Metal organic frameworks (MOFs) and metal oxide-MOF composites were investigated for adsorption and oxidation of carbon monoxide. Metal oxides were successfully included in MOFs via both impregnation and encapsulation. UiO-66, a zirconium-based MOF, was impregnated with magnesium or cobalt oxide. Cobalt oxide in UiO-66 increases the room temperature CO capacity and shows increased adsorption at 65°C due to strong cobalt-CO interactions. Titania and magnetic nanoparticles were encapsulated in HKUST-1, a copper-based MOF. Including titania in HKUST-1 lowers the CO oxidation onset temperature by over 100°C compared with HKUST-1, and the composite reaches complete conversion by 250°C. HKUST-1 with magnetic nanoparticles shows enhanced structural stability and increased room temperature adsorption of CO and hexane. MOF-74, an isostructural family with coordinatively unsaturated metal centers of cobalt, magnesium, nickel, or zinc, was investigated for the metal center’s impact on stability and adsorption. Pre-treatment conditions to optimize accessibility were found that maximize solvent removal while retaining structural integrity. The impact of air exposure on equilibrium CO capacity was investigated, and these predictions were compared to dynamic conditions, separating CO from nitrogen or air at room temperature. The cobalt analog loses only 25% of its CO capacity with air exposure, retaining higher capacity than the other analogs under ideal conditions. Unlike cobalt, the magnesium analog does not follow the predicted trends with air exposure, having higher dynamic capacities with pre-exposed samples. Under all dynamic conditions, the nickel analog oxidized a portion of the carbon monoxide feed.

The investigation of the atmospheric fate and transport of semi-volatile organic compounds (SOCs) often requires the sampling of large volumes of air (>100 m3) in a relatively short period of time. Conventionally high-volume pumps are not suitable for remote areas without access to reliable network power. We have developed a flow through sampler for such situations. It consists of a horizontally-oriented flow-tube, that can collect gaseous and particle-bound SOCs from large volumes of air by turning into the wind and having the wind blow through a porous sampling medium such as polyurethane foam. Through both indoor and outdoor experiments, we quantified its air sampling rate (through battery operated anemometers inside and outside of the flow tube), its sampling efficiency (by theoretical plate number analysis of the break-though curves for PCBs, PAHs, OCPs and PBDEs), and its accuracy (by comparison of concentrations, time trends, temperature dependences and isomer ratios with those obtained by conventional high-volume sampling) under conditions of constant and variable meteorological conditions (wind speed, temperature). The flow-through sampler was deployed to monitor SOC concentrations at a remote Chinese research station located close to Nam Co Lake, Tibet. During the campaign, fifteen 1 month-long samples were taken, corresponding to sample volumes between 5,000 and 20,000 m3. Despite those large sample volumes, only HCB and HCHs experienced break-through, but application of frontal chromatograph theory allows the estimation of breakthrough-corrected air concentrations even for those relatively volatile SOCs. The pesticide levels at Nam Co are generally very low. Most pesticides had higher levels during summer, resulting in a strong temperature dependence. This is correlated with air mass origin across the Himalayas in the Gangetic plains of India and Bangladesh. The flow through sampler constitutes a feasible method for reliably and quantitatively collecting SOCs from large air volumes.

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Bakgrund: Generellt genomförs operationer på en operationssal med anpassade förutsättningar samtsterila och aseptiska förhållanden. Syftet är att bibehålla den rekommenderade mikrobiologiskarenhetsgraden i luften och förebygga postoperativa infektioner. Bakteriebärande partiklar i luften kanuttryckas i colony forming units per kubikmeter (CFU/m³). Mindre operationer genomförs även påmottagningsrum men det saknas kunskap om CFU/m³ i dessa vårdmiljöer. Syfte: Syftet var att jämföra CFU/m³ i en operationssal och ett mottagningsrum vid polikliniskaoperationer samt kartlägga faktorer som kan påverka CFU/m³. Metod: Studien är en icke-experimentell tvärsnittsstudie med kvantitativ metod och observationer avkvalitativa data. Totalt genomfördes 20 aktiva luftmätningar under pågående operationer, varav tio ien operationssal samt tio i ett mottagningsrum. Data analyserades med deskriptiv och analytiskstatistik. För att beskriva skillnader mellan de två grupperna valdes det icke parametriska MannWhitney U test samt Spearman's rangkorrelation för analys av samband mellan CFU/m³ och övrigavariabler. Multivariabel regression användes för att undersöka vilka av variablerna som hade enoberoende effekt på CFU-värdet.Resultat: Av 20 aktiva luftmätningar påvisades ett högre CFU/m³ (p <0,001) och en högrerumstemperatur (p <0,001) i mottagningsrum jämförelsevis med operationssal. Vårdmiljön hade enoberoende effekt på CFU-värdet (p <0,05). Variablerna antal personer och antal dörröppningar bidroginte signifikant till regressionsmodellen. Slutsats: Följande studie kan konstatera att CFU/m³ var högre i mottagningsrummet än ioperationssalen. Huruvida CFU-värdet har en klinisk betydelse för postoperativa infektioner eftermindre polikliniska operationer i mottagningsrum behöver undersökas i framtida forskning. / Bakgrund: Verksamheten utförs i allmänhet i en operationssal med anpassade förhållanden, samt sterila och aseptiska förhållanden. Att upprätthålla mikrobiologisk renhet i luften är ett sätt att förhindra infektioner på operationsstället (SSI). Luftburna bakteriepartiklar uttrycks i kolonibildande ledningar per kubikmeter (CFU/m³). Mindre kirurgiska ingrepp utförs också i klinikbaserade procedurrum men det saknas kunskap om nivåerna av CFU/m³. Syfte: Syftet var att jämföra CFU/m³ i en operationssal med ett klinikbaserat ingrepp som utförde kirurgiska ingrepp och undersöka faktorer som kan påverka CFU/m³. Metoder: En ickeexperimental tvärsnittsstudie med en kvantitativ metod och observation av kvalificerade data utfördes. Totalt genomfördes 20 aktiva luftprovtagningar under mindre kirurgiska ingrepp, tio i varje driftsmiljö. Data analyserades med beskrivande och analytisk statistik. Mann-Whitney U-test tillämpades för att jämföra de två grupperna. Spearmans rank-korrelationmeasured korrelationen och flera regressionsanalys användes för att förstå effekterna av två eller flera oberoende variabler på CFU/m³. Resultat: En högre CFU/m³ (p<0,001) och en rumstemperatur (p<0,001) upptäcktes i klinikenbaserade procedurrummet jämfört med operationssalen. Driftsmiljön hade en oberoende på CFU/m³ (s<0,05). Variabler som antal personer och dörröppningar bidrog inte obetydligt. Slutsatser: Denna studie kan fastställa att CFU/m³ var högre i den klinik-baserade förfarandet roomversus operationssalen. Ytterligare forskning behövs för att undersöka om CFU/m³ har en klinisk betydelse för SSI i klinikbaserade procedurrum.

No description available.

The aim of the study was to determine the 13 health risk PAHs (phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, ideno(1,2,3-cd)perylene and coronene; c-PAU highlighted) in the fractions of size-segregated aerosol of the urban air in Ostrava (2012, 2014) and Mlada Boleslav (2013) at low temperatures in winter, and to verify experimentally a sampling artifact, i.e., to quantify PAHs in the gas phase. For the particle size separation high-volume cascade impactor Hi-Vol BGI 900 was used. PAHs were determined by HPLC-FLD/PDA. In Ostrava in 2012 during the winter inversion (up to -25 řC), mean concentration of 13 PAHs in aerosol was 432 ng.m-3 ; in fraction 10 - 1 µm 119 ng.m-3 , 1 - 0,5 µm 185 ng.m-3 , 0,5 - 0,17 µm 91 ng.m-3 , in fraction < 0,17 µm 37 ng.m-3 and in the gaseous phase of min. 40 ng.m-3 . In the most unfavorable day 2. 2. 2012 (-18.6 ř C) reached the 24-hour average of 13 PAHs 890 ng.m-3 , the sum of carcinogenic PAHs 237 ng.m-3 and benzo(a)pyrene 32.3 ng.m-3 . An irregular and different decline of PAHs concentrations after inversion was measured: in fraction 1 - 10 µm 2.8 times, 0.5 - 1 µm 4.2 times, 0.5 - 0.17 µm 4 times and for <0.17 µm up to 7.6 times....

No description available.

Document formatted into pages; contains 115 pages. / Title from PDF of title page. / Original thesis was submitted in HTML and can be accessed at http://www.lib.usf.edu/EDT-db/theses/available/etd-10262001-162331/unrestricted/default.htm / Thesis (M.S.)--University of South Florida, 2002. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The purposes of this research were to determine the efficacy of using the Ogawa]a passive sampling device (PSD) to measure ammonia and to identify significant ammonia sources adjacent to Hillsborough and Tampa Bay. Ninety-four samplers were deployed over a 180-km2 area for two weeks in October 2001. Within the area sampled were located suburbs, an urban center, major highways, port activities, fertilizer manufacturing, wastewater treatment, coal-combustion power plants, warehousing and dairy farming. The sampled locations were arranged in a triangular grid pattern spaced 1.5 km apart. The pattern was designed to locate circular hot spots with a minimum radius of 0.75 km. The minimum, maximum, mean, and median ammonia concentrations were 0.06, 15, 2.0, and 1.5 mg/m3, respectively, and the estimated precision was 16%. Hot spots identified from kriged concentration data coincided with inventoried ammonia sources. / ABSTRACT: The relative bias and precision of the PSD based on collocation with an annular denuder system were (plus or minus) 30 % and 20 %. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

This thesis is an investigation of detecting and quantifying airborne inoculum of Sclerotinia sclerotiorum (Lib.) de Bary to improve the Sclerotinia rot of carrot (SRC) forecast model. A quantitative polymerase chain reaction (qPCR) assay was developed to specifically detect and quantify DNA from airborne ascospores of S. sclerotiorum. The qPCR assay was evaluated on air samples collected using a Burkard Sampler, and showed that ascospores of S. sclerotiorum were specifically detected among a pool of foreign DNA. The concentration of detected ascospores was related to the observed incidence of SRC to suggest a preliminary threshold of 2 to 4 ascospores m-3 of air for SRC development. Evaluation of an Andersen Sampler, the blue plate test (BPT) and the qPCR assay showed that the latter two methods were equally effective in detecting and quantifying ascospores of S. sclerotiorum and consistently detected greater numbers of ascospores than an Andersen Sampler. Three days are required to confirm the presence of S. sclerotiorum using the BPT, while results from the qPCR assay can potentially provide results within five hours of air sampling. The choice of detection method depends on the available resources and need for a quick result. Analysis of data from nine years of air sampling using the BPT indicated that a single air sampling site is sufficient to detect ascospores when counts are low, increasing to two sites during periods when ascospores are detected near threshold levels and crop and environmental conditions are conducive to disease. Chitosan and canopy trimming were evaluated to manage SRC under field conditions. Chitosan reduced area under the disease progress curve (AUDPC) by 55 and 42% in 2009 and 2011, respectively, which was comparable to a standard fungicide. Trimming enhanced chitosan efficacy, reducing AUDPC by 88 and 82% in 2009 and 2011, respectively. Trimming as a stand-alone treatment reduced AUDPC by 66% in 2011. Under controlled environmental conditions, chitosan inconsistently enhanced defense responses against S. sclerotinia. The results show that chitosan has potential to be integrated into SRC management systems, particularly when combined with foliar trimming in years with moderate to high disease risk. / National Research Council of Canada; University of Guelph; Department of Plant Agriculture; Ontario Ministry of Agriculture, Food and Rural Affairs

Isocyanates, aromatic-, aliphatic- and alkanolamines are commonly used in the industry today. Millions of workers in Europe are exposed. The most frequent health symptoms are respiratory and dermal disorder. Due to the health risk most of the compounds in this thesis are regulated by authorities and have occupational exposure limits (OELs). Consequently, reliable and robust air sampling methods are urgently needed. In this thesis dry samplers for isocyanates, aliphatic- and alkanolamines have been developed and evaluated. The isocyanate sampler is now a commercial product (ASSET EZ4-NCP Dry Sampler, Supelco). The samplers were based on a denuder with a filter in series. The denuder and filter were impregnated with di-n-butylamine for the isocyanate sampler and with sulphuric acid for the aliphatic- and alkanolamine sampler. The robustness of the dry samplers was extensively evaluated. This was performed in a climate chamber containing a controlled atmosphere of the studied compounds. New methods based on hydrophilic interaction liquid chromatography (HILIC) coupled with tandem mass spectrometry (MSMS) were developed for determination of aromatic-, aliphatic- and alkanolamines in aqueous solutions. Isocyanates were determined by reversed-phase liquid chromatography MSMS. HILIC in combination with MS is a most powerful system, and highly sensitive determinations, several orders of magnitude below the OELs, of polar compounds present in the work environment can be accomplished. The selected samplers enable sampling during short sampling times and for whole work shifts. The samplers can be stored for months before and after sampling. The performance of the samplers was unaffected by variation in temperature, humidity, flow-rate and pre- and post-sampling of ambient air. Sampling for the compounds studied is now greatly simplified, and assessment of the work environment is facilitated. / <p>At the time of the doctoral defence the following papers were unpublished and had a status as follows: Paper 1: Epub ahead of print; Papers 3-5: Manuscripts</p>