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%.

Erebus is a well-studied open-vent volcano located on Ross Island, Antarctica (77◦ 32’ S, 167◦ 10’ E). The volcano is the focus of ongoing research aimed at combining petrologic data and experiments with surface gas observations in order to interpret degassing histories and the role of volatiles in magma differentiation, redox evolution, and eruptive style. This research focus has been driven in part by an abundance of studies on various aspects of the Erebus system, such as physical volcanology, gas chemistry, petrology, melt inclusion research, seismic, and more. Despite this large data set, however, interpretations of Erebus rocks, particularly mafic and intermediate lavas, which are thought to originate from deep within the magmatic plumbing system, have been hindered due to a lack of experimental data. Experimental petrology is a common tool used to understand volcanic plumb- ing systems and to tie observations made at the Earth’s surface to the deep pro- cesses responsible for driving volcanic activity. Experimental petrologists essen- tially recreate natural magma chambers in miniature by subjecting lavas to con- ditions of pressure, temperature, and volatile chemistry (P-T-X) relevant to a natural underground volcanic system. Because many important parameters can be constrained in the laboratory, the comparison of experimental products with naturally erupted ones allows for an understanding of the formation conditions of the rocks and gases we see at the surface. In this thesis, I have employed experimental and analytical petrological tech- niques to investigate the magmatic plumbing system of Erebus volcano. Broadly, the research is focused on volatiles (namely H2O, CO2, and S species) in the Ere- bus system: their abundances, solubilities, interactions, evolution, and ultimate contributions to degassing. Specifically, three key themes have been investigated, each employing their own experimental and analytical techniques. Firstly, the mixed volatile H2O-CO2 solubility in Erebus phonotephrite has been investigated under P-T-X conditions representative of the deep plumbing system of Erebus. Understanding the deep system is crucial because the constant supply of deeply derived CO2-rich gases combined with a sustained energy and mass input into the lava lake suggests a direct link between the phonolite lava lake and the volcano’s ultimate mantle source via a deep mafic plumbing system. Secondly, I have mapped the phase equilibria and evolution of primitive, inter- mediate, and evolved Erebus lavas. The chemistries of these experimental products span the full range of lavas on Ross Island and help to constrain magmatic evolu- tion from basanite to phonolite as well as to elucidate the geometry of the deep Ross Island plumbing system. Finally, lower-pressure experiments representing the shallow plumbing system at Erebus have been performed in order to understand the transport properties of sulfur in alkaline magma. Experiments were performed on natural Erebus basanite and phonolite, which represent the most primitive and evolved lavas from Erebus. A distinct cocktail of C-O-H-S fluid was equilibrated with each experiment, and a wide range of experimental oxygen fugacities was explored. Overall, experiments from this work are the first to place constraints on the en- tire magma plumbing system of Erebus volcano. In addition, experimental results foster a new understanding of non-ideal gas behavior at high pressure, the affinity of CO2 to deeply sourced rift magmas, and the effect of alkalis on fluid transport capabilities in melts.

Orientadores: Helena Teixeira Godoy, Rodrigo Ramos Catharino / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T08:04:00Z (GMT). No. of bitstreams: 1 Sartor_SabrinadeBona_D.pdf: 1858041 bytes, checksum: 4e7eb6a81d989128b6d6cccb656a5a9d (MD5) Previous issue date: 2014 / Resumo: O aroma final de um vinho é formando por um grande número de compostos químicos voláteis, presentes em concentrações variáveis e detectáveis pelo sistema olfativo humano. O estudo da fração volátil de vinhos tem sido o objetivo de muitas iniciativas de estudo, sendo que as metodologias de pesquisa de compostos voláteis em vinhos compreendem etapas fundamentais, tais como: a extração dos compostos, a separação das diferentes moléculas por cromatografia gasosa acoplada à um sistema de detecção e posteriormente, a identificação e quantificação dos compostos voláteis. O objetivo deste trabalho foi extrair, identificar e quantificar os compostos voláteis de vinhos Chardonnay produzidos em diferentes regiões brasileiras utilizando microextração em fase sólida no modo de headspace (HS-SPME) e cromatografia gasosa acoplada à espectrometria de massas tandem (GC-MSMS). As amostras foram produzidas nas principais regiões vitícolas brasileiras: Serra Gaúcha e Campanha (Rio Grande do Sul), Serra Catarinense e Região de Altitude (Santa Catarina) e Sul de Minas (Minas Gerais). O método de extração de compostos de aroma foi desenvolvido usando a técnica de HS-SPME e GC-MS/MS e análise multivariada com delineamento composto central rotacional (CCRD) e metodologia de superfície de resposta para obtenção de um ponto ótimo de extração. As condições otimizadas foram temperatura (°C) e tempo (minutos) de extração. A otimização multivariada das condições de extração por HS-SPME permitiu avaliar os efeitos de tempo e temperatura de extração nesta metodologia, permitindo a obtenção de um ponto ótimo de extração, 30°C e 45 minutos, dos representantes das classes dos principais compostos voláteis presentes em vinhos Chardonnay. A análise qualitativa e quantitativa da fração volátil dos vinhos foi realizada usando a técnica de GC-MS/MS. O método foi validado e aplicado para a análise de 31 compostos voláteis nas amostras de vinhos Chardonnay. Destes compostos analisados, 30 foram utilizados para a realização de PCA e HCA visando a diferenciação regional dos vinhos. A Análise de Componentes Principais (PCA) e Análise de Agrupamento Hierárquico (HCA) foram realizadas com os dados obtidos. Os resultados obtidos demonstraram que as amostras produzidas em Minas Gerais e na Serra Gaúcha possuem marcadores olfativos herbáceos e vegetais, enquanto as amostras produzidas na região da Campanha/RS, Serra Catarinense e Região de Altitude/SC possuem marcadores florais e frutados, reforçando o papel da origem geográfica na formação e diferenciação do aroma dos vinhos analisados / Abstract: Wine aroma wine is formed by a large number of volatile chemical compounds, present in variable concentrations and detectable by the human olfactory system.The study of the volatile fraction of wines has been the aim of many research studies and those analytical methods including basic steps, such as: isolation and extraction of matrix, separation and detect by gas chromatography coupled to a detection system and finally, the identification and quantification of the individual components. The aim of this study was to extract, identify and quantify the volatile compounds of brazilian Chardonnay wines, produced in different regions, using solid phase microextraction in headspace mode (HS-SPME) and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Samples were produced in the main wine producing regions in Brazil: Serra Gaúcha and Campanha (Rio Grande do Sul state), Santa Catarinense and Região de Altitude (Santa Catarina state) and Sul de Minas (Minas Gerais state). A extraction method of aroma compounds was developed and optimized using HS-SPME and GC-MS/MS and multivariate central composite rotational design (CCRD) with response surface methodology to obtain an optimum extraction condition. The optimized conditions were temperature (°C) and time (minutes) of extraction. Multivariate optimization of extraction conditions for HS- SPME allowed to evaluate the effects of time and temperature of extraction allowing the achievement of the optimum extraction point of compounds representatives of the main classes of volatile compounds in Chardonnay wines. The optimum point observed is at temperature in 30 ° C and time in 45 minutes. A method for qualitative and quantitative analysis of the volatile fraction of wines was carried out using the technique of GC-MS/MS. The method was validated and used for the analysis of 31 volatile compounds in samples of Chardonnay wines. From compounds analyzed, 30 compounds were used to perform PCA and HCA targeting regional differentiation of wines. The Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were performed with the data obtained. The results showed that samples produced in Minas Gerais and Serra Gaúcha shows high concentration of compounds with vegetal and herbaceous notes. Meanwhile, samples of Campanha, Serra Catarinense and Região de Altitude shoes high concentration of compounds with floral and fruity notes. These results reinforce the role of geographical origin in the formation and differentiation of aroma in wines / Doutorado / Ciência de Alimentos / Doutora em Ciência de Alimentos

In certain European countries and the United States of America, canines have been successfully used in human scent identification. There is however, limited scientific knowledge on the composition of human scent and the detection mechanism that produces an alert from canines. This lack of information has resulted in successful legal challenges to human scent evidence in the courts of law. The main objective of this research was to utilize science to validate the current practices of using human scent evidence in criminal cases. The goals of this study were to utilize Headspace Solid Phase Micro Extraction Gas Chromatography Mass Spectrometry (HS-SPME-GC/MS) to determine the optimum collection and storage conditions for human scent samples, to investigate whether the amount of DNA deposited upon contact with an object affects the alerts produced by human scent identification canines, and to create a prototype pseudo human scent which could be used for training purposes. Hand odor samples which were collected on different sorbent materials and exposed to various environmental conditions showed that human scent samples should be stored without prolonged exposure to UVA/UVB light to allow minimal changes to the overall scent profile. Various methods of collecting human scent from objects were also investigated and it was determined that passive collection methods yields ten times more VOCs by mass than active collection methods. Through the use of polymerase chain reaction (PCR) no correlation was found between the amount of DNA that was deposited upon contact with an object and the alerts that were produced by human scent identification canines. Preliminary studies conducted to create a prototype pseudo human scent showed that it is possible to produce fractions of a human scent sample which can be presented to the canines to determine whether specific fractions or the entire sample is needed to produce alerts by the human scent identification canines.

O principal polo produtor de banana no estado de São Paulo está na Divisão Regional e Agrícola de Registro, que se estende do Vale do Ribeira até o litoral sul do estado. Nesta região, a produção de banana é a principal atividade dos produtores rurais e é responsável pela principal demanda de insumos e serviços de comercialização. No entanto, o Vale do Ribeira se caracteriza por ser uma região com baixos níveis de tecnologia e mecanização e a qualidade de vida é bastante baixa, fatores que contribuem para a baixa produtividade da banana. Este trabalho teve como objetivo estabelecer os efeitos que a proximidade da biodiversidade nativa da Mata Atlântica promove nos atributos físico-químicos e bioquímicos do fruto da bananeira, em decorrência da proximidade da biodiversidade. Duas parcelas foram escolhidas para fornecer as amostras posteriormente analisadas quanto a parâmetros fisiológicos, químicos e bioquímicos: a parcela \"Controle\" plenamente inserida em um bananal convencional e a parcela \"Biodiversidade\" com 60% de seu perímetro rodeado pela biodiversidade da Mata Atlântica. Foram feitas as seguintes avaliações nos frutos colhidos destas parcelas: análise dos perfis de etileno e CO2 endógenos por cromatografia gasosa, quantificação de amido por método enzimático, e açúcares solúveis por CLAE-DAD, análise de textura (penetrômetro) e cor (colorímetro), determinação de compostos voláteis relacionados ao aroma por cromatografia gasosa e espectrometria de massas. Além de avaliações em campo de incidência e severidade de pragas e doenças, de luminosidade, radiação fotossinteticamente ativa, análise de solo e foliar, monitoramento da Umidade Relativa e temperatura. Os resultados mostraram que as plantas na parcela próxima à Mata Atlântica foram menos atacadas pela Sigatoka Negra (cerca de 15%) quando comparada à parcela Controle (cerca de 36%). Nos frutos colhidos, foram encontradas diferenças nos padrões de etileno, respiração, textura, cor, açúcares e perfil de compostos voláteis. Os resultados relativos ao perfil destes compostos mostraram alterações na rede de vias de biossíntese de compostos voláteis diferentes dos comumente detectados em bananas. Compostos típicos de frutos imaturos, conhecidos na literatura como Voláteis de Folhas Verdes (VFVs) foram detectados nos perfis de compostos voláteis de frutos maduros das amostras da parcela Biodiversidade, indicando o desencadeamento de vias metabólicas relacionadas à defesa de plantas, tais como a Via da enzima Lipoxigenase (LOX) e a Via de Biossíntese de Terpenos. Este fato provavelmente teve origem na maior quantidade de sistemas ecológicos originários do fragmento florestal próximo à parcela, que favoreceram uma rede mais rica de relações entre as bananeiras e outros organismos, bem como entre as bananeiras e outras plantas, em comparação às plantas da parcela Controle. Constatou-se que as condições de cultivo no campo têm influência direta sobre o produto final, refletindo no processo de amadurecimento dos frutos. / In São Paulo, the main banana producing region is the Divisão Regional e Agrícola de Registro, extending from the Vale do Ribeira to the southern coast of the state. In this region, the banana producing is the farmer\'s main activity and is responsible for the main demand of inputs and commercialization services. However, the Vale do Ribeira is characterized as a region with low levels of technology and mechanization and the quality of life is quite low, factors that contribute to low banana\'s productivity. This study aimed to stablish the effects that the proximity of native Atlantic Forest biodiversity promotes on the physical, chemical and biochemical of banana, due to the proximity of biodiversity attributes. Two plots were chosen to provide samples subsequently analysed for physiological, biochemical and chemical parameters: a control plot fully inserted into a conventional banana produce and another plot, called by Biodiversity Plot, with 60% of its perimeter surrounded by the Atlantic Forest biodiversity. The following evaluations were made in the fruits harvested from such plots: analyses of endogenous ethylene and CO2 profiles by gas chromatography, quantification of starch by enzymatic method, and soluble sugars by HPLC-DAD, texture analyses (penetrometer) and color (colorimeter), determination of volatile compounds related to flavor by gas chromatography and mass spectrometry. Apart from field evaluations of incidence and severity of pests and diseases, brightness photosynthetically active radiation, soil and leaf analyses, monitoring of relative humidity and temperature. The results showed that the plants in the plot next to the Atlantic Forest were less attacked by Black Sigatoka (about 15%) compared to the plants from the control plot (about 36%). In harvested fruits, differences were found in ethylene profiles, texture, color, sugars and volatile compound profile. The results for the profile of these compounds showed changes in the biosynthetic pathways of volatile compounds network, commonly found in bananas. Typical compounds immature fruit, known in the literature as Green Leaf Volatiles (GLVs) were detected in volatiles from samples of mature fruits portion Biodiversity profiles, indicating triggering of defense-related pathways in plants such as the Lipoxygenase Pathway and biosynthesis of terpenes pathway. This fact probably originated from the most amount of ecological systems originated near the plot forest fragment, wich favored a richer network of relations among the banana plants and other organisms as well as between the banana trees and other plants, compared to plants of the control plot. The growing conditions in the field have direct influence on the final product, reflecting on the fruit ripening process.

In this work, two new spintronic memory cell structures are proposed. The first cell uses the diffusion of polarized spins into ferromagnets with perpendicular anisotropy to tilt their magnetization followed by their dipolar coupling to a fixed magnet (Bhowmik et al., 2014). The possibility of setting the magnetization to both stable magnetization states in a controlled manner using a similar concept remains unknown, but the proposed structure poses to be a solution to this difficulty. The second cell proposed takes advantage of the multiple stable magnetic states that exist in ferromagnets with configurational anisotropy and also uses spin torques to manipulate its magnetization. It utilizes a square-shaped ferromagnet whose stable magnetization has preferred directions along the diagonals of the square, giving four stable magnetic states allowing to use the structure as a multi-bit memory cell. Both devices use spin currents generated in heavy metals by the Spin Hall effect present in these materials. Among the advantages of the structures proposed are their inherent non-volatility and the fact that there is no need for applying external magnetic fields during their operation, which drastically improves the energy efficiency of the devices. Computational simulations using the Object Oriented Micromagnetic Framework (OOMMF) software package were performed to study the dynamics of the magnetization process in both structures and predict their behavior. Besides, we fabricated a 4-terminal memory cell with configurational anisotropy similar to the device proposed, and found four stable resistive states on the structure, proving the feasibility of this technology for implementation of high-density, non-volatile memory cells.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22310号 / 医博第4551号 / 新制||医||1040(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 渡邉 大, 教授 万代 昌紀, 教授 影山 龍一郎 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Indiana University-Purdue University Indianapolis (IUPUI) / Thermal constraints and the quantum limit will soon put a boundary on the scale of new micro and nano magnetoelectronic devices. This necessitates a push into the limits of harnessable natural phenomena to facilitate a post-Moore’s era of design. Requirements for thermodynamic stability at room temperature, fast (Ghz) switching, and low energy cost narrow the list of candidates. Here we show voltage controllable, room temperature, stable locking of the spin state, and the corresponding conductivity change, when molecular spin crossover thin films are deposited on a ferroelectric substrate. This opens the door to the creation of a non-volatile, room temperature, molecular multiferroic gated voltage controlled device.

This master’s theses deals with a production and characterization of hard candies, a type of non-chocolate sweets. Methods of candies production were optimised with focus mainly on boiling temerature which significantly affects product consistency and stability. Production process optimisation was based on methods of sensoric analysis and Karl-Fishcher titration used to determine the water content in the product. Plant extracts Plectranthus amboinicus and Aronia melanocarpa which were applied to hard candies are rich source of bioactive compounds upon which prepared candies were characterised. Optimal conditions for candies production were – boiling temperature 155 °C, volume of citric acid 0,4 %, volume of Plectranthus extract 2 % and volume of Aronia extract 3 %. There were 42 volatile compounds identified in a sample containing 2 % of Plectranthus extract. Based on their content , the most significant compounds were carvacrol (8,44 %), carotol (1,47 %) and levomenthol (0,99 %). Total content of polyfenols was measured to be 7,10 ± 0,55 mgg-1 per 1 g of hard candy sample, antioxidant activity of a sample was 66,19 ± 1,80 gml-1. It was identified that 42 of volatile compounds were present inside the sample with 3 % of Aronia extract. The most significant being carotol (30,67 %), menthol (1,52 %) and thymol (1,39 %). The overall presence of polyphenols was measured to be 13,87 ± 1,12 mgg-1 per 1 g of the candy sample, the antioxidant activity of the sample was 115,00 ± 2,86 gml-1.

Please read the abstract in the section 00front of this document / Dissertation (MSc)--University of Pretoria, 2010. / Chemistry / unrestricted