Dissertations / Theses on the topic 'Simultaneous synthesis'

Mestrado em Engenharia Física
Neste trabalho é descrito o estudo de estruturas híbridas de grafeno e diamante nano-cristalino (GDH) sintetizadas por deposição química em fase vapor por plasma de micro-ondas (MPCVD) em cobre. Foram investigadas técnicas de controlo da nucleação do diamante nano-cristalino, tendo sido encontrados dois processos com sucesso. Procedeu-se ainda à caracterização estrutural, morfológica e ótica das amostras por análise de SEM, TEM, AFM, EFM, medidas de transmitância UV-Vis e espetroscopia de Raman. A avaliação das propriedades de transporte destes materiais foi efetuada pela medição da curva de transferência de transístores de efeito de campo produzidos para o efeito, sendo os GDHs produzidos o material ativo do canal. Foram observadas baixas mobilidades devido à hidrogenação do grafeno. Em linha com resultados teóricos da literatura, foram encontradas evidências de abertura do hiato energético do grafeno, um potencial desenvolvimento para a aplicação em dispositivos de comutação lógica.
In this work, hybrid structures of graphene and nano-crystalline diamond (GDH) produced by microwave plasma chemical vapor deposition (MPCVD) in copper substrates are studied. The control of the diamond clusters nucleation was investigated, having two different approaches been identified as promising. Structural, morphological and optical characterization was carried out by SEM, TEM, AFM, EFM, UV-Vis transmittance, and Raman spectroscopy. The transport properties of this material were analyzed through the transfer curve of field-effect transistors with GDH channels. Low mobilities were found due to graphene hydrogenation. In line with theoretical studies, evidences were found of graphene band gap opening, a potential breakthrough for the development of logical switching devices.

This study addresses the criticism leveled at A.C.T. Mathematics teachers with regard to their failure to use any other method of teaching than chalk-and-talk. By considering the changed needs of society for mathematics and the changed perceptions by society of education, the criticism is placed in context. The importance of spatial ability for mathematics is examined in the context of theories of cognitive abilities and its current under utilization within the classroom. On the basis of the increased need to utilize more talent the study was designed to operationalise in the classroom the constructs of simultaneous and successive synthesis, derived from Luria's model of brain functioning. The question of gender differences in mathematics achievment and spatial ability is addressed. The possible role of the maturation of language in determining differences in the acquistion of ability to form simultaneous synthesis is briefly discussed. The study was designed to utilize and enhance simultaneous synthesis. By demonstrating an Aptitude-Treatment Interaction it was intended to confirm that students, who function at a high level in simultaneous synthesis but at a low level in successive synthesis, would achieve more with experience with spatial activates than in a more traditional chalk-and-talk classroom. Gender differences in achievement were not found. Gender differences in successive/simultaneous profiles were found in accordance with theory predictions. The need for the duration of longer treatment periods is briefly discussed in the context of funding and the appearance of greater efficiency of traditional teaching methods when the students are functioning at the highest level of symbolic thought.

This thesis explores suitable methodological frameworks for modelling geographical hierarchical data sets by bringing together spatial and multilevel modelling approaches. The primary reason is that for a geographically hierarchical data, two types of dependence effect are expected: the spatial dependence arising from the geographical proximity and the membership based group dependence effect. Three different frameworks are proposed in this study. First, in terms of extending the Geographically Weighted Regression (GWR) model to accommodate a hierarchical data structure, a contextualised GWR is developed. The contextual information is incorporated into a GWR model by adjusting the geographical weights matrix to measure proximity not only in terms of distance but also with respect to an attribute space defined by measures of each observation's neighbourhood. Next, by integrating spatial econometric and multilevel modelling approaches, this study develops a hierarchical spatial autoregressive model (HSAR) that allows for simultaneously modelling the group dependence effect and the spatial interaction effect at each level of the data hierarchy. A series of Monte Carlo simulation studies show that the HSAR model performs well in terms of retrieving the true model parameters accurately. In contrast, both the classic spatial econometric and multilevel models perform poorly in the presence of both spatial interactions and group dependence. Finally, turning to a usual two-level hierarchical survey data where individuals nest into areas, this research develops a spatial random slope multilevel model that can simultaneously model spatial interactions across the higher level areas and correlations between random effects within each area. The essence of the spatial random slope multilevel model is to regard random effect at the area level as a spatial process characterised by a multivariate conditional autoregressive (CAR) process. In combination, the thesis makes important contributions to a coming together of spatial and multilevel modelling for better investigating geographically hierarchical data.

Förfrågan efter nya och mer avancerade applikationer är en pågående process vilket leder till en konstant utveckling av nya material. För att förstå relationen mellan en applikations egenskaper och dess sammansättning krävs full förståelse och kontroll över materialets uppbyggnad. En sådan kontroll över uppbyggnaden hos material hittas i en undergrupp till dendritiska polymerer som kallas dendrimerer. I den här doktorsavhandlingen belyses nya metoder för att framställa dendrimer med hjälp av selektiva kemiska reaktioner. Sådana selektiva reaktioner kan hittas inom konceptet klickkemi och har i detta arbete kombinerats med traditionell anhydrid- och karbodiimidmedierad kemi. Denna avhandling diskuterar en accelererad tillväxtmetod, dendrimerer med inre och yttre reaktiva grupper, simultana reaktioner och applikationer baserade på dessa dendritiska material. En accelererad tillväxtmetod har utvecklats baserad på AB2- och CD2-monomerer. Dessa monomerer tillåter tillväxt av dendrimerer utan att använda sig av skyddsgruppkemi eller aktivering av ändgrupper. Detta gjordes genom att kombinera kemoselektiviteten hos klickkemi tillsammans med traditionell syraklorid kopplingar. Dendrimerer med inre alkyn- eller azidfunktionalitet syntetiserades genom att använda AB2C-monomerer. Den dendritiska tillväxten skedde med hjälp av karbodiimidmedierad kemi. Monomererna som användes bär på en C-funktionalitet, alkyn eller azid, och på så sätt byggs får interiören i de syntetiserade dendrimeren en inneburen aktiv funktionell grupp. Ortogonaliteten hos klickkemi användes för att sammanfoga monomerer till en dendritisk struktur. Traditionell anhydridkemi- och klickemireaktioner utfördes samtidigt och på så sätt kunde dendritiska strukturer erhållas med färre antal uppreningssteg. En ljusemitterande dendrimer syntetiserades genom att koppla azidfunktionella dendroner till en alkynfunktionell cyclenkärna. Europiumjoner inkorporerades i kärnan varpå dendrimerens fotofysiska egenskaper analyserades. Mätningarna visade att den bildade triazolen hade en sensibiliserande effekt på europiumjonen. Termiska studier på några av de syntetiserade dendrimerer utfördes för att se om några av dem kunde fungera som templat vid framställning av isoporösa filmer.
The need for new improved materials in cutting edge applications is constantly inspiring researchers to developing novel advanced macromolecular structures. A research area within advanced and complex macromolecular structures is dendrimers and their synthesis. Dendrimers consist of highly dense and branched structures that have promising properties suitable for biomedical and electrical applications and as templating materials. Dendrimers provide full control over the structure and property relationship since they are synthesized with unprecedented control over each reaction step. In this doctoral thesis, new methodologies for dendrimer synthesis are based on the concept of click chemistry in combination with traditional chemical reactions for dendrimer synthesis. This thesis discusses an accelerated growth approach, dendrimers with internal functionality, concurrent reactions and their applications. An accelerated growth approach for dendrimers was developed based on AB2- and CD2-monomers. These allow dendritic growth without the use of activation or deprotection of the peripheral end-groups. This was achieved by combining the chemoselective nature of click chemistry and traditional acid chloride reactions. Dendrimers with internal azide/alkyne functionality were prepared by adding AB2C monomers to a multifunctional core. Dendritic growth was obtained by employing carbodiimide mediated chemistry. The monomers carry a pendant C-functionality (alkyne or azide) that remains available in the dendritic interior resulting in dendrimers with internal and peripheral functionalities. The orthogonal nature of click chemistry was utilized for the simultaneous assembly of monomers into dendritic structures. Traditional anhydride chemistry and click chemistry were carried out concurrently to obtain dendritic structures. This procedure allows synthesis of dendritic structures using fewer purification steps. Thermal analyses on selected dendrimers were carried out to verify their use as templates for the formation of honeycomb membranes. Additionally, a light emitting dendrimer was prepared by coupling of azide functional dendrons to an alkyne functional cyclen core. A Europium ion was incorporated into the dendrimer core, and photophysical measurements on the metal containing dendrimer revealed that the formed triazole linkage possesses a sensitizing effect.
QC 20100629

In this work we have prepared Si and SI(1-X)GE(X) nanocrystals by rf magnetron cosputtering method. The eect of annealing parameters and Ge content of x on the structural and optical properties sandwiched SiO2/SiO2: Si: Ge/SiO2 nanostructures have been investigated. For characterization we have used cross-sectional high resolution electron microscope (HREM), X-ray diraction (XRD), Raman spectroscopy (RS), Fourier transform infrared (FTIR), photoluminescence (PL), and temperature dependent PL (TDPL) techniques. It was shown that Ge content of x, annealing temperature, and annealing time are important parameters aecting the structural and optical properties of the nanocrystals. We have observed a uniform SI(1-X)GE(X) nanocrystal formation upon annealing at relatively low temperatures and short annealing time. However, Ge-rich SI(1-X)GE(X) nanocrystals do not hold their compositional uniformity when annealed at high temperatures for enough long time. A segregation process leads to the separation of Ge and Si atoms from each other and formation of Si-rich core covered by a Ge-rich shell. Related to the optical properties of Si and SI(1-X)GE(X) nanocrystals, influence of annealing treatments and Ge content of x on the simultaneous observation and relative contribution of quantum confined and interface related radiative emission to PL spectra are investigated. On the other hand, temperature dependent photoluminescence (TDPL) measurements have been applied to investigate in detail the involving PL mechanisms and the competing thermally activated emission process and the thermally activated escape process of carriers into nonradiative recombination centers and/or tunneling of the excitons into the interface or to larger nanocrystals.

Doped semiconductor quantum dots (QDs) comprise an important subclass of nanomaterials in which a small quantity of impurity is added intentionally, adding another degree of freedom to alter their size-dependent physical and electronic properties. Intense, tunable, long lived and stable photoluminescence make them quintessential candidates for many opto-electronic applications including solid-state lighting, display devices and biomedical imaging. ZnSe QDs, which are blue-emitting fluorophores, were doped with Cu⁺¹ to redshift their photoluminescence (PL) to green region of the visible spectrum. These Cu-doped ZnSe QDs were then codoped with Al³⁺, Ga ³⁺ and In³⁺ to improve the PL quantum yield (QY) by eliminating the defect states originating from charge imbalance created by aliovalent doping. Codoping also resulted in further redshifting of the PL, covering most of the visible spectrum, making them potential candidates for use in solid-state lighting and as optical down converters in next generation light emitting diodes (LEDs). To better understand the optical properties of these materials, local structure around the luminescent centers was investigated by extended X-ray absorption fine structure (EXAFS). Cu was found to occupy a distorted tetrahedral site with the codopant residing in a substitutional Zn site. Based on the structural information obtained by EXAFS, density functional theory calculations (DFT) were performed to get a clear picture of the energy levels associated with the electronic transitions. Furthermore, the dynamics studies of the exciton and charge carriers were carried out to get deeper insight of the various photophysical processes involved. The fluorescence lifetime was increased approximately 10 times after doping.

The multielectron catalytic reactions often involve multimetallic clusters, where the reaction is controlled by the electronic and spin coupling between metals and ligands to facilitate charge transfer, bond formation/breaking, substrate binding, and release of products. A method was developed to detect X-ray emission signal from multiple elements simultaneously to probe the electronic structure and sequential chemistry that occurs between the elements. A wavelength dispersive spectrometer based on the von-Hamos geometry was used, that disperses Kβ emission signals of multiple elements onto an area detector, and enables an XES spectrum to be measured in a single-shot mode. This overcomes the scanning needs of the Rowland circle spectrometers, and the data is free from temporal and normalization errors, and therefore ideal to follow sequential chemistry at multiple sites. This method was applied to MnO_x based electrocatalysts, and the effect of Ni addition was investigated. Electro-deposited Mn oxide catalyses oxygen-evolution reaction (OER) and oxygen-reduction reaction (ORR) at different electrochemical potentials under alkaline condition. Incorporation of Ni reduced the low valent Mn component resulting in higher average oxidation state of Mn in MnNiOx under ORR and OER conditions, when compared to MnO _x under similar conditions. The reversibility of the electrocatalyst was also found to improve by the inclusion of Ni.

Cette thèse est composée de deux parties principales. Premièrement, l'accès synthétique hélicosélectif à une nouvelle série de dioxa[6]hélicènes dioxa configurationnellement stables à partir de précurseurs achiraux simples a été développé. L’hélice est créée et contrôlée au cours d'une réaction domino organocatalysée comprenant une alkylation de Michael suivie d’un couplage C–O, qui fournit les 2-nitrodihydrofuranes chiraux sous forme d’uniques stéréoisomères présentant à la fois une chiralité centrale (deux atomes de carbone stéréogènes) et une chiralité hélicoïdale. Il s’agit du premier cas d'une transformation chimique dans laquelle les chiralités centrales et hélicoïdales sont contrôlées simultanément. Ceci donne accès à des molécules chirales très originales pour la synthèse d'hétérohelicènes optiquement actifs par élimination de HNO2 avec une excellente rétention la chiralité hélicoïdale dans la plupart des cas. Dans une second partie, une nouvelle classe d’organocatalyseurs de type acides de Brønsted a été développée dans laquelle la chiralité est centrée sur l'atome de phosphore. Les acides thiophosphiniques P-stéréogènes chiraux optiquement actifs ont été synthétisés., ce qui ouvre de nouvelles opportunités en l’organocatalyse énantiosélective. Ces nouveaux organocatalyseurs ont notamment été utilisés dans la réaction de Pictet-Spengler et les produits ont été obtenus avec de bons rendements et énantiosélectivité modérée (jusqu'à 47% ee). Cette première étape valide le concept initial mais une optimisation supplémentaire est nécessaire pour atteindre des excès énantiomériques plus élevés et pour rendre ces organocatalyseurs plus généraux
This PhD thesis is composed of two main parts. First, the expedient helicoselective synthetic access to a new series of configurationally stable dioxa[6]helicenes from simple achiral precursors was developed. The helicity is created and controlled during an organocatalyzed domino Michael/C–O alkylation step, which delivers chiral 2-nitrodihydrofurans as single stereoisomers featuring both central chirality (two stereogenic carbon atoms) and a helical shape. Interestingly, this represents the first case of a catalytic chemical transformation in which both central and helical chiralities are controlled simultaneously, offering unprecedented chiral platform molecules for the synthesis of enantioenriched heterohelicenes by simple base-promoted elimination of HNO2 with excellent retention of the helical information in most cases. Secondly, a new design for Brønsted acid organocatalysis was developed in which the chirality is centered on the phosphorus atom. Chiral P-stereogenic thiophosphinic acids were synthesized in high enantiomeric excess. This opens new synthetic opportunities for both hydrogen-bonding and ion-pairing enantioselective organocatalysis. These new catalysts were used notably in Pictet-Spengler reactions delivering the products in moderate enantioselectivity (up to 47% ee). This first step validate the concept but further optimization is necessary to reach higher enantiomeric excess and to make these catalysts more general

Microwave-assisted novel synthesis of poly(dibromophenylene oxide) or poly(diiodophenylene oxide) (P), conducting polymer (CP) and/or crosslinked polymer (CLP) and/or radical ion polymer (RIP) were achieved simultaneously from lithium, sodium or potassium 2,4,6-bromophenolate or sodium 2,4,6-iodophenolate in a very short time interval. Polymerizations were carried out by constant microwave energy with different time intervals varying from 1 to 20 min
or at constant time intervals with variation of microwave energy from 70 to 900 watt
or varying the water content from 0.5 to 5 ml at constant time intervals and microwave energy. Poly(dihalophenylene oxide) and radical ion polymers were characterized by FTIR (Fourier Transform Infrared), 1H-NMR (Proton Nuclear Magnetic Resonance), 13C-NMR (Carbon-13 Nuclear Magnetic Resonance), TGA/ FTIR (Thermal Gravimetric Analysis / Fourier Transform Infrared), DSC (Differential Scanning Calorimeter), SEM (Scanning Electron Microscope), ESR (Electron Spin Resonance), GPC (Gel Permeation Chromatography), UV-Vis (UV-Visible Spectroscopy), Light Scattering and Elemental Analysis. Conducting and crosslinked polymers were characterized by FTIR, TGA/ FTIR, DSC, SEM, ESR, XRD (Powder Diffraction X-Ray) and Elemental Analysis. The effects of heating time, microwave energy and water content on the percent conversion and the polymer synthesis were also investigated.

Biomedical Sciences
Ph.D.
PARP inhibitors (PARPi) have been used to induce synthetic lethality in BRCA-deficient tumors in clinical trials with limited success due to the development of resistance to PARPi. BRCA-deficient cells are unable to repair DNA double strand breaks by the accurate homologous recombination repair (HR), and therefore rely on alternative DNA repair pathways for survival. We hypothesized that RAD52-mediated DNA repair mechanisms remain active and are thus protecting some PARPi-treated BRCA-deficient tumor cells from apoptosis, and that targeting RAD52 should enhance the synthetic lethal effect of PARPi. We show here that RAD52 inhibitors (RAD52i) attenuated single-strand annealing (SSA) and residual HR activity in BRCA-deficient cells. Simultaneous targeting of PARP1 and RAD52 with small molecule inhibitors or via expression of dominant-negative mutants induced an accumulation of DSBs and selective eradication of BRCA-deficient solid tumor and leukemia cells, while BRCA-proficient cells were unaffected. Parp1-/-Rad52-/- transgenic mice are healthy and indistinguishable from wild-type mice due to the presence of the BRCA-pathway, and Parp1-/-Rad52-/- mice with inducible BRCA1-deficient leukemia displayed significantly prolonged survival when compared to Parp1-/- and Rad52-/- counterparts. Finally, PARPi + RAD52i selectively targeted BRCA1-deficient solid tumors in immunodeficient mice with minimal toxicity to normal cells and tissues which are protected by the BRCA-pathway, indicating minimal side effects. In conclusion, our data indicate that combination treatment of RAD52i and PARPi will significantly improve therapeutic outcome of BRCA-deficient malignancies compared to treatment with PARPi monotherapy, while leaving healthy cells and tissues unharmed.
Temple University--Theses

Thesis (MScEng)--Stellenbosch University, 2012
ENGLISH ABSTRACT: Through many years of research, a number of production schemes have been developed for converting lignocellulosic biomass into transport fuels. These technologies have been assessed through a number of techno-economic studies for application in a particular context in terms of the technical and economic feasibility. However, previous studies using these methods have tended to lack vigour in various aspects. Either the energy efficiency of the processes were not maximised through adequate heat integration, or a competing technology which existed was not considered. From an economic perspective, the financial models would often lack the vigour to account for the risk and uncertainty that is inherent in the market prices of the commodities. This phenomenon is especially relevant for the biofuel industry that faces the full fledge of uncertainties experienced by the agricultural sector and the energy sector. Furthermore, from an environmental perspective, the techno-economic studies had often ignored the environmental impacts that are associated with biofuel production. Thus, a comparative study could have favoured an option due to its economic feasibility, while it could have had serious environmental consequences. The aim of this study was to address these issues in a South African context, where biofuels could be produced from sugarcane bagasse. The first step would be to modify an existing simulation model for a bioethanol scenario that operates with a Separate Hydrolysis and Fermentation (SHF process) configuration into a second processing scenario that operates with a Simultaneous Saccharification and Fermentation (SSF process) configuration using reliable experimental data. The second step was to ensure that the maximum energy efficiency of each scenario was realised by carrying out pinch point analysis as a heat integration step. In contrast to these biological models is the thermochemical model that converts bagasse to gasoline and diesel via gasification, Fischer-Tropsch synthesis and refining (GFT process). While there were no significant advances in technology concerning this type of process, the energy efficiency was to be maximised with pinch point analysis. The GFT process obtained the highest energy efficiency of 50.6%. Without the affects of pinch point technology, the efficiency dropped to 46%, which thus emphasises the importance of heat integration. The SSF had an efficiency of 42.8%, which was superior to that of the SHF at 39.3%. This resulted from a higher conversion of biomass to ethanol in the SSF scenario. Comparing the SHF model to an identical model found in literature that did not have pinch point retrofits, this study showed lower efficiency. This arose because the previous study did not account for the energy demands of the cold utility systems such as the cooling tower operation, which has been shown in this study to account for 40% of the electrical energy needs. The economic viability of all three processes was assessed with Monte Carlo Simulations to account for the risks that the fluctuations in commodity prices and financial indices pose. This was accomplished by projecting the fluctuations of these parameters from samples of a historical database that has been transformed into a probability distribution function. The consequences were measured in terms of the Net Present Value (NPV) and Internal Rate of Return (IRR) for a large number of simulations. The results of these variables were aggregated and were then assessed by testing the probability that the NPV<0, and that the IRR recedes below the interest rate of 12.64%. The investment was thus deemed unfeasible if these probabilities were greater than 20%. Both biological models were deemed profitable in terms of this standard. The probabilities were 13% for the SSF and 14% for the SHF. The GFT process however was deemed completely unfeasible because the probability that the NPV<0 was 78%. Given that the GFT process had the highest energy efficiency, this result arises mainly because the capital investment of 140,000USD/MWHHV of biomass energy input is to enormous for any payback to be expected. The environmental footprint of each process was measured using Life Cycle Assessments (LCAs). LCAs are a scientifically intricate way of quantifying and qualifying the effects of a product or process within a specified boundary. The impacts are assessed on a range of environmental issues, such as Global Warming, Acidification, Eutrophication and Human toxicity. Furthermore, if the project under concern has multiple output products, then the impacts are distributed between the output products in proportion to the revenue that each generates. The impacts were either relative to the flow of feedstock, which was 600MW of bagasse, or to the functional unit, which was the amount of fuel required to power a standard vehicle for a distance of 1 kilometre. In either case, the GFT scenario was the least burdening on the environmental. This was expected because the GFT process had the highest energy efficiency and the process itself lacked the use of processing chemicals. Relative to the feedstock flow, the SSF was the most environmentally burdening scenario due to the intensive use of processing chemicals. Relative to the functional unit, the SHF was the most severe due to its low energy efficiency. Thus, the following conclusions were drawn from the study:  The GFT is the most energy and environmentally efficient process, but it showed no sign of economic feasibility. iv  There is no significant difference in the economic and environmental evaluation of the SSF and SHF process, even though the SSF is considered to be a newer and more efficient process. The major cause of this is because the setup of the SSF model was not optimised.
AFRIKAANSE OPSOMMING: Deur baie jare van navorsing is ‘n aantal produksie-skemas vir die omskakeling van lignosellulose biomassa na vloeibarebrandstof ontwikkel. Hierdie tegnologië is geassesseer ten opsigte van die tegniese en ekonomiese haalbaarheid deur middel van tegno-ekonomiese studies in bepaalde tekste. Tog het hierdie vorige studies besliste beperkings gehad. Of die energie-doeltreffendheid van die proses is nie gemaksimeer deur voldoende hitte-integrasie nie, of 'n mededingende tegnologie wat bestaan is nie oorweeg nie. Vanuit 'n ekonomiese perspektief, was die finansiële modelle dikwels nie die omvattend genoeg om rekening te hou met die risiko en onsekerheid wat inherent is in die markpryse van die kommoditeite nie. Hierdie verskynsel is veral relevant vir die biobrandstof bedryf wat die volle omvang van onsekerhede ervaar waaraan die landbousektor en die energiesektoronderhewig is. Verder het die tegno-ekonomiese studies dikwels die omgewingsimpakte wat verband hou met biobrandstofproduksie geïgnoreer. Dus kon ‘n opsie deur die ekonomiese haalbaarheid bevoordeel word, ten spyte van die ernstige omgewingsimpakte wat dit kon inhou. Die doel van hierdie studie was om hierdie kwessies aan te spreek in 'n Suid-Afrikaanse konteks, waar biobrandstof uit suikerriet bagasse geproduseer kan word. Die eerste stap was om 'n bestaande simulasiemodel vir 'n bio-scenario wat met Afsonderlike Hidroliese en Fermentasie (SHF proses) stappe werk, te modifiseer vir 'n tweede verwerking scenario wat met 'n gelyktydige Versuikering en Fermentasie (SSF proses) konfigurasie werk. Die verandering is gedoen deur die gebruik van betroubare eksperimentele data. Die tweede stap was om te verseker dat elke scenario die maksimum energie-doeltreffendheid het, deur 'n hitte-integrasie stap, wat gebruik maak van “pinch-point” analise. In teenstelling met hierdie biologiese modelle, is daar die thermochemiese roete waar petrol en diesel van bagasse vervaardig word via vergassing, Fischer-Tropsch-sintese en rafinering (GFT proses). Daar was geen betekenisvolle vooruitgang in tegnologie vir hierdie proses nie, maar die energie-doeltreffendheid is gemaksimeer word deur energie-integrasie. Die GFT proses toon die hoogste energie-doeltreffendheid van 50,6%. Sonder die invloed van energie-integrasie het die doeltreffendheid gedaal tot 46%, wat dus die belangrikheid van hitte-integrasie beklemtoon. Die SSF het 'n effektiwiteit van 42,8% gehad, wat beter was as dié 39,3% van die SHF opsie. Hierdie hoër effektiwiteit wasas gevolg van die hoër omskakeling van biomassa na etanol in die SSF scenario. Die energie doeltreffendheid vir die SHF-model was laer as met 'n identiese model (sonder energie-integrasie) wat in die literatuur gevind wat is. Dit het ontstaan omdat die vorige studie nie 'n volledig voorsiening gemaak het met die energie-eise van die verkillingstelselsnie, wat tot 40% van die elektriese energie behoeftes kan uitmaak. Die ekonomiese lewensvatbaarheid van al drie prosesse is bepaal met Monte Carlo simulasies om die risiko's wat die fluktuasies in kommoditeitspryse en finansiële indekse inhou, in berekening te bring. Hierdie is bereik deur die projeksie van die fluktuasies van hierdie parameters aan die hand van 'n historiese databasis wat omskep is in 'n waarskynlikheid verspreiding funksie. Die gevolge is gemeet in terme van die netto huidige waarde (NHW) en Interne Opbrengskoers (IOK) vir 'n groot aantal simulasies. Die resultate van hierdie veranderlikes is saamgevoeg en daarna, deur die toets van die waarskynlikheid dat die NPV <0, en dat die IRR laer as die rentekoers van 12,64% daal, beoordeel. Die belegging is dus nie realiseerbaar geag as die waarskynlikhede meer as 20% was nie. Beide biologieseprosesse kan as winsgewend beskou word in terme van bostaande norme. Die waarskynlikhede was 13% vir die SSF en 14% vir die SHF. Aangesien die NHW van die GFT-proses onder 0 met ‘n waarskynlikheid van 78% is, is die opsie as nie-winsgewend beskou. Gegewe dat die GFT-proses die hoogste energie-doeltreffendheid het, is die resultaat hoofsaaklik omdat die kapitale belegging van 140,000 USD / MWHHV-biomassa energie-inset te groot is, om enige terugbetaling te verwag. Die omgewingsvoetspoor van elke proses is bepaal deur die gebruik van Lewens Siklus Analises (“Life Cycle Assessments”) (LCAS). LCAS is 'n wetenskaplike metodeom die effek van ‘n produk of proses binne bepaalde grense beide kwalitatief en kwantitatief te bepaal. Die impakte word beoordeel vir 'n verskeidenheid van omgewingskwessies, soos aardverwarming, versuring, eutrofikasie en menslike toksisiteit. Voorts, indien die projek onder die saak verskeie afvoer produkte het, word die impakte tussen die afvoer produkte verdeel, in verhouding tot die inkomste wat elkeen genereer. Die impak was met of relatief tot die vloei van roumateriaal (600MW van bagasse), of tot die funksionele eenheid, wat die hoeveelheid van brandstof is om 'n standaard voertuig aan te dryf oor 'n afstand van 1 kilometer. In al die gevalle het die GFT scenario die laagste belading op die omgewing geplaas. Hierdie is te verwagte omdat die GFT proses die hoogste energie-doeltreffendheid het en die proses self nie enige addisionele chemikalieë vereis nie. Relatief tot die roumateriaal vloei, het die SSF die grootse belading op die omgewing geplaas as gevolg van die intensiewe gebruik van verwerkte chemikalieë. Relatief tot die funksionele eenheid, was die SHF die swakste as gevolg van sy lae energie-doeltreffendheid.

As especificações do biodiesel são garantidas por um rigoroso controle de qualidade; entre outros parâmetros, a quantificação de antioxidantes é fundamental para assegurar um produto satisfatório para comercialização. No presente estudo, foram desenvolvidas técnicas voltamétricas e cromatográficas para análise direta de BHA, TBHQ, BHT e PG em biodiesel. Medidas por voltametria de pulso diferencial (DPV) em mistura biodiesel:etanol 1:1 (v/v), contendo perclorato de tetra-hexilamônio como eletrólito suporte e empregando ultramicroeletrodo (ume) de Pt, mostraram picos da corrente diferencial de oxidação bem definidos para TBHQ e PG, sendo obtidos gráficos de calibração lineares na faixa de concentrações de 10-3 mol L-1. Analogamente, empregando um ume de Au em microemulsão de biodiesel livre de surfactante (SFME) contendo tetrafluoroborato de tetra-n-butilamônio, medidas por DPV apresentaram picos da corrente diferencial bem definidos para TBHQ e BHT. Para esses compostos, foram obtidos gráficos de calibração lineares na faixa de concentrações de 10-4 mol L-1. Em ambos os casos, devido à sobreposição dos voltamogramas, os teores de antioxidantes foram calculados por um procedimento matemático de deconvolução empregando o software Origin 8.0®. A quantificação de BHA, BHT e TBHQ por cromatografia GC/qMS em biodiesel diluído em metanol apresentou linearidade entre 5 e 25 mg L-1, para cada um dos antioxidantes. Medidas por HPLC em fase reversa com coluna fenílica apresentaram boa separação dos picos cromatográficos na análise simultânea de BHA, BHT, TBHQ e PG assim como curvas de calibração com linearidade entre 10 e 80 mg L-1, para cada um dos antioxidantes. A identificação dos ésteres metílicos de ácidos graxos (FAMEs) no biodiesel foi realizada por UHPLC-ESI-Orbitrap/MS; os teores de FAMEs e antioxidantes permaneceram estáveis nas amostras fortificadas mesmo após 8 semanas de exposição à luz solar, porém diminuíram significativamente em amostras não-fortificadas. As metodologias propostas são de fácil preparo e baixo consumo de amostra, podendo vir a ser do interesse da indústria para o monitoramento de antioxidantes em biodiesel, na linha de produção. A principal vantagem é não ser necessário nenhum tipo de pré-tratamento da amostra: a simples diluição em metanol ou etanol ou a preparação do biodiesel na forma de SFME conferem rapidez e simplicidade à determinação dos antioxidantes investigados.
Biodiesel features are assured by strict quality control procedures; among those, antioxidants quantification is essential to guarantee a good and satisfactory final product for commercialization. In the present study, voltammetric and chromatographic methodologies were developed for direct analyses techniques of BHA, TBHQ, BHT and PG in biodiesel. Differential pulse voltammetry (DPV) in biodiesel:ethanol 1:1 (v/v), with tetrahexylammonium perchlorate as supporting electrolyte at a Pt ultramicroelectrode (ume), presented well-defined oxidation peaks for TBHQ and PG, with corresponding linear calibration graphs in the range of 10-3 mol L-1. Likewise, DPV at an Au ume in biodiesel surfactant-free microemulsion (SFME), with tetra-n-butylammonium tetrafluoroborate, presented well-defined oxidation peaks for TBHQ and BHT. For these compounds, linear calibration graphs were obtained in the range of 10-4 mol L-1. In both techniques, due to significant voltammograms overlapping, amounts of antioxidants were calculated through mathematical deconvolution process using software Origin 8.0®. BHA, BHT and TBHQ quantification by GC/qMS in biodiesel diluted in methanol presented linearity between 5 and 25 mg L-1 for each antioxidant. Reversed-phase liquid chromatography by HPLC using phenyl column showed good peak separation in simultaneous analysis of BHA, BHT, TBHQ and PG and calibration curves with linearity between 10 and 80 mg L-1. Biodiesel fatty acid methyl esters (FAMEs) identification was carried out by UHPLC-ESI-Orbitrap/MS; both FAMEs and antioxidants contents remained stable in spiked samples even after 8 weeks under sunlight exposure; in non-spiked samples, FAMEs content was significantly reduced. All proposed methodologies are easy to perform and present low sample consumption, which are interesting features for industry to monitor the aforementioned and other antioxidants in biodiesel. Their main advantage lies in the absence of any sample pre-treatment: the simple dilution in methanol or ethanol or biodiesel preparation as SFME deliver speed and simplicity for determination of target antioxidants.

L’objectif de ce travail a été de développer deux approches analytiques dédiées à l’analyse toxicologique des nouveaux produits de synthèse (NPS) dans différentes matrices biologiques (sang, urine et cheveux). La première est basée sur le criblage non ciblé par chimiluminescence sur biopuces et chromatographie liquide couplée à la spectrométrie de masse haute résolution (LC-HRMS) et la deuxième correspond à un criblage ciblé par spectrométrie de masse en tandem (LC-MS/MS). Ces deux approches ont ensuite été appliquées dans des études observationnelles pour évaluer la consommation de NPS dans des populations à risques de surdosage, de pharmacodépendance ou de soumission chimique dans un contexte clinique ou médico-judiciaire.La dernière partie a été consacrée au développement d’un nouvel outil analytique de traitement des données issues de la LC-HRMS qui a permis d’étudier le métabolisme de 9 NPS in vitro sur des cultures de microsomes du foie humain (HLM) et in vivo sur des échantillons biologiques d’usagers de ces drogues. Cette dernière approche a permis la création d’une bibliothèque de spectres de haute résolution composée de 228 métabolites dont certains ont été proposés comme marqueurs pertinents d’exposition aux NPS dont ils sont issus.Ce travail a été concrétisé par la rédaction de 10 publications scientifiques et a permis d’initier plusieurs collaborations pluridisciplinaires
The aim of the present work was to develop two analytical approaches dedicated to the analysis of new psychoactive substances in different biological matrices (blood, urine and hair). The first approach is based on untargeted screening by both biochip array technology chemiluminescence assay and liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) and the second corresponds to a targeted screening by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). These two approaches were then applied in observational studies to assess the consumption of NPS in high risk populations (overdose, drug abuse, drug facilitated crimes) in clinical and forensic settings. The last part of the work was devoted to the development of a new analytical tool for LC-HRMS data processing which made it possible to study the metabolism of 9 NPS In vitro on human liver microsomes (HLM) and In vivo in biological samples from drug users. This approach has enabled the creation of HRMS spectral library containing 228 metabolites, some of which have been proposed as relevant markers of NPS exposure.This work has resulted on 10 scientific publications and allowed to initiate many multidisciplinary collaborations

碩士
國立臺灣大學
電子工程學研究所
91
Signal integrity is emerging as an important issue as very large scale integration (VLSI) technology advances to nanoscale regime. In today's deep submicron (DSM) technology, metal width tends to decrease with length increasing due to the complex system integration. Large current due to a large number of cells switching may cause unacceptable current-resistance (IR) drop. Faster switching frequencies and thinner wires with a lower supply voltage will increase the possibility of functional failures due to the excessive IR drops. Traditionally power distribution network analysis is performed during the transistor-level and post-layout verification. Iteration cost is high at the end of the design flow. In this thesis, in order to achieve the single-pass design methodology, we incorporate a power analysis algorithm into floorplanning stage for early power planning. To ensure the IR drop acceptable at post floorplan. Experimental results based on five MCNC benchmark circuits and a 0.25-um technology show that the predicted IR drop is reduced during the floorplanning stage. With the power analysis considered at the floorplanning stage, we can reduce the IR drop error at the post-layout verification stage.

Dimethylether is a non-toxic liquefied gas, which is projected to become one of the fundamental chemical feedstock in the future. Dimethylether can be produced from syngas via a two-step (indirect) process that involves synthesis of methanol by hydrogenation of CO/CO2 over a copper based catalyst and subsequent dehydration of methanol to DME over an acidic catalyst. Alternatively, DME can be produced in an one-step (direct) process using a hybrid (bifunctional) catalyst system that permits both methanol synthesis and dehydration in a single process unit. In the present research work the production of DME has been studied by applying both the indirect and direct processes. Firstly, the methanol synthesis and methanol dehydration reactions involved in the indirect process have been studied separately. Afterwards, these two reactions have been combined in the direct DME production process by using a hybrid catalyst comprising a methanol synthesis and a methanol dehydration component. The methanol synthesis by CO2 hydrogenation has been investigated over commercial and home-made CuO/ZnO/Al2O3 catalysts with the aim to identify optimal experimental conditions (CO2:H2 ratio, flow rate, temperature) that could be then used in the direct conversion of CO2/H2 mixtures into methanol/DME. Obtained results reveal that the conversion of CO2 and the yields of reaction products (CH3OH and CO) increase when the concentration of H2 in the feed and the reaction contact time are increased. It was found that both Cu+/Cu0 species are important for the conversion of CO2/H2, although the presence of Cuo seems to be more important for selectivity/yield of methanol. The stability of the CuO/ZnO/Al2O3 catalyst has been also investigated. It was observed that the main reason for the deactivation of catalyst is the water produced via the methanol synthesis and reverse water gas shift reactions. However, the catalytic activity and products selectivity were recovered slowly to their original levels after applying a regeneration procedure, indicating that deactivation by water is reversible. The dehydration of methanol to dimethylether (DME) has been investigated over a range of catalysts including alumina, silica-alumina and zeolites with different physicochemical characteristics. The effects of temperature and the presence of water vapour in the feed on catalytic performance have been studied in detail. The reactivity of catalysts has been evaluated by determining the reaction rates per gram of catalyst per acid site (total: Brönsted+Lewis) and per Brönsted/Lewis mole ratio. In addition, the reaction mechanism has been investigated over a selected catalyst, with the use of transient-MS and in situ DRIFTS techniques. Results obtained for alumina catalysts show that the catalytic activity and selectivity are determined to a large extent by the textural properties, degree of crystallinity and total amount of acid sites of catalysts. In particular, the methanol conversion curve shifts toward lower reaction temperatures with an increase of specific surface area. However, the enhanced catalytic activity of high-SSA samples cannot be attributed solely to the higher amount of surface acid sites, implying that the reaction rate is determined to a large extent from other parameters, such as textural properties and degree of crystallinity. Results of mechanistic studies indicate that interaction of methanol with the Al2O3 surface results in the formation of two kinds of methoxy groups of different adsorption strength. Evidence is provided that DME evolution is associated with methoxy species that are weakly adsorbed on the Al2O3 surface, whereas more strongly held species decompose to yield surface formate and, eventually, CH4 and CO in the gas phase. Results obtained over zeolite catalysts show that catalytic performance depends on the topology of zeolites due to differences in micropore structure and Si/Al ratio as well as on the number, strength and nature of active acid sites. The activity of zeolite catalysts for the methanol dehydration to DME follows the order ZSM-5 > Ferrierite > Mordenite ~ Beta ~ USY > H-Y. The strong Brönsted acid sites of ZSM-5 zeolites with relatively high Si/Al ratio represent the most active sites in methanol dehydration to DME reaction. However, the overall reactivity of the ZSM-5 zeolites is also affected by the balance of the Brönsted to Lewis acid sites. The activity of Beta and USY zeolites is determined by both Lewis and Brönsted acid sites. The moderate/low reactivity of Ferrierite, Mordenite and H-Y zeolite are determined by the abundant Brönsted acid sites of relatively weak/moderate strength. The direct CO2 hydrogenation to methanol/DME has been investigated using admixed catalysts comprising a methanol synthesis (commercial copper based catalyst: CZA1) and a methanol dehydration component (different alumia/zeolite catalysts: γ-Al2O3, ZSM-5, W/γ-Al2O3, USY(6), Ferrierite(10)). It has been revealed that the conversion of CO2 is always lower than the corresponding equilibrium values predicted by thermodynamics, indicating operation in the kinetic regime. The nature of the methanol dehydration component of the admixed catalysts was found to be important for both CO2 conversion and methanol dehydration. In particular, DME selectivity/yield, depends strongly on the nature of acid sites (both Lewis and Brönsted) as well as the textural (meso/macro porosity) and topological properties of methanol dehydration component of the admixed catalysts. The yield of DME obtained at a temperature of 250oC decreases following the order CZA1/ZSM-5, CZA1/USY(6) > CZA1/Ferrierite(10) > CZA1/ W/γ-Al2O3 >> CZA1/γ-Al2O3. The long-term stability experiments conducted over selected bifunctional catalytic systems revealed that the catalysts deactivate with time-on-stream, mainly due to water produced via methanol synthesis, methanol dehydration and reverse water gas shift reactions. In case of the CZA1/ZSM-5 admixed catalyst the catalytic activity and products selectivity were almost recovered after regeneration indicating that deactivation by water is reversible.
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碩士
國立臺灣大學
機械工程學研究所
99
The purpose of this thesis is to design a continuous two-phase microreactor, which applies silicon oil to avoid fouling of gold nanoparticles on channel walls. A new DNA detection method was also devoloped. Gold nanoparticles grow into different shape when single-strand DNA or double-strand DNA is added to growth process. Absorption spectrum was measured to detect target DNA. There are four steps in the thesis. First, gold nanoparticles were synthesized in microreactor. Second, A coutinuous two-phase microreactor was designed to avoid gold nanoparticles fouling on channel walls. This design was analyzed by simulation and experiment. Third, gold nanoparticles were synthesized in the continuous two-phase microreactor. Last, the effects of single-strand DNA and double-strand DNA on synthesis of gold nanoparticles in centrifuge tube were determined. Results are divided into two parts. The first part is continuous two-phase microreactor. The simulation results show that annular flow is formed when the velocity of water is 0.2 m/s and the velocity of water is 0.1 m/s. Vertically straitified flow is formed when the velocity of water increases, while droplet flow is formed when the velocity of water decreases. The experiment results of flow configuration show the similar trend; however, the experimental velocity of water is about two times larger than the simulation to reach the same flow configuration. The continuous two-phase microreactor was then applied to the synthesis of gold nanoparticles. The results show that fouling on channel walls was reduced significantly. The second part is DNA detection. Absorption spectrum of gold nanoparticles synthesized with single-strand DNA has red shift compared with those synthesized without DNA. There is further red shift when gold nanoparticles are synthesized with double-strand DNA.

碩士
國立中正大學
化學工程研究所
87
The thesis is to produce the densified materials via the self-propagating high-temperature synthesis(SHS) with a simultaneously pressing by a hydraulic press. In this research, nickel-aluminum intermetallic(NiAl) and titanium-carbide(TiC) material systems were studied. The experiment was carried out in a glove-box type reactor, with a hydraulic press, custom design with pressurized body and oil tank separated, sitting inside the reactor. Two main parameters were studied including compaction pressure and pressing time. The products were take subjected to density measurement, scanning electron microscope(SEM), X-ray diffraction(XRD) and Vickers hardness analysis. According to results, under the 588 MPa and compaction at zero second after the end of combustion, the theoretical densities of NiAl and TiC were obtained 99.0% and 81.1%, respectively. Further, with compaction pressure and pressing time varied, we found that: for NiAl system 1. The increase of compaction pressure increased the relative density, decreased the grain size, increased the sample hardness and improved the product uniformity. Grain size and hardness would not further change obviously by an increasing pressure. 2. The delay of pressing time would cause the decrease of relative density, increase of grain size. This determination reached to a certain degree if the time delayed more. Besides, the delay of pressing time did not influence hardness and uniformity of products significantly. for TiC system 1. The increase of compaction pressure increased the relative density, decreased the grain size and improved the product uniformity. Relative density and grain size would not further change obviously by a increasing pressure. Besides, if pressing time is zero second after the end of combustion, the increase of compaction pressure would cause the incompleteness of reaction more significantly. 2. The delay of pressing time would cause the decrease of relative density, however, the structure would become looser if the time delayed more.

碩士
中原大學
電子工程研究所
94
Operation scheduling is the most important task in high-level synthesis. Most conventional operation scheduling algorithms paid attention to the minimization of control steps or the minimization of resources. However, as the design complexity continues to increase, huge peak power may lead to logic errors due to voltage drops or reliability problems due to electromigration. Due to the popularization of portable and wireless communication, low power design is getting very important. An efficient power management method is to use control logic to shut down unused operations. Operation delay selection is not violating any design constraint (timing and resource). In this paper, we present an ILP (integer linear programming) formulation to model the problem of simultaneous power management scheduling and operation delay selection for peak power reduction but the run time is too long. Therefore, we propose a heuristic algorithm achieves the near optimal solution. Benchmark data show that our approach can reduce peak power effectively.

碩士
大同大學
化學工程學系(所)
101
The dehydration reactions of glycerol with tert-butanol using Amberlyst-70 were performed and the two product phases (the organic phase and the aqueous phase) were obtained. The components of the organic phase contained tert-butanol(TBA), isobutylene (IB), di-isobutylene (DIBs), tri-isobutylene (TIBs) and HCs (hydrocarbons) while the components of the aqueous phase contained water, the unconverted tert-butanol and glycerol. Setting a higher conversion of glycerol as the operating objective, the optimal operation conditions were found (reaction time 8 hours, reaction temperature 190 and TBA/glycerol molar ratio 2) and a maximal conversion of glycerol (60%) was achieved. By a simple distillation of the organic phase, two cuts (the distillate cut with the boiling point less than 225℃ and the residue cut ) were obtained. The distillate cut could be used as an octane booster for gasoline because its octane number was higher than 100. Meanwhile, the residue cut could be adopted as a diesel fuel because its cetane index was 32 and possessed excellent cold filter plugging point (-19℃) and the pour point (-42℃).

碩士
國立中正大學
化學工程研究所
88
This thesis is to study the densification of TiC system when the carbon source of micro-scale has replaced by nano-scale. The experiment process is via the self-propagating high-temperature synthesis with a simultaneously pressing by a hydraulic press. The studied parameters are the ratio of added nano-carbon powder, time delay of pressing, pressing time holding, density of green pellet and compaction pressure. Besides, we also added different ratio metal powders into titanium-carbide to synthesis TiC/Me cermet materials, such as aluminum, nickel and titanium. Finally, the products were take subjected to density measurement, SEM, XRD, EDX mapping and Vickers hardness analysis. According to results, the addition of nano-carbon powder adding can raise the relative density of TiC ceramic and TiC/Me cermet. When we compacted at 0.5 second after the end of ignition in 686 MPa compaction pressure, the relative density of TiC can reach to 98.98 %. In the same condition, but proceeding simultaneous pressing at 0.7 second after the end of ignition, the TiC/Me systems have the higher relative density and hardness while the adding ratio of metal powder is 25 %wt. The relative density and hardness of TiC/Me systems are : TiC/Al : 99.78 %, 636 HV ; TiC/Ni : 99.53 %, 1711 HV and TiC/Ti : 99.67 %, 1323 HV。 The control of experiment parameters would affect the relative density of material. According to results, we can find out the relationship between various parameters and TiC ceramic or TiC/Me cermet : 1. Nano-carbon powder added can increase the relative density of material. As the amount of nano-scale carbon powder increasing, the plasticity of material will raise, and we can obtain products that have higher relative density. 2. For different ratio of nano-carbon powder added, the best time delay to press is shorter, because the reactivity of green pellet raised and the reaction time reduced. 3. The increase of pressing time increasing would raise the relative density of material, but the raised degree will reach a limit value, even though the pressing time increased, the relative density will not be raised. 4. According to experiment results, the relative density of products will raise when the density of green pellets increase. The density of green pellet couldn’t increase anymore because of the limit of nano-scale powder. 5. For green pellet, the higher adding ratio of nano-scale carbon powder can reach to 90% theoretical density by lower compaction pressure. As compaction pressure increasing more, the relative density of TiC material can reach to 98%. The increase of compaction pressure increased the relative density of material, consequently. 6. Besides the amount of metal added would affect the relative density and hardness, both insufficient and overdose can’t reach the best condition of TiC/Me cermet. Dense TiC/Me cermet with metal content of 25 % wt can reach the highest relative density and hardness, therefore, proceed TiC/Me cermet with 25 % wt metal addition is excellent.

碩士
國立中興大學
環境工程學系所
107
In this study, Pt/g-C3N4/SrTiO3 photocatalyst was applied to decolorize dye and produce hydrogen simultaneously. Firstly, the effect of calcination temperatures of g-C3N4 on dye decolorization efficiency was investigated. The optimal calcination temperatures of g-C3N4 was combined with commercial SrTiO3 in different ratio, and the composite with the best ratio was decided by activity test. Then the g-C3N4/SrTiO3 photocatalyst was coated with Pt metal, and the effect of different TEOA concentration on activity test, determining the optimal operating condition. The results showed that the degree of crystallization and thermal condensation of g-C3N4 were influenced by calcination temperature greatly. In addition, different calcination temperature also affected optical properties and photocatalytic efficiency and the yield of g-C3N4. The combination of g-C3N4 and SrTiO3 could change the transfer path of photo-generated charge. The results indicated that the g-C3N4/SrTiO3 photocatalyst belonged to Z-scheme semiconductor in this study. To retard the charge recombination rate of the g-C3N4/SrTiO3, coating Pt on the surface of g-C3N4/SrTiO3. The results indicated that the AR1 decolorization was further improved from 19% to 99% after adding 5% TEOA into the reaction. Because the TEOA in the reaction solution could effectively retard the charge recombination rate of photocatalyst, resulting in increased photo-generated electron-hole pair separation, and more photo-generated electron could reduce oxygen to generate •O2—. According to the results of activity test, Pt/g-C3N4/SrTiO3 photocatalyst optimal AR1 decolorization rate and hydrogen production rate respectively achieved 93% and 470 μmol h-1 g-1 when the AR1 concentration and TEOA concentration were respectively controlled to 50 mg/L and 25%. when TEOA concentration was controlled at 5% TEOA, the hydrogen production rate reached 102 μmol h-1 g-1 per ml of TEOA, which has the highest hydrogen production efficiency.

Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 2007.
Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7348. Adviser: Steven C. Zimmerman. Includes bibliographical references (leaves 178-182). Available on microfilm from Pro Quest Information and Learning.

碩士
國立交通大學
材料科學與工程學系奈米科技碩博士班
104
Metastasis is associated with 90 % of cancer-related deaths and circulating tumor cells (CTCs) play an important role as an intermediate during the metastatic invasion. Targeting CTCs when they are transiting in the blood circulation could disrupt cancer dissemination and reduce the probability of cancer death. Herein, we introduce a magnetic photosensitive nanocarrier, gold nanocages-conjugated thiol-magnetic nanocarriers (GTMNCs) to trap and destroy cancer cells in situ in flow. Gold nanocages (AuNCs) are able to induce hyperthermia which results in cancer cells necrosis under 808 nm irradiation and sensitize singlet oxygen (1O2) formation to activate apoptosis program upon NIR illumination (940 nm LED, 915 nm laser). The temperature of the suspension of GTMNCs raised to more than 50 oC under 808 nm laser light. 1O2 phosphorescence emission and singlet oxygen sensor green (SOSG) fluorescent probe were used to confirm the 1O2 generation upon NIR illumination. As GTMNCs were functionalized with anti-epithelial cell adhesion molecule (EpCAM) antibody to specifically target mouse breast cancer cell (4T1), in vitro experiments demonstrated 9-fold increase in intracellular ROS levels by quantifying SOSG and dihydroethidium (DHE) fluorescence. Scavengers were also used as negative control. Cytotoxicity assay indicates that GTMNCs are high biocompatibility in dark until photoirradiation for performing photothermal therapy (PTT) and photodynamic therapy (PDT). Further magnetic enrichment of 4T1 cells and simultaneous photodestruction in the microfluidic channel using the GTMNCs proved a potential methodology of phototherapy for CTCs removal.

博士
高雄醫學大學
藥學研究所
98
The present study includes two parts. In the part I, a new β-cyclodextrin-HPLC method (β-CyD-HPLC) has been developed for the simultaneous determination and validation of β-lactam antibiotics and β-lactamase inhibitor in pharmaceutical products and biological samples. There are three subjects described as following: 1. An accurate and reproducible method for the simultaneous determination of ampicillin (AMP), sulbactam (SUL), and cefoperazone (CFP) in pharmaceutical formulations by using HPLC with β-CyD stationary phase was developed. It involved the use of the added tetraethylammonium acetate (TEAA) reagent, pH, and methanol as the significant parameters and the isothermal curve technique to find the optimal chromatographic condition. A high resolution and selectivity of analytes was obtained by running the mobile phase in methanol–5 mM TEAA buffer = 35:65 (v/v, pH 4.5) at 280 nm. This new HPLC method is simple, rapid, accurate, reproducible, and time-consuming for the routine assay of these components in sterilized H2O, saline, or 5% dextrose injection solutions. 2. A new β-CyD-HPLC method has been developed and validated for the simultaneous determination of ticarcillin (TIC) and clavulanic acid (CA) in pharmaceutical formulations. In experiment, using the Doehlert design to find the optimal chromatographic condition. The HPLC separation was achieved on a β-CyD column (Cyclobond I, 250×4.6 mm, 5 mm) with methanol–16 mM AA buffer=50:50 (v/v, pH 6.0) mobile phase at a flow rate of 0.8 mL/min. Detection was at 220 nm. The specificity, robustness, accuracy, and precision were performed to evaluate the method validation. Compared with the U.S. Pharmacopoeia method, the proposed method has the advantage of relatively low flow rate (0.8 mol/min) and short analysis time (<14 min) for routine assay. 3. A new β-CyD-HPLC method combined with Doehlert design has been developed for the simultaneous determination of piperacillin (PIP) and tazobactam (TAZ) in human plasma. Samples were pretreated with acetonitrile and dichloromethane. HPLC separation and quantitation were achieved on a β-CyD column (Cyclobond I, 250×4.6 mm, 5 mm) with running the mobile phase in methanol-12 mM TEAA buffer=50:50 (v/v, pH 3.4), UV detection at 225 nm, and a flow-rate of 0.8 mL/min. Compared with the four published procedures, the proposed method give a different chromatographic mechanism and isocratic mobile composition. It is considered that the proposed method is improved for the determination of PIP/TAZ in human biological samples by the lower flow rate (0.8 mL/min), acceptable pH value, and suitable retention time (<16 min). In the part II, a series of fluoroquinolonyl cephalosporin (FQ-cephalosporin) derivatives have been prepared to improve the antibacterial therapy. In the synthetic processes, the FQ moieties are firstly modified at N-1 position for decreasing its polarity. Then, each intermediate is activated by HONSu and coupled with cefaclor or cephalexin at C-11??-amino group to give FQ-cephalosporin derivatives. After separation, structures of products were identified by the UV, FT-IR, 1H-NMR, 1H-1H cosy, and FAB-MS spectral analyses. These derivatives were evaluated the in vitro antibacterial activity by the paper disk and MIC methods. The results indicate some facts: (1) In comparison with the parent drugs, compounds 5xa and 5xb are active against Gram-positive and Gram-negative bacteria; but all of 6xa~6xf derivatives are inferior to the starting material. (2) The FQ moieties that substituted at the C-11?? amino group of cefaclor are extended the activity against Pseudomonas aeruginosa strains. (3) The activity of substituents at C-3 position is Cl > CH3. (4) Compounds 5xa and 5xb cause extensive filamentation in cells of bacterial strains at the concentration near the half of MIC value. The in vivo preliminary test for acute toxicity was identified in mice with the selected candidates. It exhibites that compound 5xa causes the liver and kidney damage and blood urine; but 5xb shows much lower acute intraperitioneal toxicity as the parent drugs.

碩士
國立臺灣海洋大學
海洋生物研究所
95
Textile wastewaters were toxic and caused serious environmental problems. Previous studies had shown that decoloration of synthetic dyes, especially azo dyes can be achieved by using reduction of these dyes under anaerobic conditions. However, the intermediate,aromatic amines, produced from reduction of these dyes are generally not degraded and accumulated under anaerobic conditions, but could be degraded under aerobic conditions.Based on this metabolism, sequencial batch water system had been established to that waste water efferent containing azo dyes. In this study, we made immobilized beads with Shewanella sp. NTOU1 in an attempt to degrade three kinds of synthetic dyes(Azo, Triphenylmethane and Anthraquinone dyes)inside the beads which were under anaerobic conditions and degrade their intermediates(Aromatic amine) outside the beads which were under aerobic conditions. We expected to make simultaneous anaerobic and aerobic degradation of synthetic dyes in aerobic or microaerophilic environments. In optimum conditions, more than 90% of these dyes(100 ppm)could be removal in 24 hours. Benzidine, the intermediates could be degraded in next 10 days and the other intermediates Aniline, could be degraded after 28 hours. The degradtion product of RB-19, 1,4 - dihydroxy- 9,10 anthracenedione could be degraded after 10 days. These immobilized beads showd very high durability and stability. Compared with the two stage anaerobic-aerobic treatment system and normal wastewater treatment system, these immobilized cells have higher applicability and efficiency in textile wastewaters treatment.

碩士
國立臺灣大學
環境工程學研究所
93
It was verified that Ralstonia eutropha could accumulate a large amount of PHB in cells under the aerobic condition, and PHB is the raw material of plastic which can be decomposed by bacteria. So the aim of this study is to find out the growth condition and characteristic of PHB accumulation by Ralstonia eutropha in anoxic state, and then compare it with living under the aerobic and heterotrophic condition. It’s expected that Ralstonia eutropha can remove the nitrate from the waste water and the sludge which possesses high concentrated PHB can be reused. According to the reason above it’s worthy to do this research. All experiments proceeded in batch reactor. First of all, we provide hydrogen and discuss the growth of Ralstonia eutropha in anoxic condition without nitrate. And then we find out that nitrate is the only electronic acceptor of Ralstonia eutropha in anoxic condition. In that condition hydrogen can be the energy source of Ralstonia eutropha to promote the growth when the carbon lacks in the liquid. In both anoxic and aerobic conditions, Ralstonia eutropha begins to accumulate PHB in growth phase. Furthermore, reaching the highest content of PHB in cells is in the stationary phase. And then declining the PHB content in cells accompanys the coming of endogenous phase. In anoxic condition, i also researched PHB accumulation by Ralstonia eutropha in different C/N(5.10.20.25 and 30)、ammonia concentration(100 and 200 mgNH4-N/L) and nitrate concentration(292、397 and 485 mgNO3-N/L). The result reveals the difference of PHB accumulation in cells is obvious under C/N<20. The higher concentration of ammonia will accelerate the growth of Ralstonia eutropha and promote the PHB accumulation in cells apparently. There is also influence of enhancing the PHB accumulation in cells as the concentration of nitrate is promoting. In the aspect of aerobic condition, the different C/N against the influence of PHB accumulation by Ralstonia eutropha was performed. It was found that the condition of aerobic is similar to anoxic condition. The most important difference between the two conditions is that the PHB accumulation in aerobic condition is higher than that in anoxic condition. Maybe it is the faster growth and higher microorganism concentration that leads to the outcome.

碩士
文化大學
應用化學系
83
A procedure was developed for simultaneous determination of ODX ,CDX,TPC,FZD,DFZ,OXA,NAA,PMA,CLP,TMP,OMP,MRT,PYR,SMR,SMT,SMM, SDM and SQX in pork by HPLC with a photodiode array detector. The an- tibacterials was extracted with acetonitrile,following by liquid -liquid partition with n-hexane.HPLC carried out on a Puresil-TM C18 column using gradient elution with acetonitrile-0.2 phospho- ric acid.Recoveries were over 70% except in the case of DFZ.The detect limits were 0.01-0.02ppm, quantitation limit were 0.02- 0.07ppm.

碩士
中國醫藥大學
職業安全衛生學系碩士班
95
Objectives: This cross-sectional study was carried out to investigate effects of co-exposure to noise and organic solvents on workers’ resting blood pressure, liver functions, and kidney functions, and to explore the variation of ambulatory cardiovascular parameters. Method: We recruited 59 volunteers in a synthetic leather manufactoring factory as study subjects. Among them, 30 workers were selected to investigate co-exposure to noise and organic solvents on ambulatory cardiovascular parameters.We used the noise dosimeter, charcoal, and the GC-FID to measure personal exposure to noise and inhaled solvents during the working days.We classified workers to co-exposure to noise and organic solvents group, noise exposure group, organic solvents exposure group, and reference group by using the exposure index of mixture and the cumulate exposure index of mixture, respectively. We used the Dynapulse 5000A to measure workers’ ambulatory pulse pressure, mean arterial pressure, brachial arterial compliance, brachial arterial distensibility, and brachial arterial resistance. We used a self-administered questionnaire and the health-examination results to collect potential confounders. Multiple linear regression models were performed to investigate effects of different co-exposure levels on resting blood pressure, liver functions, and kidney functions. We also used linear mixed-effects regression models to estimate co-exposure effects on ambulatory cardiovascular parameters. Results: We found that co-exposure and organic solvents group (n=18), noise exposure group (n=9), and solvents exposure group (n=15) had the significantly higher mean value of resting systolic blood pressure than the reference group (n=17). Only the co-exposure group had the significant increment of resting diastolic blood pressure than the referece group. Both co-exposure and noise-exposure groups had the significantly higher mean value of serum creatinine than the reference group. Only the noise exposure group had the significantly higher mean value of serum uric acid compared to the reference group. However, there were no significantly differences on serum glutamic oxaloacetic transaminase and serum glutamic pyruvic transaminase between these four groups. Co-exposure to noise and solvents strengthened the increment of the pulse pressure but the decrement of the brachial arterial compliance during the working time, off-duty time, sleep time, and 24-hour average. Such co-exposure increased the mean arterial pressure but decreased the brachial artery distensibility only during the working time. Workers co-exposed to noise and solvents had the significant increments of the brachial arterial resitance during the off-duty and sleep periods. Conclusions: Co-exposure to noise and organic solvents may strengthen the increament of the resting blood pressure, serum creatinine levels, pluse pressure, mean arterial pressure, and brachial arterial resistance but the decrements of the brachial arterial compliance and brachial arterial distensibility. However, there were no significant effects on liver functions under such workplace.