty associated with the process of the geothermal water sampling. The study was carried out on geothermal water exploited in Podhale region, southern Poland (Małopolska province). To estimate the uncertainty associated with sampling the results of determinations of metasilicic acid (H2SiO3) in normal and duplicate samples collected in two series were used (in each series the samples were collected by qualified sampler). Chemical analyses were performed using ICP-OES method in the certified Hydrogeochemical Laboratory of the Hydrogeology and Engineering Geology Department at the AGH University of Science and Technology in Krakow (Certificate of Polish Centre for Accreditation No. AB 1050). To evaluate the uncertainty arising from sampling the empirical approach was implemented, based on double analysis of normal and duplicate samples taken from the same well in the series of testing. The analyses of the results were done using ROBAN software based on technique of robust statistics analysis of variance (rANOVA). Conducted research proved that in the case of qualified and experienced samplers uncertainty connected with the sampling can be reduced what results in small measurement uncertainty.

A study on air pollution concentration at Desa parkcity construction site

African Journals Online (AJOL)

This study assesses the effect of construction workers exposure towards the air pollution to the correlation between meteorological factor with the particulate matter and other gases concentration at a construction site in DesaParkcity. The concentration of PM was collected by using low volume sampler meanwhile CO, CO2, ...

Comparison of passive soil vapor survey techniques at a Tijeras Arroyo site, Sandia National Laboratories, Albuquerque, New Mexico

International Nuclear Information System (INIS)

Eberle, C.S.; Wade, W.M.; Tharp, T.; Brinkman, J.

1996-01-01

Soil vapor surveys were performed to characterize the approximate location of soil contaminants at a hazardous waste site. The samplers were from two separate companies and a comparison was made between the results of the two techniques. These results will be used to design further investigations at the site

A Compact Diffusion Sampler for Environmental Applications Requiring HTO or HTO + HT Determinations

International Nuclear Information System (INIS)

Otlet, R.L.; Walker, A.J.; Mather, I.D.

2005-01-01

Passive diffusion samplers have now been in use in the UK for the measurement of tritium at environmental levels in the form of HTO and HTO + HT for more than ten years. At the outset their main purpose was to identify the direction of a possible inadvertent release of tritium into the environment. More recently, however, there has been growing interest in their use as stand-alone devices for tritium determination at environmental levels. This has necessitated a more rigorous design to reduce the 'draughts effect' in exposed locations and has also required modifications to enable the measurement of HTO + HT. The paper describes the recent design improvements and the results of validation tests carried out against dynamic, discriminating (dry-bed) samplers

New Rhizon in situ sampler for pore water studies in aquatic sediments: For example nutrient input from submarine groundwater discharge in costal areas.

OpenAIRE

Seeberg-Elverfeldt, J.; Schlüter, Michael; Kölling, M.; Feseker, T.

2005-01-01

To investigate coastal biogeochemical cycles, especially at the sediment/water interface,improved sampling methods are necessary. For this purpose, we developed apore water in situ sampler with miniature sampling devices, so called Rhizons. Rhizonsoil moisture samplers have been used as sampling devices in unsaturated soilsfor the last ten years. In aquatic science they have been rarely used to extract porewater from sediments. This study presents a new developed Rhizon In Situ Sampler(RISS) ...

The determination of volatile chlorinated hydrocarbons in air. Sampling rate and efficiency of diffuse samplers

Energy Technology Data Exchange (ETDEWEB)

Giese, U.; Stenner, H.; Kettrup, A.

1989-05-01

When applicating diffusive sampling-systems to workplace air-monitoring it is necessary to know the behaviour of the diffusive-rate and the efficiency in dependence of concentration, exposition time and the type of pollutant. Especially concerning mixtures of pollutants there are negative influences by competition and mutual displacement possible. Diffusive-rate and discovery for CH/sub 2/Cl/sub 2/ and CHCl/sub 3/ were investigated using two different types of diffuse samplers. For this it was necessary to develop suitable defices for standard gas generation and for the exposition of diffusive-samplers to a standard gas mixture. (orig.).

Analysis of key thresholds leading to upstream dependencies in global transboundary water bodies

Science.gov (United States)

Munia, Hafsa Ahmed; Guillaume, Joseph; Kummu, Matti; Mirumachi, Naho; Wada, Yoshihide

2017-04-01

Transboundary water bodies supply 60% of global fresh water flow and are home to about 1/3 of the world's population; creating hydrological, social and economic interdependencies between countries. Trade-offs between water users are delimited by certain thresholds, that, when crossed, result in changes in system behavior, often related to undesirable impacts. A wide variety of thresholds are potentially related to water availability and scarcity. Scarcity can occur because of the country's own water use, and that is potentially intensified by upstream water use. In general, increased water scarcity escalates the reliance on shared water resources, which increases interdependencies between riparian states. In this paper the upstream dependencies of global transboundary river basins are examined at the scale of sub-basin areas. We aim to assess how upstream water withdrawals cause changes in the scarcity categories, such that crossing thresholds is interpreted in terms of downstream dependency on upstream water availability. The thresholds are defined for different types of water availability on which a sub-basin relies: - reliable local runoff (available even in a dry year), - less reliable local water (available in the wet year), - reliable dry year inflows from possible upstream area, and - less reliable wet year inflows from upstream. Possible upstream withdrawals reduce available water downstream, influencing the latter two water availabilities. Upstream dependencies have then been categorized by comparing a sub-basin's scarcity category across different water availability types. When population (or water consumption) grows, the sub-basin satisfies its needs using less reliable water. Thus, the factors affecting the type of water availability being used are different not only for each type of dependency category, but also possibly for every sub- basin. Our results show that, in the case of stress (impacts from high use of water), in 104 (12%) sub- basins out of

Iowa Developed Energy Activity Sampler (IDEAS), Grades 7-12: Social Studies.

Science.gov (United States)

Simonis, Doris G.

Described is the Social Studies component of the Iowa Developed Energy Activity Sampler (IDEAS), a multidisciplinary energy education program designed for infusion into the curriculum of grades seven through twelve. Aspects of the energy situation addressed in these lessons include resource finiteness, exponential growth, standard of living,…

Valuating Indonesian upstream oil management scenario through system dynamics modelling

Science.gov (United States)

Ketut Gunarta, I.; Putri, F. A.

2018-04-01

Under the existing regulation in Constitution Number 22 Year 2001 (UU No 22 Tahun 2001), Production Sharing Contract (PSC) continues to be the scenario in conducting oil and gas upstream mining activities as the previous regulation (UU No. 8 Tahun 1971). Because of the high costs and risks in upstream mining activities, the contractors are dominated by foreign companies, meanwhile National Oil Company (NOC) doesn’t act much. The domination of foreign contractor companies also warned Indonesia in several issues addressing to energy independence and energy security. Therefore, to achieve the goals of energy which is independence and security, there need to be a revision in upstream oil activities regulating scenario. The scenarios will be comparing the current scenario, which is PSC, with the “full concession” scenario for National Oil Company (NOC) in managing oil upstream mining activities. Both scenario will be modelled using System Dynamics methodology and assessed furthermore using financial valuation method of income approach. Under the 2 scenarios, the author will compare which scenario is better for upstream oil management in reaching the goals mentioned before and more profitable in financial aspect. From the simulation, it is gathered that concession scenario offers better option than PSC in reaching energy independence and energy security.

Inlet effect induced ''upstream'' critical heat flux in smooth tubes

International Nuclear Information System (INIS)

Kitto, J.B. Jr.

1986-01-01

An unusual form of ''upstream'' critical heat flux (CHF) has been observed and directly linked to the inlet flow pattern during an experimental study of high pressure (17 - 20 MPa) water flowing through a vertical 38.1 mm ID smooth bore tube with uniform axial and nonuniform circumferential heating. These upstream CHF data were characterized by temperature excursions which initially occurred at a relatively fixed axial location in the middle of the test section while the outlet and inlet heated lengths experienced no change. A rifled tube inlet flow conditioner could be substituted for a smooth tube section to generate the desired swirling inlet flow pattern. The upstream CHF data were found to match data from a uniformly heated smooth bore tube when the comparison was made using the peak local heat flux. The mechanism proposed to account for the upstream CHF observations involves the destructive interference between the decaying swirl flow and the secondary circumferential liquid flow field resulting from the one-sided heating

The LHCb Upstream Tracker Project

CERN Document Server

Steinkamp, Olaf

2015-01-01

The LHCb detector performs searches for New Physics in CP-violating observables and rare heavy-quark decays at the LHC. A comprehensive upgrade is planned for the long shutdown of the LHC in 2018/19. A goal of this upgrade is to abolish hardware triggers and read out the full detector at 40 MHz. This requires to replace the existing TT station upstream of the LHCb magnet by a new silicon micro-strip detector, the Upstream Tracker (UT). The UT will have a new front-end chip compatible with 40 MHz readout, silicon sensors with improved radiation hardness, finer readout granularity, and improved acceptance coverage at small polar angles. The outer region of each detection layer will be covered by p-in-n sensors with 10 cm long strips and a pitch of about 180 mum, while n-in-p sensors with half the pitch and strip length will be employed in the regions of highest particle density close to the beam pipe. The innermost sensors will have a circular cutout to optimize the forward acceptance. The front-end chip is bei...

Development of a passive sampler based on a polymer inclusion membrane for total ammonia monitoring in freshwaters.

Science.gov (United States)

Almeida, M Inês G S; Silva, Adélia M L; Coleman, Rhys A; Pettigrove, Vincent J; Cattrall, Robert W; Kolev, Spas D

2016-05-01

A passive sampler for determining the time-weighted average total ammonia (i.e. molecular ammonia and the ammonium cation) concentration (C TWA) in freshwaters, which incorporated a polymer inclusion membrane (PIM) as a semi-permeable barrier separating the aqueous source solution from the receiving solution (i.e. 0.8 mol L(-1) HCl), was developed for the first time. The PIM was composed of dinonylnaphthalene sulfonic acid (DNNS) as a carrier, poly (vinyl chloride) (PVC) as a base polymer and 1-tetradecanol as a modifier. Its optimal composition was found to be 35 wt% commercial DNNS, 55 wt% PVC and 10 wt% 1-tetradecanol. The effect of environmental variables such as the water matrix, pH and temperature were also studied using synthetic freshwaters. The passive sampler was calibrated under laboratory conditions using synthetic freshwaters and exhibited a linear response within the concentration range 0.59-2.8 mg L(-1) NH4(+) (0.46-2.1 mg N L(-1)) at 20 °C. The performance of the sampler was further investigated under field conditions over 7 days. A strong correlation between spot sampling and passive sampling was achieved, thus providing a proof-of-concept for the passive sampler for reliably measuring the C(TWA) of total ammonia in freshwaters, which can be used as an indicator in tracking sources of faecal contamination in stormwater drains.

Unified Frequency-Domain Analysis of Switched-Series-RC Passive Mixers and Samplers

NARCIS (Netherlands)

Soer, M.C.M.; Klumperink, Eric A.M.; de Boer, Pieter-Tjerk; van Vliet, Frank Edward; Nauta, Bram

2010-01-01

Abstract—A wide variety of voltage mixers and samplers are implemented with similar circuits employing switches, resistors, and capacitors. Restrictions on duty cycle, bandwidth, or output frequency are commonly used to obtain an analytical expression for the response of these circuits. This paper

Assessing the transport of PAH in the surficial sediment layer by passive sampler approach.

Science.gov (United States)

Belles, Angel; Alary, Claire; Criquet, Justine; Ivanovsky, Anastasia; Billon, Gabriel

2017-02-01

A new method based on passive samplers has been developed to assess the diffusive flux of fluorene, fluoranthene and pyrene in the sediment bed and across the sediment-water interface. The dissolved compound concentration gradient in the sediment in the vertical direction was measured at the outlet of a storm water pond by using polyethylene strips as passive samplers. Simultaneously, the dissipation of a set of tracer compounds preloaded in the passive samplers was measured to estimate the effective diffusion coefficients of the pollutants in the sediment. Both measurements were used to evaluate the diffusive flux of the compounds according to Fick's first law. The diffusive fluxes of the 3 studied compounds have been estimated with a centimetre-scale resolution in the upper 44cm of the sediment. According to the higher compound diffusion coefficient and the steeper concentration gradient in the surficial sediment layer, the results show that the net flux of compounds near the sediment interface (1cm depth) is on average 500 times higher than in the deep sediment, with average fluxes at 1cm depth on the order of 5, 0.1 and 0.1ng/m 2 /y for fluorene, fluoranthene and pyrene, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Wind erosion research at an uranium mill tailings site

International Nuclear Information System (INIS)

Sehmel, G.A.

1977-07-01

A uranium mill tailings pile at Grants, New Mexico, was selected for wind erosion research since the configuration provides flat area containing fine sand and made up of larger particles. The wind erosion experiment is discussed. Experimental equipment consists of meteorological instrumentation to automatically activate air samplers as a function of wind speed increments and direction, particle cascade impactors to measure airborne respirable concentrations as a function of particle size, inertial impaction devices to measure nonrespirable fluxes of airborne particles, a virtual particle cascade impactor to measure airborne concentrations of toxic trace elements, and soil depth gauges to measure changes in surface soil elevations as a function of time. Both radioactive particles as well as toxic trace element concentrations are measured. Radioactive particles are measured with both particle cascade impactors as well as high-volume air samplers. In contrast, toxic trace element airborne concentrations are measured only with a two-stage virtual particle cascade impactor. Fluxes of nonrespirable airborne particles are measured with inertial impaction devices. At particle cascade impactor sites, a rotating cyclone preseparator collects nonrespirable particles. In addition at all sites, fluxes of nonrespirable particles are measured using an open cavity inertial impaction device

Rapid Bioassessment Methods for Assessing Stream Macroinvertebrate Community on the Savannah River Site

International Nuclear Information System (INIS)

Specht, W.L.

1999-01-01

Macroinvertebrate sampling was performed at 16 locations in the Savannah River Site (SRS) streams using Hester-Dendy multiplate samplers and EPA Rapid Bioassessment Protocols (RBP). Some of the sampling locations were unimpacted, while other locations had been subject to various forms of perturbation by SRS activities. In general, the data from the Hester-Dendy multiplate samplers were more sensitive at detecting impacts than were the RBP data. We developed a Biotic Index for the Hester-Dendy data which incorporated eight community structure, function, and balance parameters. when tested using a data set that was unrelated to the data set that was used in developing the Biotic Index, the index was very successful at detecting impact

Rapid Bioassessment Methods for Assessing Stream Macroinvertebrate Community on the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Specht, W.L.

1999-11-22

Macroinvertebrate sampling was performed at 16 locations in the Savannah River Site (SRS) streams using Hester-Dendy multiplate samplers and EPA Rapid Bioassessment Protocols (RBP). Some of the sampling locations were unimpacted, while other locations had been subject to various forms of perturbation by SRS activities. In general, the data from the Hester-Dendy multiplate samplers were more sensitive at detecting impacts than were the RBP data. We developed a Biotic Index for the Hester-Dendy data which incorporated eight community structure, function, and balance parameters. when tested using a data set that was unrelated to the data set that was used in developing the Biotic Index, the index was very successful at detecting impact.

Evaluation of polyurethane foam passive air sampler (PUF) as a tool for occupational PAH measurements.

Science.gov (United States)

Strandberg, Bo; Julander, Anneli; Sjöström, Mattias; Lewné, Marie; Koca Akdeva, Hatice; Bigert, Carolina

2018-01-01

Routine monitoring of workplace exposure to polycyclic aromatic hydrocarbons (PAHs) is performed mainly via active sampling. However, active samplers have several drawbacks and, in some cases, may even be unusable. Polyurethane foam (PUF) as personal passive air samplers constitute good alternatives for PAH monitoring in occupational air (8 h). However, PUFs must be further tested to reliably yield detectable levels of PAHs in short exposure times (1-3 h) and under extreme occupational conditions. Therefore, we compared the personal exposure monitoring performance of a passive PUF sampler with that of an active air sampler and determined the corresponding uptake rates (Rs). These rates were then used to estimate the occupational exposure of firefighters and police forensic specialists to 32 PAHs. The work environments studied were heavily contaminated by PAHs with (for example) benzo(a)pyrene ranging from 0.2 to 56 ng m -3 , as measured via active sampling. We show that, even after short exposure times, PUF can reliably accumulate both gaseous and particle-bound PAHs. The Rs-values are almost independent of variables such as the concentration and the wind speed. Therefore, by using the Rs-values (2.0-20 m 3 day -1 ), the air concentrations can be estimated within a factor of two for gaseous PAHs and a factor of 10 for particulate PAHs. With very short sampling times (1 h), our method can serve as a (i) simple and user-friendly semi-quantitative screening tool for estimating and tracking point sources of PAH in micro-environments and (ii) complement to the traditional active pumping methods. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Performance of a hydrostatic sampler for collecting samples at the water-sediment interface in lakes

Directory of Open Access Journals (Sweden)

Fernando PEDROZO

2008-02-01

Full Text Available The water-sediment interface plays a significant role in the determination of the trophic degree of a waterbody. Numerous redox reactions take place there, resulting in the release of contaminants from the sediments to the water column. The aim of the present work was to develop an equipment for collecting samples from the water-sediment interface. Such equipment was to have a simple design, low construction cost, no depth limitations, and high levels of personal safety and to be reliable in the collection of samples. The performance of the hydrostatic sampler thus developed was tested against samples collected either remotely with a corer or directly with syringes by autonomous divers. The hydrostatic sampler permits access to depths where the costs of the traditional diving methodology are expensive, and where working conditions are dangerous for the diver. The hydrostatic sampler provides an additional means of collecting samples from the water-sediment interface, which together with pore-water samples, facilitates the investigation and understanding of chemical mechanisms in lakes, for instance, those that control the P release from sediment to the water column.

Upstream passage, spawning, and stock identification of fall chinook in the Snake River, 1992 and 1993. Final report

International Nuclear Information System (INIS)

Blankenship, H.L.; Mendel, G.W.

1997-05-01

This final report of the 3-year study summarizes activities and results for 1993. Study objectives were to: (1) determine the source of losses (or accounting errors) for adult chinook salmon between Ice Harbor Dam (IHR) and Lower Granite Dam (LGR), and upstream of LGR in the Snake River; (2) identify spawning locations upstream of LGR for calibration of aerial redd surveys, redd habitat mapping, carcass recovery for genetic stock profile analysis, and correction of estimated adult/redd ratios; and (3) estimate passage and migration times at Snake River. 200 fall chinook salmon were radio tagged and tracked with aerial, fixed-site, and ground mobile tracking. Fish were released upstream of IHR at Charbonneau Park (CHAR). 190 of the fish were tracked or relocated away from CHAR. 59 fish descended to below IHR without crossing Lower Monumental Dam (LMO). Another 128 salmon passed upstream of LMO without falling back at IHR. Only 80 salmon passed Little Goose Dam (LGO) without falling back at a downstream dam; 66 of these fish passed LGR. Many fish that fell back reascended the dams. A total of 72 salmon released at CHAR passed upstream of LGR, including fish that had fallen back and reascended a dam. Over 80 percent of the salmon that entered Lyons Ferry Hatchery each year had reached LGO before descending to the hatchery. Extensive wandering was documented between LMO and upstream of LGR before salmon entered Lyons Ferry Hatchery or the Tucannon River. In 1993, 41 salmon were found to be of hatchery origin when recovered. These fish entered Lyons Ferry Hatchery with similar movements to unmarked salmon. Each year a few salmon have remained near the hatchery without entering, which suggests the hatchery may have inadequate attraction flows. Fall chinook passed lower Snake River dams in 2-5 days each on average. Median travel times through LMO and LGO were 1.0-1.3 days each, which was slower than for spring chinook or steelhead in 1993. 5 refs., 21 figs., 20 tabs

Upstream migration of Pacific lampreys in the John Day River, Oregon: Behavior, timing, and habitat use

Science.gov (United States)

Robinson, T. Craig; Bayer, J.M.

2005-01-01

Adult Pacific lamprey migration and habitat preferences for over-winter holding and spawning, and larval rearing in tributaries to the Columbia River are not well understood. The John Day River is one such tributary where larval and adult stages of this species have been documented, and its free-flowing character provided the opportunity to study migration of Pacific lampreys unimpeded by passage constraints. Forty-two adult Pacific lampreys were captured in the John Day River near its mouth during their upstream migration. Pacific lampreys were surgically implanted with radio transmitters and released onsite, and tracked by fixed-site, aerial, and terrestrial telemetry methods for nearly one year. Adults moved upstream exclusively at night, with a mean rate of 11.1 ?? 6.3 km/day. They halted upstream migration by September, and held a single position for approximately six months in the lateral margins of riffles and glides, using boulders for cover. More than half of Pacific lampreys resumed migration in March before ending movement in early May. Pacific lampreys that resumed migration in spring completed a median of 87% of their upstream migration before over-winter holding. Upon completing migration. Pacific lampreys briefly held position before beginning downstream movement at the end of May. Though not directly observed, halting migration and movement downstream were likely the result of spawning and death. Gains in adult Pacific lamprey passage through the Columbia River hydrosystem and tributaries may be made by improvements that would expedite migration during spring and summer and increase the quantity and variety of cover and refuge opportunities. ?? 2005 by the Northwest Scientific Association. All rights reserved.

Upstream waves simultaneously observed by ISEE and UKS

International Nuclear Information System (INIS)

Russell, C.T.; Luhmann, J.G.; Elphic, R.C.; Southwood, D.J.; Smith, M.F.; Johnstone, A.D.

1987-01-01

Measurements obtained in the solar wind by ISEE-2 and the United Kingdom Subsatellite (UKS) have been examined for observations of upstream waves. These data reveal that the waves in the foreshock region are enhanced at all frequencies from at least 0.003 Hz to 0.5 Hz. The wave spectra generally have a spectral peak, but this peak is usually broad and the peak frequency depends on the position of the spacecraft. Generally, the spectra seen at the two spacecraft are most similar at high frequencies and least similar at low frequencies. The geometry of the interaction is displayed in the plane containing the magnetic field, the solar wind velocity, and the spacecraft location. However, this coordinate system does not order all the observed wave properties. It does not clearly explain or order the handedness of the waves, or their direction of propagation. It is clear that the upstream region is inherently three-dimensional. The position-dependent nature of the upstream waves indicates that comparisons between ground-based measurements and in-situ observations must be undertaken with some caution

Meeting the challenge : capturing the upstream

International Nuclear Information System (INIS)

Bogle, E.W.

1998-01-01

The challenge facing the exploration and production sector of the petroleum industry to capture and hold onto the upstream was the main focus of this paper. The exploration and production (E and P) business was described as being highly complex, characterized by constant change and increasing competition. Some of the dynamic changes which have occurred in the Western Canada Basin (WCB) during the last five years and how they relate to the international playing field were reviewed. Significant changes to the production ranking profile as a result of acquisitions, and basin reserve endowment and maturity are the two major factors affecting current and future dynamics of upstream WCB E and P activity. Competitive pressures, contractor relationships, infrastructure access and controls, environmental issues are some of the other factors. Taking these factors into account, Talisman Energy Inc. has used its growth in the WCB to leverage its international activities, diversifying to less mature, but proven hydrocarbon basins. The company's international exploration strategy is designed to be adaptive and flexible and is guided by focus on a limited number of core areas with proven source rock and existing production, achievement of a set production level within a five-year time frame, ensuring strong relationships with host governments and partners, and selecting areas where a multiple of opportunity types are available. In general, for any upstream company it is important to recognize that the more predictable traditional order has given way to a market-driven environment where the rules change almost daily, and success depends on the ability to adapt to change.14 figs

Design of data sampler in intelligent physical start-up system for nuclear reactor

International Nuclear Information System (INIS)

Wang Yinli; Ling Qiu

2007-01-01

It introduces the design of data sampler in intelligent physical start-up system for nuclear reactor. The hardware frame taking STμPSD3234A as the core and the firmware design based on USB interface are discussed. (authors)

Concentrations, Trends, and Air-Water Exchange of PAHs and PBDEs Derived from Passive Samplers in Lake Superior in 2011.

Science.gov (United States)

Ruge, Zoe; Muir, Derek; Helm, Paul; Lohmann, Rainer

2015-12-01

Polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenylethers (PBDEs) are both currently released into the environment from anthropogenic activity. Both are hence primarily associated with populated or industrial areas, although wildfires can be an important source of PAHs, as well. Polyethylene passive samplers (PEs) were simultaneously deployed in surface water and near surface atmosphere to determine spatial trends and air-water gaseous exchange of 21 PAHs and 11 PBDEs at 19 sites across Lake Superior in 2011. Surface water and atmospheric PAH concentrations were greatest at urban sites (up to 65 ng L(-1) and 140 ng m(-3), respectively, averaged from June to October). Near populated regions, PAHs displayed net air-to-water deposition, but were near equilibrium off-shore. Retene, probably depositing following major wildfires in the region, dominated dissolved PAH concentrations at most Lake Superior sites. Atmospheric and dissolved PBDEs were greatest near urban and populated sites (up to 6.8 pg L(-1) and 15 pg m(-3), respectively, averaged from June to October), dominated by BDE-47. At most coastal sites, there was net gaseous deposition of BDE-47, with less brominated congeners contributing to Sault Ste. Marie and eastern open lake fluxes. Conversely, the central open lake and Eagle Harbor sites generally displayed volatilization of PBDEs into the atmosphere, mainly BDE-47.

Passive sampling of selected endocrine disrupting compounds using polar organic chemical integrative samplers

International Nuclear Information System (INIS)

Arditsoglou, Anastasia; Voutsa, Dimitra

2008-01-01

Two types of polar organic chemical integrative samplers (pharmaceutical POCIS and pesticide POCIS) were examined for their sampling efficiency of selected endocrine disrupting compounds (EDCs). Laboratory-based calibration of POCISs was conducted by exposing them at high and low concentrations of 14 EDCs (4-alkyl-phenols, their ethoxylate oligomers, bisphenol A, selected estrogens and synthetic steroids) for different time periods. The kinetic studies showed an integrative uptake up to 28 days. The sampling rates for the individual compounds were obtained. The use of POCISs could result in an integrative approach to the quality status of the aquatic systems especially in the case of high variation of water concentrations of EDCs. The sampling efficiency of POCISs under various field conditions was assessed after their deployment in different aquatic environments. - Calibration and field performance of polar organic integrative samplers for monitoring EDCs in aquatic environments

Experimental typing of the entry efficiency in calm air of an annular slot sampler; Determination experimentale de l'efficacite de captage en air calme d'un echantillonneur a fente annulaire

Energy Technology Data Exchange (ETDEWEB)

Roger, F.; Fabries, J.F.; Gorner, P.; Wrobel, R. [Institut National de Recherche et de Securite, INRS, Lab. de Metrologie de la Pollution par les Aerosols, 54 - Vandoeuvre-Les-Nancy (France); Renoux, A. [Paris-12 Univ., Lab. de Physique des Aerosols et de Transfert des Contaminations, 94 - Creteil (France)

2000-07-01

Aerosol sampling is a complex physical process that depends on many parameters like particle size, wind speed, aspiration velocity and sampler geometry. Inertia has a predominant influence on particle motion in moving air for particle size above 1 {mu}m. In calm air where air movement is mainly induced by the aspiration orifice of the sampler, gravitational settling affects more deeply particle motion and hence sampler performance. The entry efficiency of a sampler with an annular aspiration slot was recently measured for several conditions of aspiration flow rate, wind speed (1 and 3 m s{sup -1}) and geometric parameters of the sampler as a function of particle aerodynamic diameter. Some complementary work was carried out to add new experimental data corresponding to the same sampler in calm air. The results were obtained for 9 configurations, combining several values of disc diameter, aspiration slot width, and aspiration velocity. A semi-empirical model was developed from the data that enables the calculation of particle entry efficiency of the annular sampler in calm air. In addition, a numerical study was carried out to calculate the particle trajectories approaching the annular aspiration slot of the sampler. The results show that particle rebounds on the sampler walls have a significant effect on the entry efficiency of the sampler in calm air. (authors)

Evaluation of a depth proportional intake device for automatic pumping samplers

Science.gov (United States)

Rand E. Eads; Robert B. Thomas

1983-01-01

Abstract - A depth proportional intake boom for portable pumping samplers was used to collect suspended sediment samples in two coastal streams for three winters. The boom pivots on the stream bed while a float on the downstream end allows debris to depress the boom and pass without becoming trapped. This equipment modifies point sampling by maintaining the intake...

Spatial distribution of upstream magnetospheric ≥50 keV ions

Directory of Open Access Journals (Sweden)

G. C. Anagnostopoulos

2000-01-01

Full Text Available We present for the first time a statistical study of \\geq50 keV ion events of a magnetospheric origin upstream from Earth's bow shock. The statistical analysis of the 50-220 keV ion events observed by the IMP-8 spacecraft shows: (1 a dawn-dusk asymmetry in ion distributions, with most events and lower intensities upstream from the quasi-parallel pre-dawn side (4 LT-6 LT of the bow shock, (2 highest ion fluxes upstream from the nose/dusk side of the bow shock under an almost radial interplanetary magnetic field (IMF configuration, and (3 a positive correlation of the ion intensities with the solar wind speed and the index of geomagnetic index Kp, with an average solar wind speed as high as 620 km s-1 and values of the index Kp > 2. The statistical results are consistent with (1 preferential leakage of ~50 keV magnetospheric ions from the dusk magnetopause, (2 nearly scatter free motion of ~50 keV ions within the magnetosheath, and (3 final escape of magnetospheric ions from the quasi-parallel dawn side of the bow shock. An additional statistical analysis of higher energy (290-500 keV upstream ion events also shows a dawn-dusk asymmetry in the occurrence frequency of these events, with the occurrence frequency ranging between ~16%-~34% in the upstream region.Key words. Interplanetary physics (energetic particles; planetary bow shocks

Spatial distribution of upstream magnetospheric ≥50 keV ions

Directory of Open Access Journals (Sweden)

G. Kaliabetsos

Full Text Available We present for the first time a statistical study of geq50 keV ion events of a magnetospheric origin upstream from Earth's bow shock. The statistical analysis of the 50-220 keV ion events observed by the IMP-8 spacecraft shows: (1 a dawn-dusk asymmetry in ion distributions, with most events and lower intensities upstream from the quasi-parallel pre-dawn side (4 LT-6 LT of the bow shock, (2 highest ion fluxes upstream from the nose/dusk side of the bow shock under an almost radial interplanetary magnetic field (IMF configuration, and (3 a positive correlation of the ion intensities with the solar wind speed and the index of geomagnetic index Kp, with an average solar wind speed as high as 620 km s-1 and values of the index Kp > 2. The statistical results are consistent with (1 preferential leakage of ~50 keV magnetospheric ions from the dusk magnetopause, (2 nearly scatter free motion of ~50 keV ions within the magnetosheath, and (3 final escape of magnetospheric ions from the quasi-parallel dawn side of the bow shock. An additional statistical analysis of higher energy (290-500 keV upstream ion events also shows a dawn-dusk asymmetry in the occurrence frequency of these events, with the occurrence frequency ranging between ~16%-~34% in the upstream region.Key words. Interplanetary physics (energetic particles; planetary bow shocks

A novel method for sampling the suspended sediment load in the tidal environment using bi-directional time-integrated mass-flux sediment (TIMS) samplers

Science.gov (United States)

Elliott, Emily A.; Monbureau, Elaine; Walters, Glenn W.; Elliott, Mark A.; McKee, Brent A.; Rodriguez, Antonio B.

2017-12-01

Identifying the source and abundance of sediment transported within tidal creeks is essential for studying the connectivity between coastal watersheds and estuaries. The fine-grained suspended sediment load (SSL) makes up a substantial portion of the total sediment load carried within an estuarine system and efficient sampling of the SSL is critical to our understanding of nutrient and contaminant transport, anthropogenic influence, and the effects of climate. Unfortunately, traditional methods of sampling the SSL, including instantaneous measurements and automatic samplers, can be labor intensive, expensive and often yield insufficient mass for comprehensive geochemical analysis. In estuaries this issue is even more pronounced due to bi-directional tidal flow. This study tests the efficacy of a time-integrated mass sediment sampler (TIMS) design, originally developed for uni-directional flow within the fluvial environment, modified in this work for implementation the tidal environment under bi-directional flow conditions. Our new TIMS design utilizes an 'L' shaped outflow tube to prevent backflow, and when deployed in mirrored pairs, each sampler collects sediment uniquely in one direction of tidal flow. Laboratory flume experiments using dye and particle image velocimetry (PIV) were used to characterize the flow within the sampler, specifically, to quantify the settling velocities and identify stagnation points. Further laboratory tests of sediment indicate that bidirectional TIMS capture up to 96% of incoming SSL across a range of flow velocities (0.3-0.6 m s-1). The modified TIMS design was tested in the field at two distinct sampling locations within the tidal zone. Single-time point suspended sediment samples were collected at high and low tide and compared to time-integrated suspended sediment samples collected by the bi-directional TIMS over the same four-day period. Particle-size composition from the bi-directional TIMS were representative of the array of

PERFORMANCE OF A NEW DIFFUSIVE SAMPLER FOR HG0 DETERMINATION IN THE TROPOSPHERE

Science.gov (United States)

Mercury behaves uniquely in the atmosphere due to its volatility and long lifetime. The existing methods for measuring atmospheric mercury are either expensive or labour intensive. The present paper presents a new measurement technique, the diffusive sampler, that is portable, in...

Combining polar organic chemical integrative samplers (POCIS) with toxicity testing to evaluate pesticide mixture effects on natural phototrophic biofilms

International Nuclear Information System (INIS)

Pesce, Stephane; Morin, Soizic; Lissalde, Sophie; Montuelle, Bernard; Mazzella, Nicolas

2011-01-01

Polar organic chemical integrative samplers (POCIS) are valuable tools in passive sampling methods for monitoring polar organic pesticides in freshwaters. Pesticides extracted from the environment using such methods can be used to toxicity tests. This study evaluated the acute effects of POCIS extracts on natural phototrophic biofilm communities. Our results demonstrate an effect of POCIS pesticide mixtures on chlorophyll a fluorescence, photosynthetic efficiency and community structure. Nevertheless, the range of biofilm responses differs according to origin of the biofilms tested, revealing spatial variations in the sensitivity of natural communities in the studied stream. Combining passive sampler extracts with community-level toxicity tests offers promising perspectives for ecological risk assessment. - Research highlights: → Polar organic chemical integrative samplers (POCIS) were used for monitoring polar organic pesticides in a contaminated river. → The acute effects of POCIS extracts were tested on natural phototrophic biofilm communities. → POCIS pesticide mixtures affected chlorophyll a fluorescence, photosynthetic efficiency and community structure. → Biofilm responses differed according to origin of the biofilms tested, revealing variations in the sensitivity of natural communities. → Combining passive sampler extracts with community-level toxicity tests offers promising perspectives for ecological risk assessment. - Pesticide mixtures extracted from POCIS can affect chl a fluorescence, photosynthetic efficiency and community structure of natural biofilms.

LHCb upstream tracker

CERN Multimedia

Artuso, Marina

2016-01-01

The detector for the LHCb upgrade is designed for 40MHz readout, allowing the experiment to run at an instantaneous luminosity of 2x10^33 cm$^2$s$^-1$. The upgrade of the tracker subsystem in front of the dipole magnet, the Upstream Tracker, is crucial for charged track reconstruction and fast trigger decisions based on a tracking algorithm involving also vertex detector information. The detector consists of 4 planes with a total area of about 8.5m$^2$, made of single sided silicon strip sensors read-out by a novel custom-made ASIC (SALT). Details on the performance of prototype sensors, front-end electronics, near-detector electronics and mechanical components are presented.

Measurement of volatile organic compounds during start-up of bioremediation of French limited superfund site in Crosby Texas using wind dependent whole-air sampling

International Nuclear Information System (INIS)

Pleil, J.D.; Fortune, C.R.; Yoong, M.; Oliver, K.D.

1993-01-01

Whole-air sampling was performed before and after the start-up of the bioremediation of an industrial (primarily petrochemical) waste lagoon in Crosby Texas, near Houston. Four 'Sector Samplers' were deployed at the four corners of the French Limited Superfund Site. These samplers collect air into one of two SUMMA polished canisters depending upon wind direction and speed. When the wind blows at the sampler from across the waste lagoon, air is routed to the 'IN' sector canister, otherwise sample is collected in the 'OUT' sector canister. As such, each sampler provides its own background sample, and, upon gas chromatographic analysis, individual compounds can be associated with the waste lagoon. Five sets of 24-hour sector samples were taken; the first set was collected prior to the start of the bioremediation effort and the remaining four sets were taken sequentially for four 24-hour periods after the start-up of the procedure

Spectrometric study of the folding process of i-motif-forming DNA sequences upstream of the c-kit transcription initiation site

International Nuclear Information System (INIS)

Bucek, Pavel; Gargallo, Raimundo; Kudrev, Andrei

2010-01-01

The c-kit oncogene shows a cytosine-rich DNA region upstream of the transcription initiation site which forms an i-motif structure at slightly acidic pH values (Bucek et al. ). In the present study, the pH-induced formation of i-motif - forming sequences 5'-CCC CTC CCT CGC GCC CGC CCG-3' (ckitC1, native), 5'-CCC TTC CCT TGT GCC CGC CCG-3' (ckitC2) and 5'-CCCTT CCC TTTTT CCC T CCC T-3' (ckitC3) was studied by spectroscopic techniques, such as UV molecular absorption and circular dichroism (CD), in tandem with two multivariate data analysis methods, the hard modelling-based matrix method and the soft modelling-based MCR-ALS approach. Use of the hard chemical modelling enabled us to propose the equilibrium model, which describes spectral changes as functions of solution acidity. Additionally, the intrinsic protonation constant, K in , and the cooperativity parameters, ω c , and ω a , were calculated from the fitting procedure of the coupled CD and molecular absorption spectra. In the case of ckitC2 and ckitC3, the hard model correctly reproduced the spectral variations observed experimentally. The results indicated that folding was accompanied by a cooperative process, i.e. the enhancement of protonated structure stability upon protonation. In contrast, unfolding was accompanied by an anticooperative process. Finally, folding of the native sequence, ckitC1, seemed to follow a more complex mechanism.

Investigation of the tritium release from Building 324 in which the stack tritium sampler was off, April 14 through 17, 1998

International Nuclear Information System (INIS)

Brown, D.H.

1998-01-01

On April 14, 1998, a Pacific Northwest National Laboratory (PNNL) researcher performing work in the Building 324 facility approached facility management and asked if facility management could turn off the tritium sampler in the main exhaust stack. The researcher was demonstrating the feasibility of treating components from dismantled nuclear weapons in a device called a plasma arc furnace and was concerned that the sampler would compromise classified information. B and W Hanford Company (BWHC) operated the facility, and PNNL conducted research as a tenant in the facility. The treatment of 200 components in the furnace would result in the release of up to about 20 curies of tritium through the facility stack. The exact quantity of tritium was calculated from the manufacturing data for the weapons components and was known to be less than 20 curies. The Notice of Construction (NOC) approved by the Washington State Department of Health (WDOH) had been modified to allow releasing 20 curies of tritium through the stack in support of this research. However, there were irregularities in the way the NOC modification was processed. The researcher was concerned that data performed on the sampler could be used to back-calculate the tritium content of the components, revealing classified information about the design of nuclear weapons. He had discussed this with the PNNZ security organization, and they had told him that data from the sampler would be classified. He was also concerned that if he could not proceed with operation of the plasma arc furnace, the furnace would be damaged. The researcher told BWHC management that the last time the furnace was shut down and restarted it had cost $0.5 million and caused a six month delay in the project's schedule. He had already begun heating up the furnace before recognizing the security problem and was concerned that stopping the heatup could damage the furnace. The NOC that allowed the research did not have an explicit requirement to

Inventories and upstream gasoline price dynamics

NARCIS (Netherlands)

Kuper, Gerard H.

This paper sheds new light on the asymmetric dynamics in upstream U.S. gasoline prices. The model is based on Pindyck's inventory model of commodity price dynamics. We show that asymmetry in gasoline price dynamics is caused by changes in the net marginal convenience yield: higher costs of marketing

Development of a new passive sampler based on diffusive milligel beads for copper analysis in water.

Science.gov (United States)

Perez, M; Reynaud, S; Lespes, G; Potin-Gautier, M; Mignard, E; Chéry, P; Schaumlöffel, D; Grassl, B

2015-08-26

A new passive sampler was designed and characterized for the determination of free copper ion (Cu(2+)) concentration in aqueous solution. Each sampling device was composed of a set of about 30 diffusive milligel (DMG) beads. Milligel beads with incorporated cation exchange resin (Chelex) particles were synthetized using an adapted droplet-based millifluidic process. Beads were assumed to be prolate spheroids, with a diameter of 1.6 mm and an anisotropic factor of 1.4. The milligel was controlled in chemical composition of hydrogel (monomer, cross-linker, initiator and Chelex concentration) and characterized in pore size. Two types of sampling devices were developed containing 7.5% and 15% of Chelex, respectively, and 6 nm pore size. The kinetic curves obtained demonstrated the accumulation of copper in the DMG according to the process described in the literature as absorption (and/or adsorption) and release following the Fick's first law of diffusion. For their use in water monitoring, the typical physico-chemical characteristics of the samplers, i.e. the mass-transfer coefficient (k0) and the sampler-water partition coefficient (Ksw), were determined based on a static exposure design. In order to determine the copper concentration in the samplers after their exposure, a method using DMG bead digestion combined to Inductively Coupled Plasma - Atomic Emission Spectrometry (ICP-AES) analysis was developed and optimized. The DMG devices proved to be capable to absorb free copper ions from an aqueous solution, which could be accurately quantified with a mean recovery of 99% and a repeatability of 7% (mean relative uncertainty). Copyright © 2015 Elsevier B.V. All rights reserved.

BCE selector valves and flow proportional sampler

International Nuclear Information System (INIS)

Rippy, G.L.

1994-01-01

This Acceptance Test Procedure (ATP) has been prepared to demonstrate that the Electrical/Instrumentation systems for the B-Plant Process Condensate Treatment Facility (BCE) function as required by project criteria. Tests will be run to: Verify the operation of the solenoid valve and associated limit switches installed for the BCE portion of W-007H; Operate the solenoid valve and verify the proper operation of the associated limit switches based on the position of the solenoid valve;and, Demonstrate the integrity of the Sample Failure Alarm Relay XFA-211BA-BCE-1, and Power Failure ALarm Relay JFA-211BA-BCE-1 located inside the Flow Proportional Sampler in Building 211 BA

Calibration sources for the G-M counter used with the BNL air sampler

International Nuclear Information System (INIS)

Huchton, R.L.; Bird, S.K.; Tkachyk, J.W.; Motes, B.G.

1983-12-01

Three calibration sources were designed, developed, and fabricated for a CDV-700 ratemeter equipped with a specially-shielded 6306 G-M detector. The CDV-700/6306 has been proposed for use with the BNL Air Sampler designed for radioiodine monitoring upon a nuclear reactor accident. Specifically, three sources were constructed in a geometry identical to the BNL Air Sampler radioiodine adsorption canister, which is a silver-silica-gel filled 2.75-inch diameter right circular cylinder with a 1.0 inch daimater annulus for insertion of the 6306 G-M detector. As fabricated, each source consisted of an outer stainless steel housing, an inner 133 Ba impregnated polyester liner, 4 weight percent silver steel lid. Respectively, the levels of 133 Ba, an 131 I simulant, were varied in the three sources to yield nominal CDV-700/6306 instrument responses of 200 cpm, 2000 cpm, and 20,000 cpm

Upstream-downstream cooperation approach in Guanting Reservoir watershed.

Science.gov (United States)

Yang, Zhi-Feng; Zhang, Wen-Guo

2005-01-01

A case study is introduced and discussed concerning water dispute of misuse and pollution between up- and down-stream parts. The relations between water usage and local industrial structures are analyzed. Results show it is important to change industrial structures of the target region along with controlling water pollution by technical and engineering methods. Three manners of upstream-downstream cooperation are presented and discussed based on the actual conditions of Guangting Reservoir watershed. Two typical scenarios are supposed and studied along with the local plan on water resources development. The best solution for this cooperation presents a good way to help the upstream developing in a new pattern of eco-economy.

Suspension, abandonment, decontamination, and surface land reclamation of upstream oil and gas facilities : informational letter IL 98-2

International Nuclear Information System (INIS)

1998-01-01

This release of the Alberta Energy and Utilities Board (EUB) is intended to clarify the jurisdictional roles of Alberta Environmental Protection (AEP) and the EUB with regard to their respective responsibilities for the regulation of the suspension, abandonment, decontamination and surface land reclamation of active and inactive upstream oil and gas facilities. The EUB, AEP and industrial operators all have separate roles and responsibilities when active and inactive upstream facilities are suspended or reclaimed. In the future, industry operators will have more interaction with the AEP during the decontamination of a site, while the EUB will concentrate on pollution prevention and abandonment of non-economic facilities. All oilfield waste generated from suspension, abandonment, decontamination, and surface land reclamation of an active or inactive upstream oil and gas facility will fall under the jurisdiction of the EUB. Contaminated soils, sludges, and waters that are physically removed as a result of decontamination activities are considered to be oilfield wastes. The regulatory responsibility between the AEP and the EUB remains unchanged for the reclamation process of on-lease and off-lease spills, releases or pipeline breaks. Industry operators are no longer allowed to discharge any produced liquid to earthen pits or ponds and are encouraged to reclaim existing ones. 3 figs

Remediation options and treatment for Tebuthiuron at an upstream oil and gas site

Energy Technology Data Exchange (ETDEWEB)

Lin, F. [EBA Engineering Consultants Ltd., Edmonton, AB (Canada)

2009-07-01

Sterilants are strong herbicides that contain teburithion, a substance of concern in remediation and reclamation activities. Tebuthiuron has very high to low mobility in soils, and its sorption capacity increases in relation to clay and organic matter content. There is currently no soil benchmark for sterilants. Remedial options for tebuthiuron include adsorption with amendments, thermal desorption, and soil flushing with injected solutions. A recent pilot plant successfully used thermal desorption to treat soil contaminated with tebuthiuron and bromacil to below laboratory detection limits. Surface soils at the site were contaminated to a depth of 4 m. A temperature ramping study was performed to determine optimal treatment temperatures. A total of 15,136 tonnes of soil were treated and then used as backfill on-site. Water at the site was monitored and treated with charcoal filters. Hydrocarbon-contaminated soil at the site was also successfully treated using the thermal desorption process. tabs., figs.

Silicone Wristband Passive Samplers Yield Highly Individualized Pesticide Residue Exposure Profiles.

Science.gov (United States)

Aerts, Raf; Joly, Laure; Szternfeld, Philippe; Tsilikas, Khariklia; De Cremer, Koen; Castelain, Philippe; Aerts, Jean-Marie; Van Orshoven, Jos; Somers, Ben; Hendrickx, Marijke; Andjelkovic, Mirjana; Van Nieuwenhuyse, An

2018-01-02

Monitoring human exposure to pesticides and pesticide residues (PRs) remains crucial for informing public health policies, despite strict regulation of plant protection product and biocide use. We used 72 low-cost silicone wristbands as noninvasive passive samplers to assess cumulative 5-day exposure of 30 individuals to polar PRs. Ethyl acetate extraction and LC-MS/MS analysis were used for the identification of PRs. Thirty-one PRs were detected of which 15 PRs (48%) were detected only in worn wristbands, not in environmental controls. The PRs included 16 fungicides (52%), 8 insecticides (26%), 2 herbicides (6%), 3 pesticide derivatives (10%), 1 insect repellent (3%), and 1 pesticide synergist (3%). Five detected pesticides were not approved for plant protection use in the EU. Smoking and dietary habits that favor vegetable consumption were associated with higher numbers and higher cumulative concentrations of PRs in wristbands. Wristbands featured unique PR combinations. Our results suggest both environment and diet contributed to PR exposure in our study group. Silicone wristbands could serve as sensitive passive samplers to screen population-wide cumulative dietary and environmental exposure to authorized, unauthorized and banned pesticides.

Multipurpose sampler device for liquid metal

International Nuclear Information System (INIS)

Nelson, P.A.; Kolba, V.M.; Holmes, J.T.

1975-01-01

A device for collecting samples or examining a flow of liquid metal is provided for use with such as a liquid-metal-cooled nuclear reactor. The sampler device includes a casing surrounded by an external heater for establishing an upper isothermal zone and a lower zone for heating the entering liquid metal. One of various inserts is suspended into the isothermal zone where it is surrounded by a shroud tube for directing liquid-metal flow from the heating zone into the top of the insert. Discharge flow from the insert gravitates through a helically wound tube in heat exchange contact with entering liquid-metal flow within the heating zone. The inserts comprise an overflow cup with upper and lower freeze seals, a filter for removing particulate matter, and a fixture for maintaining various sample materials in equilibrium with liquid-metal flow. (U.S.)

Interferon-induced transcription of a gene encoding a 15-kDA protein depends on an upstream enhancer element

International Nuclear Information System (INIS)

Reich, N.; Evans, B.; Levy, D.; Fahey, D.; Knight, E. Jr.; Darnell, J.E. Jr.

1987-01-01

A human gene encoding an interferon-induced 15-kDa protein has been isolated from a genomic library. The gene appears to be single-copy and is composed of two exons, the first of which contains the ATG translation initiation codon. In vitro nuclear run-on assays showed that the transcription rate of the gene is stimulated after interferon treatment. To analyze transcriptional regulatory sequences, the authors constructed recombinant plasmids for use in transient transfection assays of HeLa cells. Constructs containing 115 nucleotides 5' to the transcription initiation site were found to be fully inducible by interferon. Assays of deletion mutants identified a critical element for interferon induction located between -115 and -96, just upstream of the CCAAT box. Moreover, a DNA fragment including this region can confer interferon inducibility on a heterologous promoter (thymidine kinase) when cloned in either orientation upstream of the gene or downstream of the gene. These are properties characteristic of an enhancer element that is active only after treatment with interferon. This regulatory sequence may be shared by a group of interferon-induced genes, since a very similar sequence is present within the functional region near the RNA start site of another interferon-induced gene

Upstream magnetospheric ion flux tube within a magnetic cloud: Wind/STICS

Science.gov (United States)

Posner, Arik; Liemohn, Michael W.; Zurbuchen, Thomas H.

2003-03-01

We present a case study of a remarkable upstream O+ and N+ ion outflow event. We present observational evidence for spatially structured outflow of these Low Charge State Heavy Ions (LCSHIs) of magnetospheric origin along a small reconnected field line region within the framework of a magnetic cloud of an ICME. From the particles' in situ 3D distribution function we conclude that in this case the interaction of the outflow with the bow shock is small. We conclude further that the gyrophases of outflowing ions at the reconnection point are randomly distributed. This leads to the formation of a flux tube with a specific geometry. In particular, the outflow reveals spatial dispersion and non-gyrotropy. This result has implications for the size of the dayside reconnection site.

Responses of low pressure Andersen sampler for collecting substrates

Energy Technology Data Exchange (ETDEWEB)

Yamasaki, K. [Research Reactor Institute, Kyoto University, Osaka (Japan); Yamada, Y.; Miyamoto, K.; Shimo, M. [Division of Radiotoxicology and Protection, National Institute of Radiological Sciences, Chiba (Japan)

2000-05-01

Some types of low pressure cascade impactors (Andersen, Berner, Davies, and MOUDI etc) have been used to measure the activity size distribution of radon progeny in the environment. In spite of their careful uses, their nonideal responses are not adequately known. Some important factors such as the wall loss, electrostatic attraction, and the surface nature of collecting substrates may affect the reliability of the impactor data. Size selective characteristics of a low pressure Andersen sampler for various collecting substrates were examined in a radon exposure chamber using several kinds of liquid (DOS) or solid (carnauba wax) carrier aerosols labelled with radon progeny. These carrier aerosols were produced by commercial condensation aerosol generator. Tested collecting substrates were, (1) uncoated clean stainless steel plate, (2) silicone oil or grease coated stainless steel plate, (3) polyethylene sheet covered stainless steel plate, (4) membrane filter, (5) glass fiber filter, and (6) quartz fiber filter. In the case of collecting liquid or sticky carrier aerosols, the effect of particle bounce was small and nearly any substrates might used on the impaction plate. On the other hand, in the case of solid carrier aerosols, an adhesive layer such as grease or oil might have to be applied to the substrate. It was concluded that a low pressure cascade impactor such as Andersen sampler might need an appropriate calibration procedure including the interstage characteristics for determining the accurate activity size distribution. (author)

Comparison of POCIS passive samplers vs. composite water sampling: A case study.

Science.gov (United States)

Criquet, Justine; Dumoulin, David; Howsam, Michael; Mondamert, Leslie; Goossens, Jean-François; Prygiel, Jean; Billon, Gabriel

2017-12-31

The relevance of Polar Organic Chemical Integrative Samplers (POCIS) was evaluated for the assessment of concentrations of 46 pesticides and 19 pharmaceuticals in a small, peri-urban river with multi-origin inputs. Throughout the period of POCIS deployment, 24h-average water samples were collected automatically, and showed the rapid temporal evolution of concentrations of several micropollutants, as well as permitting the calculation of average concentrations in the water phase for comparison with those estimated from POCIS passive samplers. In the daily water samples, cyproconazol, epoxyconazol and imidacloprid showed high temporal variations with concentrations ranging from under the limit of detection up to several hundreds of ngL -1 . Erythromycin, cyprofloxacin and iopromide also increased rapidly up to tens of ngL -1 within a few days. Conversely, atrazine, caffeine, diclofenac, and to a lesser extent carbamazepine and sucralose, were systematically present in the water samples and showed limited variation in concentrations. For most of the substances studied here, the passive samplers gave reliable average concentrations between the minimal and maximal daily concentrations during the time of deployment. For pesticides, a relatively good correlation was clearly established (R 2 =0.89) between the concentrations obtained by POCIS and those gained from average water samples. A slight underestimation of the concentration by POCIS can be attributed to inappropriate sampling rates extracted from the literature and for our system, and new values are proposed. Considering the all data set, 75% of the results indicate a relatively good agreement between the POCIS and the average water samples concentration (values of the ratio ranging between 0,33 and 3). Note further that this agreement between these concentrations remains valid considering different sampling rates extracted from the literature. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of sampling inhalable PM10 particulate matter (≤ 10 μm) using co-located high volume samplers

International Nuclear Information System (INIS)

Rajoy, R R S; Dias, J W C; Rego, E C P; Netto, A D Pereira

2015-01-01

This paper presents the results of the determination of the concentrations of atmospheric particulate matter ≤ 10 μm (PM10), collected simultaneously by six PM10 high volume samplers from two different manufacturers installed in the same location. Fifteen samples of 24 h were obtained with each equipment at a selected urban area of Rio de Janeiro city. The concentration of PM10 ranged between 10.73 and 54.04 μg m −3 . The samplers were considered comparable to each other, as the adopted methodology presented good repeatability

Russian upstream joint ventures logging progress

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that Occidental Petroleum Corp. has begun exporting oil from Russia as part of an enhanced recovery joint venture in western Siberia. Oxy holds a 50% interest in the joint venture company, Vanyoganneft, and will market the oil. In other activity, two Canadian companies are marking progress with Russian upstream joint ventures

A New Time Calibration Method for Switched-capacitor-array-based Waveform Samplers.

Science.gov (United States)

Kim, H; Chen, C-T; Eclov, N; Ronzhin, A; Murat, P; Ramberg, E; Los, S; Moses, W; Choong, W-S; Kao, C-M

2014-12-11

We have developed a new time calibration method for the DRS4 waveform sampler that enables us to precisely measure the non-uniform sampling interval inherent in the switched-capacitor cells of the DRS4. The method uses the proportionality between the differential amplitude and sampling interval of adjacent switched-capacitor cells responding to a sawtooth-shape pulse. In the experiment, a sawtooth-shape pulse with a 40 ns period generated by a Tektronix AWG7102 is fed to a DRS4 evaluation board for calibrating the sampling intervals of all 1024 cells individually. The electronic time resolution of the DRS4 evaluation board with the new time calibration is measured to be ~2.4 ps RMS by using two simultaneous Gaussian pulses with 2.35 ns full-width at half-maximum and applying a Gaussian fit. The time resolution dependencies on the time difference with the new time calibration are measured and compared to results obtained by another method. The new method could be applicable for other switched-capacitor-array technology-based waveform samplers for precise time calibration.

FAST MUSIC SPECTRUM PEAK SEARCH VIA METROPOLIS-HASTINGS SAMPLER

Institute of Scientific and Technical Information of China (English)

Guo Qinghua; Liao Guisheng

2005-01-01

A fast MUltiple SIgnal Classification (MUSIC) spectrum peak search algorithm is devised, which regards the power of the MUSIC spectrum function as target distribution up to a constant of proportionality, and uses Metropolis-Hastings (MH) sampler, one of the most popular Markov Chain Monte Carlo (MCMC) techniques, to sample from it. The proposed method reduces greatly the tremendous computation and storage costs in conventional MUSIC techniques i.e., about two and four orders of magnitude in computation and storage costs under the conditions of the experiment in the paper respectively.

Comparison of atmospheric concentrations of currently used pesticides between urban and rural areas during intensive application period in Alsace (France) by using XAD-2® based passive samplers.

Science.gov (United States)

Liaud, Celine; Schwartz, Jean-Jacques; Millet, Maurice

2017-07-03

XAD-2® passive samplers (PAS) have been exposed simultaneously for 14 days on two sites, one rural and one urban, situated in Alsace (East of France) during intensive pesticides application in agriculture (between March and September). PAS have been extracted and analyzed for current-used pesticides and lindane with an analytical method coupling accelerated solvent extraction (ASE), solid-phase microextraction (SPME) and GC/MS/MS. Results show the detection of pesticides is linked to the period of application and spatial and temporal variabilities can be observed with these PAS during the selected sampling period. The spatial and temporal variability is comparable to the one previously observed by comparing data obtained with PAS with data from Hi.-Vol. samplers in an urban area. Sampling rates were calculated for some pesticides and values are comparable to the data already available in the literature. From these sampling rates, concentrations in ng m -3 of pesticides in PAS have been calculated and are in the same order of magnitude as those obtained with Hi.Vol. sampling during the same period of time.

Performance of an air sampler and a gamma-ray detector in a small unmanned aerial vehicle

International Nuclear Information System (INIS)

Roy Poellaenen; Harri Toivonen; Kari Peraejaervi; Tero Karhunen; Petri Smolander; Tarja Ilander; Kimmo Rintala; Tuure Katajainen; Jarkko Niemelae; Marko Juusela; Timo Palos

2009-01-01

The performance of an air sampler and a small gamma-ray spectrometer was tested in an unmanned aerial vehicle (UAV) able to carry payload with mass up to 0.5 kg. Operation of the sampler was investigated with the aid of radon progeny normally present in outdoor air. Detection limits for several transuranium nuclides in air are of the order of 0.3 Bq m -3 assuming 0.5 h sampling time and 1 h counting time in direct alpha spectrometry. Unshielded 137 Cs and 60 Co point sources at the ground level were used to test the CsI spectrometer. Detection limits are approximately 1 GBq or larger depending on the flying altitude. (author)

Characterization of Rous sarcoma virus polyadenylation site use in vitro

International Nuclear Information System (INIS)

Maciolek, Nicole L.; McNally, Mark T.

2008-01-01

Polyadenylation of Rous sarcoma virus (RSV) RNA is inefficient, as approximately 15% of RSV RNAs represent read-through transcripts that use a downstream cellular polyadenylation site (poly(A) site). Read-through transcription has implications for the virus and the host since it is associated with oncogene capture and tumor induction. To explore the basis of inefficient RSV RNA 3'-end formation, we characterized RSV polyadenylation in vitro using HeLa cell nuclear extracts and HEK293 whole cell extracts. RSV polyadenylation substrates composed of the natural 3' end of viral RNA and various lengths of upstream sequence showed little or no polyadenylation, indicating that the RSV poly(A) site is suboptimal. Efficiently used poly(A) sites often have identifiable upstream and downstream elements (USEs and DSEs) in close proximity to the conserved AAUAAA signal. The sequences upstream and downstream of the RSV poly(A) site deviate from those found in efficiently used poly(A) sites, which may explain inefficient RSV polyadenylation. To assess the quality of the RSV USEs and DSEs, the well-characterized SV40 late USEs and/or DSEs were substituted for the RSV elements and vice versa, which showed that the USEs and DSEs from RSV are suboptimal but functional. CstF interacted poorly with the RSV polyadenylation substrate, and the inactivity of the RSV poly(A) site was at least in part due to poor CstF binding since tethering CstF to the RSV substrate activated polyadenylation. Our data are consistent with poor polyadenylation factor binding sites in both the USE and DSE as the basis for inefficient use of the RSV poly(A) site and point to the importance of additional elements within RSV RNA in promoting 3' end formation

Side-by-side determination of workers' exposure to wood dust with IOM and open-faced samplers.

Science.gov (United States)

Cavlović, Anka Ozana; Beljo Lučić, Ružica; Jug, Matija; Radmanović, Kristijan; Bešlić, Ivan

2013-09-01

Woodworkers' exposure to airborne particles is measured with different sampling techniques throughout the world. Due to a great number of exposure data obtained with different samplers, European countries have aimed over the last ten years to find a conversion factor for mass concentrations that would render these measurements comparable. Following the accepted EU standards and regulations, we replaced a 25 mm open-faced (OF) filter holder with an IOM head to determine woodworkers' exposure to inhalable dust and establish an IOM/OF sampler ratio that might serve as a reliable factor for converting the existing OF data to IOM dust mass concentration in the industrial environment. For this side-by-side sampling we used personal 25 mm OF (N=29) and IOM (N=29) sampling heads over eight working hours. The obtained IOM/OF ratios ranged between 0.7 and 2.3. However, mass concentrations obtained by IOM and OF samplers did not significantly differ. Our findings suggest that there is no need for conversion of the existing OF data for workers exposed to wood dust, provided that dust mass concentrations in the working environment range between 1 mg m-3 and 7 mg m-3. Future side-by-side measurements should also involve environments with low wood dust mass concentrations.

Comparison of marine sampling methods for organic contaminants: Passive samplers, water extractions, and live oyster deployment.

Science.gov (United States)

Raub, Kristin B; Vlahos, Penny; Whitney, Michael

2015-08-01

Laboratory and field trials evaluated the efficacy of three methods of detecting aquatic pesticide concentrations. Currently used pesticides: atrazine, metolachlor, and diazinon and legacy pesticide dieldrin were targeted. Pesticides were extracted using solid-phase extraction (SPE) of water samples, titanium plate passive samplers coated in ethylene vinyl acetate (EVA) and eastern oysters (Crassostrea viginica) as biosamplers. A laboratory study assessed the extraction efficiencies and precision of each method. Passive samplers yielded the highest precision of the three methods (RSD: 3-14% EVA plates; 19-60% oysters; and 25-56% water samples). Equilibrium partition coefficients were derived. A significant relationship was found between the concentration in oyster tissue and the ambient aquatic concentration. In the field (Housatonic River, CT (U.S.)) water sampling (n = 5) detected atrazine at 1.61-7.31 μg L(-1), oyster sampling (n = 2×15) detected dieldrin at n.d.-0.096 μg L(-1) SW and the passive samplers (n = 5×3) detected atrazine at 0.97-3.78 μg L(-1) SW and dieldrin at n.d.-0.68 μg L(-1) SW. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification of putative regulatory motifs in the upstream regions of co-expressed functional groups of genes in Plasmodium falciparum

Directory of Open Access Journals (Sweden)

Joshi NV

2009-01-01

Full Text Available Abstract Background Regulation of gene expression in Plasmodium falciparum (Pf remains poorly understood. While over half the genes are estimated to be regulated at the transcriptional level, few regulatory motifs and transcription regulators have been found. Results The study seeks to identify putative regulatory motifs in the upstream regions of 13 functional groups of genes expressed in the intraerythrocytic developmental cycle of Pf. Three motif-discovery programs were used for the purpose, and motifs were searched for only on the gene coding strand. Four motifs – the 'G-rich', the 'C-rich', the 'TGTG' and the 'CACA' motifs – were identified, and zero to all four of these occur in the 13 sets of upstream regions. The 'CACA motif' was absent in functional groups expressed during the ring to early trophozoite transition. For functional groups expressed in each transition, the motifs tended to be similar. Upstream motifs in some functional groups showed 'positional conservation' by occurring at similar positions relative to the translational start site (TLS; this increases their significance as regulatory motifs. In the ribonucleotide synthesis, mitochondrial, proteasome and organellar translation machinery genes, G-rich, C-rich, CACA and TGTG motifs, respectively, occur with striking positional conservation. In the organellar translation machinery group, G-rich motifs occur close to the TLS. The same motifs were sometimes identified for multiple functional groups; differences in location and abundance of the motifs appear to ensure different modes of action. Conclusion The identification of positionally conserved over-represented upstream motifs throws light on putative regulatory elements for transcription in Pf.

On-line soft sensing in upstream bioprocessing.

Science.gov (United States)

Randek, Judit; Mandenius, Carl-Fredrik

2018-02-01

This review provides an overview and a critical discussion of novel possibilities of applying soft sensors for on-line monitoring and control of industrial bioprocesses. Focus is on bio-product formation in the upstream process but also the integration with other parts of the process is addressed. The term soft sensor is used for the combination of analytical hardware data (from sensors, analytical devices, instruments and actuators) with mathematical models that create new real-time information about the process. In particular, the review assesses these possibilities from an industrial perspective, including sensor performance, information value and production economy. The capabilities of existing analytical on-line techniques are scrutinized in view of their usefulness in soft sensor setups and in relation to typical needs in bioprocessing in general. The review concludes with specific recommendations for further development of soft sensors for the monitoring and control of upstream bioprocessing.

Development of an integrated sampler based on direct 222Rn/220Rn progeny sensors in flow-mode for estimating unattached/attached progeny concentration

International Nuclear Information System (INIS)

Mishra, Rosaline; Sapra, B.K.; Mayya, Y.S.

2009-01-01

A flow-mode integrated sampler consisting of a wire-mesh and filter-paper array along with passive solid state nuclear track detectors has been developed for estimating unattached and attached fraction of 222 Rn/ 220 Rn progeny concentration. The essential element of this sampler is the direct 222 Rn/ 220 Rn progeny sensor (DRPS/DTPS), which is an absorber-mounted-LR115 type nuclear track detector that selectively registers the alpha particles emitted from the progeny deposited on its surface. During sampling at a specified flow-rate, the unattached progeny is captured on the wire-mesh; while the attached progeny gets transmitted and is captured on the filter-paper. The alpha particles emitted by the deposited progeny atoms are registered on the sensors placed at a specified distance facing the wire-mesh and the filter-paper, respectively. The various steps involved in the development of this flow-mode direct progeny sampler such as the optimization of the sampling rate and the distance between the sensor and the deposition substrate are discussed. The sensitivity factor of the DTPS-loaded sampler for 220 Rn progeny deposited on the wire-mesh and filter-paper is found to be 23.77 ± 0.64 (track cm -2 h -1 ) (Bq m -3 ) -1 and 22.30 ± 0.18 (track cm -2 h -1 ) (Bq m -3 ) -1 , respectively; while that of DRPS-loaded sampler for 222 Rn progeny deposition, is 3.03 ± 0.14 (track cm -2 h -1 ) (Bq m -3 ) -1 and 2.08 ± 0.07 (track cm -2 h -1 ) (Bq m -3 ) -1 , respectively. The highlight of this flow-mode sampler is its high sensitivity and that it utilizes the passive technique for estimating the unattached and attached progeny concentration, thus doing away with the alpha counting procedures.

A population-based exposure assessment methodology for carbon monoxide: Development of a carbon monoxide passive sampler and occupational dosimeter

Energy Technology Data Exchange (ETDEWEB)

Apte, Michael G. [Univ. of California, Berkeley, CA (United States)

1997-09-01

Two devices, an occupational carbon monoxide (CO) dosimeter (LOCD), and an indoor air quality (IAQ) passive sampler were developed for use in population-based CO exposure assessment studies. CO exposure is a serious public health problem in the U.S., causing both morbidity and mortality (lifetime mortality risk approximately 10{sup -4}). Sparse data from population-based CO exposure assessments indicate that approximately 10% of the U.S. population is exposed to CO above the national ambient air quality standard. No CO exposure measurement technology is presently available for affordable population-based CO exposure assessment studies. The LOCD and IAQ Passive Sampler were tested in the laboratory and field. The palladium-molybdenum based CO sensor was designed into a compact diffusion tube sampler that can be worn. Time-weighted-average (TWA) CO exposure of the device is quantified by a simple spectrophotometric measurement. The LOCD and IAQ Passive Sampler were tested over an exposure range of 40 to 700 ppm-hours and 200 to 4200 ppm-hours, respectively. Both devices were capable of measuring precisely (relative standard deviation <20%), with low bias (<10%). The LOCD was screened for interferences by temperature, humidity, and organic and inorganic gases. Temperature effects were small in the range of 10°C to 30°C. Humidity effects were low between 20% and 90% RH. Ethylene (200 ppm) caused a positive interference and nitric oxide (50 ppm) caused a negative response without the presence of CO but not with CO.

Determining the spatial variability of personal sampler inlet locations.

Science.gov (United States)

Vinson, Robert; Volkwein, Jon; McWilliams, Linda

2007-09-01

This article examines the spatial variability of dust concentrations within a coal miner's breathing zone and the impact of sampling location at the cap lamp, nose, and lapel. Tests were conducted in the National Institute for Safety and Health Pittsburgh Research Laboratory full-scale, continuous miner gallery using three prototype personal dust monitors (PDM). The dust masses detected by the PDMs were used to calculate the percentage difference of dust mass between the cap lamp and the nose and between the lapel and the nose. The calculated percentage differences of the masses ranged from plus 12% to minus 25%. Breathing zone tests were also conducted in four underground coal mines using the torso of a mannequin to simulate a miner. Coal mine dust was sampled with multi-cyclone sampling cans mounted directly in front of the mannequin near the cap lamp, nose, and lapel. These four coal mine tests found that the spatial variability of dust levels and imprecision of the current personal sampler is a greater influence than the sampler location within the breathing zone. However, a one-sample t-test of this data did find that the overall mean value of the cap lamp/nose ratio was not significantly different than 1 (p-value = 0.21). However, when applied to the overall mean value of the lapel/nose ratio there was a significant difference from 1 (p-value sampling location for coal mine dust samples. But these results suggest that the cap location is slightly more indicative of what is breathed through the nose area.

Upstream structural management measures for an urban area flooding in Turkey

Science.gov (United States)

Akyurek, Z.; Bozoğlu, B.; Sürer, S.; Mumcu, H.

2015-06-01

In recent years, flooding has become an increasing concern across many parts of the world of both the general public and their governments. The climate change inducing more intense rainfall events occurring in short period of time lead flooding in rural and urban areas. In this study the flood modelling in an urbanized area, namely Samsun-Terme in Blacksea region of Turkey is performed. MIKE21 with flexible grid is used in 2-dimensional shallow water flow modelling. 1 × 1000-1 scaled maps with the buildings for the urbanized area and 1 × 5000-1 scaled maps for the rural parts are used to obtain DTM needed in the flood modelling. The bathymetry of the river is obtained from additional surveys. The main river passing through the urbanized area has a capacity of 500 m3 s-1 according to the design discharge obtained by simple ungauged discharge estimation depending on catchment area only. The upstream structural base precautions against flooding are modelled. The effect of four main upstream catchments on the flooding in the downstream urban area are modelled as different scenarios. It is observed that if the flow from the upstream catchments can be retarded through a detention pond constructed in one of the upstream catchments, estimated Q100 flood can be conveyed by the river without overtopping from the river channel. The operation of the upstream detention ponds and the scenarios to convey Q500 without causing flooding are also presented. Structural management measures to address changes in flood characteristics in water management planning are discussed.

DENSITY FLUCTUATIONS UPSTREAM AND DOWNSTREAM OF INTERPLANETARY SHOCKS

Energy Technology Data Exchange (ETDEWEB)

Pitňa, A.; Šafránková, J.; Němeček, Z.; Goncharov, O.; Němec, F.; Přech, L. [Charles University, Faculty of Mathematics and Physics, V Holešovičkách 2, 180 00 Prague 8 (Czech Republic); Chen, C. H. K. [Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom); Zastenker, G. N., E-mail: jana.safrankova@mff.cuni.cz [Space Research Institute of Russian Academy of Sciences, Moscow, Russia, Profsoyuznaya ul. 84/32, Moscow 117997 (Russian Federation)

2016-03-01

Interplanetary (IP) shocks as typical large-scale disturbances arising from processes such as stream–stream interactions or Interplanetary Coronal Mass Ejection (ICME) launching play a significant role in the energy redistribution, dissipation, particle heating, acceleration, etc. They can change the properties of the turbulent cascade on shorter scales. We focus on changes of the level and spectral properties of ion flux fluctuations upstream and downstream of fast forward oblique shocks. Although the fluctuation level increases by an order of magnitude across the shock, the spectral slope in the magnetohydrodynamic range is conserved. The frequency spectra upstream of IP shocks are the same as those in the solar wind (if not spoiled by foreshock waves). The spectral slopes downstream are roughly proportional to the corresponding slopes upstream, suggesting that the properties of the turbulent cascade are conserved across the shock; thus, the shock does not destroy the shape of the spectrum as turbulence passes through it. Frequency spectra downstream of IP shocks often exhibit “an exponential decay” in the ion kinetic range that was earlier reported at electron scales in the solar wind or at ion scales in the interstellar medium. We suggest that the exponential shape of ion flux spectra in this range is caused by stronger damping of the fluctuations in the downstream region.

Two-Stage Variable Sample-Rate Conversion System

Science.gov (United States)

Tkacenko, Andre

2009-01-01

A two-stage variable sample-rate conversion (SRC) system has been pro posed as part of a digital signal-processing system in a digital com munication radio receiver that utilizes a variety of data rates. The proposed system would be used as an interface between (1) an analog- todigital converter used in the front end of the receiver to sample an intermediatefrequency signal at a fixed input rate and (2) digita lly implemented tracking loops in subsequent stages that operate at v arious sample rates that are generally lower than the input sample r ate. This Two-Stage System would be capable of converting from an input sample rate to a desired lower output sample rate that could be var iable and not necessarily a rational fraction of the input rate.

Soil separator and sampler and method of sampling

Science.gov (United States)

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

2010-02-16

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

Exploring Social Learning through Upstream Engagement in Science and Technology

DEFF Research Database (Denmark)

Mortensen, Jonas Egmose

This discussion paper deliberates on how the concept of social learning can be used for evaluating upstream engagement initiatives in science and technology.  The paper briefly introduces to the concept of upstream engagement and a concrete case, the UK Citizen Science for Sustainability project...... (SuScit), as an outset for discussing how the concept of social learning can be used for analysing and understanding relations between citizen participation, Science and research, and sustainability. A number of relevant research questions and methodological considerations are distilled...

Monitoring upstream sinkhole development by detailed sonar profiling

Energy Technology Data Exchange (ETDEWEB)

Rigbey, S. [Acres International Ltd., Niagara Falls, ON (Canada)

2004-09-01

This paper describes the development and use of a simple sonar system that has been used by engineers for routine monitoring of small sinkholes on the upstream face of a distressed earth dam. Improper construction of the dam led to the development of several sinkholes measuring 10 to 20 m in diameter upstream from the dam which is founded on deep alluvial sands and gravels. The dam has a central core of silt and leakage varies between 200 and 500 l/s, depending on the water level of the reservoir. The main issues with the upstream blanket are: improper fill placement due to the inability to dewater the area properly; omission of a filter material between the blanket and the alluvium foundation; thin placement of fill and runnelling of the blanket prior to impoundment; and, short upstream extent of the blanket. A downstream weighting toe of material was placed to address the seepage and piping that developed immediately following impounding. Other incidents continued over the years, such as downstream sinkholes, slumping of the crest and repairs about 12 years after construction. An inverter filter was also constructed to better control the seepage. Simple bathymetric surveys conducted by sounding the bottom of the reservoir from the ice surface each winter revealed the presence of several large sinkholes. Although infilling programs were conducted, sinkholes redeveloped after each program. The bathymetric surveys were found to be limited in accuracy and repeatability. Therefore, it was not possible to monitor small developments on a yearly basis. A 3-dimensional seepage model was developed to reconcile some of the unexplained piezometric patterns and to better understand the seepage patterns. However, this was also unsuccessful on its own. A trial sonar survey was then undertaken in 2002 by a Vancouver-based sonar company using an Imagenix profiling sonar head. It was successful in locating a small, previously unknown sinkhole measuring a few metres in diameter at

Upstream oil and gas. Subsector no. 7: Oil and gas exploration and development 1995 to 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-08-01

Prepared by the Alberta Human Resources and Employment, this report provides a summary of the lost-time injuries and disease descriptions of workers injured while employed in the upstream oil and gas industries in Alberta during the period 1995 to 1999. The report includes the characteristics of the injured worker and the risk of injury to workers in the industries in Alberta, as well as the cost of injuries and revenue by means of total premiums paid by the employers. The occupational fatalities that were accepted by the Workers Compensation Board and investigated by the Occupational Health and Safety were summarized in the report along with a brief description of the injuries. The aim was to provide information concerning health and safety issues to government, employers, workers, and health and safety officers in the industries in Alberta about health and safety issues. The focus was placed on the oil and gas exploration and development sub-sector. Defined as all upstream oil field activities of employers which generate revenue from the production and sale of crude oil and/or natural gas, the sub-sector comprises major integrated oil and gas companies and small independent producers. In those cases where the owner/producer operates its own upstream production/processing facilities, they form an integral part of this sub-section. In addition, oil and gas marketing firms are included. Oil/gas well, well head equipment; flow lines/gathering systems tied into field processing facilities; battery sites/compressors stations; crude oil separators and natural gas dehydrators/treaters; natural gas/sulfur processing plants; heavy oil projects including steam generation; and other enhanced recovery methods are all included in the sub-sector. The other sub-sectors in the upstream oil and gas industries are: exploration, oilfield maintenance and construction, well servicing with service rigs and power swivels, drilling of oil and gas wells, oilfield downhole and other

Survey of Potential Hanford Site Contaminants in the Upper Sediment for the Reservoirs at McNary, John Day, The Dalles, and Bonneville Dams, 2003

Energy Technology Data Exchange (ETDEWEB)

Patton, Gregory W.; Priddy, M; Yokel, Jerel W.; Delistraty, Damon A.; Stoops, Thomas M.

2005-02-01

This report presents the results from a multi-agency cooperative environmental surveillance study. of the study looked at sediment from the pools upstream from dams on the Columbia River that are downstream from Hanford Site operations. The radiological and chemical conditions existing in the upper-level sediment found in the pools upstream from McNary Dam, John Day Dam, The Dalles Lock and Dam, and Bonneville Dam were evaluated. This study also evaluated beach sediment where available. Water samples were collected at McNary Dam to further evaluate potential Hanford contaminants in the lower Columbia River. Samples were analyzed for radionuclides, chemicals, and physical parameters. Results from this study were compared to background values from sediment and water samples collect from the pool upstream of Priest Rapids Dam (upstream of the Hanford Site) by the Hanford Site Surface Environmental Surveillance Project.

astroABC : An Approximate Bayesian Computation Sequential Monte Carlo sampler for cosmological parameter estimation

Energy Technology Data Exchange (ETDEWEB)

Jennings, E.; Madigan, M.

2017-04-01

Given the complexity of modern cosmological parameter inference where we arefaced with non-Gaussian data and noise, correlated systematics and multi-probecorrelated data sets, the Approximate Bayesian Computation (ABC) method is apromising alternative to traditional Markov Chain Monte Carlo approaches in thecase where the Likelihood is intractable or unknown. The ABC method is called"Likelihood free" as it avoids explicit evaluation of the Likelihood by using aforward model simulation of the data which can include systematics. Weintroduce astroABC, an open source ABC Sequential Monte Carlo (SMC) sampler forparameter estimation. A key challenge in astrophysics is the efficient use oflarge multi-probe datasets to constrain high dimensional, possibly correlatedparameter spaces. With this in mind astroABC allows for massive parallelizationusing MPI, a framework that handles spawning of jobs across multiple nodes. Akey new feature of astroABC is the ability to create MPI groups with differentcommunicators, one for the sampler and several others for the forward modelsimulation, which speeds up sampling time considerably. For smaller jobs thePython multiprocessing option is also available. Other key features include: aSequential Monte Carlo sampler, a method for iteratively adapting tolerancelevels, local covariance estimate using scikit-learn's KDTree, modules forspecifying optimal covariance matrix for a component-wise or multivariatenormal perturbation kernel, output and restart files are backed up everyiteration, user defined metric and simulation methods, a module for specifyingheterogeneous parameter priors including non-standard prior PDFs, a module forspecifying a constant, linear, log or exponential tolerance level,well-documented examples and sample scripts. This code is hosted online athttps://github.com/EliseJ/astroABC

PCDD, PCDF, dl-PCB and organochlorine pesticides monitoring in São Paulo City using passive air sampler as part of the Global Monitoring Plan.

Science.gov (United States)

Tominaga, M Y; Silva, C R; Melo, J P; Niwa, N A; Plascak, D; Souza, C A M; Sato, M I Z

2016-11-15

The persistent organic pollutants (POPs), such as organochlorine pesticides and PCBs, are ordinarily monitored in the aquatic environment or in soil in the environmental quality monitoring programs in São Paulo, Brazil. One of the core matrices proposed in the POPs Global Monitoring Plan (GMP) from the Stockholm Convention list is the ambient air, which is not a usual matrix for POPs monitoring in the country. In this study POP levels were evaluated in the air samples from an urban site in São Paulo City over five years, starting in 2010 as a capacity building project for Latin America and the Caribbean region for POP monitoring in ambient air using passive samplers. Furthermore, after the end of the Project in 2012, the monitoring continued in the same sampling site as means to improving the analytical capacity building and contribute to the GMP data. The POPs monitored were 17 congeners of 2,3,7,8 chloro-substituted PCDDs and PCDFs, dioxin-like PCBs, indicator PCBs, organochlorine pesticides and toxaphene. The results show a slight decrease in PCDD/F, dl-PCBs and indicator PCBs levels along the five years. The organochlorine pesticide endosulfan was present at its highest concentration at the beginning of the monitoring period, but it was below detection level in the last year of the monitoring. Some other organochlorine pesticides were detected close to or below quantitation limits. The compounds identified were dieldrin, chlordane, α-HCH, γ-HCH, heptachlor, heptachlor epoxide, hexachlorobenzene and DDTs. Toxaphene congeners were not detected. These results have confirmed the efficacy of passive sampling for POP monitoring and the capacity building for POP analysis and monitoring was established. However more needs to be done, including expansion of sampling sites, new POPs and studies on sampling rates to be considered in calculating the concentration of POPs in ambient air using a passive sampler. Copyright © 2016 Elsevier B.V. All rights reserved.

User's guide for polyethylene-based passive diffusion bag samplers to obtain volatile organic compound concentrations in wells. Part I, Deployment, recovery, data interpretation, and quality control and assurance

Science.gov (United States)

Vroblesky, Don A.

2001-01-01

Diffusion samplers installed in observation wells were found to be capable of yielding representative water samples for chlorinated volatile organic compounds. The samplers consisted of polyethylene bags containing deionized water and relied on diffusion of chlorinated volatile organic compounds through the polyethylene membrane. The known ability of polyethylene to transmit other volatile compounds, such as benzene and toluene, indicates that the samplers can be used for a variety of volatile organic compounds. In wells at the study area, the volatile organic compound concentrations in water samples obtained using the samplers without prior purging were similar to concentrations in water samples obtained from the respective wells using traditional purging and sampling approaches. The low cost associated with this approach makes it a viable option for monitoring large observation-well networks for volatile organic compounds.

Field test of the PNNL Automated Radioxenon Sampler/Analyzer (ARSA)

International Nuclear Information System (INIS)

Lagomarsino, R.J.; Ku, E.; Latner, N.; Sanderson, C.G.

1998-07-01

As part of the requirements of the Comprehensive Test Ban Treaty (CTBT), the Automated Radioxenon/Sampler Analyzer (ARSA) was designed and engineered by the Pacific Northwest National Laboratory (PNNL). The instrument is to provide near real-time detection and measurement of the radioxenons released into the atmosphere after a nuclear test. Forty-six field tests, designed to determine the performance of the ARSA prototype under simulated field conditions, were conducted at EML from March to December 1997. This final report contains detailed results of the tests with recommendations for improvements in instrument performance

Field test of the PNNL Automated Radioxenon Sampler/Analyzer (ARSA)

Energy Technology Data Exchange (ETDEWEB)

Lagomarsino, R.J.; Ku, E.; Latner, N.; Sanderson, C.G.

1998-07-01

As part of the requirements of the Comprehensive Test Ban Treaty (CTBT), the Automated Radioxenon/Sampler Analyzer (ARSA) was designed and engineered by the Pacific Northwest National Laboratory (PNNL). The instrument is to provide near real-time detection and measurement of the radioxenons released into the atmosphere after a nuclear test. Forty-six field tests, designed to determine the performance of the ARSA prototype under simulated field conditions, were conducted at EML from March to December 1997. This final report contains detailed results of the tests with recommendations for improvements in instrument performance.

Moving Upstream in U.S. Hospital Care Toward Investments in Population Health.

Science.gov (United States)

Begun, James W; Potthoff, Sandra

The root causes for most health outcomes are often collectively referred to as the social determinants of health. Hospitals and health systems now must decide how much to "move upstream," or invest in programs that directly affect the social determinants of health. Moving upstream in healthcare delivery requires an acceptance of responsibility for the health of populations. We examine responses of 950 nonfederal, general hospitals in the United States to the 2015 American Hospital Association Population Health Survey to identify characteristics that distinguish those hospitals that are most aligned with population health and most engaged in addressing social determinants of health. Those "upstream" hospitals are significantly more likely to be large, not-for-profit, metropolitan, teaching-affiliated, and members of systems. Internally, the more upstream hospitals are more likely to organize their population health activities with strong executive-level involvement, full-time-equivalent support, and coordination at the system level.The characteristics differentiating hospitals strongly involved in population health and upstream activity are not unlike those characteristics associated with diffusion of many innovations in hospitals. These hospitals may be the early adopters in a diffusion process that will eventually include most hospitals or, at least, most not-for-profit hospitals. Alternatively, the population health and social determinants movements could be transient or could be limited to a small portion of hospitals such as those identified here, with distinctive patient populations, missions, and resources.

The glnAntrBC operon of Herbaspirillum seropedicae is transcribed by two oppositely regulated promoters upstream of glnA.

Science.gov (United States)

Schwab, Stefan; Souza, Emanuel M; Yates, Marshall G; Persuhn, Darlene C; Steffens, M Berenice R; Chubatsu, Leda S; Pedrosa, Fábio O; Rigo, Liu U

2007-01-01

Herbaspirillum seropedicae is an endophytic bacterium that fixes nitrogen under microaerophilic conditions. The putative promoter sequences glnAp1 (sigma70-dependent) and glnAp2 (sigma54), and two NtrC-binding sites were identified upstream from the glnA, ntrB and ntrC genes of this microorganism. To study their transcriptional regulation, we used lacZ fusions to the H. seropedicae glnA gene, and the glnA-ntrB and ntrB-ntrC intergenic regions. Expression of glnA was up-regulated under low ammonium, but no transcription activity was detected from the intergenic regions under any condition tested, suggesting that glnA, ntrB and ntrC are co-transcribed from the promoters upstream of glnA. Ammonium regulation was lost in the ntrC mutant strain. A point mutation was introduced in the conserved -25/-24 dinucleotide (GG-->TT) of the putative sigma54-dependent promoter (glnAp2). Contrary to the wild-type promoter, glnA expression with the mutant glnAp2 promoter was repressed in the wild-type strain under low ammonium levels, but this repression was abolished in an ntrC background. Together our results indicate that the H. seropedicae glnAntrBC operon is regulated from two functional promoters upstream from glnA, which are oppositely regulated by the NtrC protein.

Development and evaluation of an impactor sampler for radioactive aerosol particles

International Nuclear Information System (INIS)

Sorimachi, Atsuyuki; Kranrod, Chutima; Chantrarayotha, Supitcha; Tokonami, Shinji

2008-01-01

This sampler consists of one impaction stage, which allows separation of airborne particles by 1 μm particle size cut-off point with a 50% probability of impaction, followed by a back-up filter at a flow rate of 1 L min -1 . The particles size more than and less than 1 μm-diameter are collected on the impactor plate at the nozzle side and on the filter, respectively. A Cr-39 detector is mounted on the filter sides of the impaction plate; α particles emitted from the particles less than 1 μm-diameter are counted with the Cr-39 detectors. In order to separate α particles emitted from radon, thoron and their progeny, the Cr-39 detectors are covered with aluminum-vaporized Mylar films. The total thickness of films is adjusted to let their α particles impinge on the Cr-39 detectors. Laboratory tests are going on in terms of the spectral characteristics of α particles before and after passing through the films, the count rate performance of Cr-39 detectors by α particles, the actual collection efficiency of aerosol particles on the impaction plate, and so on. This sampler may be able to supply us with an interesting technique for measuring radon and thoron progeny come from the sources of natural radiation such as the naturally occurred radioactive materials. (author)

Optical power equalization for upstream traffic with injection-locked Fabry-Perot lasers in TDM-PON

Science.gov (United States)

Huang, Ting-Tsan; Sheu, Lih-Gen; Chi, Sien

2010-10-01

An optical power equalization of upstream traffic in time-division-multiplexed passive optical network (TDM-PON) based on injection-locked Fabry-Perot lasers has been experimentally investigated. The upstream transmitters with stable spectrum are achieved by using an external injection light source in the optical line terminal (OLT). The different upstream powers can be equalized by injection locking a Fabry-Perot laser diode (FP-LD) biased below threshold current in OLT. The dynamic upstream power range from - 8.5 to - 19.5 db m is reduced to a 1.6 dB maximal power variation, when the uplink signal is directly modulated at 1.25 Gb/s.

Anatomy of top 100 upstream players

International Nuclear Information System (INIS)

Burk, V.A.

1992-01-01

A brief review is given of a recent survey of the top one hundred upstream oil and gas companies which file financial data with the US Securities and Exchange Commission. The analysis indicates the increasing globalisation of the industry with exploration and development spending increasing dramatically outside the US. To survive, companies must operate as efficient low cost finders and producers of oil and gas and anticipate and meet changing market demands quickly. (UK)

Air Pollutant Emissions from Oil and Gas Production pads (Investigating Low Cost Passive Samplers)

Science.gov (United States)

To help achieve the goal of sustainable, environmentally responsible development of oil and gas resources, it isnecessary to understand the potential for air pollutant emissions from various extraction and production (E&P)processes at the upstream, wellpad level. Upstream oil and...

Study on air pollution monitoring in Korea using low volume air sampler by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Yong Sam Chung; Jong Hwa Moon, Young Ju Chung; Seung Yeon Cho; Sang Hun Kang

1999-01-01

The aim of this research was to enhance the use of nuclear analytical techniques for air pollution studies and to study the feasibility of the use of instrumental neutron activation analysis (INAA) as a routine monitoring tool to reveal environmental pollution sources. For the collection of air particulate samples, the Gent stacked filter unit, low volume sampler with Nucleopore membrane filters were used. Trace elements in samples collected at two suburban residential sites, Taejon and Wonju city in the Republic of Korea, were analyzed by INAA. Variations of the elemental concentrations were measured monthly and the enrichment factors were calculated for the fine (< 2 μm EAD) and coarse size (2-10 μm EAD) fractions. The analytical data were treated statistically to estimate the relationship between the two variables, the concentrations of elements and the total suspended particulate matter. The results were used to describe the emission source and their correlation. (author)

Guidelines for the use of the semipermeable membrane device (SPMD) and the polar organic chemical integrative sampler (POCIS) in environmental monitoring studies

Science.gov (United States)

Alvarez, David A.

2010-01-01

The success of an environmental monitoring study using passive samplers, or any sampling method, begins in the office or laboratory. Regardless of the specific methods used, the general steps include the formulation of a sampling plan, training of personnel, performing the field (sampling) work, processing the collected samples to recover chemicals of interest, analysis of the enriched extracts, and interpretation of the data. Each of these areas will be discussed in the following sections with emphasis on specific considerations with the use of passive samplers. Water is an extremely heterogeneous matrix both spatially and temporally (Keith, 1991). The mixing and distribution of dissolved organic chemicals in a water body are controlled by the hydrodynamics of the water, the sorption partition coefficients of the chemicals, and the amount of organic matter (suspended sediments, colloids, and dissolved organic carbon) present. In lakes and oceans, stratification because of changes in temperature, water movement, and water composition can occur resulting in dramatic changes in chemical concentrations with depth (Keith, 1991). Additional complications related to episodic events, such as surface runoff, spills, and other point source contamination, can result in isolated or short-lived pulses of contaminants in the water. The application of passive sampling technologies for the monitoring of legacy and emerging organic chemicals in the environment is becoming widely accepted worldwide. The primary use of passive sampling methods for environmental studies is in the area of surface-water monitoring; however, these techniques have been applied to air and groundwater monitoring studies. Although these samplers have no mechanical or moving parts, electrical or fuel needs which require regular monitoring, there are still considerations that need to be understood in order to have a successful study. Two of the most commonly used passive samplers for organic contaminants are

Multiple upstream modules regulate zebrafish myf5 expression

Directory of Open Access Journals (Sweden)

Weng Chih-Wei

2007-01-01

Full Text Available Abstract Background Myf5 is one member of the basic helix-loop-helix family of transcription factors, and it functions as a myogenic factor that is important for the specification and differentiation of muscle cells. The expression of myf5 is somite- and stage-dependent during embryogenesis through a delicate regulation. However, this complex regulatory mechanism of myf5 is not clearly understood. Results We isolated a 156-kb bacterial artificial chromosome clone that includes an upstream 80-kb region and a downstream 70-kb region of zebrafish myf5 and generated a transgenic line carrying this 156-kb segment fused to a green fluorescent protein (GFP reporter gene. We find strong GFP expression in the most rostral somite and in the presomitic mesoderm during segmentation stages, similar to endogenous myf5 expression. Later, the GFP signals persist in caudal somites near the tail bud but are down-regulated in the older, rostral somites. During the pharyngula period, we detect GFP signals in pectoral fin buds, dorsal rostral myotomes, hypaxial myotomes, and inferior oblique and superior oblique muscles, a pattern that also corresponds well with endogenous myf5 transcripts. To characterize the specific upstream cis-elements that regulate this complex and dynamic expression pattern, we also generated several transgenic lines that harbor various lengths within the upstream 80-kb segment. We find that (1 the -80 kb/-9977 segment contains a fin and cranial muscle element and a notochord repressor; (2 the -9977/-6213 segment contains a strong repressive element that does not include the notochord-specific repressor; (3 the -6212/-2938 segment contains tissue-specific elements for bone and spinal cord; (4 the -2937/-291 segment contains an eye enhancer, and the -2937/-2457 segment is required for notochord and myocyte expression; and (5 the -290/-1 segment is responsible for basal transcription in somites and the presomitic mesoderm. Conclusion We suggest

Multispacecraft observations of energetic ions upstream and downstream of the bow shock

International Nuclear Information System (INIS)

Scholer, M.; Mobius, E.; Kistler, L.M.; Klecker, B.; Ipavich, F.M.; Department of Physics and Astronomy, University of Maryland, College Park)

1989-01-01

We present simultaneous measurements of energetic protons and alpha particles inside and outside of the magnetopause, immediately upstream, and downstream as well as further upstream of the bow shock. A comparison between the intensity at the bow shock and further upstream results in an e-folding distance at 30 keV of similar to 6.2 R/sub E/. After transformation of the angular distribution into the solar wind frame a diffusion coefficeint of κ/sub parallel/similar to 3 R/sub E/ is obtained from the anisotropy and the intensity gradient. Immediately downstream of the bow shock the anisotropy in the shock frame is directed toward the magnetopause. After transformation into the plasma rest frame the distribution is isotropic. The intensity in the magnetosheath just outside the magnetopause is smaller than the intensity behind the bow shock. Thus, in the magnetosheath there is no gradient or streaming in the upstream direction. The spectra, intensities, and relative abundances in the magnetosheath and inside the magnetosphere are totally different. These observations are consistent with first order Fermi acceleration at the bow shock and subsequent downstream convection, and exclude a magnetospheric source for these particles. Copyright American Geophysical Union 1989

Influence of Upstream and Downstream Compressor Stators on Rotor Exit Flow Field

Directory of Open Access Journals (Sweden)

Nicole L. Key

2014-01-01

Full Text Available Measurements acquired at the rotor exit plane illuminate the interaction of the rotor with the upstream vane row and the downstream vane row. The relative phase of the upstream and downstream vane rows is adjusted using vane clocking so that the effect of the upstream propagating potential field from the downstream stator can be distinguished from the effects associated with the wakes shed from the upstream stator. Unsteady absolute flow angle information shows that the downstream potential field causes the absolute flow angle to increase in the vicinity of the downstream stator leading edge. The presence of Stator 1 wake is also detected at this measurement plane using unsteady total pressure data. The rotor wakes are measured at different circumferential locations across the vane passage, and the influence of Stator 1 wake on the suction side of the rotor wake is evident. Also, the influence of the downstream stator is detected on the pressure side of the rotor wake for a particular clocking configuration. Understanding the role of the surrounding vane rows on rotor wake development will lead to improved comparison between experimental data and results from computational models.

Defective distal regulatory element at the 5' upstream of rat prolactin gene of steroid-nonresponsive GH-subclone.

Science.gov (United States)

Kumar, V; Wong, D T; Pasion, S G; Biswas, D K

1987-12-08

The prolactin-nonproducing (PRL-) GH cell strains (rat pituitary tumor cells in culture). GH12C1 and F1BGH12C1, do not respond to steroid hormones estradiol or hydrocortisone (HC). However, the stimulatory effect of estradiol and the inhibitory effect of hydrocortisone on prolactin synthesis can be demonstrated in the prolactin-producing GH cell strain, GH4C1. In this investigation we have examined the 5' end flanking region of rat prolactin (rat PRL) gene of steroid-responsive, GH4C1 cells to identify the positive and negative regulatory elements and to verify the status of these elements in steroid-nonresponsive F1BGH12C1 cells. Results presented in this report demonstrate that the basel level expression of the co-transferred Neo gene (neomycin phosphoribosyl transferase) is modulated by the distal upstream regulatory elements of rat PRL gene in response to steroid hormones. The expression of adjacent Neo gene is inhibited by dexamethasone and is stimulated by estradiol in transfectants carrying distal regulatory elements (SRE) of steroid-responsive cells. These responses are not observed in transfectants with the rat PRL upstream sequences derived from steroid-nonresponsive cells. The basal level expression of the host cell alpha-2 tubulin gene is not affected by dexamethasone. We report here the identification of the distal steroid regulatory element (SRE) located between 3.8 and 7.8 kb upstream of the transcription initiation site of rat PRL gene. Both the positive and the negative effects of steroid hormones can be identified within this upstream sequence. This distal SRE appears to be nonfunctional in steroid-nonresponsive cells. Though the proximal SRE is functional, the defect in the distal SRE makes the GH substrain nonresponsive to steroid hormones. These results suggest that both the proximal and the distal SREs are essential for the mediation of action of steroid hormones in GH cells.

Upstream ORF affects MYCN translation depending on exon 1b alternative splicing

International Nuclear Information System (INIS)

Besançon, Roger; Puisieux, Alain; Valsesia-Wittmann, Sandrine; Locher, Clara; Delloye-Bourgeois, Céline; Furhman, Lydie; Tutrone, Giovani; Bertrand, Christophe; Jallas, Anne-Catherine; Garin, Elisabeth

2009-01-01

The MYCN gene is transcribed into two major mRNAs: one full-length (MYCN) and one exon 1b-spliced (MYCN Δ1b ) mRNA. But nothing is known about their respective ability to translate the MYCN protein. Plasmids were prepared to enable translation from the upstream (uORF) and major ORF of the two MYCN transcripts. Translation was studied after transfection in neuroblastoma SH-EP cell line. Impact of the upstream AUG on translation was evaluated after directed mutagenesis. Functional study with the two MYCN mRNAs was conducted by a cell viability assay. Existence of a new protein encoded by the MYCN Δ1b uORF was explored by designing a rabbit polyclonal antibody against a specific epitope of this protein. Both are translated, but higher levels of protein were seen with MYCN Δ1b mRNA. An upstream ORF was shown to have positive cis-regulatory activity on translation from MYCN but not from MYCN Δ1b mRNA. In transfected SH-EP neuroblastoma cells, high MYCN dosage obtained with MYCN Δ1b mRNA translation induces an antiapoptotic effect after serum deprivation that was not observed with low MYCN expression obtained with MYCN mRNA. Here, we showed that MYCNOT: MYCN Overlap Transcript, a new protein of unknown function is translated from the upstream AUG of MYCN Δ1b mRNA. Existence of upstream ORF in MYCN transcripts leads to a new level of MYCN regulation. The resulting MYCN dosage has a weak but significant anti-apoptotic activity after intrinsic apoptosis induction

Lidar measurements of boundary layer depolarization and CCSEM-EDX compositional analysis of airborne particles on collocated passive samplers throughout the forest canopy during the 2016 airborne pollen season at UMBS, Pellston, MI

Science.gov (United States)

Wozniak, M. C.; Steiner, A.; Ault, A. P.; Kort, E. A.; Lersch, T.; Casuccio, G.

2017-12-01

Observations of airborne pollen are typically made with volumetric samplers that obtain a time-averaged pollen concentration at a single point. While spatial variations in surface pollen concentrations may be known with these samplers given multiple sampling sites, real-time boundary layer transport of pollen grains cannot be determined except by particle dispersion or tracer transport models. Recently, light detection and ranging (lidar) techniques, such as depolarization, have been used to measure pollen transport and optical properties throughout the boundary layer over time. Here, we use a ground-based micro-pulse lidar (MPL) to observe boundary layer vertical profiles before, during and after the peak anemophilous (wind-driven) pollen season. The lidar depolarization ratio is measured in tandem with the normalized R-squared backscatter (NRB) intensity to determine the contribution of aspherical particles to the scatterers present throughout the boundary layer. Measurements are taken from April 15 - July 12, 2016 at the University of Michigan Biological Station (UMBS) PROPHET outdoor research lab and tower within a largely forested region. UMBS is dominated by Acer rubrum, Betula papyrifera, Pinus resinosa, Quercus rubra and Pinus strobus, all of which began flowering on 4/19, 5/3, 5/25, 5/25 and 6/14, respectively. Temperature, relative humidity and wind speed measured on site determine daytime conditions conducive to pollen dispersion from flowers. Lidar depolarization ratios between 0.08-0.14 and higher are observed in the daytime boundary layer on days shortly after the flowering dates of the aforementioned species, elevated above the background level of 0.06 or less. Lidar observations are supplemented with aerosol compositional analysis determined by computer-controlled scanning electron microscopy and energy-dispersive X-ray spectroscopy (CCSEM-EDX) on passive sampler data from below, within and above the forest canopy at PROPHET tower. Particles are

Monitoring the remediation of a near shore waste disposal site in Antarctica using the amphipod Paramoera walkeri and diffusive gradients in thin films (DGTs)

International Nuclear Information System (INIS)

Stark, Jonathan S. . E-mail jonny.stark@aad.gov.au; Johnstone, Glenn J.; Palmer, Anne S.; Snape, Ian; Larner, Bronwyn L.; Riddle, Martin J.

2006-01-01

The water quality of a marine embayment (Brown Bay) was monitored during the remediation of an abandoned waste disposal site at Casey Station, East Antarctica, using a combination of biomonitoring and chemical methods. The Antarctic amphipod Paramoera walkeri, in field mesocosms suspended in the water column, was deployed adjacent to the site and at two reference sites for periods of 14 days, repeated three times during the remediation period (December to February). Diffusive gradients in thin film (DGT) samplers were deployed for the same periods to provide estimates of dissolved metals. No difference in mortality of amphipods was observed between Brown Bay and reference sites. There were significant differences, however, in accumulated metal concentrations between amphipods from Brown Bay and reference sites, with greater concentrations of antimony, copper, cadmium, lead, iron and tin at Brown Bay. The melt water/runoff treatment strategy employed for the remediation was successful in preventing acute toxic effects, but water quality was reduced at Brown Bay, where increased metal bioavailability may have been high enough to induce chronic effects in some biota. DGT samplers were less sensitive than amphipods in detecting differences in metal concentrations between sites, indicating that metals bound to suspended particulates were a potentially significant source of contamination

Upstream waves in Saturn's foreshock

Science.gov (United States)

Bavassano Cattaneo, M. B.; Cattaneo, P.; Moreno, G.; Lepping, R. P.

1991-01-01

An analysis based on plasma and magnetic-field data obtained from Voyager 1 during its Saturn encounter is reported. The plasma data provided every 96 sec and magnetic-field data averaged over 48 sec are utilized. The evidence of upstream waves at Saturn are detected. The waves have a period, in the spacecraft frame, of about 550 sec and a relative amplitude larger than 0.3, are left- and right-hand elliptically polarized, and propagate at about 30 deg with respect to the average magnetic field. The appearance of the waves is correlated with the spacecraft being magnetically connected to the bow shock.

Water sampling at the Berge Helene FPSO at Chinguetti field in Mauritania using passive samplers

NARCIS (Netherlands)

Korytar, P.; Galien, van der W.

2007-01-01

Three rounds of water sampling were performed at the Berge Helene FPSO at the Chinguetti field in Mauritania using passive samplers attached to the FPSO to determine the levels of contamination that could potentially accumulate in organisms. Two rounds were carried out prior to the commencement of

Assessment of polycyclic aromatic hydrocarbon contamination of the Bílina River (Czech Republic using passive water samplers and fish biliary metabolites

Directory of Open Access Journals (Sweden)

Jana Blahová

2011-01-01

Full Text Available The aim of the study was to assess polycyclic aromatic hydrocarbon (PAH contamination on the Bílina River (the Czech Republic by measurement of three PAH biliary metabolites in fish and 16 PAHs in passive samplers. A total of sixty-one fish were collected; the indicator species were chub (Leuciscus cephalus L.; n = 25, roach (Rutilus rutilus L.; n = 17 and brown trout (Salmo trutta m. fario L.; n = 19. Three biliary PAH metabolites were measured: 1-hydroxypyrene (1-OHP, 2-naphtol, and 1-hydroxyphenanthrene, but only 1-OHP was detected in all fish. The highest median value of 32.3 ng·mg-1of 1-OHP was found at Ústí nad Labem, while the lowest median value of 27.6 ng·mg-1was found in the control site, Březenec. No significant differences (P < 0.05 among the sites were found. The highest concentration of PAH was detected in Litvínov-Záluží (172.0 ng·l-1 and the lowest concentration (7.9 ng·l-1 was detected in Březenec. A positive, but non-significant correlation (rs = 0.8 was confirmed between biliary 1-OHP and total PAH in passive samplers. These results indicate the highest pollution in the middle stretches of the Bílina River, especially at Litvínov-Záluží. We confirmed 1-OHP as the most prevalent PAH biliary metabolite in fish that could be used as a biomarker for assessment of PAH pollution of the aquatic ecosystem. The main importance of the present study is in the combination of biochemical and chemical monitoring that provides complex evaluation of aquatic environment contamination. It was the first study on the Bílina River, in which the assessment of PAH contamination in the aquatic ecosystem was realized using combination of biotic and abiotic monitoring.

Performance evaluation and accuracy of passive capillary samplers (PCAPs) for estimating real-time drainage water fluxes

Science.gov (United States)

Successful monitoring of pollutant transport through the soil profile requires accurate, reliable, and appropriate instrumentation to measure amount of drainage water or flux within the vadose layer. We evaluated the performance and accuracy of automated passive capillary wick samplers (PCAPs) for ...

Distribution of CpG Motifs in Upstream Gene Domains in a Reef Coral and Sea Anemone: Implications for Epigenetics in Cnidarians.

Science.gov (United States)

Marsh, Adam G; Hoadley, Kenneth D; Warner, Mark E

2016-01-01

Coral reefs are under assault from stressors including global warming, ocean acidification, and urbanization. Knowing how these factors impact the future fate of reefs requires delineating stress responses across ecological, organismal and cellular scales. Recent advances in coral reef biology have integrated molecular processes with ecological fitness and have identified putative suites of temperature acclimation genes in a Scleractinian coral Acropora hyacinthus. We wondered what unique characteristics of these genes determined their coordinate expression in response to temperature acclimation, and whether or not other corals and cnidarians would likewise possess these features. Here, we focus on cytosine methylation as an epigenetic DNA modification that is responsive to environmental stressors. We identify common conserved patterns of cytosine-guanosine dinucleotide (CpG) motif frequencies in upstream promoter domains of different functional gene groups in two cnidarian genomes: a coral (Acropora digitifera) and an anemone (Nematostella vectensis). Our analyses show that CpG motif frequencies are prominent in the promoter domains of functional genes associated with environmental adaptation, particularly those identified in A. hyacinthus. Densities of CpG sites in upstream promoter domains near the transcriptional start site (TSS) are 1.38x higher than genomic background levels upstream of -2000 bp from the TSS. The increase in CpG usage suggests selection to allow for DNA methylation events to occur more frequently within 1 kb of the TSS. In addition, observed shifts in CpG densities among functional groups of genes suggests a potential role for epigenetic DNA methylation within promoter domains to impact functional gene expression responses in A. digitifera and N. vectensis. Identifying promoter epigenetic sequence motifs among genes within specific functional groups establishes an approach to describe integrated cellular responses to environmental stress in

Distribution of CpG Motifs in Upstream Gene Domains in a Reef Coral and Sea Anemone: Implications for Epigenetics in Cnidarians.

Directory of Open Access Journals (Sweden)

Adam G Marsh

Full Text Available Coral reefs are under assault from stressors including global warming, ocean acidification, and urbanization. Knowing how these factors impact the future fate of reefs requires delineating stress responses across ecological, organismal and cellular scales. Recent advances in coral reef biology have integrated molecular processes with ecological fitness and have identified putative suites of temperature acclimation genes in a Scleractinian coral Acropora hyacinthus. We wondered what unique characteristics of these genes determined their coordinate expression in response to temperature acclimation, and whether or not other corals and cnidarians would likewise possess these features. Here, we focus on cytosine methylation as an epigenetic DNA modification that is responsive to environmental stressors. We identify common conserved patterns of cytosine-guanosine dinucleotide (CpG motif frequencies in upstream promoter domains of different functional gene groups in two cnidarian genomes: a coral (Acropora digitifera and an anemone (Nematostella vectensis. Our analyses show that CpG motif frequencies are prominent in the promoter domains of functional genes associated with environmental adaptation, particularly those identified in A. hyacinthus. Densities of CpG sites in upstream promoter domains near the transcriptional start site (TSS are 1.38x higher than genomic background levels upstream of -2000 bp from the TSS. The increase in CpG usage suggests selection to allow for DNA methylation events to occur more frequently within 1 kb of the TSS. In addition, observed shifts in CpG densities among functional groups of genes suggests a potential role for epigenetic DNA methylation within promoter domains to impact functional gene expression responses in A. digitifera and N. vectensis. Identifying promoter epigenetic sequence motifs among genes within specific functional groups establishes an approach to describe integrated cellular responses to

High-frequency, long-duration water sampling in acid mine drainage studies: a short review of current methods and recent advances in automated water samplers

Science.gov (United States)

Chapin, Thomas

2015-01-01

Hand-collected grab samples are the most common water sampling method but using grab sampling to monitor temporally variable aquatic processes such as diel metal cycling or episodic events is rarely feasible or cost-effective. Currently available automated samplers are a proven, widely used technology and typically collect up to 24 samples during a deployment. However, these automated samplers are not well suited for long-term sampling in remote areas or in freezing conditions. There is a critical need for low-cost, long-duration, high-frequency water sampling technology to improve our understanding of the geochemical response to temporally variable processes. This review article will examine recent developments in automated water sampler technology and utilize selected field data from acid mine drainage studies to illustrate the utility of high-frequency, long-duration water sampling.

Analysis of an upstream weighted collocation approximation to the transport equation

International Nuclear Information System (INIS)

Shapiro, A.; Pinder, G.F.

1981-01-01

The numerical behavior of a modified orthogonal collocation method, as applied to the transport equations, can be examined through the use of a Fourier series analysis. The necessity of such a study becomes apparent in the analysis of several techniques which emulate classical upstream weighting schemes. These techniques are employed in orthogonal collocation and other numerical methods as a means of handling parabolic partial differential equations with significant first-order terms. Divergent behavior can be shown to exist in one upstream weighting method applied to orthogonal collocation

Spawning chronology, nest site selection and nest success of smallmouth bass during benign streamflow conditions

Science.gov (United States)

Dauwalter, D.C.; Fisher, W.L.

2007-01-01

We documented the nesting chronology, nest site selection and nest success of smallmouth bass Micropterus dolomieu in an upstream (4th order) and downstream (5th order) reach of Baron Fork Creek, Oklahoma. Males started nesting in mid-Apr. when water temperatures increased to 16.9 C upstream, and in late-Apr. when temperatures increased to 16.2 C downstream. Streamflows were low (77% upstream to 82% downstream of mean Apr. streamflow, and 12 and 18% of meanjun. streamflow; 47 and 55 y of record), and decreased throughout the spawning period. Larger males nested first upstream, as has been observed in other populations, but not downstream. Upstream, progeny in 62 of 153 nests developed to swim-up stage. Downstream, progeny in 31 of 73 nests developed to swim-up. Nesting densities upstream (147/km) and downstream (100/km) were both higher than any densities previously reported. Males selected nest sites with intermediate water depths, low water velocity and near cover, behavior that is typical of smallmouth bass. Documented nest failures resulted from human disturbance, angling, and longear sunfish predation. Logistic exposure models showed that water velocity at the nest was negatively related and length of the guarding male was positively related to nest success upstream. Male length and number of degree days were both positively related to nest success downstream. Our results, and those of other studies, suggest that biological factors account for most nest failures during benign (stable, low flow) streamflow conditions, whereas nest failures attributed to substrate mobility or nest abandonment dominate when harsh streamflow conditions (spring floods) coincide with the spawning season.

Operating manual for Ford's Farm Range air samplers

International Nuclear Information System (INIS)

Glissmeyer, J.A.; Halverson, M.A.

1980-10-01

An air-sampling program was designed for a target enclosure at the Ford's Farm Range, Aberdeen Proving Ground, Maryland, where the Army test-fires tungsten and depleted-uranium armor penetrators. The primary potential particle inhalation hazard is depleted uranium. The sampling program includes workplace and filtered exhaust air sampling. Conventional isokinetic stack sampling was employed for the filtered exhaust air. Because of the need for rapid monitor response to concentration increases and decreases, conventional radioactive particle monitors were not used. Instead, real-time aerosol monitors employing a light-scattering technique were used for monitors requiring a fast response. For other monitoring functions, piezoelectric and beta-attenuation respirable-particle sampling techniques were used. The application of these technologies to the monitoring of airborne radioactive contaminants is addressed. Sampler installation and operation are detailed

ENHANCING THE ROLE OF STAKEHOLDERS IN THE MANAGEMENT OF UPSTREAM CILIWUNG WATERSHED

Directory of Open Access Journals (Sweden)

Iis Alviya

2016-08-01

Full Text Available Stakeholders have a ver y important role interm of the management of upstream watershed. Thus, the common understanding on the existence and role of stakeholders is an important factor in order to achieve good governance of watershed management, leading to the attainment of environmental, social and economic benefits. This paper aims to analyse the role, interests, and cooperation among stakeholders and its relationship with the condition of upper Ciliwung watershed. Stakeholder analysis was used in this study to identify stakeholders, to categorize them, and to investigate the relationship between stakeholders. The analysis showed the lack of cooperation among stakeholders both between key stakeholders with primar y stakeholders. This resulted in lack of communities' understanding on the benefits and the importance of conservation activities in the upstream Ciliwung watershed. Meanwhile, the cooperation between key stakeholders and supporting stakeholders, especially the providers of funds, was relatively better/stronger. This can be seen from a better management of inter-agency cooperation in the upstream Ciliwung watershed, although the effort was tend to be project-oriented. Therefore, communication forum need to be established, to taking role for synchronizing , collaborating and coordinating stakeholders' efforts, so that the management programs of upstream Ciliwung watershed can be integrated.

Comparison of dialysis membrane diffusion samplers and two purging methods in bedrock wells

Science.gov (United States)

Imbrigiotta, T.E.; Ehlke, T.A.; Lacombe, P.J.; Dale, J.M.; ,

2002-01-01

Collection of ground-water samples from bedrock wells using low-flow purging techniques is problematic because of the random spacing, variable hydraulic conductivity, and variable contamination of contributing fractures in each well's open interval. To test alternatives to this purging method, a field comparison of three ground-water-sampling techniques was conducted on wells in fractured bedrock at a site contaminated primarily with volatile organic compounds. Constituent concentrations in samples collected with a diffusion sampler constructed from dialysis membrane material were compared to those in samples collected from the same wells with a standard low-flow purging technique and a hybrid (high-flow/low-flow) purging technique. Concentrations of trichloroethene, cis-1,2-dichloroethene, vinyl chloride, calcium, chloride, and alkalinity agreed well among samples collected with all three techniques in 9 of the 10 wells tested. Iron concentrations varied more than those of the other parameters, but their pattern of variation was not consistent. Overall, the results of nonparametric analysis of variance testing on the nine wells sampled twice showed no statistically significant difference at the 95-percent confidence level among the concentrations of volatile organic compounds or inorganic constituents recovered by use of any of the three sampling techniques.

DOWNSTREAM ECOCIDE FROM UPSTREAM WATER PIRACY

OpenAIRE

Miah Muhammad Adel

2012-01-01

Upstream India and downstream Bangladesh share more than 50 international rivers. India has set up water diversion constructions in more than 50% of these rivers, the largest one being on the Bangladeshâs northwest upon the Ganges River, puts Bangladeshâs Gangetic ecosystem at stake. In some border rivers, India has set up groins on her side of river banks. Also, Indian side pumps Bangladesh river water stealthily from border-rivers. Further, India is constructing another dam and reservoir up...

Sources and distribution of organic compounds using passive samplers in Lake Mead National Recreation Area, Nevada and Arizona, and their implications for potential effects on aquatic biota.

Science.gov (United States)

Rosen, Michael R.; Alvarez, David A.; Goodbred, Steven L.; Leiker, Thomas J.; Patino, Reynaldo

2009-01-01

Th e delineation of lateral and vertical gradients of organic contaminants in lakes is hampered by low concentrations and nondetection of many organic compounds in water. Passive samplers (semipermeable membrane devices [SPMDs] and polar organic chemical integrative samplers [POCIS]) are well suited for assessing gradients because they can detect synthetic organic

The WW domain protein Kibra acts upstream of Hippo in Drosophila

DEFF Research Database (Denmark)

Baumgartner, Roland; Poernbacher, Ingrid; Buser, Nathalie

2010-01-01

inactivating the transcriptional coactivator Yorkie is well established, much less is known about the upstream events that regulate Hippo signaling activity. The FERM domain proteins Expanded and Merlin appear to represent two different signaling branches that feed into the Hippo pathway. Signaling...... by the atypical cadherin Fat may act via Expanded, but how Merlin is regulated has remained elusive. Here, we show that the WW domain protein Kibra is a Hippo signaling component upstream of Hippo and Merlin. Kibra acts synergistically with Expanded, and it physically interacts with Merlin. Thus, Kibra...

Impact of upstream industrial effluents on irrigation water quality ...

African Journals Online (AJOL)

Impact of upstream industrial effluents on irrigation water quality, soils and ... Knowledge of irrigation water quality is critical to predicting, managing and reducing salt ... Presence of heavy metals in concentration higher than the recommended ...

Direct analysis of airborne mite allergen (Der f1) in the residential atmosphere by chemifluorescent immunoassay using bioaerosol sampler.

Science.gov (United States)

Miyajima, Kumiko; Suzuki, Yurika; Miki, Daisuke; Arai, Moeka; Arakawa, Takahiro; Shimomura, Hiroji; Shiba, Kiyoko; Mitsubayashi, Kohji

2014-06-01

Dermatophagoides farinae allergen (Der f1) is one of the most important indoor allergens associated with allergic diseases in humans. Mite allergen Der f1 is usually associated with particles of high molecular weight; thus, Der f1 is generally present in settled dust. However, a small quantity of Der f1 can be aerosolized and become an airborne component. Until now, a reliable method of detecting airborne Der f1 has not been developed. The aim of this study was to develop a fiber-optic chemifluorescent immunoassay for the detection of airborne Der f1. In this method, the Der f1 concentration measured on the basis of the intensity of fluorescence amplified by an enzymatic reaction between the labeled enzyme by a detection antibody and a fluorescent substrate. The measured Der f1 concentration was in the range from 0.49 to 250 ng/ml and a similar range was found by enzyme-linked immunosorbent assay (ELISA). This method was proved to be highly sensitive to Der f1 compared with other airborne allergens. For the implementation of airborne allergen measurement in a residential environment, a bioaerosol sampler was constructed. The airborne allergen generated by a nebulizer was conveyed to a newly sampler we developed for collecting airborne Der f1. The sampler was composed of polymethyl methacrylate (PMMA) cells for gas/liquid phases and some porous membranes which were sandwiched in between the two phases. Der f1 in air was collected by the sampler and measured using the fiber-optic immunoassay system. The concentration of Der f1 in aerosolized standards was in the range from 0.125 to 2.0 mg/m(3) and the collection rate of the device was approximately 0.2%. © 2013 Elsevier B.V. All rights reserved.

Water Stress in Global Transboundary River Basins: Significance of Upstream Water Use on Downstream Stress

Science.gov (United States)

Munia, H.; Guillaume, J. H. A.; Mirumachi, N.; Porkka,M.; Wada, Yoshihide; Kummu, M.

2016-01-01

Growing population and water demand have increased pressure on water resources in various parts of the globe, including many transboundary river basins. While the impacts of upstream water use on downstream water availability have been analyzed in many of these international river basins, this has not been systematically done at the global scale using coherent and comparable datasets. In this study, we aim to assess the change in downstream water stress due to upstream water use in the world's transboundary river basins. Water stress was first calculated considering only local water use of each sub-basin based on country-basin mesh, then compared with the situation when upstream water use was subtracted from downstream water availability. Wefound that water stress was generally already high when considering only local water use, affecting 0.95-1.44 billion people or 33%-51% of the population in transboundary river basins. After accounting for upstream water use, stress level increased by at least 1 percentage-point for 30-65 sub-basins, affecting 0.29-1.13 billion people. Altogether 288 out of 298 middle-stream and downstream sub-basin areas experienced some change in stress level. Further, we assessed whether there is a link between increased water stress due to upstream water use and the number of conflictive and cooperative events in the transboundary river basins, as captured by two prominent databases. No direct relationship was found. This supports the argument that conflicts and cooperation events originate from a combination of different drivers, among which upstream-induced water stress may play a role. Our findings contribute to better understanding of upstream-downstream dynamics in water stress to help address water allocation problems.

Determination of the radioiodine species in the exhaust air of nuclear facilities

International Nuclear Information System (INIS)

Deuber, H.

1977-01-01

Using the selective I 2 sorption materials DSM 10 and DSM 11 measurements were performed with radioiodine species samplers in the exhaust air of a research reactor and of several nuclear power stations (BWR, PWR). The radioiodine species samplers were used upstream and downstream of iodine filters (containment exhaust air stand-by filter, shutoff room exhaust air filter) as well as in the exhaust air of the stack. The results obtained by use of DSM 10 and DSM 11 generally agreed. The percentage of aerosol iodine was low in all cases ( [de

PM10 sampler deposited air particulates: Ascertaining uniformity of sample on filter through rotated exposure to radiation

International Nuclear Information System (INIS)

Owoade, Oyediran K.; Olise, Felix S.; Obioh, Imoh B.; Olaniyi, Hezekiah B.; Bolzacchini, Ezio; Ferrero, Luca; Perrone, Grazia

2006-01-01

For reproducibility of analytical results of samples deposited on filters using PM 10 sampler, homogeneity of the sample on the filter is very important especially when the size of the X-ray beam for the analysis is less than the size of filter. It is against this background that the air particulate samples collected on using PM 10 samplers are analysed to determine the elemental concentrations. Each sample was divided into four quadrants and each was analysed under same conditions to determine if the particles were deposited uniformly over the filter. Each analysis was done using EDXRF technique. The spectrometer consists of four secondary targets, which are automatically switched to in sequence in analysing each sample. The concentration of various elements detected was determined using TURBOQUANT (a brand name for a SPECTRO method which is used for screening analysis). Sixteen elements were detected in every sample. Results show that there was less than 10% deviation in the concentrations in different quadrants. There were a few elements like Ba, Cs, etc., which have deviation greater than 20%. The concentrations of these latter elements were close to detection limits of the spectrometer. We conclude that the analytical result of particulate samples deposited on filters by the PM 10 sampler can be reliable in terms of the homogeneity of the deposition. For such analytes with low concentrations, it would be important that the sampling time be increased to allow for higher mass deposition on the filter

Sector report: Malaysia. Upstream oil and gas industry

International Nuclear Information System (INIS)

1997-01-01

This report is one of a series designed to introduce British exporters to the opportunities offered by the Malaysian market in oil and natural gas. The report includes Malaysia's oil and gas reserves, production, exploration, major profits upstream, production sharing contracts, pipeline construction, operators in production, service sector, and Petronas. (UK)

A minimally invasive micro sampler for quantitative sampling with an ultrahigh-aspect-ratio microneedle and a PDMS actuator.

Science.gov (United States)

Liu, Long; Wang, Yan; Yao, Jinyuan; Yang, Cuijun; Ding, Guifu

2016-08-01

This study describes a novel micro sampler consisting of an ultrahigh-aspect-ratio microneedle and a PDMS actuator. The microneedle was fabricated by a new method which introduced reshaped photoresist technology to form a flow channel inside. The microneedle includes two parts: shaft and pedestal. In this study, the shaft length is 1500 μm with a 45° taper angle on the tip and pedestal is 1000 μm. Besides, the shaft and pedestal are connected by an arc connection structure with a length of 600 μm. The microneedles have sufficient mechanical strength to insert into skin with a wide safety margin which was proved by mechanics tests. Moreover, a PDMS actuator with a chamber inside was designed and fabricated in this study. The chamber, acting as a reservoir in sampling process as well as providing power, was optimized by finite element analysis (FEA) to decrease dead volume and improve sampling precision. The micro sampler just needs finger press to activate the sampling process as well as used for quantitative micro injection to some extent. And a volume of 31.5 ± 0.8 μl blood was successfully sampled from the ear artery of a rabbit. This micro sampler is suitable for micro sampling for diagnose or therapy in biomedical field.

Strategic human resources study of the upstream petroleum industry : the decade ahead

International Nuclear Information System (INIS)

2003-10-01

This report presents the results of a 10 month study of the human resources issues in Canada's upstream petroleum industry. The study identifies workforce demographics, skills, and supply and demand. It also discusses the impact of technology and other key challenges facing human resources issues. The upstream petroleum industry includes exploration and production, service industries, pipeline transmission, natural gas processing, and heavy oil and bitumen extracting and upgrading. The study defined four regions in Canada: Western Canada Sedimentary Basin, the oil sands, the north, and the east coast. The main influences on the management practices within the upstream petroleum industry are: globalization; cyclical economic conditions; operational excellence business models; government regulatory requirements; stakeholder expectations for involvement; technological advances; changing demographics, and workplace skills. The study also presented suggestions for changes in best practices to improve the efficiency and effectiveness of product and service delivery. refs., tabs., figs

Sources identification of the atmospheric aerosol at urban and suburban sites in Indonesia by positive matrix factorization

International Nuclear Information System (INIS)

Santoso, Muhayatun; Hopke, Philip K.; Hidayat, Achmad; Diah Dwiana L

2008-01-01

Samples of fine and coarse fractions of airborne particulate matter were collected in Indonesia (west central Java) at an urban site in Bandung and in suburban Lembang from January 2002 to December 2004. The samples were collected using a Gent stacked filter sampler in two size fractions of 2.5-10 mass at both sites comes from soil dust and road dust. The biomass burning factor contributes about 40% of the PM 2.5 mass in case of suburban Lembang and about 20% in urban Bandung

pH-Modulated Watson-Crick duplex-quadruplex equilibria of guanine-rich and cytosine-rich DNA sequences 140 base pairs upstream of the c-kit transcription initiation site.

Science.gov (United States)

Bucek, Pavel; Jaumot, Joaquim; Aviñó, Anna; Eritja, Ramon; Gargallo, Raimundo

2009-11-23

Guanine-rich regions of DNA are sequences capable of forming G-quadruplex structures. The formation of a G-quadruplex structure in a region 140 base pairs (bp) upstream of the c-kit transcription initiation site was recently proposed (Fernando et al., Biochemistry, 2006, 45, 7854). In the present study, the acid-base equilibria and the thermally induced unfolding of the structures formed by a guanine-rich region and by its complementary cytosine-rich strand in c-kit were studied by means of circular dichroism and molecular absorption spectroscopies. In addition, competition between the Watson-Crick duplex and the isolated structures was studied as a function of pH value and temperature. Multivariate data analysis methods based on both hard and soft modeling were used to allow accurate quantification of the various acid-base species present in the mixtures. Results showed that the G-quadruplex and i-motif coexist with the Watson-Crick duplex over the pH range from 3.0 to 6.5, approximately, under the experimental conditions tested in this study. At pH 7.0, the duplex is practically the only species present.

Simplified unified analysis of switched-RC passive mixers, samplers, and N -Path filters using the adjoint network

NARCIS (Netherlands)

Pavan, Shanthi; Klumperink, Eric A.M.

2017-01-01

Recent innovations in software defined CMOS radio transceiver architectures heavily rely on high linearity switched-RC sampler and passive-mixer circuits, driven by digitally programmable multiphase clocks. Although seemingly simple, the frequency domain analysis of these linear periodically time

Enhancer elements upstream of the SHOX gene are active in the developing limb.

Science.gov (United States)

Durand, Claudia; Bangs, Fiona; Signolet, Jason; Decker, Eva; Tickle, Cheryll; Rappold, Gudrun

2010-05-01

Léri-Weill Dyschondrosteosis (LWD) is a dominant skeletal disorder characterized by short stature and distinct bone anomalies. SHOX gene mutations and deletions of regulatory elements downstream of SHOX resulting in haploinsufficiency have been found in patients with LWD. SHOX encodes a homeodomain transcription factor and is known to be expressed in the developing limb. We have now analyzed the regulatory significance of the region upstream of the SHOX gene. By comparative genomic analyses, we identified several conserved non-coding elements, which subsequently were tested in an in ovo enhancer assay in both chicken limb bud and cornea, where SHOX is also expressed. In this assay, we found three enhancers to be active in the developing chicken limb, but none were functional in the developing cornea. A screening of 60 LWD patients with an intact SHOX coding and downstream region did not yield any deletion of the upstream enhancer region. Thus, we speculate that SHOX upstream deletions occur at a lower frequency because of the structural organization of this genomic region and/or that SHOX upstream deletions may cause a phenotype that differs from the one observed in LWD.

Bioaccumulation Using Surrogate Samplers (Bass): Evaluation Of A Passive Sampler As An Alternative Monitoring Tool For Environmental Contaminants At The Savannah River Site

International Nuclear Information System (INIS)

Paller, M.; Knox, A.; Kuhne, W.; Blas, S.

2015-01-01

DOE sites conduct traditional environmental monitoring programs that require collecting, processing, and analyzing water, sediment, and fish samples. However, recently developed passive sampling technologies, such as Diffusive Gradient in Thin films (DGT), may measure the chemical phases that are available and toxic to organisms (the bioavailable fraction), thereby producing more accurate and economical results than traditional methods. Our laboratory study showed that dissolved copper concentrations measured by DGT probes were strongly correlated with the uptake of copper by Lumbriculus variegatus, an aquatic worm, and with concentrations of copper measured by conventional methods. Dissolved copper concentrations in DGT probes increased with time of exposure, paralleling the increase in copper with time that ocurred in Lumbriculus. Additional studies with a combination of seven dissolved metals showed similar results. These findings support the use of DGT as a biomimetic monitoring tool and provide a basis for refinement of these methods for cost-effective environmental monitoring at DOE sites.

Restructuring: new relationships between the oil companies and the upstream oil firms

International Nuclear Information System (INIS)

Barreau, S.

2001-11-01

Since the 1986 oil shock, international oil companies have focused on their base competencies, concentrating on activities viewed as their core businesses and steadily increasing the number of tasks to be subcontracted to the upstream oil and gas service sector. The upstream oil and gas service companies had to be restructured to face this new challenge. The strategies they launched at the end of the 80's were varied. Some firms became largely integrated (Schlumberger, Baker Hughes, Halliburton) whereas other firms chose to broaden their range of services. However generally, they opted for external investment which led to an important wave of mergers and acquisitions. The first part characterizes the upstream oil and gas sector by introducing the main oil and gas service firms and their recent strategic evolution. This concludes with both an economic valuation and a typology of attempted growth strategies. To illustrate this, a matrix has been created to characterise the dynamic paths of the oil and gas service firms. The purpose of the second part is to consider the economic theories related to industrial strategies. The strategies of innovation, market protection, vertical integration and diversification have been studied to illustrate the main conclusion which is that the aim of all these strategies was to change the relationships between the oil companies and the upstream oil and gas service firms. (author)

The upstream escape of energized solar wind protons from the bow shock

International Nuclear Information System (INIS)

Greenstadt, E.W.

1975-01-01

Recently, there have been some systematic observations of backstreaming protons at the Earth's bow shock with parallel velocity components and total energies much too high to be associated with the usual long-period upstream waves or to be produced by Sonnerup's simple reflection process (Lin et al., 1974), and these protons (30-100keV) were attributed to some unknown acceleration mechanism in the upstream region. The observations of Lof et al. involved protons in high pitch angle, and, although their reasons for favoring an upstream acceleration were quite different, it may seem intuitive that high pitch angle particles would have difficulty escaping the shock, especially at large field-normal angles. Such an inference would superficially support the notion of energization outside the bow shock. It seems worthwhile therefore to examine the extent to which the geometry of individual particle motion alone might select among reflected particles those that can escape upstream and those that cannot. In this paper the geometry of escape is described and some simple numerical examples are worked out for a few special cases. It is found that protons with rather high energies and pitch angles can escape the shock at only marginally quasi-parallel field orientations (i.e., thetasub(nB) approximately 50 0 ), even if they have quite moderate speeds parallel to B. (Auth.)

The atmosphere as a source/sink of polychlorinated biphenyls to/from the Lower Duwamish Waterway Superfund site

International Nuclear Information System (INIS)

Apell, Jennifer N.; Gschwend, Philip M.

2017-01-01

Waterbodies polluted with polychlorinated biphenyls (PCBs) may cause the air in the surrounding area to become PCB-contaminated. Conversely, when a waterbody is located in or near an urban area, the deposition of atmospheric PCBs may act as a low-level, ongoing source of PCB contamination to that water. Distinguishing these situations is necessary to be protective of human populations and to guide efforts seeking to cleanup such aquatic ecosystems. To assess the situation at the Lower Duwamish Waterway (LDW) Superfund site, low-density polyethylene passive samplers were deployed in the summer of 2015 to quantify freely dissolved water and gaseous air concentrations of PCBs thereby enabling estimates of the direction and magnitude of air-water exchange of PCB congeners. For the sum of the 27 PCB congeners, average concentrations were 220 pg/m 3 (95% C.I.: 80–610) in the air and 320 pg/L (95% C.I.: 110–960) in the water. The sum of air-water exchange fluxes of these PCB congeners was estimated to be 68 ng/m 2 /day (95% C.I.: 30–148) into the lower atmosphere, contrasting with the reported wet and dry depositional flux of only 5.5 ng/m 2 /day (95% C.I.: 1–38) from the air into the water. Therefore, the atmosphere was ultimately a sink of PCBs from the LDW Superfund site, at least under 2015 summertime conditions. However, we conclude that air-water exchange of PCBs is likely only a minor sink of PCBs from the LDW and only a minor source of contamination to the region's local atmosphere. - Highlights: • Passive samplers were used to estimate air and water concentrations. • At this site, PCBs were being transported from the water into the local atmosphere. • Air-water exchange was likely only a minor sink of PCBs for the LDW site. • The LDW was likely only a minor source of PCBs to the local atmosphere. - Air-water exchange of PCBs from the LDW Superfund site, calculated using passive sampler data, was determined to be a minor sink of PCBs from

Retrotransposons. An RNA polymerase III subunit determines sites of retrotransposon integration.

Science.gov (United States)

Bridier-Nahmias, Antoine; Tchalikian-Cosson, Aurélie; Baller, Joshua A; Menouni, Rachid; Fayol, Hélène; Flores, Amando; Saïb, Ali; Werner, Michel; Voytas, Daniel F; Lesage, Pascale

2015-05-01

Mobile genetic elements are ubiquitous. Their integration site influences genome stability and gene expression. The Ty1 retrotransposon of the yeast Saccharomyces cerevisiae integrates upstream of RNA polymerase III (Pol III)-transcribed genes, yet the primary determinant of target specificity has remained elusive. Here we describe an interaction between Ty1 integrase and the AC40 subunit of Pol III and demonstrate that AC40 is the predominant determinant targeting Ty1 integration upstream of Pol III-transcribed genes. Lack of an integrase-AC40 interaction dramatically alters target site choice, leading to a redistribution of Ty1 insertions in the genome, mainly to chromosome ends. The mechanism of target specificity allows Ty1 to proliferate and yet minimizes genetic damage to its host. Copyright © 2015, American Association for the Advancement of Science.

A Field Evaluation of Performance Reference Compound Based Estimates of Cfree Using Water Column Deployed Passive Samplers

Science.gov (United States)

Low-Density polyethylene (LDPE) sheets are often used as passive samplers for aquatic environmental monitoring to measure the freely dissolved concentrations of hydrophobic organic contaminants (HOCs). HOCs that are freely dissolved in water (Cfree) will partition into the LDPE u...

Upstream pressure variations associated with the bow shock and their effects on the magnetosphere

International Nuclear Information System (INIS)

Fairfield, D.H.; Baumjohann, W.; Paschmann, G.; Luehr, H.; Sibeck, D.G.

1990-01-01

Magnetic field enhancements and depressions on the time scales of minutes were frequently observed simultaneously by the AMPTE CCE, GOES 5, and GOES 6 spacecraft in the subsolar magnetosphere. The source of these perturbations has been detected in the high time resolution AMPTE IRM measurements of the kinetic pressure of the solar wind upstream of the bow shock. It is argued that these upstream pressure variations are not inherent in the solar wind but rather are associated with the bow shock. This conclusion follows from the facts that (1) the upstream field strength and the density associated with the perturbations are highly correlated with each other whereas these quantities tend to be anticorrelated in the undisturbed solar wind, and (2) the upstream perturbations occur within the foreshock or at its boundary. The results imply a mode of interaction between the solar wind and the magnetosphere whereby density changes produced in the foreshock subsequently convect through the bow shock and impinge on the magnetosphere. Also velocity decreases deep within the foreshock sometimes reach many tens of kilometers per second and may be associated with further pressure variations as a changing interplanetary field direction changes the foreshock geometry. Upstream pressure perturbations should create significant effects on the magnetopause and at the foot of nearby field lines that lead to the polar cusp ionosphere

Determination of respirable-sized crystalline silica in different ambient environments in the United Kingdom with a mobile high flow rate sampler utilising porous foams to achieve the required particle size selection

Science.gov (United States)

Stacey, Peter; Thorpe, Andrew; Roberts, Paul; Butler, Owen

2018-06-01

Inhalation of respirable crystalline silica (RCS) can cause diseases including silicosis and cancer. Levels of RCS close to an emission source are measured but little is known about the wider ambient exposure from industry emissions or natural sources. The aim of this work is to report the RCS concentrations obtained from a variety of ambient environments using a new mobile respirable (PM4) sampler. A mobile battery powered high flow rate (52 L min-1) sampler was developed and evaluated for particulate aerosol sampling employing foams to select the respirable particle size fraction. Sampling was conducted in the United Kingdom at site boundaries surrounding seven urban construction and demolition and five sand quarry sites. These are compared with data from twelve urban aerosol samples and from repeat measurements from a base line study at a single rural site. The 50% particle size penetration (d50) through the foam was 4.3 μm. Over 85% of predict bias values were with ±10% of the respirable convention, which is based on a log normal curve. Results for RCS from all construction and quarry activities are generally low with a 95 th percentile of 11 μg m-3. Eighty percent of results were less than the health benchmark value of 3 μg m-3 used in some states in America for ambient concentrations. The power cutting of brick and the largest demolition activities gave the highest construction levels. Measured urban background RCS levels were typically below 0.3 μg m-3 and the median RCS level, at a rural background location, was 0.02 μg m-3. These reported ambient RCS concentrations may provide useful baseline values to assess the wider impact of fugitive, RCS containing, dust emissions into the wider environment.

Water-quality assessment of south-central Texas : comparison of water quality in surface-water samples collected manually and by automated samplers

Science.gov (United States)

Ging, Patricia B.

1999-01-01

Surface-water sampling protocols of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program specify samples for most properties and constituents to be collected manually in equal-width increments across a stream channel and composited for analysis. Single-point sampling with an automated sampler (autosampler) during storms was proposed in the upper part of the South-Central Texas NAWQA study unit, raising the question of whether property and constituent concentrations from automatically collected samples differ significantly from those in samples collected manually. Statistical (Wilcoxon signed-rank test) analyses of 3 to 16 paired concentrations for each of 26 properties and constituents from water samples collected using both methods at eight sites in the upper part of the study unit indicated that there were no significant differences in concentrations for dissolved constituents, other than calcium and organic carbon.

Multiple spacecraft observations of interplanetary shocks: characteristics of the upstream ulf turbulence

International Nuclear Information System (INIS)

Russell, C.T.; Smith, E.J.; Tsurutani, B.T.; Gosling, J.T.; Bame, S.J.

1982-01-01

All interplanetary shocks observed by ISEE-3 and either ISEE-1 or ISEE-2 or both in 1978 and 1979 are examined for evidence of upstream waves. In order to characterize the properties of these shocks it is necessary to determine accurate shock normals. We invert an overdetermined set of equations to obtain shock normals, velocities and error estimates for all these shocks. Tests of the method indicate it is quite reliable. Using these normals we then calculate the Mach number and angle between the interplanetary magnetic field and the shock normal for each shock. These parameters allow us to separate the upstream waves into two classes: whistler-mode precursors which occur at low Mach numbers and upstream turbulence whose amplitude at Mach numbers greater than 1.5 is controlled by the angle of the field to the shock normal. The former waves are right-hand circularly polarized and quite monochromatic. The latter waves are more linearly polarized and have a broadband featureless spectrum

Biodiesel byproduct bioconversion to rhamnolipids: Upstream aspects.

Science.gov (United States)

Salazar-Bryam, Ana Maria; Lovaglio, Roberta Barros; Contiero, Jonas

2017-06-01

This study focused on two important aspects of the upstream process: the appropriate use of crude glycerol as a low-cost carbon source, and strain selection. The effect of different crude glycerol concentrations on rhamnolipid biosynthesis by two Pseudomonas aeruginosa strains (wild type LBI and mutant LBI 2A1) was studied. Finally, the synthesized rhamnolipids were characterized by mass spectrometry. When both strains were compared, 50 g/L was the most favorable concentration for both, but P. aeruginosa LBI 2A1 showed an increase in rhamnolipid production (2.55 g/L) of 192% over wild type (1.3 g/L). The higher rhamnolipid production could be related to a possible mechanism developed after the mutation process at high antibiotic concentrations. Mass spectrometry confirmed the glycolipid nature of the produced biosurfactant, and the homologue composition showed a wide mixture of mono and di-rhamnolipids. These results show that high glycerol concentrations can inhibit microbial metabolism, due to osmotic stress, leading to a better understanding of glycerol metabolism towards its optimization in fermentation media. Since P. aeruginosa LBI 2A1 showed higher conversion yields than P. aeruginosa LBI, the use of a mutant strain associated with a low cost carbon source might improve biosurfactant biosynthesis, therefore yielding an important upstream improvement.

Multipurpose Sediment Passive Sampler with Improved Tissue Mimicry to Measure the Bioavailable Fraction

Science.gov (United States)

2016-11-01

run by HPLC- DAD . There was a linear relationship between the RDX found in the extract and the amount in the solution (Figures 11 and 12, Raw data can...TNT had occurred in the reaction solution. Moreover, the anion is reactive and can form Meisenheimer complexes with electron rich compounds...The poor recovery was determined to be due to the desorption step since it was found that the samplers efficiently extracted the metals from solution

Torque fluctuations caused by upstream mean flow and turbulence

Science.gov (United States)

Farr, T. D.; Hancock, P. E.

2014-12-01

A series of studies are in progress investigating the effects of turbine-array-wake interactions for a range of atmospheric boundary layer states by means of the EnFlo meteorological wind tunnel. The small, three-blade model wind turbines drive 4-quadrant motor-generators. Only a single turbine in neutral flow is considered here. The motor-generator current can be measured with adequate sensitivity by means of a current sensor allowing the mean and fluctuating torque to be inferred. Spectra of torque fluctuations and streamwise velocity fluctuations ahead of the rotor, between 0.1 and 2 diameters, show that only the large-scale turbulent motions contribute significantly to the torque fluctuations. Time-lagged cross-correlation between upstream velocity and torque fluctuations are largest over the inner part of the blade. They also show the turbulence to be frozen in behaviour over the 2 diameters upstream of the turbine.

Lipid droplet-associated gene expression and chromatin remodelling in LIPASE 5'-upstream region from beginning- to mid-endodormant bud in 'Fuji' apple.

Science.gov (United States)

Saito, Takanori; Wang, Shanshan; Ohkawa, Katsuya; Ohara, Hitoshi; Ikeura, Hiromi; Ogawa, Yukiharu; Kondo, Satoru

2017-11-01

We found that lipid accumulation in the meristem region and the expression of MdLIP2A, which appears to be regulated by chromatin remodeling, coincided with endodormancy induction in the 'Fuji' apple. In deciduous trees, including apples (Malus × domestica Borkh.), lipid accumulation in the meristem region towards endodormancy induction has been thought to be an important process for the acquisition of cold tolerance. In this study, we conducted histological staining of crude lipids in the meristem region of 'Fuji' apples and found that lipid accumulation coincided with endodormancy induction. Since a major component of lipid bodies (triacylglycerol) is esterified fatty acids, we analysed fatty acid-derived volatile compounds and genes encoding fatty acid-modifying enzymes (MdLOX1A and MdHPL2A); the reduction of lipid breakdown also coincided with endodormancy induction. We then characterised the expression patterns of lipid body-regulatory genes MdOLE1 and MdLIP2A during endodormancy induction and found that the expression of MdLIP2A correlated well with lipid accumulation towards endodormancy induction. Based on these results, we conducted chromatin remodelling studies and localized the cis-element in the 5'-upstream region of MdLIP2A to clarify its regulatory mechanism. Finally, we revealed that chromatin was concentrated - 764 to - 862 bp of the 5'-upstream region of MdLIP2A, which harbours the GARE [gibberellin responsive MYB transcription factor binding site] and CArG [MADS-box transcription factor binding site] motifs-meristem development-related protein-binding sites.

Assessing potential effects of highway runoff on receiving-water quality at selected sites in Oregon with the Stochastic Empirical Loading and Dilution Model (SELDM)

Science.gov (United States)

Risley, John C.; Granato, Gregory E.

2014-01-01

In 2012, the U.S. Geological Survey and the Oregon Department of Transportation began a cooperative study to demonstrate use of the Stochastic Empirical Loading and Dilution Model (SELDM) for runoff-quality analyses in Oregon. SELDM can be used to estimate stormflows, constituent concentrations, and loads from the area upstream of a stormflow discharge site, from the site of interest and in the receiving waters downstream of the discharge. SELDM also can be used to assess the potential effectiveness of best management practices (BMP) for mitigating potential effects of runoff in receiving waters. Nominally, SELDM is a highway-runoff model, but it is well suited for analysis of runoff from other land uses as well. This report provides case studies and examples to demonstrate stochastic-runoff modeling concepts and to demonstrate application of the model. Basin characteristics from six Oregon highway study sites were used to demonstrate various applications of the model. The highway catchment and upstream basin drainage areas of these study sites ranged from 3.85 to 11.83 acres and from 0.16 to 6.56 square miles, respectively. The upstream basins of two sites are urbanized, and the remaining four sites are less than 5 percent impervious. SELDM facilitates analysis by providing precipitation, pre-storm streamflow, and other variables by region or from hydrologically similar sites. In Oregon, there can be large variations in precipitation and streamflow among nearby sites. Therefore, spatially interpolated geographic information system data layers containing storm-event precipitation and pre-storm streamflow statistics specific to Oregon were created for the study using Kriging techniques. Concentrations and loads of cadmium, chloride, chromium, copper, iron, lead, nickel, phosphorus, and zinc were simulated at the six Oregon highway study sites by using statistics from sites in other areas of the country. Water‑quality datasets measured at hydrologically similar

A Hybrid MCMC Sampler for Unconditional Quantile Based on Influence Function

Directory of Open Access Journals (Sweden)

El Moctar Laghlal

2018-05-01

Full Text Available In this study, we provide a Bayesian estimation method for the unconditional quantile regression model based on the Re-centered Influence Function (RIF. The method makes use of the dichotomous structure of the RIF and estimates a non-linear probability model by a logistic regression using a Gibbs within a Metropolis-Hastings sampler. This approach performs better in the presence of heavy-tailed distributions. Applied to a nationally-representative household survey, the Senegal Poverty Monitoring Report (2005, the results show that the change in the rate of returns to education across quantiles is substantially lower at the primary level.

UNDERWATER ANALYSIS OF IRRADIATED REACTOR SLUGS FOR Co-60 AND OTHER RADIONUCLIDES AT THE SAVANNAH RIVER SITE

International Nuclear Information System (INIS)

CASELLA, VITO

2004-01-01

Co-60 was produced in the Savannah River Site (SRS) reactors in the 1970s, and the irradiated cobalt reactor slugs were stored in a reactor basin at SRS. Since the activity rates of these slugs were not accurately known, assaying was required. A sodium iodide gamma detector was placed above a specially designed air collimator assembly, so that the slug was eight to nine feet from the detector and was shielded by the basin water. Also, 18 curium sampler slugs, used to produce Cm-244 from Pu-239, were to be disposed of with the cobalt slugs. The curium slugs were also analyzed with a High Purity Germanium (HPGE) detector in an attempt to identify any additional radionuclides produced from the irradiation. Co-60 concentrations were determined for reactor disassembly basin cobalt slugs and the 18 curium sampler slugs. The total Co-60 activity of all of the assayed slugs in this work summed to 31,783 curies on 9/15/03. From the Co-60 concentrations of the curium sampler slugs, the irradiation flux was determined for the known irradiation time. The amounts of Pu-238,-239,-240,-241,-242; Am-241,-243; and Cm-242,-244 produced were then obtained based on the original amount of Pu-239 irradiated

Collisionless shocks and upstream waves and particles: Introductory remarks

International Nuclear Information System (INIS)

Kennel, C.F.

1981-01-01

We discuss more aspects of collisionless shock theory that might be pertinent to the problem of upstream waves and particles. It is hoped that our qualititive remarks may be a useful guide for the general reader as he goes through the detailed papers to come

Research on performance of upstream pumping mechanical seal with different deep spiral groove

International Nuclear Information System (INIS)

Wang, Q; Chen, H L; Liu, T; Liu, Y H; Liu, Z B; Liu, D H

2012-01-01

As one new type of mechanical seal, Upstream Pumping Mechanical Seal has been widely used in fluid machinery. In this paper, structure of spiral groove is innovatively optimized to improve performance of Upstream Pumping Mechanical Seal with Spiral Groove: keeping the dam zone and the weir zone not changed, changing the bottom shape of spiral groove only, substituting different deep spiral groove for equal deep spiral groove. The simulation on Upstream Pumping Mechanical Seal with different deep spiral grooves is done using FVM method. According to calculation, the performances of opening force and pressure distribution on seals face are obtained. Five types of spiral grooves are analyzed, namely equal deep spiral groove, circumferential convergent ladder-like different deep spiral groove, circumferential divergent ladder-like different deep spiral groove, radial convergent ladder-like different deep spiral groove and radial divergent ladder-like different deep spiral groove. This paper works on twenty-five working conditions. The results indicate the performances of circumferential divergent 2-ladder different deep spiral groove are better than the others, with more opening force and better stabilization, while with the same leakage. The outcome provides theoretical support for application of Upstream Pumping Mechanical Seal with circumferential convergent ladder-like different deep spiral groove.

Research on performance of upstream pumping mechanical seal with different deep spiral groove

Science.gov (United States)

Wang, Q.; Chen, H. L.; Liu, T.; Liu, Y. H.; Liu, Z. B.; Liu, D. H.

2012-11-01

As one new type of mechanical seal, Upstream Pumping Mechanical Seal has been widely used in fluid machinery. In this paper, structure of spiral groove is innovatively optimized to improve performance of Upstream Pumping Mechanical Seal with Spiral Groove: keeping the dam zone and the weir zone not changed, changing the bottom shape of spiral groove only, substituting different deep spiral groove for equal deep spiral groove. The simulation on Upstream Pumping Mechanical Seal with different deep spiral grooves is done using FVM method. According to calculation, the performances of opening force and pressure distribution on seals face are obtained. Five types of spiral grooves are analyzed, namely equal deep spiral groove, circumferential convergent ladder-like different deep spiral groove, circumferential divergent ladder-like different deep spiral groove, radial convergent ladder-like different deep spiral groove and radial divergent ladder-like different deep spiral groove. This paper works on twenty-five working conditions. The results indicate the performances of circumferential divergent 2-ladder different deep spiral groove are better than the others, with more opening force and better stabilization, while with the same leakage. The outcome provides theoretical support for application of Upstream Pumping Mechanical Seal with circumferential convergent ladder-like different deep spiral groove.

PM{sub 10} sampler deposited air particulates: Ascertaining uniformity of sample on filter through rotated exposure to radiation

Energy Technology Data Exchange (ETDEWEB)

Owoade, Oyediran K. [Environmental Research Laboratory (ERL), Physics Department, Obafemi Awolowo University, Ile-Ife (Nigeria)]. E-mail: oowoade2001@yahoo.com; Olise, Felix S. [Environmental Research Laboratory (ERL), Physics Department, Obafemi Awolowo University, Ile-Ife (Nigeria); Obioh, Imoh B. [Centre for Energy Research, Development (Cerd), Obafemi Awolowo University, Ile-Ife (Nigeria); Olaniyi, Hezekiah B. [Environmental Research Laboratory (ERL), Physics Department, Obafemi Awolowo University, Ile-Ife (Nigeria); Bolzacchini, Ezio [Universita Milano-Bicocca, Dipartimento di Scienze-Ambientali, Pizza della Scienza, Milan (Italy); Ferrero, Luca [Universita Milano-Bicocca, Dipartimento di Scienze-Ambientali, Pizza della Scienza, Milan (Italy); Perrone, Grazia [Universita Milano-Bicocca, Dipartimento di Scienze-Ambientali, Pizza della Scienza, Milan (Italy)

2006-08-01

For reproducibility of analytical results of samples deposited on filters using PM{sub 10} sampler, homogeneity of the sample on the filter is very important especially when the size of the X-ray beam for the analysis is less than the size of filter. It is against this background that the air particulate samples collected on using PM{sub 10} samplers are analysed to determine the elemental concentrations. Each sample was divided into four quadrants and each was analysed under same conditions to determine if the particles were deposited uniformly over the filter. Each analysis was done using EDXRF technique. The spectrometer consists of four secondary targets, which are automatically switched to in sequence in analysing each sample. The concentration of various elements detected was determined using TURBOQUANT (a brand name for a SPECTRO method which is used for screening analysis). Sixteen elements were detected in every sample. Results show that there was less than 10% deviation in the concentrations in different quadrants. There were a few elements like Ba, Cs, etc., which have deviation greater than 20%. The concentrations of these latter elements were close to detection limits of the spectrometer. We conclude that the analytical result of particulate samples deposited on filters by the PM{sub 10} sampler can be reliable in terms of the homogeneity of the deposition. For such analytes with low concentrations, it would be important that the sampling time be increased to allow for higher mass deposition on the filter.

Modeling the transport of organic chemicals between polyethylene passive samplers and water in finite and infinite bath conditions.

Science.gov (United States)

Tcaciuc, A Patricia; Apell, Jennifer N; Gschwend, Philip M

2015-12-01

Understanding the transfer of chemicals between passive samplers and water is essential for their use as monitoring devices of organic contaminants in surface waters. By applying Fick's second law to diffusion through the polymer and an aqueous boundary layer, the authors derived a mathematical model for the uptake of chemicals into a passive sampler from water, in finite and infinite bath conditions. The finite bath model performed well when applied to laboratory observations of sorption into polyethylene (PE) sheets for various chemicals (polycyclic aromatic hydrocarbons, polychlorinated biphenyls [PCBs], and dichlorodiphenyltrichloroethane [DDT]) and at varying turbulence levels. The authors used the infinite bath model to infer fractional equilibration of PCB and DDT analytes in field-deployed PE, and the results were nearly identical to those obtained using the sampling rate model. However, further comparison of the model and the sampling rate model revealed that the exchange of chemicals was inconsistent with the sampling rate model for partially or fully membrane-controlled transfer, which would be expected in turbulent conditions or when targeting compounds with small polymer diffusivities and small partition coefficients (e.g., phenols, some pesticides, and others). The model can be applied to other polymers besides PE as well as other chemicals and in any transfer regime (membrane, mixed, or water boundary layer-controlled). Lastly, the authors illustrate practical applications of this model such as improving passive sampler design and understanding the kinetics of passive dosing experiments. © 2015 SETAC.

Identification of the first PAR1 deletion encompassing upstream SHOX enhancers in a family with idiopathic short stature.

Science.gov (United States)

Benito-Sanz, Sara; Aza-Carmona, Miriam; Rodríguez-Estevez, Amaya; Rica-Etxebarria, Ixaso; Gracia, Ricardo; Campos-Barros, Angel; Heath, Karen E

2012-01-01

Short stature homeobox-containing gene, MIM 312865 (SHOX) is located within the pseudoautosomal region 1 (PAR1) of the sex chromosomes. Mutations in SHOX or its downstream transcriptional regulatory elements represent the underlying molecular defect in ~60% of Léri-Weill dyschondrosteosis (LWD) and ~5-15% of idiopathic short stature (ISS) patients. Recently, three novel enhancer elements have been identified upstream of SHOX but to date, no PAR1 deletions upstream of SHOX have been observed that only encompass these enhancers in LWD or ISS patients. We set out to search for genetic alterations of the upstream SHOX regulatory elements in 63 LWD and 100 ISS patients with no known alteration in SHOX or the downstream enhancer regions using a specifically designed MLPA assay, which covers the PAR1 upstream of SHOX. An upstream SHOX deletion was identified in an ISS proband and her affected father. The deletion was confirmed and delimited by array-CGH, to extend ~286 kb. The deletion included two of the upstream SHOX enhancers without affecting SHOX. The 13.3-year-old proband had proportionate short stature with normal GH and IGF-I levels. In conclusion, we have identified the first PAR1 deletion encompassing only the upstream SHOX transcription regulatory elements in a family with ISS. The loss of these elements may result in SHOX haploinsufficiency because of decreased SHOX transcription. Therefore, this upstream region should be included in the routine analysis of PAR1 in patients with LWD, LMD and ISS.

Final work plan: Expedited Site Characterization of the IES Industries, Inc., Site at Marshalltown, Iowa. Ames Expedited Site Characterization Project, Version 1.0

Energy Technology Data Exchange (ETDEWEB)

1994-04-04

The overall goal of the Ames Laboratory Expedited Site Characterization (ESC) project is to evaluate and promote both innovative and state-of-the-practice site characterization and/or monitoring technologies. This will be accomplished by fielding both types of technologies together in the context of an expedited site characterization. The first site will be at a former manufactured gas plant (FMGP) in Marshalltown, Iowa. The project will field three areas of technology: geophysical, analytical, and data fusion. Geophysical technologies are designed to understand the subsurface geology to help predict fate and transport of the target contaminants. Analytical technologies/methods are designed to detect and quantify the target contaminants. Data fusion technology consists of software systems designed to rapidly integrate or fuse all site information into a conceptual site model that then becomes the decision making tool for the site team to plan subsequent sampling activity. Not all of the contaminants present can be located at the action level. Polynuclear aromatic hydrocarbons (PAHs) are the signature organics associated with the coal tar activities that took place at the site. As a result, PAHs were selected as the target compounds. Screening analytical instruments and nonintrusive geophysical techniques will be fielded to qualitatively map the spatial contaminant distribution. Soil gas surveys, immunoassay testing (IMA), innovative optical techniques, and passive organic sorbent sensors will be deployed along with the geophysical methods. Gas chromatography/mass spectrometry (GC/MS) instruments and a cone penetrometer system equipped with a laser-induced fluorescence (LIF) probe will quantitatively map the action level edges of the PAH plume(s). Samples will be taken both by the cone penetrometer test system (CPT) and the Geoprobe {reg_sign} sampler system.

A comparison of freshwater mussels and passive samplers as indicators of heavy metal pollution in aquatic systems

DEFF Research Database (Denmark)

Søberg, Laila C.; Vollertsen, Jes; Nielsen, Asbjørn Haaning

2013-01-01

under controlled conditions in order to determine whether either system was capable of functioning as a reliable source of data on aquatic pollution. The laboratory results indicated that mussels are useful in this context. However, passive samplers will require further development to be useful since...

Technical procedures for implementation of background environmental radioactivity site studies, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

International Nuclear Information System (INIS)

1987-09-01

The purpose of this technical procedure is to describe the method for performing field maintenance on low-volume air samplers and the associated topics of personnel and organization, procedure preparation, documentation, and quality assurance. The scope of this procedure includes the maintenance of low-volume air samplers in the field and does not encompass maintenance performed by the manufacturer

Minimizing Characterization - Derived Waste at the Department of Energy Savannah River Site, Aiken, South Carolina

Energy Technology Data Exchange (ETDEWEB)

Van Pelt, R. S.; Amidon, M. B.; Reboul, S. H.

2002-02-25

Environmental restoration activities at the Department of Energy Savannah River Site (SRS) utilize innovative site characterization approaches and technologies that minimize waste generation. Characterization is typically conducted in phases, first by collecting large quantities of inexpensive data, followed by targeted minimally invasive drilling to collect depth-discrete soil/groundwater data, and concluded with the installation of permanent multi-level groundwater monitoring wells. Waste-reducing characterization methods utilize non-traditional drilling practices (sonic drilling), minimally intrusive (geoprobe, cone penetrometer) and non-intrusive (3-D seismic, ground penetration radar, aerial monitoring) investigative tools. Various types of sensor probes (moisture sensors, gamma spectroscopy, Raman spectroscopy, laser induced and X-ray fluorescence) and hydrophobic membranes (FLUTe) are used in conjunction with depth-discrete sampling techniques to obtain high-resolution 3-D plume profiles. Groundwater monitoring (short/long-term) approaches utilize multi-level sampling technologies (Strata-Sampler, Cone-Sipper, Solinst Waterloo, Westbay) and low-cost diffusion samplers for seepline/surface water sampling. Upon collection of soil and groundwater data, information is portrayed in a Geographic Information Systems (GIS) format for interpretation and planning purposes. At the SRS, the use of non-traditional drilling methods and minimally/non intrusive investigation approaches along with in-situ sampling methods has minimized waste generation and improved the effectiveness and efficiency of characterization activities.

Minimizing Characterization - Derived Waste at the Department of Energy Savannah River Site, Aiken, South Carolina

International Nuclear Information System (INIS)

Van Pelt, R. S.; Amidon, M. B.; Reboul, S. H.

2002-01-01

Environmental restoration activities at the Department of Energy Savannah River Site (SRS) utilize innovative site characterization approaches and technologies that minimize waste generation. Characterization is typically conducted in phases, first by collecting large quantities of inexpensive data, followed by targeted minimally invasive drilling to collect depth-discrete soil/groundwater data, and concluded with the installation of permanent multi-level groundwater monitoring wells. Waste-reducing characterization methods utilize non-traditional drilling practices (sonic drilling), minimally intrusive (geoprobe, cone penetrometer) and non-intrusive (3-D seismic, ground penetration radar, aerial monitoring) investigative tools. Various types of sensor probes (moisture sensors, gamma spectroscopy, Raman spectroscopy, laser induced and X-ray fluorescence) and hydrophobic membranes (FLUTe) are used in conjunction with depth-discrete sampling techniques to obtain high-resolution 3-D plume profiles. Groundwater monitoring (short/long-term) approaches utilize multi-level sampling technologies (Strata-Sampler, Cone-Sipper, Solinst Waterloo, Westbay) and low-cost diffusion samplers for seepline/surface water sampling. Upon collection of soil and groundwater data, information is portrayed in a Geographic Information Systems (GIS) format for interpretation and planning purposes. At the SRS, the use of non-traditional drilling methods and minimally/non intrusive investigation approaches along with in-situ sampling methods has minimized waste generation and improved the effectiveness and efficiency of characterization activities

Biodiesel byproduct bioconversion to rhamnolipids: Upstream aspects

OpenAIRE

Salazar-Bryam, Ana Maria; Lovaglio, Roberta Barros; Contiero, Jonas

2017-01-01

This study focused on two important aspects of the upstream process: the appropriate use of crude glycerol as a low-cost carbon source, and strain selection. The effect of different crude glycerol concentrations on rhamnolipid biosynthesis by two Pseudomonas aeruginosa strains (wild type LBI and mutant LBI 2A1) was studied. Finally, the synthesized rhamnolipids were characterized by mass spectrometry. When both strains were compared, 50 g/L was the most favorable concentration for both, but P...

Employee assistance programs in the upstream petroleum industry

International Nuclear Information System (INIS)

Crutcher, R.A.; Yip, R.Y.; Young, M.R.

1991-01-01

This paper is a descriptive overview of Employee Assistance Programs (EAPs) in the upstream Canadian petroleum industry. The authors review current EAP models within the occupational health setting and the Canadian health care context. This article also explores the challenging issues of EAP's emergent functions in workplace substance abuse programs, its changing role in organizational effectiveness and its professional identity

A Tourist-like MITE insertion in the upstream region of the BnFLC.A10 gene is associated with vernalization requirement in rapeseed (Brassica napus L.).

Science.gov (United States)

Hou, Jinna; Long, Yan; Raman, Harsh; Zou, Xiaoxiao; Wang, Jing; Dai, Shutao; Xiao, Qinqin; Li, Cong; Fan, Longjiang; Liu, Bin; Meng, Jinling

2012-12-15

Rapeseed (Brassica napus L.) has spring and winter genotypes adapted to different growing seasons. Winter genotypes do not flower before the onset of winter, thus leading to a longer vegetative growth period that promotes the accumulation and allocation of more resources to seed production. The development of winter genotypes enabled the rapeseed to spread rapidly from southern to northern Europe and other temperate regions of the world. The molecular basis underlying the evolutionary transition from spring- to winter- type rapeseed is not known, however, and needs to be elucidated. We fine-mapped the spring environment specific quantitative trait locus (QTL) for flowering time, qFT10-4,in a doubled haploid (DH) mapping population of rapeseed derived from a cross between Tapidor (winter-type) and Ningyou7 (semi-winter) and delimited the qFT10-4 to an 80-kb region on chromosome A10 of B. napus. The BnFLC.A10 gene, an ortholog of FLOWERING LOCUS C (FLC) in Arabidopsis, was cloned from the QTL. We identified 12 polymorphic sites between BnFLC.A10 parental alleles of the TN-DH population in the upstream region and in intron 1. Expression of both BnFLC.A10 alleles decreased during vernalization, but decreased more slowly in the winter parent Tapidor. Haplotyping and association analysis showed that one of the polymorphic sites upstream of BnFLC.A10 is strongly associated with the vernalization requirement of rapeseed (r2 = 0.93, χ2 = 0.50). This polymorphic site is derived from a Tourist-like miniature inverted-repeat transposable element (MITE) insertion/deletion in the upstream region of BnFLC.A10. The MITE sequence was not present in the BnFLC.A10 gene in spring-type rapeseed, nor in ancestral 'A' genome species B. rapa genotypes. Our results suggest that the insertion may have occurred in winter rapeseed after B. napus speciation. Our findings strongly suggest that (i) BnFLC.A10 is the gene underlying qFT10-4, the QTL for phenotypic diversity of flowering time in

Probabilistic Magnetotelluric Inversion with Adaptive Regularisation Using the No-U-Turns Sampler

Science.gov (United States)

Conway, Dennis; Simpson, Janelle; Didana, Yohannes; Rugari, Joseph; Heinson, Graham

2018-04-01

We present the first inversion of magnetotelluric (MT) data using a Hamiltonian Monte Carlo algorithm. The inversion of MT data is an underdetermined problem which leads to an ensemble of feasible models for a given dataset. A standard approach in MT inversion is to perform a deterministic search for the single solution which is maximally smooth for a given data-fit threshold. An alternative approach is to use Markov Chain Monte Carlo (MCMC) methods, which have been used in MT inversion to explore the entire solution space and produce a suite of likely models. This approach has the advantage of assigning confidence to resistivity models, leading to better geological interpretations. Recent advances in MCMC techniques include the No-U-Turns Sampler (NUTS), an efficient and rapidly converging method which is based on Hamiltonian Monte Carlo. We have implemented a 1D MT inversion which uses the NUTS algorithm. Our model includes a fixed number of layers of variable thickness and resistivity, as well as probabilistic smoothing constraints which allow sharp and smooth transitions. We present the results of a synthetic study and show the accuracy of the technique, as well as the fast convergence, independence of starting models, and sampling efficiency. Finally, we test our technique on MT data collected from a site in Boulia, Queensland, Australia to show its utility in geological interpretation and ability to provide probabilistic estimates of features such as depth to basement.

Coral record of variability in the upstream Kuroshio Current during 1953-2004

Science.gov (United States)

Li, Xiaohua; Liu, Yi; Hsin, Yi-Chia; Liu, Weiguo; Shi, Zhengguo; Chiang, Hong-Wei; Shen, Chuan-Chou

2017-08-01

The Kuroshio Current (KC), one of the most important western boundary currents in the North Pacific Ocean, strongly affects regional hydroclimate in East Asia and upper ocean thermal structure. Limited by few on-site observations, the responses of the KC to regional and remote climate forcings are still poorly understood. Here we use monthly coral δ18O data to reconstruct a KC transport record with annual to interannual resolution for the interval 1953-2004. The field site is located in southern Taiwan on the western flank of the upstream KC. Increased (reduced) KC transport would generate strong (weak) upwelling, resulting in relatively high (low) local coral δ18O. The upstream KC transport and downstream transport, off Tatsukushi Bay, Japan, covary on interannual and decadal time scales. This suggests common forcings, such as meridional drift of the North Equatorial Current bifurcation, or zonal climatic oscillations in the Pacific. The intensities of KC transport off southeastern and northeastern Taiwan are in phase before 1990 and antiphase after 1990. This difference may be due to a poleward shift of the subtropical western boundary current as a response to global warming.Plain Language SummaryThe connection between climate and oceanic circulation has long been recognized, particularly with regard to western boundary currents such as the Gulf Stream and the Kuroshio Current (KC). These systems play a crucial role in transferring solar energy from the subtropical regions to the poles. As we begin to experience the impacts of global climate change, it is critical that we understand the affect global change has on variability leading to significant changes in the structure and heat transport of such currents. Current knowledge of the KC is limited to observations over individual 10 year periods or to paleorecords of very low resolution (one sample per roughly 1000 years). Neither data set allows for a detailed understanding of the natural variability of the KC

Geological nominations at UNESCO World Heritage, an upstream struggle

Science.gov (United States)

Olive-Garcia, Cécile; van Wyk de Vries, Benjamin

2017-04-01

Using my 10 years experience in setting up and defending a UNESCO world Heritage Geological nomination, this presentation aims to give a personal insight into this international process and the differential use of science, subjective perception (aesthetic and 'naturality'), and politics. At this point in the process, new protocols have been tested in order to improve the dialogue, accountability and transparency between the different stake-holders. These are, the State parties, the IUCN, the scientific community, and UNESCO itself. Our proposal is the Chaîne des Puys-Limagne fault ensemble, which combines tectonic, geomorphological evolution and volcanology. The project's essence is a conjunction of inseparable geological features and processes, set in the context of plate tectonics. This very unicit yof diverse forms and processes creates the value of the site. However, it is just this that has caused a problem, as the advisory body has a categorical approach of nominations that separates items to assess them in an unconnected manner.From the start we proposed a combined approach, where a property is seen in its entirety, and the constituent elements seen as interlinked elements reflecting the joint underlying phenomena. At this point, our project has received the first ever open review by an independent technical mission (jointly set up by IUCN, UNESCO and the State party). The subsequent report was broadly supportive of the project's approach and of the value of the ensemble of features. The UNESCO committee in 2016, re-referred the nomination, acknowledging the potential Outstanding Universal Value of the site and requesting the parties to continue the upstream process (e.g. collaborative work), notably on the recommendations and conclusions of the Independent Technical mission report. Meetings are continuing, and I shall provide you with the hot-off-the-press news as this ground breaking nomination progresses.

Biodiesel byproduct bioconversion to rhamnolipids: Upstream aspects

Directory of Open Access Journals (Sweden)

Ana Maria Salazar-Bryam

2017-06-01

Full Text Available This study focused on two important aspects of the upstream process: the appropriate use of crude glycerol as a low-cost carbon source, and strain selection. The effect of different crude glycerol concentrations on rhamnolipid biosynthesis by two Pseudomonas aeruginosa strains (wild type LBI and mutant LBI 2A1 was studied. Finally, the synthesized rhamnolipids were characterized by mass spectrometry. When both strains were compared, 50 g/L was the most favorable concentration for both, but P. aeruginosa LBI 2A1 showed an increase in rhamnolipid production (2.55 g/L of 192% over wild type (1.3 g/L. The higher rhamnolipid production could be related to a possible mechanism developed after the mutation process at high antibiotic concentrations. Mass spectrometry confirmed the glycolipid nature of the produced biosurfactant, and the homologue composition showed a wide mixture of mono and di-rhamnolipids. These results show that high glycerol concentrations can inhibit microbial metabolism, due to osmotic stress, leading to a better understanding of glycerol metabolism towards its optimization in fermentation media. Since P. aeruginosa LBI 2A1 showed higher conversion yields than P. aeruginosa LBI, the use of a mutant strain associated with a low cost carbon source might improve biosurfactant biosynthesis, therefore yielding an important upstream improvement. Keywords: Biotechnology, Microbiology

Radiological impact of surface water and sediment near uranium mining sites.

Science.gov (United States)

Ivanova, K; Stojanovska, Z; Badulin, V; Kunovska, B; Yovcheva, M

2015-12-01

The aim of this study is to assess the radiological impact of surface water and sediment around uranium mining sites 20 years after their closing. The areas under observations are 31 former classical underground uranium mining and exploratory sites in Bulgaria, named as objects. The extraction and processing of uranium ores in the Republic of Bulgaria were ended in 1992. To assess the radiological impact of radionuclides field expeditions were performed to sample water and bottom sediment. The migration of uranium through surface water was examined as one of the major pathways for contamination spread. The range of uranium concentration in water flowing from the mining sites was from 0.012 to 6.8 mgU l(-1) with a geometric mean of 0.192 mgU l(-1). The uranium concentrations in water downstream the mining sites were approximately 3 times higher than the background value (upstream). The concentrations of Unat, (226)Ra, (210)Pb, and (232)Th in the sediment of downstream river were higher than those upstream by 3.4, 2.6, 2, and 1.7 times, respectively. The distribution coefficient of uranium reflects its high mobility in most of the sites. In order to evaluate the impact on people as well as site prioritization for more detailed assessment and water management, screening dose assessments were done.

Increased risk of oesophageal adenocarcinoma among upstream petroleum workers

Science.gov (United States)

Kirkeleit, Jorunn; Riise, Trond; Bjørge, Tone; Moen, Bente E; Bråtveit, Magne; Christiani, David C

2013-01-01

Objectives To investigate cancer risk, particularly oesophageal cancer, among male upstream petroleum workers offshore potentially exposed to various carcinogenic agents. Methods Using the Norwegian Registry of Employers and Employees, 24 765 male offshore workers registered from 1981 to 2003 was compared with 283 002 male referents from the general working population matched by age and community of residence. The historical cohort was linked to the Cancer Registry of Norway and the Norwegian Cause of Death Registry. Results Male offshore workers had excess risk of oesophageal cancer (RR 2.6, 95% CI 1.4 to 4.8) compared with the reference population. Only the adenocarcinoma type had a significantly increased risk (RR 2.7, 95% CI 1.0 to 7.0), mainly because of an increased risk among upstream operators (RR 4.3, 95% CI 1.3 to 14.5). Upstream operators did not have significant excess of respiratory system or colon cancer or mortality from any other lifestyle-related diseases investigated. Conclusion We found a fourfold excess risk of oesophageal adenocarcinoma among male workers assumed to have had the most extensive contact with crude oil. Due to the small number of cases, and a lack of detailed data on occupational exposure and lifestyle factors associated with oesophageal adenocarcinoma, the results must be interpreted with caution. Nevertheless, given the low risk of lifestyle-related cancers and causes of death in this working group, the results add to the observations in other low-powered studies on oesophageal cancer, further suggesting that factors related to the petroleum stream or carcinogenic agents used in the production process might be associated with risk of oesophageal adenocarcinoma. PMID:19858535

Gibbs Sampler-Based λ-Dynamics and Rao-Blackwell Estimator for Alchemical Free Energy Calculation.

Science.gov (United States)

Ding, Xinqiang; Vilseck, Jonah Z; Hayes, Ryan L; Brooks, Charles L

2017-06-13

λ-dynamics is a generalized ensemble method for alchemical free energy calculations. In traditional λ-dynamics, the alchemical switch variable λ is treated as a continuous variable ranging from 0 to 1 and an empirical estimator is utilized to approximate the free energy. In the present article, we describe an alternative formulation of λ-dynamics that utilizes the Gibbs sampler framework, which we call Gibbs sampler-based λ-dynamics (GSLD). GSLD, like traditional λ-dynamics, can be readily extended to calculate free energy differences between multiple ligands in one simulation. We also introduce a new free energy estimator, the Rao-Blackwell estimator (RBE), for use in conjunction with GSLD. Compared with the current empirical estimator, the advantage of RBE is that RBE is an unbiased estimator and its variance is usually smaller than the current empirical estimator. We also show that the multistate Bennett acceptance ratio equation or the unbinned weighted histogram analysis method equation can be derived using the RBE. We illustrate the use and performance of this new free energy computational framework by application to a simple harmonic system as well as relevant calculations of small molecule relative free energies of solvation and binding to a protein receptor. Our findings demonstrate consistent and improved performance compared with conventional alchemical free energy methods.

Functions and requirements for the INEL light duty utility arm sampler end effector

International Nuclear Information System (INIS)

Pace, D.P.; Barnes, G.E.

1995-02-01

This sampler end effector system functions and requirements document defines the system functions that the end effector must perform as well as the requirements the design must meet. Safety, quality assurance, operations, environmental conditions, and regulatory requirements have been considered. The main purpose of this document is to provide a basis for the end effector engineering, design, and fabrication activities. The document shall be the living reference document to initiate the development activities and will be updated as system technologies are finalized

Beehold : the colony of the honeybee (Apis mellifera L) as a bio-sampler for pollutants and plant pathogens

NARCIS (Netherlands)

Steen, van der J.J.M.

2016-01-01

Bio-sampling is a function of bio-indication. Bio-indication with honeybee colonies (Apis mellifera L) is where the research fields of environmental technology and apiculture overlap. The honeybees are samplers of the environment by collecting unintentionally and simultaneously, along

Experimental investigation on the wake interference among wind turbines sited in atmospheric boundary layer winds

Institute of Scientific and Technical Information of China (English)

W. Tian; A. Ozbay; X. D. Wang; H.Hu

2017-01-01

We examined experimentally the effects of incom-ing surface wind on the turbine wake and the wake interfer-ence among upstream and downstream wind turbines sited in atmospheric boundary layer (ABL) winds. The experi-ment was conducted in a large-scale ABL wind tunnel with scaled wind turbine models mounted in different incom-ing surface winds simulating the ABL winds over typical offshore/onshore wind farms. Power outputs and dynamic loadings acting on the turbine models and the wake flow char-acteristics behind the turbine models were quantified. The results revealed that the incoming surface winds significantly affect the turbine wake characteristics and wake interference between the upstream and downstream turbines. The velocity deficits in the turbine wakes recover faster in the incoming surface winds with relatively high turbulence levels. Varia-tions of the power outputs and dynamic wind loadings acting on the downstream turbines sited in the wakes of upstream turbines are correlated well with the turbine wakes charac-teristics. At the same downstream locations, the downstream turbines have higher power outputs and experience greater static and fatigue loadings in the inflow with relatively high turbulence level, suggesting a smaller effect of wake inter-ference for the turbines sited in onshore wind farms.

Wind Predictions Upstream Wind Turbines from a LiDAR Database

Directory of Open Access Journals (Sweden)

Soledad Le Clainche

2018-03-01

Full Text Available This article presents a new method to predict the wind velocity upstream a horizontal axis wind turbine from a set of light detection and ranging (LiDAR measurements. The method uses higher order dynamic mode decomposition (HODMD to construct a reduced order model (ROM that can be extrapolated in space. LiDAR measurements have been carried out upstream a wind turbine at six different planes perpendicular to the wind turbine axis. This new HODMD-based ROM predicts with high accuracy the wind velocity during a timespan of 24 h in a plane of measurements that is more than 225 m far away from the wind turbine. Moreover, the technique introduced is general and obtained with an almost negligible computational cost. This fact makes it possible to extend its application to both vertical axis wind turbines and real-time operation.

Willingness of upstream and downstream resource managers to engage in compensation schemes for environmental services

Directory of Open Access Journals (Sweden)

Chapika Sangkapitux

2009-04-01

Full Text Available Providing compensation for agricultural conservation practices adopted by upstream farmers is still an alien concept in the Thai political context. The governance of common-pool natural resources, such as forest and water, has traditionally been under the control of powerful government line agencies, while the contribution of local communities to natural resource conservation have been hardly recognized by policy-makers. Drawing on a case study in Mae Sa watershed, Chiang Mai province, northern Thailand, this paper discusses the potential of developing compensation schemes in a socio-political context where upland farmers – mostly belonging to ethnic minority groups – tend to be considered a threat to the natural resource base rather than providers of environmental services. Based on data obtained from 371 households in the upstream communities and 151 households in the downstream communities of the watershed, upstream resource managers’ willingness to accept compensation for the conservation measures and downstream resource managers’ willingness to pay for water resource improvements were estimated through the use of choice experiments. Results from the study suggest that downstream resource managers would be willing to provide on average nearly 1% of their annual income for a substantial improvement of the quantity and quality of water resources, which could be achieved by compensating upstream farmers’ change of their agricultural systems towards more environment-friendly practices. Both willingness to pay of downstream respondents and willingness of upstream resource managers to accept compensation were positively correlated with age, education, participation in environmental conservation activities and previous experiences with droughts and/or erosion. The paper concludes that there is a clear potential for establishing compensation schemes for provision of environmental services in northern Thai watersheds. The important policy

Concentration and movement of neonicotinoids as particulate matter downwind during agricultural practices using air samplers in southwestern Ontario, Canada.

Science.gov (United States)

Forero, Luis Gabriel; Limay-Rios, Victor; Xue, Yingen; Schaafsma, Arthur

2017-12-01

Atmospheric emissions of neonicotinoid seed treatment insecticides as particulate matter in field crops occur mainly for two reasons: 1) due to abraded dust of treated seed generated during planting using vacuum planters, and 2) as a result of disturbances (tillage or wind events) in the surface of parental soils which release wind erodible soil-bound residues. In the present study, concentration and movement of neonicotinoids as particulate matter were quantified under real conditions using passive and active air samplers. Average neonicotinoid concentrations in Total Suspended Particulate (TSP) using passive samplers were 0.48 ng/cm 2 , trace, trace (LOD 0.80 and 0.04 ng/cm 2 for clothianidin and thiamethoxam, respectively), and using active samplers 16.22, 1.91 and 0.61 ng/m 3 during planting, tillage and wind events, respectively. There was a difference between events on total neonicotinoid concentration collected in particulate matter using either passive or active sampling. Distance of sampling from the source field during planting of treated seed had an effect on total neonicotinoid air concentration. However, during tillage distance did not present an effect on measured concentrations. Using hypothetical scenarios, values of contact exposure for a honey bee were estimated to be in the range from 1.1% to 36.4% of the reference contact LD 50 value of clothianidin of 44 ng/bee. Copyright © 2017 Elsevier Ltd. All rights reserved.

Canada's upstream petroleum industry : 1997 perspective

International Nuclear Information System (INIS)

1997-06-01

A review of the trends and activities in the upstream petroleum industry during 1996 were presented, emphasizing the significance of the industry' contribution to Canada's economy. Among the areas included were highlights of Canada's hydrocarbon reserves, conventional production, frontier production, and non-conventional (oil sands) production. New market opportunities and activities in the pipeline transportation sector were also discussed. Environmental issues including health and safety received due attention. In this regard, the industry's efforts to work with government and other stakeholders to ensure that requirements for land use are balanced with the need to protect wilderness and wildlife habitat, received special mention. 16 figs

How downstream sub-basins depend on upstream inflows to avoid scarcity: typology and global analysis of transboundary rivers

Science.gov (United States)

Munia, Hafsa Ahmed; Guillaume, Joseph H. A.; Mirumachi, Naho; Wada, Yoshihide; Kummu, Matti

2018-05-01

Countries sharing river basins are often dependent upon water originating outside their boundaries; meaning that without that upstream water, water scarcity may occur with flow-on implications for water use and management. We develop a formalisation of this concept drawing on ideas about the transition between regimes from resilience literature, using water stress and water shortage as indicators of water scarcity. In our analytical framework, dependency occurs if water from upstream is needed to avoid scarcity. This can be diagnosed by comparing different types of water availability on which a sub-basin relies, in particular local runoff and upstream inflows. At the same time, possible upstream water withdrawals reduce available water downstream, influencing the latter water availability. By developing a framework of scarcity and dependency, we contribute to the understanding of transitions between system regimes. We apply our analytical framework to global transboundary river basins at the scale of sub-basin areas (SBAs). Our results show that 1175 million people live under water stress (42 % of the total transboundary population). Surprisingly, the majority (1150 million) of these currently suffer from stress only due to their own excessive water use and possible water from upstream does not have impact on the stress status - i.e. they are not yet dependent on upstream water to avoid stress - but could still impact on the intensity of the stress. At the same time, 386 million people (14 %) live in SBAs that can avoid stress owing to available water from upstream and have thus upstream dependency. In the case of water shortage, 306 million people (11 %) live in SBAs dependent on upstream water to avoid possible shortage. The identification of transitions between system regimes sheds light on how SBAs may be affected in the future, potentially contributing to further refined analysis of inter- and intrabasin hydro-political power relations and strategic planning

High-level core sample x-ray imaging at the Hanford Site

International Nuclear Information System (INIS)

Weber, J.R.; Keve, J.K.

1995-10-01

Waste tank sampling of radioactive high-level waste is required for continued operations, waste characterization, and site safety. Hanford Site tank farms consist of 28 double-shell and 149 single-shell underground storage tanks. The single shell tanks are out-of-service an no longer receive liquid waste. Core samples of salt cake and sludge waste are remotely obtained using truck-mounted, core drill platforms. Samples are recovered from tanks through a 2.25 inch (in.) drill pipe in 26-in. steel tubes, 1.5 in. diameter. Drilling parameters vary with different waste types. Because sample recovery has been marginal an inadequate at times, a system was needed to provide drill truck operators with ''real-time feedback'' about the physical condition of the sample and the percent recovery, prior to making nuclear assay measurements and characterizations at the analytical laboratory. The Westinghouse Hanford Company conducted proof-of-principal radiographic testing to verify the feasibility of a proposed imaging system. Tests were conducted using an iridium 192 radiography source to determine the effects of high radiation on image quality. The tests concluded that samplers with a dose rate in excess of 5000 R/hr could be imaged with only a slight loss of image quality and samples less than 1000 R/hr have virtually no effect on image quality. The Mobile Core Sample X-Ray Examination System, a portable vendor-engineered assembly, has components uniquely configured to produce a real-time radiographic system suitable for safely examining radioactive tank core segments collected at the Hanford Site. The radiographic region of interest extends from the bottom (valve) of the sampler upward 19 to 20 in. The purpose of the Mobile Core Sample X-Ray Examination System is to examine the physical contents of core samples after removal from the tank and prior to placement in an onsite transfer cask

Promoter proximal polyadenylation sites reduce transcription activity

DEFF Research Database (Denmark)

Andersen, Pia Kjølhede; Lykke-Andersen, Søren; Jensen, Torben Heick

2012-01-01

Gene expression relies on the functional communication between mRNA processing and transcription. We previously described the negative impact of a point-mutated splice donor (SD) site on transcription. Here we demonstrate that this mutation activates an upstream cryptic polyadenylation (CpA) site......, which in turn causes reduced transcription. Functional depletion of U1 snRNP in the context of the wild-type SD triggers the same CpA event accompanied by decreased RNA levels. Thus, in accordance with recent findings, U1 snRNP can shield premature pA sites. The negative impact of unshielded pA sites...... on transcription requires promoter proximity, as demonstrated using artificial constructs and supported by a genome-wide data set. Importantly, transcription down-regulation can be recapitulated in a gene context devoid of splice sites by placing a functional bona fide pA site/transcription terminator within ∼500...

Environmental regulatory framework for the upstream petroleum industry

International Nuclear Information System (INIS)

1996-01-01

In order to provide its member companies with a useful reference document in environmental analysis and compliance, CAPP compiled a list of Canadian legislation, regulations and guidelines which relate to the upstream petroleum industry. Text of all federal, Alberta, British Columbia and Saskatchewan legislation, regulations, guidelines and related documents were provided. Pending legislation, regulations and government policy have been identified. Annual updates will be provided to all subscribers

Plutonium-aerosol emission rates and human pulmonary deposition calculations for Nuclear Site 201, Nevada Test Site

International Nuclear Information System (INIS)

Shinn, J.H.; Homan, D.N.

1982-01-01

This study determined the plutonium-aerosol fluxes from the soil to quantify (1) the extent of potential human exposure by deep-lung retention of alpha-emitting particles; (2) the source term should there be any significant, long-term, transport of plutonium aerosols; and (3) the resuspension factor and rate so that, for the first time at any nuclear site, one may calculate how long it will take for wind erosion to carry away a significant amount of the contaminated soil. High-volume air samplers and cascade impactors were used to characterize the plutonium aerosols. Meteorological flux-profile methods were used to calculate dust and plutonium aerosol emission rates. A floorless wind tunnel (10-m long) was used to examine resuspension under steady-state, high wind speed. The resuspension factor was two orders of magnitude lower than the other comparable sites at NTS and elsewhere, and the average resuspension rate of 5.3 x 10 -8 /d was also very low, so that the half-time for resuspension by wind erosion was about 36,000 y

Emerging and Legacy Contaminants in The Foodweb in The Lower Columbia River: USGS ConHab Project

Science.gov (United States)

Nilsen, E. B.; Alvarez, D.; Counihan, T.; Elias, E.; Gelfenbaum, G. R.; Hardiman, J.; Jenkins, J.; Mesa, M.; Morace, J.; Patino, R.; Torres, L.; Waite, I.; Zaugg, S.

2012-12-01

An interdisciplinary study, USGS Columbia River Contaminants and Habitat Characterization (ConHab) project, investigates transport pathways, chemical fate, and effects of polybrominated diphenyl ethers (PBDEs) and other endocrine disrupting chemicals (EDCs) in aquatic media and the foodweb in the lower Columbia River, Oregon and Washington. Polar organic chemical integrative samplers (POCIS) and semipermeable membrane devices (SPMDs) were co-deployed at each of 10 sites in 2008 to provide a measure of the dissolved concentrations of select PBDEs, chlorinated pesticides, and other EDCs. PBDE-47 was the most prevalent of the PBDEs detected. Numerous organochlorine pesticides, both banned and current-use, including hexachlorobenzene, pentachloroanisole, dichlorodiphenyltrichloroethane (DDT) and its degradates, chlorpyrifos, endosulfan, and the endosulfan degradation products, were measured at each site. EDCs commonly detected included a series of polycyclic aromatic hydrocarbons (PAHs), fragrances (galaxolide), pesticides (chlorpyrifos and atrazine), plasticizers (phthalates), and flame retardants (phosphates). The downstream sites tended to have the highest concentrations of contaminants in the lower Columbia River. In 2009 and 2010 passive samplers were deployed and resident largescale suckers (Catostomus macrocheilus) and surface bed sediments were collected at three of the original sites representing a gradient of exposure based on 2008 results. Brain, fillet, liver, stomach, and gonad tissues were analyzed. Chemical concentrations were highest in livers, followed by brain, stomach, gonad, and, lastly, fillet. Concentrations of halogenated compounds in tissue samples ranged from PBDE-100 > PBDE-154 > PBDE-153. Concentrations in tissues and in sediments increased moving downstream from Skamania, WA to Columbia City, OR to Longview, WA. Preliminary biomarker results indicate that fish at the downstream sites experience greater stress relative to the upstream site

Effects on the upstream flood inundation caused from the operation of Chao Phraya Dam

Directory of Open Access Journals (Sweden)

Sutham Visutimeteegorn

2007-11-01

Full Text Available During the flooding events, the operation of Chao Phraya Dam to control downstream water discharge is one of the causes of the inundation occuring over the upstream area. The purposes of this research are to study the effects of the operation of Chao Phraya Dam upon the upstream flood inundation and to find out the new measures of the flood mitigation in the upstream areas of Chao Phraya Dam by using a hydrodynamic model. The results show that Manning's n in the Chao Phraya River and its tributaries is 0.030-0.035 in the main channels and 0.050-0.070 in the flood plain areas. The backwater due to the operation of the Chao Praya dam affects as far as 110 kilometers upstream. New methods of water diversion can mitigate the flood inundation without the effect on the floating rice fields. The construction of reservoirs in the Upper Sakaekang River Basin and the Upper Yom River Basin will mitigate the flood not only in their own basins but also in the Lower Chao Phraya River Basin. The coordinated operation of the Chao Phraya Dam, the regulators and the upper basin reservoirs will efficiently mitigate the flood inundation.

Radiotracer studies in cavernous marble at Kamathikhairy Dam site, Pench Project (Maharashtra)

International Nuclear Information System (INIS)

Nath, Ravendra; Mahajan, N.M.; Vaidya, S.D.

1982-01-01

Radiotracer studies with tritiated water at Pench Project site conclusively proved that the cavernous marble upstream of the saddle dam is continuous with the marble occuring near the spillway portion of the main dam and that there is fast subterranean flow of water through the cavernous marble here. It is also established that this marble band upstream of the dam is interconnected with the marble band occuring in the vicinity of Pali village about 3 km downstream of the dam. Though big unclogged subterranean channels do not seem to exist in this region, which might have resulted in heavy leakage from the impounded reservoir, yet the possibility of some leakage of the water through the cavernous marble cannot be ruled out, due to the interconnection of the marble occuring upstream of the dam with the downstream marble band. (author)

Observations of two distinct populations of bow shock ions in the upstream solar wind

International Nuclear Information System (INIS)

Gosling, J.T.; Asbridge, J.; Bame, S.J.; Paschmann, G.; Sckopke, N.

1978-01-01

Observations upstream of the earth's bow shock with the LASL/MPI fast plasma experiments on ISEE 1 and 2 reveal the presence of two distinct and mutually exclusive populations of low energy (< or approx. =40keV) ions apparently accelerated at the bow shock. The first of these, the ''reflected'' population, is characterized by 1) sharply peaked spectra seldom extending much above approx. 10 keV/ion and 2) relatively collimated flow coming from the direction of the shock. On the other hand, the ''diffuse'' ions are distinguished by relatively flat energy spectra above approx. 10 keV and broad angular distributions. They are by far the most commonly observed upstream ion event. A close causal association is suggested between the diffuse ion population in the upstream solar wind and energetic plasma ions observed within the magnetosheath

MESSENGER Magnetic Field Observations of Upstream Ultra-Low Frequency Waves at Mercury

Science.gov (United States)

Le, G.; Chi, P. J.; Boardsen, S.; Blanco-Cano, X.; Anderosn, B. J.; Korth, H.

2012-01-01

The region upstream from a planetary bow shock is a natural plasma laboratory containing a variety of wave particle phenomena. The study of foreshocks other than the Earth's is important for extending our understanding of collisionless shocks and foreshock physics since the bow shock strength varies with heliocentric distance from the Sun, and the sizes of the bow shocks are different at different planets. The Mercury's bow shock is unique in our solar system as it is produced by low Mach number solar wind blowing over a small magnetized body with a predominately radial interplanetary magnetic field. Previous observations of Mercury upstream ultra-low frequency (ULF) waves came exclusively from two Mercury flybys of Mariner 10. The MESSENGER orbiter data enable us to study of upstream waves in the Mercury's foreshock in depth. This paper reports an overview of upstream ULF waves in the Mercury's foreshock using high-time resolution magnetic field data, 20 samples per second, from the MESSENGER spacecraft. The most common foreshock waves have frequencies near 2 Hz, with properties similar to the I-Hz waves in the Earth's foreshock. They are present in both the flyby data and in every orbit of the orbital data we have surveyed. The most common wave phenomenon in the Earth's foreshock is the large-amplitude 30-s waves, but similar waves at Mercury have frequencies at near 0.1 Hz and occur only sporadically with short durations (a few wave cycles). Superposed on the "30-s" waves, there are spectral peaks at near 0.6 Hz, not reported previously in Mariner 10 data. We will discuss wave properties and their occurrence characteristics in this paper.

EMMPRIN, an upstream regulator of MMPs, in CNS biology.

Science.gov (United States)

Kaushik, Deepak Kumar; Hahn, Jennifer Nancy; Yong, V Wee

2015-01-01

Matrix metalloproteinases (MMPs) are engaged in pathologies associated with infections, tumors, autoimmune disorders and neurological dysfunctions. With the identification of an upstream regulator of MMPs, EMMPRIN (Extracellular matrix metalloproteinase inducer, CD147), it is relevant to address if EMMPRIN plays a role in the pathology of central nervous system (CNS) diseases. This would enable the possibility of a more upstream and effective therapeutic target. Indeed, conditions including gliomas, Alzheimer's disease (AD), multiple sclerosis (MS), and other insults such as hypoxia/ischemia show elevated levels of EMMPRIN which correlate with MMP production. In contrast, given EMMPRIN's role in CNS homeostasis with respect to regulation of monocarboxylate transporters (MCTs) and interactions with adhesion molecules including integrins, we need to consider that EMMPRIN may also serve important regulatory or protective functions. This review summarizes the current understanding of EMMPRIN's involvement in CNS homeostasis, its possible roles in escalating or reducing neural injury, and the mechanisms of EMMPRIN including and apart from MMP induction. Copyright © 2015 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

Efficacy of passive sampler collection for atmospheric NO2 isotopes under simulated environmental conditions.

Science.gov (United States)

Coughlin, Justin G; Yu, Zhongjie; Elliott, Emily M

2017-07-30

Nitrogen oxides or NO x (NO x = NO + NO 2 ) play an important role in air quality, atmospheric chemistry, and climate. The isotopic compositions of anthropogenic and natural NO 2 sources are wide-ranging, and they can be used to constrain sources of ambient NO 2 and associated atmospheric deposition of nitrogen compounds. While passive sample collection of NO 2 isotopes has been used in field studies to determine NO x source influences on atmospheric deposition, this approach has not been evaluated for accuracy or precision under different environmental conditions. The efficacy of NO 2 passive sampler collection for NO 2 isotopes was evaluated under varied temperature and relative humidity (RH) conditions in a dynamic flux chamber. The precision and accuracy of the filter NO 2 collection as nitrite (NO 2 - ) for isotopic analysis were determined using a reference NO 2 gas tank and through inter-calibration with a modified EPA Method 7. The bacterial denitrifer method was used to convert 20 μM of collected NO 2 - or nitrate (NO 3 - ) into N 2 O and was carried out on an Isoprime continuous flow isotope ratio mass spectrometer. δ 15 N-NO 2 values determined from passive NO 2 collection, in conditions of 11-34 °C, 1-78% RH, have an overall accuracy and precision of ±2.1 ‰, and individual run precision of ±0.6 ‰. δ 18 O-NO 2 values obtained from passive NO 2 sampler collection, under the same conditions, have an overall precision of ± 1.3 ‰. Suitable conditions for passive sampler collection of NO 2 isotopes are in environments ranging from 11 to 34 °C and 1 to 78% RH. The passive NO 2 isotope measurement technique provides an accurate method to determine variations in atmospheric δ 15 N-NO 2 values and a precise method for determining atmospheric δ 18 O-NO 2 values. The ability to measure NO 2 isotopes over spatial gradients at the same temporal resolution provides a unique perspective on the extent and seasonality of fluctuations in atmospheric NO 2

Upstream Tracking and the Decay $B^{0} \\to K^{+}\\pi^{-}\\mu^{+}\\mu^{-}$ at the LHCb Experiment

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00388407; Serra, Nicola; Steinkamp, Olaf; Storaci, Barbara

The LHCb detector is a single-arm forward spectrometer covering the pseudorapidity range $2 < \\eta < 5$, designed to search for indirect evidence of New Physics in $C\\!P$ violation and rare decays of beauty and charm hadrons. The unique geometry takes advantage of the large $b$ and $c$ quark production in the forward region at the LHC. The detector includes a high granularity silicon-strip vertex detector, a silicon-strip detector upstream of the magnet and three stations of silicon-strip detectors and straw drift tubes downstream of the magnet. This thesis is divided into two main parts. The first part details the development of improved algorithms to perform track reconstruction using the sub-detectors upstream of the LHCb magnet. A novel idea to perform upstream tracking as an intermediate step of the track reconstruction sequence was investigated. The vast gains in tracking performance obtained when using upstream tracks led to the algorithm being adopted into the default reconstruction sequence for...

Sheet GT1-1. Investigation of the hydrogeochemical behaviour of the Bellezane site; Fiche GT1-1. Etude du fonctionnement hydrogeochimique du site de Bellezane

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

This document reports the acquisition of geochemical and radiological data in waters and in the upstream and downstream environment of the ancient uranium mining site of Bellezane (France), and the continuous piezo-metric monitoring (every 6 hours) of water levels in the residues and in the mining reservoir

Assessing levels and seasonal variations of current-use pesticides (CUPs) in the Tuscan atmosphere, Italy, using polyurethane foam disks (PUF) passive air samplers

International Nuclear Information System (INIS)

Estellano, Victor H.; Pozo, Karla; Efstathiou, Christos; Pozo, Katerine; Corsolini, Simonetta; Focardi, Silvano

2015-01-01

Polyurethane foam disks (PUF) passive air samplers (PAS) were deployed over 4 sampling periods of 3–5-months (≥ 1 year) at ten urban and rural locations throughout the Tuscany Region. The purpose was to assess the occurrence and seasonal variations of ten current-use pesticides (CUPs). PUF disk extracts were analyzed using GC–MS. The organophosphates insecticides; chlorpyrifos (3–580 pg m −3 ) and chlorpyrifos-methyl (below detection limit – to 570 pg m −3 ) presented the highest levels in air, and showed seasonal fluctuation coinciding with the growing seasons. The relative proportion urban/(urban + rural) ranged from 0.4 to 0.7 showing no differences between urban and rural concentrations. Air back trajectories analysis showed air masses passing over agricultural fields and potentially enhancing the drift of pesticides into the urban sites. This study represents the first information regarding CUPs in the atmosphere of Tuscany region using PAS-PUF disk. - Highlights: • Current use pesticides (CUPs) were detected in the atmosphere of Tuscany, Italy. • Chlorpyrifos showed the highest concentrations in air with seasonal patterns. • CUPs levels might be influenced by agricultural activities. • No differences were detected between Urban and Rural sites. • Air mass analysis indicated the monitoring sites are influenced by local sources. - Seasonality of CUPs was measured in Tuscany, Italy. Chlorpyrifos showed the highest values. Urban and rural sites showed no differences. Agricultural activities influence CUPs levels in air

Numerical estimation of structure constants in the three-dimensional Ising conformal field theory through Markov chain uv sampler

Science.gov (United States)

Herdeiro, Victor

2017-09-01

Herdeiro and Doyon [Phys. Rev. E 94, 043322 (2016), 10.1103/PhysRevE.94.043322] introduced a numerical recipe, dubbed uv sampler, offering precise estimations of the conformal field theory (CFT) data of the planar two-dimensional (2D) critical Ising model. It made use of scale invariance emerging at the critical point in order to sample finite sublattice marginals of the infinite plane Gibbs measure of the model by producing holographic boundary distributions. The main ingredient of the Markov chain Monte Carlo sampler is the invariance under dilation. This paper presents a generalization to higher dimensions with the critical 3D Ising model. This leads to numerical estimations of a subset of the CFT data—scaling weights and structure constants—through fitting of measured correlation functions. The results are shown to agree with the recent most precise estimations from numerical bootstrap methods [Kos, Poland, Simmons-Duffin, and Vichi, J. High Energy Phys. 08 (2016) 036, 10.1007/JHEP08(2016)036].

Assessment of exposure to composite nanomaterials and development of a personal respiratory deposition sampler for nanoparticles

Science.gov (United States)

Cena, Lorenzo

2011-12-01

-fiber efficiency of the screens calculated from experimental data was in good agreement with that estimated from theory for particles between 40 and 150 nm but deviated from theory for particles outside of this range. New coefficients for the single-fiber efficiency model were identified that minimized the sum of square error (SSE) between the experimental values and those estimated with the model. Compared to the original theory, the SSE calculated using the modified theory was at least threefold lower for all screens and flow rates. Since nylon fibers produce no significant spectral interference when ashed for spectrometric examination, the ability to accurately estimate collection efficiency of submicrometer particles makes nylon mesh screens an attractive collection substrate for nanoparticles. In the third study, laboratory experiments were conducted to develop a novel nanoparticle respiratory deposition (NRD) sampler that selectively collects nanoparticles in a worker's breathing zone apart from larger particles. The NRD sampler consists of a respirable cyclone fitted with an impactor and a diffusion stage containing eight nylon-mesh screens. A sampling criterion for nano-particulate matter (NPM) was developed and set as the target for the collection efficiency of the NRD sampler. The sampler operates at 2.5 Lpm and fits on a worker's lapel. The cut-off diameter of the impactor was experimentally measured to be 300 nm with a sharpness of 1.53. Loading at typical workplace levels was found to have no significant effect (2-way ANOVA, p=0.257) on the performance of the impactor. The effective deposition of particles onto the diffusion stage was found to match the NPM criterion, showing that a sample collected with the NRD sampler represents the concentration of nanoparticles deposited in the human respiratory system.

Prototype particulate stack sampler with single-cut nozzle and microcomputer calculating/display system

International Nuclear Information System (INIS)

Eler, J.C.; Littlefield, L.G.; Tillery, M.I.

1979-01-01

A prototype particulate stack sampler (PPSS) has been developed to improve on the existing EPA Method 5 sampling apparatus. Its primary features are (1) higher sampling rate (56 1/min); (2) display (on demand) of all required variables and calculated values by a microcomputer-based calculating and display system; (3) continuous stack gas moisture determination; (4) a virtual impactor nozzle with 3 μm mass median diameter cutpoint which collects fine and coarse particle fractions on separate glass fiber filters; (5) a variable-area inlet to maintain isokinetic sampling conditions; and (6) conversion to stainless steel components from the glass specified by EPA Method 5. The basic sampling techniques of EPA Method 5 have been retained; however, versatility in the form of optional in-stack filters and general modernization of the stack sampler have been provided in the prototype design. Laboratory testing with monodisperse dye aerosols has shown the present variable inlet, virtual impactor nozzle to have a collection efficiency which is less than 77% and significant wall losses. This is primarily due to lack of symmetry in this rectangular jet impactor and short transition lengths dictated by physical design constraints (required passage of the nozzle through a 7.6 cm (3 in) diameter stack port). Electronic components have shown acceptable service in laboratory testing although no field testing of the prototype under a broad range of temperature, humidity, and SO 2 concentration has been undertaken

Calibration and use of the polar organic chemical integrative sampler--a critical review.

Science.gov (United States)

Harman, Christopher; Allan, Ian John; Vermeirssen, Etiënne L M

2012-12-01

The implementation of strict environmental quality standards for polar organic priority pollutants poses a challenge for monitoring programs. The polar organic chemical integrative sampler (POCIS) may help to address the challenge of measuring low and fluctuating trace concentrations of such organic contaminants, offering significant advantages over traditional sampling. In the present review, the authors evaluate POCIS calibration methods and factors affecting sampling rates together with reported environmental applications. Over 300 compounds have been shown to accumulate in POCIS, including pesticides, pharmaceuticals, hormones, and industrial chemicals. Polar organic chemical integrative sampler extracts have been used for both chemical and biological analyses. Several different calibration methods have been described, which makes it difficult to directly compare sampling rates. In addition, despite the fact that some attempts to correlate sampling rates with the properties of target compounds such as log K(OW) have been met with varying success, an overall model that can predict uptake is lacking. Furthermore, temperature, water flow rates, salinity, pH, and fouling have all been shown to affect uptake; however, there is currently no robust method available for adjusting for these differences. Overall, POCIS has been applied to a wide range of sampling environments and scenarios and has been proven to be a useful screening tool. However, based on the existing literature, a more mechanistic approach is required to increase understanding and thus improve the quantitative nature of the measurements. Copyright © 2012 SETAC.

Characterization of upstream sequences from the 8S globulin gene ...

African Journals Online (AJOL)

Administrator

2011-09-21

Sep 21, 2011 ... added recombinant proteins and enzymes for industries. The upstream region ... cost, eukaryotic expression and no endogenous patho- gen pollution, thus it ... developmental process (Santino et al., 1997) which may deplete nutrient ... ideal bioreactors for economic production and storage of value-added ...

Emerging investigator series: development and application of polymeric electrospun nanofiber mats as equilibrium-passive sampler media for organic compounds.

Science.gov (United States)

Qian, Jiajie; Jennings, Brandon; Cwiertny, David M; Martinez, Andres

2017-11-15

We fabricated a suite of polymeric electrospun nanofiber mats (ENMs) and investigated their performance as next-generation passive sampler media for environmental monitoring of organic compounds. Electrospinning of common polymers [e.g., polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), and polystyrene (PS), among others] yielded ENMs with reproducible control of nanofiber diameters (from 50 to 340 nm). The ENM performance was investigated initially with model hydrophilic (aniline and nitrobenzene) and hydrophobic (selected PCB congeners and dioxin) compounds, generally revealing fast chemical uptake into all of these ENMs, which was well described by a one compartment, first-order kinetic model. Typical times to reach 90% equilibrium (t 90% ) were ≤7 days under mixing conditions for all the ENMs and equilibrium timescales suggest that ENMs may be used in the field as an equilibrium-passive sampler, at least for our model compounds. Equilibrium partitioning coefficients (K ENM-W , L kg -1 ) averaged 2 and 4.7 log units for the hydrophilic and hydrophobic analytes, respectively. PAN, PMMA and PS were prioritized for additional studies because they exhibited not only the greatest capacity for simultaneous uptake of the entire model suite (log K ENM-W ∼1.5-6.2), but also fast uptake. For these optimized ENMs, the rates of uptake into PAN and PMMA were limited by aqueous phase diffusion to the nanofiber surface, and the rate-determining step for PS was analyte specific. Sorption isotherms also revealed that the environmental application of these optimized ENMs would occur within the linear uptake regime. We examined the ENM performance for the measurement of pore water concentrations from spiked soil and freshwater sediments. Soil and sediment studies not only yielded reproducible pore water concentrations and comparable values to other passive sampler materials, but also provided practical insights into ENM stability and fouling in such systems

Monitoring of bioaerosol inhalation risks in different environments using a six-stage Andersen sampler and the PCR-DGGE method.

Science.gov (United States)

Xu, Zhenqiang; Yao, Maosheng

2013-05-01

Increasing evidences show that inhalation of indoor bioaerosols has caused numerous adverse health effects and diseases. However, the bioaerosol size distribution, composition, and concentration level, representing different inhalation risks, could vary with different living environments. The six-stage Andersen sampler is designed to simulate the sampling of different human lung regions. Here, the sampler was used in investigating the bioaerosol exposure in six different environments (student dorm, hospital, laboratory, hotel room, dining hall, and outdoor environment) in Beijing. During the sampling, the Andersen sampler was operated for 30 min for each sample, and three independent experiments were performed for each of the environments. The air samples collected onto each of the six stages of the sampler were incubated on agar plates directly at 26 °C, and the colony forming units (CFU) were manually counted and statistically corrected. In addition, the developed CFUs were washed off the agar plates and subjected to polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) for diversity analysis. Results revealed that for most environments investigated, the culturable bacterial aerosol concentrations were higher than those of culturable fungal aerosols. The culturable bacterial and fungal aerosol fractions, concentration, size distribution, and diversity were shown to vary significantly with the sampling environments. PCR-DGGE analysis indicated that different environments had different culturable bacterial aerosol compositions as revealed by distinct gel band patterns. For most environments tested, larger (>3 μm) culturable bacterial aerosols with a skewed size distribution were shown to prevail, accounting for more than 60 %, while for culturable fungal aerosols with a normal size distribution, those 2.1-4.7 μm dominated, accounting for 20-40 %. Alternaria, Cladosporium, Chaetomium, and Aspergillus were found abundant in most

Entrepreneurial Leadership in Upstream Oil and Gas Industry

OpenAIRE

Kalu, Mona Ukpai

2015-01-01

The study examined Entrepreneurial leadership in Upstream Oil and Gas industry and its ability to accelerate innovative energy technology development. The declining deliverability from existing reservoirs and ever increasing demand for energy to fuel growth in many parts of the world is driving oil and gas exploration into more difficult to access reservoirs like bituminous sands and shale gas. Accelerating new innovative technology development to access these new streams of profitable oil an...

Comparison of a disposable sorptive sampler with thermal desorption in a gas chromatographic inlet, or in a dedicated thermal desorber, to conventional stir bar sorptive extraction-thermal desorption for the determination of micropollutants in water.

Science.gov (United States)

Wooding, Madelien; Rohwer, Egmont R; Naudé, Yvette

2017-09-01

The presence of micropollutants in the aquatic environment is a worldwide environmental concern. The diversity of micropollutants and the low concentration levels at which they may occur in the aquatic environment have greatly complicated the analysis and detection of these chemicals. Two sorptive extraction samplers and two thermal desorption methods for the detection of micropollutants in water were compared. A low-cost, disposable, in-house made sorptive extraction sampler was compared to SBSE using a commercial Twister sorptive sampler. Both samplers consisted of polydimethylsiloxane (PDMS) as a sorptive medium to concentrate micropollutants. Direct thermal desorption of the disposable samplers in the inlet of a GC was compared to conventional thermal desorption using a commercial thermal desorber system (TDS). Comprehensive gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOFMS) was used for compound separation and identification. Ten micropollutants, representing a range of heterogeneous compounds, were selected to evaluate the performance of the methods. The in-house constructed sampler, with its associated benefits of low-cost and disposability, gave results comparable to commercial SBSE. Direct thermal desorption of the disposable sampler in the inlet of a GC eliminated the need for expensive consumable cryogenics and total analysis time was greatly reduced as a lengthy desorption temperature programme was not required. Limits of detection for the methods ranged from 0.0010 ng L -1 to 0.19 ng L -1 . For most compounds, the mean (n = 3) recoveries ranged from 85% to 129% and the % relative standard deviation (% RSD) ranged from 1% to 58% with the majority of the analytes having a %RSD of less than 30%. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular characterization of a complex site-specific radiation-induced DNA double-strand break

International Nuclear Information System (INIS)

Datta, K.; Dizdaroglu, M.; Jaruga, P.; Neumann, R.D.; Winters, T.A.

2003-01-01

Radiation lethality is a function of radiation-induced DNA double-strand breaks (DSB). Current models propose the lethality of a DSB to be a function of its structural complexity. We present here for the first time a map of damage associated with a site-specific double-strand break produced by decay of 125 I in a plasmid bound by a 125 I-labeled triplex forming oligonucleotide ( 125 I-TFO). The E. coli DNA repair enzymes, endonuclease IV (endo IV), endonuclease III (endo III), and formamidopyrimidine-DNA glycosylase (Fpg), which recognize AP sites, and pyrimidine and purine base damage respectively, were used as probes in this study. 125 I-TFO bound plasmid was incubated with and without DMSO at -80 deg C for 1 month. No significant difference in DSB yield was observed under these conditions. A 32 base pair fragment from the upstream side of the decay site was isolated by restriction digestion and enzymatically probed to identify damage sites. Endo IV treatment of the 5'-end labeled upper strand indicated clustering of AP sites within 3 bases downstream and 7 bases upstream of the targeted base. Also, repeated experiments consistently detected an AP site 4 bases upstream of the 125 Itarget base. This was further supported by complementary results with the 3'-end labeled upper strand. Endo IV analysis of the lower strand also shows clustering of AP sites near the DSB end. Endo III and Fpg probing demonstrated that base damage is also clustered near the targeted break site. DSBs produced in the absence of DMSO displayed a different pattern of enzyme sensitive damage than those produced in the presence of DMSO. Identification of specific base damage types within the restriction fragment containing the DSB end was achieved with GC/MS. Base damage consisted of 8-hydroguanine, 8-hydroxyadenine, and 5-hydroxycytosine. These lesions were observed at relative yields of 8-hydroguanine and 5-hydroxycytosine to 8-hydroxyadenine of 7.4:1 and 4.7:1, respectively, in the absence

Determination of phenolic compounds in air by using cyclodextrin-silica hybrid microporous composite samplers.

Science.gov (United States)

Mauri-Aucejo, Adela R; Ponce-Català, Patricia; Belenguer-Sapiña, Carolina; Amorós, Pedro

2015-03-01

An analytical method for the determination of phenolic compounds in air samples based on the use of cyclodextrin-silica hybrid microporous composite samplers is proposed. The method allows the determination of phenol, guaiacol, cresol isomers, eugenol, 4-ethylphenol and 4-ethylguaiacol in workplaces according to the Norm UNE-EN 1076:2009 for active sampling. Therefore, the proposed method offers an alternative for the assessment of the occupational exposure to phenol and cresol isomers. The detection limits of the proposed method are lower than those for the NIOSH Method 2546. Storage time of samples almost reaches 44 days. Recovery values for phenol, guaiacol, o-cresol, m-cresol, p-cresol, 4-ethylguaiacol, eugenol and 4-ethylphenol are 109%, 99%, 102%, 94%, 94%, 91%, 95% and 102%, respectively with a coefficient of variation below 6%. The method has been applied to the assessment of exposure in different areas of a farm and regarding the quantification of these compounds in the vapors generated by burning incense sticks and an essential oil marketed as air fresheners. The acquired results are comparable with those provided from a reference method for a 95% of confidence level. The possible use of these samplers for the sampling of other toxic compounds such as phthalates is evaluated by qualitative analysis of extracts from incense sticks and essential oil samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Passive sampling - a tool for targeted screening of emerging pollutants in rivers

Science.gov (United States)

Kodes, Vit; Grabic, Roman

2016-04-01

A screening of more than 300 pollutants such as pharmaceuticals (analgesics, psycholeptics, antidepressants, antibiotics, beta blockers), PCPs (UV blockers, musk's, repellents), illicit drugs, pesticides, perfluorinated compounds and their metabolites at 22 monitoring sites throughout the Czech Republic was conducted in 2013. POCIS samplers were used in this study. Two types of passive samplers (pesticide and pharmaceutical POCIS) were deployed for 14 days in May and in October, 88 samples were collected in total. In total 265 and 310 target compounds were analyzed in pharmaceutical and pesticide samplers respectively. The chemicals of interest were extracted from the passive samplers according to standardized procedures. LC -MS/MS and LC-MS/HRMS methods were applied for analyses of extracts. 150 of 310 (48%) and 127 of 265 (48%) analyzed substances had been found in pesticide and pharmaceutical samplers respectively. 27 substances (pharmaceuticals, PCPs, pesticides, caffeine, nicotine metabolite cotinine) occurred at all sampled sites, additional 39 substances (pharmaceuticals, PCPs, pesticides) occurred at more than 17 (75%) sites. One of perfluorinated compounds (PFOA) occurred at 68% of sites, whilst one of illicit drugs (Methamphetamine) was found at 61% of sites. The highest number of contaminants found in one POCIS at a single monitoring site was 111. The concentrations varied from nanograms to thousands of nanograms per sampler. Emerging contaminants occurring in highest concentrations (> 1000 ng/sampler) were BP-4 and PBSA (UV blockers), caffeine, DEET (insect repellent), imidacloprid (insecticide), telmisartan (hypertension drug) and tramadol (analgesic). Monitoring in the Czech Republic has demonstrated that many target compounds enter river waters and a number of these compounds reach high concentrations.

Metal loading in Soda Butte Creek upstream of Yellowstone National Park, Montana and Wyoming; a retrospective analysis of previous research; and quantification of metal loading, August 1999

Science.gov (United States)

Boughton, G.K.

2001-01-01

Acid drainage from historic mining activities has affected the water quality and aquatic biota of Soda Butte Creek upstream of Yellowstone National Park. Numerous investigations focusing on metals contamination have been conducted in the Soda Butte Creek basin, but interpretations of how metals contamination is currently impacting Soda Butte Creek differ greatly. A retrospective analysis of previous research on metal loading in Soda Butte Creek was completed to provide summaries of studies pertinent to metal loading in Soda Butte Creek and to identify data gaps warranting further investigation. Identification and quantification of the sources of metal loading to Soda Butte Creek was recognized as a significant data gap. The McLaren Mine tailings impoundment and mill site has long been identified as a source of metals but its contribution relative to the total metal load entering Yellowstone National Park was unknown. A tracer-injection and synoptic-sampling study was designed to determine metal loads upstream of Yellowstone National Park.A tracer-injection and synoptic-sampling study was conducted on an 8,511-meter reach of Soda Butte Creek from upstream of the McLaren Mine tailings impoundment and mill site downstream to the Yellowstone National Park boundary in August 1999. Synoptic-sampling sites were selected to divide the creek into discrete segments. A lithium bromide tracer was injected continuously into Soda Butte Creek for 24.5 hours. Downstream dilution of the tracer and current-meter measurements were used to calculate the stream discharge. Stream discharge values, combined with constituent concentrations obtained by synoptic sampling, were used to quantify constituent loading in each segment of Soda Butte Creek.Loads were calculated for dissolved calcium, silica, and sulfate, as well as for dissolved and total-recoverable iron, aluminum, and manganese. Loads were not calculated for cadmium, copper, lead, and zinc because these elements were infrequently

A Tourist-like MITE insertion in the upstream region of the BnFLC.A10 gene is associated with vernalization requirement in rapeseed (Brassica napus L.

Directory of Open Access Journals (Sweden)

Hou Jinna

2012-12-01

Full Text Available Abstract Background Rapeseed (Brassica napus L. has spring and winter genotypes adapted to different growing seasons. Winter genotypes do not flower before the onset of winter, thus leading to a longer vegetative growth period that promotes the accumulation and allocation of more resources to seed production. The development of winter genotypes enabled the rapeseed to spread rapidly from southern to northern Europe and other temperate regions of the world. The molecular basis underlying the evolutionary transition from spring- to winter- type rapeseed is not known, however, and needs to be elucidated. Results We fine-mapped the spring environment specific quantitative trait locus (QTL for flowering time, qFT10-4,in a doubled haploid (DH mapping population of rapeseed derived from a cross between Tapidor (winter-type and Ningyou7 (semi-winter and delimited the qFT10-4 to an 80-kb region on chromosome A10 of B. napus. The BnFLC.A10 gene, an ortholog of FLOWERING LOCUS C (FLC in Arabidopsis, was cloned from the QTL. We identified 12 polymorphic sites between BnFLC.A10 parental alleles of the TN-DH population in the upstream region and in intron 1. Expression of both BnFLC.A10 alleles decreased during vernalization, but decreased more slowly in the winter parent Tapidor. Haplotyping and association analysis showed that one of the polymorphic sites upstream of BnFLC.A10 is strongly associated with the vernalization requirement of rapeseed (r2 = 0.93, χ2 = 0.50. This polymorphic site is derived from a Tourist-like miniature inverted-repeat transposable element (MITE insertion/deletion in the upstream region of BnFLC.A10. The MITE sequence was not present in the BnFLC.A10 gene in spring-type rapeseed, nor in ancestral ‘A’ genome species B. rapa genotypes. Our results suggest that the insertion may have occurred in winter rapeseed after B. napus speciation. Conclusions Our findings strongly suggest that (i BnFLC.A10 is the gene underlying qFT10

Benthic organisms collected using sediment sampler from the CAPT. BRADY J in the Gulf of Mexico from (NODC Accession 8300082)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the CAPT. BRADY J and CAJUN SPECIAL in the Gulf of Mexico from 03 May 1982 to 13 October 1982....

Transient digitizer with displacement current samplers

Science.gov (United States)

McEwan, Thomas E.

1996-01-01

A low component count, high speed sample gate, and digitizer architecture using the sample gates is based on use of a signal transmission line, a strobe transmission line and a plurality of sample gates connected to the sample transmission line at a plurality of positions. The sample gates include a strobe pickoff structure near the strobe transmission line which generates a charge displacement current in response to propagation of the strobe signal on the strobe transmission line sufficient to trigger the sample gate. The sample gate comprises a two-diode sampling bridge and is connected to a meandered signal transmission line at one end and to a charge-holding cap at the other. The common cathodes are reverse biased. A voltage step is propagated down the strobe transmission line. As the step propagates past a capacitive pickoff, displacement current i=c(dv/dT), flows into the cathodes, driving the bridge into conduction and thereby charging the charge-holding capacitor to a value related to the signal. A charge amplifier converts the charge on the charge-holding capacitor to an output voltage. The sampler is mounted on a printed circuit board, and the sample transmission line and strobe transmission line comprise coplanar microstrips formed on a surface of the substrate. Also, the strobe pickoff structure may comprise a planar pad adjacent the strobe transmission line on the printed circuit board.

Technological acceleration and organizational transformations in the upstream oil and gas industry

International Nuclear Information System (INIS)

Isabelle, M.

2000-12-01

The upstream oil and gas industry experienced a dramatic technological acceleration in the early 1970's. The relationships between the agents in this industry have themselves undergone deep changes since that date. This thesis shows that a tight link exists between the technological acceleration and the organizational transformations in the upstream oil and gas industry. In a first part, it focuses on the economic theory's developments concerning industrial organization. In a second part, it applies these developments to three types of relations: those between the owner-states of hydrocarbon resources and the international petroleum companies; those between the international petroleum companies and their subcontractors; and finally those between the international petroleum companies themselves. (author)

Pharmaceuticals, alkylphenols and pesticides in Mediterranean coastal waters: Results from a pilot survey using passive samplers

OpenAIRE

Munaron, Dominique; Tapie, Nathalie; Budzinski, Helene; Andral, Bruno; Gonzalez, Jean-louis

2012-01-01

21 pharmaceuticals, 6 alkylphenols and 27 hydrophilic pesticides and biocides were investigated using polar organic contaminant integrative samplers (POCIS) during a large-scale study of contamination of French Mediterranean coastal waters. Marine and transitional water-bodies, defined under the EU Water Framework Directive were monitored. Our results show that the French Mediterranean coastal waters were contaminated with a large range of emerging contaminants, detected at low concentrations...

Evaluation of physical sampling efficiency for cyclone-based personal bioaerosol samplers in moving air environments

OpenAIRE

Su, Wei-Chung; Tolchinsky, Alexander D.; Chen, Bean T.; Sigaev, Vladimir I.; Cheng, Yung Sung

2012-01-01

The need to determine occupational exposure to bioaerosols has notably increased in the past decade, especially for microbiology-related workplaces and laboratories. Recently, two new cyclone-based personal bioaerosol samplers were developed by the National Institute for Occupational Safety and Health (NIOSH) in the USA and the Research Center for Toxicology and Hygienic Regulation of Biopreparations (RCT & HRB) in Russia to monitor bioaerosol exposure in the workplace. Here, a series of wind...

Total Mercury and Methylmercury Contamination in Fish from Sites along the Elbe River

Directory of Open Access Journals (Sweden)

P. Maršálek

2006-01-01

Full Text Available The aim of the study was to evaluate total mercury Hg and methylmercury MeHg contamination in muscle tissues of fish collected in 2002 from the Labe (Elbe river at sites upstream of Pardubice and downstream of Pardubice and Hřensko, and in 2004 from the Labe river upstream and downstream of the Spolana factory in Neratovice, and from the Vltava river downstream of Lenora. Eighty eight fish of the following species were sampled: bream (Abramis brama L., perch (Perca fluviatilis L., chub (Leuciscus cephalus L. and barbel (Barbus barbus L.. Total mercury content in chub, perch and bream was in the range of 0.05 - 1.96 mg kg-1 w.w., 0. 09 - 1.46 mg kg-1 w.w. and 0.35 - 0.82 mg kg-1 w.w., respectively. Methylmercury content in chub, perch and bream was in the range of 0.04 - 2.11 mg kg-1 w.w., 0.1 - 1.73 mg kg-1 w.w. and 0.371 - 0.650 mg kg-1 w.w., respectively. Significant correlation (p p < 0.05 between THg and MeHg contents were found between individual sites. In 2002, for example, the most contaminated fish were found downstream of Pardubice, followed by fish from upstream of Pardubice and from Hřensko. In 2004, fish from downstream and upstream of the Spolana factory in Neratovice were more contaminated than fish from the Vltava river downstream of Lenora. The methylmercury-tototal mercury ratio in muscle tissue was close to 1.0.

The economic benefits of vegetation in the upstream area of Ciliwung watershed

Science.gov (United States)

Saridewi, T. R.; Nazaruddin

2018-04-01

Ciliwung watershed has strategic values since its entire downstream area is located in the Special Administrative Region of Jakarta (DKI Jakarta), the capital of Indonesia. This causes forest and farmland areas are converted into open areas or built-up areas. The existence of these areas provides enormous environmental and economic benefits. Economic benefit values are very important to be considered in developing a policy development plan, but they have not been calculated yet. This study aims to determine the economic benefits provided by trees and other vegetation anddevelops a development policy that takes into account simultaneously ecological and economic aspects. The study is conducted in the upstream Ciliwung watershed, by using land cover patterns in 1989, 2000, 2010 and 2014, and employs GIS and CITY green analysis. The results show that conversion of forest and farmland areas reduces the ability of Ciliwung upstream watershed to store water. Therefore, its ability to reduce the flow of surface has been decreased. This creates a decrease in the cost savings of annual stormwater, from US 15,175,721 in 1989 to US 13,317,469 in 2014. The Environmental Services Payment Policy (PES) for upstream community groups managing the watershed has been considered as a fairly effective policy.

Translational profiling of B cells infected with the Epstein-Barr virus reveals 5' leader ribosome recruitment through upstream open reading frames.

Science.gov (United States)

Bencun, Maja; Klinke, Olaf; Hotz-Wagenblatt, Agnes; Klaus, Severina; Tsai, Ming-Han; Poirey, Remy; Delecluse, Henri-Jacques

2018-04-06

The Epstein-Barr virus (EBV) genome encodes several hundred transcripts. We have used ribosome profiling to characterize viral translation in infected cells and map new translation initiation sites. We show here that EBV transcripts are translated with highly variable efficiency, owing to variable transcription and translation rates, variable ribosome recruitment to the leader region and coverage by monosomes versus polysomes. Some transcripts were hardly translated, others mainly carried monosomes, showed ribosome accumulation in leader regions and most likely represent non-coding RNAs. A similar process was visible for a subset of lytic genes including the key transactivators BZLF1 and BRLF1 in cells infected with weakly replicating EBV strains. This suggests that ribosome trapping, particularly in the leader region, represents a new checkpoint for the repression of lytic replication. We could identify 25 upstream open reading frames (uORFs) located upstream of coding transcripts that displayed 5' leader ribosome trapping, six of which were located in the leader region shared by many latent transcripts. These uORFs repressed viral translation and are likely to play an important role in the regulation of EBV translation.

Benthic organisms collected using sediment sampler from the EXCELLENCE in the Gulf of Mexico for 1979-12-19 (NODC Accession 8000603)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms were collected using sediment sampler casts from the EXCELLENCE in the Gulf of Mexico from 19 December 1979 to 19 December 1979. Data were...

ISEE/IMP Observations of simultaneous upstream ion events

International Nuclear Information System (INIS)

Mitchel, D.G.; Roelof, E.C.; Sanderson, T.R.; Reinhard, R.; Wenzel, K.

1983-01-01

Propagation of upstream energetic (50--200 keV) ions is analyzed in sixteen events observed simulataneously by solid state detectors on ISEE 3 at approx.200 R/sub E/ and on IMP 8 at approx.35 R/sub E/ from the earth. Conclusions are based on comparisons of the pitch angle distributions observed at the two spacecraft and transformed into the solar wind frame. They are beamlike at ISEE 3 and are confined to the outward hemisphere. When IMP 8 is furtherest from the bow shock, they are also usually beamlike, or hemispheric. However, when IMP 8 is closer to the bow shock, pancakelike distributions are observed. This systematic variation in the IMP 8 pitch angle distributions delimits a scattering region l< or approx. =14 R/sub E/ upstream of the earth's bow shock (l measured along the interplanetary magnetic field) that dominates ion propagation, influences the global distribution of fluxes in the foreshock, and may play a role in acceleration of the ions. When IMP 8 is beyond lapprox.15 R/sub E/, the propagation appears to be essentially scatter-free between IMP 8 and ISEE 3; this is deduced from the absence of earthward fluxes at IMP 8 as well as the tendency for the spin-averaged fluxes to be comparable at the two spacecraft

Identification and positional distribution analysis of transcription factor binding sites for genes from the wheat fl-cDNA sequences.

Science.gov (United States)

Chen, Zhen-Yong; Guo, Xiao-Jiang; Chen, Zhong-Xu; Chen, Wei-Ying; Wang, Ji-Rui

2017-06-01

The binding sites of transcription factors (TFs) in upstream DNA regions are called transcription factor binding sites (TFBSs). TFBSs are important elements for regulating gene expression. To date, there have been few studies on the profiles of TFBSs in plants. In total, 4,873 sequences with 5' upstream regions from 8530 wheat fl-cDNA sequences were used to predict TFBSs. We found 4572 TFBSs for the MADS TF family, which was twice as many as for bHLH (1951), B3 (1951), HB superfamily (1914), ERF (1820), and AP2/ERF (1725) TFs, and was approximately four times higher than the remaining TFBS types. The percentage of TFBSs and TF members showed a distinct distribution in different tissues. Overall, the distribution of TFBSs in the upstream regions of wheat fl-cDNA sequences had significant difference. Meanwhile, high frequencies of some types of TFBSs were found in specific regions in the upstream sequences. Both TFs and fl-cDNA with TFBSs predicted in the same tissues exhibited specific distribution preferences for regulating gene expression. The tissue-specific analysis of TFs and fl-cDNA with TFBSs provides useful information for functional research, and can be used to identify relationships between tissue-specific TFs and fl-cDNA with TFBSs. Moreover, the positional distribution of TFBSs indicates that some types of wheat TFBS have different positional distribution preferences in the upstream regions of genes.

Ion acceleration at the earth's bow shock: A review of observations in the upstream region

International Nuclear Information System (INIS)

Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.

1979-01-01

Positive ions are accelerated at or near the earth's bow shock and propagate into the upstream region. Two distinctly different population of these ions, distinguished by their greatly different spectral and angular widths, can be identified there. The type of ion population observed in the upstream region is strongly correlated with the presence or absence of long-period compresive waves in the solar wind. Very few ions are accelerated in the vicinity of the shock to energies much above about 100 keV. It is not yet clear whether the most energetic ions (i.e. those near 100 keV) are accelerated at the shock or in the broad disturbed region upstream from the shock. In either case stochastic acceleration by turbulent electrostatic fields seems to be the most viable candidate for the acceleration of the most energetic particles

Ion acceleration at the earth's bow shock: a review of observations in the upstream region

International Nuclear Information System (INIS)

Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.

1979-01-01

Positive ions are accelerated at or near the earth's bow shock and propagate into the upstream region. Two distinctly different populations of these ions, distinguished by their greatly different spectral and angular widths, can be identified there. The type of ion population observed in the upstream region is strongly correlated with the presence or absence of long-period compressive waves in the solar wind. Very few ions are accelerated in the vicinity of the shock to energies much above about 100 keV. It is not yet clear whether the most energetic ions (i.e., those near 100 keV) are accelerated at the shock or in broad disturbed region upstream from the shock. In either case stochastic acceleration by turbulent electrostatic fields seems to be the most viable candidate for the acceleration of the most energetic particles

Characterization of upstream sequences of the LIM2 gene that bind developmentally regulated and lens-specific proteins

Institute of Scientific and Technical Information of China (English)

HSU Heng; Robert L. CHURCH

2004-01-01

During lens development, lens epithelial cells differentiate into fiber cells. To date, four major lens fiber cell intrinsic membrane proteins (MIP) ranging in size from 70 kD to 19 kD have been characterized. The second most abundant lens fiber cell intrinsic membrane protein is MP19. This protein probably is involved with lens cell communication and relates with cataractogenesis. The aim of this research is to characterize upstream sequences of the MP19 (also called LIM2) gene that bind developmentally regulated and lens-specific proteins. We have used the gel mobility assays and corresponding competition experiments to identify and characterize cis elements within approximately 500 bases of LIM2 upstream sequences. Our studies locate the positions of some cis elements, including a "CA" repeat, a methylation Hha I island, an FnuD II site, an Ap1 and an Ap2 consensus sequences, and identify some specific cis elements which relate to lens-specific transcription of LIM2. Our experiments also preliminarily identify trans factors which bind to specific cis elements of the LIM2 promoter and/or regulate transcription of LIM2. We conclude that developmental regulation and coordination of the MP 19 gene in ocular lens fiber cells is controlled by the presence of specific cis elements that bind regulatory trans factors that affect LIM2 gene expression. DNA methylation is one mechanism of controlling LIM2 gene expression during lens development.

Endocrine disrupting activities of surface water associated with a West Virginia oil and gas industry wastewater disposal site

International Nuclear Information System (INIS)

Kassotis, Christopher D.; Iwanowicz, Luke R.; Akob, Denise M.; Cozzarelli, Isabelle M.; Mumford, Adam C.; Orem, William H.; Nagel, Susan C.

2016-01-01

Currently, > 95% of end disposal of hydraulic fracturing wastewater from unconventional oil and gas operations in the US occurs via injection wells. Key data gaps exist in understanding the potential impact of underground injection on surface water quality and environmental health. The goal of this study was to assess endocrine disrupting activity in surface water at a West Virginia injection well disposal site. Water samples were collected from a background site in the area and upstream, on, and downstream of the disposal facility. Samples were solid-phase extracted, and extracts assessed for agonist and antagonist hormonal activities for five hormone receptors in mammalian and yeast reporter gene assays. Compared to reference water extracts upstream and distal to the disposal well, samples collected adjacent and downstream exhibited considerably higher antagonist activity for the estrogen, androgen, progesterone, glucocorticoid and thyroid hormone receptors. In contrast, low levels of agonist activity were measured in upstream/distal sites, and were inhibited or absent at downstream sites with significant antagonism. Concurrent analyses by partner laboratories (published separately) describe the analytical and geochemical profiling of the water; elevated conductivity as well as high sodium, chloride, strontium, and barium concentrations indicate impacts due to handling of unconventional oil and gas wastewater. Notably, antagonist activities in downstream samples were at equivalent authentic standard concentrations known to disrupt reproduction and/or development in aquatic animals. Given the widespread use of injection wells for end-disposal of hydraulic fracturing wastewater, these data raise concerns for human and animal health nearby. - Highlights: • Oil and gas wastewater disposal may increase endocrine disrupting activity in water. • Tested EDC activity in surface water near oil and gas wastewater injection site. • Water downstream had significantly

Endocrine disrupting activities of surface water associated with a West Virginia oil and gas industry wastewater disposal site

Energy Technology Data Exchange (ETDEWEB)

Kassotis, Christopher D., E-mail: christopher.kassotis@duke.edu [Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States); Iwanowicz, Luke R. [U.S. Geological Survey, Leetown Science Center, Fish Health Branch, 11649 Leetown Road, Kearneysville, WV 25430 (United States); Akob, Denise M.; Cozzarelli, Isabelle M.; Mumford, Adam C. [U.S. Geological Survey, National Research Program, 12201 Sunrise Valley Drive, MS 430, Reston, VA 20192 (United States); Orem, William H. [U.S. Geological Survey, Eastern Energy Resources Science Center, 12201 Sunrise Valley Drive, MS 956, Reston, VA 20192 (United States); Nagel, Susan C., E-mail: nagels@health.missouri.edu [Department of Obstetrics, Gynecology and Women' s Health, University of Missouri, Columbia, MO 65211 (United States)

2016-07-01

Currently, > 95% of end disposal of hydraulic fracturing wastewater from unconventional oil and gas operations in the US occurs via injection wells. Key data gaps exist in understanding the potential impact of underground injection on surface water quality and environmental health. The goal of this study was to assess endocrine disrupting activity in surface water at a West Virginia injection well disposal site. Water samples were collected from a background site in the area and upstream, on, and downstream of the disposal facility. Samples were solid-phase extracted, and extracts assessed for agonist and antagonist hormonal activities for five hormone receptors in mammalian and yeast reporter gene assays. Compared to reference water extracts upstream and distal to the disposal well, samples collected adjacent and downstream exhibited considerably higher antagonist activity for the estrogen, androgen, progesterone, glucocorticoid and thyroid hormone receptors. In contrast, low levels of agonist activity were measured in upstream/distal sites, and were inhibited or absent at downstream sites with significant antagonism. Concurrent analyses by partner laboratories (published separately) describe the analytical and geochemical profiling of the water; elevated conductivity as well as high sodium, chloride, strontium, and barium concentrations indicate impacts due to handling of unconventional oil and gas wastewater. Notably, antagonist activities in downstream samples were at equivalent authentic standard concentrations known to disrupt reproduction and/or development in aquatic animals. Given the widespread use of injection wells for end-disposal of hydraulic fracturing wastewater, these data raise concerns for human and animal health nearby. - Highlights: • Oil and gas wastewater disposal may increase endocrine disrupting activity in water. • Tested EDC activity in surface water near oil and gas wastewater injection site. • Water downstream had significantly

Determination of radionuclide concentrations in ground level air using the ASS-500 high volume sampler

International Nuclear Information System (INIS)

Frenzel, E.; Arnold, D.; Wershofen, H.

1996-01-01

A method for determination of radionuclide concentrations in air aerosol samples collected by the high volume aerosol sampler ASS-500 was elaborated. The aerosol sampling station ASS-500 is a Stand alone, all-weather proofed instrument. It is designed for representative sampling of airborne radionuclides from ground level air at a height of about 1.5 m above ground level. The ASS-500 station enables continuous air monitoring both normal and emergency Situations. The collection of aerosols on the Petrianov FPP-15-1.5 type filter out of an air volume of about 100,000 m 3 (sampling period 1 wk) or of about 250,000 m 3 (sampling period 3 wk) admits accurate spectrometric low level measurements of natural and artificial radionuclides. The achieved detection limit is 0.5 μBq m -3 and 0.2 μBq m -3 for 137 Cs, respectively. A new developed air flow Meter system allows to enhance the collected air volume to about 150,000 m 3 per week and lowers the detection limit to -3 for 137 Cs for weekly collected aerosol samples. In Poland the CLOR uses 9 Stations ASS-500 at different sites as atmospheric radioactivity control system. On the basis of spectrometric measurements of natural and artificial radionuclides in the collected aerosol samples at the different sites, CLOR establishes a weekly report about the radiological situation at Poland for responsible authorities. The very low achievable detection limit of the Station ASS-500 due 10 the high air flow fate and the long possible sampling period were the key argument for other government radiation protection authorities in Europe to introduce the Station ASS-500 into their low level radionuclide atmospheric monitoring programs (Austria, Belarus, France, Germany, Iceland, Spain, Switzerland, Ukraine)

Reservoir Sedimentation and Upstream Sediment Sources: Perspectives and Future Research Needs on Streambank and Gully Erosion

Science.gov (United States)

Fox, G. A.; Sheshukov, A.; Cruse, R.; Kolar, R. L.; Guertault, L.; Gesch, K. R.; Dutnell, R. C.

2016-05-01

The future reliance on water supply and flood control reservoirs across the globe will continue to expand, especially under a variable climate. As the inventory of new potential dam sites is shrinking, construction of additional reservoirs is less likely compared to simultaneous flow and sediment management in existing reservoirs. One aspect of this sediment management is related to the control of upstream sediment sources. However, key research questions remain regarding upstream sediment loading rates. Highlighted in this article are research needs relative to measuring and predicting sediment transport rates and loading due to streambank and gully erosion within a watershed. For example, additional instream sediment transport and reservoir sedimentation rate measurements are needed across a range of watershed conditions, reservoir sizes, and geographical locations. More research is needed to understand the intricate linkage between upland practices and instream response. A need still exists to clarify the benefit of restoration or stabilization of a small reach within a channel system or maturing gully on total watershed sediment load. We need to better understand the intricate interactions between hydrological and erosion processes to improve prediction, location, and timing of streambank erosion and failure and gully formation. Also, improved process-based measurement and prediction techniques are needed that balance data requirements regarding cohesive soil erodibility and stability as compared to simpler topographic indices for gullies or stream classification systems. Such techniques will allow the research community to address the benefit of various conservation and/or stabilization practices at targeted locations within watersheds.

A scheme for regulating toxic substances to water quality of Chamsil upstream water system

Energy Technology Data Exchange (ETDEWEB)

Kim, Kang Suk; Kim, Jee Hoon [Korea Environment Institute, Seoul (Korea)

1998-12-01

This study asserts to reflect a concept of toxicity thoroughly in the present water quality concept. It presents an appropriate solution to control toxic substances flowing into the Chamsil upstream water system. Although a regulation of toxic substances into major rivers in Korea other than Han river is also required urgently, it will be studied in future. It is expected that this study on Chamsil upstream would be a cornerstone for establishing a national regulation policy of toxic substances into water system. 28 refs., 1 fig., 36 tabs.

Lessons learned from a review of post-accident sampling systems, high range effluent monitors and high concentration particulate iodine samplers

International Nuclear Information System (INIS)

Hull, A.P.; Knox, W.H.; White, J.R.

1987-01-01

Post-accident sampling systems (PASS), high range gaseous effluent monitors and sampling systems for particulates and iodine in high concentrations have been reviewed at twenty-one licensee sites in Region I of the US Nuclear Regulatory Commission which includes fifteen BWR's and fourteen PWR's. Although most of the installed PASS met the criteria, the highest operational readiness was found in on-line systems that were also used for routine sampling and analysis. The detectors used in the gaseous effluent monitors included external ion chambers, GM tubes, organic scintillators and Cd-Te solid state crystals. Although all were found acceptable, each had its own inherent limitations in the conversion of detector output to the time varying concentration of a post-accident mixture of noble gases. None of the installed particulate and iodine samplers fully met all of the criteria. Their principal limitations included a lack of documentation showing that they could obtain a representative sample and that many of them would collect of an excessive amount of activity at the design criteria. 10 refs., 4 figs., 5 tabs

Concentrations of pollutants in fogwaters using a Grunow fogwater sampler

Energy Technology Data Exchange (ETDEWEB)

Schrimpff, E.; Klemm, O.; Eiden, R.; Frevert, T.; Herrmann, R.

1984-02-01

A simple device for sampling fog water is described (modified passive Grunow sampler), and analytical results as were found in rain and fog waters are reported. All samples were taken in the northern part of the Frankenwald mountains (near Bad Steben) from November 1982 until March 1983. Specific conductivity (..mu..Sxcm/sup -1/, 20/sup 0/C), titration acidity, Cl/sup -/, NO/sub 3//sup -/, SO/sub 4//sup 2 -/, total hardness, Ca, Na, Fe, Cd, Pb, TDOC and the polycyclic aromates fluoranthene and 3.4-benzopyrene were continuously higher in fog than in rain water. pH's were remarkably decreased in fog water. Here extreme results were measured in the first two weeks of March with pH 2.5, and acidities proportional2 mequivxl/sup -1/. Possible reasons for such extraordinary concentrations are discussed meteorologically as well as hydrochemically.

Experimental Branch Retinal Vein Occlusion Induces Upstream Pericyte Loss and Vascular Destabilization.

Directory of Open Access Journals (Sweden)

Elisa Dominguez

Full Text Available Branch retinal vein occlusion (BRVO leads to extensive vascular remodeling and is important cause of visual impairment. Although the vascular morphological changes following experimental vein occlusion have been described in a variety of models using angiography, the underlying cellular events are ill defined.We here show that laser-induced experimental BRVO in mice leads to a wave of TUNEL-positive endothelial cell (EC apoptosis in the upstream vascular network associated with a transient edema and hemorrhages. Subsequently, we observe an induction of EC proliferation within the dilated vein and capillaries, detected by EdU incorporation, and the edema resolves. However, the pericytes of the upstream capillaries are severely reduced, which was associated with continuing EC apoptosis and proliferation. The vascular remodeling was associated with increased expression of TGFβ, TSP-1, but also FGF2 expression. Exposure of the experimental animals to hypoxia, when pericyte (PC dropout had occurred, led to a dramatic increase in endothelial cell proliferation, confirming the vascular instability induced by the experimental BRVO.Experimental BRVO leads to acute endothelial cells apoptosis and increased permeability. Subsequently the upstream vascular network remains destabilized, characterized by pericyte dropout, un-physiologically high endothelial cells turnover and sensitivity to hypoxia. These early changes might pave the way for capillary loss and subsequent chronic ischemia and edema that characterize the late stage disease.

Calibration of the Chemcatcher passive sampler for monitoring selected polar and semi-polar pesticides in surface water

International Nuclear Information System (INIS)

Gunold, Roman; Schaefer, Ralf Bernhard; Paschke, Albrecht; Schueuermann, Gerrit; Liess, Matthias

2008-01-01

Passive sampling is a powerful method for continuous pollution monitoring, but calibration experiments are still needed to generate sampling rates in order to estimate water concentrations for polar compounds. We calibrated the Chemcatcher device with an uncovered SDB-XC Empore disk as receiving phase for 12 polar and semi-polar pesticides in aquatic environments in flow-through tank experiments at two water flow velocities (0.135 m/s and 0.4 m/s). In the 14-day period of exposure the uptake of test substances in the sampler remained linear, and all derived sampling rates R s were in the range of 0.1 to 0.5 L/day. By additionally monitoring the release of two preloaded polar pesticides from the SDB-XC disks over time, very high variation in release kinetics was found, which calls into question the applicability of performance reference compounds. Our study expands the applicability of the Chemcatcher for monitoring trace concentrations of pesticides with frequent occurrence in water. - We calibrated the Chemcatcher passive sampler for current-use polar pesticides in surface waters, allowing its application in future monitoring studies

A rapidly equilibrating, thin film, passive water sampler for organic contaminants; characterization and field testing

Energy Technology Data Exchange (ETDEWEB)

St George, Tiffany [Department of Marine Science, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340 (United States); Department of Science, United States Coast Guard Academy, 27 Mohegan Ave., New London, CT 06320 (United States); Vlahos, Penny, E-mail: penny.vlahos@uconn.ed [Department of Chemistry, University of Connecticut, 55 Eagleville Road, Storrs, CT 06269 (United States); Department of Marine Science, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340 (United States); Harner, Tom [Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4 (Canada); Helm, Paul [Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, 125 Resources Rd, Toronto, Ontario M9P 3V6 (Canada); Wilford, Bryony [Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4 (Canada)

2011-02-15

Improving methods for assessing the spatial and temporal resolution of organic compound concentrations in marine environments is important to the sustainable management of our coastal systems. Here we evaluate the use of ethylene vinyl acetate (EVA) as a candidate polymer for thin-film passive sampling in waters of marine environments. Log K{sub EVA-W} partition coefficients correlate well (r{sup 2} = 0.87) with Log K{sub OW} values for selected pesticides and polychlorinated biphenyls (PCBs) where Log K{sub EVA-W} = 1.04 Log K{sub OW} + 0.22. EVA is a suitable polymer for passive sampling due to both its high affinity for organic compounds and its ease of coating at sub-micron film thicknesses on various substrates. Twelve-day field deployments were effective in detecting target compounds with good precision making EVA a potential multi-media fugacity meter. - Research highlights: Calibration and field testing of a thin-film passive sampler in marine systems. Ethylene vinyl acetate (EVA) is effective for a wide spectrum of organic compounds. EVA performs with high precision and reproducibility. EVA is effective in marine systems at environmentally relevant concentrations. EVA is recommended as a multi-media fugacity meter for environmental applications. - An ethylene vinyl acetate (EVA), thin-film passive sampler for the detection of organic compounds in marine environments is calibrated and field tested.

Auto-Gopher: A Wireline Deep Sampler Driven by Piezoelectric Percussive Actuator and EM Rotary Motor

Science.gov (United States)

Badescu, Mircea; Ressa, Aaron; Jae Lee, Hyeong; Bar-Cohen, Yoseph; Sherrit, Stewart; Zacny, Kris; Paulsen, Gale L.; Beegle, Luther; Bao, Xiaoqi

2013-01-01

The ability to penetrate subsurfaces and perform sample acquisition at depth of meters may be critical for future NASA in-situ exploration missions to bodies in the solar system, including Mars and Europa. A corer/sampler was developed with the goal of enabling acquisition of samples from depths of several meters where if used on Mars would be beyond the oxidized and sterilized zone. For this purpose, we developed a rotary-hammering coring drill, called Auto-Gopher, which employs a piezoelectric actuated percussive mechanism for breaking formations and an electric motor that rotates the bit to remove the powdered cuttings. This sampler is a wireline mechanism that can be fed into and retrieved from the drilled hole using a winch and a cable. It includes an inchworm anchoring mechanism allowing the drill advancement and weight on bit control without twisting the reeling and power cables. The penetration rate is being optimized by simultaneously activating the percussive and rotary motions of the Auto-Gopher. The percussive mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that is driven by piezoelectric stack and that was demonstrated to require low axial preload. The design and fabrication of this device were presented in previous publications. This paper presents the results of laboratory and field tests and lessons learned from this development.

Personal samplers of bioavailable pesticides integrated with a hair follicle assay of DNA damage to assess environmental exposures and their associated risks in children.

Science.gov (United States)

Vidi, Pierre-Alexandre; Anderson, Kim A; Chen, Haiying; Anderson, Rebecca; Salvador-Moreno, Naike; Mora, Dana C; Poutasse, Carolyn; Laurienti, Paul J; Daniel, Stephanie S; Arcury, Thomas A

2017-10-01

Agriculture in the United States employs youth ages ten and older in work environments with high pesticide levels. Younger children in rural areas may also be affected by indirect pesticide exposures. The long-term effects of pesticides on health and development are difficult to assess and poorly understood. Yet, epidemiologic studies suggest associations with cancer as well as cognitive deficits. We report a practical and cost-effective approach to assess environmental pesticide exposures and their biological consequences in children. Our approach combines silicone wristband personal samplers and DNA damage quantification from hair follicles, and was tested as part of a community-based participatory research (CBPR) project involving ten Latino children from farmworker households in North Carolina. Our study documents high acceptance among Latino children and their caregivers of these noninvasive sampling methods. The personal samplers detected organophosphates, organochlorines, and pyrethroids in the majority of the participants (70%, 90%, 80%, respectively). Pesticides were detected in all participant samplers, with an average of 6.2±2.4 detections/participant sampler. DNA damage in epithelial cells from the sheath and bulb of plucked hairs follicles was quantified by immunostaining 53BP1-labled DNA repair foci. This method is sensitive, as shown by dose response analyses to γ radiations where the lowest dose tested (0.1Gy) led to significant increased 53BP1 foci density. Immunolabeling of DNA repair foci has significant advantages over the comet assay in that specific regions of the follicles can be analyzed. In this cohort of child participants, significant association was found between the number of pesticide detections and DNA damage in the papilla region of the hairs. We anticipate that this monitoring approach of bioavailable pesticides and genotoxicity will enhance our knowledge of the biological effects of pesticides to guide education programs and

Characterization of wind velocities in the upstream induction zone of a wind turbine using scanning continuous-wave lidars

DEFF Research Database (Denmark)

Simley, Eric; Angelou, Nikolas; Mikkelsen, Torben Krogh

2016-01-01

As a wind turbine generates power, induced velocities, lower than the freestream velocity, will be present upstream of the turbine due to perturbation of the flow by the rotor. In this study, the upstream induction zone of a 225kW horizontal axis Vestas V27 wind turbine located at the Danish...... Technical University’s Risø campus is investigated using a scanning Light Detection and Ranging (lidar) system. Three short-range continuous-wave “WindScanner” lidars are positioned in the field around the V27 turbine allowing detection of all three components of the wind velocity vectors within...... the induction zone. The time-averaged mean wind speeds at different locations in the upstream induction zone are measured by scanning a horizontal plane at hub height and a vertical plane centered at the middle of the rotor extending roughly 1.5 rotor diameters (D) upstream of the rotor. Turbulence statistics...

Honey Bees (Apis mellifera, L.) as Active Samplers of Airborne Particulate Matter.

Science.gov (United States)

Negri, Ilaria; Mavris, Christian; Di Prisco, Gennaro; Caprio, Emilio; Pellecchia, Marco

2015-01-01

Honey bees (Apis mellifera L.) are bioindicators of environmental pollution levels. During their wide-ranging foraging activity, these hymenopterans are exposed to pollutants, thus becoming a useful tool to trace the environmental contaminants as heavy metals, pesticides, radionuclides and volatile organic compounds. In the present work we demonstrate that bees can also be used as active samplers of airborne particulate matter. Worker bees were collected from hives located in a polluted postmining area in South West Sardinia (Italy) that is also exposed to dust emissions from industrial plants. The area is included in an official list of sites of national interest for environmental remediation, and has been characterized for the effects of pollutants on the health of the resident population. The head, wings, hind legs and alimentary canal of the bees were investigated with Scanning Electron Microscopy coupled with X-ray spectroscopy (SEM-EDX). The analyses pointed to specific morphological and chemical features of the particulate, and resulted into the identification of three categories of particles: industry-, postmining-, and soil-derived. With the exception of the gut, all the analyzed body districts displayed inorganic particles, mostly concentrated in specific areas of the body (i.e. along the costal margin of the fore wings, the medial plane of the head, and the inner surface of the hind legs). The role of both past mining activities and the industrial activity close to the study area as sources of the particulate matter is also discussed. We conclude that honey bees are able to collect samples of the main airborne particles emitted from different sources, therefore could be an ideal tool for monitoring such a kind of pollutants.

PROMoter uPstream Transcripts share characteristics with mRNAs and are produced upstream of all three major types of mammalian promoters

DEFF Research Database (Denmark)

Preker, Pascal; Almvig, Kristina; Christensen, Marianne S

2011-01-01

RNAs, PROMPTs are largely nuclear and rapidly turned over by the RNA exosome. PROMPT-transcribing DNA is occupied by RNA polymerase II (RNAPII) complexes with serine 2 phosphorylated C-terminal domains (CTDs), mimicking that of the associated genic region. Thus, the inefficient elongation capacity of PROMPT...... transcription cannot solely be assigned to poor CTD phosphorylation. Conditions that reduce gene transcription increase RNAPII occupancy of the upstream PROMPT region, suggesting that they reside in a common transcription compartment. Surprisingly, gene promoters that are actively transcribed by RNAPI...

Essential roles of caspases and their upstream regulators in rotenone-induced apoptosis

International Nuclear Information System (INIS)

Lee Jihjong; Huang, M.-S.; Yang, I-C.; Lai, T.-C.; Wang, J.-L.; Pang, V.F.; Hsiao, M.; Kuo, M.Y.P.

2008-01-01

In the present study, we examined whether caspases and their upstream regulators are involved in rotenone-induced cytotoxicity. Rotenone significantly inhibited the proliferation of oral cancer cell lines in a dose-dependent manner compared to normal oral mucosal fibroblasts. Flow cytometric analysis of DNA content showed that rotenone treatment induced apoptosis following G2/M arrest. Western blotting showed activation of both the caspase-8 and caspase-9 pathways, which differed from previous studies conducted in other cell types. Furthermore, p53 protein and its downstream pro-apoptotic target, Bax, were induced in SAS cells after treatment with rotenone. Rotenone-induced apoptosis was inhibited by antioxidants (glutathione, N-acetylcysteine, and tiron). In conclusion, our results demonstrate significant involvement of caspases and their upstream regulators in rotenone-induced cytotoxicity

Sensor transition failure in the high flow sampler: Implications for methane emission inventories of natural gas infrastructure.

Science.gov (United States)

Howard, Touché; Ferrara, Thomas W; Townsend-Small, Amy

2015-07-01

Quantification of leaks from natural gas (NG) infrastructure is a key step in reducing emissions of the greenhouse gas methane (CH4), particularly as NG becomes a larger component of domestic energy supply. The U.S. Environmental Protection Agency (EPA) requires measurement and reporting of emissions of CH4 from NG transmission, storage, and processing facilities, and the high-flow sampler (or high-volume sampler) is one of the tools approved for this by the EPA. The Bacharach Hi-Flow Sampler (BHFS) is the only commercially available high-flow instrument, and it is also used throughout the NG supply chain for directed inspection and maintenance, emission factor development, and greenhouse gas reduction programs. Here we document failure of the BHFS to transition from a catalytic oxidation sensor used to measure low NG (~5% or less) concentrations to a thermal conductivity sensor for higher concentrations (from ~5% to 100%), resulting in underestimation of NG emission rates. Our analysis includes both our own field testing and analysis of data from two other studies (Modrak et al., 2012; City of Fort Worth, 2011). Although this failure is not completely understood, and although we do not know if all BHFS models are similarly affected, sensor transition failure has been observed under one or more of these conditions: (1) Calibration is more than ~2 weeks old; (2) firmware is out of date; or (3) the composition of the NG source is less than ~91% CH4. The extent to which this issue has affected recent emission studies is uncertain, but the analysis presented here suggests that the problem could be widespread. Furthermore, it is critical that this problem be resolved before the onset of regulations on CH4 emissions from the oil and gas industry, as the BHFS is a popular instrument for these measurements. An instrument commonly used to measure leaks in natural gas infrastructure has a critical sensor transition failure issue that results in underestimation of leaks, with

Preliminary site characterization radiological monitoring plan for the Nevada Nuclear Waste Storage Investigations Project, Yucca Mountain Site

International Nuclear Information System (INIS)

1987-03-01

The activities described in this plan occur in the early phases of site characterization. This document presents the Preliminary Site Characterization Radiological Monitoring Plan (PSCRMP) for collecting and evaluating data in support of the NNWSI Project. The PSCRMP defines and identifies control procedures for the monitoring activities. The PSCRMP activity will utilize integrating radon monitoring devices, a continuous radon monitor, and a particulate air sampler. These instruments will be used to establish the baseline radioactivity and/or radioactivity released due to early site characterization activities. The sections that follow provide a general project description, the specifics of the monitoring program, and the practices that will be employed to ensure the validity of the collected data by integrating quality assurance into all activities. Section 2 of this document describes the regulatory base of this document. Section 3 describes the site characterization activities which may lead to release of radioactivity. Section 4 provides a description of the potential sources of radioactivity that site characterization could generate. Section 5 summarizes the sampling and monitoring methodology, which will be used to monitor the potential sources of radioactivity. The network of sampling and monitoring equipment is described in Section 6, and Section 7 summarizes the systems operation activities. The data reporting activities are described in Section 8. Finally, a description of the Quality Assurance (QA) and Quality Control (QC) activities is provided in Section 9. Appendix A contains a summary of the procedures to be used in this program, and Appendix B contains technical specification on equipment and services. 20 refs., 11 figs., 2 tabs

An upstream open reading frame modulates ebola virus polymerase translation and virus replication.

Directory of Open Access Journals (Sweden)

Reed S Shabman

2013-01-01

Full Text Available Ebolaviruses, highly lethal zoonotic pathogens, possess longer genomes than most other non-segmented negative-strand RNA viruses due in part to long 5' and 3' untranslated regions (UTRs present in the seven viral transcriptional units. To date, specific functions have not been assigned to these UTRs. With reporter assays, we demonstrated that the Zaire ebolavirus (EBOV 5'-UTRs lack internal ribosomal entry site function. However, the 5'-UTRs do differentially regulate cap-dependent translation when placed upstream of a GFP reporter gene. Most dramatically, the 5'-UTR derived from the viral polymerase (L mRNA strongly suppressed translation of GFP compared to a β-actin 5'-UTR. The L 5'-UTR is one of four viral genes to possess upstream AUGs (uAUGs, and ablation of each uAUG enhanced translation of the primary ORF (pORF, most dramatically in the case of the L 5'-UTR. The L uAUG was sufficient to initiate translation, is surrounded by a "weak" Kozak sequence and suppressed pORF translation in a position-dependent manner. Under conditions where eIF2α was phosphorylated, the presence of the uORF maintained translation of the L pORF, indicating that the uORF modulates L translation in response to cellular stress. To directly address the role of the L uAUG in virus replication, a recombinant EBOV was generated in which the L uAUG was mutated to UCG. Strikingly, mutating two nucleotides outside of previously-defined protein coding and cis-acting regulatory sequences attenuated virus growth to titers 10-100-fold lower than a wild-type virus in Vero and A549 cells. The mutant virus also exhibited decreased viral RNA synthesis as early as 6 hours post-infection and enhanced sensitivity to the stress inducer thapsigargin. Cumulatively, these data identify novel mechanisms by which EBOV regulates its polymerase expression, demonstrate their relevance to virus replication and identify a potential therapeutic target.

Experience of molecular monitoring techniques in upstream oil and gas operations

Energy Technology Data Exchange (ETDEWEB)

Mitchell, Anthony F.; Anfindsen, Hilde; Liengen, Turid; Molid, Solfrid [Statoil ASA (Denmark)

2011-07-01

For a numbers of years, molecular monitoring tools have been used in upstream oil and gas operations but the results have given only limited added value. This paper discusses the various techniques available for upstream molecular monitoring which provides scope for identification of microbial influenced problems. The methodology, which consists of analyzing solid samples using traditional as well as molecular techniques, is detailed. Two cases were studied with the objective of determining if microbial contamination was contributing to the problem. The first case was a study of amorphous deposits in production wells and mainly iron sulphide was found. The second study was of amorphous deposits in water injection wells and the analysis showed typical components of drilling and completion fluids with some organic material. Two more cases, corrosion of tubing in a water injection well and flow line corrosion, are discussed and the results are given. From the study, it can be concluded that failure can be due to several factors, chemical and biological.

Role of nitric oxide in vasodilation in upstream muscle during intermittent pneumatic compression.

Science.gov (United States)

Chen, Long-En; Liu, Kang; Qi, Wen-Ning; Joneschild, Elizabeth; Tan, Xiangling; Seaber, Anthony V; Stamler, Jonathan S; Urbaniak, James R

2002-02-01

This study investigated the dosage effects of nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-L-arginine (L-NMMA) on intermittent pneumatic compression (IPC)-induced vasodilation in uncompressed upstream muscle and the effects of IPC on endothelial NOS (eNOS) expression in upstream muscle. After L-NMMA infusion, mean arterial pressure increased by 5% from baseline (99.5 +/- 18.7 mmHg; P < 0.05). Heart rate and respiratory rate were not significantly affected. One-hour IPC application on legs induced a 10% dilation from baseline in 10- to 20-microm arterioles and a 10-20% dilation in 21- to 40 microm arterioles and 41- to 70-microm arteries in uncompressed cremaster muscle. IPC-induced vasodilation was dose dependently reduced, abolished, or even reversed by concurrently infused L-NMMA. Moreover, expression of eNOS mRNA in uncompressed cremaster muscle was upregulated to 2 and 2.5 times normal at the end of 1- and 5-h IPC on legs, respectively, and the expression of eNOS protein was upregulated to 1.8 times normal. These increases returned to baseline level after cessation of IPC. The results suggest that eNOS plays an important role in regulating the microcirculation in upstream muscle during IPC.

Relative efficiencies of the Burkard 7-Day, Rotorod and Burkard Personal samplers for Poaceae and Urticaceae pollen under field conditions

DEFF Research Database (Denmark)

Peel, Robert George; Kennedy, Roy; Smith, Matt

2014-01-01

Introduction: In aerobiological studies it is often necessary to compare concentration data recorded with different models of sampling instrument. Sampler efficiency typically varies from device to device, and depends on the target aerosol and local atmospheric conditions. To account for these di...

Development of a passive sampler for gaseous mercury

Science.gov (United States)

Gustin, M. S.; Lyman, S. N.; Kilner, P.; Prestbo, E.

2011-10-01

Here we describe work toward development of the components of a cost effective passive sampling system for gaseous Hg that could be broadly deployed by nontechnical staff. The passive sampling system included an external shield to reduce turbulence and exposure to precipitation and dust, a diffusive housing that directly protects the collection surface during deployment and handling, and a collection surface. A protocol for cleaning and deploying the sampler and an analytical method were developed. Our final design consisted of a polycarbonate external shield enclosing a custom diffusive housing made from expanded PTFE tubing. Two collection surfaces were investigated, gold sputter-coated quartz plates and silver wires. Research showed the former would require extensive quality control for use, while the latter had interferences with other atmosphere constituents. Although the gold surface exhibited the best performance over space and time, gradual passivation would limit reuse. For both surfaces lack of contamination during shipping, deployment and storage indicated that the handling protocols developed worked well with nontechnical staff. We suggest that the basis for this passive sampling system is sound, but further exploration and development of a reliable collection surface is needed.

Sodium Pick-Up Ion Observations in the Solar Wind Upstream of Mercury

Science.gov (United States)

Jasinski, J. M.; Raines, J. M.; Slavin, J. A.; Regoli, L. R.; Murphy, N.

2018-05-01

We present the first observations of sodium pick-up ions upstream of Mercury’s magnetosphere. From these observations we infer properties of Mercury’s sodium exosphere and implications for the solar wind interaction with Mercury’s magnetosphere.

Selection of design parameters of diffusion barrier in a passive 222Rn sampler based on activated charcoal adsorption

International Nuclear Information System (INIS)

Wei Suxia

1992-01-01

A method concerning selection of design parameters of diffusion barrier in a passive 222 Rn sampler based on activated charcoal adsorption. The proper parameter value of diffusion barrier is obtained by means of linearization of 222 Rn adsorption versus the exposure time. Thus, the influence of temperature on measured results may be greatly decreased, and higher sensitivity of the detector may be maintained

Passive air sampler as a tool for long-term air pollution monitoring: Part 1. Performance assessment for seasonal and spatial variations

International Nuclear Information System (INIS)

Klanova, Jana; Kohoutek, Jiri; Hamplova, Lenka; Urbanova, Petra; Holoubek, Ivan

2006-01-01

The potential of passive air sampling devices (polyurethane foam disks) to assess the influence of local sources on the quality of the surrounding environment was investigated. DEZA Valasske Mezirici, a coal tar and mixed tar oils processing plant, and Spolana Neratovice, a chemical factory with the history of high production of organochlorinated pesticides (OCPs), were selected as the point sources of PAHs, and OCPs, respectively. Levels of PCBs, OCPs and PAHs were determined for all sampling sites and sampling periods. The study brought useful data about the air concentrations of POPs in the investigated regions. More important, it provided information on the transport and fate of POPs in the vicinity of local sources of contamination useful for the estimation of their influence. Very good capability of passive samplers to reflect temporal and spatial fluctuation in concentrations of persistent organic pollutants in the ambient air was confirmed which makes them applicable for monitoring on the local scale. - Passive air sampling techniques can indicate seasonal and spatial variations in the ambient concentrations of persistent organic compounds near point sources

The application of passive sampler (DGT technology for improved understanding of metal behaviour at a marine disposal site

Directory of Open Access Journals (Sweden)

Parker R.

2013-04-01

Full Text Available Metal behaviour and availability at a contaminated dredge material disposal site within UK waters has been investigated using Diffusive Gradient in Thin films (DGT passive sampling technology. Three stations representing contrasting history and presence of maintenance dredge disposal, including a control station outside the disposal site, have been studied and depth profiles of fluxes of different metals (Fe, Mn, Pb, Cu, Cd, Cr, Ni, Zn to the binding gel (Chelex 100 have been derived. Higher flux rates and shallower mobilisation of metals (Mn and Fe to the binding gel were observed at the disposal stations compared to the control station. Here we describe metal mobilization at different depths, linking the remobilization of Fe2+ and Mn2+ to the sediment (resupply of other heavy metals of interest with a focus on Cd, Ni and Pb and as they are on the Water Framework Directive (WFD list of priority substances and OSPAR list of priority pollutants. Results showed that Cd, Pb and Ni exhibited signs of resupply at the sediment-water interface (SWI. There was a potential increased mobilisation and source to the water column of Pb and Ni at the disposal site stations, but there was no Cd source, despite higher total loadings. This information has the potential to improve our current understanding of metal cycles at disposal sites. This work can be used as an indication of likely metal bioavailability and also assist in determining whether the sites act as sources or sinks of heavy metals. This information could assist disposal site monitoring and dredge material licensing.

Occurrence of Organic Wastewater Compounds in the Tinkers Creek Watershed and Two Other Tributaries to the Cuyahoga River, Northeast Ohio

Science.gov (United States)

Tertuliani, J.S.; Alvarez, D.A.; Furlong, E.T.; Meyer, M.T.; Zaugg, S.D.; Koltun, G.F.

2008-01-01

The U.S. Geological Survey - in cooperation with the Ohio Water Development Authority; National Park Service; Cities of Aurora, Bedford, Bedford Heights, Solon, and Twinsburg; and Portage and Summit Counties - and in collaboration with the Ohio Environmental Protection Agency, did a study to determine the occurrence and distribution of organic wastewater compounds (OWCs) in the Tinkers Creek watershed in northeastern Ohio. In the context of this report, OWCs refer to a wide range of compounds such as antibiotics, prescription and nonprescription pharmaceuticals, personal-care products, household and industrial compounds (for example, antimicrobials, fragrances, surfactants, fire retardants, and so forth) and a variety of other chemicals. Canisters containing polar organic integrative sampler (POCIS) and semipermeable membrane device (SPMD) media were deployed instream for a 28-day period in Mayand June 2006 at locations upstream and downstream from seven wastewater-treatment-plant (WWTP) outfalls in the Tinkers Creek watershed, at a site on Tinkers Creek downstream from all WWTP discharges, and at one reference site each in two nearby watersheds (Yellow Creek and Furnace Run) that drain to the Cuyahoga River. Streambed-sediment samples also were collected at each site when the canisters were retrieved. POCIS and SPMDs are referred to as 'passive samplers' because they sample compounds that they are exposed to without use of mechanical or moving parts. OWCs detected in POCIS and SPMD extracts are referred to in this report as 'detections in water' because both POCIS and SPMDs provided time-weighted measures of concentration in the stream over the exposure period. Streambed sediments also reflect exposure to OWCs in the stream over a long period of time and provide another OWC exposure pathway for aquatic organisms. Four separate laboratory methods were used to analyze for 32 antibiotic, 20 pharmaceutical, 57 to 66 wastewater, and 33 hydrophobic compounds. POCIS and

An upstream activation element exerting differential transcriptional activation on an archaeal promoter

DEFF Research Database (Denmark)

Peng, Nan; Xia, Qiu; Chen, Zhengjun

2009-01-01

S gene encoding an arabinose binding protein was characterized using an Sulfolobus islandicus reporter gene system. The minimal active araS promoter (P(araS)) was found to be 59 nucleotides long and harboured four promoter elements: an ara-box, an upstream transcription factor B-responsive element (BRE......), a TATA-box and a proximal promoter element, each of which contained important nucleotides that either greatly decreased or completely abolished promoter activity upon mutagenesis. The basal araS promoter was virtually inactive due to intrinsically weak BRE element, and the upstream activating sequence...... (UAS) ara-box activated the basal promoter by recruiting transcription factor B to its BRE. While this UAS ensured a general expression from an inactive or weak basal promoter in the presence of other tested carbon resources, it exhibited a strong arabinose-responsive transcriptional activation. To our...

Canadian upstream oil and gas industry profitability: Historical review and future perspectives [with executive summary

International Nuclear Information System (INIS)

1991-09-01

The profitability of the Canadian upstream oil and gas industry is examined by analyzing return on equity and return on capital invested. By all measures and interpretations, the upstream industry has been unprofitable since the mid-1980s; returns generated are far below the industry's own historical cost of capital, and are inadequate relative to other sectors of the Canadian economy and to international oil and gas companies. This poor profitability is attributed to such factors as: overly optimistic price forecasts and healthy cash flows generated in the early 1980s, which led to excess capital spending; poor returns on capital reflective of the physical limitations of the Western Canadian Sedimentary Basin; high capital and operating costs; and a high royalty burden imposed by provincial governments. The consequences of low profitability include inadequate returns to equity investors, a drop in spending on upstream services such as drilling and exploration, a reduced ability of the industry to generate employment, and an adverse effect on the economy of Alberta. Forecasts indicate that the upstream sector is extremely vulnerable to a scenario of relatively flat prices due to high and increasing operating costs and depletion charges, and the significant royalty payments that still are in effect. Little scope is foreseen for industry profitability to return to acceptable levels over the first half of the 1990s. Reduced royalties have the potential to make a significant contribution to improved profitability. 52 figs., 40 tabs

Thyroid hormone receptor binds to a site in the rat growth hormone promoter required for induction by thyroid hormone

International Nuclear Information System (INIS)

Koenig, R.J.; Brent, G.A.; Warne, R.L.; Larsen, P.R.; Moore, D.D.

1987-01-01

Transcription of the rat growth hormone (rGH) gene in pituitary cells is increased by addition of thyroid hormone (T3). This induction is dependent on the presence of specific sequences just upstream of the rGH promoter. The authors have partially purified T3 receptor from rat liver and examined its interaction with these rGH sequences. They show here that T3 receptor binds specifically to a site just upstream of the basal rGH promoter. This binding site includes two copies of a 7-base-pair direct repeat, the centers of which are separated by 10 base pairs. Deletions that specifically remove the T3 receptor binding site drastically reduce response to T3 in transient transfection experiments. These results demonstrate that T3 receptor can recognize specific DNA sequences and suggest that it can act directly as a positive transcriptional regulatory factor

Testing the sampling efficiency of a nuclear power station stack monitor

Energy Technology Data Exchange (ETDEWEB)

Stroem, L.H. [Instrumentinvest, Nykoeping (Sweden)

1997-08-01

The test method comprises the injection of known amounts of monodisperse particles in the stack air stream, at a suitable point upstream of the sampling installation. To find a suitable injection polls, the gas flow was mapped by means of a tracer gas, released in various points in the stack base. The resulting concentration distributions at the stack sampler level were observed by means of an array of gas detectors. An injection point that produced symmetrical distribution over the stack area, and low concentrations at the stack walls was selected for the particle tests. Monodisperse particles of 6, 10, and 19 {mu}m aerodynamic diameter, tagged with dysprosium, were dispersed in the selected injection point. Particle concentration at the sampler level was measured. The losses to the stack walls were found to be less than 10 %. The particle concentrations at the four sampler inlets were calculated from the observed gas distribution. The amount calculated to be aspirated into the sampler piping was compared with the quantity collected by the sampling train ordinary filter, to obtain the sampling line transmission efficiency. 1 ref., 2 figs.

Frequency effects of upstream wake and blade interaction on the unsteady boundary layer flow

International Nuclear Information System (INIS)

Kang, Dong Jin; Bae, Sang Su

2002-01-01

Effects of the reduced frequency of upstream wake on downstream unsteady boundary layer flow were simulated by using a Navier-Stokes code. The Navier-Stokes code is based on an unstructured finite volume method and uses a low Reynolds number turbulence model to close the momentum equations. The geometry used in this paper is the MIT flapping foil experimental set-up and the reduced frequency of the upstream wake is varied in the range of 0.91 to 10.86 to study its effect on the unsteady boundary layer flow. Numerical solutions show that they can be divided into two categories. One is so called the low frequency solution, and behaves quite similar to a Stokes layer. Its characteristics is found to be quite similar to those due to either a temporal or spatial wave. The low frequency solutions are observed clearly when reduced frequency is smaller than 3.26. The other one is the high frequency solution. It is observed for the reduced frequency larger than 7.24. It shows a sudden shift of the phase angle of the unsteady velocity around the edge of the boundary layer. The shift of phase angle is about 180 degree, and leads to separation of the boundary layer flow from corresponding outer flow. The high frequency solution shows the characteristics of a temporal wave whose wave length is half of the upstream frequency. This characteristics of the high frequency solution is found to be caused by the strong interaction between unsteady vortices. This strong interaction also leads to destroy of the upstream wake stripe inside the viscous sublayer as well as the buffer layer

Wake flow behaviour behind a smaller cylinder oscillating in the wake of an upstream stationary cylinder

Energy Technology Data Exchange (ETDEWEB)

Gao, Yangyang; Sun, Zhilin [Ocean College, Zhejiang University, Hangzhou 310058 (China); Tan, Danielle S [Maritime Research Centre, Nanyang Technological University, Singapore 639798 (Singapore); Yu, Dingyong [College of Engineering, Ocean University of China, 266100 (China); Tan, Soon Keat, E-mail: yygao@zju.edu.cn [Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 639798 (Singapore)

2014-04-01

The flow patterns around a cylinder oscillating freely in the wake of a larger cylinder upstream were investigated using the particle image velocimetry technique. The upstream cylinder was fixed at both ends while the downstream smaller cylinder was held by springs such that it was free to oscillate in the transverse direction. The flow patterns, amplitudes of oscillation and vortex shedding frequencies were compared with those of a single cylinder. In the presence of the upstream cylinder, the three parameters characterizing the oscillation response of the smaller cylinder—amplitude of oscillation, vortex shedding frequency and Reynolds stresses—were greatly reduced. While their magnitude increased with gap ratio, these three parameters were still smaller than the corresponding magnitudes for a single oscillating cylinder. The peak values of turbulence statistics such as Reynolds shear stress and normal stress behind the oscillating downstream cylinder were similarly reduced, and increased with gap ratios. (paper)

Endocrine disrupting activities of surface water associated with a West Virginia oil and gas industry wastewater disposal site

Science.gov (United States)

Kassotis, Christopher D.; Iwanowicz, Luke R.; Akob, Denise M.; Cozzarelli, Isabelle M.; Mumford, Adam; Orem, William H.; Nagel, Susan C.

2016-01-01

Currently, >95% of end disposal of hydraulic fracturing wastewater from unconventional oil and gas operations in the US occurs via injection wells. Key data gaps exist in understanding the potential impact of underground injection on surface water quality and environmental health. The goal of this study was to assess endocrine disrupting activity in surface water at a West Virginia injection well disposal site. Water samples were collected from a background site in the area and upstream, on, and downstream of the disposal facility. Samples were solid-phase extracted, and extracts assessed for agonist and antagonist hormonal activities for five hormone receptors in mammalian and yeast reporter gene assays. Compared to reference water extracts upstream and distal to the disposal well, samples collected adjacent and downstream exhibited considerably higher antagonist activity for the estrogen, androgen, progesterone, glucocorticoid and thyroid hormone receptors. In contrast, low levels of agonist activity were measured in upstream/distal sites, and were inhibited or absent at downstream sites with significant antagonism. Concurrent analyses by partner laboratories (published separately) describe the analytical and geochemical profiling of the water; elevated conductivity as well as high sodium, chloride, strontium, and barium concentrations indicate impacts due to handling of unconventional oil and gas wastewater. Notably, antagonist activities in downstream samples were at equivalent authentic standard concentrations known to disrupt reproduction and/or development in aquatic animals. Given the widespread use of injection wells for end-disposal of hydraulic fracturing wastewater, these data raise concerns for human and animal health nearby.

Endocrine disrupting activities of surface water associated with a West Virginia oil and gas industry wastewater disposal site.

Science.gov (United States)

Kassotis, Christopher D; Iwanowicz, Luke R; Akob, Denise M; Cozzarelli, Isabelle M; Mumford, Adam C; Orem, William H; Nagel, Susan C

2016-07-01

Currently, >95% of end disposal of hydraulic fracturing wastewater from unconventional oil and gas operations in the US occurs via injection wells. Key data gaps exist in understanding the potential impact of underground injection on surface water quality and environmental health. The goal of this study was to assess endocrine disrupting activity in surface water at a West Virginia injection well disposal site. Water samples were collected from a background site in the area and upstream, on, and downstream of the disposal facility. Samples were solid-phase extracted, and extracts assessed for agonist and antagonist hormonal activities for five hormone receptors in mammalian and yeast reporter gene assays. Compared to reference water extracts upstream and distal to the disposal well, samples collected adjacent and downstream exhibited considerably higher antagonist activity for the estrogen, androgen, progesterone, glucocorticoid and thyroid hormone receptors. In contrast, low levels of agonist activity were measured in upstream/distal sites, and were inhibited or absent at downstream sites with significant antagonism. Concurrent analyses by partner laboratories (published separately) describe the analytical and geochemical profiling of the water; elevated conductivity as well as high sodium, chloride, strontium, and barium concentrations indicate impacts due to handling of unconventional oil and gas wastewater. Notably, antagonist activities in downstream samples were at equivalent authentic standard concentrations known to disrupt reproduction and/or development in aquatic animals. Given the widespread use of injection wells for end-disposal of hydraulic fracturing wastewater, these data raise concerns for human and animal health nearby. Copyright © 2016 Elsevier B.V. All rights reserved.

Impacts of shape and height of upstream roof on airflow and pollutant dispersion inside an urban street canyon.

Science.gov (United States)

Huang, Yuan-Dong; He, Wen-Rong; Kim, Chang-Nyung

2015-02-01

A two-dimensional numerical model for simulating flow and pollutant dispersion in an urban street canyon is firstly developed using the FLUENT code and then validated against the wind tunnel results. After this, the flow field and pollutant dispersion inside an urban street canyon with aspect ratio W/H = 1 are examined numerically considering five different shapes (vaulted, trapezoidal, slanted, upward wedged, and downward wedged roofs) as well as three different roof height to building height ratios (Z H /H = 1/6, 1/3, and 1/2) for the upstream building roof. The results obtained reveal that the shape and height of an upstream roof have significant influences on flow pattern and pollutant distribution in an urban canyon. A large single clockwise vortex is generated in the canyon for the vaulted upstream roof at Z H /H = 1/6, 1/3, and 1/2, the trapezoidal and downward wedged roofs at Z H /H = 1/6 and 1/3, and the slanted and upward wedged roofs at Z H /H = 1/6, while a main clockwise vortex and a secondary counterclockwise vortex are established for the trapezoidal and downward wedged roofs at Z H /H = 1/2 and the slanted and upward wedged roofs at Z H /H = 1/3 and 1/2. In the one-vortex flow regime, the clockwise vortex moves upward and grows in size with increasing upstream roof height for the vaulted, trapezoidal, and downward wedged roofs. In the two-vortex flow regime, the size and rotational velocity of both upper clockwise and lower counterclockwise vortices increase with the upstream roof height for the slanted and upward wedged roofs. At Z H /H = 1/6, the pollution levels in the canyon are close among all the upstream roof shapes studied. At Z H /H = 1/3, the pollution levels in the canyon for the upward wedged roof and slanted roof are much higher than those for the vaulted, trapezoidal, and downward wedged roofs. At Z H /H = 1/2, the lowest pollution level appears in the canyon for the vaulted upstream roof, while

How to use Big Data technologies to optimize operations in Upstream Petroleum Industry

Directory of Open Access Journals (Sweden)

Abdelkader Baaziz

2013-12-01

Full Text Available “Big Data is the oil of the new economy” is the most famous citation during the three last years. It has even been adopted by the World Economic Forum in 2011. In fact, Big Data is like crude! It’s valuable, but if unrefined it cannot be used. It must be broken down, analyzed for it to have value. But what about Big Data generated by the Petroleum Industry and particularly its upstream segment? Upstream is no stranger to Big Data. Understanding and leveraging data in the upstream segment enables firms to remain competitive throughout planning, exploration, delineation, and field development.Oil & Gas Companies conduct advanced geophysics modeling and simulation to support operations where 2D, 3D & 4D Seismic generate significant data during exploration phases. They closely monitor the performance of their operational assets. To do this, they use tens of thousands of data-collecting sensors in subsurface wells and surface facilities to provide continuous and real-time monitoring of assets and environmental conditions. Unfortunately, this information comes in various and increasingly complex forms, making it a challenge to collect, interpret, and leverage the disparate data. As an example, Chevron’s internal IT traffic alone exceeds 1.5 terabytes a day.Big Data technologies integrate common and disparate data sets to deliver the right information at the appropriate time to the correct decision-maker. These capabilities help firms act on large volumes of data, transforming decision-making from reactive to proactive and optimizing all phases of exploration, development and production. Furthermore, Big Data offers multiple opportunities to ensure safer, more responsible operations. Another invaluable effect of that would be shared learning.The aim of this paper is to explain how to use Big Data technologies to optimize operations. How can Big Data help experts to decision-making leading the desired outcomes?Keywords:Big Data; Analytics

Investigating the Applicability of Upstream Detection Strategy at Pedestrian Signalised Crossings

Directory of Open Access Journals (Sweden)

Sitti A Hassan

2017-10-01

Full Text Available In the UK, the Puffin crossing has provision to extend pedestrian green time for those who take longer to cross. However, even at such a pedestrian friendly facility, the traffic signal control is usually designed to minimise vehicle delay while providing the crossing facility. This situation is rather contrary to the current policies to encourage walking. It is this inequity that has prompted the need to re-examine the traffic control of signalised crossings to provide more benefit to both pedestrians and vehicles. In this context, this paper explores the possibility of implementing an Upstream Detection strategy at a Puffin crossing to provide a user friendly crossing. The study has been carried out by simulating a mid-block Puffin crossing for various detector distances and a number of combinations of pedestrian and traffic flows. This paper presents the simulation results and recommends the situations at which Upstream Detection would be suitable.

Technical procedures for water resources: Volume 3, Environmental Field Program, Deaf Smith County Site, Texas: Final draft

International Nuclear Information System (INIS)

1987-08-01

To ensure that the environmental field program comprehensively addresses the issues and requirements of the project, a site study plan (SSP) has been prepared for Water Resources (ONWI, 1987). This technical procedure (TP) has been developed to implement the field program described in the Water Resources Site Study Plan. This procedure provides the general method for the field collection of water and sediment samples from playa lakes using an Alpha horizontal type sampler or equivalent or a peristaltic pump for water and a KB-coring devise or ponar grab for sediments. The samples will be preserved and then shipped to a laboratory for analysis. The water quality and sediment samples will be collected as part of the surface-water quality field study described in the Site Plan for Water Resources. 15 refs., 5 figs., 3 tabs

Upstream pumping of radial lip seals by tangentially deforming, rough seal surfaces

NARCIS (Netherlands)

Bavel, van P.G.M.; Ruijl, T.A.M.; Leeuwen, van H.J.; Muijderman, E.A.

1996-01-01

This paper aims at a theoretical explanation of the following two experimental observations of radial lip seals: fluid film formation and upstream pumping action. The origins of these observations are still poorly understood. A hydrodynamic analysis is presented for the fully flooded contact zone of

In vitro transcription in the presence of DNA oligonucleotides can generate strong anomalous initiation sites.

Science.gov (United States)

Chow, C W; Clark, M P; Rinaldo, J E; Chalkley, R

1996-03-01

In the present study, we have explored an unexpected observation in transcription initiation that is mediated by single-stranded oligonucleotides. Initially, our goal was to understand the function of different upstream regulatory elements/initiation sites in the rat xanthine dehydrogenase/oxidase (XDH/XO) promoter. We performed in vitro transcription with HeLa nuclear extracts in the presence of different double-stranded oligonucleotides against upstream elements as competitors. A new and unusual transcription initiation site was detected by primer extension. This new initiation site maps to the downstream region of the corresponding competitor. Subsequent analyses have indicated that the induction of a new transcription initiation site is anomalous which is due to the presence of a small amount of single-stranded oligonucleotide in the competitor. We found that this anomalous initiation site is insensitive to the orientation of the promoter and requires only a small amount of single-stranded oligonucleotide (< 2-fold molar excess relative to template). We surmise that a complementary interaction between the single-stranded oligonucleotide and transiently denatured promoter template may be responsible for this sequence-specific transcription initiation artifact. To study the regulation of transcription initiation by in vitro transcription approaches, we propose that one should probe the effect of removing transacting factors by adding an excess of a cognate oligonucleotide which does not bear exact sequence identity to the template.

Site characterization in connection with the low level defense waste management site in Area 5 of the Nevada Test Site, Nye County, Nevada. Final report

International Nuclear Information System (INIS)

Case, C.; Davis, J.; French, R.; Raker, S.

1984-09-01

The Site Characterization Report for the Defense Low Level Waste Management Site (RWMS) in Area 5 of the Nevada Test Site deals with the FY80-FY84 DRI activities. The areas that have been studied include geology, hydrology, unsaturated flow, soil and soil water chemistry, flood hazard, and economics-demographics. During this time the site characterization effort focussed on the following items as requested by NVO: geological and hydrological limitations to greater depth disposal of radioactive waste; potential for tectonic, seismic or volcanic activity (extent and frequency which these processes significantly affect the ability of the disposal operation to meet performance objectives); the possibility of groundwater intrusion into the waste zone, and its significance; topography of the RWMS with significance to drainage and flood potential (100-year flood plain, coastal high-hazard area or wetland); upstream drainage which may require modification to avoid erosion; population growth and future development; and the presence or absence of economically significant natural resources which, if exploited, would result in failure to meet performance objectives. The items mentioned above are dealt with in the description of activities and results in the body of the report. Extensive references, 32 figures, 20 tables

Comparison of the CAS-POL and IOM samplers for determining the knockdown efficiencies of water sprays on float coal dust.

Science.gov (United States)

Seaman, Clara E; Shahan, Michael R; Beck, Timothy W; Mischler, Steven E

2018-03-01

Float coal dust, generated by mining operations, is distributed throughout mine airways by ventilating air designed to purge gases and respirable dust. Float coal dust poses an explosion hazard in the event of a methane ignition. Current regulation requires the application of inert rock dust in areas subjected to float coal dust in order to mitigate the hazard. An alternate method using water sprays, which have been effective in controlling respirable dust hazards, has been proposed as a way to control float coal dust generated on longwall faces. However, the knockdown efficiency of the proposed water sprays on float coal dust needs to be verified. This study used gravimetric isokinetic Institute of Occupational Medicine (IOM) samplers alongside a real-time aerosol monitor (Cloud Aerosol Spectrometer with polarization; CAS-POL) to study the effects of spray type, operating pressure, and spray orientation on knockdown efficiencies for seven different water sprays. Because the CAS-POL has not been used to study mining dust, the CAS-POL measurements were validated with respect to the IOM samplers. This study found that the CAS-POL was able to resolve the same trends measured by the IOM samplers, while providing additional knockdown information for specific particle size ranges and locations in the test area. In addition, the CAS-POL data was not prone to the same process errors, which may occur due to the handling of the IOM filter media, and was able to provide a faster analysis of the data after testing. This study also determined that pressure was the leading design criteria influencing spray knockdown efficiency, with spray type also having some effect and orientation having little to no effect. The results of this study will be used to design future full-scale float coal dust capture tests involving multiple sprays, which will be evaluated using the CAS-POL.

Automated lake-wide erosion predictions and economic damage calculations upstream of the Moses-Saunders power dam

International Nuclear Information System (INIS)

Zuzek, P.; Baird, W.F.; International Joint Commission, Ottawa, ON

2008-01-01

This presentation discussed an automated flood and erosion prediction system designed for the upstream sections of the Moses-Saunders power dam. The system included a wave prediction component along with 3-D maps, hourly run-ups, geographic information system (GIS) tools and a hazard analysis tool. Parcel, reach, township, and county databases were used to populate the system. The prediction system was used to develop detailed study sites of shore units in the study area. Shoreline classes included sand and cohesive buffs, low banks, coarse beaches, and cobble or boulder lags. Time series plots for Lake Ontario water and wave levels were presented. Great Lakes ice cover data were also included in the system as well as erosion predictions from 1961 to 1995. The system was also used to develop bluff recession equations and cumulative recession analyses for different regulation plans. Cumulative bluff recession and protection requirements were outlined. Screenshots of the flood and erosion prediction system interface were also included. tabs., figs

(LBA-and-WRM)-based DBA scheme for multi-wavelength upstream transmission supporting 10 Gbps and 1 Gbps in MAN

Science.gov (United States)

Zhang, Yuchao; Gan, Chaoqin; Gou, Kaiyu; Xu, Anni; Ma, Jiamin

2018-01-01

DBA scheme based on Load balance algorithm (LBA) and wavelength recycle mechanism (WRM) for multi-wavelength upstream transmission is proposed in this paper. According to 1 Gbps and 10 Gbps line rates, ONUs are grouped into different VPONs. To facilitate wavelength management, resource pool is proposed to record wavelength state. To realize quantitative analysis, a mathematical model describing metro-access network (MAN) environment is presented. To 10G-EPON upstream, load balance algorithm is designed to ensure load distribution fairness for 10G-OLTs. To 1G-EPON upstream, wavelength recycle mechanism is designed to share remained wavelengths. Finally, the effectiveness of the proposed scheme is demonstrated by simulation and analysis.

Application of Frequency of Detection Methods in Design and Optimization of the INL Site Ambient Air Monitoring Network

Energy Technology Data Exchange (ETDEWEB)

Rood, Arthur S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sondrup, A. Jeffrey [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-11-01

This report presents an evaluation of a hypothetical INL Site monitoring network and the existing INL air monitoring network using frequency of detection methods. The hypothetical network was designed to address the requirement in 40 CFR Part 61, Subpart H (2006) that “emissions of radionuclides to ambient air from U.S. DOE facilities shall not exceed those amounts that would cause any member of the public to receive in any year an effective dose equivalent exceeding 10 mrem/year.” To meet the requirement for monitoring only, “radionuclide releases that would result in an effective dose of 10% of the standard shall be readily detectable and distinguishable from background.” Thus, the hypothetical network consists of air samplers placed at residence locations that surround INL and at other locations where onsite livestock grazing takes place. Two exposure scenarios were used in this evaluation: a resident scenario and a shepherd/rancher scenario. The resident was assumed to be continuously present at their residence while the shepherd/rancher was assumed to be present 24-hours at a fixed location on the grazing allotment. Important radionuclides were identified from annual INL radionuclide National Emission Standards for Hazardous Pollutants reports. Important radionuclides were defined as those that potentially contribute 1% or greater to the annual total dose at the radionuclide National Emission Standards for Hazardous Pollutants maximally exposed individual location and include H-3, Am-241, Pu-238, Pu 239, Cs-137, Sr-90, and I-131. For this evaluation, the network performance objective was set at achieving a frequency of detection greater than or equal to 95%. Results indicated that the hypothetical network for the resident scenario met all performance objectives for H-3 and I-131 and most performance objectives for Cs-137 and Sr-90. However, all actinides failed to meet the performance objectives for most sources. The shepherd/rancher scenario showed

Low power consumption O-band VCSEL sources for upstream channels in PON systems

DEFF Research Database (Denmark)

Vegas Olmos, Juan José; Rodes Lopez, Roberto; Tafur Monroy, Idelfonso

2012-01-01

This paper presents an experimental validation of a low power optical network unit employing vertical-cavity surface-emitting lasers as upstream sources for passive optical networks with an increased power budget, enabling even larger splitting ratios....

Explosion Clad for Upstream Oil and Gas Equipment

Science.gov (United States)

Banker, John G.; Massarello, Jack; Pauly, Stephane

2011-01-01

Today's upstream oil and gas facilities frequently involve the combination of high pressures, high temperatures, and highly corrosive environments, requiring equipment that is thick wall, corrosion resistant, and cost effective. When significant concentrations of CO2 and/or H2S and/or chlorides are present, corrosion resistant alloys (CRA) can become the material of choice for separator equipment, piping, related components, and line pipe. They can provide reliable resistance to both corrosion and hydrogen embrittlement. For these applications, the more commonly used CRA's are 316L, 317L and duplex stainless steels, alloy 825 and alloy 625, dependent upon the application and the severity of the environment. Titanium is also an exceptional choice from the technical perspective, but is less commonly used except for heat exchangers. Explosion clad offers significant savings by providing a relatively thin corrosion resistant alloy on the surface metallurgically bonded to a thick, lower cost, steel substrate for the pressure containment. Developed and industrialized in the 1960's the explosion cladding technology can be used for cladding the more commonly used nickel based and stainless steel CRA's as well as titanium. It has many years of proven experience as a reliable and highly robust clad manufacturing process. The unique cold welding characteristics of explosion cladding reduce problems of alloy sensitization and dissimilar metal incompatibility. Explosion clad materials have been used extensively in both upstream and downstream oil, gas and petrochemical facilities for well over 40 years. The explosion clad equipment has demonstrated excellent resistance to corrosion, embrittlement and disbonding. Factors critical to insure reliable clad manufacture and equipment design and fabrication are addressed.

Explosion Clad for Upstream Oil and Gas Equipment

International Nuclear Information System (INIS)

Banker, John G.; Massarello, Jack; Pauly, Stephane

2011-01-01

Today's upstream oil and gas facilities frequently involve the combination of high pressures, high temperatures, and highly corrosive environments, requiring equipment that is thick wall, corrosion resistant, and cost effective. When significant concentrations of CO 2 and/or H 2 S and/or chlorides are present, corrosion resistant alloys (CRA) can become the material of choice for separator equipment, piping, related components, and line pipe. They can provide reliable resistance to both corrosion and hydrogen embrittlement. For these applications, the more commonly used CRA's are 316L, 317L and duplex stainless steels, alloy 825 and alloy 625, dependent upon the application and the severity of the environment. Titanium is also an exceptional choice from the technical perspective, but is less commonly used except for heat exchangers. Explosion clad offers significant savings by providing a relatively thin corrosion resistant alloy on the surface metallurgically bonded to a thick, lower cost, steel substrate for the pressure containment. Developed and industrialized in the 1960's the explosion cladding technology can be used for cladding the more commonly used nickel based and stainless steel CRA's as well as titanium. It has many years of proven experience as a reliable and highly robust clad manufacturing process. The unique cold welding characteristics of explosion cladding reduce problems of alloy sensitization and dissimilar metal incompatibility. Explosion clad materials have been used extensively in both upstream and downstream oil, gas and petrochemical facilities for well over 40 years. The explosion clad equipment has demonstrated excellent resistance to corrosion, embrittlement and disbonding. Factors critical to insure reliable clad manufacture and equipment design and fabrication are addressed.

Suppression of HPV-16 late L1 5′-splice site SD3632 by binding of hnRNP D proteins and hnRNP A2/B1 to upstream AUAGUA RNA motifs

Science.gov (United States)

Li, Xiaoze; Johansson, Cecilia; Glahder, Jacob; Mossberg, Ann-Kristin; Schwartz, Stefan

2013-01-01

Human papillomavirus type 16 (HPV-16) 5′-splice site SD3632 is used exclusively to produce late L1 mRNAs. We identified a 34-nt splicing inhibitory element located immediately upstream of HPV-16 late 5′-splice site SD3632. Two AUAGUA motifs located in these 34 nt inhibited SD3632. Two nucleotide substitutions in each of the HPV-16 specific AUAGUA motifs alleviated splicing inhibition and induced late L1 mRNA production from episomal forms of the HPV-16 genome in primary human keratinocytes. The AUAGUA motifs bind specifically not only to the heterogeneous nuclear RNP (hnRNP) D family of RNA-binding proteins including hnRNP D/AUF, hnRNP DL and hnRNP AB but also to hnRNP A2/B1. Knock-down of these proteins induced HPV-16 late L1 mRNA expression, and overexpression of hnRNP A2/B1, hnRNP AB, hnRNP DL and the two hnRNP D isoforms hnRNP D37 and hnRNP D40 further suppressed L1 mRNA expression. This inhibition may allow HPV-16 to hide from the immune system and establish long-term persistent infections with enhanced risk at progressing to cancer. There is an inverse correlation between expression of hnRNP D proteins and hnRNP A2/B1 and HPV-16 L1 production in the cervical epithelium, as well as in cervical cancer, supporting the conclusion that hnRNP D proteins and A2/B1 inhibit HPV-16 L1 mRNA production. PMID:24013563

Exploring Patterns of Upstream Internationalization: The Role of Home-region ‘Stickiness’

NARCIS (Netherlands)

A.R. Muller (Allan); R.J.M. van Tulder (Rob)

2005-01-01

textabstractRecent work has emphasized the importance of regional strategies downstream, adding new depth to the debate on ‘globalization’. This paper adds to the debate by exploring the regional dimension upstream for a sample of Triad-based Fortune 500 firms. We find support for our hypothesis

Effect of longitudinal and transverse vibrations of an upstream square cylinder on vortex shedding behind two inline square cylinders

International Nuclear Information System (INIS)

Patil, Pratish P; Tiwari, Shaligram

2009-01-01

The characteristics of unsteady wakes behind a stationary square cylinder and another upstream vibrating square cylinder have been investigated numerically with the help of a developed computational code. The effect of longitudinal as well as transverse vibrations of the upstream cylinder is studied on the coupled wake between the two cylinders, which is found to control the vortex shedding behavior behind the downstream stationary cylinder. Computations are carried out for a fixed value of Reynolds number (Re = 200) and three different values of excitation frequencies of the upstream cylinder, namely less than, equal to and greater than the natural frequency of vortex shedding corresponding to flow past a stationary square cylinder. The vortex shedding characteristics of the unsteady wakes behind the vibrating and stationary cylinders are found to differ significantly for longitudinal and transverse modes of vibration of the upstream cylinder. The wake of the downstream stationary cylinder is found to depict a synchronization behavior with the upstream cylinder vibration. The spacing between the two cylinders has been identified to be the key parameter influencing the synchronization phenomenon. The effect of cylinder spacing on the wake synchronization and the hydrodynamic forces has been examined. In addition, a comparison of the drag forces for flow past transversely vibrating square and circular cylinders for similar amplitudes and frequencies of cylinder vibration has been presented while employing the tested computational code.

Investigation of ground-water contamination at a drainage ditch, Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, 2005–06

Science.gov (United States)

Vroblesky, Don A.; Casey, Clifton C.

2007-01-01

The U.S. Geological Survey, in cooperation with the Naval Facilities Engineering Command Southeast, used newly developed sampling methods to investigate ground-water contamination by chlorobenzenes beneath a drainage ditch on the southwestern side of Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, during 2005-06. The drainage ditch, which is a potential receptor for ground-water contaminants from Installation Restoration Site 4, intermittently discharges water to Corpus Christi Bay. This report uses data from a new type of pore-water sampler developed for this investigation and other methods to examine the subsurface contamination beneath the drainage ditch. Analysis of ground water from the samplers indicated that chlorobenzenes (maximum detected concentration of 160 micrograms per liter) are present in the ground water beneath the ditch. The concentrations of dissolved oxygen in the samples (less than 0.05-0.4 milligram per liter) showed that the ground water beneath and near the ditch is anaerobic, indicating that substantial chlorobenzene biodegradation in the aquifer beneath the ditch is unlikely. Probable alternative mechanisms of chlorobenzene removal in the ground water beneath the drainage ditch include sorption onto the organic-rich sediment and contaminant depletion by cattails through uptake, sorption, and localized soil aeration.

Water-soluble ions in nano/ultrafine/fine/coarse particles collected near a busy road and at a rural site

International Nuclear Information System (INIS)

Lin, C.-C.; Chen, S.-J.; Huang, K.-L.; Lee, W.-J.; Lin, W.-Y.; Liao, C.-J.; Chaung, H.-C.; Chiu, C.-H.

2007-01-01

This study investigated water-soluble ions in the sized particles (particularly nano (PM 0.01-0.056 )/ultrafine (PM 0.01-0.1 )) collected using MOUDI and Nano-MOUDI samplers near a busy road site and at a rural site. The analytical results demonstrate that nano and coarse particles exhibited the highest (16.3%) and lowest (8.37%) nitrate mass ratios, respectively. The mass ratio of NO 3 - was higher than that of SO 4 2- in all the sized particles at the traffic site. The secondary aerosols all displayed trimodal distributions. The aerosols in ultrafine particles collected at the roadside site exhibited Aitken mode distributions indicating they were of local origin. This finding was not observed for those ultrafine particles collected at the rural site. The mass median diameters (MMDs) of the nano, ultrafine, and fine particles were smaller at the traffic site than at the rural site, possibly related to the contribution of mobile engine emissions. - NO 3 - > SO 4 2- in mass ratio, different from common observations in rural areas, was found in (particularly the nano) traffic-associated particles

The role of the ionosphere in coupling upstream ULF wave power into the dayside magnetosphere

International Nuclear Information System (INIS)

Engebretson, M.J.; Cahill, L.J. Jr.; Arnoldy, R.L.; Anderson, B.J.; Rosenberg, T.J.; Carpenter, D.L.; Inan, U.S.; Eather, R.H.

1991-01-01

A series of recent studies of Pc 3 magnetic pulsations in the dayside outer magnetosphere has given new insights into the possible mechanisms of entry of ULF wave power into the magnetosphere from a bow shock related upstream source. In this paper, the authors first review many of these new observational results by presenting a comparison of data from two 10-hour intervals on successive days in April 1986 and then present a possible model for transmission of pulsation signals from the magnetosheath into the dayside magnetosphere. Simultaneous multi-instrument observations at South Pole Station, located below the cusp/cleft ionosphere near local noon, magnetic field observations by the AMPTE CCE satellite in the dayside outer magnetosphere, and upstream magnetic field observations by the IMP 8 satellite show clear interplanetary magnetic field field magnitude control of dayside resonant harmonic pulsations and band-limited very high latitude pulsations, as well as pulsation-modulated precipitation of what appear to be magnetosheath/boundary layer electrons. They believe that this modulated precipitation may be responsible for the propagation of upstream wave power in the Pc 3 frequency band into the high-latitude ionosphere, from whence it may be transported throughout the dayside outer magnetosphere by means of an ionospheric transistor. In this model, modulations in ionospheric conductivity caused by cusp/cleft precipitation cause varying ionospheric currents with frequency spectra determined by the upstream waves; these modulations will be superimposed on the Birkeland currents, which close via these ionospheric currents. Modulated region 2 Birkeland currents will in turn provide a narrow-band source of wave energy to a wide range of dayside local times in the outer magnetosphere

The effects of rice canopy on the air-soil exchange of polycyclic aromatic hydrocarbons and organochlorine pesticides using paired passive air samplers.