Dissertations / Theses on the topic 'Wide fraction'

This thesis is concerned with the performance and measurement uncertainty of wire-mesh sensors in different air-water flow regimes in horizontal pipes. It also presents measurements of void fraction and interfacial velocity in such flows. It was found that the interfacial velocity measurements of the wire-mesh sensors were in good agreement with those taken with a high-speed camera and estimates of the uncertainties of these measurements are presented. Drift-flux models were fitted to the measurements and it was found that the parameters of these models were not only sensitive to the flow regime, but also to the liquid superficial velocity.

Gas lift is a means of enhancing oil recovery from hydrocarbon reservoirs. Gas injected at the production riser base reduces the gravity component of the pressure drop and thereby, increases the supply of oil from the reservoir. Also, gas injection at the base of a riser helps to mitigate slugging and thus, improving the performance of the topside facility. In order to improve the efficiency of the gas lifting technique, a good understanding of the characteristics of gas-liquid multiphase flow in vertical pipes is very important. In this study, experiments of gas/liquid (air/water) two-phase flows, liquid/liquid of oil/water two-phase flows and gas/liquid/liquid (air/oil/water) three-phase flows were conducted in a 10.5 m high 52 mm ID vertical riser. These experiments were performed at liquid and gas superficial velocities ranging from 0.25 to 2 m/s and ~0.1 to ~6.30 m/s, respectively. Dielectric oil and tap water were used as test fluids. Instruments such as Coriolis mass flow meter, single beam gamma densitometer and wire-mesh sensor (WMS) were employed for investigating the flow characteristics. For the experiments of gas/liquid (air/water) two-phase flow, flow patterns of Bubbly, slug, churn flow regimes and transition regions were identified under the experimental conditions. Also, for flow pattern identification and void fraction measurements, the capacitance WMS results are consistent with those obtained simultaneously by the gamma densitometer. Generally, the total pressure gradient along the vertical riser has shown a significant decrease as the injected gas superficial velocity increased. In addition, the rate of decrease in total pressure gradient at the lower injected gas superficial velocities was found to be higher than that for higher gas superficial velocities. The frictional pressure gradient was also found to increase as the injected gas superficial velocity increased. For oil-water experiments, mixture density and total pressure gradient across the riser were found to increase with increasing water cut (ranging between 0 - 100%) and/or mixture superficial velocity. Phase slip between the oil and water was calculated and found to be significant at lower throughputs of 0.25 and 0.5 m/s. The phase inversion point always takes place at a point of input water cut of 42% when the experiments started from pure oil to water, and at an input water cut of 45% when the experiment’s route started from water to pure oil. The phase inversion point was accompanied by a peak increase of pressure gradient, particularly at higher oil-water mixture superficial velocities of 1, 1.5 and 2 m/s. The effects of air injection rates on the fluid flow characteristics were studied by emphasizing the total pressure gradient behaviour and identifying the flow pattern by analysing the output signals from gamma and WMS in air/oil/water experiments. Generally, riser base gas injection does not affect the water cut at the phase inversion point. However, a slight shift forward for the identified phase inversion point was found at highest flow rates of injected gas where the flow patterns were indicated as churn to annular flow. In terms of pressure gradient, the gas lifting efficiency (lowering pressure gradient) shows greater improvement after the phase inversion point (higher water cuts) than before and also at the inversion point. Also, it was found that the measured mean void fraction reaches its lowest value at the phase inversion point. These void fraction results were found to be consistent with previously published results.

Les fermentations alcoolique (FA) et malolactique (FML) sont deux étapes importantes de la vinification en rouge dans l’établissement de l’arôme fruité des vins. Afin d’étudier l’importance relative des microorganismes fermentaires, nous étudions l’influence de six couples levures/bactéries lactiques (BL) - trois souches de levures, deux de BL - sur la modulation des notes fruitées de différents vins rouges de Bordeaux. Une première approche analytique montre l’influence prédominante de la souche de levures sur la concentration de plus de 70 marqueurs potentiels de la note fruitée. L’étude particulière des esters montre que l’effet levures observé dès la fin de la FA persiste au cours du temps malgré la FML et les modifications engendrées par le vieillissement du vin. L’étude sensorielle conforte l’influence majeure des levures sur la modulation de l’arôme fruité des vins rouges à différents temps d’élevage. Néanmoins, les résultats obtenus suggèrent l’implication d’autres composés aromatiques dans la modulation de la note fruitée des vins, non quantifiés dans la première partie de cette étude. Un travail de fractionnement d’extraits de vin par HPLC permet par la suite l’identification d’une fraction d’intérêt impliquée dans des variations aromatiques liées à la souche de levures. L’analyse de cette fraction par chromatographie en phase gazeuse n’a pas permis d’identifier le ou les composés impliqués. Nous avons néanmoins mis en évidence une thiophénone qui pourrait agir en tant que masque de l’arôme fruité, ainsi qu’un ester hydroxylé qui pourrait s’avérer être un marqueur intéressant de l’activité bactérienne et dont l’effet exhausteur de notes fruitées est également envisagé comme perspectives
Alcoholic (AF) and malolactic (MLF) fermentations are important steps in red winemaking for the revelation of wine fruity aroma. To investigate the relative importance of fermentative microorganisms, we studied the influence of six yeasts/lactic acid bacteria (LAB) combination - three yeast strains, two LAB - on Bordeaux red wines fruity notes modulation. A first analytical approach showed the predominant influence of yeast strain on the concentration of more than 70 potential fruity note markers. Special study of esters showed a yeast strain effect since the end of FA that persists over time, despite MLF and changes caused by wine aging. Sensory studies also highlighted the major influence of yeasts on red wines fruity aroma modulations at different aging steps. Nevertheless, results suggested the role of other aromatic compounds in fruity note modulation, not quantified in the first part of this study. The study of fractions made by HPLC with wine organic extracts enables the identification of an interested fraction involved in aromatic variations related to the yeast strain. Analysis of this fraction by gas chromatography has not allowed identifying compounds involved in these organoleptic variations. However, we highlighted a thiophenone that could act as a mask of fruity aroma and a hydroxylated ester that could be an interesting marker of bacterial activity. Its role as enhancer of fruity esters aroma is also considered

The aim of submitted diploma thesis is the study of non-isothermal crystallization kinetics of polylactide (PLA) with selected agents (1 %) and observation of the emerging crystalline structure under polarizing optical microscope. The agents were talc, a mixture of organic salts with the addition of amorphous SiO2 (HPN 68L) and zinc stearate (HPN 20E) and LAK-301 (potassium salt of 5-dimethylsulfoisophtalate), which is a nucleating agent developer for PLA. The PLA matrix served as a reference. Non-isothermal crystallization took place on a differential scanning calorimeter at cooling rates () 0,3; 0,5; 0,7; 1; 1,5; 2 °C/min After non-isothermal crystallization, the crystalline fraction (Xc) od PLA was evaluated from X-ray diffraction analysis, and the supramolecular structure was observed after chemical degradative etching using confocal laser scanning microscope. The crystallization kinetics were evaluated by the methods of Jeziorny and Mo and the activation energy of the crystallization was determined according to the Friedmann method. All prepared materials were amorphous (Xc 40 % for up to 1,5 °C/min). However, for LAK-301, Xc decreased to 30 % already at the = 2 °C/min and it can be assumed that with increasing its nucleation activity will decrease. A spherulitic structure was observed in all samples, but the number and size of spherulites decreased with increasing and the appearance varied according to the type of agent. Both kinetic models proved to be unsuitable for materials with low Xc and the highest because the rate of crystallization did not change. With the Jeziorny method, it was possible to evaluate the kinetics only for the relative crystallinity Xt = 29–50 % and with the Mo method it was not possible to evaluate the data for the highest for PLA matrix and sample with HPN 68L. The samples with LAK-301 and HPN 68L showed the lowest activation energy.

Cancer is one of the leading causes of death in countries throughout the world. Increase in the production of Reactive Oxygen Species (ROS) has been implicated in many human disease processes, including aging and carcinogenesis. Detoxification of ROS in the cell is provided by both enzymatic and non-enzymatic systems, which constitute the antioxidant defence systems and is crucial to the survival of organisms. The cancer inhibitory propierties of antioxidant compounds such as polyphenols have been well established in experimental and epidemiological studies, showing the intake of these antioxidants within our diet can carry out an effective protective action toward the oxidative stress created in the body by imbalance between ROS and its endogenous defence mechanism. However, the molecular mechanisms responsibles for these effects are not so well known and more studies are needed to provide clear evidence of their protective effects.

The aim of this study is to determine and compare the posible antitumoral properties of several polyphenolic fractions, obtained from the extraction and fractionation of wine by-products consisting of grape skins, seeds and stems. These polyphenolic fractions have high antiradical potential and are mainly composed by flavanol monomers with or without gallate groups, glycosylated flavonols and mostly procyanidin oligomers. The effect of these fractions is analysed on cancer cells at cellular and metabolic levels. Moreover, as solar radiation in the UV range is the major source of adverse reactions in the skin and is one of the most efficient environmental carcinogen known, the possible capacity of these fractions to protect against cellular damage induced by ultraviolet radiation is evaluated and compared.

The results obtained in this study let us to confirm the polyphenolic fractions studied are very specific antiproliferative agents with very low cytotoxicity to non-proliferative normal cells, such as peripherial blood lymphocites (PBLs). Moreover, treatment with these fractions results in intracellular metabolic changes, restricting the ability of tumoral cells to proliferate and inhibiting glycolysis, being higher for the fraction rich in ECG containing oligomeric flavanols.
Like for the study of antitumoral effect at cellular and metabolic levels, the results obtained in the analysis of the protective capacity of these polyphenolic fractions against UV-induced damage, confirm them as potential natural chemopreventive agents.

Briefly, the results obtained in this study let us to conclude the polyphenolic fractions rich in procyanidin oligomers and gallate esters are the most efficient as antitumoral agents, active at both cellular and metabolic levels with low cytotoxicity. Additionally, polymerization and percentge of galloylation are also important in the efficacy of the polyphenolic fractions as protectors against damage induced by ultraviolet radiation, suggesting they may be useful for the prevention and treatment of a variety of solar UV light-induced human skin disorders.

This thesis describes the development and testing of two apparatuses; a vibrating wire viscometer to measure the viscosity of fluids over a wide range of temperature and pressure; and a microwave cavity resonator to measure dew points, gas phase densities, and liquid drop out volumes. Viscosity and density of downhole fluids are very important properties as their values can determine the economic viability of a petroleum reservoir. A vibrating wire viscometer has been developed with an electrically insulating tensioning mechanism. It has been used with two wires, of diameters (0.05 and 0.150) mm, to measure the viscosity of methylbenzene and two reference fluids with viscosities of (10 and 100) mPa·s at T = 298 K and p = 0.1 MPa, at temperatures in the range (298 to 373) K and pressures up to 40 MPa, where the viscosity covers the range (0.3 to 100) mPa·s, with a standard uncertainty < 0.6 %. The results differ from literature values by < ±1 %. The results demonstrate that increasing the wire diameter increases the upper operating viscosity range of the vibrating wire viscometer, a result anticipated from the working equations. For the microwave cavity resonator, the method is based on the measurements of the resonance frequency of the lowest order inductive-capacitance mode. The apparatus is capable of operating at temperatures up to 473 K and pressures below 20 MPa. This instrument has been used to measure the dew pressures of {0.4026CH4 + 0.5974C3H8} at a temperature range from 315 K up to the cricondentherm ˜ 340 K. The measured dew pressures differ by less than 0.5 % from values obtained by interpolation of those reported in the literature, which were determined from measurements with experimental techniques that have quite different potential sources of systematic error than the radio-frequency resonator used here. Dew pressures estimated from both NIST 14 and the Peng-Robinson equation of state lie within < ±1 % of the present results at temperature between (315 and 337) K while predictions obtained from the Soave-Redlich-Kwong cubic equation of state deviate from our results by 0.4 % at T = 315 K and these differences increase smoothly with increasing temperature to be -2.4 % at T = 337 K. Densities derived from dielectric permittivity measurements in the gas phase lie within < 0.6 % of the values calculated from the Soave-Redlich-Kwong cubic equation of state and about 1 % from values obtained with the Harvey and Prausnitz correlation based on a mixture reduced density. The calculations with Kiselev and Ely parametric crossover equation of state (based on Patel-Teja EOS) gave deviations < 0.7 %. Liquid volume fractions, in the 2-phase region, were measured from (0.5 to 7) cm3 in a total volume of about 50 cm3 at different isochors. The measured liquid volume fractions differ from values obtained with the Soave-Redlich-Kwong cubic equation of state by between 0 and 3 % at T < 326 K and about 8 % on approach to the critical region. The large deviations observed in the critical region were anticipated because of the known poor performance of the cubic equations of state with regard to the calculation of the liquid density in the vicinity of the critical temperature.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.17.08 – процеси та обладнання хімічної технології. – Національний технічний університет «Харківський політехнічний інститут» Міністерства освіти і науки України, Харків, 2018 р. Дисертація присвячена вирішенню актуальної науково-прикладної задачі підвищення потужності рекуперації теплової енергії в процесах ректифікації широкої фракції легких вуглеводнів (ШФЛВ) і супутніх їм процесах. За допомогою програмного забезпечення UniSim Design побудовані імітаційні моделі процесів поділу ШФЛВ. Побудова складових кривих процесу ректифікації для існуючої теплообмінної рекуперативної системи дозволили визначити потужність гарячих і холодних утиліт, які процес ректифікації споживає в даний час. В результаті запропонованого проекту реконструкції потужність рекуперації теплової енергії збільшиться на 1102 %, потужності гарячих і холодних утиліт знизяться на 18,37 % і 18,67% відповідно. Аналіз інтегрованої системи теплообміну процесу ректифікації ШФЛВ за допомогою Великої складової кривої (ВСК) дозволив усунути обмежувальний фактор збільшення потужності рекуперації за допомогою створення методу оптимальної інтеграції теплового насосу (ТН) у вже інтегрований процес ректифікації. Побудовані імітаційні UniSim Design моделі інтеграції ТН в обидва процеси ректифікації, які підтвердили збільшення потужності рекуперації теплової енергії в процесі ректифікації ШФЛВ з отриманням пропан пентанової і бутанової фракції, щодо існуючого процесу, на 1590 %, а потужність гарячих і холодних утиліт знижується на 72% і 73% відповідно. При інтеграції теплового насоса в процес ректифікації ШФЛВ з отриманням пентан-гексанової, бутанової і ізобутанової фракцій потужність рекуперації збільшиться на 1233 %, а споживання гарячих і холодних утиліт знижується на 53% і 54% відповідно. За допомогою ВСК процесів ректифікації вперше побудований тепловий профіль комплексу різних установок ректифікації ШФЛВ, аналіз якого дозволив визначити додаткові місця розташування рекуперативних теплообмінників, що дало можливість збільшити потужність рекуперації теплової енергії на 23,4 МВт. В результаті інтеграції комплексу установок загальна потужність рекуперації теплової енергії збільшилася на 1986 %, а потужність гарячих і холодних утиліт зменшилася на 51%. В дисертації також вирішена задача збільшення потужності рекуперації теплоти в існуючій двопотокової теплообмінній системи і створено метод та програма розрахунку додаткової площі поверхні теплообміну для двопотокових систем рекуперації теплової енергії.
Thesis for granting the Degree of Candidate of Technical sciences in specialty 05.17.08 «Processes and equipment of chemical technology»  National Technical University «Kharkiv Polytechnic Institute», 2018. The thesis is devoted to solution of actual scientific and applied problem of increasing the capacity of recovering thermal energy in the processes of distillation of wide fraction of light hydrocarbons (WFLH) and associated processes. On the basis of theoretical analysis of the system flow of the gas rectification process using the methods of pinch analysis were constructed a grid diagram and a flowsheet of the reconstruction project and the main parameters of the new heat exchangers were defined. The power of recuperation thermal energy will increase by 1102 %, power of hot and cold utilities will be reduced by 18,37 % and 18,67%, respectively in the proposed project. Based on simulation UniSim Design model of integration of HP in both of the process of rectification, which confirmed the increasing power of recovering thermal energy in the process of gas rectification with production of propane-butane and pentane fractions with respect to the existing process, 1590 %, and the power of hot and cold utilities is reduced by 72% and 73%, respectively. When you integrate the heat pump into the process of rectification of raw WFLH from the receipt of pentane-hexane, butane and isobutane factions power recovery will increase by 1233 % and the consumption of hot and cold utilities is reduced by 53% and 54%, respectively. Using the GCC processes built for the first time the thermal profile of the set of different plants fractionation WFLH, the analysis of which allowed increasing the capacity of thermal energy recuperation at 23.4 MW. In the end, the Total Site integration of complex installations, the total capacity of thermal energy recuperation increased by 1986 % and power of hot and cold utilities decreased by 51%.

Дисертація на здобуття наукового ступеня кандидата технічних наук (доктора філософії) за спеціальністю 05.17.08 «Процеси та обладнання хімічної технології» (16 – Хімічна та біоінженерія) – Національний технічний університет «Харківський політехнічний інститут» Міністерства освіти і науки України, Харків, 2017 р. Процеси поділу і зокрема процеси ректифікації газових і рідких сумішей є одними з найбільш енергоємних у промисловості. За оцінками експертів, до 5% всієї енергії, яка використовується людством, споживається саме в цих процесах. Тому дисертація присвячена вирішенню актуальної науково-прикладної задачі підвищення потужності рекуперації теплової енергії в процесах ректифікації широкої фракції легких вуглеводнів (ШФЛВ) і супутніх їм процесах. В результаті аналітичного огляду публікацій виконана класифікація методів збільшення потужності рекуперації теплової енергії в хіміко-технологічних процесах з метою зниження питомого енергоспоживання в промислових процесах. Розглянуто методи внутрішньої теплової інтеграції ректифікаційних колон, як з інтеграцією теплового насоса (ТН) з колоною, так і без інтеграції ТН. Розглянуто роботи, які пов'язані з застосуванням методів Пінч-аналізу для збільшення потужності процесів рекуперації теплоти на установках хімічних виробництв. Зроблено аналіз робіт, які присвячені збільшенню питомої потужності рекуперації теплоти в територіальних виробничих комплексах (Total Site Integration). В аналізі публікацій окремо відзначені роботи піонерів в області Інтеграції Процесів: професора Б. Линнхоффа, професора Р. Сміта, професора Ї. Клемеша, а також роботи вітчизняних вчених: професора Л. Л. Товажнянського, професора П. О. Капустенко, професора Л. М. Ульєва. Аналіз літературних даних дозволив зробити постановку завдань для збільшення питомої потужності процесу рекуперації теплової енергії на установках ректифікації ШФЛВ з отриманням пропан-пентанової, пропан-гексанової, бутанової і ізобутанової фракцій та підібрати методи їх вирішення. Для вирішення даної задачі був обстежений процес рекуперації теплової енергії у цеху газофракціонування нафтопереробного заводу, що складається з двох ліній ректифікації ШФЛВ. Одна з них – отриманням пропан-пентанової, бутанової фракцій, інша – отриманням пентан-гексанової, бутанової і ізобутанової фракцій. Також в територіальний промисловий комплекс входить установка легкого гідрокрекінгу. За допомогою програмного забезпечення UniSim Design побудовані імітаційні моделі процесів поділу ШФЛУ. Аналіз технологічних процесів, їх регламентів, даних імітаційних моделей дозволив записати потокову таблицю процесів, що досліджуються, ця таблиця є цифровим чинником технологічних потоків, що беруть участь в системі теплообміну установки. Також побудована сіткова діаграма існуючої енерготехнологічної системи установки ректифікації ШФЛВ з отриманням пропан-пентанової і бутанової фракцій і визначена потужність процесів рекуперативного теплообміну на установці Qrec = 1230 кВт. Дані, які отримані у результаті, аналізу, дозволили побудувати складові криві процесу ректифікації для існуючої теплообмінної рекуперативної системи і визначити потужність гарячих QHmin =67274 кВт та холодних утиліт QCmin= 65982 кВт, що процес ректифікації споживає в даний час. Аналіз складових кривих дав можливість визначити мінімальну різницю температур між теплоносіями в теплообмінному обладнанні установки ΔТmin = 30 С. Ця величина є параметром, який показує можливість збільшення потужності рекуперації теплової енергії в процесі. На основі теоретичного аналізу системи технологічних потоків процесу ректифікації ШФЛВ, з застосуванням методів пінч-аналізу, визначено оптимальне значення мінімальної різниці температур між теплоносіями ΔТoptmin = 6 °С, і для цього значення побудована сіткова діаграма та технологічна схема проекту реконструкції системи рекуперативного теплообміну і визначено основні параметри нових теплообмінників. В результаті проекту реконструкції, що було запропоновано, потужність рекуперації теплової енергії стане рівною Qrec = 13575 кВт, тобто збільшиться на 1102 %, потужності гарячих і холодних утиліт будуть рівні QHmin = 54914 кВт, QCmin= 53658 кВт, тобто знизяться на 18,37 % і 18,67% відповідно. Теоретичний аналіз системи теплообміну з допомогою апарату складових кривих дозволив визначить обмежувальний фактор для подальшого збільшення потужності рекуперації теплової енергії. Аналіз інтегрованої системи теплообміну процесу ректифікації ШФЛВ з допомогою Великою складовою кривої (ВСК) дозволив усунути обмежувальний фактор з допомогою створення методу оптимальної інтеграції рекомпресійного теплового насосу (ТН) у вже інтегрований процес ректифікації. Побудовані імітаційні UniSim Design моделі інтеграції ТН в обидва процеси ректифікації, які підтвердили збільшення потужності рекуперації теплової енергії в процесі ректифікації ШФЛВ з отриманням пропан-пентанової і бутанової фракції, у порівнянні до існуючого процесу, на 1590 %, а потужність гарячих і холодних утиліт знижується на 72% і 73% відповідно. При інтеграції теплового насоса в процес ректифікації ШФЛВ з отриманням пентан-гексанової, бутанової і ізобутанової фракцій потужність рекуперації збільшиться від значення 1725 кВт до 21270 кВт, тобто на 1233 %, а споживання гарячих утиліт знизиться від значення 41112 кВт до 22490 кВт, тобто на 53%, холодних утиліт знизиться від значення 42812 кВт до значення 23260 кВт, тобто на 54%. Для подальшого збільшення потужності процесів рекуперації теплової ене-ргії виконано аналіз усього територіального комплексу установок ректифікації ШФЛВ (Total Site інтеграція). За допомогою ВСК процесів ректифікації вперше побудовано тепловий профіль комплексу різних установок ректифікації ШФЛВ, аналіз якого дозволив визначити технологічні потоки, на яких можливо встановити додаткові рекуперативні теплообмінні апарати, що дало можливість збільшити потужність рекуперації теплової енергії на 23,4 МВт. В результаті інтеграції комплексу установок загальна потужність рекуперації теплової енергії збільшилася на 1986 %, а потужність гарячих і холодних утиліт зменшилася на 51% порівняно з утилітами процесів у теперішній час. В дисертації для кожного з запропонованих проектів збільшення потужності рекуперації теплової енергії виконано економічний аналіз. В дисертації також вирішена задача збільшення потужності рекуперації теплоти в існуючій двох-потоковій теплообмінній системі з наявністю утилітних шляхів. Визначено залежності температур теплоносіїв і теплових навантажень на теплообмінному обладнанні від додаткової площі поверхні теплообміну і інтенсивності теплопередачі. Визначено найбільш прийнятне розміщення нової поверхні теплообміну і знайдені значення площі поверхні теплообміну для мінімальної приведеної вартості проекту реконструкції та мінімального терміну окупності. Створено метод, алгоритм і програма розрахунку додаткової площі поверхні теплообміну для двохпотокових систем рекуперації теплової енергії.
Thesis for granting the Degree of Candidate of Technical sciences (PhD degree) in specialty 05.17.08 «Processes and equipment of chemical technology» (16 – Chemical and bioengineering) – National Technical University «Kharkiv Polytechnic Institute» of Ministry of Education and Science of Ukraine, Kharkiv, 2017. The processes of separation and especially rectification of gas and liquid mixtures are one of the most energy consuming in the industry. Under the experts estimation, up to 5% of all energy that is used by the humanity is consumed in these processes. That is why the dissertation work is devoted to the solution of ac-tual research-and-applied tasks of increase of capacity of recuperation of heat energy during the processes of rectification of wide fraction of light hydrocarbons (WFLH) and related processes. As a result of the analytical review of the publication, the classification of the methods of increase of capacity of recuperation of heat energy in chemical techno-logical processes with the purpose of decreasing of specific energy consumption intensity in production processes was carried out. The methods of internal heat in-tegration of rectification columns as with integration of the heat pump (HP) from the column and without integration of HP were considered. The works, which were concerned with the application of Pinch Analysis methods to increase the capacity of recuperation of heat energy on the plants of chemical production, were examined. The analysis of works, which were related to the increase of specific energy consumption of heat in the territorial production complexes (Total Site Integration), was carried out. In the analysis of publications, the works of pioneers in the field of Integration Processes such as Professor B. Linnhoff, Professor R. Smith, Professor J. Klemes, and the works of scientists of our country such as Professor L. L. Tovazhnyansky, Professor P. A. Kapustenko, Professor L. M. Uliev, are mentioned in particular. The analysis of published works allowed putting to the tasks of increasing the specific energy consumption of the process of heat recuperation on the rectification plants WFLH with the production of propane-pentanoic, propane-hexane, butane and isobutene fractions and finding the methods of their solution. To solve the given task, the process of heat energy recuperation in the gas-fractionation shop of the oil refinery, which consisted of two lines of rectification WFLH was studied. One of the tasks is to get propane-pentanoic, butane fractions; the other is to get pentane-hexane, butane and isobutene fractions. In addition, the installation of primary creaking enters into the territorial production complex. The simulation models of the separation of WFLH were designed with the help of the software UniSim Design. The analysis of published works allowed putting to the tasks of increasing the specific energy consumption of the process of heat recuperation on the rectification plants WFLH with the production of propane-pentanoic, propane-hexane, butane and isobutene fractions and finding the methods of their solution. To solve the given task, the process of heat energy recuperation in the gas-fractionation shop of the oil refinery, which consisted of two lines of rectification WFLH was studied. One of the tasks is to get propane-pentanoic, butane fractions; the other is to get pentane-hexane, butane and isobutene fractions. In addition, the installation of primary creaking enters into the territorial production complex. The simulation models of the separation of WFLH were designed with the help of the software UniSim Design.The analysis of published works allowed putting to the tasks of increasing the specific energy consumption of the process of heat recuperation on the rectification plants WFLH with the production of propane-pentanoic, propane-hexane, butane and isobutene fractions and finding the methods of their solution. To solve the given task, the process of heat energy recuperation in the gas-fractionation shop of the oil refinery, which consisted of two lines of rectification WFLH was studied. One of the tasks is to get propane-pentanoic, butane fractions; the other is to get pentane-hexane, butane and isobutene fractions. In addition, the installation of primary creaking enters into the territorial production complex. The simulation models of the separation of WFLH were designed with the help of the software UniSim Design. The analysis of published works allowed putting to the tasks of increasing the specific energy consumption of the process of heat recuperation on the rectification plants WFLH with the production of propane-pentanoic, propane-hexane, butane and isobutene fractions and finding the methods of their solution. To solve the given task, the process of heat energy recuperation in the gas-fractionation shop of the oil refinery, which consisted of two lines of rectification WFLH was studied. One of the tasks is to get propane-pentanoic, butane fractions; the other is to get pentane-hexane, butane and isobutene fractions. In addition, the installation of primary creaking enters into the territorial production complex. The simulation models of the separation of WFLH were designed with the help of the software UniSim Design. The analysis of technological processes, their regulations, and data of simula-tion models permitted to record the production line table of the process under the research. Such table is the numeral factor of the technological flows that take part in the system of heat exchange of the plant. And also, the net diagram of the existing capacity technological system of the rectification plant WFLH with obtaining of propane-pentanoic and butane fractions was established. Moreover, the capacity of the processes of the recuperative heat exchange on the plant Qrec=1230 kW was determined. The data, which were obtained as the result of the analysis, allowed to construct composite curves for the rectification process for the existing heat ex-change recuperative system and determined the capacity of hot QHmin =67274 kW and cold utilities QCmin= 65982 kW, which the process of rectification consumed at that moment. The analysis of the composite curves gave the opportunity to deter-mine the minimum temperature difference between the heat transfer agents in the heat exchanging equipment of the plant Тmin = 30 С. This value is the parameter, which shows the ability to increase the capacity of recuperation of the heat energy in the process. On the basis of the theoretical analysis of the system of technological flows of the process of recuperation WFLH, with the use of Pinch Analysis methods, the optimal value of the minimum temperature difference between heat-transfer agents ΔТoptmin = 6 °С was determined, and for this value a net diagram and technological scheme of the project of reconstruction of the system of recuperative heat exchange were constructed. The main parameters of new heat exchangers were defined. As the result of the project of reconstruction, which was proposed, the ca-pacity of the recuperation of heat energy would be Qrec = 13575 kW that is, it would increase by 1102%, the capacity of hot and cold utilities would be QHmin =54914 kW, that is they would decrease by 18.37% and 18.67% accordingly. The theoretical analysis of the heat exchange system with the help of composite curves device allowed establishing limit factor for the further increase of the capacity of heat energy recuperation. The analysis of the integrated heat exchange system of the process of rectifi-cation of WFLH with the help of the big composite curve (BCC) made it possible to eliminate the limit factor with the help of creation of the method of optimum in-tegration of recompression heat pump (HP) into having been integrated process of rectification. The constructed simulation UniSim Design models of HP integration in both processes of rectification, which proved the increase of the capacity of recuperation of the heat energy in the process of rectification WFLH with obtaining of propane-pentanoic and butane fractions comparing to the existing process, by 1590 %, and the capacity of hot and cold utilities decrease by 72 % and 73 % accordingly were created. During the integration of the heat pump in the process of rectification WFLH with obtaining of pentane-hexane, butane and isobutene fractions, the ca-pacity of recuperation increases from the value 1725 kW to 21270 kW that is, by 1233 %, and the consumption of hot utilities will decrease from the value 41112 kW to 22490 kW, that is by 53 %, cold utilities will decrease from the value 42812 kW to the value 23260 kW, that is by 54%. For the further increase of the capacity of the processes of heat, energy recu-peration the analysis of the whole territorial complex of rectification plants WFLH (Total Site Integration) was conducted. Using BCC of rectification processes, for the first time the heat profile of the complex of different rectification plants WFLH was constructed, the analysis of them made it possible to determine technological flows, on which it was possible to install additional recuperative heat exchangers that helped to increase the capacity of recuperation of heat energy by 23,4 MW. In the result of integration of the plants complex the total capacity of the recuperation of the heat energy increased by 1986 %, but the capacity of hot and cold utilities increased by 51 % comparing with the utilities of processes currently. In the dissertation work, the economic analysis for each of the proposed project of the increase of capacity of recuperation of heat energy was carried out. In the dissertation work, the task of increasing the capacity of recuperation of heat in the existing two-flow heat exchange systems in the presence of utility paths was solved. The dependence of heat carries temperature and thermal loading on heat exchange equipment on additional area of heat exchange surface and intensity of heat transfer were determined. The most suitable placement of the new heat exchange surface was determined and the value of the area of the surface of heat ex-change for the minimum present value of the project reconstruction and minimum payback term were found. The method, algorithm and program of the calculation of the additional area of the surface of the heat exchange for two-flow systems of the recuperation of heat energy were created.

Thesis (PhD)--University of Stellenbosch, 2002.
ENGLISH ABSTRACT: This study describes the design, construction, complete industrialisation and operation of a dual bed vacuum swing adsorption (VSA) demonstration plant, which operates at atmospheric and sub-atmospheric conditions. All design objectives as set out initially were met. The plant removes contaminants such as methanol and water from neutral wine spirit. Neutral wine spirit is a key component of various local and international spirituous products which include liqueurs, gin, vodka, fortified wines and brandy. Neutral wine spirit can chemically be described as the azeotropic mixture of ethanol and water, which occurs at an ethanol content of 96.4 vol. %. Methanol is naturally present in all products from the vine. Fermentation and distillation concentrate methanol even more, and due to physical and chemical characteristics, its separation consumes as much as 45 % of total production costs. Neutral wine spirit is produced by the proven technology of continuous atmospheric distillation. Continuous improvement of the distillation process is limited due to the physical constraints of an old facility, but also due to previous design philosophies and approaches. The VSA plant consists of two adsorbers, packed to a total height of 1.71 m and a diameter of 0.4 m. Adsorption took place at 100 °C and regeneration at the same bed temperature with purified nitrogen gas at 170 °C and a vacuum of 17 kPa (abs). Experiments were divided into Group I and Group II experiments. Group I investigated the ability to separate methanol and water from the azeotrope and to which efficiency it occurred. It consisted of 120 adsorption cycles of 5 minutes each and 60 samples were drawn for analyses. Breakthrough was not allowed to occur. The azeotropic feed was consistently dehydrated to a water content < 0.05 wt %, while methanol was reduced to < 4 mg/100mLAA. The type of 3A molecular sieve (MS 564 CS) was specifically selected to ensure analytic as well as organoleptic compliance with the product specification. Molecular sieve 4A was removed due to organoleptic problems with the product. Group" experiments were performed in the format of a sensitivity analysis. The effects of various process parameters on the methanol breakthrough curves were individually assessed. Eighteen experiments were performed over a period of 8 days, with 86 samples drawn. The duration of an adsorption cycle was 30 minutes, allowing methanol breakthrough to occur. Water was preferentially adsorbed. Negative methanol bed loadings during high water loadings confirmed that water was able to displace methanol molecules. In the presence of water, molecular sieve 3A was capable of adsorbing 0.6 mg methanol/100mLAA, while in the absence of water with synthetically dosed methanol, molecular sieve 3A achieved a maximum loading of 12.3 mg methanol/100mLAA. The latter corresponded with a maximum methanol feed content of 1118 mg/100mLAA. In general, quicker breakthrough occurred at higher flow rates and feed concentrations. Continuous breakthrough caused bed contamination and a 24-hour thermal regeneration was performed following experiment 12. The feed flow rate was increased from the theoretical 50 f/hr to 70 f/hr without any additional capital layout. Selected process conditions were found to be effective in continuously separating methanol from ethanol. Depending on the strategy of integration, profitability studies shows a Return on Investment of between 110.1% - 220.8% for the adsorption project. Adsorption is superior to distillation in the separation of methanol. Due to the level of innovation involved, it is recommended that the contents of this study remain confidential and patent protection is to be extended. This dissertation speaks to both the wine making as well as the chemical engineering fraternity. It seeks to provide credibility to both parties, by clarifying the unknown issues fundamental to the respective disciplines.
AFRIKAANSE OPSOMMING: Hierdie studie definieer die ontwerp, vervaardiging en volledige industrialisasie van 'n dubbelbed vakuum adsorpsie demonstrasie aanleg (VSA) wat by atmosferiese en sub-atmosferiese kondisies bedryf word. Alle ontwerpsdoelwitte is bereik. Die aanleg verwyder selektief metanol en water vanuit neutrale wynspiritus. Neutrale wynspiritus is 'n sleutelkomponent van verskeie spiritualieë in die plaaslike en internasionale wyn en spiritus bedryf. Hierdie produkte sluit in likeurs, jenewer, vodka, gefortifiseerde wyne en brandewyn. Chemies, kan neutrale wynspiritus beskryf word as die azeotropiese mengsel van etanol en water teen 96.4 vol. %. Metanol het 'n natuurlike teenwoordigheid in alle produkte vanaf die wynstok. Gisting en distillasie konsentreer metanol tot 'n hoër mate en weens fisiese en chemiese eienskappe word metanol teen hoë koste vanaf die etanol stroom geskei. Die metanol verwyderingskomponent beloop soveel as 45 % van die produksiekoste van die totale proses. Neutrale wynspiritus word deur die gevestigde tegnologie van kontinue atmosferiese distillasie geproduseer. Kontinue verbetering van die proses word beperk deur die fisiese ouderdom en toestand van die fasiliteite, maar is ongelukkig ook die resultaat van vorige ontwerpsfilosofieë en benaderings. Die adsorbeerders is gepak tot 'n hoogte van 1.71 m met 'n deursnit van 0.4 m. Adsorpsie het by 100°C plaasgevind en regenerasie by dieselfde bedtemperatuur met stikstofgas by 170°C en 'n vakuum van 17 kPa (abs). Eksperimentele werk is in Groep I en Groep II eksperimente verdeel. Groep I het die effektiewe prosesvermoë om metanol en water vanuit die azeotroop te verwyder ondersoek. Dit het bestaan uit 120 adsorpsie siklusse van 5 minute elk. Sestig monsters is getrek vir analise. Deurbreek van metanol was nie toe gelaat om plaas te vind nie. Die azeotropiese toevoer is konsekwent tot 'n water inhoud < 0.05 massa % gedehidrateer is. 'n Metanol inhoud < 4 mg/100 mLAA is bereik. Die tipe 3A molekulêre sif (MS 564 CS) was spesifiek vir die toepassing geselekteer om sodoende 'n analities sowel as organolepties aanvaarbare produk te lewer. Molekulêre sif 4A was verwyder weens die vorming van produk wangeure. Groep II eksperimente is in die vorm van 'n sensitiwiteits analise uitgevoer. Die effek van verskeie veranderlikes is individueel op die metanol deurbreekkurwe getoets. Agtien eksperimente is oor 'n tydperk van 8 dae gedoen, met 'n totaal van 86 monsters wat getrek is. 'n Adsorpsie siklus het 30 minute geduur en het deurbreek van metanol toegelaat. Water is by voorkeur geadsorbeer. Negatiewe metanol bed ladings tydens hoë waterteenwoordigheid toon dat water wel metanolmolekule op 'n adsorpsie-posisie kan verplaas. In die teenwoordigheid van water is 'n bedlading van 0.6 mg metanol/100mLAA verkry, met 'n maksimum van 12.3 mg metanol/100mLAA in die afwesigheid van water. Laasgenoemde verteenwoordig 'n toevoer met 'n metanol inhoud van 1118 mg/100mLAA. In die algemeen is gevind dat 'n toename in toevoer vloeitempo en konsentrasie die tyd vir deurbreek verkort. Kontinue deurbreek het kontaminasie van die bed teweeg gebring en 'n termiese regenerasie is vir 24 ure na eksperiment 12 gedoen. Die teoretiese ontwerps vloeitempo was 50 .elhr, maar resultate het getoon dat die aanleg tot 70 .t'/hr kan verwerk sonder addisionele koste. Die geselekteerde proseskondisies was effektief in die versekering van die kontinue skeiding van metanol en etanol. Die lewensvatbaarheidstudie toon, afhangende van die strategie van integrasie, 'n Opbrengs op Belegging van tussen 110.1% - 220.8%. Adsorpsie het 'n beter skeidingsvermoë as konvensionele distillasie vir die verwydering van metanol vanuit etanol. Weens die vlak van innovasie betrokke, word dit voorgestel dat die inhoud van hierdie studie vertroulik gehou word en dat patent beskerming verleng sal word. Hierdie verhandeling spreek tot beide die wynmaak sowel as chemiese ingenieurs dissiplines. Daar is gepoog om geloofwaardigheid vir beide partye te skep deur die onbekende aspekte van albei dissiplines aan te spreek.

The demand for wireless devices is increasing, new standards are constantly evolving and the operating frequencies are spreading towards higher spectrums. The stress on lowering the voltage supply, the power consumption, the cost and increasing level of integration are the driving forces behind today's RF microelectronics research.
The goal of this thesis is to show the possibility of standard CMOS technology replacing the traditional technologies in RFIC applications, specifically in the design and implementation of frequency synthesizers for 5GHz WLAN applications. The frequency synthesizer is a key building block of WLAN transceivers. To generate multiple frequencies with the resolution required by 5GHz WLAN standards, a fractional-N frequency synthesizer architecture was successfully implemented in 1.8V 0.18mum CMOS technology. To be able to cover the lower and upper 5GHz bands of both HiperLan and 802.11a standards, a wide tuning range quadrature voltage controlled oscillator (VCO), providing a 4-phase output and operating from 5GHz to 6GHz, was used in the phase lock loop (PLL) design. The 5GHz WLAN standards are targeted since they are the most promising, they have few interferers and large data throughputs.
This thesis presents one of the few frequency synthesizers having a large bandwidth of operation and a small resolution reported to-date for this type of application. Also, the digital components used in this frequency synthesizer, namely the fractional-N divider and prescaler have the lowest power consumption reported to-date.

L'objectif de la thèse est la conception d'une machine électrique dédiée à des applications Mild-Hybrid. En assurant certaines fonctionnalités, cette machine permet de réduire la consommation de carburant dans le véhicule et par conséquent réduire la quantité des gaz rejetés. Les contraintes exigées par un tel domaine à la fois pour le couple et la puissance nous amène à étudier les machines synchrone polyphasée à aimants avec un bobinage concentré autour des dents. Cette technologie de bobinage permet d'obtenir des machines de rendement élevé qui sont faciles à fabriquer, réparer et recycler, mais avec un certain niveau d'effets parasites. Afin de trouver un compromis entre ces effets et la capacité à fournir de couple, la thèse concerne l'étude des topologies de bobinage à pas dentaire avec différentes combinaisons Encoches/Pôles. Un modèle analytique constituant un outil permettant de comparer les pertes d'aimants entre les différentes combinaisons est développé. De nombreuses configurations sont comparées afin de faire le choix le plus adéquat pour minimiser les effets parasites. Les topologies rotoriques qui permettent à la machine de présenter une large plage de vitesse sont examinées, mais en tenant compte également de la nécessité de protéger leurs aimants contre des harmoniques nocifs de FMM. Enfin, l'exploitation du degré de liberté offert par une structure à 5 phases est abordée montrant que, le couple peut être significativement boosté en modifiant la structure de rotor. La cohérence de toutes les études analytiques menées dans la thèse est corroborée par des modèles en éléments finis et des mesures effectuées sur un prototype
The aim of this thesis is to design an electrical machine dedicated for Mild-Hybrid applications. By providing certain functionalities, this machine can reduce fuel consumption in the vehicle and therefore reduce the amount of released gases. The challenges imposed by such application on both torque and power lead us to study the multiphase PM machines with concentrated windings. This windings technology provides efficient machines which are easy to manufacture, repair and recycle, but accompanied with a certain level of parasitic effects. In order to find a compromise between these effects and the ability to provide torque, the thesis concerns the study of winding topologies with different Slots/Poles combinations. An analytical model constituting a tool to compare magnet losses between various combinations is developed. Many configurations are compared in order to make the most appropriate choice which minimizes parasitic effects. The rotor topologies that allow the machine to provide a wide speed range are examined, taking into account their role in magnets protection against MMF harmful harmonics. Finally, the exploitation of freedom degree offered by a 5-phases structure is discussed, showing that the torque can be significantly boosted by modifying the rotor structure. The consistency of all analytical studies presented in the thesis is corroborated by finite element models and a prototype measurement

Am 14. Oktober 1999 wurde in Rossendorf die dritte Veranstaltung in einer Serie von Workshops über Meßtechnik für stationäre und transiente Mehrphasenströmungen durchgeführt. Dieses Jahr kann auf auf 11 interessante Vorträge zurückgeblickt werden. Besonders hervorzuheben sind die beiden Hauptvorträge, die von Herrn Professor Hetsroni aus Haifa und Herrn Dr. Sengpiel aus Karlsruhe gehalten wurden. Erneut lag ein wichtiger Schwerpunkt auf Meßverfahren, die räumliche Verteilungen von Phasenanteilen und Geschwindigkeiten sowie die Größe von Partikeln bzw. Blasen der dispersen Phase zugänglich machen. So wurde über einen dreidimensional arbeitenden Röntgentomographen, ein Verfahren zur Messung von Geschwindigkeitsprofilen mit Gittersensoren und eine Methode zur simultanen Messung von Blasengrößen sowie Feldern von Gas- und Flüssigkeitsgeschwindigkeit mit einer optischen Partikelverfolgungstechnik vorgetragen. Daneben wurden interessante Entwicklungen auf dem Gebiet der lokalen Sonden vorgestellt, wie z.B. eine Elektrodiffusionssonde. Neue meßtechnische Ansätze waren ebenfalls vertreten; hervorzuheben ist der Versuch, die Methode der optischen Tomographie für die Untersuchung von Zweiphasenströmungen nutzbar zu machen. Der Tagungsband enthält die folgenden Beiträge: S. John, R. Wilfer, N. Räbiger, Universität Bremen, Messung hydrodynamischer Parameter in Mehrphasenströmungen bei hohen Dispersphasengehalten mit Hilfe der Elektrodiffusionsmeßtechnik E. Krepper, A. Aszodi, Forschungszentrum Rossendorf, Temperatur- und Dampfgehaltsverteilungen bei Sieden in seitlich beheizten Tanks D. Hoppe, Forschungszentrum Rossendorf, Ein akustisches Resonanzverfahren zur Klassifizierung von Füllständen W. Sengpiel, V. Heinzel, M. Simon, Forschungszentrum Karlsruhe, Messungen der Eigenschaften von kontinuierlicher und disperser Phase in Luft-Wasser-Blasenströmungen R. Eschrich, VDI, Die Probestromentnahme zur Bestimmung der dispersen Phase einer Zweiphasenströmung U. Hampel, TU Dresden, Optische Tomographie O. Borchers, C. Busch, G. Eigenberger, Universität Stuttgart, Analyse der Hydrodynamik in Blasenströmungen mit einer Bildverarbeitungsmethode C. Zippe, Forschungszentrum Rossendorf, Beobachtung der Wechselwirkung von Blasen mit Gittersensoren mit einer Hochgeschwindigkeits-Videokamera H.-M. Prasser, Forschungszentrum Rossendorf, Geschwindigkeits- und Durchflußmessung mit Gittersensoren

Am 14. Oktober 1999 wurde in Rossendorf die dritte Veranstaltung in einer Serie von Workshops über Meßtechnik für stationäre und transiente Mehrphasenströmungen durchgeführt. Dieses Jahr kann auf auf 11 interessante Vorträge zurückgeblickt werden. Besonders hervorzuheben sind die beiden Hauptvorträge, die von Herrn Professor Hetsroni aus Haifa und Herrn Dr. Sengpiel aus Karlsruhe gehalten wurden. Erneut lag ein wichtiger Schwerpunkt auf Meßverfahren, die räumliche Verteilungen von Phasenanteilen und Geschwindigkeiten sowie die Größe von Partikeln bzw. Blasen der dispersen Phase zugänglich machen. So wurde über einen dreidimensional arbeitenden Röntgentomographen, ein Verfahren zur Messung von Geschwindigkeitsprofilen mit Gittersensoren und eine Methode zur simultanen Messung von Blasengrößen sowie Feldern von Gas- und Flüssigkeitsgeschwindigkeit mit einer optischen Partikelverfolgungstechnik vorgetragen. Daneben wurden interessante Entwicklungen auf dem Gebiet der lokalen Sonden vorgestellt, wie z.B. eine Elektrodiffusionssonde. Neue meßtechnische Ansätze waren ebenfalls vertreten; hervorzuheben ist der Versuch, die Methode der optischen Tomographie für die Untersuchung von Zweiphasenströmungen nutzbar zu machen. Der Tagungsband enthält die folgenden Beiträge: S. John, R. Wilfer, N. Räbiger, Universität Bremen, Messung hydrodynamischer Parameter in Mehrphasenströmungen bei hohen Dispersphasengehalten mit Hilfe der Elektrodiffusionsmeßtechnik E. Krepper, A. Aszodi, Forschungszentrum Rossendorf, Temperatur- und Dampfgehaltsverteilungen bei Sieden in seitlich beheizten Tanks D. Hoppe, Forschungszentrum Rossendorf, Ein akustisches Resonanzverfahren zur Klassifizierung von Füllständen W. Sengpiel, V. Heinzel, M. Simon, Forschungszentrum Karlsruhe, Messungen der Eigenschaften von kontinuierlicher und disperser Phase in Luft-Wasser-Blasenströmungen R. Eschrich, VDI, Die Probestromentnahme zur Bestimmung der dispersen Phase einer Zweiphasenströmung U. Hampel, TU Dresden, Optische Tomographie O. Borchers, C. Busch, G. Eigenberger, Universität Stuttgart, Analyse der Hydrodynamik in Blasenströmungen mit einer Bildverarbeitungsmethode C. Zippe, Forschungszentrum Rossendorf, Beobachtung der Wechselwirkung von Blasen mit Gittersensoren mit einer Hochgeschwindigkeits-Videokamera H.-M. Prasser, Forschungszentrum Rossendorf, Geschwindigkeits- und Durchflußmessung mit Gittersensoren

Les progrès technologiques dans la fabrication des semi-conducteurs permettent, depuis le début des années 80, de réaliser des dispositifs dans lesquels les électrons sont fortement confinés dans un plan, on parle de système d'électrons bidimensionnels. L'application d'un champ magnétique perpendiculaire intense à ce système permit l'observation des effets Hall quantiques (EHQ), entier en 1980 puis fractionnaire en 1982. En présence du champ magnétique et aux températures extrêmement faibles qui sont concernées, le spectre énergétique des électrons bidimensionnels est quantifié en niveaux de Landau macroscopiquement dégénérés. Le comportement du système est alors déterminé par le facteur de remplissage des niveaux de Landau. L'EHQ entier apparaît autour des valeurs de champ magnétiques qui correspondent à un remplissage entier des niveaux Landau, tandis que son pendant fractionnaire est obtenu autour de certaines fractions du facteur de remplissage ν (ν =1/3, 2/5, 5/2, …) . Alors qu'à remplissage ν entier c'est le comportement individuel des électrons qui gouverne le comportement du système, aux facteurs de remplissage fractionnaires les corrélations électroniques dominent. En raison de ce caractère fortement corrélé, l'EHQ fractionnaire sous-tend un effort de recherche expérimental et théorique important depuis sa découverte. En effet, dans le régime fractionnaire les corrélations fortes induisent des propriétés inédites telles l'existence de quasi-particules de charge fractionnaire, mais elles rendent également la description théorique du système ardue. En 1983, Robert Laughlin proposa une fonction d'onde variationnelle modèle pour la description de l'EHQ fractionnaire observé à remplissage ν=1/3, dont il discuta la validité au regard d'une étude numérique approfondie des interactions entre les électrons. Le succès de cette méthode l'éleva au rang de paradigme, et de nombreuses fonctions d'onde d'essai ont depuis été proposées pour l'explication des effets Hall quantiques observés aux autres facteurs de remplissages. Notamment, la fonction d'onde de Moore et Read s'avère pertinente pour la description de l'EHQ observé à demi-remplissage du second niveau de Landau. Celle-ci suggère l'existence de quasi-particules non-abéliennes qui génère des espoirs importants de par ses applications potentielles en informatique quantique protégée topologiquement. Bien que l'EHQ ait également été observé à demi-remplissage du plus bas niveau de Landau, la nature de l'état sous-jacent est encore débatue. Celui-ci n'est observé que dans les systèmes bicouches et dans les puits larges qui sont au centre de ce travail de thèse. Les puits larges désignent les systèmes dans lesquels l'épaisseur du système d'électrons bidimensionnel ne peut plus être négligée, typiquement à des épaisseurs de l'ordre de 100 nm. En raison du potentiel de confinement ressenti par les électrons, leurs niveaux d'énergies dans la direction du confinement sont quantifiés en sous-bandes. Dans un puits extrêmement fin seule la plus basse sous-bande est peuplée et le degré de liberté correspondant est alors gelé, mais dans les puits large les sous-bandes excitées sont pertinentes. Dans ces conditions l'EHQ fractionnaire à demi-remplissage peut également résulter de la stabilisation d'un état à deux composantes qui peuple les sous-bande excitées. Cet état proposé par Bertrand Halperin en 1983 entre en compétition avec l'état de Moore et Read. En plus de ces deux états, un état métallique de fermions composite est possible, ainsi qu'un cristal électronique de Wigner au comportement isolant. La compétition entre ces différents états est arbitrée par une étude de Monte-Carlo variationnel combinée à des calculs de diagonalisation exacte. La nature de l'état qui est stabilisé dépend de la nature du potentiel de confinement. Dans ce manuscrit de thèse sont discutés les dispositifs de la bicouche, du puits large, ainsi que du puits large en présence d'un biais externe
Due to technological advances in the manufacture of semiconductors enable, in it possible since the early 80s to create devices in which electrons are strongly confined in a plane, thus effectively realizing a two-dimensional electron system. The application of a strong perpendicular magnetic field to this system led to the observation of the integer quantum Hall effect (QHE) in 1980 and fractional QHE in 1982. Under a strong magnetic field the energy spectrum of the two-dimensional electrons is quantified in Landau levels that are macroscopically degenerate, and the behavior of the system is governed by the filling factor of Landau levels. The integer QHE appears around magnetic field values ​​which correspond to an integer filling of the Landau levels, while the fractional equivalent is obtained around certain fractions of the filling factor ν (ν = 1/3, 2/5, 5 / 2, ...). Although for integers values of ν is the individual behavior of electrons dictates the behavior of the system, the fractional filling factors the electronic correlations dominate. Because of those strong correlations, the underlying fractional QHE motivates an important experimental and theoretical research effort since its discovery. Indeed, in the fractional regime the strong correlations induce novel properties such as the existence fractionally-charged quasiparticles, but they also make the theoretical description of the system laborious. In 1983 Robert Laughlin proposed a variational wave function model for the description of the QHE observed at fractional filling ν = 1/3. He discussed the validity of this trial wave function in a comprehensive numerical study of interactions between electrons. The success of this method made it a paradigm, and many test wave functions have been proposed since then for the explanation of quantum Hall effects observed with other fillings factors. In particular, the wave function of Moore and Read is relevant for the description of the QHE observed at half-filling the second Landau level. This suggests the existence of non-Abelian quasiparticles with potential applications in topologically-protected quantum computing. QHE has also been observed at half filling the lowest Landau level, but the nature of the underlying quantum state is still debated; it is observed that in bilayer systems and wells wide. The large wells, which are the focus of this thesis, refer to systems in which the thickness of the two-dimensional electron system cannot be trivially neglected and usually corresponds to a thickness of about 100 nm. Due to the confinement potential felt by the electrons, their energy levels in the direction of confinement are quantized in sub-bands. In a narrow well only the lowest subband is populated and the corresponding degree of freedom is thus frozen, but in a wide well the excited sub-bands are relevant. Under these conditions fractional QHE at half-filling can also result from the stabilization of a two-state components that also populates the excited sub-band. The corresponding trial state, proposed by Bertrand Halperin in 1983, competes with the state of Moore and Read. In addition to these two states, a metal composite fermion state is a relevant trial state as well as an electronic Wigner crystal, the latter behaving as an insulator. The competition between these states is refered by a variational Monte-Carlo study combined with exact diagonalization calculations. The nature of the state that is stabilized depends on the nature of the confinement potential. In this PhD thesis three confinement potentials are studied: the bilayer, the wide well, and the wide well in the presence of an external bias

Dans notre thèse nous nous sommes intéressés à l'étude des fluctuations de courant, de l'admittance quantique ainsi que la densité d'états pour un nano système en interaction. Notre travail se divise en deux parties. Dans la première partie, nous avons étudié les fluctuations de courant et l'admittance pour un conducteur unidimensionnel, en décrivant le système par un liquide de Tomonaga-Luttinger. Nous avons utilisé les techniques de bosonisation et de refermionisation afin d'aboutir à des résultats exacts pour tous les régimes de température, toutes les valeurs de la tension appliquée et toute la gamme des fréquences. Les résultats obtenus sont appliqués à un conducteur cohérent couplé à un quantum de résistance, et aux états de bord dans le régime de l'effet Hall quantique fractionnaire. Dans le cas d'un conducteur cohérent, le bruit non symétrisé à fréquence finie exhibe un profil différent de celui de la théorie de la diffusion, et la conductance à fréquence finie est directement liée au courant. Dans le cas du régime de l'effet Hall quantique fractionnaire, nous avons pu établir que dans certaines limites, il existe une relation entre les corrélations de courant à l'admittance quantique. En particulier, les singularités qui apparaissent dans les corrélations de courant sont celles de l'admittance. Dans la deuxième partie, nous avons étudié un fil quantique connecté à deux réservoirs qui sont représentés par deux impuretés. Le système est décrit par un liquide de Tomonaga-Luttinger. Nous avons établi et résolu l'équation de Dyson pour la fonction de Green retardée. Ce qui permet de calculer la densité d'états pour un fil quantique homogène puis inhomogène. Dans le cas d'un paramètre d'interaction homogène, l'effet des impuretés modifie le profil de la densité d'états. Dans le cas d'un paramètre d'interaction inhomogène, le calcul de la densité d'états est plus difficile et une approche numérique est indispensable.

D. Phil., School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 2011
Whether the neuropil is a static, optimally wired entity, whose components must be balanced in a certain way, is an open question. Are the proportions of the components of the neuropil consistent across different mammalian cortices, especially in primates where the cerebral cortex is complexly organized? This question is interesting because the actual biological underpinnings of complex behaviours and intelligence in big-brained primates remain enigmatic and why they seem qualitatively different from other animals in terms of their cognitive abilities. Understanding changes that may have occurred in the brain, especially at the level of neuropil organization, during the evolution in primates is important to our growing understanding of the intellectual abilities and behaviours exhibited by members of this group. The current series of quantitative studies was aimed at investigating variations in the proportionality of the “wire fraction” in three primate species, the olive baboon (Papio anubis), vervet monkey (Cercopithecus aethiops) and the common chimpanzee (Pan troglodytes), in a range of higher and lower order cortical areas, using a newly developed method that involves standard and immunohistochemical staining techniques to reveal and quantify the various profiles of the fine structures of the cerebral cortex. The results of these studies demonstrate clear layer differences in the wire fraction of the cerebral cortex, and for the most part, consistency in the neuropil wire fraction of the same layer across areas of the cerebral cortex within and between individuals of the same species; however, differences in the wire fraction of the neuropil were associated with changes in brain size. It is apparent that the neuropil is not static, as wiring “optimality” changes with layers and brain size and this has functional implications regarding neuronal processing and behavioural outcomes. The adaptive rationale adopted by evolutionary psychology studies to explain behaviours may be erroneous, as adaptation does not always explain sufficiently the emergence of complex behaviours related to brain size increases, especially in primates.

碩士
國立臺灣科技大學
化學工程系
96
Soybean oil deodorizer distillate (SODD) typically contains about 45% free fatty acids (FFAs) and 20% triacylglycerols (TAGs). In addition, bioactive compounds such as tocopherols, free phytosterols, fatty acid sterol esters (FASEs) and squalene also make up a significant portion of SODD. In this study, the stirred batch desorption extraction was employed to to separate SODD into a nonpolar lipid fraction (NPLF) and a polar lipid fraction (PLF). Most squalene (> 99%) and fatty acid steryl ester (FASE) were concentrated in NPLF whereas most tocopherols and free physterols were concentrated into PLF. Starting with SODD = 20g that contains 4.35% FASEs, 1.92% squalene, 13.19% tocopherols and 9.22% free phytosterols, under the following operation conditions: silica gel to SODD mass ratio = 6 (w/w), hexane for each batch = 800 ml, stirring speed = 1000 rpm, temperature = -6 oC, and total batchs = 70, it was possible to obtain NPLF enriched with FASEs (19.5%, recovery 96.93%) and squalene (9.15%, recovery 100%). The contents of FFAs, TAGs, tocopherols and free phytosterols remained in the NPLF were 11.59%, 1.36%, 4.83%, and 1.45%, respectively. The corresponding recoveries of FFAs, TAGs, tocopherols, and free phytosterols in this fraction were 6.93%, 3.30%, 8.00%, and 3.40%, respectively. The batch extraction employed in this study yielded about the same degree of separation as compared to that of modified soxhlet extraction. However, the advantage of the method of this study is that it can be scaled-up easily.

碩士
國立東華大學
生物技術研究所
91
Abstract Microbial metabolites are general recognized as the important sources of bio-cosmetic products. Some specific microorganisms can produce effective components for skin care through fermentation process. For the development of bio-cosmetics, the merits of safety, low cost and being easy to control will be the most important concerns. To ensure the safety and efficacy of these products will be considered for longer time to be used in human skin without any toxicity. Many bio-cosmetics on the market exaggerated their products have significant efficacy on human skin care. However, most of them neither show the documentation of efficacy nor provided enough scientific data support. The purpose of this study was to examine the effect of protein fractions isolated from rice wine distilled residues on the cell proliferation and collagen production of human dermal fibroblast in vitro. The protein fractions were separated by ionic exchange chromatography and HPLC, and were applied to human skin fibroblast in vitro for screening test. The CPF-A1 fraction increased fibroblast proliferation by 30% and led to stimulation of collagen production by 38% at 96 hours. CPF-A2 inhibited the growth of fibroblast by 15% when concentration was set at 0.24µg/ml, while the content of collagen increased 54% at 96 hours. CPF-A3 had no significant effects on both proliferation and collagen production. Therefore, the CPF-A1 protein fraction possesses the enhancement of cell division and collagen production in human dermal fibroblast without cytotoxicity.

博士
國立中央大學
電機工程學系
106
In this thesis, we demonstrated several kinds of uni-traveling-carrier photodiodes (UTC-PDs) for THz operation. One among such is near-ballistic uni-traveling-carrier photodiode (NBUTC-PD) with P-type charge layer in order to sustain electrons overshot drift-velocity for high-speed bandwidth. The optimum bias for THz operation of this device is usually located at −2 V. However, it has high probability of suffering from higher thermal failure under high output power due to high bias voltage. For the sake of solving this issue, we report another kind of novel collector design by inserting N-type charge layer, N-UTCPD, which optimizes the profile of electric-field distribution in order to further suppress serious Space charge Screening (SCS) effect. The electrons will drift across the collector layer with overshoot velocity even under lower electric-field operation at −1V. Overall, for new structure N-UTC-PD, it still has superiorly high bandwidth (~315GHz) performance, but the new structure also leads to degradation of output power(-3dBm@280GHz); for NBUTC-PD, it has better output power (-1.8dBm) and bandwidth (~325GHz), but this kind of photodiode must need better heat dissipation to avoid thermal failure. However, by using thin absorption layer for ultra-speed bandwidth operation, low responsivity performance in these ultrafast PDs is a big issue. For this reason, we demonstrate a GaAs0.5Sb0.5/In0.53Ga0.47As type-II hybrid absorbers UTC-PD by improving the epi-layer structure to get higher responsivity. According to the measurement results, the flip-chip bonding packaged device with active diameter of 3μm shows moderate responsivity of 0.11A/W (NBUTC-PD:0.08A/W, N-UTC-PD:0.09A/W) along with the recorded, really wide 3-dB optical-to-electrical bandwidth reaching 0.33 THz, among all those reported for long wavelength (1.3–1.55μm) PDs. A 13-mA saturation current and a continuous wave output with power as high as -3 dBm at −1 V are successfully demonstrated at an operating radio frequency (RF) of 0.32 THz under an optical signal with a sinusoidal envelope and ∼63% modulation depth for PD excitation. By use of such kind of PDs, the broadband, integrated photonic transmitter front-end with a novel waveguide-coupled (WR6) is demonstrated. According to the measurement results with the novel design in high gain dual-ridge horn antenna and planar circuit for waveguide excitation, such transmitter achieves recorded-wide fractional bandwidth (100%; 0.1 to 0.3 THz) and high detected power in the receiving-end (31.6 W) at 0.24 THz through wireless transmission.

Trabalho Final do Mestrado Integrado em Medicina apresentado à Faculdade de Medicina
Objetivos: Descrever de que forma a informação obtida pela realização de avaliação funcional por guia de pressão afetou a estratégia de revascularização cirúrgica das artérias estudadas e realizar o seguimento clínico, a um ano, em termos de eventos cardio e cerebrovasculares: morte cardiovascular, enfarte agudo do miocárdio e revascularização não planeada.Métodos: Foi conduzida uma análise retrospetiva de um coorte prospetivo de 32 doentes com doença valvular cardíaca, de um grupo de 298 doentes submetidos a uma avaliação funcional de estenoses coronárias intermédias por guia de pressão no nosso centro entre outubro de 2013 e fevereiro de 2018. As características dos doentes foram retiradas de duas bases de dados. O tempo médio de seguimento clínico foi de 421 dias. Na análise dos dados usaram- se como valores de referência de FFR e IFR um cut-off de ≤0,80 e de ≤0,89, respetivamente.Resultados: Neste estudo foram incluídos 32 doentes com doença valvular cardíaca com indicação cirúrgica, tendo sido avaliadas através do FFR e/ou iFR 42 lesões coronárias. Foram integrados 23 doentes do sexo masculino e a idade média foi de 73 anos. Relativamente aos fatores de risco para doença cardiovascular, 81,3% dos doentes tinham hipertensão, 81,3% eram dislipidémicos, 31,3% tinham diabetes mellitus e 18,8% eram fumadores. A descendente anterior foi a artéria coronária mais vezes envolvida, afetando 23 (54,8%) doentes. Apenas 9 lesões foram classificadas como sendo hemodinamicamente significativas e 6 dessas foram revascularizadas. As 33 lesões restantes não tinham indicação para serem tratadas, no entanto 1 lesão foi revascularizada cirurgicamente.Conclusão: No nosso centro os cirurgiões cardíacos acreditam e atuam consoante os resultados da avaliação funcional. Após um ano de seguimento clínico não se registaram eventos cardiovasculares major nos doentes cuja avaliação funcional tinha sido negativa, confirmando a segurança da utilização do FFR e iFR nesta população com doença valvular grave.
Aims: Describe how the pressure-wire based functional assessment of intermediate coronary stenoses affected the strategy of myocardial revascularization and to perform a one-year analysis in terms of cardiovascular events: cardiovascular death, myocardial infarction and unplanned revascularization.Methods: We conducted a retrospective analysis on a prospective cohort of 32 patients with valvular heart disease out of 298 patients who underwent a pressure-wire based functional assessment of coronary stenosis between October 2013 and February 2018. The baseline data were extracted from two main databases. The median follow-up was 421 days. The cut- off values of 0.80 and 0.89 were used for FFR and iFR, respectively.Results: We included 32 patients with valvular heart disease, which of 42 coronary lesions were functionally assessed by FFR and/or IFR. There were 23 male and 9 female patients and the median age was 73 (66.0-78.0) years. Regarding risk factors for cardiovascular diseases, 81.3% of the patients had hypertension, 81.3% were dyslipidemic, 18.8% were smokers and 31.3% were diabetic. The most frequent lesion was on the left anterior descending coronary artery, affecting 23 (54.8%) patients. Only 9 lesions were classified as hemodynamically significant and 6 of them were treated, either by PCI or CABG. The 33 remaining lesions didn’t have an indication for revascularization, however, one lesion was treated with CABG. There were no major cardiovascular events within 12 months of follow-up.Conclusion: In our centre, the cardiothoracic surgeons believe and act accordingly to the functional assessment evaluation of the coronary lesions. During the follow-up time, no cardiovascular events were registered among the patients which coronary physiological measurements were negative, confirming the safe use of FFR or iFR in this population with valvular heart disease.