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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design And Evaluation Of A Large Scale Aerosol Generator

Hogancamp, Tracy Kristina 10 December 2005 (has links)
The Diagnostic Instrumentation and Analysis Laboratory (DIAL) at Mississippi State University was awarded a project to study the feasibility of measuring particulate matter downstream of a high efficiency particulate air (HEPA) filter by testing commercially available equipment used to monitor the downstream side of a HEPA filter. In order to perform the work required for this project, a test stand to accommodate a 12? x 12? x 11.5? HEPA filter with a rated flow of 250 standard cubic feet per minute (scfm) was constructed. The test stand required an aerosol generator capable of producing a mass loading rate of 30 mg/m3 of dry aerosol at the face of the HEPA filter. It was determined that there was not a commercially available aerosol generator that quite fit the needs of the project. Therefore, it was necessary to develop an aerosol generator with the capabilities required for the project.
2

Design and Set Up of a System for Testing HEPA Filter Efficiency

Smigielski, Ken Alan 25 September 2007 (has links)
No description available.
3

Humidity effects on hygroscopic particles deposited on HEPA filters and silicon wafer surfaces

Ponkala, Mikko Juha Viljami 24 April 2013 (has links)
Semiconductor wafer manufacturing facilities (fab) must maintain extremely clean air environments to minimize the number of wafers scrapped due to contamination which would result in reduced yields. The fab air is cleaned bypassing it through either HEPA or ULPA filters. A number of airborne fab contaminants may be hygroscopic causing them to exist as a solid or a liquid when in equilibrium with their environment's relative humidity. The effect of relative humidity on such contaminants is poorly documented whether they were to be captured in a filter or deposited on a wafer. The work presented here experimentally characterizes NaCl evolution within HEPA filters when exposed to humidity fluctuations and the effect of humidity on NH4Cl corrosiveness when deposited on cobalt coated wafers with a TiN layer. Successive deliquescence and efflorescence fluctuations were imposed on particles captured on a glass fiber HEPA filter. Scanning Electron Microscopy (SEM) and Environmental SEM (ESEM) studies of the filters showed that the NaCl, under humidity excursions, did not penetrate deep into the filter but deliquesced and effloresced near the top surface of the filter. Pressure drop measurements for filters containing NaCl particles showed differences in pressure drop associated with relative humidity changes. These pressure drop changes suggested some redistribution particle properties. When exposed to a relative humidity of 20%, the NH4Cl particles did not corrode the cobalt wafer beyond the location of the initial deposit. At 61% relative humidity, the surrounding areas of the particles were corroded with a solid artifact left at the original location. At 76% relative humidity the NH4Cl particles were observed to have deliquesced, which is below the expected deliquescence relative humidity. The corrosion of the cobalt wafer was most extensive when the NH4Cl particles had deliquesced. / text
4

Evaluation Of A Test Stand To Assess The Performance Of A Range Of Ceramic Media Filter Elements

Schemmel, Andrew L 06 May 2017 (has links)
High Efficiency Particulate Air (HEPA) filters are defined as extended-medium, dry-type filters with: (1) a minimum particle removal efficiency of no less than 99.97 percent for 0.3 micrometer particles, (2) a maximum, clean resistance of 1.0 inch water column (in. WC) when operated at 1,000 cubic feet per minute (CFM), and (3) a rigid casing that extends the full depth of the medium. Specifically, ceramic media HEPA filters provide better performance at elevated temperatures, are moisture resistant and nonflammable, can perform their function if wetted and exposed to greater pressures, and can be cleaned and reused. This paper describes the modification and design of a large scale test stand which properly evaluates the filtration characteristics of a range of ceramic media filters challenged with a nuclear aerosol agent in order to develop Section FO of ASME AG-1.
5

Kan hälsofrämjande fysisk aktivitet användas för att lindra depression : En systematisk litteraturöversikt

Svensson, Dennis, Toulikas, Elias January 2021 (has links)
Introduktion: Psykisk ohälsa är något miljoner människor går igenom, depression är en av de psykiska sjukdomarna som är vanliga. Att ha depression kan resultera i att få sömnsvårigheter, lite energi och motivation, samt ångest. Idag är vanliga behandlingsmetoder mot depression är antidepressiva läkemedel eller olika former av terapi. Olika typer av hälsofrämjande fysisk aktivitet (HEPA) har tidigare visats ge positiva effekter för hälsan men har det någon påverkan på depression? Syfte: Syfte med studien var att genom en systematisk litteraturgenomgång undersöka om depression kan lindras med hjälp av hälsofrämjande fysisk aktivitet (HEPA) med hjälp av tidigare framtagen forskning. Metod: Studier från de senaste årtiondet användes för att få mer information och fakta om (HEPA) påverkan på depression. Resultat: Alla studier visade en positiv korrelation mellan (HEPA) och depression. En anledning för detta kan vara att (HEPA) frigör exempelvis serotonin, endorfiner och dopamin som har visat ge positiv effekt på en individs psykiska hälsa. Andra effekter (HEPA) hade på individerna som deltog i studierna var mindre ångest, bättre humör, och mer energi för att nämna några. Konklusion: Varje studie som användes visade att (HEPA) hade en positiv effekt på individer med depression. Trots att studierna visat detta, så bör fler studier göras för att kunna fastställa att olika former av (HEPA) kan ha en positiv effekt på depression. / Introduction: Mental illness is something that millions of people go through, depression is one of the mental disorders that is usual. Having depression can result in having problems sleeping, little energy and motivation, anxiety. Today common treatments for depression are either antidepressant medicine, or different forms of therapy. Different types of health-enhancing physical activity (HEPA) is something almost any person can perform and is therefore something to take into consideration for someone struggling with depression. Previous studies have shown that (HEPA) can have positive health benefits, but can it have a positive effect on depression? Purpose: The purpose of the study was to examine through a systematic literature review whether depression can be alleviated with the help of health-promoting physical activity (HEPA) with help of previously developed research. Method: Studies from the last decade were used to get facts and more information about (HEPA)and its effect on depression. Result: All the studies that were used showed a positive correlation between (HEPA) on depression. A reason for this is that (HEPA) releases for instance serotonin, endorphins and dopamine that allt have shown to have a positive effect on individuals' psychological health. Other effects that (HEPA) had on the individuals that participated in the studies was less anxiety, better mood, and more energy, to only mention a few. Conclusion: Every study that was used showed that (HEPA) has a positive effect on individuals with depression. Even though these studies have shown this, more studies need to be done in order to determine that different types of (HEPA) have a positive effect on depression.
6

Effectiveness of Ventilating Headboards in Protecting Health-Care Workers in Hospital Rooms

Dungi, Santosh Roopak 13 October 2014 (has links)
No description available.
7

Filtrace vzduchu v systémech vzduchotechniky / The filtration in air conditioning systems

Viktorin, Michal January 2017 (has links)
The diploma thesis is divided into three parts, analysis of the topic and the chosen method of solutions, application to specified building and experimental solutions and data processing The first part is theoretical. It is about air filtration in terms of normative and legal requirements and variants of technical solutions for air filtration. In the second part there are two technical solutions for HVAC systems for plastic surgery. The third part is experimental. It is the measurement of the number of particles in the air in the operating room and the evaluation of the measurement.
8

Návrh větrání laboratoře pro přípravu cytostatik / Ventilation of a cytostatic laboratory

Kicko, Peter January 2013 (has links)
The main goal of this thesis is an introducing and guiding the reader with all important aspects of a proposal of ventilation system for cytostatics laboratory, from theoretical knowledge about the issue via familiarization with an appropriate legislative statute, a demonstration of relevant calculations needed for the project, a proposal in the form of technical reports as well. In this thesis the process of validation, which is needed for installed technology in the cleanroom, is also described. The thesis is supported by drawing documentation of real ventilation project for cytostatics laboratory, which follows the aforementioned technical report and calculations.
9

Teoretické využití nanotechnologie pro filtraci ve vzduchotechnice / Theoretical use of nanotechnology for filtration in HVAC systems

Bosák, Jan January 2016 (has links)
Thesis solves problems using the nanotechnology for air filtration in HVAC systems. Main specialization work is air filtration for clean spaces with high classes of purity. For example Hospitals, sophisticated technology service, pharmacy etc. Thesis is devide for three parts. First part contains foundation infromations about theory and making fabrics by nanotechnology. Next I described laws of physics, That were using during the solving filtration´s issues. Goal for second part was making the experiments, which should show abilities and properties nanofilters during the air filtration in real environment HVAC systems. In the end measure part is compare nanofilters with common filters. There is describe nanofiltres behavior and their possibilies during the filtration as well as. In last part I expressed own opinions on air filtration by nanofibers. Opinions were making throught informations, That I found out in the process working on thesis and my experiences in HVAC field. By this facts I did compare for get a better idea. Additionally last part contains summary infomations from previously parts and own vision to development in the future. Goal work isn´t promotion and advertising sorts technologies. Ask is just summary and describe discovered knowledges, considered opinions ensue from measuring, information from the Net and people Who work in nanotechnology field.
10

Monitoramento de fungos no ar comparação da quantidade de elementos fúngicos viáveis em dois centros de Transplante de Células-Tronco Hematopoéticas (TCTH) em Porto Alegre

Brun, Caroline Pellicioli January 2011 (has links)
Infecções fúngicas invasivas têm emergido como causa de alta morbimortalidade entre pacientes com neoplasia hematológicas, principalmente os submetidos a transplante de células-tronco hematopoéticas (TCTH). Fungos estão onipresentes na natureza, logo, medidas com o objetivo de reduzir a carga fúngica em ambientes hospitalares têm sido preconizadas. No presente estudo, foi realizada coleta de fungos no ar em dois centros de referência em TCTH do sul do Brasil, que possuem instalações distintas, assim como diferentes formas de controle de ar. Todos os quartos do hospital 2 são equipados com filtro de partículas de ar de alta eficiência (HEPA), enquanto no hospital 1 não há sistema específico de filtragem do ar; além disso, os pacientes internados no hospital 2 são de maior risco para doença fúngica invasiva, em função de fatores relacionados ao hospedeiro. Foram realizadas 130 coletas de ar no período de dezembro de 2009 a janeiro de 2011, sendo as amostras provenientes de quartos, banheiros e corredor. Para fins de análise, os fungos pertencentes ao gênero Aspergillus, Rhizopus e Fusarium foram considerados como fungos filamentosos potencialmente patogênicos, enquanto os demais fungos foram classificados como ambientais. A comparação entre os corredores dos hospitais 1 e 2 não mostrou diferença quanto a quantidade de fungos isolados (p=0,114 para fungos ambientais e p=0,622 para fungos filamentosos potencialmente patogênicos). Já os quartos de ambos os hospitais apresentaram redução significativa na quantidade de fungos filamentosos potencialmente patogênicos, quando comparados com os corredores (p<0,0001). Comparando-se os quartos dos hospitais 1 e 2, observou-se menor quantidade de fungos ambientais no hospital 2 (p<0,0001); contudo, para fungos filamentosos potencialmente patogênicos não se encontrou diferença (p=0,7145). Durante o período de estudo, a incidência de doença fúngica invasiva por fungos filamentosos foi de 2,1% no hospital 1 e 7,6% no hospital 2. A baixa carga fúngica nos quartos do hospital 1 poderia ser explicadas pelo uso de medidas protetoras adicionais, incluindo janelas e portas fechadas, reforçando-se a importância de tais medidas no cuidados em ambientes protegidos. / Invasive fungal infections have emerged as a cause of high morbidity and mortality among patients with hematologic malignancies, especially among those undergoing hematopoietic stem cell transplantation. Fungi are ubiquitous in nature, therefore measures aimed at reducing fungal burden in hospitals have been emphasized. In this study air samples were collected in two HSCT centers in Southern Brazil, which have distinct facilities, as well diferent air control systems. All rooms of hospital 2 are equipped with HEPA filters. In addition, patients hospitalized in this unit are at a higher risk for invasive fungal diseases. A total of 130 samples were obtained during December 2009 to January 2011 from rooms, restrooms and corridors. For analysis, all fungi belonging to the genus Aspergillus, Rhizopus and Fusarium were considered filamentous fungi potentially pathogenic, while others were considered environmental fungi. The comparison between corridors of hospital 1 and 2 showed no difference in fungal concentration (p=0.114 for environmental fungi and p=0.622 for potentially pathogenic). The rooms of both hospitals showed a significant lower concentration in PPF, as compared to corridors (p<0.0001). Comparing rooms of hospital 1 e 2 there was a lower amount of environmental fungi in hospital 2 (p<0.0001) – however no difference was observed for potentially pathogenic (p=0.714). During the period of study, the incidence of invasive mold infection was 2.1% in hospital 1 and 7.6% in hospital 2. The low fungal burden in rooms in hospital 1 may be explained by the implementation of additional protective measures, emphasizing the importance of such measures in protected environments.

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