The design and performance evaluation of in-duct, isokinetic samplers capable of testing flat sheet, nuclear-grade High Efficiency Particulate Air (HEPA) filters simultaneously with a radial filter testing system is discussed in this study. Evaluations within this study utilize challenge aerosols of varying particle diameters and masses such as hydrated alumina, Arizona test dust, and flame-generated acetylene soot. Accumulated mass and pressure drop for each in-duct sampler is correlated to the full-scale radial filter accumulated mass from initial to 10 in w. c. of loading. SEM imaging of samples at 25%, 50%, 75% and 100% loading verifies particle sizes with instrumentation used, revealing filter clogging resulting from particle impaction and interception. The U.S Department of Energy requires prototype nuclear-grade HEPA filters to be qualified under ASME AG-1 standards. The data obtained can be used to determine baseline performance characteristics on pleated radial filter medium for increased loading integrity and lifecycle endurance.

No description available.

Master´s thesis deals with the issue of internal microclimate of clean rooms. The experimental part focuses on aerosol and microbial microclimate. Different operating and intervention rooms were measured and then evaluated whether the cleanroom would comply with the standard cleanliness class even in normal operation after previous validations. The microbial examination of different clean spaces investigated the extent to which the exact passive fall method and its evaluation were time-dependent. From the data the correct desing of the air-conditioning system and its subsequent realization and regultion were verified. The theoretical part describes requirements for clean rooms according to SÚKL-LEK 17 and ČSN EN ISO 14644-1. In addition, a detailed methodology of the procedure of air-conditioning implementation is elaborated to the final validation and testing of clean rooms.

The work describes an air conditioning and circulation system of a clean room environment in of a semiconductor production site. It is based on given requirements for air cleanness, temperature preasure and relative moisture. The first half of the work describes the way the system should work, classification of construction and operation of the site. The second half describes the calculations of the given parameters on which the system is designed. The calculations deal with - Air exchange and maintaining the required parameters - Designing the muti stage air filtration system - Designing the air flow speed, intake and outlet parameters of the air conditiong distribution system - Desingning the air conditioning units and their possitioning in the utility room

Today, a significant portion of individuals’ time is spent indoors, estimated at approximately 90% of their total time. This raises concerns about the transmission of Coronavirus Disease 2019 (COVID-19) instigating Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and similar viruses and highlights the critical role of ventilation systems in indoor environments, which this study aims to investigate. Narrowing the focus to healthcare facilities, particularly hospitals in Sweden, the study includes the importance of ventilation systems in safeguarding the health safety and well-being of patients, healthcare workers in hospitals. To effectively combat the spread of the SARS-CoV-2 virus, it is crucial to have a thorough understanding of its viral characteristics, with a specific centre on airborne transmission size, virus longevity, and quantum of infection. Furthermore, it is essential to recognize the major impact of ventilation rate, thermodynamic factors such as temperature and humidity, as well as pollutants in effectively mitigating the transmission of SARS-CoV-2 and similar pathogens.  The comprehensive findings of this literature review underscore that, for hospitals in Sweden, a Heat Recovery Ventilation (HRV) system incorporating a plate heat exchanger is the most suitable ventilation system for this specific objective. Moreover, the recommended ventilation strategy is specifically tailored for implementation in wards or isolated rooms, where it is ideal for the incoming air to originate from the patient’s room floor, while the exit point is preferably located near or at the ceiling. In the context of this study, identified effective solutions involve the utilization and combination of high-efficiency filters and ultraviolet (UV) technology installed within ventilation system unit, particularly when an air recirculation system is used. Additionally, the implementation of RM3 (Rheem’s third generation products) UV-C technology for indoor use can be achieved without considerable intervention in ventilation system, depending on the type of ventilation system being utilized. In summary, this study enhances understanding of the complex relationship between ventilation systems, COVID-19 transmission and similar diseases, the optimization of thermodynamic factors, and selection of effective and practical measures. It provides valuable insights for designing effective ventilation strategies across various indoor environments, with a specific attention on healthcare facilities. / Idag spenderas en betydande del av individers tid inomhus, uppskattningsvis cirka 90% av deras totala tid. Detta väcker oro över överföringen av Coronavirussjukdom 2019 (COVID-19), som initierar Svårt Akut Respiratoriskt Syndrom Coronavirus 2 (SARS-CoV-2) och liknande virus och belyser den kritiska rollen som ventilationssystem spelar i inomhusmiljöer, som denna studie syftar till att undersöka. Genom att begränsa fokus till vårdinrättningar, särskilt sjukhus i Sverige, inkluderar studien vikten av ventilationssystem för att säkerställa hälsosäkerheten och välbefinnandet för patienter och vårdpersonal på sjukhus. För att effektivt bekämpa spridningen av SARS-CoV-2-viruset är det viktigt att ha en grundlig förståelse för dess virala egenskaper, med ett specifikt fokus på luftburen överföringsstorlek, viruslivslängd och infektionsmängd. Dessutom är det viktigt att identifiera den stora inverkan av luftomsättningstakt, termodynamiska faktorer som temperatur och fuktighet samt föroreningar för att effektivt minska överföringen av SARS-CoV-2 och liknande patogener. De omfattande resultaten av denna litteraturstudie understryker att värmeåtervinningsventilationssystem (HRV) med plattvärmeväxlare är det mest lämpliga ventilationssystemet för sjukhus i Sverige för detta specifika mål. Dessutom är den rekommenderade ventilationsstrategin speciellt anpassad för implementering på avdelningar eller isolerade rum, där den är idealisk för att inkommande luft ska komma från patientens rumsgolv, medan utgångspunkten företrädesvis är placerad nära eller i taket. I samband med denna studie involverar identifierade effektiva lösningar, användning och kombination av högeffektiva filter och ultraviolett (UV)-teknik installerad i ventilationssystemenhet, särskilt när ett luftcirkulationssystem används. Dessutom kan implementeringen av RM3 (Rheems tredje generationens produkter) UV-C-teknik för inomhusbruk uppnås utan betydande ingrepp i ventilationssystem, beroende på vilken typ av ventilationssystem som används. Sammanfattningsvis ökar denna studieförståelse för det komplexa förhållandet mellan ventilationssystem, COVID-19-överföring och liknande sjukdomar, optimering av termodynamiska faktorer och val av effektiva och praktiska åtgärder. Den ger värdefulla insikter för att utforma effektiva ventilationsstrategier i olika inomhusmiljöer, med särskild uppmärksamhet på vårdinrättningar.

Activation of mammalian stress responsive pathways by plant secondary metabolites may contribute to the protection against certain chronic diseases afforded by fruit and vegetable consumption. This work focuses on the identification of plant compounds that activate the stress-responsive enzyme quinone reductase (QR) by stabilizing the transcription factor NF-E2 related factor-2 (Nrf2). Screening methanolic extracts of plants from Western Canada for QR induction in a mouse hepatoma cell line (Hepa-1c1c7) led to the identification of twenty-one extracts capable of doubling the activity of QR. Bioassay-guided fractionation of six extracts led to the identification of novel classes of compounds with QR-inducing activity including fatty-acid derived polyacetylenes, phthalides, and cannabinoids. Studies using low molecular weight thiols and the recombinantly expressed protein Keap1, the principal negative regulator of Nrf2, supported a mechanism of QR activation involving covalent modification of Keap1 cysteines for the polyacetylenes and phthalides. Analysis of transcriptional changes in response to treatment with a panel of QR-inducing compounds provided strong support for Nrf2 activation by the polyacetylene (3S,8S)-falcarindiol and the isothiocyanate (R)-sulforaphane and weaker support for the compounds (3R,8S)-falcarindiol, 6-isovaleryl-umbelliferone (6-IVU) and (Z)-ligustilide. Additionally, transcript level analyses supported a role for the aryl-hydrocarbon receptor in QR-activation by (3R,8S)-falcarindiol, (Z)-ligustilide, (R)-sulforaphane, 6-IVU and cannabidiol and suggested that treatment with polyacetylenes with a (3R)-configuration, (Z)-ligustilide and 6-IVU causes substantial changes in the expression of genes associated with lipid homeostasis and energy metabolism. As a whole, this work provides evidence that compounds that activate QR (and Nrf2) are widely distributed in the Canadian flora. However, of these QR activators, few are active at concentrations that are expected to be achieved through dietary consumption. Nevertheless, the most exceptional compounds isolated in this work, the compounds (3S,8S)-falcarindiol and epoxyfalcarindiol are highly potent and appear to be or are expected to be specific for activating Nrf2 and thus warrant attention with respect to dietary implications and as drug candidate leads.

No description available.