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Aerosol particles have profound impacts on human health, atmospheric radiation, and cloud microphysics and these impacts are strongly dependent on particle sizes. However, formation and growth of atmospheric particles are currently not well understood. In this work, laboratory and theoretical studies have been performed to investigate the formation and growth of atmospheric particles. The first two parts of the dissertation are a laboratory investigation of new particle formation and growth, and a theoretical study of atmospheric molecular complexes and clusters. The nucleation rate was considerably enhanced in the presence of cis-pinonic acid and ammonia. The composition of the critical cluster was estimated from the dependence of the nucleation rate on the precursor concentration and the time evolution of the clusters was then simulated using molecular dynamic simulations. Results from quantum chemical calculations and quantum theory of atoms in molecules (QTAIM) reveal that formation of strong hydrogen bonding between an organic acid and sulfuric acid is likely responsible for a reduction of the nucleation barrier by modifying the hydrophobic properties of the organic acid and allowing further addition of hydrophilic species (e.g., H2SO4, H2O, and possibly NH3) to the hydrophilic side of the clusters. This promotes growth of the nascent cluster to overcome the nucleation barrier and thus enhances the nucleation in the atmosphere. The last part of this dissertation is the laboratory investigation of heterogeneous interactions of atmospheric carbonyls with sulfuric acid. Direct measurement has been performed to investigate the heterogeneous uptake of atmospheric carbonyls on sulfuric acid. Important parameters have been obtained from the time-dependent or timeindependent uptake profiles. The results indicated that the acid-catalyzed reactions of larger aldehydes (e.g. octanal and 2, 4-hexadienal) in sulfuric acid solution were attributed to aldol condensation in high acidity. However such reactions do not contribute much to secondary organic aerosol (SOA) formation due to the low acidity under tropospheric conditions. On the other hand, heterogeneous reactions of light dicarbonyl such as methylglyoxal likely contribute to SOA formation in slightly acidic media. The reactions of methylglyoxal in the atmospheric aerosol-phase involve hydration and subsequent polymerization, which are dependent on the hygroscopicity, rather than the acidity of the aerosols.

Mud acid, which is composed of HCl and HF, is commonly used to remove the formation damage in sandstone reservoirs. However, many problems are associated with HCl, especially at high temperatures. Formic-HF acids have served as an alternative of mud acid for a long period. Several factors may influence the outcome of an acidizing job in sandstone formations. In this research, effects of mineralogy, temperature, and HF concentration were studied. Various clay minerals (kaolinite, chlorite, and illite) were examined to react with formic-HF acid mixtures which contain different concentrations of HF. Coreflood experiments on sandstone cores featured by different mineralogy with dimensions of 1.5 in. x 6 in. were also conducted at a flow rate of 5 cm^3/min. Formic or acetic acids were used in preflush stage to remove the carbonates. A series of formic-HF acid mixtures with different ratios and concentrations were tested, and temperature varied from 77 to 350 degrees F. Inductively coupled plasma (ICP), scanning electron microscopy (SEM) and 19F nuclear magnetic resonance (19F NMR) were employed to follow the reaction kinetics and products. Besides, acetic-HF acid system, which is another important alternative of mud acid, was also investigated to compare with formic-HF acids. The species and amounts of reaction products of different clay minerals in organic-HF acids depend on mineral type, acid composition and ratio, and this is further confirmed by coreflood experiments, in which sandstone cores with different mineral compositions give quite different responses to the same acid mixture. As preflush, formic acid becomes more effective in removing carbonate minerals in sandstone cores at higher temperatures. In main flush stage, more concentrated HF can react with more clay minerals, but can also cause higher risk of CaF2 precipitate. Both formic-HF and acetic-HF acids are much milder than mud acid. When reacting with clay minerals, there is no big difference in the behaviors of 13 wt% acetic-HF acids and 9 wt% formic-HF acids, as long as the HF concentrations are the same.

Diploma thesis deals with the problem of observation of controlled and spontaneous fermentation influence on the organic acids content in species of wine (Ruland blue) originated in subregion of Velké Pavlovice. Initial conditions of analysis (introduced in [41] and in materials concerning chromatographic column) were changed during lasting of experiment in such manner to get the most precise analysis of the wine sample. Enzyme Rapidase Excolor was added in the beginning of both types of fermentation plus yeasts were added at the controlled fermentation. Analysis of four organic acids was done; these were tartaric, malic, lactic and citric acid. High performance liquid chromatography (HPLC) with UV detection method was used to determine concentration of each acid. Wine was processed by two technological methods – by spontaneous and controlled fermentation. Each of the process differed in the organic acids content. Concentration of tartaric acid varied from 1,63 g/l to 6,43 g/l during spontaneous fermentation process. Decrease was caused by biological processes taking place. Concentration of citric acid was not almost influenced by the process of fermentation. Due to malolactic fermentation being in progress, decrease in malic acid concentration (from 6 g/l to 1,87 g/l) and increase in lactic acid concentration was observed. Concentration of tartaric acid varies as well during controlled fermentation. Biggest increase in concentration was observed at hour 214 of the experiment when the process of fermentation was supported by addition of lactic bacteria. Due to malolactic fermentation being in progress, decrease of malic acid concentration and increase of lactic acid concentration was observed similar to simultaneous fermentation. Concentration of citric acid was constant during controlled fermentation. Experiment proved that there is higher content of observed organic acids during controlled fermentation than during processes of spontaneous fermentation.

Phosphorus (P) is poorly soluble in most soils and, thus, has poor plant uptake efficiency. AVAIL® and Carbond P (CBP) are new fertilizer products shown to increase P use efficiency (PUE) and increase crop yields when grown in P limiting soils. Carbond P has specifically been seen to increases P uptake and crop yields in soils low in P, although effectiveness in regards to soil organic matter is unknown. The objectives of these studies were to determine if the mode of action for these products is related to physiological response, to determine if Carbond P is toxic to plant roots when in direct contact at high rates, and determine the limitations of Carbond P in regards to biomass (yield), P uptake and concentration. We used a hydroponic study to compare CBP to AVAIL in evaluating plant toxicity and plant philological response. AVAIL and CBP were also compared to ammonium polyphosphate (APP) at pH 6 or 8 for hydroponically grown maize (Zea mays L.). Additionally, a glasshouse study evaluated the PUE of CBP with soil in which maize was grown. Soils were moderate or high in organic matter, with 0, 5, 15, 45, or 135 kg P2O5 ha-1 applied as either APP or CBP. Both studies showed that CBP is a suitable PUE enhancing fertilizer. In the greenhouse study, the high organic matter soil revealed that both CBP and APP fertilization resulted in similar increases in biomass yield and P concentration and uptake. However, in the moderate organic matter soil, biomass and total P uptake was significantly greater for CBP than APP at the two lowest P rates of fertilization and significantly higher for APP than CBP at the highest P application rate. In the hydroponic study, neither AVAIL nor CBP had any positive or adverse effects on the plants as compared to APP. These results, coupled with this and previous soil-based greenhouse and field studies with AVAIL and CBP, show that the increase in PUE is not a physiological growth stimulant response, but rather likely the result of impacts on P solubility in the soil. However, the presence of high organic matter in the soil seemed to negate the effects of the organic acid bonded P used in Carbond P. We conclude that CBP, and possibly other organic acid based fertilizers, can assist in furthering agricultural goals, as well as environmental responsibility with these known limits.

The large scale nitric acid oxidation of common sugars into their corresponding aldaric acids is being investigated as an important source of potentially useful components for industrial applications such as polymers. This thesis details the development of an Ion Chromatography (IC) method for the analysis of these oxidation mixtures and related samples from the work-up and purification processes. The method was developed for use with a Dionex ICS2000 IC system equipped with an AS11-HC column and utilising suppressed conductivity detection. IC proved to be a useful, versatile and straightforward method of studying the reactions and their products. The detected ions include but are not restricted to the anionic salt forms of: D-Glucaric acid, Xylaric acid, Mannaric acid, D-gluconic acid and both keto forms of the same, D-xylonic acid, D-mannonic acid, glycolic acid, oxalic acid, tartaric acid and tartronic acid. Nitrate from the nitric acid used in the oxidation is often observed. The results compare favorably to GC-MS and HPLC analysis of similar samples. An overview of the theory and operation of the instrument along with the method development and results from application to the oxidation mixtures and related samples are presented. As part of the investigation into the range of utility of IC for studying these reactions, a study was made of the retention behaviour of a large number of simple and low molecular weight (LMW) carboxylic acids eluted by the ion chromatography system in use. The results of this study are included with an explanation of the major factors affecting anion retention on the column

Organic acids, including L- and D-lactate, explain most but not the entire elevated anion gap in diarrhea-associated metabolic acidosis. Also, D-lactate has been implicated in the neurological symptoms associated with this condition. Less-common organic compounds may influence the anion gap and neurological symptoms. This research aimed to characterize and attempt to identify a previously unidentified compound, Compound X, first noted in diarrheic acidotic calves with elevated anion gap (Omole, 1999).<p> High performance liquid chromatography (HPLC) was used to measure Compound X in biological fluids from diarrheic and healthy calves; diarrheic piglets, foals, and human infants; and calves experimentally infused with saline or acid. Attempts were made to identify Compound X using HPLC with tandem and Fourier-transform mass spectrometry.<p> Compound X was significantly higher in diarrheic calf serum (p<0.001) and lower in feces (p<0.001) and rumen fluid (p<0.001) than those fluids from healthy calves. Compound X in serum from acid-infused calves (median peak area ratio = 1.5 1.9) was lower than that of diarrheic calves (median = 4.8) and only slightly greater than that of healthy calves (median = 1.2). Serum Compound X correlated with serum D-lactate in diarrheic and healthy calves combined; however, no such correlation was observed in acid-infused calves. Conversely, a relationship between Compound X and neurological disturbance was present in acid-infused calves, but not in diarrheic calves. In other species, Compound X was highest in diarrheic infants and lowest in diarrheic piglets. Although mass spectrometry and database library searches revealed several compounds as putative matches for Compound X, none of the compounds made sense within the context of acidosis and mammalian biological fluids. Therefore, the identity of Compound X remains unknown.<p> Compound X has been established as a ubiquitous compound(s) present in the biological fluids of mammals. Compound X may be a normal intestinal compound or bacterial metabolite that crosses the intestinal epithelium during diarrhea. In spite of this, Compound X was associated with the neurological manifestations of D-lactic acidosis. Compound X`s identity was not determined, and some reasons for this and future directions are discussed.

Organic acids, including L- and D-lactate, explain most but not the entire elevated anion gap in diarrhea-associated metabolic acidosis. Also, D-lactate has been implicated in the neurological symptoms associated with this condition. Less-common organic compounds may influence the anion gap and neurological symptoms. This research aimed to characterize and attempt to identify a previously unidentified compound, Compound X, first noted in diarrheic acidotic calves with elevated anion gap (Omole, 1999).<p> High performance liquid chromatography (HPLC) was used to measure Compound X in biological fluids from diarrheic and healthy calves; diarrheic piglets, foals, and human infants; and calves experimentally infused with saline or acid. Attempts were made to identify Compound X using HPLC with tandem and Fourier-transform mass spectrometry.<p> Compound X was significantly higher in diarrheic calf serum (p<0.001) and lower in feces (p<0.001) and rumen fluid (p<0.001) than those fluids from healthy calves. Compound X in serum from acid-infused calves (median peak area ratio = 1.5 1.9) was lower than that of diarrheic calves (median = 4.8) and only slightly greater than that of healthy calves (median = 1.2). Serum Compound X correlated with serum D-lactate in diarrheic and healthy calves combined; however, no such correlation was observed in acid-infused calves. Conversely, a relationship between Compound X and neurological disturbance was present in acid-infused calves, but not in diarrheic calves. In other species, Compound X was highest in diarrheic infants and lowest in diarrheic piglets. Although mass spectrometry and database library searches revealed several compounds as putative matches for Compound X, none of the compounds made sense within the context of acidosis and mammalian biological fluids. Therefore, the identity of Compound X remains unknown.<p> Compound X has been established as a ubiquitous compound(s) present in the biological fluids of mammals. Compound X may be a normal intestinal compound or bacterial metabolite that crosses the intestinal epithelium during diarrhea. In spite of this, Compound X was associated with the neurological manifestations of D-lactic acidosis. Compound X`s identity was not determined, and some reasons for this and future directions are discussed.

No description available.

Ethanol tolerance in Saccharomyces cerevisiae is a complex polygenic trait. As a toxin, ethanol damages multiple cell constituents as well as being both a substrate and product of the metabolism of S.cerevisiae. This complexity has made ethanol tolerance difficult to study. Deletion screens have identified hundreds of genes that impair ethanol tolerance by their absence and hence might help survival in high ethanol environments. Similarly, expression studies have revealed genes that respond to ethanol shock, but it is unclear whether those genes are likely targets for improvement of ethanol tolerance in strains growing normally. In addition, those yeasts that are currently commercially exploited for their high ethanol tolerance in the brewing and bioethanol industries are commonly aneuploid or polyploid which makes it difficult to correlate particular features of their genotype with the ethanol tolerant phenotype. Experimental evolution can reveal genetic changes that change competitive fitness. It is practical to run numerous competitions in parallel between isogenic S.cerevisiae strains for hundreds of generations under ethanol stress, after which whole genome sequencing can identify the genetic changes. Fluorescent tagging of those strains can reveal small changes in population dynamics. We propagated 144 populations in batch culture for between 100 and 200 generations under 4 ethanol regimes (0%, 4.5%, 6.5% and ramped 0-10%). We monitored the progress of evolution by using mixtures of two fluorescently tagged, but otherwise isogenic, haploid, hoΔ (site-specific endonuclease deletant) founder strains (DeLuna et al 2008). Population dynamics measured using fluorescently labelled strains indicated that changes had occurred in competitive fitness due to adaptive evolution. Cell-size measurement and flow cytometry showed that evolved populations were diploid or triploid and the transition to higher ploidy occurred more rapidly with increasing ethanol stress. During the experimental evolution three strains evolved the capacity to grow on organic acids. We have sequenced the complete genomes of eight evolved strains. These strains are confirmed as being diploid, but not aneuploid. Sequencing of evolved strains revealed mutations that have not been previously characterised in deletion or expression studies of ethanol or organic acid tolerance in S.cerevisiae. Both increasing ploidy, to produce triploids as well as diploids, and the acquisition of organic acid tolerance under ethanol stress are unexpected outcomes that have implications for future work.