Analysis of Volatile Organic Compounds: Petroleum Emissions and Microbial Degradation

Volatile organic compounds (VOCs) are abundant in nature and can occur in various forms in a wide variety of sources. Petroleum is one of the major sources of VOCs. Petroleum being the most widely used energy resources of the world, often released to the environment due to emission and leakage or accidental spillage during exploration, transportation and manufacturing. Once released to the environment, petroleum poses a serious threat to the environment due to some of its toxic organic components. Therefore, the analysis of petroleum is critical to understand its effect on the environment and remediation. This dissertation is focused on the analysis of VOCs from petroleum to understand their emission characteristics and microbial degradation. In Chapter 2, the effect of ethanol on the evaporative emission characteristics of ethanol-blended medium and high-density gasoline was studied by measuring the vapor phase composition at different temperatures (room temperature, 38, and 49 °C) using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatographymass spectrometry (GC-MS). A standard mixture of gasoline was prepared based on the detailed hydrocarbon analysis of high-density gasoline by mixing 16 selected compounds and tested. Ethanol was added in different percentages to prepare E0, E10, and E20 (0, 10 and 20 v/v % ethanol) fuel samples. The results obtained from GC-MS were calculated in terms of percentage compositions of compounds separated into four groups (paraffins, iparaffins, monoaromatics, and mononaphthene). The results showed the decrease of vapor phase composition of monoaromatics with the increasing ethanol percentages for most of the tested fuels at all tested temperatures. Similar results were also obtained in paraffin and i-paraffins except for i-paraffins in standard and high-density gasoline and paraffins in medium-density gasoline at room temperature. The percentage decrease is much higher from 0 % to 20 v/v % ethanol containing fuel. In Chapter 3, we investigated the biodegradation ability of petroleum hydrocarbons from kerosene in tryptic soy broth (TSB) and minimal culture media by Bacillus amyloliquefaciens. Two isolates (1BA and 1D3) of B. amyloliquefaciens were grown in TSB and minimal media supplemented with 1% kerosene to understand if the isolates could co-metabolize (or metabolize in case of minimal media) the petroleum hydrocarbons from kerosene by utilizing them. The degradation was measured using GCMS. The result showed the decrease of residual kerosene to below 50% after 4 and 6 days by 1BA and 1D3 respectively. However, beyond this period, the results for control showed more degradation compared to media containing isolates. Although the residual percentage kerosene was comparatively less, meaning more degradation by 1BA and 1D3 compared to control in minimal media, the difference was comparatively low to determine whether the degradation was due to bacterial isolates or not. Further studies were done in terms of iturin A and surfactin biosurfactant production using UHPLC with diode array detection to find out the degradation of petroleum hydrocarbons if a correlation between biosurfactant production and hydrocarbon utilization could be established or not. The UHPLC results confirmed the production of surfactin by only 1D3, but no iturin A by any isolates. Based on the results, 1D3 produced surfactin both in the presence and absence of kerosene in TSB media. However, the concentration in absence of kerosene was much higher (more than double) than in presence of kerosene. Although no surfactin isoform peaks were produced by 1D3 in the presence of kerosene in minimal culture media, it gave some peaks, but very low in intensity in the absence of kerosene, hence concentration was seemed to be very low when compared to 100 ppm standard solution. Since UHPLC results did not find any correlation between surfactin production and kerosene utilization, based on the result, it is less likely that the studied bacteria isolates were utilizing the kerosene to grow and producing lipopeptide surfactants. In Chapter 4, we developed an analytical technique using a commercial dry herb vaporizer (vape) to be used for sample heating and direct extraction of analyte compounds from the headspace of the vape using headspace solid-phase microextraction (HS-SPME) coupled with GC-MS. VOCs from three samples (horseradish, cinnamon, and gasoline spiked soil) were analyzed, and the results were compared with the traditional headspace method. Although comparable results were obtained in term of relative area percentage for both methods, the vape method was found to be more concentrated, since the abundance in the total ion chromatogram obtained for identified peaks were much higher than traditional headspace method

Factors influencing the knowledge and attitude of nurses towards adverse drug reaction reporting in a teaching hospital

Background: Adverse Drug Reactions (ADR) are common in hospitalized patients. Nursing staff spends most time in patient care placing them at a key it position to recognize ADRs at the earliest. However, ADR reporting practices among nurses is very poor. We conducted this study to identify the factors affecting knowledge and attitude of nurses in a teaching hospital towards ADR reporting.Methods: A pre-tested and validated questionnaire was used. Correct responses in the knowledge section were awarded one mark and incorrect responses were given zero. Based on responses to attitude questions on a 5-point Likert scale, best attitude was scored five and least preferred attitude was given one point. Total knowledge and attitude scores were analyzed with regards to age, gender, educational qualification, average weekly working hours, total working experience in years and past experience with ADRs and ADR reporting. Knowledge scores were also correlated with attitude scores.Results: Knowledge level was poor with 48.29±23.85% average score while attitude of the respondents was reasonable with 65.69±10.05% average scores. The knowledge scores and attitude scores of BSc degree holders was higher than GNMs and ANMs (p<0.001). Those who had independently identified an ADR had higher knowledge scores (p<0.01) and more positive attitude (p<0.001). Attitude scores also had a significantly strong correlation with knowledge level of the respondents (r=0.72).Conclusions: Knowledge about ADR reporting is the most important factor determining the attitude towards ADR reporting. Increasing awareness would be pivotal in changing attitude and thus, improving reporting rates

Radical Chemistry in a Femtosecond Laser Plasma: Photochemical Reduction of Ag+ in Liquid Ammonia Solution

Plasmas with dense concentrations of reactive species such as hydrated electrons and hydroxyl radicals are generated from focusing intense femtosecond laser pulses into aqueous media. These radical species can reduce metal ions such as Au3+ to form metal nanoparticles (NPs). However, the formation of H2O2 by the recombination of hydroxyl radicals inhibits the reduction of Ag+ through back-oxidation. This work has explored the control of hydroxyl radical chemistry in a femtosecond laser-generated plasma through the addition of liquid ammonia. The irradiation of liquid ammonia solutions resulted in a reaction between NH3 and OH·, forming peroxynitrite and ONOO−, and significantly reducing the amount of H2O2 generated. Varying the liquid ammonia concentration controlled the Ag+ reduction rate, forming 12.7 ± 4.9 nm silver nanoparticles at the optimal ammonia concentration. The photochemical mechanisms underlying peroxynitrite formation and Ag+ reduction are discussed

Arthritis of leprosy

An inflammatory polyarthritis has been previously described in leprosy but accounts of the clinical characteristics have varied. All patients with joint symptoms admitted to a leprosy centre over 5 months were examined by a rheumatologist. Of 48 acute admissions, 20 (42%) had a symmetrical polyarthritis affecting the wrists and fingers. This was strikingly similar to RA in appearance. The arthritis occurred exclusively in patients with reactions mainly during anti-mycobacterial treatment. The clinical features of the joint disorder were identical in Type I (associated with alterations in immune status) and Type II (erythema nodosum leprosum) reactions. Synovial tissue from one patient revealed no mycobacteria. Four of five hand X-rays suggested small erosions of the finger joints

Electronic structure of spin 1/2 Heisenberg antiferromagnetic systems: Ba_2Cu(PO_4)_2 and Sr_2Cu(PO_4)_2

We have employed first principles calculations to study the electronic structure and magnetic properties of the low-dimensional phosphates, Ba2Cu(PO4)2 and Sr2Cu(PO4)2. Using the self-consistent tight-binding lin- earized muffin-tin orbital method and the Nth order muffin-tin orbital method, we have calculated the various intrachain as well as the interchain hopping parameters between the magnetic ions Cu2+ for both the com- pounds. We find that the nearest-neighbor intrachain hopping t is the dominant interaction suggesting the compounds to be indeed one dimensional. Our analysis of the band dispersion, orbital projected band struc- tures, and the hopping parameters confirms that the Cu2+-Cu2+ super-super exchange interaction takes place along the crystallographic b direction mediated by O-P-O. We have also analyzed in detail the origin of short-range exchange interaction for these systems. Our ab initio estimate of the ratio of the exchange inter- action of Sr2Cu(PO4)2 to that of Ba2Cu(PO4)2 compares excellently with available experimental results.Comment: 6 pages, 4 figure

The Importance of Attributional Trust to Corporate Reputation

This article proposes the simplified trust-reputation model that relates attributional trust and issue resolution to corporate reputation. In effect, individuals on a project are very forgiving of supply chain members with regard to issues because of concern for their company&#039;s reputation. Hence, while trust may vary, there was no breakdown in trust because this would affect their company&#039;s reputation as a good partner. Furthermore, although there was a reported variance in trust by the project managers, it did not affect the project&#039;s outcome, but it did affect the ease of doing business

Adaptive sparse Galerkin methods for vibrating continuous structures

Adaptive reduced-order methods are explored for simulating continuous vibrating structures. The Galerkin method is used to convert the governing partial differential equation (PDE)into a finite-dimensional system of ordinary differential equations (ODEs) whose solution approximates that of the original PDE. Sparse projections of the approximate ODE solution are then found at each integration time step by applying either the least absolute shrinkage and selection operator (lasso) or the optimal subset selection method. We apply the two projection schemes to the simulation of a vibrating Euler–Bernoulli beam subjected to nonlinear unilateral and bilateral spring forces. The subset selection approach is found to be superior for this application, as it generates a solution with similar sparsity but substantially lower error than the lasso

Segment Oriented Compression Scheme for MOLAP Based on Extendible Multidimensional Arrays

Many statistical and MOLAP applications use multidimensional arrays as the basic data structure to allow the efficient and convenient storage and retrieval of large volumes of business data for decision making. Allocation of data or data compression is a key performance factor for this purpose because performance strongly depends on the amount of storage required and availability of memory. This holds especially for data warehousing environments in which huge amounts of data have to be dealt with. The most evident consequence of data compression is that it reduces storage cost by packing more logical data per unit of physical capacity. And improved performance is a net outcome because less physical data need to be retrieved during scan-oriented queries. In this paper, an efficient data compression technique is proposed based on the notion of extendible array. The main idea of the scheme is to compress each of the segments of the extendible array using the position information only. We compare the proposed scheme for different performance issues with prominent compression schemes.</p