0D KINETIC MODEL: APPLIED TO SF6

This work is related to the chemical kinetics modelling of plasma during extinction. A zero-dimensional model (0D) has been developed. Two hypotheses were used: (A) a constant pressure or (B) a constant mass density. Three initial data categories are generally required for the model: (1) the chemical reactions that govern the kinetic scheme, (2) the chemical composition at the local thermodynamic equilibrium (LTE) and (3) a law of temperature decay as a function of time representing the cooling rate. The developed model is presented and applied to SF6, gas commonly used in high voltage circuit breakers (HVCB), in order to be validated. We present the evolution of the species during the temperature decay for several cooling rates. The results give the evolution of species densities and the departures from equilibrium according to the cooling rate. Consideration of SFx molecules is essential in order to avoid erroneous interpretations

Influence of Copper Vapors in SF6 Plasma

In this study a theoretical approach allows estimating the ablation mass flux of copper from a corrected Hertz-Knudsen flux. The influence of the copper vapours coming from the anode electrode to an SF6 plasma is studied in a simplified 2D configuration. Depending on the plasma pressure an ablation or a diffusion state is considered. The amount of copper versus time is presented. An RMS current I=10 kA is applied leading at t=10 ms to an amount of copper equal to 0.55 mg. The vapours change the plasma properties mainly the electrical conductivity and radiation and so the plasma behaviour. At time t=5 ms the electrode erosion leads to a copper plasma. This simple case shows the necessity to well consider the copper erosion in plasma modelling as in High Voltage Circuit Breaker (HVCB) where higher current are considered

Technology, Labor Interests and the Law: Some Fundamental Points and Problems

The symposium of which this essay is a part deals with technology and law with particular reference to the interests of workers. Perhaps needless to say but nonetheless important, each of the three topics- technology, law and worker interests-has had a long history of controversy about factual or positive and normative considerations

Antithrombotic therapy in patients receiving saphenous vein coronary artery bypass grafts: a protocol for a systematic review and network meta-analysis.

INTRODUCTION: The current evidence for the prevention of saphenous vein graft failure (SVGF) after coronary artery bypass graft (CABG) surgery consists of direct head-to-head comparison of treatments (including placebo) in randomised-controlled trials (RCTs) and observational studies. However, summarising the evidence using traditional pairwise meta-analyses does not allow the inclusion of data from treatments that have not been compared head to head. Exclusion of such comparisons could impact the precision of pooled estimates in a meta-analysis. Hence, to address the challenge of whether aspirin alone or in addition to another antithrombotic agent is a more effective regimen to improve SVG patency, a network meta-analysis (NMA) is necessary. The objectives of this study are to synthesise the available evidence on antithrombotic agents (or their combination) and estimate the treatment effects among direct and indirect treatment comparisons on SVGF and major adverse cardiovascular events, and to generate a treatment ranking according to their efficacy and safety outcomes. METHODS: We will perform a systematic review of RCTs evaluating antithrombotic agents in patients undergoing CABG. A comprehensive English literature search will be conducted using electronic databases and grey literature resources to identify published and unpublished articles. Two individuals will independently and in duplicate screen potential studies, assess the eligibility of potential studies and extract data. Risk of bias and quality of evidence will also be evaluated independently and in duplicate. We will investigate the data to ensure its suitability for NMA, including adequacy of the outcome data and transitivity of treatment effects. We plan to estimate the pooled direct, indirect and the mixed effects for all antithrombotic agents using a NMA. ETHICS AND DISSEMINATION: Due to the nature of the study, there are no ethical concerns nor informed consent required. We anticipate that this NMA will be the first to simultaneously assess the relative effects of multiple antithrombotic agents in patients undergoing CABG. The results of this NMA will inform clinicians, patients and guideline developers the best available evidence on comparative effects benefits of antithrombotic agents after CABG while considering the side effect profile to support future clinical decision-making. We will disseminate the results of our systematic review and NMA through a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42017065678

The coastal environment and human health : microbial indicators, pathogens, sentinels and reservoirs

© 2008 Author et al. This is an open access article distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Environmental Health 7 (2008): S3, doi:10.1186/1476-069X-7-S2-S3.Innovative research relating oceans and human health is advancing our understanding of disease-causing organisms in coastal ecosystems. Novel techniques are elucidating the loading, transport and fate of pathogens in coastal ecosystems, and identifying sources of contamination. This research is facilitating improved risk assessments for seafood consumers and those who use the oceans for recreation. A number of challenges still remain and define future directions of research and public policy. Sample processing and molecular detection techniques need to be advanced to allow rapid and specific identification of microbes of public health concern from complex environmental samples. Water quality standards need to be updated to more accurately reflect health risks and to provide managers with improved tools for decision-making. Greater discrimination of virulent versus harmless microbes is needed to identify environmental reservoirs of pathogens and factors leading to human infections. Investigations must include examination of microbial community dynamics that may be important from a human health perspective. Further research is needed to evaluate the ecology of non-enteric water-transmitted diseases. Sentinels should also be established and monitored, providing early warning of dangers to ecosystem health. Taken together, this effort will provide more reliable information about public health risks associated with beaches and seafood consumption, and how human activities can affect their exposure to disease-causing organisms from the oceans.The Oceans and Human Health Initiative research described within this paper is supported by the National Science Foundation, The National Institute for Environmental Health Sciences and the National Oceanic and Atmospheric Administration. Grant numbers are: NIEHS P50 ES012742 and NSF OCE- 043072 (RJG, LAA-Z, MFP), NSF OCE04-32479 and NIEHS P50 ES012740 (RSF), NSF OCE-0432368 and NIEHS P50 ES12736 (HMS-G), NIEHS P50 ES012762 and NSF OCE-0434087 (JSM)

Prominent Human Health Impacts from Several Marine Microbes: History, Ecology, and Public Health Implications

This paper overviews several examples of important public health impacts by marine microbes and directs readers to the extensive literature germane to these maladies. These examples include three types of dinoflagellates (Gambierdiscus spp., Karenia brevis, and Alexandrium fundyense), BMAA-producing cyanobacteria, and infectious microbes. The dinoflagellates are responsible for ciguatera fish poisoning, neurotoxic shellfish poisoning, and paralytic shellfish poisoning, respectively, that have plagued coastal populations over time. Research interest on the potential for marine cyanobacteria to contribute BMAA into human food supplies has been derived by BMAA's discovery in cycad seeds and subsequent implication as the putative cause of amyotrophic lateral sclerosis/parkinsonism dementia complex among the Chamorro people of Guam. Recent UPLC/MS analyses indicate that recent reports that BMAA is prolifically distributed among marine cyanobacteria at high concentrations may be due to analyte misidentification in the analytical protocols being applied for BMAA. Common infectious microbes (including enterovirus, norovirus, Salmonella, Campylobacter, Shigella, Staphylococcus aureus, Cryptosporidium, and Giardia) cause gastrointestinal and skin-related illness. These microbes can be introduced from external human and animal sources, or they can be indigenous to the marine environment

Routine screening of harmful microorganisms in beach sands: implications to public health

Beaches worldwide provide recreational opportunities to hundreds of millions of people and serve as important components of coastal economies. Beach water is often monitored for microbiological quality to detect the presence of indicators of human sewage contamination so as to prevent public health outbreaks associated with water contact. However, growing evidence suggests that beach sand can harbor microbes harmful to human health, often in concentrations greater than the beach water. Currently, there are no standards for monitoring, sampling, analyzing, or managing beach sand quality. In addition to indicator microbes, growing evidence has identified pathogenic bacteria, viruses, and fungi in a variety of beach sands worldwide. The public health threat associated with these populations through direct and indirect contact is unknown because so little research has been conducted relating to health outcomes associated with sand quality. In this manuscript, we present the consensus findings of a workshop of experts convened in Lisbon, Portugal to discuss the current state of knowledge on beach sand microbiological quality and to develop suggestions for standardizing the evaluation of sand at coastal beaches. The expert group at the "Microareias 2012" workshop recommends that 1) beach sand should be screened for a variety of pathogens harmful to human health, and sand monitoring should then be initiated alongside regular water monitoring; 2) sampling and analysis protocols should be standardized to allow proper comparisons among beach locations; and 3) further studies are needed to estimate human health risk with exposure to contaminated beach sand. Much of the manuscript is focused on research specific to Portugal, but similar results have been found elsewhere, and the findings have worldwide implications

Impacts of Hurricanes Katrina and Rita on the microbial landscape of the New Orleans area

Author Posting. © The Author(s), 2007. This is the author's version of the work. It is posted here by permission of National Academy of Sciences of the USA for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences 104 (2007): 9029-9034, doi:10.1073/pnas.0610552104.Floodwaters in New Orleans from Hurricanes Katrina and Rita were observed to contain high levels of fecal indicator bacteria and microbial pathogens, generating concern about long-term impacts of these floodwaters on the sediment and water quality of the New Orleans area and Lake Pontchartrain. We show here that fecal indicator microbe concentrations in offshore waters from Lake Pontchartrain returned to prehurricane concentrations within 2 months of the flooding induced by these hurricanes. Vibrio and Legionella species within the lake were more abundant in samples collected shortly after the floodwaters had receded compared with samples taken within the subsequent 3 months; no evidence of a long-term hurricane-induced algal bloom was observed. Giardia and Cryptosporidium were detected in canal waters. Elevated levels of fecal indicator bacteria observed in sediment could not be solely attributed to impacts from floodwaters, as both flooded and nonflooded areas exhibited elevated levels of fecal indicator bacteria. Evidence from measurements of Bifidobacterium and bacterial diversity analysis suggest that the fecal indicator bacteria observed in the sediment were from human fecal sources. Epidemiologic studies are highly recommended to evaluate the human health effects of the sediments deposited by the floodwaters.This work was funded by NSF-NIEHS Oceans and Human Health Program (NSF OCE0432368, OCE0432479, OCE0430724 and NIEHS P50 ES12736, ES012740, ES012742), the NSF-SGER Program (OCE 0554402, OCE 0554674, OCE 0554850, OCE0600130), the NSF-REU Program, and by the Georgia Sea Grant College Program (NA04OAR170033)

Routine screening of harmful microorganisms in beach sands: implications to public health

Beaches worldwide provide recreational opportunities to hundreds of millions of people and serve as important components of coastal economies. Beach water is often monitored for microbiological quality to detect the presence of indicators of human sewage contamination so as to prevent public health outbreaks associated with water contact. However, growing evidence suggests that beach sand can harbor microbes harmful to human health, often in concentrations greater than the beach water. Currently, there are no standards for monitoring, sampling, analyzing, or managing beach sand quality. In addition to indicator microbes, growing evidence has identified pathogenic bacteria, viruses, and fungi in a variety of beach sands worldwide. The public health threat associated with these populations through direct and indirect contact is unknown because so little research has been conducted relating to health outcomes associated with sand quality. In this manuscript, we present the consensus findings of a workshop of experts convened in Lisbon, Portugal to discuss the current state of knowledge on beach sand microbiological quality and to develop suggestions for standardizing the evaluation of sand at coastal beaches. The expert group at the "Microareias 2012" workshop recommends that 1) beach sand should be screened for a variety of pathogens harmful to human health, and sand monitoring should then be initiated alongside regular water monitoring; 2) sampling and analysis protocols should be standardized to allow proper comparisons among beach locations; and 3) further studies are needed to estimate human health risk with exposure to contaminated beach sand. Much of the manuscript is focused on research specific to Portugal, but similar results have been found elsewhere, and the findings have worldwide implications