Academic literature on the topic 'Reducing contamination rates'
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Journal articles on the topic "Reducing contamination rates"
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Harding, Andrew D., and Susan Bollinger. "Reducing Blood Culture Contamination Rates in the Emergency Department." Journal of Emergency Nursing 39, no. 1 (January 2013): e1-e6. http://dx.doi.org/10.1016/j.jen.2012.10.009.
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Halstead, Diane C., Robert L. Sautter, James W. Snyder, Arthur E. Crist, and Irving Nachamkin. "Reducing Blood Culture Contamination Rates: Experiences of Four Hospital Systems." Infectious Diseases and Therapy 9, no. 2 (April 30, 2020): 389–401. http://dx.doi.org/10.1007/s40121-020-00299-1.
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Gupta, Itisha, and Jane Codd. "Reducing Blood Culture Contamination; a Quality Improvement Project in Emergency Department." Infection Control & Hospital Epidemiology 41, S1 (October 2020): s368—s369. http://dx.doi.org/10.1017/ice.2020.995.
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Background: Blood culture is an important investigation in diagnosing sepsis. Positive culture helps to tailor therapy and is crucial in antimicrobial stewardship (AMS). However, positive blood culture does not always denote a bloodstream infection. Sometimes, false-positive results occur because of contamination from organisms outside the bloodstream, leading to significant negative consequences to patient treatment decisions and financial implications. Rates of blood culture contamination vary widely (0.6%–6%) between organizations, and although it is very difficult to eliminate contamination, it can be minimized. Our hospital group has multiple sites including emergency departments (EDs). We have been intermittently monitoring blood culture contamination rates since 2008, which decreased from 6.8% to 4.8% in 2009 but remained static when audited in 2010, 2012, and 2015. Objectives: To reduce our blood culture contamination rate further by targeting 2 busy EDs and by introducing continuous surveillance of blood culture contamination across 3 hospitals beginning in April 2016. Methods: In 2015, for the first time, blood culture contamination rates for both EDs, based in 2 different hospitals, were calculated. The ED results were communicated to the healthcare workers (HCWs), who agreed to establish a continuous surveillance of blood culture contamination and to participate in a reduction plan. Competency training was conducted according to training needs analysis. For example, phlebotomists were trained to ensure the use of the appropriate blood culture kit and educational sessions were tailored to staff groups. The blood culture contamination rate was monitored from April 2016 to March 2019 for 3 hospitals and both EDs to determine the impact of various measures introduced during this time. Results: In 2015, contamination rate of the 3 hospitals was 4.07%, and 10.2% of total blood cultures flagged positive. Also, 25% of blood cultures were requested from Eds, but these samples comprised 54% of the total contamination. The contamination rates for EDs A and B were 7.4% and 10.6%, respectively, which were significantly higher than the overall rate. From April 16 to March 19, there was 22% increase in total blood cultures performed. Results were analyzed quarterly. In total, 8,525 blood culture sets were received in January–March 2019; of these, the EDs contributed 2,799 sets (32.8%). The total blood culture contamination rate in January–March 2019 decreased to 3.1%. Both EDs A and B showed decreases in their contamination rates to 5.5% and 7.4%, respectively, in 2018–2019. The quarterly decreases were 5.2% and 4.9% in January–March 2019. Conclusions: The emphasis on the sepsis pathway probably led to year-on-year increases in total blood culture sets. Both ED blood culture contamination rates decreased. Consistent efforts in education, training, ensuring competency to various HCW groups, and provision of adequate blood culture kits are important for sustaining these improvements.Funding: NoneDisclosures: None
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Ramlal, Bharat, Rosemary Renouf, and Jaber Aslanzadeh. "157. Reducing Blood Culture Contamination Rates Through the Use of a Red Top Tube Discard." Open Forum Infectious Diseases 5, suppl_1 (November 2018): S12—S13. http://dx.doi.org/10.1093/ofid/ofy209.027.
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Abstract Background Septicemia is a major cause of death in the United States and accounts for up to $16.7 billion in annual health care expenses. Blood culture is the gold standard for laboratory diagnosis of bacteremia and resultant septicemia; however, false-positive blood cultures hinder the accurate determination of true bacteremia with often serious implications. The goal of this study was to determine the efficacy of collecting a 1 mL discard in a red tube prior to blood culture collection and to assess its effectiveness in reducing contamination rates in Hartford Hospital Emergency Department (HHED). Methods During the months of June to December 2017 blood cultures were collected by the phlebotomy team using ChloraPrep (chlorhexidine) as the sole disinfecting agent. Blood cultures consisted of BD BACTEC plus Aerobic/F and BD BACTEC Lytic/10 Anaerobic drawn at the same time and monitored on BD BACTEC FX instrument for 5 days. Prior to collecting blood cultures 1 mL of blood was collected in a red top tube and discarded. Monthly and overall contamination rates were then compared with 2016 in which a red top discard tube was not used. Results During June to December 2016, there were a total of 9,576 blood cultures collected with a total of 178 contaminants and an overall contamination rate of 1.9%. During June to December 2017, there were a total of 9,133 blood cultures collected with a total of 73 contaminants and an overall contamination rate of 0.8%. During both years, our contamination rates were well below the CLSI recommendation; however, a significant reduction in blood culture contamination was observed after the use of a Red Top discard tube (0.8% vs. 1.9%) (Figures 1–3). Conclusion The cost of a standard blood draw with Red Top tubes is minimal (few cents) while a single collection using an initial specimen diversion device (ISDD) can range from $15 to $18. During the course of this study, the use of a standard Red Top discard cost approximately $456 (2017); if an ISDD was used instead, this would have generated $136,995 in healthcare cost. At our institution, we were able to keep our contamination rates below 1% after the implementation of a standard Red Top discard tube. This suggests that the use of a Red Top discard prior to blood culture collection is an effective means for reducing and maintaining a low blood contamination rate. Disclosures All authors: No reported disclosures.
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Bentley, James, Shobhan Thakore, L. Muir, Alastair Baird, and Jennifer Lee. "A change of culture: reducing blood culture contamination rates in an Emergency Department." BMJ Quality Improvement Reports 5, no. 1 (2016): u206760.w2754. http://dx.doi.org/10.1136/bmjquality.u206760.w2754.
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Hopkins, Kathie, Sheila Huynh, Catherine McNary, Ashley Walker, Richard Nixon, and Janet E. Craighead. "Reducing blood culture contamination rates: A systematic approach to improving quality of care." American Journal of Infection Control 41, no. 12 (December 2013): 1272–74. http://dx.doi.org/10.1016/j.ajic.2013.02.019.
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Bell, Mary, Catherine Bogar, Jessica Plante, Kristen Rasmussen, and Sharon Winters. "Effectiveness of a Novel Specimen Collection System in Reducing Blood Culture Contamination Rates." Journal of Emergency Nursing 44, no. 6 (November 2018): 570–75. http://dx.doi.org/10.1016/j.jen.2018.03.007.
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Bhanot, Nitin, Sriharsha Rao, Shobha Sharma, Edmond S. Malka, Monica Ghitan, Purba Gupta, Andrew G. Sahud, Betsy McCaughey, and Edward K. Chapnick. "Effectiveness and feasibility of using a physical barrier device in reducing rates of microbial contamination of sphygmomanometer cuffs." Journal of Infection Prevention 12, no. 6 (September 29, 2011): 241–45. http://dx.doi.org/10.1177/1757177411415446.
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phygmomanometers are frequently contaminated with bacteria and are implicated in the transmission of microbes. A pilot study was conducted to determine the effectiveness and feasibility of using a physical barrier device in reducing rates of microbial contamination of sphygmomanometer cuffs. Blood pressure recordings were made with and without a disposable plastic device on healthy individuals to ensure that it did not interfere with the accuracy of readings. Baseline rates of microbial colonisation of sphygmomanometer cuffs were obtained over a six week period. For six weeks the device was applied to patients’ arms before measuring blood pressure, and sphygmomanometer cuffs were recultured during the intervention period. No difference was found in blood pressure recordings with and without the device. No difference in rates of bacterial contamination was observed during the intervention phase of the study. A disposable plastic device acting as a physical barrier may not reduce surface contamination of sphygmomanometer cuffs.
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Kaplan, Chaim, Redentor Mendiola, Victorine Ndjatou, Edward Chapnick, and Howard Minkoff. "The role of covering gowns in reducing rates of bacterial contamination of scrub suits." American Journal of Obstetrics and Gynecology 188, no. 5 (May 2003): 1154–55. http://dx.doi.org/10.1067/mob.2003.296.
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Kaplan, Chaim, Redentor Mendiola, Victorine Ndjatou, Edward Chapnick, and Howard Minkoff. "The Role of Covering Gowns in Reducing Rates of Bacterial Contamination of Scrub Suits." Obstetrical & Gynecological Survey 58, no. 9 (September 2003): 582–83. http://dx.doi.org/10.1097/01.ogx.0000083712.63851.17.
Full textBook chapters on the topic "Reducing contamination rates"
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S. Amaral, Mateus, Carla C.A. Loures, Fabiano L. Naves, Gisella L. Samanamud, Messias B. Silva, and Arnaldo M.R. Prata. "Microalgae Cultivation in Photobioreactors Aiming at Biodiesel Production." In Biomass [Working Title]. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.93547.
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The search for a renewable source as an alternative to fossil fuels has driven the research on new sources of biomass for biofuels. An alternative source of biomass that has come to prominence is microalgae, photosynthetic micro-organisms capable of capturing atmospheric CO2 and accumulating high levels of lipids in their biomass, making them attractive as a raw material for biodiesel synthesis. Thus, various studies have been conducted in developing different types of photobioreactors for the cultivation of microalgae. Photobioreactors can be divided into two groups: open and closed. Open photobioreactors are more susceptible to contamination and bad weather, reducing biomass productivity. Closed photobioreactors allow greater control against contamination and bad weather and lead to higher rates of biomass production; they are widely used in research to improve new species and processes. Therefore, many configurations of closed photobioreactors have been developed over the years to increase productivity of microalgae biomass.
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Sohail, Sidra, Muhammad Fraz Ali, Usman Zulfiqar, Saddam Hussain, and Shaharyar Khosa. "Influence of Sewage Sludge and Heavy Fertilization on Nitrate Leaching in Soils: An Overview." In Environmental Sciences. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.107056.
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Sewage sludge is now widely used for production of crops throughout the world. Utilizing the sewage sludge for crop production has various advantages such as nutrient recycling, reducing the need for mineral fertilizer, increasing organic matter amount in soils, and improving physical properties of soil. A large amount of sludge is generated during the sewage treatment process, and it is disposed off on land in the form of fertilizer or soil conditioner. In this, heavy metals are usually in greater concentration than in soil, which is one of the main problems which restricts its utilization as a fertilizer. Nitrate leaching and heavy fertilization cause serious problems for the groundwater and this issue of nitrate leaching is usually neglected. Continuous used of swage sludge cause contamination of soil and water and affects plant growth and soil microorganisms. In this chapter, we have focused on i) various factors which affects nitrate leaching in soil, it includes soil texture, rate of fertilization, season and climate, ii) strategies to reduce nitrate leaching and iii) nitrogen conversion mechanism in sewage sludge.
Conference papers on the topic "Reducing contamination rates"
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Dawson, Gaynor, and Tom McKeon. "Green Remediation: Enhanced Reductive Dechlorination Using Recycled Rinsewater as Bioremediation Substrate." In The 11th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2007. http://dx.doi.org/10.1115/icem2007-7090.
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Enhanced reductive dechlorination (ERD) has rapidly become a remedy of choice for use on chlorinated solvent contamination when site conditions allow. With this approach, solutions of an organic substrate are injected into the affected aquifer to stimulate biological growth and the resultant production of reducing conditions in the target zone. Under the reducing conditions, hydrogen is produced and ultimately replaces chlorine atoms on the contaminant molecule causing sequential dechlorination. Under suitable conditions the process continues until the parent hydrocarbon precursor is produced, such as the complete dechlorination of trichloroethylene (TCE) to ethene. The process is optimized by use of a substrate that maximizes hydrogen production per unit cost. When natural biota are not present to promote the desired degradation, inoculates can be added with the substrate. The in-situ method both reduces cost and accelerates cleanup. Successful applications have been extended from the most common chlorinated compounds perchloroethylene (PCE) and TCE and related products of degradation, to perchlorate, and even explosives such as RDX and trinitrotoluene on which nitrates are attacked in lieu of chloride. In recent work, the process has been further improved through use of beverage industry wastewaters that are available at little or no cost. With material cost removed from the equation, applications can maximize the substrate loading without significantly increasing total cost. The extra substrate loading both accelerates reaction rates and extends the period of time over which reducing conditions are maintained. In some cases, the presence of other organic matter in addition to simple sugars provides for longer performance times of individual injections, thereby working in a fashion similar to emulsified vegetable oil. The paper discusses results of applications at three different sites contaminated with chlorinated ethylenes. The applications have included wastewaters of both natural fruit juices and corn syrup solutions from carbonated beverages. Cost implications include both the reduced cost of substrate and the cost avoidance of needing to pay for treatment of the wastewater.
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Jenkins, Alyn, Santosh Gopi, Jody Hoshowski, Warinthon Lertpornsuksawat, Jennifer Jackson, and Thomas Wilson. "Application of a New H2S Scavenger with Improved Performance in The Field." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206057-ms.
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The presence of hydrogen sulfide (H2S) gas occurs naturally, or can be introduced via bacteria contamination, in oil and gas reservoirs worldwide. There are several options for the removal of H2S from produced oil and gas ranging from fixed assets that scrub H2S to chemical injection at the wellsite. The area of interest for many operators is in the continuous application of non-reversible chemical H2S scavengers as an easy, reliable and cost-effective solution. The majority of the non-reversible chemical H2S scavenger market is based on triazine technology derived from the reaction products of formaldehyde and amines. In recent past, there has been an active industry wide search to improve the overall performance of H2S scavengers. Major topics for improvement include: Increased H2S scavenging capacityReduction of nitrogen contamination of crude oilReduction of scale formationElimination of by-product depositionAddressing existing environmental, health and safety concernsMinimization of products/reaction by-products disposal Conversely, some of the biggest hurdles with new H2S scavengers are ensuring fast kinetic reaction rates, system compatibility, consumption rates, minimal precipitation of scavenger/by-products, scalable manufacturing and competitive economics. Many new products have been proposed by chemical manufactures but often are not able to deliver enough benefits to warrant a change from the industry standard triazine. One potential solution is to pull through a technology from a different industry that already has established production, in significant volumes, for use in oilfield applications. Ideally, the new product would offer better performance versus the incumbent, a reduction in nitrogen content and minimize solids formation and deposition. A product identified several years ago as a potential replacement was an oxazolidine derivative referred to as MBO (3,3’-methylenebis(5-methyloxazolidine)). However, MBO has had limited application in the field until recently. MBO offers some of the same benefits as triazine but outperforms the incumbent technology by increasing the consumption of H2S per mole of scavenger, reducing the nitrogen content in crude oil, reducing the by-product deposition potential. Moreover, MBO is already produced in large manufacturing quantities. In this paper we will discuss details about the chemistry and increased formaldehyde content, laboratory results related to performance, system compatibilities, decreased transportation cost and confirmation of field application on large scale that supports the usage of this alternative H2S scavenger to standard triazine. H2S scavengers are used to mitigate the risks presented by H2S. They react with H2S in the liquid phase to form non-hazardous, non-reactive species that are often water soluble and thus disposed with water. Monoethanolamine (MEA) triazine (hexahydro-1,3,5-tris(hydroxyethyl)-s-triazine) is the most widely used scavenger. It is less toxic than most aldehyde scavengers and reacts very quickly with H2S. MEA triazine reacts irreversibly with H2S to form dithiazine (5-hydroxyethylhexahydrodithiazine). One of the major concerns with MEA triazine is that there is a strong possibility of the by-product MEA reacting with excess H2S to form an ethanolammonium sulfide species that in turn reacts with the dithiazine to form a largely insoluble polymer, commonly referred to as amorphous dithiazine. An alternative triazine used in oil and gas production is monomethylamine (MMA) triazine (1,3,5-trimethyl hexahydro-s-triazine). MMA triazine has greater volatility than MEA triazine so is more suitable for dry gas applications. In the cases on MEA triazine and MMA triazine the ratio to amine:formaldehyde is 1:1.
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Smith, Barton L., Zachary E. Humes, and Angela Minichiello. "Particle Size Classification Through Aerodynamic Jet Vectoring." In ASME/JSME 2007 5th Joint Fluids Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/fedsm2007-37267.
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An experimental and numerical demonstration of a new, non-contact particle sorting technique called Aerodynamic Vectoring Particle Sorting (AVPS) is presented. AVPS uses secondary blowing and suction control flows to sharply turn a 2D, particle-laden jet. As the jet is turned, particles present in the flow experience a resultant force, dependent upon their size and due to the combined effects of pressure, inertia, and drag. Since the balance of these forces determines the particle’s trajectory, turning the flow leads to a separation of particles downstream. This simple, low-pressure-drop sorting technique classifies particles with less risk of damage or contamination than currently available sorting devices. AVPS is experimentally demonstrated using a rectangular air jet. Particle size are measured using the Shadowgraphy method. Numerical simulations are performed using the commercial CFD solver FLUENT to calculate the 2D turbulent vectored jet flow field using a RANS approach. Examination of the mean and the standard deviation of measured and computed particle trajectories is used to determine the range of particle sizes that can be effectively sorted using AVPS. Our results indicate that while vectoring can be achieved with smaller control flow rates when blowing and suction are used together, fluctuations in the velocity field are much smaller when suction only is used. Furthermore, we have demonstrated that the jet flow can be vectored 90 with pure suction and 180 using a new geometry that allows for modification of the blowing angle on the fly. Using pure suction, particles from 10–40 micron and 2.5 times the density of water have been sorted to an accuracy of 1.5 micrometers. Sorting of heavy particles such as these is accomplished at very low speeds, reducing the tendency of damage to the particles. Lighter particles are sorted at higher speeds. Also using pure suction, particles from 5–40 μm and 0.6 times the density of water were sorted to an accuracy of 6.6 μm.
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Younan, Hua, Chu Susan, Gui Dong, Mo Zhiqiang, Xing Zhenxiang, Liu Binghai, Ng Adrian, and Tsai Tony. "A New Failure Analysis Flow of Gate Oxide Integrity Failure in Wafer Fabrication." In ISTFA 2009. ASM International, 2009. http://dx.doi.org/10.31399/asm.cp.istfa2009p0177.
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Abstract As device feature size continues to shrink, the reducing gate oxide thickness puts more stringent requirements on gate dielectric quality in terms of defect density and contamination concentration. As a result, analyzing gate oxide integrity and dielectric breakdown failures during wafer fabrication becomes more difficult. Using a traditional FA flow and methods some defects were observed after electrical fault isolation using emission microscopic tools such as EMMI and TIVA. Even with some success with conventional FA the root cause was unclear. In this paper, we will propose an analysis flow for GOI failures to improve FA’s success rate. In this new proposed flow both a chemical method, Wright Etch, and SIMS analysis techniques are employed to identify root cause of the GOI failures after EFA fault isolation. In general, the shape of the defect might provide information as to the root cause of the GOI failure, whether related to PID or contamination. However, Wright Etch results are inadequate to answer the questions of whether the failure is caused by contamination or not. If there is a contaminate another technique is required to determine what the contaminant is and where it comes from. If the failure is confirmed to be due to contamination, SIMS is used to further determine the contamination source at the ppm-ppb level. In this paper, a real case of GOI failure will be discussed and presented. Using the new failure analysis flow, the root cause was identified to be iron contamination introduced from a worn out part made of stainless steel.
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Si, Xiuhua, Sungmin Youn, and Jinxiang Xi. "Reducing Scale Deposition by Surface Modification and Magnetic Water Treatment." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-12796.
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Scale deposition (or fouling) on metal surfaces from salt-containing water considerably reduces the efficiency and performance of heat transfer equipments. In industrial practices, scale deposition could be reduced through physical or chemical methods. However, in some cases chemical methods are unpractical due to cost and contamination issues, rendering the physical methods the only feasible options. The objective of this study was to evaluate the effectiveness of two physical treatments in reducing scale depositions. One is to decrease the surface energy of the heat exchanger wall through surface modification; the other one is to change the crystallography of the small solid particles formed in the solution by applying a magnetic field. For the first method, the scale deposition on PTFE surfaces, SAMs (self-assembly monolayers) surfaces, polished copper surfaces, and polished stainless steel surfaces are investigated respectively. Copper and stainless steel surfaces were modified by micro-scale (μm thickness) PTFE (Poly-Tetrofluorethylene) films and nano-scale (nm thickness) thiolate SAMs. The surface energy of PTFE films and SAMs layers based on copper and stainless steel were significantly reduced compared with the untreated metal surfaces. To study the magnetic treatment effect on the formation of the calcium carbonate scale, a magnetic field up to 0.6 T was implemented in a simulated recirculation cooling water system. A large number of experiments were performed to study the effects of fluid velocity, heat flux, and the bulk concentration of the solution on the fouling rate and induction period of calcium carbonate on various modified surfaces. The experiments showed that the formation rate of the calcium carbonate scale was decreased on modified surfaces and the induction period was prolonged with the decrease of the surface energy. The study also showed that the nucleation and nucleate growth of calcium carbonate particles were enhanced through magnetic water treatment. In addition, using a higher flow rate and/or filtration of suspended calcium carbonate particles achieves a longer induction period.
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Habchi, Carine Hanna, Kamel Ghali, and Nesreen Ghaddar. "Transient Model for Particle Dispersion Generated by High Momentum Respiratory Activities in Spaces Ventilated by Displacement Ventilation System." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-50255.
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A transient zonal model wit is developed to study particle distribution resulting from transient respiratory activities in spaces ventilated by displacement ventilation system (DV). Two transient sub-models are coupled: a transport model of exhaled particles computing the percentage of generated particles penetrating the infected thermal plume and tracking the exhaled jet propagation, and a transport model predicting particle exchange between the different affected layers and regions. A parametric study was performed to determine the effect of different factors on the risk of cross-infection between the occupants: exhalation velocity, DV flow rate, distance separating the occupants and particle diameter. It was observed that with the increase of the DV flow rate, the ventilation effectiveness increases reducing particle accumulation in the breathing zone. The risk of cross-contamination becomes higher for reduced separating distance between the occupants, and for increased cough velocity, as the momentum of released droplets and their quantity increase. Therefore, it was found that to reduce cross-infection, measures can be considered as avoiding getting close to an infected occupant and covering the mouth during a cough. In addition, assisting DV system by chair fans is expected to reduce cross-contamination by increasing the strength of the rising thermal plumes.
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Wang, Jinjiang, Robert X. Gao, Xinyao Tang, Zhaoyan Fan, and Peng Wang. "Dual-Tree Wavelet Packet Transform for Ultrasonic Data Transmission Through Metal Structures." In ASME 2015 International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/msec2015-9463.
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Data communication through metallic structures is generally encountered in manufacturing equipment and process monitoring and control. This paper presents a signal processing technique for enhancing the signal-to-noise ratio and high-bit data transmission rate in ultrasound-based wireless data transmission through metallic structures. A multi-carrier coded-ultrasonic wave modulation scheme is firstly investigated to achieve high-bit data rate communication while reducing inter-symbol inference and data loss, due to the inherent signal attenuation, wave diffraction and reflection in metallic structures. To improve the signal-to-noise ratio, dual-tree wavelet packet transform (DT-WPT) has been investigated to separate multi-carrier signals under noise contamination, given its properties of shift-invariance and flexible time frequency partitioning. A new envelope extraction and threshold setting strategy for selected wavelet coefficients is then introduced to retrieve the coded digital information. Experimental studies are performed to evaluate the effectiveness of the developed signal processing method for manufacturing.
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Margulies, T. "Nuclear Power Hazard and Economic Risk Assessment." In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-0028.
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Abstract This paper addresses a complex debate of national importance related to the safety of existing light water reactors and preventing, mitigating, or improving emergency preparedness for response to severe reactor accident releases of radioactivity for operating reactors. The costs and benefits of several key alternatives are assessed for the NUREG-1150 reference plants, as well as, a representative medium population density site. Annual levelized cost calculations using a 105 annual release rate were made using ICRP annuity factors for potential safety improvements resulting in cost-beneficial justifications for engineering safety improvements such as supplemental filtering and scrubbing to the present containments, and for instrumentation and monitoring to minimize a bypass scenario. Probabilistic risk financing formulas for expected continuous discounting are presented. Improvements to emergency preparedness measures such as stockpiling potassium iodide for the population would not have the additional protection benefits of reducing substantially non-inhalation pathway contributions to offsite health effects, as well as, protecting land from contamination.
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Ugolini, Daniele, Francesco Rossi, and Francesco Basile. "Decommissioning of the Radio Chemical Hot Laboratory of the European Commission Joint Research Centre of Ispra." In ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2011. http://dx.doi.org/10.1115/icem2011-59207.
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The construction of the Radio Chemical Hot Laboratory (RCHL) of the Joint Research Centre (JRC) of Ispra began in the early 1960s while the laboratory activities started in 1964. In 1976 an annex to the main building was built. At this time the RCHL main research activities were in environment and biochemistry by means of radioactive tracers; neutron activation analyses; extraction of actinides from radioactive liquid waste coming from the nuclear fuel reprocessing plants; and analyses of U, Pu, and Th in samples from the nuclear fuel cycle in order to determine the isotopic ratio and the burn-up. In 1978, a new area of laboratories named “Stabularium” was built to study the metabolism of heavy metal on laboratory animals. Complementary to the laboratory three pneumatic transfer systems for irradiated sources connected the RCHL to two research reactors. The decommissioning activities of the 2650 m2 facility started in January 2008 and they were completed at the end of 2010 with the release for unrestricted use of all the buildings of the facility. They consisted in five main tasks; pre-decommissioning, licensing, dismantling, waste management, and final survey. The main pre-decommissioning activities were the physical and radiological characterization of the facility. The principal licensing activity was the preparation of the delicensing documentation to obtain the license termination from the safety authorities. Dismantling consisted in the removal of all the equipments and ancillary systems, of the pneumatic transfer system, and in the decontamination of the structures of the controlled zone. The waste management was limited to the transfer of the waste and of the clearable material to the centralized waste management facility. The final survey consisted in the final radiological characterization to quantify the concentration of any residual radioactivity remained after the completion of the dismantling activities for the release of the RCHL without any radiological constraints. The safety and radioprotection prescriptions adopted were the minimization of the conventional and nuclear risk for the workers (reducing the dose rate), the minimization of the environmental risks (reducing the external liquid, solid and gaseous releases), and the confinement of the contamination where it was generated. This paper describes the pre-decommissioning, dismantling, and final survey activities undertaken to perform the decommissioning of the RCHL.
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Koch Ferreira, Flávia, João Fiorotti, Leonardo Brunherotto, Marcelo Cunha, Jose Luis Paredes, Thiago Piedade, Rafael Peralta, and Geraldo Filho. "Tailored Dependable Barrier Enables Operator to Flawlessly Complete True One Trip Ultra Slender Deepwater Well." In International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-21977-ms.
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Abstract Drilling time and resources for casing and cementing the wellbore represent a significant cost in oil well construction. Therefore, slender wells have been targeted to be constructed with less phases and higher efficiency reducing costs by half. The objective of this paper is to present how a fit-for-purpose foam cement system contributed to delivering a dependable barrier for a True-One-Trip Ultra-Slender well, where a single barrier shall provide wellbore mechanical integrity and competent isolation from the reservoir to seabed. The methodology for this foam cement job involved, initially, hydraulic and thermal modeling, followed by lab testing, such as thickening time, compressive strength, and foam stability tests. The pumping schedule included 4 different tailored systems that were pumped to maximize probability of returns at the mudline. By using the constant-nitrogen-rate technique, the foam quality was optimized to help ensure slurry and foam stability at downhole conditions. Proper energized fluid selection and casing centralization were placed to guarantee a slurry system application with improved mud removal capacity and optimized standoff to avoid slurry contamination attributed to channeling. During execution, no issues were observed until reaching the final depth. The open hole diameter was estimated based on volumetric determination by pumping a tracer and a scavenger slurry, to be visualized at the mudline. Based on that information, further volumes were fine tuned and pumped to ensure appropriated foam cement quality and density along the wellbore section. As one of the major objectives of the job, returns could be achieved at mudline and the final differential pressure was higher than expected, indicating a cement sheath in the annulus had extensive length. Cement job evaluation was performed after the job using sonic and ultrasonic tools to confirm the quality of the barrier placed in the annulus. Additionally, an advanced Cement Evaluation was executed and showed excellent isolation for the slurries placed in the well. The results from this unprecedented operation in Brazil have proven the features and benefits of using foamed cement in ultra-slender wells for specific challenges, such as: requirement of returns at mudline, application in long length zonal isolation operations, and the necessity of high-strength low-density solutions near the mudline. After this job, similar wells have been constructed in the same area, and the applied technique has continuously proven to be a dependable and sound solution for similar scenarios. Based on the successful case history presented in this paper, the application of foam cement technology in ultra-slender wells represent an innovative and dependable solution for the actual and future high-efficiency wellbore geometries. By reducing the risks of having a single cement sheath in the entire well, it enables the oilwell industry to reduce time and risks during wellbore construction and helps enhance its productivity.
Reports on the topic "Reducing contamination rates"
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Bryant, C. A., S. A. Wilks, and C. W. Keevil. Survival of SARS-CoV-2 on the surfaces of food and food packaging materials. Food Standards Agency, November 2022. http://dx.doi.org/10.46756/sci.fsa.kww583.
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COVID-19, caused by the SARS-CoV-2 virus, was first reported in China in December 2019. The virus has spread rapidly around the world and is currently responsible for 500 million reported cases and over 6.4 million deaths. A risk assessment published by the Foods Standards Agency (FSA) in 2020 (Opens in a new window) concluded that it was very unlikely that you could catch coronavirus via food. This assessment included the worst-case assumption that, if food became contaminated during production, no significant inactivation of virus would occur before consumption. However, the rate of inactivation of virus on products sold at various temperatures was identified as a key uncertainty, because if inactivation does occur more rapidly in some situations, then a lower risk may be more appropriate. This project was commissioned to measure the rate of inactivation of virus on the surface of various types of food and food packaging, reducing that uncertainty. The results will be used to consider whether the assumption currently made in the risk assessment remains appropriate for food kept at a range of temperatures, or whether a lower risk is more appropriate for some. We conducted a laboratory-based study, artificially contaminating infectious SARS-CoV-2 virus onto the surfaces of foods and food packaging. We measured how the amount of infectious virus present on those surfaces declined over time, at a range of temperatures and relative humidity levels, reflecting typical storage conditions. We tested broccoli, peppers, apple, raspberry, cheddar cheese, sliced ham, olives, brine from the olives, white and brown bread crusts, croissants and pain au chocolat. The foods tested were selected as they are commonly sold loose on supermarket shelves or uncovered at deli counters or market stalls, they may be difficult to wash, and they are often consumed without any further processing i.e. cooking. The food packaging materials tested were polyethylene terephthalate (PET1) trays and bottles; aluminium cans and composite drinks cartons. These were selected as they are the most commonly used food packaging materials or consumption of the product may involve direct mouth contact with the packaging. Results showed that virus survival varied depending on the foods and food packaging examined. In several cases, infectious virus was detected for several hours and in some cases for several days, under some conditions tested. For a highly infectious agent such as SARS-CoV-2, which is thought to be transmissible by touching contaminated surfaces and then the face, this confirmation is significant. For most foods tested there was a significant drop in levels of virus contamination over the first 24 hours. However, for cheddar cheese and sliced ham, stored in refrigerated conditions and a range of relative humidity, the virus levels remained high up to a week later, when the testing period was stopped. Both cheddar cheese and sliced ham have high moisture, protein and saturated fat content, possibly offering protection to the virus. When apples and olives were tested, the virus was inactivated to the limit of detection very quickly, within an hour, when the first time point was measured. We suggest that chemicals, such as flavonoids, present in the skin of apples and olives inactivate the virus. The rate of viral decrease was rapid, within a few hours, for croissants and pain au chocolat. These pastries are both coated with a liquid egg wash, which may have an inhibitory effect on the virus. Food packaging materials tested had variable virus survival. For all food packaging, there was a significant drop in levels of virus contamination over the first 24 hours, in all relative humidity conditions and at both 6°C and 21°C; these included PET1 bottles and trays, aluminium cans and composite drinks cartons.
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Malkinson, Mertyn, Irit Davidson, Moshe Kotler, and Richard L. Witter. Epidemiology of Avian Leukosis Virus-subtype J Infection in Broiler Breeder Flocks of Poultry and its Eradication from Pedigree Breeding Stock. United States Department of Agriculture, March 2003. http://dx.doi.org/10.32747/2003.7586459.bard.
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Objectives 1. Establish diagnostic procedures to identify tolerant carrier birds based on a) Isolation of ALV-J from blood, b) Detection of group-specific antigen in cloacal swabs and egg albumen. Application of these procedures to broiler breeder flocks with the purpose of removing virus positive birds from the breeding program. 2. Survey the AL V-J infection status of foundation lines to estimate the feasibility of the eradication program 3. Investigate virus transmission through the embryonated egg (vertical) and between chicks in the early post-hatch period (horizontal). Establish a model for limiting horizontal spread by analyzing parameters operative in the hatchery and brooder house. 4. Compare the pathogenicity of AL V-J isolates for broiler chickens. 5. Determine whether AL V-J poses a human health hazard by examining its replication in mammalian and human cells. Revisions. The: eradication objective had to be terminated in the second year following the closing down of the Poultry Breeders Union (PBU) in Israel. This meant that their foundation flocks ceased to be available for selection. Instead, the following topics were investigated: a) Comparison of commercial breeding flocks with and without myeloid leukosis (matched controls) for viremia and serum antibody levels. b) Pathogenicity of Israeli isolates for turkey poults. c) Improvement of a diagnostic ELISA kit for measuring ALV-J antibodies Background. ALV-J, a novel subgroup of the avian leukosis virus family, was first isolated in 1988 from broiler breeders presenting myeloid leukosis (ML). The extent of its spread among commercial breeding flocks was not appreciated until the disease appeared in the USA in 1994 when it affected several major breeding companies almost simultaneously. In Israel, ML was diagnosed in 1996 and was traced to grandparent flocks imported in 1994-5, and by 1997-8, ML was present in one third of the commercial breeding flocks It was then realized that ALV-J transmission was following a similar pattern to that of other exogenous ALVs but because of its unusual genetic composition, the virus was able to establish an extended tolerant state in infected birds. Although losses from ML in affected flocks were somewhat higher than normal, both immunosuppression and depressed growth rates were encountered in affected broiler flocks and affected their profitability. Conclusions. As a result of the contraction in the number of international primary broiler breeders and exchange of male and female lines among them, ALV-J contamination of broiler breeder flocks affected the broiler industry worldwide within a short time span. The Israeli national breeding company (PBU) played out this scenario and presented us with an opportunity to apply existing information to contain the virus. This BARD project, based on the Israeli experience and with the aid of the ADOL collaborative effort, has managed to offer solutions for identifying and eliminating infected birds based on exhaustive virological and serological tests. The analysis of factors that determine the efficiency of horizontal transmission of virus in the hatchery resulted in the workable solution of raising young chicks in small groups through the brooder period. These results were made available to primary breeders as a strategy for reducing viral transmission. Based on phylogenetic analysis of selected Israeli ALV-J isolates, these could be divided into two groups that reflected the countries of origin of the grandparent stock. Implications. The availability of a simple and reliable means of screening day old chicks for vertical transmission is highly desirable in countries that rely on imported breeding stock for their broiler industry. The possibility that AL V-J may be transmitted to human consumers of broiler meat was discounted experimentally.
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Needham, Glenn R., Uri Gerson, Gloria DeGrandi-Hoffman, D. Samatero, J. Yoder, and William Bruce. Integrated Management of Tracheal Mite, Acarapis woodi, and of Varroa Mite, Varroa jacobsoni, Major Pests of Honey Bees. United States Department of Agriculture, March 2000. http://dx.doi.org/10.32747/2000.7573068.bard.
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Objectives: The Israeli work plan regarding HBTM included: (a) producing a better diagnostic method; (b) following infestations during the season and evaluating damage to resistant bees and, (c) controlling HBTM by conventional means under local conditions. For varroa our plans to try novel control (e.g. oil novel control (e.g. oil patties & essential oils) were initially delayed by very low pest populations, then disrupted by the emergence of fluvalinate resistance. We monitored the spread of resistance to understand it better, and analyzed an underlying biochemical resistance mechanism in varroa. The US work plan focused on novel management methods for both mites with an emphasis on reducing use of traditional insecticides due to resistance and contamination issues. Objectives were: (a) evaluating plant essential oils for varroa control; (b) exploring the vulnerability of varroa to desiccation for their management; and (c) looking for biological variation in HBTM that could explain virulence variability between colonies. Although the initial PI at the USDA Beltsville Bee Lab, W.A. Bruce, retired during the project we made significant strides especially on varroa water balance. Subcontracts were performed by Yoder (Illinois College) on varroa water balance and DeGrandi-Hoffman (USDA) who evaluated plant essential oils for their potential to control varroa. We devised an IPM strategy for mite control i the U.S. Background: Mites that parasitize honey bees are a global problem. They are threatening the survival of managed and feral bees, the well-being of commercial/hobby beekeeping, and due to pollination, the future of some agricultural commodities is threatened. Specific economic consequences of these mites are that: (a) apiculture/breeder business are failing; (b) fewer colonies exist; (c) demand and cost for hive leasing are growing; (d) incidences of bee pathogens are increasing; and, (e) there are ore problems with commercial-reared bees. As a reflection of the continued significance f bee mites, a mite book is now in press (Webster & delaplane, 2000); and the 2nd International Conference on Africanized Honey Bees and Bee Mites is scheduled (April, 2000, Arizona). The first such conference was at OSU (1987, GRN was co-organizer). The major challenge is controlling two very different mites within a colony while not adversely impacting the hive. Colony management practices vary, as do the laws dictating acaricide use. Our basic postulates were that: (a) both mites are of economic importance with moderate to high infestations but not at low rates and, (b) once established they will not be eradicated. A novel strategy was devised that deals with the pests concomitantly by maintaining populations at low levels, without unnecessary recourse to synthetic acaricides. Major Conclusions, Solutions, Achievements: A major recent revelation is that there are several species of "Varroa jacobsoni" (Anderson & Trueman 1999). Work on control, resistance, population dynamics, and virulence awaits knowing whether this is a problem. In the U.S. there was no difference between varroa from three locales in terms of water balance parameters (AZ, MN & PA), which bodes well for our work to date. Winter varroa (U.S.) were more prone to desiccation than during other seasons. Varroa sensitivity to desiccation has important implications for improving IPM. Several botanicals showed some promise for varroa control (thymol & origanum). Unfortunately there is varroa resistance to Apistan in Israel but a resistance mechanism was detected for the first time. The Israel team also has a new method for HBTM diagnosis. Annual tracheal mite population trends in Israel were characterized, which will help in targeting treatment. Effects of HBTM on honey yields were shown. HBTM control by Amitraz was demonstrated for at least 6 months. Showing partial resistance by Buckfast bees to HBTM will be an important IPM tactic in Israel and U.S.