Dissertations / Theses on the topic 'Chemical and botanical characteristic'

O tratamento cosmético facial e corporal que emprega o Fango vem sendo muito utilizado em clínicas de estética, com o intuito de melhorar a aparência da pele. A literatura científica carece de informações sobre alguns aspectos desta matéria-prima, como: as condições adequadas para sua coleta, preservando suas características químicas e microbiológicas; as especificações de qualidade da matéria-prima (física, química, microbiológica e toxicológica); e as metodologias analíticas de avaliação. A qualificação do Fango é primordial para o mesmo ser utilizado como matéria-prima de uso cosmético \"tal qual\" na pele ou veiculado em formulações cosméticas, a fim de alcançar a eficácia cosmética e garantir sua segurança de uso. Este trabalho visou a padronização do método de coleta do Fango na fonte e a das seguintes análises: física, físico-química, microbiológica, parasitológica, toxicológica do Fango provindo de Araxá-MG in natura e da lama negra (processada), com intuito de assegurar seu uso qualificado como matéria-prima em formulações cosméticas, uma vez que a literatura científica carece de estudos com este tipo de material. Os resultados obtidos quanto à segurança de uso foram satisfatórios, não ocorrendo a presença de microrganismos patogênicos tais como: Escherichia coli, coliformes fecais e totais, Staphylococcus aureus, Pseudomonas aeruginosa e Candida albicans (antes e depois da maturação), larva migrans e metais pesados. Os demais ensaios realizados para a caracterização do Fango como matéria-prima justificam sua aplicação em produtos cosméticos, como por exemplo, a presença do enxofre com potencial uso em formulações antissépticas e a argila tipo \"caulinita\" em preparações para diminuir a oleosidade da pele.
The facial and body cosmetic treatments applying the \"Fango\" can be seen nowadays on esthetic clinics\' catalogues. The scientific literature up nowadays does not have sufficient informations concerning this product, the correct procedures to collect it from the soil preserving its chemical and microbiological characteristics; the specifications on its physical, chemical, microbiological e toxicological qualities and the analytical methodologies involving on the it evaluation. The Fango\'s qualification is very important because it can be used alone (raw material) or incorporated in cosmetic formulations, in order to evaluate the safety and efficacy of final product. This is the only way it may be applied on cosmetics formulations designed to be applied on human skin. The aim of this research is to standard the collect conditions in thermal springs and standard such analysis: physical aspects, physic-chemical, microbiology, parasitological and toxicological of Thermal mud and Fango from Araxá-MG. The results obtained of this study showed that the Fango from Araxá-MG is safe to be applied in cosmetic formulations or direct on the human skin. The pathogenic microorganism such as: Escherichia coli, Staphylococcus aureus, Pseudomonas aeuruginosa and Candida Albicans were absent on the samples, and the same to Larva migrans and heavy metais. The physic-chemical analysis of Fango from Araxá-MG demonstrated its application in cosmetic products, as its capacity to improvement the skin\'s conditions, e.g. the presence of sulphur with antiseptic proprieties and organic compounds in order to use on the oily skin.

Etude experimentale pour les alliages contenant 0 a 1% de magnesium. Analyse par microscopie electronique en transmission et par analyse enthalpique differentielle de l'evolution de la precipitation. Analyse de la correlation entre la precipitation et les proprietes mecaniques en utilisant des essais de durete et de traction. Seuls les alliages a faible teneur en magnesium s'averent interessants sur le plan d'une application. Influence de la structure (cristallisation et texture) sur les proprietes mecaniques et en particulier sur leur heterogeneite suivant la direction travers-long

Le phenomene de la passivation de l'electrode carbone-lithium utilisee comme pole negatif dans la batterie lithium-ion est d'une importance cruciale dans les caracteristiques du fonctionnement de cette electrode. Il en fixe la capacite reversible (ou utile), la duree de vie et le taux d'autodecharge. Ce travail est une contribution a la comprehension des processus chimiques et electrochimiques survenant a la surface de l'electrode au cours de l'echange du lithium avec une solution electrolytique a base d'un ou plusieurs solvant(s) organique(s) et d'un sel de lithium et conduisant a la formation d'un film de passivation. Apres une presentation bibliographique qui situe l'etude dans son contexte national et international, le travail experimental s'adresse dans un premier temps au role des parametres qui influent sur le processus de passivation tels que la nature de l'anion du sel de lithium et celle du materiau carbone ainsi que la composition de l'electrolyte. La caracterisation de ce film obtenu par des methodes chimiques ou electrochimiques utilise une large gamme de techniques : drx, meb, met, microscopie a champ proche (afm), ir-tf, rmn, esca, atg et dsc. Les techniques electrochimiques sont aussi variees : chronoamperometrie, chronopotentiometrie, impedance complexe et voltamperometrie cyclique. Les resultats obtenus sont pour la plupart originaux. Ainsi, les analyses de la composition chimique du film par esca et par ir-tf sont non seulement completes et nouvelles mais mettent en evidence pour la premiere fois le caractere polymere du film. Ce resultat devrait avoir des repercutions importantes sur l'elaboration ex situ du film pour une etude plus approfondie. L'observation du film forme sur un graphite hautement oriente par afm a permis d'obtenir les images les plus precises et les plus claires jamais publiees. L'etude electrochimique est completee par une synthese chimique du film par une methode originale. L'utilisation de ce film comme electrolyte de type plastifie a ete demontree.

Les transistors a effet champ a contact metal-semiconducteur, non passives, realises sur arseniure de gallium sont sujet a une degradation progressive de leurs performances statiques et dynamiques aux hyperfrequences. Ce defaut de fonctionnement est en parti attribue aux surfaces d'arseniure de gallium situees de part et d'autres de la grille. La stabilisation des composants requiert donc de la passivation de ces zones grace a des materiaux de haute qualite dielectrique realisant une interface stable avec gaas. Dans cette optique, les proprietes physico-chimiques et electriques de films de silice et de nitrure de silicium deposes en phase vapeur assiste par plasma sont etudiees en fonction du rapport des debits des gaz employe, de la temperature du substrat, de la puissance et de la frequence de l'excitation du plasma. . . Cette approche systematique permet de determiner des parametres de depot qui donnent des films ayant tres bonnes proprietes electriques: une resistivite de 10**(14) a 10**(16) ohm. Cm et un champ de claquage superieur a 10**(6) v/cm sont ainsi obtenus apres un recuit dont on soulignera l'importance. Apres mise au point d'une preparation de surface avant depot, la densite d'etats sur la bande interdite du semiconducteur a l'interface gaas/si::(3)n::(4) presente un minimum de 7. 10**(11) ev**(-2). Les depots ainsi optimalises sont utilises pour la passivation des transistors mesfet gaas. Le recouvrement d'un composant par une couche mince introduit une modification de ses caracteristiques statiques; celle-ci est expliquee conjointement par un effet piezo-electrique et par un effet de surface inherent au mode de depot. Suivant les resultats obtenus en tests de fiabilite, le nitrure de silicium s'avere etre le meilleur choix pour reussir la passivation du composant. De plus, des pretraitements par plasma et une meilleure adaptation du procede de fabrication au mode de passivation sont proposes pour ameliorer encore la stabilite a long terme des caracteristiques des transistors

Ce travail se situe dans le cadre de l'application des polymeres conducteurs electroniques (pce) aux batteries rechargeables. L'objectif a ete d'associer deux partenaires aux proprietes electrochimiques complementaires: un pce, la polyaniline, connue pour sa bonne tenue a la charge permanente, une autodecharge faible et une cyclabilite elevee en batterie, et un systeme electroactif base sur le couple redox disulfure/dithiolate qui presente une forte densite d'energie massique. Trois voies ont ete successivement explorees: - la preparation d'une polyaniline substituee sur le cycle par un groupement thiol. L'homopolymere n'a pu etre synthetise simplement car la forme oxydee radicalaire de la dithiodianiline s'adsorbe a la surface des electrodes ou se suroxyde. Nous avons plutot prepare un copolymere aniline-dithiodianiline par voie chimique. Malheureusement, le copoly(aniline-dithiodianiline) n'est pas conducteur et les proprietes electrochimiques des 2 partenaires ne sont ni additives, ni compatibles. - le melange en composite moleculaire pani-polydimercaptothiadiazole (polydmct): ce polydisulfure constitue une electrode reversiblement electropolymerisable qui possede une remarquable densite coulombique massique mais une mauvaise cyclabilite liee a la diffusion des especes thiolates dans l'electrolyte et passivation du metal dans les batteries lithium. Nous avons pu determine la composition optimale de chaque constituant a partir de tests en batteries lithium. La capacite maximale atteinte est 117 ah/kg sous 1 ma cm-2 mais la mauvaise cyclabilite electrochimique du polydmct n'a pas ete resolue. - la fonctionnalisation d'une polyaniline sur l'azote par un groupement carbodithioate: l'action du disulfure de carbone sur une solution de pani sous forme leucoemeraldine permet de greffer environ 80% des azotes en conservant une bonne conductivite (1 s. Cm-1). Le materiau obtenu presente une capacite d'echange accrue de 68% par rapport a la pani de depart. C'est pourquoi ce nouveau polymere utilise comme cathode dans les batteries au lithium devrait donner des resultats interessants

Dupla diplomação Université Libre de Tunis
Since ancient times, natural products, especially those originated from plants have been an important source of therapeutic agents. Currently, several drugs are derived from natural products (plants, animals, bacteria and fungi). Although the focus the synthetic chemistry advances, research on natural pharmaceutical uses has been knowing an important increase in number. In addition, recent data from the pharmaceutical industry show that, for some complex diseases, natural products still represent an extremely valuable source for prospecting new chemical formulations, as they represent unique structures refined by evolutionary mechanisms throughout millions of years. The importance and contribution of natural substances in medicine treatments is especially evident in some Asian and African countries, where 80% of the population depends on traditional medicine, including herbal treatments like in our case of study the Aesculus hippocastanum L. A. hippocastanum (also known as horse chestnut fruits) is an important source of bioactive natural molecules. The biological activity of A. hippocastanum is mainly provided by its secondary metabolites, a class of molecules especially involved in the plant defence system against different threats. Thus, these secondary metabolites play an important role in the adaptation of plants to the environment, effectively participating in their tolerance to various stress factors (pathogen attacks, drought, UV light, among others). The evaluation of the therapeutic value of these metabolites is the subject of many researches, leading to the identification of the main bioactive compounds in this plant. Saponins (triterpenes or steroid glycosides) and phenolic compounds are among the main classes of secondary metabolites. These compounds are of great interest because of their wide range of biological activities, having already been increasingly applied in pharmaceutical related formulation. In order to achieve effective valorisation strategies for these bioactive compounds, it is necessary to optimize separation processes to obtain them from natural sources. In addition to the former extraction procedure, obtaining bioactive compounds also requires other techniques (sometimes slow and expensive) such as purification and identification, which might be a limitation for their industrial application. Accordingly, it is mandatory to develop analytical techniques to improve the extraction process, and achieve rapid separation, miniaturization and coupling methodologies, continuously performed following green chemistry principles. The aim of this work was to demonstrate the antioxidant potential (free radical scavenging effect, reducing power and inhibition of lipid peroxidation), antimicrobial (antibacterial using Gram-positive and Gram-negative strains and antifungal activity) and the absence of toxicity (porcine liver primary cells) of the ethanol/methanol extracts, obtained from the previously mentioned plant and to contribute with updated information on natural sources of bioactive compounds, thorough chemical characterization and possible applications. The extract of A. hippocastanum fruit presented antioxidant activity, without toxicity up to the maximal tested dose and contained different classes of various bioactive molecules, besides carbohydrates lipids, proteins, and minerals. Overall, the information collected from the different analyses realized on the extract samples reveal their potential use in developing new forms of biopharmaceuticals or could be replacing other chemical substances in cosmetic products without interfering with the product composition or affecting its characteristics.
Desde tempos ancestrais, os produtos naturais, especialmente aqueles originários de plantas, têm sido uma importante fonte de agentes terapêuticos. Atualmente, vários medicamentos são derivados de produtos naturais (plantas, animais, bactérias e fungos). Apesar da focalização na química sintética, a pesquisa sobre as aplicações de farmacêuticos naturais tem conhecido um aumento importante. Além disso, dados recentes da indústria farmacêutica mostram que, para algumas doenças complexas, os produtos naturais ainda representam uma fonte extremamente valiosa para a prospeção de novas formulações químicas, pois representam estruturas únicas refinadas por mecanismos evolutivos ao longo de milhões de anos. A importância e contribuição de substâncias naturais nos tratamentos medicamentosos é especialmente evidente em alguns países asiáticos e africanos, onde 80% da população depende da medicina tradicional, incluindo tratamentos à base de plantas, como no nosso caso de estudo, o Aesculus hippocastanum L. O A. hippocastanum (também conhecido como castanha-da-Índia) é uma fonte importante de moléculas naturais bioativas. A atividade biológica de A. hippocastanum é fornecida principalmente pelos seus metabolitos secundários, uma classe de moléculas especialmente envolvidas no sistema de defesa das plantas contra diferentes ameaças. Assim, estes metabolitos secundários desempenham um papel importante na adaptação das plantas ao meio ambiente, participando efetivamente na sua tolerância a diversos fatores de stress (ataques de patógenos, secas, luz UV, entre outros). A avaliação do valor terapêutico desses metabolitos é objeto de muitas pesquisas, levando à identificação dos principais compostos bioativos desta planta. As saponinas (triterpenos ou esteróides glicosilados) e os compostos fenólicos estão entre as principais classes de metabolitos secundários. Estes compostos são de grande interesse devido à sua ampla gama de atividades biológicas, tendo sido cada vez mais aplicados em formulações relacionadas com produtos farmacêuticos Para alcançar estratégias eficazes de valorização destes compostos bioativos, é necessário otimizar o processo de separação desses compostos das suas fontes naturais. Além do procedimento de extração anterior, a obtenção destes compostos também requer outras técnicas (às vezes lentas e caras), como purificação e identificação, que podem ser uma limitação para sua aplicação industrial. Portanto, é obrigatório o desenvolvimento de técnicas analíticas para melhorar o processo de extração e alcançar metodologias rápidas de separação, miniaturização e acoplamento, realizadas continuamente seguindo os princípios da química verde. O objetivo deste trabalho foi demonstrar o potencial antioxidante (efeito de eliminação de radicais livres, poder redutor e inibição da peroxidação lipídica), antimicrobiano (antibacteriano usando estirpes Gram-positivas e Gram-negativas e atividade antifúngica) e a ausência de toxicidade (fígado suíno células primárias) dos extratos etanol/metanol, obtidos da planta mencionada anteriormente e contribuir com informações atualizadas sobre fontes naturais de compostos bioativos, caracterização química completa e possíveis aplicações. No presente caso, o extrato de A. hippocastanum apresentou atividade antioxidante, sem toxicidade até a dose máxima testada e apresentando diferentes classes de várias moléculas bioativas, além de hidratos de carbono, lípidos, proteínas e sais minerais. No geral, as informações recolhidas das diferentes análises realizadas nas amostras de extrato revelam potencial no desenvolvimento de novas formas de produtos biofarmacêuticos como alternativas a outras substâncias químicas em produtos cosméticos sem interferir na composição do produto ou afetar suas características.
This work was funded by programme FEDER-INterreg Spain-Portugal through Project 0377_Iberphenol_6_E.

This work is an account of investigations into the chemistry of members of the Amaryllidaceae and Hyacinthaceae families. The plants of the family Amaryllidaceae are a large group comprising over sixty genera and more than a thousand species. They are widely distributed, but are found more richly in the tropics, with a particularly high density in South Africa, with smaller centers of diversity in Andean South America and the Mediterranean. Amaryllidaceae plants have been extensively used by local traditional healers and have been reported to have numerous pharmacological uses. The alkaloids isolated from this family are a group of isoquinoline alkaloids found exclusively in this family. Plants belonging to two Amaryllidaceae genera were investigated phytochemically, one from each of the sub-tribes Crinineae and Amaryllidineae were investigated phytochemically. Brunsvigia natalensis is used in local traditional medicine to "straighten bones of children", treat barrenness in women and ease childbirth. This is the first phytochemical investigation of Brunsvigia natalensis, and yielded two new alkaloids, a new ceramide type compound and a known flavanoid. A comparative phytochemical investigation was carried out on the bulbs and seeds of Crinum stuhlmanni, which resulted in a number of different alkaloids being isolated from the seeds and bulbs of this plant. The southern African Hyacinthaceae is a large and chemically morphologically diverse group of plants. This family comprises approximately sixty-seven genera and nine hundred species worldwide, of which twenty-seven genera and three hundred and sixty - eight species are found locally. There are five sub-families of which three occur in southern Africa. The chemical constituents of this family can be divided into four classes, namely homoisoflavanones, steroidal compounds, bufadienolides and miscellaneous compounds. These plants are used in local traditional medicine for treating ailments such as hangovers, rheumatic fever, sprains and even cancer. The phytochemistry of three Hyacinthaceae plants was studied. The phytochemical investigation of Drimia macrocentra and Urginea riparia yielded a novel bufadienolide glycoside. These glycosides are quite unusual with the glycone attached to the aglycone at C-2 and C-3 and this has only been reported only once before in this family. The phytochemical investigation of Ledebouria revoluta yielded a number of homoisoflavanones. These homoisoflavanones have been shown to have anti-inflammatory activity and all of the compounds isolated in this work have been screened for this activity. Structural elucidation was carried out using spectroscopic methods such as NMR, MS, UV and IR.
Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2004.

Ledebouria zebrina and Scilla natalensis Planch were the two species investigated in this work. Ledebouria zebrina belongs to the Hyacinthaceae (Liliacea sensu lato) and to this date, the chemical composition of this species has not been investigated. Members of this family are found in southern Africa. The Ledebouria genus was formerly classified as part of the Scilla genus from which a large member of naturally occuring oxygen heterocycles known as homoisoflavanones have been isolated. In this work the bulbs of L. zebrina were investigated and five compounds were isolated. Three compounds were of the homoisoflavanone type while the remaining two belong to the eucosterol type triterpernoids. Scilla natalensis Planch also belongs to the Hyacinthaceae family. Previous chemical investigations of the bulbs of this plant yield two homoisoflavanones of the 3-benzyl-4- chromanone type. Members of this family are mostly found in the Eastern parts of the country, ranging from the Eastern Cape to Mpumalanga province including Lesotho and Swaziland. The bulbs of this plant were investigated and this yielded ten compounds. The structures of the isolated compounds were elucidated using spectroscopic methods.
Thesis (M.Sc.)-University of Natal, Durban, 2001.

Three species have been investigated in this project: Iso-ocobullenone (p 23) and its probable precursor (p 27) have been isolated from the leaves and bark of Ocotea kenyensis. This is only the second time that these compounds have been isolated and the first time from this species. The isolation of these two compounds in the leaves establishes a commercially important chemical link with the bark. The bark of the closely related Ocotea bullata is the most sought after source of "muthi" in the Kwa-Zulu Natal region and it is becoming a very scarce commodity. The leaves of Ocotea kenyensis have also yielded related compounds including A8'-3,5-dimethoxy-3',4'-methylenedioxy-l ',2',3',4'-tetrahydro-6' -oxo-7,1',8,3'-neolignan which is described here for the first time. Other compounds isolated were bacterialprenol, triacontane, B-sitosterol and a previously undescribed isoprenoid. An investigation into the molluscicidal potential of compounds in Apodytes dimidiata was extended with a view toward control of the population of the intermediary snail host for bilharzia-causing trypanosomes. This study afforded the known compounds squalene, lupeol, betulinic acid and catechin. The synthesis of a previously isolated compound, 4-ethyl catechol, with molluscicidal activity was successfully completed and its structure and activity were confirmed. A bio-assay guided isolation procedure was used to determine the potential value of compounds in Ehretia rigida for the control of sleeping sickness. Allantoin, a- and B-amyrin, triacontanol and B-sitosterol were isolated. Activity of the extracts was not high enough to be of commercial value.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998

碩士
中原大學
機械工程研究所
100
As the semiconductor manufacturing strides forward into the ULSI (Ultra-large-scale integration) fabrication and the competitors increase with similar technology and facilities, the semiconductor industry has become a highly standardized industry. However, the prices of semiconductor products dramatically decline because of outstripped supply from mass production. Therefore, the manufacturers must reduce their production cost in order to gain a profit. Stringent process control is the hinge. In most semiconductor companies, the development and adjustment of process recipes are based on either experience or method of trial and error, being a labor-intensive and time-consuming procedure. After the adjustment of process recipe, the trial productions are also required. For the automatic production in semiconductor industry, the requirement of manpower for process development and adjustment reduces manufacturer’s competitiveness. Chemical mechanical planarization (CMP) is a semiconductor manufacturing process using a lot of consumptive materials, such as polishing pad and slurry. This process is unstable due to drift characteristics. To effectively control this process and to avoid unexpected costs arising from defect products, Radial Basis Function Network (RBFN) and Taguchi genetic algorithm (TGA) was used in this study to analyze the process characteristics of CMP. By means of adjusting the process recipe, this proposed method can control the CMP process subject to disturbance and metrology delay. The process engineers can discover any abnormalities immediately from the polished products, without increasing equipment and manpower. Substantially, the scraps can be reduced. Moreover, it is also helpful for decreasing the burden of labors and promoting the product yield.

碩士
朝陽科技大學
環境工程與管理系碩士班
90
Sulfate-contained particulate dry depositions by observing the deposited particulate at traffic intersection, coastal, and suburban areas were investigated. The deposited samples were coated with barium chloride (BaCl2) in the vacuum evaporator an then exposed to a relative humidity of 85% for 2 hours to form distinctive products for sulfate-contained particulates. The samples were observed by scanning electron microscopy. The major results are as follows : 1. Average volume shape factor (Sv) value of total particulate at traffic intersection was significantly higher than those at coastal and suburban areas, which suggests that sulfate-contained particles at traffic intersections are more irregular. 2. Dry deposition fluxes estimated by mass of collected particulate divided by the collecting surface area and time were comparable to the values estimated by observing the deposited particulate. 3. The NMDs of sulfate-contained particulate were 0.407, 1.21, and 0.823 μm at traffic intersection, suburban, and coastal areas. Traffic intersection site had small NMD, which shows that most sulfate-contained deposited particulates existed in fine diameter range. The MMDs of sulfate-contained particulate were 8.78, 14.9, and 19.5 µm at traffic intersection, suburban, and coastal areas, which were much higher than NMDs. 4. Sulfate-contained particulates less than 10 μm contributed 28.6%, 7.08%, and 7.64% to total dry deposition at traffic intersection, suburban, and coastal areas, respectively. The contribution of fine particulate was significantly higher at traffic intersection site. 5. Average number of sulfate-contained particulate in total particulate 32.8%, 21.8%, and 33.2% at traffic intersection, suburban, and coastal areas. The percentage of sulfate-contained particulate was lowest at suburban area.

碩士
國立清華大學
化學工程學系
91
The synthesis of both nanosized palladium-silver and silver colloids by chemical reduction using formaldehyde was investigated in this thesis. The effect of polyvinylpyrrolidone (PVP) on the precipitation mechanism was specifically studied. It was found that due to the strong interaction between Pd ions and PVP molecules, the Pd content in the co-precipitated products would be less than corresponding ones obtained in the absence of PVP molecules. This method could produce palladium-silver alloy colloids of 2~3 nm with a Pd rich core. Increasing PVP quantity would increase the palladium-silver alloy particles, and also make the size distribution much broader. Polyvinyl pyrrolidone (PVP) of three different molecular weights (MW = 8,000, 29,000, 55,000) were studied in this thesis on their ability to stabilize silver colloids. Our results indicated that their effects against agglomeration would depend to a great extent on the alkaline used for the promotion of reduction reaction at ambient temperature. When NaOH was used, the reaction rate was very fast and hence only PVP with large molecular weight could produce silver colloids of sizes around 20 nm. On the other hand, when Na2CO3 was used, the reaction path was significantly changed and slowed down as well. Under this circumstance, PVP with MW of 8,000 offered the best protection against agglomeration. It could produce silver colloids of only 5 nm and the size distribution was nearly uni-modal. Increasing PVP quantity had only slight effect on silver size. In addition, the sintering behavior was also briefly studied for these nanosized palladium-silver alloy and silver colloids.

碩士
國立中央大學
應用地質研究所
100
Global energy demand for the development and utilization of new alternative energy is increasing for a long time, in which CBM (Coal Bed Methane) is one of the popular research topics in recent years. The purpose of this study is to perform a series of physical and chemical characteristic studies of coal, so as to understand the relation between coal properties and gas adsorption storage. Permian coals from Bowen and Sydney Basin, Australia, were examined in this study. The results showed that vitrinite reflectance is ranged 0.54~1.03%, composed mostly of vitrinite, and classified as immatured to matured high volatile bituminous coal. Langmuir adsorption isotherm indicates B2 from Bowen Basin possesses the highest adsorption capacity, where as S1 and S2 from Sydney Basin exhibit the lowest adsorption capacity. The difference in adsorption isotherm is mainly controlled by surface area and volume of pores. Both secondary porosity and pore volume increased with cleats and fractures developed after coalification. The influence of maceral composition is relatively less important. Most of the permeability of coal is low in samples studied, except B3 coal exhibits the highest permeability and porosity, which can be attributed to well developed and connected fractures. B3 is believed to be the most promising target for gas sequestration.

碩士
國立宜蘭大學
食品科學系碩士班
101
Acorns, the seeds of Fagaceae plants, are important forestry resources in Europe and Asia. In Taiwan, there were at least 50 edemic of Fagaceae in temperate and subtropical mountain forest Association. The acorns of Fagaceae are valuable food for wild life and human nutrition. In this study, the effect of drying conditions (dried at room temperature, dried at freeze, dried at 40℃, 60℃) on morphological and chemical properties of (Cyclobalanopsis glauca, CG; Lithocarpus lepidocarpus, LL; Castanea mollissima, CM) nuts flours were evaluated. Flours produced by milling seed dried at different condition were evaluated for flour color, starch granules morphology, amylase and amylopectin content, antioxidative antioxidants, solubility, swelling and cookier products. The data showed that acorns starchs granul morphology were rounded and polygonal. The acorn flours color (L*, a*, b*) generally decreased with increasing drying temperature. The color of CG flour presented yellowish, LL flour presented reddish, and CM flour presented white color. Antioxidant activity of the sample were assayed through FRAP (Ferric Reducing Antioxidant power), DPPH (1,1-diphenyl-2-picrylhydrazil) radical scavenging activity test and TEAC (Trolox equivalent antioxidant capacity). Methanol extracts of dried at room temperature, thermally treated and freeze dried acorn flours showed the high antioxidant activity, with extracts of thermally treated acorn flours being more active than extracted of dried at room temperature. The methanol extract of LL flours showed the highest antioxidant activity among the acorn flours, these activities were correlated with phenolics contents. The cookier that added 30% acorn flours had much more crude fiber and resistant starch than wheat cookier. As the results, thermally treated acorn flours possess higher antioxidant activity than do the dried at room temperature. The obtained results have provided forth grounds for establishing GC, LL, CM acorn flours as a source for functional food preparation.

碩士
國立中央大學
環境工程研究所
107
Urban wastewater treatment plants (UWTPs) could be an emission source of bioaerosols and particle matters into the air through the air-liquid exchange process and bubble-jet-droplet mechanism. It poses the potential of spreading human opportunistic pathogen and pharmaceutical emerging pollutants in wastewater into the air. In view of the potentials of emission and exposure risks of airborne particles in UWTPs, there is a need to comprehensively characterize the physical, biological and chemical characteristics of particles emitted from UWTPs. The main objective of this study is to characterize the wide-size-range particle size distribution (PSD) and the characteristics of bio-aerosols generated in a UWTP. In addition, the ultraviolet aerodynamic particle sizer (UV-APS; model 3314; TSI, USA) was used to detect viable bio-aerosols in real time. Meanwhile, the air samples were also collected by high-volume samplers (HV-RW; model 080130-1203; SIBATA, Japan) for investigating the occurrence and the distribution of emerging pollutants on the particles emitted from the aeration tank. The measurements were conducted at two sampling ports in a UWTP located in northern Taiwan. One is 1 meter away from aeration tank (AM), and the other is close to the water surface of the tank (CAT). On the number-based, the full particle size distribution exhibits a unimodal distribution and dominated by nanoparticles, which is accounted for about 99% of the whole PSD. On the volume-based, the distribution exhibits dual peaks and the modes of particle size are located at 0.5-0.7 μm and 2-3 μm. For the results of the biological characteristics revealed by UV-APS, the peaks of the fluorescent signal were sitting around 2-3 μm, implying that the most of fluorescence particles may be bacteria aggregates or fungal species. In addition, the concentration of the bio-aerosols in the UWTPs may be underestimated by the traditional cultivating method. Moreover, pharmaceuticals and emerging pollutants can also be transferred into the air. Nine common emerging contaminants, including PFOS, Benzotriazole, Tolyltriazole, Pentoxifylline, Erythromycin-H2O, Clarithromycin, Ketamine, Methamphetamine, PFOA were analyzed and found in both air and water samples. Among them, the most abundant chemicals in the air are Erythromycin-H2O (191.45 pg/m3) and Methamphetamine (39.02 pg/m3) and mainly reside on PM1.0.

碩士
國立交通大學
機械工程系所
106
Thin-shell injection-molded products have been widely used in consumer electronics market. Product design becomes more complex as this market grows. To enhance yield rate and product quality, manufacturers commonly use high-speed injection-molding machines. However, such machines may cause high residual stress and shear heating during the molding process, which deteriorates product quality. In addition, high-speed injection molding machines and their molds cost much more than the traditional injection-molding machines. In this study, we added a chemical foaming agent (CFA) into plastic pellets during the injection-molding process of thin-shell parts. The variation in polymer rheological properties was characterized to investigate the effect of CFA on thin-shell molding product quality such as shrinkage and surface defect. An endothermic CFA was added into polycarbonate (PC) and its blend with polycarbonate acrylonitrile butadiene styrene (ABS) separately in this research. Taguchi method and analysis of variance were employed to discuss the effect of process parameters and appending proportions on product quality. The results showed that the addition of appropriate proportion of CFA reduced the shrinkage of PC thin-shell parts at far gate side and improved differential shrinkage. Moreover, CFA eliminated the local shrinkage hole on surface, indicating a great improvement in surface quality. In PC/ ABS blend, the addition of CFA did not have a statistically significant effect on both overall shrinkage and differential shrinkage. Endothermic CFA can be used to reduce PC part shrinkage, eliminate differential shrinkage, and promote surface quality. Such features can make great contribution to advancing the quality of injection-molded thin-shell products.

The Forensic Chemistry Laboratory of Johannesburg (FCL JHB) is tasked with the chemical analysis of a variety of samples to assist in determining the cause of death where unnatural cause is suspected. Some of the samples submitted to the laboratory have a herbal or muti connotation, but a large portion of these cases turn out to have no herbal components present as only pharmaceutical or agricultural products are detected in these samples. This study combined, for the first time, forensic investigation, chemistry and botany to create a unique platform needed for the identification of poisonous plants and their components in forensic exhibits and viscera. The research was focussed on the poisonous plants previously detected at the laboratory, as well as the requests received for the analysis of muti/toxic plant components. The selection of plants included Nicotiana glauca, Datura stramonium / Datura ferox, Callilepis laureola, Boophone disticha / Ammocharis coranica, Abrus precatorius, Ricinus communis, Nerium oleander / Thevetia peruviana and Bowiea volubilis. All these species are known to have caused fatalities, hence their choice. Nicotiana glauca has been implicated in the deaths of at least 15 people since 2001. It was previously detected by GC-MS (EI) in plant exhibits, but could not be detected in a viscera matrix. A selective extraction method for alkaloids was used to extract botanical and viscera samples. Anabasine was successfully detected on the HPLC-MS (EI) system but this detection technique was not considered sensitive enough. A very sensitive HPLC-MS method was developed on the ZMD detector by using electrospray technology. This method outperformed both electron impact detectors (GC and HPLC) and could detect 1ng/ml anabasine with relative ease in full scan mode. Datura stramonium and D. ferox have not been previously positively linked to any human poisoning or death due to exposure to botanically derived products at the FCL JHB. Atropine and scopolamine were successfully ionised in ESI positive mode and could be detected at 10 pg/ml and 100 pg/ml level respectively. The identities of the compounds were confirmed by characteristic ISCID fragmentation patterns. The developed method was successfully applied to a suspected heart attack case. The results proved conclusively that the deceased was given D. ferox seeds as part of his meal and an overdose of atropine and scopolamine contributed to his death. Callilepis laureola is reputed to be one of the more commonly used medicinal plants in South Africa, and although its use has been indicated by the specific mention of a possible nephrotoxin and/or hepatotoxin as causative agent, it has not been detected in any of the forensic chemistry laboratories in South Africa. This was mainly due to the absence of a reliable method for the analysis of the main toxic component of C. laureola, atractyloside, by mass spectrometry. A sensitive and very selective HPLC-ESI-MS method was developed that could detect atractyloside, carboxyatractyloside and their monodesulfated analogues in botanical and viscera matrices. The method was successfully applied to a variety of forensic samples and proved that C. laureola may play an important role in herbal poisonings. In a selection of suspected herbal poisonings where the cause of poisoning was unknown, 30% of the samples tested positive for the presence of atractyloside, carboxyatractyloside or their monodesulfated analogues. The bulbs of Boophone disticha are rich in isoquinoline alkaloids and some of the alkaloids were detected by GC-EI-MS and LC-EI-MS, but the detection of these alkaloids in viscera samples was not successful. A routine method used for the screening for drugs of abuse in forensic samples, were successfully used for the analysis of the bulb extracts of B. disticha and the bulb scales of A. coranica. The chromatographic profile of these two plants appeared very similar at a first glance, but a closer evaluation of the mass spectra highlighted significant differences between the two plants. Six alkaloids from B. disticha were isolated and characterised by LC-MS and NMR and these compounds were detected in suspected herbal poisoning cases. It has been shown that B. disticha is one of the commonly used plants to “clean the system” but frequently results in the death of the patient. Abrus precatorius contains one of the most toxic compounds known to mankind, namely abrin that collectively refers to a group of glycoproteins. The seeds of A. precatorius also contain two indole alkaloids, abrine and hypaphorine. The two alkaloids were fractionated and characterised by LC-MS and NMR. Due to the fact that the instrumentation of the FCL JHB is not suited to the detection of proteins, an LC-ESI-MS method was developed for the detection of the two alkaloids in plant and viscera matrix as markers for A. precatorius. The presence of these two alkaloids was indicated on the TMD system (EI spectra) in a suspected herbal poisoning case. The LC-ESI-MS method was applied to the analysis of the samples and the absence of abrine and hypaphorine were proven in the samples. Ricinus communis is similar to A. precatorius in that it also contains a group of extremely poisonous glycoproteins, collectively refered to as ricin. The analysis of R. communis seeds encountered the same problems as the analysis of A. precatorius seeds, and the analysis was again focused on the detection of the minor piperidine alkaloid ricinine. The LC-ESI-MS method developed for abrine was modified to detect ricinine and functioned well in botanical and viscera matrices. This method will enable the forensic analyst to detect ricinine in very low levels when the presence of ricinoleic acid in samples indicates the use of a R. communis-based product. Nerium oleander is a common decorative garden plant that is used medicinally. The plant is rich in cardenolides with oleandrin the main compound. A reversed-phase chromatographic method with ESI mass spectral detection was developed to separate and detect 11 cardiac glycosides. The compounds were adequately separated to allow unambiguous identification, and displayed very stable cationisation with sodium. An extraction method was developed to extract the cardiac glycosides from the leaves of N. oleander and Thevetia peruviana and was also evaluated in a viscera matrix. The extraction method functioned well and extracted a variety of compounds that produced unique chromatographic fingerprints, allowing for the easy differentiation between the two plants. The method is ideally suited for the detection of oleandrin in high concentrations (full scan mode), low concentrations (selected masses) or trace levels (SIM analysis of ion clusters). The method is able to distinguish between extracts derived from N. oleander and T. peruviana and was able to detect and confirm neriifolin, odoroside and neritaloside in N. oleander leaf extracts. Analysis of forensic case exhibits were also successfully done with this method and performed well with liquid and solid matrices. With the new method oleandrin could be detected at trace levels in viscera samples that did not produce positive results in the past. Bowiea volubilis is widely used as a medicinal plant, but is also an extremely toxic plant. It is freely available at traditional healer markets, and is one of the most highly traded plants on the Durban market. Despite the high usage of the plant, it has not been detected by any of the forensic laboratories in South Africa. Bovoside A, a bufadienolide, is reported to be the main cardiac glycoside in the bulb of B. volubilis. The cardiac glycoside method was successfully applied to the analysis of the bulb extract of B. volubilis and bovoside A was identified as the main bufadienolide present in the bulb. Bovoside A was fractionated and characterised by LC-MS. Four extracts of botanical origin could be successfully distinguished from each other by monitoring the main masses of bovoside A, oleandrin and thevetin A and thevetin B. These marker compounds were well separated from each other and made the identification of the botanical extracts quite easy, and the identity of each extract was confirmed by the mass spectrum of each peak.
Prof. F.R van Heerden

Momordica foetida Schum. & Sond. (Cucurbitaceae), locally known as iNtshungu, is widely used by the Zulu people of Natal-KwaZulu for the treatment of a variety of ailments. The dried leaves leaves and stems of this plant was subjected to soxhlet extraction by refluxing with hexane, chloroform and methanol successively. Thin layer chromatography of the chloroform extract of the leaves revealed a multiplicity of compounds. The chloroform extract was further partitioned with sodium hydroxide resulting in an organic and aqueous phase. The organic phase, containing extract A, afforded two compounds, viz. compounds 1 and 2. The basic aqueous fraction was neutralised and re-extracted with chloroform to give extract B, affording five compounds, viz. compounds 3,4,5,6 and 7. Structural elucidation was accomplished by techniques such as IH and 13C NMR spectroscopy, HETCOR, COSY, FTIR and High Resolution Mass Spectrometry. Compounds 1 and 2 were identified as cucurbitane triterpenoids known as momordicines which had been previously discovered in the related species of this plant, Momordica charantia L. The remaining five compounds were identified as novel compounds, although natural derivatives of compounds 6 and 7 had been isolated previously from Momordica charantia L. Compounds 3-7 were each isolated as an epimeric mixture but it was possible to select the resonances corresponding to the major epimer. These five epimers were respectively identified as 5, 19-epoxy-19(R)-hydroxy-25-methoxy-5β- cucurbita-6,23-diene-3β-ol [102], 5,19-epoxy-19(R),25-dihydroxy-5β-cucurbita- 6,23-diene-3β-ol [103], 5,19-epoxy-19(R)-methoxy-25-hydroxy-5β-cucrbita- 6,23-diene-3β-ol [104], 5,19-epoxy-25-methoxy-5β-cucurbita-6,23diene- 3β-ol [105] and 5,19-epoxy-19(R),25-dimethoxy-5β-cucurbita-6,23diene- 3β-ol [106]. Appropriate reactions were performed, where possible, on the compounds isolated in order to confirm their identity.
Thesis (M.Sc.)-University of Natal, Durban, 1994.

Ledebouria ovatifolia (Bak.) lessop, Clivia caulescens R.A.Dyer and Haemanthus pauculifolius Snijman & Van Wyk were the three species investigated in this work. Ledebouria ovatifolia belongs to the family Hyacinthaceae (Liliaceae sensu lato) and, to date, the chemical composition of this species has not been investigated. Members of this family are widely distributed, but are particularly well represented in Southern Africa. The Ledebouria genus was formerly classified as part of the Scilla genus from which a large number of naturally occurring oxygen heterocycles known as homoisoflavonoids have been isolated. In this work the bulbs of L. ovatifolia were investigated and two compounds were isolated. These were the homoisoflavonoid, 5,7-dihydroxy-3-(4'-hydroxybenzyl)-4-chromanone and the chalcone, 6',2'-dimethoxy-4,4'dihydroxychalcone, both of which are known naturally occurring compounds. Clivia caulescens and Haemanthus pauculifolius are both members of the Amaryllidaceae family. The plants of the Amaryllidaceae family form a large group of over sixty genera, which are concentrated mainly in Southern Africa. Plants from this family have been extensively used in traditional medicines and many have pharmacological properties. The compounds responsible for most of these effects are a group of isoquinoline alkaloids, which are found almost exclusively in plants belonging to this family. The alkaloids isolated from plants belonging to this group are known to cause poisoning in low doses and can cause excessive salivation and diarrhoea. Higher doses of the active compounds can cause CNS depression and large enough doses can prove fatal. Although many of these alkaloids are harmful to man, some of the unique Amaryllidaceae alkaloids exhibit anti-tumour and anti-viral activities, and are thus potentially beneficial to man. The Clivia genus is endemic to South Africa and the most common species, C. miniata, is used by traditional healers to facilitate childbirth and as a snake bite remedy. In this chemical investigation both the bulbs and the leaves of C. caulescens were investigated. The ethanol extract of the bulbs yielded four alkaloids, hippeastrine, haemanthamine, lycorine and ll-(S)-hydroxyvittatine. The investigation of the leaf extract also yielded lycorine and hippeastrine as well as an additional alkaloid sternbergine. Haemanthus pauculifilius is a recently described member of the Haemanthus genus, which consists of 27 taxa that are restricted to Southern Africa and Namibia. In this chemical investigation the ethanol extract of the bulbs and leaves yielded the common triterpenoid sitosterol as well as two novel 5,11-methanomorphanthridine type alkaloids, montanine hydrochloride and manthidine.
Thesis (M.Sc.)-University of Natal, Durban, 1999.

This study was undertaken to redress the scant knowledge regarding the chemistry and mode of action of pregnancy-related traditional medicines, or isihlambezo (Zulu), which are used by 60 to 80% of women in South Africa. The three selected plants are among the six most frequently cited species from the approximately 90 used by traditional healers. The purpose of the study was to identify components which could cause uterine contractions, those with nutritional value for the foetus and mother, and those with any toxic effects. Plant root extracts were purified via silica gel column chromatography and bioassays were carried out on the fractions, using isolated rat uterine tissue. Purified compounds were identified via spectral techniques, and some were characterised by comparison to authentic standards using HPLC, and others by matching their GC-MS spectra to library standards. Thirty-eight compounds were identified in total, the majority of these being novel to the species concerned. Those isolated from Combretum kraussii were 1 sitosterol, 2 combretastatin, 3 3',4-tri-O-methylellagic acid, 4 combretastatin B-1, 5 combretastatin A-1, 6 3,3'-di-O-ellagic acid lactone, 7a ellagic acid lactone, 7b ellagic acid, 8 and 9 a mixture of combretastatin B-1 and A-1 glucosides, 10 and 11 partly characterised glucosides of ellagic acid. Those isolated from Gunnera perpensa were 12 3',4-tri-methylellagic acid, 13 ellagic acid lactone, 14 1,1'-biphenyl-4,4'-diacetic acid, 15 p-hydroxybenzaldehyde, 16 Z-methyl lespedezate, 17 and 18 partly characterized higher glucosides of Z-methyllespedezate. Those isolated rom Rhoicissus tridentata were 19 (-)-epigallocatechin, 20 (+)-gallocatechin, 21 procyanidin B3, 22 procyanidin B4, 23 (+)-catechin hydrate, 24 (+)-mollisacacidin, 25 (+)-epicatechin, 26 fisetinidol-(4a-8) catechin, 27 (-)-fisetinidol, 28 fisetinidol-(4b-8)catechin, 29 gallic acid, 30 epicatechin-3-0-gallate, 31 partly characterized hydrogel of glucose, 32 sitosterol, 33 sitosterolin, 34 y-sitosterol, 35 oleanolic acid, 36 lupen-3-one, 37 20-epi-y-taraxastananol and 38 triacontanol. The compounds with the greatest in vitro uteroactivity were predominantly proanthocyanidins or phenolic glucosides. It is proposed that effects of phenolic glucosides could be due to the interaction of the sugar moiety as well as the phenolic moiety with the receptor site in muscle tissue. The corresponding phenolic aglycones isolated were only moderately uterotonic, or unreactive by comparison. Non-polar compounds such as sitosterol and sitosterolin showed minimal enhancement of the uterine response at low concentrations, and inhibition at higher concentrations. Aqueous root extracts of the plants were all found to be non-toxic according to cell-viability tests using monkey vero cells and human fibroblasts. Extracts are therefore considered safe for human consumption, although it is recommended that Rhoicissus tridentata be used with caution because it showed the lowest cell viability of the three species, and uterine hyperstimulation has been attributed to this species, as well as CNS depression and respiratory arrest. Ions which could be nutritionally beneficial in pregnancy, calcium, iron, and phospate, were present in low in aqueous extracts. Levels of calcium and potassium ions were considered to be too low to directly stimulate uterine muscle. Proanthocyanidins, combretastatins, ellagic acid derivatives and phytosterols, with health-promoting properties, were also identified.
Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2004.

碩士
逢甲大學
化學工程學所
98
Polyimides (PIs) with different inclination angle of polymer backbones, together with polar hydroxyl group and/or nonpolar trifluoromethyl group at various sites of the backbone were synthesized and used as liquid crystal alignment layers. The molecular conformation, surface chemistry, surface energy, surface morphology, and pretilt angle of the PI film were investigated. Effects of the conformation of the PI molecular backbone and the surface morphology of the rubbed PI layer,together with the intermolecular interaction between the LC molecular and the PI film on the pretilt angle and surface energy of the alignment film were studied. The distributions of fluorinated group and hydroxyl group at different depths of the PI surfaces were analyzed by X-ray photoelectron spectroscopy. The PI containing both nonpolar fluorinated groups sticking out of the PI surface and the polar hydroxyl group on the surface leads to high pretilt angle.

碩士
崑山科技大學
光電工程研究所
98
In this thesis, the CdS buffer layer of CuInSe2 (CIS) thin film solar cell is fabricated by Chemial Bath Deposition （CBD）and Sputtering Deposition (SD) methods, respectively. And there are two kinds of CBD methods, they are Co-melting CBD method and Separate-melting CBD method, respectively. The Co-melting CBD solution is completed with ammonium sulfate, cadmium sulfate, thiourea and ammonia melting together into 400 ml deionized water. For the Separate-melting CBD solution, firstly ammonium sulfate and mole cadmium sulfate melting separately into 50 ml deionized water, respectively; and thiourea and ammonia are mixed together; then the above three solutions are poured into 300 ml deionized water to become the final solution. The reason of adopting the CdS thin film as the buffer layer of CIS thin film solar cell is that the CdS can play as energy gap buffer and reduce the band-offset between CIS absorbing layer and the Transparent Conductive Oxide (TCO) layer. The CdS thin films are generated by above two kinds of CBD methods in situation of atmosphere. And the CdS thin film generated by SD method is in situation of 3.7 mtorr vacuum pressure. In order to analyze the characteristics of the CdS thin films conveniently, the CdS thin films are firstly fabricated on Soda-lime, and the final found optimal CdS thin film is fabricated on the CIS/Mo/Soda-lime. Then the p-n diode characteristic of the CdS/CIS/Mo/Soda-lime is measured by four-point probe. The CdS thin film obtained by SD method is adopted RF power with range from 200 W to 500W. It is found by analysis that 500 W is the optimal RF power; more uniform thickness of CdS thin film can be obtained and its thickness is easier to control. And the CdS thin films are fabricated by the above two kinds of CBD methods through various combinations of time interval from 20 to 60 minutes and temperature range from 70 ℃ to 85 ℃. It is found that the 80 ℃ and 60 minutes is the optimal combination; the smoother surface and more uniform thickness of Separate-melting CBD CdS thin film can be obtained. And it is found from optical characteristic analysis that in situation of emitted light wave length 500nm, the transmittance of the Separate-melting CBD CdS thin film is 61%, and it is better than that of SD CdS thin film with 56%. Meanwhile, the band gap of Separate-melting CBD CdS thin film is close to theoretical value of 2.4 eV. Then the Separate-melting CBD and SD CdS thin films are stacked on the CuInSe2/Mo/Soda-lime, respectively. It is shown that the p-n diode characteristic curve of the Separate-melting CBD CdS/CIS/Mo/Soda-lime is better than that of the SD CdS/CIS/Mo/Soda-lime. Thus, it is proved that the Separate-melting CBD method can obtained a better CdS thin film.

碩士
國立交通大學
電子工程系
89
Abstract It is an inevitable trend for the gate dielectric to fabricate the ultrathin oxide in the future ULSI applications. However, it is difficult to fabricate the ultrathin gate oxide about 2nm in a stable and good environment. In spite of success of it, the boron atoms will penetrate into the thin oxide easily and lead to the reliability problem because the thickness of the oxide is too thin and boron is one kind of active atoms. In order to overcome its reliability problem, we use a new method to fabricate a better gate oxide. First, we grow a chemical oxide before the dry oxidation is put into practice. Second, it will be nitridized in the pure ammonia gas. Finally, the ultra-thin gate oxynitride is finished after the dry oxidation is carried out. The chemical oxide and the nitrogen that piles up at the top of the oxide bulk and at the interface between the silicon and the gate oxide will improve the I-V characteristic and C-V characteristic. We will know that the leakage current will be lower and the boron penetration will be suppressed in out studies. Therefore, it is practicable for our ultra-thin oxynitride if the device is scaled down. In the meanwhile, it can also be predicted that it can be applied to the high-K materials.

Tese de mestrado, Ciências Biofarmacêuticas, Universidade de Lisboa, Faculdade de Farmácia, 2017
Espécies do género Hypericum L. (Hypericaceae Juss.) têm sido utilizadas em todo o mundo como medicamentos tradicionais contra um grande número de patologias. Existem cerca de 500 espécies deste género botânico. Vários estudos de atividade antitumoral envolvendo diferentes espécies foram já realizados e mostraram a atividade antitumoral in vitro de diferentes espécies deste género botânico Hypericum, tais como Hypericum perforatum e Hypericum androsaemum. Este facto, associado à inexistência deste tipo de estudos, relativamente a Hypericum foliosum, uma espécie cuja parte aérea é usada na medicina tradicional nos Açores, Portugal, para o tratamento de infeções virais e problemas cutâneos, leva a que se considere o estudo desta planta medicinal como promissora e que seja o objeto de estudo do presente trabalho. Para determinar o potencial anticancerígeno in vitro, foram usados três extratos de diferentes polaridades de H. foliosum, parte aérea (lipofílicos: Hf.E, Hf.DM e hidrófilo: Hf.W) e três linhas celulares de cancro humano (do cólon, do pulmão e da mama). Atendendo a que sobre a parte aérea de H. foliosum, os elementos monográficos de qualidade necessários à sua correta caracterização, enquanto possível substância derivada de plantas, passível de sua utilização como matéria-prima para produção de produtos de saúde à base de plantas são escassos ou inexistentes, o presente trabalho contempla a identificação botânica da amostra de H. foliosum, parte aérea em estudo, de acordo com as especificações usuais da Farmacopeia Europeia, que incluem a caracterização macroscópica e microscópica da amostra fragmentada e pulverizada. A descrição morfológica e os dados microscópicos qualitativos e quantitativos obtidos permitiram o estabelecimento dos critérios de identificação essenciais para a análise de H. foliosum como matéria-prima para uso industrial, incluindo produtos farmacêuticos, recomendando-se assim, que os critérios agora definidos sejam intergrados numa futura monografia de qualidade oficial desta planta medicinal. Após caracterização botânica, as amostras de H. foliosum, parte aérea foram também objeto de caracterização química por TLC e por quantificação dos principais grupos de metabólitos secundários detetados. Atendendo à estreita correlação entre a atividade antioxidante, captador de radicais livres e o potencial quimioprevenção de algumas espécies botânicas e classes de metabólitos secundários que as constituem (i.e. flavonóides, fenilpropanoides, floroglucinóis) e ao facto de que H. foliosum, parte aérea terem sido já descritas por outros autores o potencial antioxidante e antiradical dos três extratos de H. foliosum em estudo foi também determinado. Os resultados do trabalho químico desenvolvido para estabelecer o perfil cromatográfico dos três extratos de H. foliosum (Hf.E, Hf.DM e Hf.W) e quantificar as principais classes de compostos marcadores presentes permitiram verificar ser o extrato etanólico (Hf.E) o de maior diversidade química. Este extrato mostrou também conter o teor máximo de compostos fenólicos totais (148,91 ± 0,71 mg GAE/g dE), flavonóides (144,66 ± 1,44 mg CE/g dE) e de taninos condensados (1356,10 ± 33,36 mg CE/g dE), enquanto o extrato de DCM-MeOH mostrou ser o mais rico em triterpenoides (721,47 ± 12,05 mg de OAE/g dE) e taninos hidrolisáveis (514,79 ± 81,88 mg GAE/g dE). A atividade antioxidante foi avaliada em termos de atividade antiradical, capacidade redutora e atividade antioxidante total. Mostrou ser o extrato Hf.E o de maior atividade antiradical (IC50 = 490,51 μg/mL) e o de maior potência redutora, enquanto que Hf.DM mostrou um forte efeito contra a atividade antioxidante total (IC50 = 154,74 μg/mL). Foram observadas correlações significativas entre os resultados do teste TPC e DPPH, confirmando o papel dos compostos fenólicos na inibição de radicais livres e catiões radicais nesses sistemas; enquanto os taninos hidrolisáveis e as triterpenoides desempenharam um papel fundamental em relação à atividade antioxidante total. Os resultados dos ensaios de citotoxicidade in vitro usando o ensaio MTT, mostraram a significativa atividade dos extratos Hf.E e em especial Hf.DM contra as três linhas celulares tumorais ultilizadas, sendo as concentrações inibitórias de 50% da polulação celular do extrato (IC50) Hf.E de 108.58 μg/mL em células tumorais MDA-MB-231 (da Mama), de 76.30 μg/mL em células tumorais A549 (do pulmão) e de 119.93 μg/mL em células tumorais HCT 8 (do cólon). Respetivamente, Hf.DM mostrou uma IC50 de 71.49 μg/mL em células tumorais MDA-MB-231, de 27.31 μg/mL em células tumorais A549 e de 9.51 μg/mL em células tumorais HCT 8. Hf.DM mostrou assim uma influência significativa sobre o crescimento celular de células tumorais do cólon (HCT 8). Tanto quanto é do nosso conhecimento, é pela primeira vez demonstrado o potencial antitumoral de H. foliosum em extratos totais de diferentes polaridades no carcinoma de mama, pulmão e cólon, tendo sido caracterizados quimicamente, quanto à classe de compostos maioritários presentes e respetivo teor e sua correlação com a atividade quimioprotetora também por nós demonstrada. Todos os estudos biológicos foram realizados em matéria-prima caracterizada ao nível botânico e químico de acordo com as especificações em vigor para fármacos vegetais, o que é também uma característica inédita deste trabalho. Como conclusão, H. foliosum parece ser um bom candidato como fonte de compostos com atividade anticancerígena para estudo futuro.
Species of the genus Hypericum L. (Hypericaceae Juss.) have been used worldwide as traditional herbal medicine against a multitude of diseases. There are about 500 species in the Hypericum genus. Concerning that many studies related to other species of the same genus, such as Hypericum perforatum and Hypericum androsaemum, have been conducted and demonstrated anticancer activity in vitro and in vivo, but there is no related report on Hypericum foliosum, of which aerial part is used as traditional medicine in the Azores, Portugal, for the treatment of viral infections and cutaneous problems. This fact leads to consideration of this medicinal plant as a potential source of anticancer agents and that is the object of this thesis. Considering numerous botanical characterization of diverse Hypericum taxa, along with the great potential pharmacological development, literature references describing anatomical and histological features of H. foliosum as a herbal medicine for human use are scarce or non-existent. This fact requires urgent the establishment of adequate morphological characters concerning H. foliosum aerial part identification in order to allow the systematic studies of its potential as new medicine. As for this reason, one of the aims of the present study is establishment of macroscopical and microscopical morphological characterization of the dried whole, fragmented, and powdered aerial part, using with referential parameters for quality control, in accordance with official quality monograph specifications. Besides, according to a comprehensive bibliographical review on Hypericum species, we emphasis on the compounds derived from caffeoylquinic acid (e.g. chlorogenic acid) and phloroglucinols of Hypericum species, which are essential constituents of this genus with the higher potential anticancer activity. Therefore, in this project, we have a strong scientific interest in studying in vitro anticancer potential associated with three H. foliosum aerial part extracts (lipophilic: Hf.E, Hf.DM and hydrophilic: Hf.W) standardized by its chromatographic TLC fingerprint, quantification of the main chemical classes and the antioxidant properties. To determinate the in vitro anticancer potential of Hypericum foliosum extracts, we used three human cancer cell lines (colon, lung and breast), with objectives of establishing identification criteria and production standards, and verifying the in vitro anticancer potential of this medical plant as a source of anticancer agents. Botanical characterization was compiled by macroscopic and microscopic analysis of stem, leaf and powdered flowering aerial parts of H. foliosum. Morphological description and quantitative data extended the botanical foundation of H. foliosum as a raw material for industrial use, including pharmaceuticals. These results established criteria for identification of the dry aerial parts of H. foliosum, which can be applied in a future pharmacopoeial monograph as traditional medicine in Portugal. After botanical characterization, the chemical work was developed to establish the chromatographic profiles of three H. foliosum extracts (Hf.E, Hf.DM and Hf.W) and the main phytochemical compounds. From the studies of the phytochemical quantification of H. foliosum extracts, we can confirm that solvent choice influences the compositions of H. foliosum extracts. In fact, the maximum content of total phenolics (148.91 ± 0.71 mg GAE/g dE), flavonoids (144.66 ± 1.44 mg CE/g dE) and especially, condensed tannins (1356.10 ± 33.36 mg CE/g dE) were recorded in the 70% ethanol extract (Hf.E), while on DCM-MeOH extract (Hf.DM) more triterpenoids (721.47 ± 12.05 mg OAE/g dE) and hydrolysable tannins (514.79 ± 81.88 mg GAE/g dE) were detected. Antioxidant activities were evaluated in terms of antiradical activity, reducing power, and total antioxidant activity. Hf.E has more antiradical activity (IC50 = 490.51 μg/mL) and a little higher reducing potency, whereas Hf.DM showed a strong effect against total antioxidant activity (IC50 =154.74 μg/mL). Significant correlations were observed between the results of TPC and DPPH test, confirming the specific role of phenolic compounds in inhibiting free radicals and radical cations under these systems; while hydrolyzable tannins and triterpenoids played a pivotal role in relation to the total antioxidant activity. The results of the in vitro cytotoxicity by MTT assay showed the significant activity of Hf.E extracts and in particular Hf.DM against the three cancer cell lines used, the inhibitory concentrations (IC50) of Hf.E is 108.58 μg / mL on MDA-MB-231 (breast) tumor cells, 76.30 μg / mL on A549 (lung) tumor cells and 119.93 μg / mL on HCT 8 (colon) tumor cells. Respectively, Hf.DM showed an IC50 of 71.49 μg / mL on MDA-MB-231 tumor cells, 27.31 μg / mL on A549 tumor cells and 9.51 μg / mL on HCT 8 tumor cells. Hf.DM thus showed an influence of significant effect on cell growth of colon tumor cells (HCT 8). This thesis demonstrated that H. foliosum extracts had significantly different bioactive compounds and the results of MTT indicate that Hf.DM revealed a high level of biological anticancer activity in vitro. As far as we know, this is the first report of the anticancer potential of H. foliosum in total extracts of different polarity on breast, lung and colon carcinomas, combining chemically characterized the class of major compounds and their content and correlation with the chemoprotective antioxidant activity demonstrated by us. All the biological studies were carried out on botanical and chemical raw material according to the official specifications for medicinal plants, which is also an unpublished feature of this work. As conclusion, H. foliosum seems to be a good candidate as a source of compounds with anticancer activity for future study.

Deep geological repository (DGR) for disposal of high-level radioactive waste (HLW) is designed to rely on successive superimposed barrier systems to isolate the waste from the biosphere. This multiple barrier system comprises the natural geological barrier provided by the repository host rock and its surrounding and an engineered barrier system (EBS). The EBS represents the synthetic, engineered materials placed within the natural barrier, comprising array of components such as waste form, waste canisters, buffer materials, backfill and seals. The buffer will enclose the waste canisters from all directions and act as a barrier between canisters and host rock of the repository. It is designed to stabilise the evolving thermo-hydro-mechanical-chemical stresses in the repository over a long period (nearly 1000 years) to retard radionuclides from reaching biosphere. Bentonite clay or bentonite-sand mix have been chosen as buffer materials in EBS design in various countries pursuing deep geological repository method. The bentonite buffer is the most important barrier among the other EBS components for a geological repository. The safety of repository depends to a large extent on proper functioning of buffer over a very long period of time during which it must remain physically, chemically and mineralogically stable. The long term stability of bentonite buffer depends on varying temperature and evolution of groundwater composition of host rocks in a complex way. The groundwater in the vicinity of deep crystalline rock is often characterized by high solute concentrations and the geotechnical engineering response of bentonite buffer could be affected by the dissolved salt concentration of the inflowing ground water. Also during the initial period, radiogenic heat produced in waste canisters would radiate into buffer and the heat generated would lead to drying and some shrinkage of bentonite buffer close to canister. This could alter the dry density, moisture content and in turn the hydro-mechanical properties of bentonite buffer in DGR conditions. India has variety of bentonite deposits in North-Western states of Rajasthan and Gujarat. Previous studies on Indian bentonites suggest that bentonite from Barmer district of Rajasthan (termed as Barmer-1 bentonite) is suitable to serve as buffer material in DGR conditions. Nuclear power agencies of several countries have identified suitable bentonites for use as buffer in DGR through laboratory experiments and large scale underground testing facilities. Physico-chemical, mineralogical and engineering properties of Kunigel VI, Kyungju, GMZ, FoCa clay, MX-80, FEBEX and Avonseal bentonites have been extensively studied by Japan, South Korea, China, Belgium, Sweden, Spain, Canada. It is hence essential to examine the suitability of Barmer-1 bentonite as potential buffer in DGR and compare its physico-chemical and hydromechanical properties with bentonite buffers identified by other countries. The significant factors that impact the long-term stability of bentonite buffer in DGR include variations in moisture content, dry density and pore water chemistry. With a view to address these issues, the hydromechanical response of 70 % Barmer-1 bentonite + 30 % river sand mix (termed bentonite enhanced sand, BES specimens) under varying moisture content, dry density and pore water salt concentration conditions have been examined. The broad scope of the work includes: 1) Characterise the physico-chemical and hydro-mechanical properties of Barmer-1 bentonite from Rajasthan, India and compare its properties with bentonite buffers reported in literature. 2) Examine the influence of variations in dissolved salt concentration (of infiltrating solution), dry density and moisture content of compacted BES specimens on their hydro-mechanical response; the hydro-mechanical properties include, swell pressure, soil water characteristic curve (SWCC), unsaturated hydraulic conductivity, moisture diffusivity and unconfined compression strength. Organization of thesis: After the first introductory chapter, a detailed review of literature is performed to highlight the need for detailed characterisation of physico-chemical and hydromechanical properties of Barmer-1 bentonite for its possible application in DGR in the Indian context. Further, existing literature on hydro-mechanical response of bentonite buffer to changes in physical (degree of saturation/moisture content, dry density) and physico-chemical (solute concentration in pore water) is reviewed to define the scope and objectives of the present thesis in Chapter 2. Chapter 3 presents a detailed experimental programme of the study. Chapter 4 characterises Barmer-1 bentonite for physico-chemical (cation exchange capacity, pore water salinity, exchangeable sodium percentage) and hydro-mechanical properties, such as, swell pressure, saturated permeability, soil water characteristic curve (SWCC) and unconfined compression strength. The properties of Barmer-1 bentonite are compared with bentonite buffers reported in literature and generalized equations for determining swell pressure and saturated permeability coefficient of bentonite buffers are arrived at. Chapter 5 describes a method to determine solute concentrations in the inter-lamellar and free-solutions of compacted BES (bentonite enhanced sand) specimens. The solute concentrations in micro and macro pore solutions are used to examine the role of osmotic flow on swell pressures developed by compacted BES specimens (dry density 1.50-2.00 Mg/m3) inundated with distilled water and NaCl solutions (1000-5000 mg/L). The number of hydration layers developed by the compacted BES specimens on inundation with salt solutions in constant volume swell pressure tests is controlled by cation hydration/osmotic flow. The cation hydration of specimens compacted to dry density of 2.00 Mg/m3 is mainly driven by matric suction prevailing in the clay microtructure as the number of hydration layers developed at wetting equilibrium are independent of the total dissolved solids (TDS) of the wetting solution. Consequently, the swell pressures of specimens compacted to 2.00 Mg/m3 were insensitive to the salt concentration of the inundating solution. The cation hydration of specimens compacted to dry density of 1.50 Mg/m3 is driven by both matric suction (prevailing in the clay micro-structure) and osmotic flow as the number of hydration layers developed at wetting equilibrium is sensitive to the TDS of the wetting solution. Expectedly, the swell pressures of specimens compacted to 1.50 Mg/m3 responded to changes in salt concentration of the inundating solution. The 1.75 Mg/m3 specimens show behaviour that is intermediate to the 1.50 and 2.00 Mg/m3 series specimens. Chapter 6 examines the influence of initial degree of saturation on swell pressures developed by the compacted BES specimens (dry density range: 1.40- 2.00 Mg/m3) on wetting with distilled water from micro-structural considerations. The micro-structure of the bentonite specimens are examined in the compacted and wetted states by performing X-ray diffraction measurements. The initial degree of saturation is varied by adding requisite amount of distilled water to the oven-dried BES mix and compacting the moist mixes to the desired density. The montmorillonite fraction in the BES specimens is responsible for moisture absorption during compaction and development of swell pressure in the constant volume oedometer tests. Consequently, it was considered reasonable to calculate degree of saturation based on EMDD (effective montmorillonite dry density) values and correlate the developed swell pressure values with degree of saturation of montmorillonite voids (Sr,MF). XRD measurements with compacted and wetted specimens demonstrated that if specimens of density series developed similar number of hydration layers on wetting under constant volume condition they exhibited similar swell pressures, as was the case for specimens belonging to 1.40 and 1.50 Mg/m3 series. With specimens belonging to 1.75 and 2.00 Mg/m3 series, greater number of hydration layers were developed by specimens that were less saturated initially (smaller initial Sr,MF) and consequently such specimens developed larger swell pressures. When specimens developed similar number of hydration layers in the wetted state, the compaction dry density determined the swell pressure. Chapter 7 examines the influence of salt concentration of infiltrating solution (sodium chloride concentration ranges from 1000- 5000 mg/L) on SWCC relations, unsaturated permeability and moisture diffusivity of compacted BES specimens. Analysis of the experimental and Brooks and Corey best fit plots revealed that infiltration of sodium chloride solutions had progressively lesser influence on the micro-structure and consequently on the SWCC relations with increase in dry density of the compacted specimens. The micro-structure and SWCC relations of specimens compacted to 1.50 Mg/m3 were most affected, specimens compacted to 1.75 Mg/m3 were less affected, while specimens compacted to 2.00 Mg/m3 were unaffected by infiltration of sodium chloride solutions. Variations in dry density of compacted bentonite impacts the pore space available for moisture flow, while, salinity of wetting fluid impacts the pore structure from associated physico-chemical changes in clay structure. Experimental results showed that the unsaturated permeability coefficient is insensitive to variations in dry density and solute concentration of wetting liquid, while, the effective hydraulic diffusivity is impacted by variations in these parameters. Chapter 8 summarises the major findings of the study.