The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
J D Rouse - One of the best experts on this subject based on the ideXlab platform.
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chlorinated hydrocarbon concentrations in plasma of the lake erie water snake nerodia sipedon insularum and northern water snake nerodia sipedon sipedon from the great lakes basin in 1998
Archives of Environmental Contamination and Toxicology, 2000Co-Authors: Christine A Bishop, J D RouseAbstract:From the Great Lakes basin, concentrations of 59 congener-specific polychlorinated biphenyls (PCBs) and 14 organochlorine pesticides were measured in blood plasma of northern water snake (Nerodia sipedon sipedon) and Lake Erie water snake (Nerodia sipedon insularum), which is endangered in Canada. In 1998, four male adult Lake Erie water snakes were sampled from Pelee Island, western Lake Erie; four male northern water snakes were sampled at Little Lake, about 20 km north of Parry Sound in central Ontario; and four adult gravid female northern water snakes were sampled from Garden Island, eastern Lake Ontario. The blood plasma was pooled by site for a total of three samples analyzed. The Pelee Island sample from male Lake Erie water snakes contained less than half the lipid concentration (0.349%) than samples from the other sites, but it was the most contaminated with PCBs, even on a wet weight basis. Summed concentration of individual PCBs in the Pelee Island sample was 167 ng/g (wet weight), which was 14-fold higher than the next most contaminated sample, which was from Little Lake. The plasma sample from Little Lake contained 12 ng/g (WW) and was four times more contaminated with PCBs than the sample from female snakes from Garden Island, Lake Ontario. Organochlorine pesticide concentrations in plasma were relatively similar among sites. None of the pesticides was found above trace concentrations (0.1-0.9 ng/g) except pp'-DDE, which occurred at 2-5 ng/g among sites. PCB congener patterns in the Lake Erie water snakes were compared to PCB patterns in plasma of common snapping turtle (Chelydra serpentina serpentina) from Lake Ontario, herring gull eggs (Larus argentatus) from western Lake Erie, and mudpuppy eggs (Necturus maculosus) from the Detroit River. The PCB patterns in water snake and herring gull sample were most similar, followed by the pattern in snapping turtle plasma. The presence of more lower-chlorinated chlorobiphenyls in the mudpuppy eggs relative to the other species made this sample distinct from the water snake, gull, and turtle.
Ying Chen - One of the best experts on this subject based on the ideXlab platform.
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Design of novel high pressure-resistant hydrothermal fluid sample valve
Chinese Journal of Mechanical Engineering (English Edition), 2008Co-Authors: Wenhua Liu, Y. Xie, Ce Yang, S. Wu, Ying ChenAbstract:Sampling study is an effective exploration method, but the most extreme environments of hydrothermal vents pose considerable engineering challenges for sampling hydrothermal fluids. Moreover, traditional Sampler systems with sample valves have difficulty in maintaining samples in situ pressure. However, decompression changes have effect on microorganisms sensitive to such stresses. To address the technical difficulty of collecting samples from hydrothermal vents, a new bidirectional high pressure-resistant sample valve with balanced poppet was designed. The sample valve utilizes a soft high performance plastic 'PEEK' as poppet. The poppet with inapposite dimension is prone to occur to plastic deformation or rupture for high working pressure in experiments. To address this issue, based on the finite element model, simulated results on stress distribution of the poppet with different structure parameters and preload spring force were obtained. The static axial deformations on top of the poppet were experimented. The simulated results agree with the experimental results. The new sample valve seals well and it can withstand high working pressure.
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Optimal design of a novel hydrothermal fluid Sampler
Proceedings of the ISOPE Ocean Mining Symposium, 2005Co-Authors: Wenhua Liu, G. Shen, Ce Yang, Ying ChenAbstract:Discovery of deep sea hydrothermal vents is one of the most important achievements in the underwater scientific history of last century. The study and exploration of hydrothermal vents are very significant worldwide. Sampling hydrothermal fluid of high purity is an important way to ensure the study of hydrothermal vent successfully. A novel Sampler of hydrothermal fluid is proposed and discussed in the paper. A new instrument is constructed of inert titanium, which is gas-tight to 70 Mpa and can be used to sample fluids with temperature up to 400°C. Sampling hydrothermal fluid of high purity means that the temperature and pressure of fluid sampled by the Sampler is the same as in the vent area. Maintaining high pressure can be realized by pressure compensator. The structure of double cylinders is designed for the Sampler to insulate the heat transfer from inside of the Sampler to the sea water, while its interlayer is evacuated to be filled with insulating materials. Taking the dimension of Sampler into consideration, a finite element analysis is used for optimizing its dimension. The simulation and experiments show that the novel Sampler can be used to collect samples from the extreme-pressure vents environments. Copyright © 2005 by The International Society of Offshore and Polar Engineers.
Garon C. Smith - One of the best experts on this subject based on the ideXlab platform.
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High-volume PUF versus low-volume PUF sampling comparison for collecting gas plus particulate polycyclic aromatic hydrocarbons
Aerosol Science and Technology, 2004Co-Authors: Tony J Ward, Garon C. SmithAbstract:A yearlong sampling program for PM2.5 and semivolatile organic compounds (SVOCs) was conducted in 2000/2001 in Missoula, Montana by The University of Montana, Department of Chemistry. One aspect of this program was to investigate the SVOC fraction of the Missoula Valley PM2.5 by evaluating a Federal Reference Method (FRM) PM2.5 Sampler modified with Polyurethane Foam (PUF) sorbent (PM2.5 PUF). In addition, a method of comparison was made between sampling for SVOCs using this modified PM2.5 PUF Sampler and in using a high-volume PUF Sampler (Hi-vol PUF) following EPA protocol. For this comparison, the quartz filter and PUF plugs were extracted together in the analysis of the PM2.5 PUF and Hi-vol PUF samples, respectively. Results of this program showed that a trade off between Hi-vol PUF sampling and PM2.5 PUF sampling was revealed. During the same sampling periods, the PM2.5 PUF measured more of the lighter (smaller molecular weight) SVOCs in a side-by-side comparison with the Hi-vol PUF Sampler, with much less volume of sample collected due to a lower flow rate. However, each 24 h Hi-vol PUF sample run provided enough material on which to conduct an SVOC analysis, avoiding the need to aggregate samples (or longer sampling periods) to meet analytical detection limits. In addition, the results presented here also raise important questions about the efficiency of existing PUF Samplers (when using quartz filters and PUF sorbent media) in the accurate measurement of lower molecular weight particle and gas-phase SVOCs.
S Kaneko - One of the best experts on this subject based on the ideXlab platform.
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Development of a multibottle gas-tight fluid Sampler WHATS II for Japanese submersibles/ROVs
Geofluids, 2006Co-Authors: Shozo Saegusa, F Nakagawa, Urumu Tsunogai, S KanekoAbstract:This paper summarizes the design and performance of our recently developed gas-tight fluid Sampler WHATS II, especially designed to collect seafloor venting gas-rich fluid from submersibles/remotely operated vehicles (ROVs). It consists of four 150-cm(3) stainless steel sample cylinders, eight ball valves, a motor-driven arm, a rail, a peristaltic pump, a control unit, and a flexible Teflon tube connected to a titanium inlet tube. All the parts have been designed to be used at undersea as deep as 4000 m. The motor-driven arm on the rail can open and close each of the four cylinders. By pumping out distilled water that has filled an open cylinder and the dead spaces of the Sampler, we can fill the cylinder with sample fluid. WHATS II can take a maximum of four different gas-tight samples in a series. The whole operation can be arranged from the cabin, etc., of a submersible/ROV. Use of only one motor to operate eight valves makes the Sampler small, light (21 kg in sea water), and easy to handle. In addition, the Sampler is able to collect an almost uncontaminated gas-tight sample from the seafloor. To date, the Sampler has been used in more than 90 dive surveys by Japanese submersibles/ROVs, including Shinkai 2000, Shinkai 6500, and Hyper Dolphin, with a success rate of > 90%.
Sergey A. Grinshpun - One of the best experts on this subject based on the ideXlab platform.
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Development and evaluation of a new personal Sampler for culturable airborne microorganisms
Atmospheric Environment, 2002Co-Authors: Igor E. Agranovski, Victoria Agranovski, Klaus Willeke, Tiina Reponen, Sergey A. GrinshpunAbstract:The objective of this study was to develop a new personal Sampler for viable airborne microorganisms and to evaluate its performance under controlled laboratory conditions and in a field. In the Sampler, air is bubbled through a porous medium submerged in a liquid layer, as has earlier been demonstrated to be highly efficient for air purification. The prototype had the physical collection efficiency >95% for particles >0.32μm in aerodynamic diameter during 8h of continuous operation. The pressure drop across the Sampler was below 1700Pa, much lower than that of most conventional bioaerosol Samplers. The collection liquid losses due to evaporation and aerosolization did not exceed 18% in 8h and the culturability of sampled microorganisms remained high: the recovery rate of stress-sensitive gram-negative P. fluorescens bacteria was 61±20%; for stress-resistant B. subtilis bacteria and A. versicolor fungal spores it was 95±9% and 97±6%, respectively. Six identical personal Samplers were tested simultaneously on a simplified human manikin in an office environment. The culturable microbial concentration data obtained during 2, 4 and 8-h sampling were not affected by the sampling time. Inter-sample variation did not exceed 30%. The laboratory and field evaluations have demonstrated that the new Sampler is capable of long-term personal sampling of airborne culturable microorganisms. The estimation of the detection limits has indicated that the Sampler is capable of monitoring microbial exposure in the environments with the bacterial concentrations above 15CFU/m3and fungal concentrations above 5CFU/m3when using a sampling time of 8h. Copyright © 2002 Elsevier Science Ltd.
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Inlet characteristics of bioaerosol Samplers
Journal of Aerosol Science, 1994Co-Authors: Sergey A. Grinshpun, Aino Nevalainen, Ching-wen Chang, Klaus WillekeAbstract:The inlet sampling characteristics of several commercial bioaerosol Samplers operating in indoor and outdoor environments have been analyzed by use of available and newly developed equations for sampling efficiency. With a focus on the physical aspects of sampling efficiency, the aspiration and transmission efficiencies have been calculated for the bioaerosol particle size range 1–30 μm, which represents single bacteria, bacteria aggregates, bacteria carrying particles, fungal spores, yeast, and pollen. Under certain sampling conditions, the bioaerosol concentration was found to be significantly over- or underestimated. At wind velocities between 0 and 500 cm s−1, calculations show that the AGI-30 would sample 1–10 μm particles with an inlet sampling efficiency of 20–100%. The entrance efficiency of the 6-stage Andersen viable Sampler is 90–150% when sampling isoaxially with respect to horizontal aerosol flows, and 8–100% when oriented vertically at a right angle to the horizontal aerosol flow. For the Burkard portable air Sampler, an even wider range of deviation may occur. The bioaerosol Samplers used for large particles such as pollen are even less accurate: e.g. 10 times the ambient concentration of Lycopodium spores has been calculated to be aspirated by the Lanzoni Sampler when operated at 0.5 1 min−1 facing the wind at wind velocity of about 500 cm s−1. The actual bioaerosol concentration can be calculated from the measured data by use of the indicated procedures. The sampling efficiency graphs presented can be used to bracket the sampling conditions that enable the investigator to avoid or minimize significant sampling biases for each Sampler. The findings can also be used for the design of new Samplers or for improving commercially available Samplers.
