The class of water-ice compound known as gas hydrate has been of interest to science for sometime where, for instance, gas hydrates make excellent candidates for studying the interactions of water and gas molecules. They are also of relevance to industry, where they present an interesting material for the separation, transport, and storage of different gases, and also due to the vast quantities of methane gas that are trapped in natural gas hydrate formations. While much is known about the behaviour of many gas hydrate systems at high-pressure, the CO2 hydrate system is less well studied, with apparent hydrate dissociation at just 10 kbar, and (prior to this work) an unsolved crystalline phase in the pressure range 6-10 kbar. In this work the CO2-H2O system has been studied at high-pressure and, by heating samples to the liquid state and observing their behaviour on refreezing, it has been confirmed that there are indeed no hydrate phases in the system above 10 kbar (up to at least 40 kbar). While performing this investigation, an interesting effect of CO2 on the behaviour of water crystallisation was also observed, and additionally, a simple yet effective technique for making solubility measurements in the system at high-pressure has been discovered. Using a combination of neutron and x-ray diffraction techniques, the crystal structure of the previously unsolved ‘HP’ CO2 hydrate phase has been determined by ab-initio methods. It has been found to be a new gas hydrate structure, but is shared by a small number of Zintl compounds, and may also be common to the unsolved C0 phase of H2 hydrate. The structure has a characteristic spiral of guest molecule sites, leading to its suggested label as the spiral hydrate structure (s-Sp). Its composition has been measured as a tri-hydrate, and the compressibility of s-Sp and the low-pressure s-I CO2 hydrate phases have also been measured. On cooling to 77 K it has been discovered that a third CO2 hydrate phase is formed with a significantly larger unit cell, which is thought to possess a structure similar to that of s-Sp, but with an ordered arrangement of CO2 molecules. Finally, a pilot study of the high-pressure behaviour of the binary H2-CO2 hydrate system has been performed. Using Raman spectroscopy it has been found that a new mixed hydrate phase exists in the pressure range 5-15 kbar, and it is speculated that this could exhibit a freely tunable H2/CO2 content, based on suspicion that it forms the s-Sp structure. Additionally, it has been found that H2 and CO2 chemically react at room temperature, when compressed to ~5 kbar in a rhenium gasket. From the Raman spectrum this reaction product has been identified to be aqueous-methanol.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22627号 / 理博第4616号 / 新制||理||1663(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 市川 温子, 教授 中家 剛, 准教授 窪 秀利 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

In this master's thesis a design of door for helium quenching furnace is described. Based on background research, several options for the design have been compared. All calculations were carried out based on structural needs resulting from high pressure gas quenching technology. By the ending of this thesis a mounting procedure and rough cost price estimation is described. Part of master's thesis is also a virtual 3D prototype and a drawing documentation.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24073号 / 理博第4840号 / 新制||理||1692(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 中家 剛, 教授 永江 知文, 准教授 WENDELL Roger / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

A cromatografia é uma técnica de separação cuja classificação se dá por meio do estado físico da fase móvel (líquido, gasoso, supercrítico, entre outros). Dentre as técnicas cromatográficas mais utilizadas e cujo conhecimento é bastante conhecido está a cromatografia gasosa. Embora esta técnica tenha sido bastante estudada existem ainda algumas vertentes que não totalmente estudadas, sendo uma delas a cromatografia gasosa de alta pressão na entrada da coluna (HIPGC). A HIPGC destaca por oferecer vantagens analíticas como alta eficiência, maior velocidade no tempo de análise e também facilita a migração de compostos com alta massa molecular. As desvantagens e dificuldades estão concentradas na instrumentação. O uso de alta pressão requer conexões que suportem tal pressão, sistema de injeção adequado a fim de eliminar vazamentos entre outros. Neste trabalho, sucessivos sistemas instrumentais foram montados visando o desenvolvimento, aprimoramento e avaliação de um sistema instrumental simples e versátil para HIPGC. Na avaliação do sistema foi utilizada coluna capilar empacotada pelo método \"slurry packed\". A escolha da coluna foi realizada a partir de curvas de eficiência de Van deemter. O sistema instrumental desenvolvido para HIPGC é apropriado para pressões de entrada de até 1800 psi. Além disso, este sistema apresentou boa reprodutibilidade nas análises e não apresentou vazamentos. Os resultados mostraram o potencial da técnica HIPGC na redução do tempo de análise. / Chromatography is a separation technique whose classification takes place by means of the physical state of the mobile phase (liquid, gas, supercritical, etc.). Among the most commonly used chromatographic techniques and whose knowledge is well known is gas chromatography. Although this technique has been widely exploited there are some topics which weren\'t fully investigated, one of them being high-pressure chromatography column input (HIPGC). HIPGC shows analytical advantages as high efficiency, faster analysis time and facilitates the migration of compounds with high molecular mass. The main difficulties in HIPGC are found in the instrumentation. The high pressure requires an appropriate connection that works in this range of pressure and one injection system suitable to transport the sample at different pressures. In this work, different instrumental systems were assembled to develop equipment to HIPGC that is simple and versatile. In the system evaluation was used capillary columns packed by methodology\'s \"slurry packed\" were used. The choice of the column was made from van Deemter efficiency curves. The system developed for instrumental HIPGC it is appropriate for inlet pressures up to 1800 psi. Furthermore, this system showed good reproducibility of analysis and didn\'t show leaks. The results showed the potential of HIPGC, such as shorter analysis time.

A cromatografia é uma técnica de separação cuja classificação se dá por meio do estado físico da fase móvel (líquido, gasoso, supercrítico, entre outros). Dentre as técnicas cromatográficas mais utilizadas e cujo conhecimento é bastante conhecido está a cromatografia gasosa. Embora esta técnica tenha sido bastante estudada existem ainda algumas vertentes que não totalmente estudadas, sendo uma delas a cromatografia gasosa de alta pressão na entrada da coluna (HIPGC). A HIPGC destaca por oferecer vantagens analíticas como alta eficiência, maior velocidade no tempo de análise e também facilita a migração de compostos com alta massa molecular. As desvantagens e dificuldades estão concentradas na instrumentação. O uso de alta pressão requer conexões que suportem tal pressão, sistema de injeção adequado a fim de eliminar vazamentos entre outros. Neste trabalho, sucessivos sistemas instrumentais foram montados visando o desenvolvimento, aprimoramento e avaliação de um sistema instrumental simples e versátil para HIPGC. Na avaliação do sistema foi utilizada coluna capilar empacotada pelo método \"slurry packed\". A escolha da coluna foi realizada a partir de curvas de eficiência de Van deemter. O sistema instrumental desenvolvido para HIPGC é apropriado para pressões de entrada de até 1800 psi. Além disso, este sistema apresentou boa reprodutibilidade nas análises e não apresentou vazamentos. Os resultados mostraram o potencial da técnica HIPGC na redução do tempo de análise. / Chromatography is a separation technique whose classification takes place by means of the physical state of the mobile phase (liquid, gas, supercritical, etc.). Among the most commonly used chromatographic techniques and whose knowledge is well known is gas chromatography. Although this technique has been widely exploited there are some topics which weren\'t fully investigated, one of them being high-pressure chromatography column input (HIPGC). HIPGC shows analytical advantages as high efficiency, faster analysis time and facilitates the migration of compounds with high molecular mass. The main difficulties in HIPGC are found in the instrumentation. The high pressure requires an appropriate connection that works in this range of pressure and one injection system suitable to transport the sample at different pressures. In this work, different instrumental systems were assembled to develop equipment to HIPGC that is simple and versatile. In the system evaluation was used capillary columns packed by methodology\'s \"slurry packed\" were used. The choice of the column was made from van Deemter efficiency curves. The system developed for instrumental HIPGC it is appropriate for inlet pressures up to 1800 psi. Furthermore, this system showed good reproducibility of analysis and didn\'t show leaks. The results showed the potential of HIPGC, such as shorter analysis time.

No description available.

During the last 10 years, low pressure carburizing and high pressure gas quenching has become more popular since it is a “new” process and researchers reports that the distortion characteristics gained from these processes is improved in relation to conventional processes. The aim of this work was to investigate the distortions gained from three different heat treatment processes on main shaft gears and crown wheels. Experiments with atmospheric carburization with oil quenching and low pressure carburization with nitrogen gas quenching or oil quenching were made and distortion characteristics gained from these processes were then measured and compared. It was found that components treaded in the relatively new LPC-HPGQ process are similar and often even better than the conventional method. The larger main shaft gear improves the most with newer method but instead gets a lower core hardness and systematic diametrical shrinkage. Some measurements on the crown wheel were also improved but others were affected negatively.

Mesoporous MOFs are currently record holders in terms of the specific surface area with values exceeding 7000 m2 gˉ¹, a textural feature unattained by traditional porous solids such as zeolites, carbons and even by graphene. They are promising candidates for high pressure gas storage and also for conversion or separation of larger molecules, whose size exceeds the pore size of zeolites. The rational strategies for synthesis of mesoporous MOF are outlined and the unambiguous consistent assessment of the surface area of such ultrahighly porous materials, as well as present challenges in the exciting research field, of mesoporous MOFs are discussed. The crystallinity, dynamic properties, functional groups, and wide range tunability render these materials as exceptional solids, but for the implementation in functional devices and even in industrial processes several aspects and effective characteristics (such as volumetric storage capacities, recyclability, mechanical and chemical stability, activation) should be addressed.