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Dissertations / Theses on the topic 'Total solid and volatile solid'
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1
Huang, Zhanzhao. "Enhanced biogas production by increasing organic load rate in mesophilic anaerobic digestion with sludge recirculation." Thesis, KTH, VA-teknik, Vatten, Avlopp och Avfall, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99354.
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For enhancing anaerobic sludge digestion and biogas recovery, an increase in organic load rate (OLR) from 1.0 to 3.0kgVS/(m3·day) was imposed upon a new anaerobic digestion process combined with a sludge recirculation. The new setup requires a traditional mesophilic anaerobic digester coupled with a centrifuge for maintaining relatively high solid content within the digester. The hypothesis of this study was that increasing continuously OLR from 1.0 to 3.0kgVS/(m3·day) in a pilot-scale anaerobic digester with recycled sludge would not badly influence the digester stability, based on which biogas production would be enhanced. To test this hypothesis, a continuous 73-day study with laboratory experiment was conducted. Due to scarcity of original feeding sludge and its deteriorating quality, OLR had to be increased relied on introduction of extra sludge followed by measurement of total solid (TS) and volatile solid (VS) contents in both feeding sludge and digester sludge, for calculating OLR and examining its variations. To assess the relationship between biogas production and OLR, a measurement of gas yield and methane content was a necessity, performed by applying a biogas flow meter and MSA AUER EX-METER II (P). Moreover, temperature, pH value, volatile fatty acid (VFA) and alkalinity must be tested frequently, for the purpose of preventing system failure. The results demonstrate that the digester succeeded in withstanding an OLR up to 3.15kgVS/(m3·day). Furthermore, an enhancement in biogas yield and methane content were observed after increasing the OLR by introducing extra sludge. Biogas production measurement performed during this study indicated that biogas yield was enhanced by 73%, with a maximum production of 14.5m3/day, when OLR was increased from 2.05 to 3.15kgVS/(m3·day). However, methane content was merely promoted by 10.5%, to the highest value of 63%, with the same increase in OLR. Specific gas production (SGP), as another means of evaluating the relationship between biogas production and OLR, was observed to be 0.65Nm3/kg VSin averagely.
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Dogan, Evrim. "Organic Acid Production From The Organic Fraction Of Municipal Solid Waste In Leaching Bed Reactors." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608043/index.pdf.
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This study was carried out to evaluate the potential of high-rate anaerobic digestion of high-solids organic fraction of municipal solid waste (OFMSW) for the production of organic acids and alcohols in leaching bed reactors (LBRs). For this purpose, two different experimental set-ups, namely Set-1 and Set-2, were operated. In the Set-1, only OFMSW without paper was studied in two identical LBRs, whereas, four identical LBRs, fed with OFMSW with paper and cow manure in different proportions, were operated in the Set-2.
In this study, 50-60% of hydrolysis efficiency was achieved in the LBRs of Set-1, whereas this value was decreased to 20-25% in the LBRs of Set-2<br>which was resulted from OFMSW containing cellulose and less volume of water addition in the Set-2.
The mass of total volatile fatty acids (tVFA) production was found as 7000-9000 mg at the end of 80 days in the LBRs of Set-1, fed with OFMSW without paper, whereas it was 3000 mg at the end of 40 days in the LBR of Set-2, containing only OFMSW with paper. It was also observed that cow manure addition increased the amount of tVFA production in the LBR of Set-2.
In conclusion, LBRs were found as alternative reactors for the degradation of OFMSW compared to completely stirred tank reactors (CSTRs) in terms of rapid hydrolysis and acidification, which can result in high hydrolysis yield and tVFA production.
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Rendall, Charles. "Total energy pseudopotential studies." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321530.
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Kemp, Christopher Gary. "Total solid-phase sysnthesis of the mixrins : antitumour cyclic lipopeptides." Thesis, University College London (University of London), 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540430.
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Boff, Jeffrey M. "Study of volatile compound formation in oxidized lipids and volatile compound retention in processed orange juice." The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1054660479.
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Henry, Dara Jude. "Studies towards the total synthesis of (-)mitragynine using solid-supported reagents." Thesis, University of Cambridge, 2004. https://www.repository.cam.ac.uk/handle/1810/284029.
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Chapter one introduces the natural product mitragynine, illustrating its historical and present day use, and describing the biological properties that have aroused interest in this molecule. Chapter two introduces the natural product mitragynine, illustrating its historical and present day use, and describing the biological properties that have aroused interest in this molecule. Chapter three presents an overview of the previous total synthesis of mitragynine. Chapter four describes the results and discussion studies toward the synthesis of mitragynine using solid-supported reagents. Chapter five provides a formal report of the experimental procedures for chapter four.
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Muro, Maria L. "Platinum (II) terpyridyls excited state engineering and solid-state vapochromic/vapoluminescent materials /." Bowling Green, Ohio : Bowling Green State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=bgsu1242057662.
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Ojala, Marja. "Novel membrane inlet mass spectrometric methods for analysis of organic compounds in aqueous and solid samples /." Espoo [Finland] : Technical Research Centre of Finland, 2001. http://www.vtt.fi/inf/pdf/publications/2001/P451.pdf.
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Davidson, Colin Alexander Bennett. "A biotechnological approach to the total utilisation of crustacean shell waste." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342031.
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Philp, R. N. "The theory of exiton polaritons in thin-film systems and their detection by attenuated-total-reflection spectroscopy." Thesis, University of Essex, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234169.
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Dogan, Eylem. "Two-phase Anaerobic Digestion Of Semi-solid Organic Wastes." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609280/index.pdf.
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The objective of this study is to illustrate that phase separation improves the efficiency of an anaerobic system which digests semi-solid organic wastes. Organic fraction of municipal solid waste (OFMSW) was the semi-solid organic waste investigated. In the first part of the study, the optimum operational conditions for acidified reactor were determined by considering the volatile solid (VS) reductions and average acidification percentages at the end of two experimental sets conducted. Organic loading rate (OLR) of 15 g VS/L.day, pH value of 5.5 and hydraulic retention time (HRT) of 2 days were determined to be the optimum operational conditions for the acidification step. Maximum total volatile fatty acid and average acidification percentage were determined as 12405 mg as HAc/L and 28%, respectively in the reactor operated at optimum conditions. In the second part, an acidification reactor was operated at the optimum conditions determined in the first part. The effluents taken from this reactor as well as the waste stock used to feed this reactor were used as substrate in the biochemical methane potential (BMP) test. The results of BMP test revealed that the reactors fed by acidified samples indicated higher total chemical oxygen demand (tCOD) removals (39%), VS reductions (67%) and cumulative gas productions (265 mL).
The result of this study indicated that the separation of the reactors could lead efficiency enhancement in the systems providing that effective control was achieved on acidified reactors.
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Wang, Mingyang. "Improving Performance And Reliability Of Flash Memory Based Solid State Storage Systems." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1470757497.
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Andersson, Fräs Annika T. "Determination of volatile sulfur compunds in air and other gas matrices : development and applications of solid-phase microextraction /." Linköping : Univ, 2003. http://www.bibl.liu.se/liupubl/disp/disp2003/arts275s.pdf.
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Frederiksen, Mathias Ugelstad. "Novel cyclorelease strategy in the solution and solid phase total syntthesis of 156256 alpha and beta." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397032.
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Gaeta-Bernardi, Andre. "Organic municipal solid waste (MSW) as feedstock for biodiesel production: a financial feasibility analysis." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/86/86131/tde-18062014-100543/.
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The pursuit towards an alternative solution to fossil fuel has facilitated science investigation initiatives that compare various options leading to biodiesel production. Besides conventional feedstock derived from vegetable oils, alternative sources that could be produced in large scale at competitive costs are the main scope of research in this field. This dissertation investigates the financial feasibility using organic solid waste as a feedstock, which results in the production of biodiesel through the conversion of volatile fatty acids (VFA) into lipids. As a result, based on existing references of: (i) capital and operating costs; (ii) internal rate of return; (iii) production and extraction yields for volatile fatty acids and lipids, we concluded that biodiesel production is competitive compared to subsidized biodiesel traded in regions of Europe and the United States. The sensitivity analysis took into consideration independent variables associated with: (i) investments in the plant; (ii) selling price of the biodiesel; (iii) costs of feedstock; and (iv) production yield. The results of such analysis showed the feasibility of using organic solid waste as a feedstock in 86.4% of the total 10,000 simulations, at the required internal rate of return. These results encourage research aims to examine this technology at a larger scale. The adoption of public policies for the urban wastes disposal and collection is also important for the implementation of such technologies.<br>A busca por soluções alternativas aos combustíveis fósseis tem impulsionado as iniciativas de pesquisa científica que comparam várias opções para a produção de biodiesel. Além das tradicionais fontes de matéria-prima provenientes de óleos vegetais, fontes alternativas, que possam ser produzidas em grande escala a custo competitivo, figuram como o principal escopo nesse campo de pesquisa. Essa dissertação investiga a viabilidade financeira da utilização de resíduo sólido orgânico como matéria-prima para a produção de biodiesel, através da conversão de ácidos graxos voláteis em lipídios. Como resultado, baseando-se em dados sobre: (i) investimentos e custos de operação; (ii) taxa interna de retorno requerida; (iii) taxas de extração e produção de ácidos graxos voláteis e de lipídios, conclui-se que a produção de biodiesel é competitiva quando comparada ao biodiesel subsidiado, que é negociado em regiões dos Estados Unidos e da Europa. A análise de sensibilidade realizada levou em consideração variáveis independentes tais como: (i) investimentos na planta; (ii) preço de venda do biodiesel, (iii) custos da matéria-prima e (iv) produtividade. O resultado de tal análise mostrou a viabilidade da utilização de ácidos graxos voláteis para a produção de biodiesel em 86,4% das 10.000 simulações, assumindo a taxa interna de retorno requerida. Esses resultados encorajam pesquisas adicionais para teste da tecnologia em maior escala. A adoção de políticas públicas para o descarte e coleta adequados dos resíduos sólidos urbanos também é importante para o desenvolvimento dessa tecnologia.
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Bryant, Chet Kaiser. "Chemical vapor identification using field-based attenuated total reflectance Fourier transform infrared detection and solid phase microextraction /." Download the dissertation in PDF, 2005. http://www.lrc.usuhs.mil/dissertations/pdf/Bryant2005.pdf.
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Gondran, Amy Christine. "Vegetative Potential to Reduce Total Dissolved Solid Nutrient Ions Generated from Reclaimed Mine Lands in Central Appalachia." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/72873.
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One of the major issues in surface coal mine land reclamation is the impact of total dissolved solids (TDS) on water quality. To address this issue, this study assessed whether vegetation could reduce TDS nutrient ion movement from the rooting zone in early reclamation stages when TDS generation is often highest. Vegetated and un-vegetated paired plots were established across eight sites with gradients in age, spoil material, and vegetative productivity. Ion exchange resin lysimeters were used to compare nutrient ion fluxes in soil solution that contribute to TDS between paired plots. Soil and vegetation properties (used as proxies for evapotranspiration and plant uptake) were characterized at each site and correlated with log ratios of common TDS contributing ions [i.e., base cations Ca2+, Mg2+, Na+, K+ (RBC), sulfate (RSO42-), and total Ca2+, Mg2+, Na+, K+, SO42- (Rtotal)] between un-vegetated and vegetated plots. Strong Spearman correlations were found between RTotal, RBC, and RSO42- during the peak growing season, and were weakened overall during vegetative dormancy. Soil organic matter was shown to be a strong correlate through dormant periods. Correlations between TDS nutrient ions and vegetation suggest evapotranspiration in the growing season, and interception during dormant periods, exert an influence on nutrient ion fluxes. These findings indicate that aggrading forests may reduce TDS nutrient ion loading, through solute retention mechanisms driven by organic matter inputs and plant uptake.<br>Master of Science
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Mader, Brian T. "Gas/solid and gas/particle partitioning of polychlorinated dibenzodioxins, polychlorinated dibenzofurans and polycyclic aromatic hydrocarbons to filter surfaces and ambient atmospheric particulate material /." Full text open access at:, 2000. http://content.ohsu.edu/u?/etd,193.
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Jung, Da-Mi. "Interactions between volatile flavor compounds and food matrix components studied using nuclear magnetic resonance spectroscopic and solid phase microextraction techniques /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
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Akindele, Akinwumi. "The Effects of Ammonia on Anaerobic Digestion of the Organic Fraction of Municipal Solid Wastes." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34568.
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The effect of ammonia on anaerobic digestion of the organic fraction of municipal solid wastes (OFMSW) was investigated in this study. This study involved two sets of experiments. First set involved the investigation of ammonia toxicity on AD of synthetic OFMSW only (SW), at three different phases and pH 7.5, 8.0 and 8.5.
Phase 1 was the Batch Methane Potential (BMP) phase. BMP tests were conducted under ammonia concentration of 2500 mg/L, 5000 mg/L, 7500 mg/L and 10,000 mg/L and at pH 7.5, 8.0, and 8.5, using 500 mL Kimax® glass bottles. The total working volume of the mixture was 300 mL comprising 120 mL of mesophilic anaerobically digested inoculums, 30 g of OFMSW, various TAN concentrations ranging from 2,500, 5,000, 7,500 to 10,000 mg/L, and equal portions of buffer in form of NaHCO3 and KHCO3.
The second phase of the experiment examined whether the tolerance of the bacteria to high ammonia concentration would improve by acclimating the microbes to high ammonia concentrations, through gradual TAN loading. TAN concentration was increased gradually at pH 7.5, 8.0 and 8.5 weekly.
The third phase of the experiment was Semi-continuous batch phase. This phase examined the possibility of reducing the inhibitory effect of ammonia on AD, batch reactors at pH values of 8.0 and 8.5 containing initial TAN concentrations of 7500 mg/L and 10,000 mg/L. 3 g of the digestate containing high ammonia concentration(s) was replaced with fresh substrate at every 4 days, 7 days and 15 days.
The second set of experiment involved study of the effects of ammonia on anaerobic digestion of OFMSW with real landfill leachate (SW+L).
Phase 1 was BMP in which the effect of ammonia was examined at TAN concentrations of 7,500 and 10,000 mg/L.
The phase 2 of the (SW+L) gradual TAN TAN loading. The possibility of adapting mesophilic bacteria to high ammonia concentration was examined.
The results of the study confirmed that ammonia is toxic to AD, at high concentrations. Biogas production reduced with increase in TAN concentration. Reduction in Cumulative Biogas Production (CBP) compared with control reactors was as much as 43 %, 64 % and 77 % in reactors containing 7500 mg/L TAN at pH 7.5, pH 8.0 and pH 8.5. CBP reduced to 80-85 % in reactors containing 10,000 mg/L TAN across the pH examined. Also, replacing 3g of digestate containing high TAN concentrations of 7500 mg/L and 10,000 mg/L with 3 g fresh substrate improved the activity of the mesophilic bacteria as seen in the surges in biogas production when fresh substrate was injected into the reactors.
Similar results were obtained on effect of ammonia on AD of OFMSW mixed with real landfill leachate to simulate an anaerobic bioreactor landfill. CBP reduced as the TAN concentration increased. Compared with control reactors, reactors containing 7500 mg/L TAN at pH 8.0 and pH 8.5 had 61 % and 80 % reduction in CBP. Likewise, reactors containing 10,000 mg/L TAN at pH 8.0 and pH 8.5 had 68 % and 85 % reduction in CBP, compared with control reactors.
Study confirmed that pH influenced the toxicity and composition of Total Ammonia Nitrogen (TAN). At high pH (i.e. 8.5), FAN component of TAN was about 26 % and was inhibitory to the methanogens. Results also showed that mesophilic bacteria could be adapted to a TAN concentration of about 5000 mg/L at pH 7.5 through gradual TAN loading.
Similar results were obtained on effect of ammonia on AD of OFMSW mixed with real landfill leachate to simulate an anaerobic bioreactor landfill. CBP reduced as the TAN concentration increased. Compared with control reactors, reactors containing 7500 mg/L TAN at pH 8.0 and pH 8.5 had 61 % and 80 % reduction in CBP. Likewise, reactors containing 10,000 mg/L TAN at pH 8.0 and pH 8.5 had 68 % and 85 % reduction in CBP, compared with control reactors.
Study confirmed that pH influenced the toxicity and composition of Total Ammonia Nitrogen (TAN). At high pH (i.e. 8.5), FAN component of TAN was about 26 % and was inhibitory to the methanogens. Results also showed that mesophilic bacteria could be adapted to a TAN concentration of about 5000 mg/L at pH 7.5 through gradual TAN loading.
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Schorghofer, Norbert, Shane Byrne, Margaret E. Landis, et al. "The Putative Cerean Exosphere." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/626261.
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The ice-rich crust of dwarf planet 1 Ceres is the source of a tenuous water exosphere, and the behavior of this putative exosphere is investigated with model calculations. Outgassing water molecules seasonally condense around the winter pole in an optically thin layer. This seasonal cap reaches an estimated mass of at least 2 x 10(3) kg, and the aphelion summer pole may even retain water throughout summer. If this reservoir is suddenly released by a solar energetic particle event, it would form a denser transient water exosphere. Our model calculations also explore species other than H2O. Light exospheric species escape rapidly from Ceres due to its low gravity, and hence their exospheres dissipate soon after their respective source has faded. For example, the theoretical turn-over time in a water exosphere is only 7 hr. A significant fraction of CO2 and SO2 molecules can get trapped and stored in perennially shadowed regions at the current spin axis orientation, but not at the higher spin axis tilt, leaving H2O as the only common volatile expected to accumulate in polar cold traps over long timescales. The D/H fractionation during migration to the cold traps is only about 10%.
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Greto, Giorgio. "JST-SPH : a total Lagrangian, stabilised meshless methodology for mixed systems of conservation laws in nonlinear solid dynamics." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/118771/.
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The combination of linear finite elements space discretisation with Newmark family time-integration schemes has been established as the de-facto standard for numerical analysis of fast solid dynamics. However, this set-up suffers from a series of drawbacks: mesh entanglements and elemental distortion may compromise results of high strain simulations; numerical issues, such as locking and spurious pressure oscillations, are likely to manifest; and stresses usually reach a reduced order of accuracy than velocities. Meshless methods are a relatively new family of discretisation techniques that may offer a solution to problems of excessive distortion experienced by linear finite elements. Amongst these new methodologies, smooth particles hydrodynamics (SPH) is the simplest in concept and the most straightforward to numerically implement. Yet, this simplicity is marred by some shortcomings, namely (i) inconsistencies of the SPH approximation at or near the boundaries of the domain; (ii) spurious hourglass-like modes caused by the rank deficiency associated with nodal integration, and (iii) instabilities arising when sustained internal stresses are predominantly tensile. To deal with the aforementioned SPH-related issues, the following remedies are hereby adopted, respectively: (i) corrections to the kernel functions that are fundamental to SPH interpolation, improving consistency at and near boundaries; (ii) a polyconvex mixed-type system based on a new set of unknown variables (p, F, H and J) is used in place of the displacementbased equation of motion; in this manner, stabilisation techniques from computational fluid dynamics become available; (iii) the analysis is set in a total Lagrangian reference framework. Assuming polyconvex variables as the main unknowns of the set of first order conservation laws helps to establish the existence and uniqueness of analytical solutions. This is a key reassurance for a robust numerical implementation of simulations. The resulting system of hyperbolic first order conservation laws presents analogies to the Euler equations in fluid dynamics. This allows the use of a well-proven stabilisation technique in computational fluid dynamics, the Jameson Schmidt Turkel (JST) algorithm. JST is very effective in damping numerical oscillations, and in capturing discontinuities in the solution that would otherwise be impossible to represent. Finally, we note that the JST-SPH scheme so defined is employed in a battery of numerical tests, selected to check its accuracy, robustness, momentum preservation capabilities, and its viability for solving larger scale, industry-related problems.
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Kusano, Maiko. "Comparison of Medical and Forensic Profiling Potential of Volatile Biomarkers from Different Biological Specimens from Individuals and Across Populations." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/307.
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There is limited scientific knowledge on the composition of human odor from different biological specimens and the effect that physiological and psychological health conditions could have on them. There is currently no direct comparison of the volatile organic compounds (VOCs) emanating from different biological specimens collected from healthy individuals as well as individuals with certain diagnosed medical conditions. Therefore the question of matching VOCs present in human odor across various biological samples and across health statuses remains unanswered. The main purpose of this study was to use analytical instrumental methods to compare the VOCs from different biological specimens from the same individual and to compare the populations evaluated in this project. The goals of this study were to utilize headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC/MS) to evaluate its potential for profiling VOCs from specimens collected using standard forensic and medical methods over three different populations: healthy group with no diagnosed medical or psychological condition, one group with diagnosed type 2 diabetes, and one group with diagnosed major depressive disorder. The pre-treatment methods of collection materials developed for the study allowed for the removal of targeted VOCs from the sampling kits prior to sampling, extraction and analysis. Optimized SPME-GC/MS conditions has been demonstrated to be capable of sampling, identifying and differentiating the VOCs present in the five biological specimens collected from different subjects and yielded excellent detection limits for the VOCs from buccal swab, breath, blood, and urine with average limits of detection of 8.3 ng. Visual, Spearman rank correlation, and PCA comparisons of the most abundant and frequent VOCs from each specimen demonstrated that each specimen has characteristic VOCs that allow them to be differentiated for both healthy and diseased individuals. Preliminary comparisons of VOC profiles of healthy individuals, patients with type 2 diabetes, and patients with major depressive disorder revealed compounds that could be used as potential biomarkers to differentiate between healthy and diseased individuals. Finally, a human biological specimen compound database has been created compiling the volatile compounds present in the emanations of human hand odor, oral fluids, breath, blood, and urine.
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Reséndiz, Marino. "Photochemical decarbonylation of ketones in the solid state and in solution ; Progress towards the total synthesis of natural products." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1790313711&sid=16&Fmt=2&clientId=48051&RQT=309&VName=PQD.
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González, Martínez María. "Woody and agricultural biomass torrefaction : experimental study and modelling of solid conversion and volatile species release based on biomass extracted macromolecular components." Thesis, Toulouse, INPT, 2018. http://oatao.univ-toulouse.fr/24326/1/gonzalez_martinez.pdf.
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Nowadays, there is an increasing awareness on the importance of biomass waste as a renewable source of energy, materials and chemicals. In this context, the European project MOBILE FLIP aims at developing and demonstrating mobile conversion processes suitable with variousunderexploited agro- and forest based biomass resources in order to produce energy carriers, materials and chemicals. One of these processes is torrefaction, which consists in a mild thermal treatment, occurring typically between 200 and 300°C during a few tens of minutes in a defaultoxygen atmosphere. The solid product obtained has thermal and processing properties closer to coal, and thus is suitable as fuel for combustion or gasification. During torrefaction, condensable coproducts are released, that may also be source of “green” chemicals. It is therefore crucial to characterize them to optimize the torrefaction process and design industrial units. Up to now, only few works have been focused on characterizing and modelling both solid and condensable species during torrefaction versus operating conditions and feedstock type. Furthermore, these studies typically include a reduced number of biomasses. Cellulose, hemicellulose and lignin,which constitute biomass macromolecular composition, are determining properties to predict biomass behaviour during torrefaction. However, torrefaction tests on these constituents are rare and always based on commercial compounds, which were proved as little representative of the native biomass. The objective of this study is to analyse the influence of biomass characteristics, mainly represented by the macromolecular composition in cellulose, hemicellulose and lignin, on the global behaviour of biomass in torrefaction, both in terms of solid mass loss and of productionprofiles of the volatile species released, in function of the operating conditions.14 biomasses from the main biomass families (deciduouswood, coniferous wood, agricultural byproductsand herbaceous crops) were selected for this study. An optimized extraction procedure was proposed to recover cellulose, hemicellulose and lignin fractions from 5 reference biomasses. Experiments were performed on a thermogravimetric analyzer coupled to a gas chromatography mass spectrometer device through a heated storage loop system (TGA-GC/MS). Solid degradation kinetics and volatile release profiles were followed during torrefaction experiments combining non-isothermal (200 to 300°C at 3°C/min) and isothermal (300°C, 30 min) conditions, ensuring the chemical regime thanks to the appropriate operating conditions. The results obtained with the raw materials demonstrated that biomass macromolecular composition is a main factor influencing biomass behavior in torrefaction. Consequently, the heterogeneity of the resource results in a diverse behavior in torrefaction, particularly in the case of agricultural biomasses. The results with the extracted components evidenced their very different behavior compared to thecommercial compounds, particularly in the case of cellulose. This suggests that a limitation could be induced by the common use in literature of commercial components for torrefaction modelling. The impact on the characterization of macromolecular components was also shown to be prevailing in their behavior in torrefaction, especially in the case of hemicellulose sugar composition and cellulose crystallinity. Furthermore, differences in release kinetics of volatile species during torrefaction were observed, even for volatiles belonging to the same chemical family (acids, furans, ketones). Derived from these results, a torrefaction model based on the additive contribution of extracted cellulose, hemicelluloses and lignin to the global behavior of biomass in torrefaction was proposed, and this for the 5 representative biomasses.
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Aisenbrey, Christopher. "Investigation of the topology of membrane polypeptides by solid state NMR spectroscopy and attenuated total reflection infrared spectroscopy (ATR-FTIR)." Université Louis Pasteur (Strasbourg) (1971-2008), 2003. http://www.theses.fr/2003STR13188.
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Cette thèse est divisée en trois parties qui suivent des approches différentes. Dans la première partie, l'hydrophobicité d'acides amines, propriété bien connue, est déterminée. Un modèle thermodynamique détaillé de la topologie de polypeptides dérivés du LAH4 en fonction du pH a été développé. Ces modifications dans la topologie ont été mises en évidence par la technique de spectroscopie infrarouge de réflexion totale atténuée. (abrégée en anglais ATR-FTIR). Grâce à ces résultats et à un modèle théoretique, nous avons pu déterminer l'enthalpie nécessaire à l'insertion d'acides aminés de la phase aqueuse vers l'intérieur d'une bicouche lipidique. La seconde partie donne une vue d'ensemble (avantages et limites) de l'utilisation de RMN du deutérium sur la 2H3C-alanine. Il est en effet prouvé que cette méthode peut fournir des informations sur la structure et la dynamique des polypeptides membranaires. Bien que la RMN du deutérium ait déjà été utilisée auparavant sur des peptides marqués à l'aide de 2H3C-alanine, l'étude systematique de tels peptides par cette technique éclaire de nouveaux aspects du sujet. Dans la troisième partie, la RMN à l'état solide est appliquée à différents polypeptides et protéines d'origine naturelle. Ainsi, pour la bacteriorhodopsine et la gramicidine A, certains détails de la structure déjà connue du protéine / polypeptide ont été néanmoins élucidés. La structure du ß-peptide amyloide dans sa forme membranaire est quant à elle largement inconnue : nous avons essayé de savoir si la RMN du solide pouvait fournir de plus amples informations. Enfin, pour les protéines colicine E1 et BCL-XL , nous avons testé la validité de modèles disponibles dans la littérature. Dans le cas du domaine formant le canal de la colicine E1, une protéine marquée uniquement à une seule position a été utilisée : les spectres 15N RMN à l'état solide sont parmi les premier mesurés pour une protéine exprimée par bactérie et marquée sur une seule position<br>The thesis consists of three different sections, which follow slightly different approaches. In the first part the hydrophobicity a very basic property, of amino acids is determined. For the series of LAH4-like polypeptides a detailed thermodynamic model for the pH dependent topology of the peptides was developed. The topological changes were measured by attenuated total reflection infrared spectroscopy (ATR-FTIR). The results of the measurements and the theoretical model were used to determine the enthalpy for the insertion of some amino acid from water phase into the lipid bilayer interior. The second part gives a detailed overview of the advantages and problems of the application of deuterium NMR using 2H3C-Alanine. It is shown that the method can give valuable information of structure and dynamics of membrane polypeptides. Even thought solid-state NMR on 2H3C-Alanine labelled peptides was used before the systematic investigation of the properties of deuterium NMR on 2H3C-Alanine labelled peptides gives new and important aspects into the topic. In the third part the solid-state NMR method is applied to different natural polypeptides and proteins. For bacteriorhodopsin and gramicidine A solid-state NMR was used to investigate some details of the known structure of the protein/polypeptide. The structure of the membrane associated form of the amyloid b-peptide is widely unknown. It was tested, if solid-state NMR can provide further information of the membrane associated form of the amyloid b-peptide. For the proteins colicin E1 and BCL-XL detailed models are published and the solid-state NMR experiments are used to test these models. For the measurement of the channel-forming domain of colicin E1 a single-side labelled protein was used. The measured spectra belong to the first 15N solid-state NMR spectra of a single-side labelled protein (expressed in bacteria)
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Sharma, Sabita. "Life Cycle Assessment of Municipal Solid Waste Management regarding Green House Gas Emission: A Case Study of Östersund Municipality, Sweden." Thesis, Mittuniversitetet, Institutionen för teknik och hållbar utveckling, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-17409.
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This study aims to undertake a comprehensive analysis of different waste management systems for the wastes produced in Östersund municipality of Sweden with an impact assessment limited to greenhouse gas emissions and their total environmental effects in terms of global warming potential, acidification potential, and eutrophication potential. A life cycle assessment methodology is used by integrating knowledge from waste collection, transportation, waste management processes and the product utilization. The analytical framework included the definition of functional unit, system boundaries, complimentary system design, waste management, and partial use of the energy. Three different municipal solid waste management scenarios, incineration, composting, and digestion were considered for the study. All wastes from Östersund municipality were classified into biodegradable and combustible and thereafter treated for energy and compost production. Greenhouse gas emissions and total environmental impacts were quantified and evaluated their corresponding benefits compared to three different types of marginal energy production system. The results showed that the major greenhouse gas carbon dioxide and nitrous oxide emissions are greater in composting scenario, whereas methane emission is greater in digestion scenario. Composting scenario that uses additional coal fuel has greater global warming potential and acidification potential compared to other scenarios. Composting scenario using wood fuel additional energy has greater eutrophication potential. The highest reduction in global warming potential is achieved when digestion scenario replace coal energy. The greater reduction in acidification and eutrophication potential achieved when digestion scenario replaced coal energy, and wood fuel respectively. Based on the assumptions made, digestion scenario appears to be the best option to manage solid waste of Östersund municipality if the municipality goal is to reduce total environmental impact. Although there may have plentiful of uncertainties, digestion and incineration scenario results are competitive in reducing environmental effects, and based on the assumptions and factors used for the analysis, the results and conclusions from this study appear to be strong. Key words: Solid waste, incineration, composting, digestion, total environmental effect, wood fuel, biogas.
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Rearden, Preshious R. A. "Applications of Solid Phase Microextraction with Ion and Differential Mobility Spectrometry for the Study of Jet Fuels and Organophosphonates." Ohio University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1142627911.
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McDonald, Shannon Scott. "Characterization and optimization of a high surface area-solid phase microextraction sampler for the collection of trace level volatile organic compounds in the field /." Download the thesis in PDF, 2006. http://www.lrc.usuhs.mil/dissertations/pdf/McDonald2006.pdf.
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Pusvaškienė, Edita. "Development, investigation and application of new microextraction systems for determination of volatile aromatic hydrocarbons." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110222_154322-34086.
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A new solid phase microextraction system composed of nanotubes coating fixed on a stainless steel support is suggested. Thermal stability and selectivity of the system was examined. It was determined that the system can be used for direct and headspace extraction of volatile aromatic hydrocarbons.
Possibilities of four liquid phase microextraction techniques – hollow fibre liquid phase microextraction, liquid phase microextraction based on the solidification of a floating drop, dispersive liquid-liquid microextraction and dispersion-solidification liquid-liquid microextraction – for the extraction of volatile aromatic hydrocarbons were investigated.
Extraction conditions of the investigated methods were optimized and the main analytical characteristics were determined. For all the methods detection limits and repeatability of the results are close. An exception is dispersive liquid-liquid microextraction with slightly higher detection limits. An extraction is especially fast using dispersive liquid-liquid microextraction and dispersion-solidification liquid-liquid microextraction. The most time-consuming method is liquid phase microextraction based on the solidification of a floating drop. All the methods are suitable for clean sample extraction. For the extraction from complex matrices the most suitable methods are headspace solid phase microextraction and hollow fibre liquid phase microextraction.
The prepared microextraction techniques were applied for water and snow... [to full text]<br>Pasiūlyta nauja kietafazės mikroekstrakcijos sistema, kurioje nerūdijančio plieno strypelis dengtas anglies nanovamzdeliais, ištirtas jos terminis stabilumas ir atrankumas, nustatyta, kad sistema tinka lakių aromatinių angliavandenilių ekstrakcijai iš tirpalo ir iš viršerdvės. Ištirtos keturių skysčių-skysčių mikroekstrakcijos metodų - skysčių-skysčių mikroekstrakcijos kapiliare, mikroekstrakcijos užšaldomu tirpiklio lašu, dispersinės skysčių-skysčių mikroekstrakcijos ir dispersinės skysčių-skysčių mikroekstrakcijos užšaldant ekstraktą - galimybės ekstrahuoti lakius aromatinius angliavandenilius. Optimizuotos tirtų metodų ekstrakcijos sąlygos, nustatytos pagrindinės analizinės charakteristikos. Visų metodų rezultatų pasikartojamumas ir aptikimo ribos artimi. Išimtis – dispersinė skysčių-skysčių mikroekstrakcija, kuria gautos kiek didesnės aptikimo ribos. Greičiausi ekstrakcijos metodai - dispersinė skysčių-skysčių mikroekstrakcija ir dispersinė skysčių-skysčių mikroekstrakcija užšaldant ekstraktą, ilgiausiai trunka mikroekstrakcija užšaldomu tirpiklio lašu. Švarių mėginių ekstrakcijai tinka visi tirti metodai, užterštiems mėginiams geriau tinka kietafazė mikroekstrakcija iš viršerdvės arba skysčių-skysčių mikroekstrakcija kapiliare. Paruoštos lakių aromatinių angliavandenilių mikroekstrakcijos metodikos pritaikytos vandens ir sniego mėginių analizei.
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VENKATA, PADMA PRIYA. "Computational Modeling of Heat and Mass Transfer in Planar SOFC: Effects of Volatile Species/Oxidant Mass Flow Rate and Electrochemical Reaction Rate." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1205169104.
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Mahadevan, Muralidharan Ananth. "Analysis of Garbage Collector Algorithms in Non-Volatile Memory Devices." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1365811711.
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Tang, Bing. "Applications of Solid-Phase Microextraction to Chemical Characterization of Materials Used in Road Construction." Doctoral thesis, Stockholm : Division of Highway Engineering, Royal Institute of Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4637.
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Huertas-Rivera, Adhly M. "Identification of the Active Odors From Illicit Substances for the Development of Optimal Canine Training Aids." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2990.
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The exploitation of illicit substances, such as drugs and explosives, is on the rise. Special attention must therefore be considered to reduce the transportation and storage of these illicit substances by improving the capability of detection, even when hidden from view. Although analytical methods of detection for both drugs and explosives have improved over time, biological detectors, such as canines, are still commonly used. In comparison to humans, these canines have a larger number of olfactory receptors and a greater olfactory epithelium surface area, providing them with a more enhanced olfaction than that of humans.
The premise for the detection of illicit drugs and explosives is based on the premise that these substances though hidden, will emit volatile organic compounds (VOCs). These VOCs are not often the parent drug or explosive, they are essentially a chemical associated with the source and provide a reliable indication of the illicit substance. Previous successful research has been conducted on the identification of the active odors present in the headspace of cocaine, methamphetamine, and MDMA but instead for marijuana and heroin there have been minimum success. Thus, in the present research a method using headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) was optimized to identify the VOCs makeup of heroin and marijuana to further identify the active odor compound(s) responsible for the alert response of biological detectors (canines). A mixture of acetic acid and acetylsalicylic acid was identified as target odor mimic for heroin by certified detector canines, while a mixture of limonene and caryophyllene was recognized as odor mimic for marijuana by conducting ORTs. The training aids developed successfully mimic the scent of the actual illicit substance and can be used to improve the capabilities of both drug and explosive detection canines.
Additionally, as growing threat of improvised explosives has created a worldwide concern and emphasized the requirement of a greater spectra of canine training aids that covers the complete range of explosives available, a new approach for the creation of training aids for IEDs have been evaluated. The use of a dynamic collection system have proved to be an option to develop fast and reliable canine training aids for IEDs.
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Marineau, Jason Joseph. "New Applications of Cyclobutadiene Cycloadditions: Diversity and Target Oriented Synthesis." Thesis, Boston College, 2010. http://hdl.handle.net/2345/1741.
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Thesis advisor: Marc L. Snapper<br>Cyclobutadiene cycloadditions provide rapid access to rigid polycyclic systems with high strain energy and unusual molecular geometries. Further functionalization of these systems allows entry into unexplored chemical space. A tricarbonylcyclobutadiene iron complex on solid support enables exploration of these cycloadditions in a parallel format amenable to diversity oriented synthesis. Modeling of the cycloaddition transition states with density functional calculations provides a theoretical basis for analysis of the regioselectivity observed in generation of these substituted bicyclo[2.2.0]hexene derivatives. The high strain energy accessible in cyclobutadiene cycloadducts and their derivatives renders them useful synthons for access to medium-ring natural products through ring expansion. Torilin, a guaiane sesquiterpene isolated from extracts of the fruits of Torilis japonica, exhibits a range of biological activities including testosterone 5α-reductase inhibition, hKv1.5 channel blocking, hepatoprotective, anti-inflammatory and anti-cancer effects. These activities are reviewed and analyzed from the perspective of a common biochemical target. Tandem oxidation and acid-catalyzed rearrangement of a highly strained tetracyclo[5.3.0.01,5.02,4]decane in the presence of tetrapropylammonium perruthenate provides the bicyclo[5.3.0]decane core of this natural product with complete control of relevant stereochemistry. The complex precursor required for this rearrangement is rapidly accessed by cyclopropanation of an intramolecular cyclobutadiene cycloadduct. Synthetic studies are reported which provide preliminary access to 8-deoxytorilolone<br>Thesis (PhD) — Boston College, 2010<br>Submitted to: Boston College. Graduate School of Arts and Sciences<br>Discipline: Chemistry
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Rintsch, Eileen Tabata. "Effects of a forested state park on stream dissolved organic carbon and total suspended solid concentrations in an agriculturally dominated watershed in SW Ohio." Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1626962623587062.
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Zethelius, Thea. "Development of headspace solid phase microextraction gas chromatography mass spectrometry method for analysis of volatile organic compounds in board samples : Correlation study between chromatographic data and flavor properties." Thesis, Karlstads universitet, Institutionen för ingenjörs- och kemivetenskaper (from 2013), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-84941.
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The purpose of this thesis work was to develop a headspace solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) method to detect volatile organic compounds (VOCs) in board samples and to statistically investigate potential correlation between chromatographic data and flavor data obtained from a trained panel. The developed method would hopefully serve as a complement to the already established routine analyses at Stora Enso and gain an increased understanding of which VOCs in the board influence its flavor properties. The impact of incubation time and adsorption time on the area under curve (AUC) was studied with a Design of Experiment screening using the software MODDE. The screening data showed a correlation between large AUC and low repeatability measured as relative standard deviation (RSD). The data was hard to fit to a model due to the large RSD values for the replicates, AUC for identified compounds as response gave an acceptable fit. The regression coefficients for the model showed that a longer adsorption time gave larger AUC, while incubation time had no significant impact on the response. Instead of following up the screening with an optimization, the focus was shifted to improving the repeatability of the method, i.e. lowering the RSD. The high RSD was believed to mainly be the result of leakage of analytes and unstable temperature during adsorption, preventing the system from reaching equilibrium. Different heating options and capping options for the vial was tested. Septum in crimp cap ensured a gas tight seal for the vial, giving lower RSD values and larger AUC compared to the other alternatives, showing that there was indeed a leakage. Using oil bath ensured stable temperature during the adsorption and detection of a larger number of VOCs but created a temperature gradient in the vial due to it not being fully submerged in the oil. Oil bath gave larger AUC, but still high RSD due to the temperature gradient making the method sensitive to variance in fiber depth in the vial. The final method was performed with 2 g of board sample in a 20 ml headspace vial sealed with a crimp cap with septa. The incubation and adsorption were performed with the vial immersed in a 90-degree oil bath. 20 min incubation time was chosen based on the time it took to get a stable temperature gradient in the vial, and 20 minutes adsorption time was chosen as a good compromise between large AUC and low RSD. Compared to Stora Ensos routine analysis, the developed SPME method gave chromatograms with an improved signal-to-noise ratio for the base line and several more peaks with larger AUC. For the board sample used during method development, the SPME-method identified 34 VOCs, while the routine analysis only identified 12. The developed method was applied on 11 archived board samples of the same quality that were selected based on their original flavor properties, to get a large diversity of samples. Flavor analysis was performed by letting a trained flavor panel describe the flavor based on intensity and character of the water that had individually been in indirect contact with one of the 11 board sample for 24 h. Potential correlation between chromatographic data obtained with the developed method and the flavor experience described by the flavor panelists was statistically investigated with the multivariate analysis software SIMCA. The correlation study showed that a combination of 12 VOCs with short retention time are most likely the main source of off-flavor which of 5 could only be identified with the developed SPME method. VOCs with long retention time did not contribute to an off-flavor and might have a masking effect on flavor given by other VOCS, however not confirmed in this study. Furthermore, the age of the board samples proved to be a good indicator for prediction of the flavor intensity, whereas the total AUC of the samples was not. Possible correlation between detected VOCs in the samples and flavor character given by the flavor panel were seen, however the variation in the data and the sample set were too small, preventing from making conclusions on individual VOCs impact on the flavor experience. The developed HS-SPME-GC-MS method would serve as a complement to the already established routine analyses at Stora Enso and has slightly increased the understanding of which VOCs in the board influence the flavor properties
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Yu, Ruixuan Ryan. "Hybrid-Phase Native Chemical Ligation Approaches to Overcome the Limitations of Protein Total Synthesis." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1469191712.
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Paula, Daniela Mendes Louzada de. "Análise toxicológica de antidepressivos em sangue total por cromatografia em fase gasosa com detector de nitrogênio e fósforo." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/9/9141/tde-10042007-150259/.
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Um método cromatográfico foi desenvolvido para determinação dos antidepressivos mais prescritos no Brasil e seus produtos de biotransfomação (amitriptilina, imipramina, clomipramina, desmetilclomipramina, desipramina, nortriptilina, fluoxetina, norfluoxetina e sertralina) em sangue total por cromatografia em fase gasosa com detector de nitrogênio e fósforo. A extração em fase sólida (EFS) com o cartucho abselutTM NEXUS foi empregada de forma inovadora. O procedimento de extração consistiu na diluição de 0,5mL de sangue total em tampão (pH 9,5), aplicação da amostra no cartucho, remoção de interferentes usando tampão (pH 9,5) e eluição dos analitos com diclorometano/ isopropanol (17/3 v/v); a etidocaína foi adotada como padrão interno. Os limites de detecção (LD) e quantificação (LIQ) encontrados foram de 0,1mg/L a 0,4mg/L e de 0,4mg/L a 1,6mg/L, respectivamente. O método foi preciso, específico e linear na faixa de concentração estudada (do LIQ até 12mg/L). A recuperação média de todos os analitos foi 65,5%. O método foi aplicado em amostras de âmbito forense e de emergência clínica.<br>A gas chromatographic method was developed to determine antidepressants most prescribed in Brazil and their metabolites (amitriptyline, imipramine, clomipramine, desmethylclomipramine, desipramine, nortriptyline, fluoxetine, norfluoxetine, and sertralina) in whole blood, using solid phase extraction and gas chromatography with nitrogen-phosphorus detection. The solid-phase extraction (SPE) with abselutTM NEXUS was applied in an innovative manner. The extraction procedure consists of the dilution of 0.5mL of whole blood in buffer (pH 9.5), application of the sample in the cartridge, washing with buffer (pH 9.5) and elution of the analytes with dichloromethane/isopropanol (17/3, v/v). The limit of detection (LOD) and quantification (LLOQ) were from 0.1mg/L to 0.4mg/L and from 0.4mg/L to 1.6mg/L, respectively. Etidocaine was used as internal standard. The method was precise, specific and linear in the studied concentration (range from LLOQ to 12mg/L). The average recovery of all analytes was 65,5%. Forensic and clinical emergency samples were submitted to the validated method.
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Sanchez, Claudia L. Ms. "Evaluation of the Scent Collection System for Its Effectiveness in Volatile Organic Compound Collection and Use in Canine Training." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/1914.
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As a result of increased terrorist activity around the world, the development of a canine training aid suitable for daily military operations is necessary to provide effective canine explosive detection. Since the use of sniffer dogs has proven to be a reliable resource for the rapid detection of explosive volatiles organic compounds, the present study evaluated the ability of the Human Scent Collection System (HSCS) device for the creation of training aids for plasticized / tagged explosives, nitroglycerin and TNT containing explosives, and smokeless powders for canine training purposes. Through canine field testing, it was demonstrated that volatiles dynamically collected from real explosive material provided a positive canine response showing the effectiveness of the HSCS in creating canine training aids that can be used immediately or up to several weeks (3) after collection under proper storage conditions. These reliable non-hazardous training aids allow its use in areas where real explosive material aids are not practical and/or available.
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Bourbour, Ajdari Elena. "Volatile Organic Compound (VOC) Emission during Cured-in-Place-Pipe (CIPP) Sewer Pipe Rehabilitation." ScholarWorks@UNO, 2016. http://scholarworks.uno.edu/td/2126.
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The maintenance or replacement of deteriorated pipes and culverts is a constant and significant concern for municipalities and transportation agencies in the United States (Donaldson and Wallingford, 2010). Trenchless technologies and especially the Cured-in-place pipe (CIPP) method have become increasingly common ways to preserve infrastructures owing to their feasibility, cost-effectiveness, and fewer social impacts (Jung and Sinha, 2007). Therefore, there is a growing need to understand the direct and indirect effects of pipeline rehabilitation activities on the environment. Nearly all past CIPP studies have focused on its mechanical properties, and its environmental impacts are poorly investigated and documented (Allouche et al. 2012). Sewer pipelines and storm-water culverts are administered by municipalities and transportation agencies who bear the responsibility for rehabilitation and renewal of these infrastructures. In consequence, they rarely allow sampling and research projects in the field due to liability issues. This is a main obstacle to conducting comprehensive, precise, and unbiased research on CIPP environmental impacts and to date, the degree of relevant health effects and related environmental impacts have remained unknown.
Numerous building indoor air contamination incidents indicate that work is needed to understand the magnitude of styrene emission from CIPP sanitary sewer repairs. The main goal of this study was to better comprehend Volatile Organic Compounds emission at three CIPP sanitary sewer installation sites in one U.S. city. Results showed that CIPP chemical emissions may be a health risk to workers and nearby building inhabitants. Additional testing and investigations regarding chemical emissions from CIPP should be commissioned to fill in the environmental and public health knowledge gaps. The acute and chronic chemical exposure risks of CIPP chemical steam constituents and styrene to sensitive populations should be further examined.
Other goals of this study were to estimate the magnitude of solid waste generated as well as the amount of certain criteria air pollutants and greenhouse gases emitted from onsite heavy equipment for both CIPP and open-cut sites in a U.S city. The results indicated that the amount of open-cut related solid waste, criteria air pollutants, and greenhouse gases were greater than those during CIPP activities. Additional work is needed to quantify pollutant emissions from CIPP and open-cut activities and consider emissions from a cradle-to-grave standpoint.
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Salgado, Monique Toledo. "Influência da variação da taxa de recirculação de percolado na digestão anaeróbia da fração orgânica de resíduos sólidos urbanos." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-17112016-120429/.
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A eficiência do processo de digestão anaeróbia dos resíduos sólidos orgânicos pode ser alterada com a recirculação do percolado. Considerado esse aspecto, o presente trabalho teve como objetivo avaliar a taxa da recirculação do percolado na eficiência do processo de digestão anaeróbia da fração orgânica dos resíduos sólidos urbanos. Assim, foram montados reatores de 3,45 litros preenchidos com resíduo padrão (fração orgânica de resíduos sólidos urbanos padrão) e inóculo (percolado). O valor de referência foi o teor de sólidos totais de 13%. Analisou-se o desempenho dos reatores variando taxas de recirculação (10, 30 e 50% em volume de inóculo). Foram realizados análises físico-químicas e exames microscópicos em amostras de percolado para avaliar o desempenho desses reatores. Os resultados dessas análises indicaram inibição da fase metanogênica nos reatores com maiores taxas de recirculação (30 e 50%). O reator com taxa de recirculação de 10%, comparado aos demais reatores, obteve maior eficiência na partida, com elevada produção de metano e maior percentual de degradação de sólidos. Os exames microscópicos realizados em amostras de percolado desse reator revelaram predominância de organismos de morfologia com características de Methanococcus, enquanto nos demais reatores foi observada maioria de organismos com morfologia semelhante a fungos. Concluiu-se que a taxa de recirculação de percolado influi significativamente nos biorreatores degradando a matéria orgânica, e que altas taxas de recirculação podem levar à inibição total do ecossistema existente no reator.<br>The performance of the anaerobic digestion process of organic solid residues can be modified by the leachate recirculation. Considering this aspect, the present paper aims to evaluate the leachate recirculation rate in the eficiency of the anaerobic digestion process of the organic fraction of urban solid residues. Thus, 3,45 liter reactors were constructed and filled with standard waste (standard organic fraction of urban solid residues) and seed (leachate), having the total solid content of 13% as a value of reference. The performance of the reactors was analyzed by varying recirculation taxes (10, 30 and 50% in volume of seed). Leachate samples from these reactors were examined through microscopic and physical-chemical analyses to evaluate theirs performance. The results of these analyses indicated an inhibition of the metanoghenic phase in the reactors with larger rates of recirculation (30 and 50%). The reactor with 10% recirculation rate obtained larger efficiency in the start, methane production and percentage of solid degradation, compared to other reactors. The microscopic examinations in the leachate samples from this reactor presented a predominance of organisms with characteristics Methanococcus morphology, whereas in the others reactors most organisms prsented a similar morphology to fungus. It was possible to conclude that the leachate recirculation rate has a significant influence on the degradaion of the organic material from bioreactors and that high recirculation rates can lead to the total inhibition of the ecosystem existig in the reactor.
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Palma, Aline Schwertner. "Caracterização qualitativa do perfil volátil de vinhos espumantes brasileiros elaborados com um assemblage inovador submetidos a diferentes condições de segunda fermentação." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/129730.
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Os vinhos espumantes elaborados pelo método Tradicional são elaborados, comumente, a partir das uvas Chardonnay, Pinot Noir, Chadonnay, Riesling, Viognier, Trebbiano e Pinot Noir e os componentes voláteis destes espumantes já têm merecido a atenção de diversos estudos científicos. Entretanto, vinhos espumantes produzidos a partir de outros varietais de uvas ainda não foram alvo de pesquisas científicas. A segunda fermentação ocorre dentro da garrafa e acaba por conferir uma maior complexidade aromática ao espumante produzido pelo método Tradicional, devido ao contato do vinho com as leveduras em meio redutor, por um determinado período de tempo. Isto acontece devido aos produtos secundários do metabolismo das leveduras, durante a conversão de açúcares em etanol e dióxido de carbono. Esta conversão depende dos nutrientes adicionados, chamados adjuvantes de fermentação, bem como da espécie de levedura utilizada, visto que cada levedura possui um metabolismo diferente para a utilização dos nutrientes e açúcares presentes no vinho base. Assim, objetivou-se, neste trabalho, caracterizar os componentes voláteis de vinhos espumantes de uma vinícola gaúcha, que emprega um assemblage inovador, empregando uvas Chadonnay, Riesling, Viognier, Trebbiano e Pinot Noir. Do assemblage deste vinho base utilizou-se, para segunda fermentação, duas espécies de leveduras comerciais: Saccharomyces cerevisiae e Saccharomyces bayanus. Para cada levedura utilizada na fermentação do vinho base, oito diferentes adjuvantes de fermentação foram empregados. A determinação dos compostos voláteis se deu através da técnica de microextração em fase sólida no modo headspace (HS-SPME) e cromatografia gasosa acoplada a detector de espectrometria demassa quadrupolar (GC/MS). Ao total, 25 compostos foram tentativamente identificados nos vinhos em estudo, sendo os compostos majoritários citados a seguir, com sua possível contribuição para o aroma destes vinhos: octanoato de etila (aroma de fruta), álcool isoamílico (aroma de banana), ácido octanoico (aroma de pimentão) e álcool feniletílico (aroma floral). O fenetil fenilacetato, um dos compostos minoritários tentativamente identificado em alguns dos vinhos, até então não reportado em vinho espumante, é associado a aroma frutado. Não foi possível distinguir subgrupos entre os 16 vinhos em estudo, provenientes de diferentes condições na segunda fermentação, quando as áreas cromatográficas dos compostos voláteis destes 16 vinhos foram submetidas a análise de cluster. Isto implica em que, nas condições experimentais deste estudo, não foi possível distinguir os voláteis dos vinhos fermentados (2ª fermentação) com S. cereviseae e os fermentados com S. bayanus. A mesma análise de cluster mostrou a subdivisão dos compostos voláteis dos 16 vinhos em dois grupos, os quais se distinguiram, provavelmente, devido aos diferentes adjuvantes nutricionais empregados: fosfato e Thiazote. Desta forma, através de análise qualitativa por HS-SPME-GC/MS, foi possível verificar a homogeneidade do perfil volátil dos 16 vinhos espumantes, obtidos a partir de diferentes adjuvantes de fermentação e duas espécies distintas de leveduras Saccharomyces sp, além de comparar os componentes voláteis presentes nestes espumantes com aqueles reportados na literatura para outros vinhos espumantes.<br>Sparkling wines elaborated by Traditional Method are usually produced by the grapes Chardonnay, Pinot Noir and Riesling, in which the volatile compounds of these sparkling wines have been calling attention to scientific studies. However, sparkling wines produced by other varietal grapes have not been a target of scientific research yet. The second fermentation occurs inside the bottle, in which confer a greater aromatic complexity to the sparkling wine produced by Traditional Method, due to the contact of it with lees in a reducing medium during a certain period of time. This happens due to secondary products of yeast metabolism, during the conversion of sugar in ethanol and carbon dioxide. This conversion depends on the nutrients added, called fermentation adjuvants, as the yeast used, since each one has a different metabolism for using this nutrients and sugars presented in the base wine. Thus, this work aims to characterize the volatile compounds of a south Brazilian winery, which use an innovative assemblage, using the grapes Chardonnay, Riesling, Viognier, Trebbiano and Pinot Noir. To the base wine, two different commercial yeasts were added: Saccharomyces cerevisiae and Saccharomyces bayanus to the performance of second fermentation. To each yeast used for fermenting the base wine, eight different fermentation adjuvants were used. The determination of volatile compounds were performed by Headspace solid-phase Microextraction (HS-SPME) and gas chromatography coupled to a mass quadrupole spectrometry (GC/MS). In total, 25 compounds were tentatively identified in the studied sparkling wines, being the majority listed as it follows, with their possible contribution to these sparkling wines aroma: ethyl octanoate (fruity), isoamyl alcohol (banana), octanoic acid (green pepper), and phenethyl alcohol (flower). Phenethyl phenylacetate, one of the minority compounds tentatively identified in some of the sparkling wines, is associated with fruity aroma. It was not possible to distinguish subgroups from different conditions during the second fermentation, when submitting the chromatographic areas of volatile compounds to cluster analysis. It implies that, under the experimental conditions of these study, it was not possible to differ the volatile compounds of the fermented (2nd fermentation) with S. cerevisiae and those which were fermented with S. bayanus. The same cluster analysis showed a subdivision of volatile compounds of the 16 wines in two groups, in which were probably distinguished due to the different nutritional adjuvants used: phosphate and Thiazote. Thus, throughout qualitative analysis by HS-SPME-GC/MS, it was possible to verify the homogeneity of volatile profile of the 16 sparkling wines, obtained by different fermentation adjuvants and two different yeast species of Saccharomyces sp, besides the comparison of volatile compounds presented in these sparkling wines with those others reported in the literature.
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Pusvaškienė, Edita. "Naujų mikroekstrakcijos sistemų kūrimas, tyrimas ir taikymas lakių aromatinių angliavandenilių nustatymui." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110222_154345-72153.
Full textAbstract:
Pasiūlyta nauja kietafazės mikroekstrakcijos sistema, kurioje nerūdijančio plieno strypelis dengtas anglies nanovamzdeliais, ištirtas jos terminis stabilumas ir atrankumas, nustatyta, kad sistema tinka lakių aromatinių angliavandenilių ekstrakcijai iš tirpalo ir iš viršerdvės. Ištirtos keturių skysčių-skysčių mikroekstrakcijos metodų - skysčių-skysčių mikroekstrakcijos kapiliare, mikroekstrakcijos užšaldomu tirpiklio lašu, dispersinės skysčių-skysčių mikroekstrakcijos ir dispersinės skysčių-skysčių mikroekstrakcijos užšaldant ekstraktą - galimybės ekstrahuoti lakius aromatinius angliavandenilius. Optimizuotos tirtų metodų ekstrakcijos sąlygos, nustatytos pagrindinės analizinės charakteristikos. Visų metodų rezultatų pasikartojamumas ir aptikimo ribos artimi. Išimtis – dispersinė skysčių-skysčių mikroekstrakcija, kuria gautos kiek didesnės aptikimo ribos. Greičiausi ekstrakcijos metodai - dispersinė skysčių-skysčių mikroekstrakcija ir dispersinė skysčių-skysčių mikroekstrakcija užšaldant ekstraktą, ilgiausiai trunka mikroekstrakcija užšaldomu tirpiklio lašu. Švarių mėginių ekstrakcijai tinka visi tirti metodai, užterštiems mėginiams geriau tinka kietafazė mikroekstrakcija iš viršerdvės arba skysčių-skysčių mikroekstrakcija kapiliare. Paruoštos lakių aromatinių angliavandenilių mikroekstrakcijos metodikos pritaikytos vandens ir sniego mėginių analizei.<br>A new solid phase microextraction system composed of nanotubes coating fixed on a stainless steel support is suggested. Thermal stability and selectivity of the system was examined. It was determined that the system can be used for direct and headspace extraction of volatile aromatic hydrocarbons.
Possibilities of four liquid phase microextraction techniques – hollow fibre liquid phase microextraction, liquid phase microextraction based on the solidification of a floating drop, dispersive liquid-liquid microextraction and dispersion-solidification liquid-liquid microextraction – for the extraction of volatile aromatic hydrocarbons were investigated.
Extraction conditions of the investigated methods were optimized and the main analytical characteristics were determined. For all the methods detection limits and repeatability of the results are close. An exception is dispersive liquid-liquid microextraction with slightly higher detection limits. An extraction is especially fast using dispersive liquid-liquid microextraction and dispersion-solidification liquid-liquid microextraction. The most time-consuming method is liquid phase microextraction based on the solidification of a floating drop. All the methods are suitable for clean sample extraction. For the extraction from complex matrices the most suitable methods are headspace solid phase microextraction and hollow fibre liquid phase microextraction.
The prepared microextraction techniques were applied for water and snow... [to full text]
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Liotta, Flavia. "Bio-methanation tests and mathematical modelling to assess the role of moisture content on anaerobic digestion of organic waste." Phd thesis, Université Paris-Est, 2013. http://tel.archives-ouvertes.fr/tel-00967951.
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Dry Anaerobic Digestion (AD) presents different advantages if compared to wet AD, i.e. smaller reactor size, lesser water addition, digestate production and pretreatment needed, although several studies have demonstrated that water promotes substrate hydrolysis and enables the transfer of process intermediates and nutrients to bacterial sites. To better understand the role of water on AD, dry and semidry digestion tests of selected complex organic substrates (food waste, rice straw, carrot waste), with various TS contents of the treated biomass have been carried out in the present study. The results confirm that water plays an essential role on the specific methane production rate, final methane yield and Volatile Solids (VS) degradation. The final methane yield in semi-dry and dry conditions was 51% and 59% lower for rice straw and 4% and 41% lower for food waste, respectively, if compared with wet conditions. Inhibition tests, based on Volatile Fatty Acid (VFA) analysis, were carried out to investigate the specific inhibition processes that take place with the selected substrates at different TS contents. In wet AD of carrot waste no VFA accumulation was found, and all VFA concentrations were lower than the inhibition limits. A direct correlation between TS content and total VFA (TVFA) concentration was noticed for rice straw and food waste AD. For rice straw a maximum TVFA concentration of 2.1 g/kg was found in dry condition, 1 g/kg in semidry conditions and 0.2 g/kg in wet conditions, whereas for food waste the TVFA concentration was 10 g/kg in dry condition, 9 g/kg in semidry conditions and 3 g/kg in wet conditions. A Mathematical model of complex organic substrate AD in dry and semidry conditions has been proposed to simulate the effect of TS content on the process. The data obtained from batch experiments, in terms of methane production and VFA concentrations, were used to calibrate the proposed model. The kinetic parameters of VFA production and degradation, calibrated using the experimental data, resulted highly dependent on the TS content and different from wet AD literature values. This is due to VFA accumulation in dry conditions, which implies higher values of the inhibition factors introduced in the model. Finally, as dry AD takes usually place in Plug Flow (PF) reactors, an historical and critical review on the role of hydrodynamics in PF bioreactors has been carried out
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Milenija, Marković. "Model unapređenja ekološkog statusa zatvorenog sistema vodnih tela akumulacija." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2015. https://www.cris.uns.ac.rs/record.jsf?recordId=95401&source=NDLTD&language=en.
Full textAbstract:
Eksperimentalnim istraživanjem u okviru doktorske teze utvrđen je trend promene fizičko-hemijskih parametara: mutnoća, temperatura, provodljivost i pH vode, koncentracija katjona Cd2+, As3+, Hg2+ i Pb2+, ukupnog azota, fosfora i sulfatnog ajona u vodi i sedimentu, na lokalitetu Zapadne Srbije, slivno područje akumulacije Vrutci u 2003/2014. Rezultati istraživačkih aktivnosti predstavljali su osnovu za razvoj regresionog modela kojim se može predvideti koncentracija katjona teških metala u jezerskoj vodi. Primenom klaster analize, dendograma i PCA analize dobijena su tri faktora na osnovu kojih se posmatra uticaj ključnih fizičko-hemijskih parametara na kvalitet vode zatvorenog vodnog tela akumulacije pri čemu su dobijene visoko korespodentne funkcionalne zavisnosti sa realnim podacima u jezeru. Ovakva istraživanja su po prvi put sprovedena za selektovani lokalitet u Srbiji.<br>Experimental studies in the doctoral thesis established the trend of changes in the physico-chemical parameters: turbidity, temperature, conductivity and pH of the water, the concentration of cations Cd, As, Hg and Pb, total nitrogen, phosphorus and sulphate anion in water and sediment at the site of Western Serbia, the catchment area of the reservoir Vrutci in 2003/2014. Results of research activities constituted the basis for the development of a regression model which can predict the concentration of heavy metal cations in lake water. Cluster analysis, dendograms and PCA (principal component analysis) were resulted by three factors, which could be possible to registre the impact of key physical and chemical parameters on the water quality of the closed lake reservoirs.The obtained results by multivariance analysis has showen the highly correspondent functional dependence with real data in a lake. Such research investigations were for the first time carried out in selected localities in Serbia.
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Sow, Abdellahi. "Étude expérimentale du collage du méthanol et de sa désorption chimique successive à son hydrogénation sur des surfaces d'intérêt astrophysique." Thesis, Cergy-Pontoise, 2019. http://www.theses.fr/2019CERG1020.
Full textAbstract:
L’objectif de cette thèse est de comprendre les processus physiques et chimiques (le collage, désorption chimique) qui se produisent sur les grains de poussière interstellaire. Plus spécifiquement, ma thèse se concentre sur l'étude expérimentale de la désorption chimique et du collage du méthanol sur des surfaces d’intérêt astrophysique.Cette thèse rapporte la mesure expérimentale de la désorption, des COMs à la suite de l'exposition de H sur les manteaux de glace ainsi que l'étude expérimentale du collage du méthanol sur des surfaces d'intérêt astrophysique. L'accent est mis sur les espèces les plus abondantes et les plus connues, tel que le méthanol (CH3OH). On réalise une simulation expérimentale de l'hydrogénation du méthanol déposé sur une surface froide (10-40 K) et on l'analyse par des méthodes spectroscopiques.Toutes les expériences ont été réalisées avec l’expérience VENUS située au laboratoire LERMA à l’université de Cergy Pontoise, France. VENUS est composée d’une chambre à ultra-vide (UHV), appelée chambre principale, dotée d’une pression de base d’environ 10^{-10} mbar. Des atomes/molécules sont dirigées vers un porte-échantillon dans la chambre UHV au moyen d’un système à quatre jets séparés. La température du porte-échantillon peut être contrôlée entre 7 K à 400 K. Les produits sont sondés par spectrométrie de masse et spectroscopie infrarouge par réflexion en adsorption.Nous avons d'abord étudié la profondeur de pénétration des atomes H sur des films réactifs de NO et H_{2}CO. Nous avons démontré que seule la première couche réagissait avec H, et que les processus d'hydrogénation sont dominés par des effets de surface.Nous avons étudié le collage du méthanol en fonction de la température de la surface, de 7 K jusqu'à 40 K, ces températures de surface sont inférieures à sa température de désorption. On a fait varier la composition du substrat (^{13} CO, H_{2} O, et or). Nous avons pu démontrer que la variation de la température de surface à deux tendances antagonistes: textit{i}) Le collage diminue de 30% avec l'augmentation de la température de surface de 7 à environ 16 K.textit{ii}) Le collage augmente progressivement à une température supérieure à 16 K jusqu'à 40 K où il a une valeur similaire à celle de 7 K. Ces profils montrent qu’il existe également une légère différence dans le degré de collage aux températures les plus basses pour les différents substrats. La surface dorée présente le collage le plus faible et le substrat ^{13} CO (2 ML), le plus élevé.Les expériences préalables (Kimmel et al.2001, Bisschop et al.2006) n'ont pas étudié la variation avec la température et une valeur minimale du collage de 0.85 ± 0.05 à 14 K a été établie.La diminution du collage à très basses température est donc inédite et très importante (relativement).Enfin, nous avons montré que sous l'effet de l'exposition à un jet d'atomes H, un film de méthanol subit une diminution.Nous pensons que les réactions d'abstraction: CH3OH + H ------> CH2OH + H2, suivie de la réaction d'addition: CH2OH + H ------> CH3OH sont responsables du retour en phase gazeuse d'une partie du film de méthanol. Cette désorption chimique est plus efficace sur l'or que sur l'eau. Sur une sous couche de ^{13}CO elle est plus rapide que la formation du 13CH3OH, mais reste limité à une fraction de la couche.L'impact de la diminution du collage et de la désorption chimique du méthanol sur le maintient de cette COMs en phase gazeuse dans les nuages moléculaires reste à étudier mais les deux aspects vont dans le sens d'un maintient plus efficace qu' initialement estimé<br>The goal of this thesis is to understand the physical and chemical processes (sticking, chemical desorption) that occur on interstellar dust grains. More specifically, my thesis focuses on the experimental study of chemical desorption and methanol sticking on surfaces of astrophysical interest.This thesis reports the experimental measurement of desorption of COMs following exposure to H on ice mantles and the experimental study of methanol sticking on surfaces of astrophysical interest. The focus is on one of the most abundant and well-known species, that is methanol (CH3OH).An experimental simulation of the hydrogenation of methanol deposited on a cold surface (10-40 K) is carried out and analyzed by spectroscopic methods.All experiments were carried out with the VENUS setup located at the LERMA laboratory at the University of Cergy Pontoise, France. VENUS is composed of an ultra-high vacuum (UHV) chamber, with a base pressure of about 10^{-10} mbar. Atoms/molecules are directed to a sample holder in the UHV chamber by means of a system of four separate beam lines. The temperature of the sample holder can be controlled between 7 K and 400 K. The products are probed by mass spectrometry and Fourier transform infrared spectroscopy.We first studied the penetration depth of H atoms on reactive films of NO and H2CO. We have shown that only the first layer reacts with H, and that hydrogenation processes are dominated by surface effects.We studied the sticking of methanol as a function of surface temperature, from 7 K to 40 K.The composition of the substrate was varied (^{13}CO, H2O, and gold). We were able to demonstrate that the variation in surface temperature has two antagonistic tendencies: textit{i}) The sticking decreases of around 30% with the increase in surface temperature from 7 to about 16 K.textit{ii}) The sticking gradually increases at a temperature above 16 K, until 40 K where it has a value similar to that of 7 K. These profiles show that there is also a slight difference in the degree of sticking at the lowest temperatures for the different substrates. The gold surface has the lowest sticking coefficient and the substrate ^{13}CO (2 ML) has the highest one.The previous experiments (Kimmel et al.2001, Bisschop et al.2006) did not study the variation with temperature and a minimum sticking value of 0.85 ± 0.05 to 14 K was established.The reduction in sticking at very low temperatures is therefore unprecedented and very important (relatively).Finally, we have shown that under the effect of exposure to a beam of H atoms, a methanol film undergoes a decrease in thickness.We believe that the abstraction reactions: CH3OH + H ------> CH2OH + H2, followed by the addition reaction: CH2OH + H ------> CH3OH are responsible for the return to the gas phase of part of the methanol film. This chemical desorption is more efficient on gold than on water. On a sublayer of ^{13}CO, chemical desorption is faster than the formation of 13CH3OH, but remains limited to a fraction of the layer.The impact of the decrease in sticking and the chemical desorption of methanol on the retaining of this COM in the gas phase in molecular clouds remains to be studied, but both aspects point in the direction of a more efficient return to the gas phase than previously estimated
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Colόn, Crespo Lauren J. "Determination of Human Scent Biomarkers for Race, Ethnicity and Gender." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2442.
Full textAbstract:
Human scent has been the focal point of diverse scientific interests and research initiatives for the past several years. The knowledge gained about its composition has favored the advancement of multiple disciplines, and promoted the development of a wide variety of applications. Among these applications is the use of human scent as a resource for Forensic investigations, where scent profiles are often used as evidence to associate individuals to the scene of a crime. The characteristic nature of individual human scent has enabled this type of evidence to be used as a biometric tool for the differentiation of subjects. Nevertheless, the present study discusses a new perspective towards human scent's role and application in Forensic investigations. The foundation of this new perspective consists of employing human scent’s biometric quality to classify individuals using common traits.
In this research study, underarm and hand odor samples were collected from Caucasian, Hispanic and East Asian individuals, of both genders. Subjects were also organized into 3 different age groups: 18-30, 35-50 and 55+ years. Headspace Solid Phase Micro-extraction Gas Chromatography Mass Spectrometry (HS-SPME-GC-MS) was used to create individual scent profiles for the evaluation of subject classification by age, gender and race/ethnicity. Individual classification was assessed through the identification of qualitative and quantitative patterns in the volatile organic compound (VOC) constituents that characterize human scent. Principal Component and Linear Discriminant analyses of the collected scent profiles, led to the identification and validation of characteristic VOC marker combinations for age, gender and race/ethnicity. Statistical analysis facilitated group classification and differentiation on the basis of these traits. Moreover, this study also evaluated the use of solvent extraction as a complementary technique to HS-SPME for human scent analysis. Findings from this assessment revealed that the simultaneous consideration of data from both extraction techniques favors an enhancement of the classification of subjects by means of human scent.
The discoveries achieved in this study represent a significant step for human scent as a forensic tool. The outcome of this research has cleared a new path for further human scent investigation, and highlighted its further relevance to forensic applications.
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Lopes, Aline Soriano. "Extração de especies organoestancias em sedimento por microextração em fase solida acoplada ao forno de grafite e determinação de estanho total por amostragem em suspensão." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248604.
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Orientadores: Marco Aurelio Zezzi Arruda, Fabio Augusto<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica<br>Made available in DSpace on 2018-08-14T14:05:18Z (GMT). No. of bitstreams: 1
Lopes_AlineSoriano_D.pdf: 1700718 bytes, checksum: f6955b16e49880b14a0e1ec26e824561 (MD5)
Previous issue date: 2009<br>Resumo: Este trabalho de Tese visa acoplar a fibra, empregada em microextração em fase sólida (SPME, do inglês solid phase microextraction), ao espectrômetro de absorção atômica com forno de grafite (GF AAS, do inglês graphite furnace atomic absorption spectrometer), visando reter espécies organometálicas volatilizadas nas etapas de secagem e pirólise do GF AAS. O elemento escolhido para avaliar o acoplamento SPME-GF AAS foi o Sn. Primeiramente, a concentração total de Sn foi determinada, utilizando a amostragem em suspensão como estratégia, uma vez que na avaliação da distribuição dos compostos organoestânicos por SPME-GF AAS, a concentração total de Sn seria efetuada a partir de uma suspensão. Para a otimização do método foram avaliados os seguintes parâmetros: solução de preparo da suspensão, e efeito da temperatura de pirólise e atomização. A mistura contendo HF 10 % (v/v) e HNO3 1 % (v/v) foi escolhida para preparar a suspensão, a composição Mg(NO3)2 + NH4H2PO4 apresentou resultados apropriados para ser utilizada como modificador químico convencional, e 1000 e 2200 °C foram as temperaturas ótimas para a pirólise e a atomização, respectivamente. Devido ao efeito de matriz, foi utilizada a técnica de adição de analito para a quantificação de Sn em suspensões de sedimento marinho e de rio, em que os limites de detecção e quantificação calculados foram de 1,5-2,6 e 4,5- 7,6 µg g, respectivamente. Para avaliar o acoplamento SPME-GF AAS, visando à retenção das espécies organoestânicas (butiltricloroestanho, dibutildicloroestanho e tributilcloroestanho) foi utilizada, primeiramente, uma suspensão de sedimento. A suspensão foi sonicada e, em seguida, uma alíquota foi injetada no forno de grafite do GF AAS juntamente com o reagente de derivação (tetraetilborato de sódio - NaBEt4). A programação do forno de grafite foi aplicada e a fibra de SPME foi introduzida no atomizador. Após a retenção das espécies de interesse na fibra, a mesma foi conduzida ao cromatógrafo a gás (CG) para a separação e detecção dos analitos. Os parâmetros instrumentais do CG foram previamente estudados, visando a melhor separação das espécies de interesse. Esses estudos foram realizados utilizando o modo de extração por headspace e SPME (HS-SPME, do inglês headspace-solid phase microextraction). Em relação aos estudos envolvendo suspensões de sedimento no acoplamento proposto SPME-GF AAS, alguns parâmetros foram avaliados frente à retenção das espécies de interesse; entre eles pode-se citar o tipo de fibra, a concentração do reagente de derivação e o pH da reação. Melhores resultados foram observados para a fibra PDMS/DVB, utilizando uma concentração de 0,2 % (m/v) de NaBEt4 para a etilação das espécies de interesse, sendo a reação realizada em pH 5,0. Entretanto, baixa eficiência de retenção (< 20 %) das espécies de interesse em suspensão de sedimento, foi obtida utilizando-se o acoplamento SPME-GF AAS, quando comparada à extração por HS-SPME. Dessa forma, foi realizada uma extração das espécies de interesse das amostras de sedimento, utilizando a energia ultrassônica, anteriormente à sua aplicação no acoplamento proposto SPME-GF AAS. Nesta etapa do trabalho, a temperatura do forno de grafite e o tempo de exposição da fibra de SPME no forno de grafite foram otimizados, visando à máxima eficiência de retenção das espécies de interesse no acoplamento SPME-GF AAS. Os melhores resultados foram observados para temperaturas do forno de grafite de 90 °C, com 986 s de tempo de exposição da fibra no atomizador. Por fim, foram realizados experimentos visando determinar a concentração total de Sn, e reter suas espécies organometálicas simultaneamente, na fibra de SPME, utilizando o acoplamento SPME-GF AAS.<br>Abstract: The goal of this Thesis was coupling the solid phase microextraction (SPME) to graphite furnace atomic absorption spectrometer (GF AAS) for extracting the organometallic species volatilized in the drying and pyrolysis steps of the GF AAS. For evaluating the SPME-GF AAS coupling, Sn was then chosen. Firstly, the total Sn concentration using the slurry sampling strategy was determined, once in the evaluation of the organotin compounds by SPME-GF AAS, the total Sn concentration would be obtained from a slurry solution. Some parameters were evaluated, such as the nature of the solution to prepare the slurry, and pyrolysis and atomization temperatures effects. The mixture of 10 % (v/v) HF plus 1 % (v/v) HNO3 was chosen to prepare the sediment slurries, the Mg(NO3)2 plus NH4H2PO4 was appropriated as conventional chemical modifier, and the values of 1000 and 2000 °C was used as pyrolysis and atomization temperatures, respectively. The analyte addition was used in the Sn determination in sediment (marine and river) samples by slurry sampling due to matrix effects. The detection and quantification limits were calculated as 1.5-2.6 and 4.5-7.6 µg g, respectively. For evaluating the SPME-GF AAS coupling in the extraction of organotin species (butyltrichloride, dibutyldichloride, and tributylchloride), a sediment slurry was firstly used. For this task, the slurry was sonicated and an aliquot of this solution plus the derivatization reagent (sodium tetraethylborate ¿ NaBEt4) were introducted consecutively into the graphite furnace of the GF AAS. Then, the graphite furnace program was applied, and the SPME fiber was exposed into the furnace. After the extraction of organotin species by SPME-GF AAS, the analytes were separated and detected by gas chromatography (GC). Before this procedure, instrumental parameters of the GC were studied. For this task, it was used the conventional extraction by HSSPME (headspace-solid phase microextraction). Related to studies of SPME-GF AAS coupling, employing slurry sampling, some parameters, such as fiber coating, derivatization reagent concentration, pH of the reaction, among others, were evaluated. Satisfactory results were obtained using the PDMS/DVB fiber in the presence of 0.2 % (m/v) NaBEt4 and pH 5.0. However, low extraction efficiency (< 20 %) was obtained, using the SPME-GF AAS coupling for organotin species extraction from sediment slurries, when comparing to HS-SPME extractions. Then, the extraction of organotin species from sediment samples, using the ultrasonic energy was carried out, before the sample introduction into the SPME-GF AAS coupling. In this step, the graphite furnace temperature and the fiber exposure time in the atomizer were optimized. The better results were noted when 90 °C as the graphite furnace temperature was used, and 986 s was attributed as the fiber exposure time into the atomizer. Additionally, the determination of total Sn concentration, and the extraction of organotin species in the SPME fiber, using the SPME-GF AAS coupling, was simultaneously carried out.<br>Doutorado<br>Quimica Analitica<br>Doutor em Ciências
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Pedroso, Marcio Pozzobon. "Projeto e avaliação de um modulador criogenico para cromatografia gasosa bidimensional abrangente (GC x GC)." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250200.
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Previous issue date: 2009<br>Resumo: O objetivo do trabalho foi projetar e avaliar um modulador criogênico para cromatografia gasosa bidimensional abrangente (GC×GC). O modulador projetado foi baseado no modulador de quatro jatos (dois jatos quentes e dois jatos frios); N2 (g) resfriado em N2 (l) foi utilizado como fluido criogênico e N2 (g) aquecido foi utilizado como gás quente. O modulador foi instalado em um cromatógrafo a gás com detector por ionização em chama (GC-FID). O controle das válvulas solenóides e a digitalização do sinal analógico do FID foram realizados por software escrito em ambiente LabVIEW. Os resultados obtidos com o protótipo GC×GC-FID foram comparados com dados obtidos em um GC×GC-FID comercial. O desempenho de ambos os sistemas pode ser considerado equivalente, levando em consideração eficiência cromatográfica e repetibilidade. O protótipo GC×GC-FID foi empregado na análise de diversas amostras, em especial a fração volátil de polpa de abacaxi fresco e desidratado. Os voláteis foram extraídos por microextração em fase sólida através da extração dinâmica do headspace (DHS-SPME). A identificação dos compostos foi feita por cromatografia gasosa acoplada a espectrometria de massas (GC-MS) e avaliação dos índices de retenção. A identificação dos picos no cromatograma GC×GC foi feita através da comparação dos índices de retenção e dos perfis cromatográficos previamente obtidos por GC-MS. Como esperado, a análise por GC×GC-FID apresentou maior detectabilidade e poder de separação quando comparada com GC-FID. Por fim, alguns compostos não identificados por GC-MS foram identificados através de informação obtida pela estruturação cromatográfica da GC×GC.<br>Abstract: The aim of this project was to develop and evaluate a cryogenic modulator for comprehensive two-dimensional gas chromatography (GC×GC). The design of the modulator was based on a cryogenic quad jet modulator; N2 (g) cooled with N2 (l) was used as the cryogenic fluid and heated N2 (g) was used as the hot gas. The modulator was fitted into a gas chromatograph equipped with a flame ionization detector (GC-FID). The control of the solenoid valves and digitalization of the analogic FID signal were performed by software written in the LabVIEW platform. Results obtained with the GC×GC-FID prototype were compared with data from a commercial GC×GC-FID system. The performance of both systems was similar regarding chromatographic efficiency and repeatibility. The GC×GC-FID was employed for analysis of several samples, specially volatile organic compounds of fresh and dried pineapple pulp. The analytes were isolated by dynamic headspace solid phase microextraction (D-HSSPME); identification of the compounds was performed by conventional gas chromatography coupled to mass spectrometry (GC-MS) and evaluation of retention indexes. The identification of the peaks on the GC×GC chromatograms was carried out by comparison of retention indexes and chromatographic profiles previously obtained by GC-MS. As expected, the detectivity and separation power of the GC×GC-FID analysis was significantly better than that of GC-FID. Moreover, the identity of some compounds not identified by GC-MS was assigned after information obtained from GC×GC chromatographic structure.<br>Doutorado<br>Quimica Analitica<br>Doutor em Ciências