Tesis sobre el tema "M-PTC"

Metallophilic (metal-metal) interactions are weak interactions between closed-shell (d10, s2) or pseudo-closed-shell (d8) metal cations. This type of interaction is generally believed to be responsible for various intriguing structures, luminescence, catalysis and magnetism. To gain a better understanding of metallophilic interactions, both experimental and computational investigations have been carried out in this thesis. Chapter 1 gave an up-to-date literature review on the definition, significance, and methods of estimating metallophilic interactions. The disputed nature and strength of metallophilic interactions encouraged us to further understand them. Chapter 2 focused on aurophilic interactions between AuI cations. Aurophilic interactions were observed in the solid state, but not well expressed in solution. Further experimental and computational results suggested that the strength of aurophilic interactions were weaker than electrostatic interactions. The nature of aurophilic interactions arose from orbital interactions rather than dispersion. Chapter 3 presented the study of metallophilic interactions between group 10 metal centres, including PtII-PtII, PdII-PdII and NiII-NiII. A series of cyclometalated square-planar metal complexes with different metals or substituents were prepared. PtII-PtII interactions were found to be stronger than PdII-PdII and NiII-NiII interactions. The dimerization constants of the Pt-containing complexes increased in line with increasing electron-withdrawing ability. Chapter 4 investigated the solvent-induced and thermally dependent colour changes of the Pt-containing complexes synthesised in chapter 3. Metallophilic interactions were proposed to be important in influencing the luminescence properties.

The diploma thesis is focused on the study of chemical reaction products in prebiotic atmospheres. The theoretical part deals with the main theories of composing the atmosphere of the early Earth, hypotheses of the origin of life and genetic code in the form of RNA, the atmosphere of the moon Titan and the basic characteristics of the gliding arc discharge, and the analytical techniques used in the diploma thesis. In the experimental part, study of products was carried out by experimental atmospheric simulations in a special stainless steel reactor in various mixtures of gases N2, CH4, CO2 and O2. The electrical discharge for atmospheric simulation was generated by an electrode configuration for the gliding arc discharge and glow discharge. Detection and identification of chemical reaction products was performed by Gas Chromatography with Mass Spectrometry (GC-MS) and Flame Ionization Detector (GC-FID), Testo 350 M/XL and Proton Transfer Reaction Mass Spectrometry (PTR-MS). A theoretical kinetic model was created to predict and confirm the detected products. During the experiments, the dependence of the product intensity on changes in the composition of the gaseous mixture and the applied value of the electric current was also observed.

Made available in DSpace on 2014-12-17T15:42:31Z (GMT). No. of bitstreams: 1 AnneMichelleGPS.pdf: 4577671 bytes, checksum: 19f54b9da1543ee4a1008ce93d607ec1 (MD5) Previous issue date: 2007-10-04<br>Bifunctional catalysts based on zircon oxide modified by tungsten (W = 10, 15 and 20 %) and by molybdenum oxide (Mo= 10, 15 e 20 %) containg platinum (Pt = 1%) were prepared by the polymeric precursor method. For comparison, catalysts the tungsten base was also prepared by the impregnation method. After calcinations at 600, 700 and 800 ?C, the catalysts were characterized by X-ray diffraction, fourier-transform infrared spectroscopy, thermogravimetric and differential thermal analysis, nitrogen adsorption and scanning electron microscopy. The profile of metals reduction was determined by temperature programmed reduction. The synthesized catalysts were tested in n-heptane isomerization. X-ray diffractogram of the Pt/WOx-ZrO2 and Pt/MoOx-ZrO2 catalysts revealed the presence of tetragonal ZrO2 and platinum metallic phases in all calcined samples. Diffraction peaks due WO3 and ZrO2 monoclinic also were observed in some samples of the Pt/WOx-ZrO2 catalysts. In the Pt/MoOx-ZrO2 catalysts also were observed diffraction peaks due ZrO2 monoclinic and Zr(MoO4)2 oxide. These phases contained on Pt/WOx-ZrO2 and Pt/MoOx-ZrO2 catalysts varied in accordance with the W or Mo loading and in accordance with the calcination temperature. The infrared spectra showed absorption bands due O-W-O and W=O bonds in the Pt/WOx-ZrO2 catalysts and due O-Mo-O, Mo=O and Mo-O bonds in the Pt/MoOx-ZrO2 catalysts. Specific surface area for Pt/WOx-ZrO2 catalysts varied from 30-160 m2 g-1 and for the Pt/MoOx-ZrO2 catalysts varied from 10-120 m2 g-1. The metals loading (W or Mo) and the calcination temperature influence directly in the specific surface area of the samples. The reduction profile of Pt/WOx-ZrO2 catalysts showed two peaks at lower temperatures, which are attributed to platinum reduction. The reduction of WOx species was evidenced by two reduction peak at high temperatures. In the case of Pt/MoOx-ZrO2 catalysts, the reduction profile showed three reduction events, which are attributed to reduction of MoOx species deposited on the support and in some samples one of the peak is related to the reduction of Zr(MoO4)2 oxide. Pt/WOx-ZrO2 catalysts were active in the n-heptane isomerization with high selectivity to 3-methyl-hexane, 2,3- dimethyl-pentane, 2-methyl-hexane among other branched hydrocarbons. The Pt/MoOx-ZrO2 catalysts practically didn't present activity for the n-heptane isomerization, generating mainly products originating from the catalytic cracking<br>Catalisadores bifuncionais a base de ?xido de zirc?nio modificado por ?xidos de tungst?nio (W = 10, 15 e 20 %) ou molibd?nio (Mo= 10, 15 e 20 %) contendo platina (Pt = 1 %) foram preparados pelo m?todo dos precursores polim?ricos. Por compara??o, catalisadores a base de tungst?nio tamb?m foram preparados pelo m?todo de impregna??o. Ap?s calcina??es a 600, 700 e 800 ?C, os catalisadores foram caracterizados por difra??o de raios-X, espectroscopia de absor??o na regi?o do infravermelho, an?lise termogravim?trica, an?lise t?rmica diferencial, adsor??o de nitrog?nio e microscopia eletr?nica de varredura. Os perfis de redu??o dos metais foram determinados por redu??o a temperatura programada. Os catalisadores sintetizados foram testados na isomeriza??o do n-heptano. Os difratogramas de raios-X dos catalisadores Pt/WOx-ZrO2 e Pt/MoOx-ZrO2 revelaram a presen?a do ZrO2 tetragonal e da platina met?lica em todas as amostras calcinadas. Picos de difra??o referentes ao WO3 e ao ZrO2 monocl?nico tamb?m foram observados em algumas das amostras dos catalisadores Pt/WOx-ZrO2. Nos catalisadores do tipo Pt/MoOx-ZrO2 tamb?m foram observados picos de difra??o referente ao ZrO2 monocl?nico e ao ?xido Zr(MoO4)2. O aparecimento destas outras fases contidas nos catalisadores Pt/WOx-ZrO2 e Pt/MoOx-ZrO2 variaram de acordo com o teor de W ou Mo e de acordo com a temperatura de calcina??o. Os espectros de absor??o na regi?o do infravermelho exibiram bandas de absor??o referentes as liga??es O-W-O e W=O nos catalisadores Pt/WOx-ZrO2 e referentes as liga??es O-Mo-O, Mo=O e Mo-O nos catalisadores Pt/MoOx-ZrO2. A ?rea superficial espec?fica dos catalisadores Pt/WOx-ZrO2 variou de 30-160 m2 g-1 e para os catalisadores do tipo Pt/MoOx-ZrO2 variou de 10-120 m2 g-1. O teor de metais (W ou Mo) e a temperatura de calcina??o exercem uma influ?ncia direta no valor da ?rea superficial espec?fica das amostras. Os perfis de redu??o dos catalisadores Pt/WOx-ZrO2 exibiram dois picos a baixas temperaturas, os quais s?o atribu?dos a redu??o da platina. A redu??o das esp?cies WOx foi evidenciada por dois picos de redu??o a altas temperaturas. No caso dos catalisadores Pt/MoOx-ZrO2, os perfis de redu??o mostram tr?s eventos de redu??o, os quais s?o atribu?dos a redu??o das esp?cies MoOx depositadas no suporte e em algumas amostras um dos picos ? relacionado com a redu??o do ?xido Zr(MoO4)2. Os catalisadores Pt/WOx-ZrO2 foram ativos para a isomeriza??o do n-heptano com alta seletividade a 3-metil-hexano, 2,3-dimetil-pentano e 2-metil-hexano entre outros hidrocarbonetos ramificados. Os catalisadores Pt/MoOx- ZrO2 praticamente n?o apresentaram atividade para a isomeriza??o do n-heptano, gerando principalmente produtos oriundos do craqueamento catalitico

Catalisadores bifuncionais a base de óxido de zircônio modificado por óxidos de tungstênio (W = 10, 15 e 20 %) ou molibdênio (Mo= 10, 15 e 20 %) contendo platina (Pt = 1 %) foram preparados pelo método dos precursores poliméricos. Por comparação, catalisadores a base de tungstênio também foram preparados pelo método de impregnação. Após calcinações a 600, 700 e 800 ºC, os catalisadores foram caracterizados por difração de raios-X, espectroscopia de absorção na região do infravermelho, análise termogravimétrica, análise térmica diferencial, adsorção de nitrogênio e microscopia eletrônica de varredura. Os perfis de redução dos metais foram determinados por redução a temperatura programada. Os catalisadores sintetizados foram testados na isomerização do n-heptano. Os difratogramas de raios-X dos catalisadores Pt/WOx-ZrO2 e Pt/MoOx-ZrO2 revelaram a presença do ZrO2 tetragonal e da platina metálica em todas as amostras calcinadas. Picos de difração referentes ao WO3 e ao ZrO2 monoclínico também foram observados em algumas das amostras dos catalisadores Pt/WOx-ZrO2. Nos catalisadores do tipo Pt/MoOx-ZrO2 também foram observados picos de difração referente ao ZrO2 monoclínico e ao óxido Zr(MoO4)2. O aparecimento destas outras fases contidas nos catalisadores Pt/WOx-ZrO2 e Pt/MoOx- ZrO2 variaram de acordo com o teor de W ou Mo e de acordo com a temperatura de calcinação. Os espectros de absorção na região do infravermelho exibiram bandas de absorção referentes as ligações O-W-O e W=O nos catalisadores Pt/WOx-ZrO2 e referentes as ligações O-Mo-O, Mo=O e Mo-O nos catalisadores Pt/MoOx-ZrO2. A área superficial específica dos catalisadores Pt/WOx-ZrO2 variou de 30-160 m2 g-1 e para os catalisadores do tipo Pt/MoOx-ZrO2 variou de 10-120 m2 g-1. O teor de metais (W ou Mo) e a temperatura de calcinação exercem uma influência direta no valor da área superficial específica das amostras. Os perfis de redução dos catalisadores Pt/WOx-ZrO2 exibiram dois picos a baixas temperaturas, os quais são atribuídos a redução da platina. A redução das espécies WOx foi evidenciada por dois picos de redução a altas temperaturas. No caso dos catalisadores Pt/MoOx-ZrO2, os perfis de redução mostram três eventos de redução, os quais são atribuídos a redução das espécies MoOx depositadas no suporte e em algumas amostras um dos picos é relacionado com a redução do óxido Zr(MoO4)2. Os catalisadores Pt/WOx-ZrO2 foram ativos para a isomerização do n-heptano com alta seletividade a 3-metil-hexano, 2,3-dimetil-pentano e 2-metil-hexano entre outros hidrocarbonetos ramificados. Os catalisadores Pt/MoOx- ZrO2 praticamente não apresentaram atividade para a isomerização do n-heptano, gerando principalmente produtos oriundos do craqueamento catalitico. _________________________________________________________________________________________ ABSTRACT: Bifunctional catalysts based on zircon oxide modified by tungsten (W = 10, 15 and 20 %) and by molybdenum oxide (Mo= 10, 15 e 20 %) containg platinum (Pt = 1%) were prepared by the polymeric precursor method. For comparison, catalysts the tungsten base was also prepared by the impregnation method. After calcinations at 600, 700 and 800 ºC, the catalysts were characterized by X-ray diffraction, fourier-transform infrared spectroscopy, thermogravimetric and differential thermal analysis, nitrogen adsorption and scanning electron microscopy. The profile of metals reduction was determined by temperature programmed reduction. The synthesized catalysts were tested in n-heptane isomerization. X-ray diffractogram of the Pt/WOx-ZrO2 and Pt/MoOx-ZrO2 catalysts revealed the presence of tetragonal ZrO2 and platinum metallic phases in all calcined samples. Diffraction peaks due WO3 and ZrO2 monoclinic also were observed in some samples of the Pt/WOx-ZrO2 catalysts. In the Pt/MoOx-ZrO2 catalysts also were observed diffraction peaks due ZrO2 monoclinic and Zr(MoO4)2 oxide. These phases contained on Pt/WOx-ZrO2 and Pt/MoOx-ZrO2 catalysts varied in accordance with the W or Mo loading and in accordance with the calcination temperature. The infrared spectra showed absorption bands due O-W-O and W=O bonds in the Pt/WOx-ZrO2 catalysts and due O-Mo-O, Mo=O and Mo-O bonds in the Pt/MoOx-ZrO2 catalysts. Specific surface area for Pt/WOx-ZrO2 catalysts varied from 30-160 m2 g-1 and for the Pt/MoOx-ZrO2 catalysts varied from 10-120 m2 g-1. The metals loading (W or Mo) and the calcination temperature influence directly in the specific surface area of the samples. The reduction profile of Pt/WOx-ZrO2 catalysts showed two peaks at lower temperatures, which are attributed to platinum reduction. The reduction of WOx species was evidenced by two reduction peak at high temperatures. In the case of Pt/MoOx-ZrO2 catalysts, the reduction profile showed three reduction events, which are attributed to reduction of MoOx species deposited on the support and in some samples one of the peak is related to the reduction of Zr(MoO4)2 oxide. Pt/WOx-ZrO2 catalysts were active in the n-heptane isomerization with high selectivity to 3-methyl-hexane, 2,3- dimethyl-pentane, 2-methyl-hexane among other branched hydrocarbons. The Pt/MoOx-ZrO2 catalysts practically didn't present activity for the n-heptane isomerization, generating mainly products originating from the catalytic cracking.

In questa tesi di dottorato, viene presentata, per la prima volta, una caratterizzazione a livello molecolare del dominio C-terminale della proteina umana OSCP in soluzione, tramite l’impiego sinergico di diverse tecniche strutturali avanzate come l’NMR, il Bio-SAXS e l’ITC. Successivamente, grazie alle informazioni raccolte anche per il dominio umano N-terminale, è stato possibile porre le basi per una prima indagine biofisica dell’intera subunità in soluzione, comprendendone nuove ed inaspettate proprietà strutturali che aiuteranno a fare luce sugli emergenti ruoli terapeutici di OSCP, anche in qualità di subunità regolatrice del m-PTP. Le nuove informazioni raccolte su OSCP hanno poi permesso di effettuare i primi studi a livello molecolare su due processi di interazione proteina-proteina connessi con la regolazione del m-PTP e con le patologie cellulari ad esso correlate. Il primo riguarda un nuovo legame fra OSCP e la prima isoforma dell’inibitore mitocondriale dell’ATP sintasi IF1-1, ad oggi noto solamente per l’azione inibitrice dell’attività idrolasica del complesso V in condizioni ipossiche, attraverso il legame con la porzione catalitica F1. La nuova interazione tra OSCP e IF1-1 è stata trovata in alcuni modelli cellulari tumorali, nei quali l’inibitore risulta essere particolarmente sovra-espresso, in condizioni in cui l’enzima sintetizza ATP (fosforilazione ossidativa). Questo nuovo legame non influenza l’attività enzimatica dell’ATP sintasi ma inibisce l’apoptosi cellulare, nello specifico attraverso un silenziamento del m-PTP, aiutando così la cellula tumorale a raggiungere una condizione di apoptosi-resistenza e immortalità. Il secondo processo, invece, coinvolge la nota interazione fra OSCP e CypD, finora mai studiata a livello molecolare. La nostra indagine ha permesso di portare alla luce nuove, seppur preliminari, informazioni riguardo il meccanismo strutturale di questo legame proteina-proteina che resta, ad oggi, uno dei pochi processi molecolari riconosciuti dal mondo scientifico come direttamente coinvolto nell’apertura del m-PTP. Viene inoltre riportata la caratterizzazione strutturale dell’interazione fra la chinasi umana CK2α (subunità catalitica) e un nuovo poliossometallato a base di rutenio. Attraverso i risultati sperimentali ottenuti, è stato proposto un interessante meccanismo di inibizione dell’enzima, la cui attività catalitica è particolarmente importante per i meccanismi di proliferazione sfruttati delle cellule tumorali.<br>In this PhD work, it is provided the first characterization at a molecular level of the C-terminal domain of the human OSCP in solution, by a synergic use of different and advanced structural techniques as NMR, Bio-SAXS and ITC. Thanks to the information collected also for the human N-terminal domain, it has been possible to perform a preliminary investigation of the whole subunit in solution, understanding new and unexpected structural proprieties that will help to elucidate the emerging therapeutic roles of the OSCP, even as a regulatory subunit of the m-PTP. The new information about the OSCP allowed us to study for the first time two protein-protein interaction processes at a molecular level, which are involved in the m-PTP regulation and its related pathologies. The first one is the novel binding event between the OSCP and the first isoform of the ATPase inhibitor IF1-1 that is known for its inhibitory action against the complex V hydrolytic activity in anoxia, through the binding within the F1 catalytic module. The new interaction between the OSCP and IF1-1 was detected in some tumor cell models, where the inhibitor is overexpressed, during mitochondrial respiration and ATP synthesis (oxidative phosphorylation). This novel binding event does not affect the ATP synthase catalysis but it prevents the apoptosis, specifically through the m-PTP desensitization, helping in this way the cancer cell to achieve an apoptosis-resistant phenotype and immortality. The second binding process regards the well known interaction between the OSCP and CypD which has never been studied at a molecular level. Our investigation allowed to elucidate new, despite preliminary, aspects about the structural mechanisms of this protein-protein binding event that remains, nowadays, one of the few molecular processes accepted form the scientific community as directly involved into the m-PTP sensitization. It is also reported, as a side project, the structural characterization of the interaction between human protein kinase CK2α (catalytic subunit) and a novel ruthenium-based polyoxometalate, which provides an interesting inhibition mechanism against the cancer-related CK2, at a molecular level.

Use of solar thermal energy in residential and industrial applications has to be sustained to reduce the concentration of greenhouse gas in atmosphere due to the exploitation of fossil fuels in producing energy. In this context, the renewable energies play an important role. The energy request in industrial and residential sector involves a noticeable fraction (more than 50%) of the total requested supply for human activities. Concentrating collectors could be the right technology to produce heat at medium temperature (between 85 and 250°C) to provide thermal energy to users with high consumption rates and low-temperature heat demand like domestic hot water and space heating in addition to the industrial process heat applications. Thus, in this study UF-RT01 receiver (University of Florence Receiver Tube 01) of small size parabolic trough collector called m-PTC were investigated experimentally by indoor and outdoor tests and computationally by 3D heat transfer FEM model. The m-PTC suitable to be integrated in the roof of industrial environments where the space for installation of solar collectors is in general limited and the heat demand temperature is below than 200°C. The UF-RT01 receiver has a specific design, being formed by two coaxial tubes so that the fluid inlet and output are at the same side. It was properly developed to scale the PTC technology toward smaller size (chord length from 6-8 meters to around 0.5 m): the purpose is the installation in urban context and the application in industrial process. The outer absorber tube is made of steel and has a diameter of 10 mm (1 mm thickness) for a length of 1860 mm; the smaller coaxial tube is made of steel and has an internal diameter of 6 mm (0.5 mm thickness). Furthermore, a selective coating has been selected to reduce the emission in infrared range and increase the energy absorption in solar spectral range. Inside, a vacuum level is fixed at 10-4 mbar to reduce the heat losses to the radiative ones. In order to study the thermal losses of the receiver, two different indoor test stand have been realized. The thermal loss measurement is set up under indoor test without Sun irradiance, imposing a controlled internal heating. This process is based on the Joule effect, feeding electric heaters with current to obtain a steady state condition at different reference temperatures. In preliminary test stand by removing the inner coaxial steel tube, two nickel-chrome wire heaters are inserted along the length of absorber tube. An additional external heater is also placed before the Kovar part to meet the adiabatic condition and minimizing the temperature gradient. The UF-RT01 has been analyzed experimentally and performances are evaluated as a function of different operating temperatures, reaching up to 180°C. A maximum value for heat loss amounts at about 24 W when ΔT is 161°C (receiver average temperature of 180°C). In order to obtain more uniformity of temperature along the absorber tube the second test set up has been developed for thermal loss measurement and instead of nickel-chrome wire heater, an industrial cartridge heater made of resistance wire (NiCr20/80) as a core covered with stainless steel 304 as a sleeve (sheath) has been used. Three different tube from same type (UF-RT01) have been tested in the range of interest and the procedure was repeated for about 150 cases. In comparison to preliminary test stand, results showed more uniformity in temperature distribution along the tube. A maximum value of 17.89 W is found when ΔT is 163°C (receiver average temperature of 190°C). In order to achieve production assurance and have more clear vision about the results due to the different results obtained from test on RT03 in comparison to the RT01 and RT02 with higher thermal loss, new tests have been conducted on additional tubes. Similar setup and test procedure have been conducted in order to evaluate the uniformity of temperature along the tube and estimate the heating supplier parameters in additional tubes. Seven different tube from same type have been tested and labeled as RT04-RT10. Results from tests on RT01 and RT02 are in accordance with new results obtained from heat loss test on RT04-RT10. Therefore, the different results related to the RT03 are to be expected as a result of variation in production quality by manufacturer of receiver tube. The Finite Element Method (FEM) has been used in order to predict the thermal performance and analyze the relevant physical characteristics of the receiver tube (specially the value of emissivity at higher temperature). Heat transfer model using FEM simulation method has been realized with Comsol Multiphysics software. An adaptive mesh refinement (AMR) with different mesh configurations has been conducted in order to increase storage and computational savings. By using a parametric sweep to vary the maximum element size, the model solved using meshes with different mesh density in order to study how it affects the solution. The heat transfer model is able to precisely predict the heat losses at low temperature of the absorber tube with constant value of emissivity reported by manufacturer. The estimation of emissivity at the higher temperature obtained by solving the model with various emissivity values for each test at specific input power until the average temperature inside the absorber tube obtained by simulation were in agreement with experimental value. The obtained emissivity function has been used in model in order to solve the model for various input power values and the results showed that the model and emissivity function are able to predict the thermal loss with high accuracy. In order to perform the out-door test according the designed and assembled test rig platform at first phase has been slightly modified to reduce the heat losses and reach stable inlet temperature . The reliability of implemented test bench and output power and efficiency of a novel small size parabolic trough collector have been evaluated by preliminary test. For this purpose an out-door tests at ambient temperature on the designed small size PTC test rig is carried out during clear sky day. Furthermore, the peak optical efficiency test has been conducted based on introduced requirements at quasi-steady condition. The general point of the outdoor efficiency test is extracting the efficiency curve of the collector for normal incidence based on the efficiency curve coefficients. 24 tests have been done under various inlet temperature and irradiance under clear sky condition and the exemplary performance measurement data for present research stems from 153 experimental points. The preliminary out-door experimental test on the collectors showed that the test rig meets the initial design expectations in order to control the system in stable condition. The peak optical efficiency test has been conducted at quasi-steady condition and the average peak optical efficiency of the collector is 61.8% with total absolute error of 1.4%. With regard to the peak optical efficiency and for assuring that experimental results from the outdoor testing are valid, a cross check with the efficiency curve of the collector by weighted least squares (WLS) fitting shows almost similar values. The obtained value for peak optical efficiency from efficiency curve is 62.1%. Efficiency measurement of solar collector have been conducted from inlet temperature of 28 °C up to 123°C for various DNI values. A Maximum of 63.1% for thermal efficiency is found when the inlet temperature is 28.41°C and a minimum of 54.6% corresponds at 122.90°C. The total standard absolute uncertainty of thermal efficiency for test at inlet temperature of 28.41°C and 122.90°C are 0.7% and 0.8%, respectively. The efficiency curve of the collector by WLS fitting were also obtained from outdoor test results.

碩士<br>國立中興大學<br>通訊工程研究所<br>97<br>A modified PTS algorithm by partitioning an OFDM block into non-disjoint OFDM sub-blocks is presented in this paper for PAPR reduction of M-QAM OFDM signals. Since a 16-QAM constellation can be written as sum of two QPSK sets, respectively four BPSK sets, a non-disjoint sub-block partition of the 16-QAM OFDM block is obtained by applying two different disjoint partitions on QPSK OFDM blocks, respectively four different disjoint partitions on BPSK OFDM blocks. Compared to a disjoint sub-block partition in conventional PTS, numerical results show that themodified PTS with a non-disjoint partition achieves an improvement of PAPR reduction and BER performance for interleaved, adjacent, and random partitioning schemes.

碩士<br>國立中興大學<br>化學系所<br>101<br>We use benzyl bromoacetate as 2-N substituted alkylation to react with N-confused porphyrin to afford 2-aza-2-benzyloxycarbonylmethyl-5,10,15,20-tetraphenyl-21-carbaporphyrin (2-NCH2COOCH2C6H5NCTPPH) (2). After 2-N substituted alkylation, we use Ni(OAc)2∙4H2O, PdCl2, PtCl2, MnBr2 and CoCl2∙6H2O to react seperately with 2-NCH2COOCH2C6H5NCTPPH (2) to get six NCP metal complexes, Ni(2-NCH2COOCH2C6H5NCTPP) (3), Pd(2-NCH2COOCH2C6H5NCTPP) (4), Pt(2-NCH2COOCH2C6H5NCTPP) (5), Mn(2-NCH2COOCH2C6H5NCTPP)Br (6), Co(2-NCH2COOCH2C6H5-21-CH2C6H5NCTPP)Cl (7) and Co(2-NCH2COOCH2C6H5-21-CH2C6H4CH3NCTPP)Cl (8). Appling X-ray single-crystal diffractometer, NMR spectrometer, EPR spectrometer, superconducting quantum interference device and et cetera to study the crystal structures of NCP metal complexes and various microcosmic physical chemistry property.

碩士<br>淡江大學<br>國際商學碩士在職專班<br>100<br>The study of business management is often focused through analysis of historical successful and failure management cases. With the help of theoretical business models, it would help the company to improve the business management towards better results. However, the case study of remodeling business through accumulating core business essentials and flexibility of organizational structure from merger and acquisition are much less explored. From The acquisition of Compaq 10 years ago and recently announced to spin off PC organization. The study of HP (Hewlett-Packard) merger and acquisition can be helped with 2 concepts, that is, game theory and theoretical business structure and strategy, and to see whether this horizontal merger is workable from economical and strategical point of view. This thesis focuses on the method of acquisition of HP to reconstruct better picture of the details before and after acquisition. This is to see if the acquisition decision was due to mis-judged of business trend and operation, which caused impulsive merging action without proper plans and lack of long term investment insight. The following definitions, theories and study cases of the reference documents would help to understand on the main topic and direction of this thesis. This thesis will provide relative and connective questions and suggestions for the decisions before and after merger or acquisition. The aim is to provide suggestion and information with best benefit during horizontal merger or acquisition in shortest period of time for the companies which have similar aspects (or competition in the same market).

碩士<br>國立中央大學<br>材料科學與工程研究所<br>101<br>Controlling the morphology of Pt nanostructures can provide a great opportunity to improve their catalytic properties and increase their activity on a mass basis. In this study, highly effective carbon supported PtM (M= Au, Pd, or Cu) nanoparticles (NPs), Pt and PtM nanorods (NRs) prepared by formic acid method (FAM) are studied for their activity and durability toward oxygen reduction reaction (ORR). The structures, surface compositions, chemical compositions, morphologies, electrochemical properties and local structural parameters of prepared catalysts are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma-atomic emission spectrometer (ICP-AES), high resolution transmission electron microscopy (HRTEM), rotating disk electrode (RDE) technique and X-ray absorption spectroscopy (XAS), respectively. The study is divided into three parts. In the first part, the 45 wt% PtM NPs are prepared by FAM successfully. The ORR activity and long-term durability of the PtM NPs is better than that of the Pt/C after 1000th potential cycles of accelerated durability test (ADT), especially PtAu NPs. The promotion of ORR performance is attributed to the modified electronic structure of the surface Pt and oxophilicity through the underlying Au sublayer. In the second part, the 45 wt% Pt and PtM NRs catalysts with an average diameter of 3 nm and length of 10-20 nm are prepared by FAM. The number of unoccupied d-states (hTs) extracted from Pt LIII and LII –edge of XAS spectra show that PtCu and PtPd NRs have lower unfilled Pt d-states, indicating more d-band electrons transfer from the metal to Pt and a decrease of the adsorption strength of oxygenated adsorbates. The as-prepared Pt and PtM NRs have significantly enhanced ORR activity with an electrons transfer number per oxygen molecule of more than 3.8. Besides, after ADT of 1000 cycles, PtCu NRs display a mass activity of 34.4 mA cm−2 mg-1 Pt, which is nearly 2.2 times higher than that of commercial Pt/C. Thus, these results lead to the conclusion that the promotional effect of Pt and PtM NRs may be attributed to the 1D morphology, favorably enhancing the electrochemical activity and stability of ORR. In the third part, the LSV results exhibit that the current density of PtCu NRs and Pt/C in HClO4 is about 3.0 and 1.5 times higher than that in H2SO4 because strongly adsorbed sulfate (or bisulfate) anions block the ORR active sites on Pt, especially on Pt (111) surface.

碩士<br>國立中央大學<br>材料科學與工程研究所<br>102<br>Developing the one-dimensional (1-D) Pt-based nanomaterials with graphene support can provide a great opportunity to improve their catalytic activity and durability. In this study, carbon or graphene supported Pt and PtM (M= Cu or Pd) nanorods (NRs) are prepared by the formic acid method (FAM). The structures, surface compositions, chemical compositions, morphologies, electrochemical properties and the number of unfilled d-state (H Ts ) of prepared catalysts are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma-atomic emission spectrometer (ICP-AES), high resolution transmission electron microscopy (HRTEM), rotating disk electrode (RDE) technique and X-ray absorption spectroscopy (XAS), respectively. The study is divided into two parts. In the first part, carbon-supported Pt and PtM NRs with different ratios are successfully prepared by FAM. The H Ts value extracted from X-ray absorption near edge spectroscopy (XANES) can be used to measure the d-band vacancies of Pt, which is strongly related to their ORR performance. The HTs value of Pt nanoparticles (NPs) is decreased due to the formation of NRs, and further decreased due to the alloying with different metals. For Pt3Pd NRs, the H Ts value is as low as 0.3056, suggesting that they have lower unfilled Pt d-states, and more d-band electrons transfer from Pd to Pt, leading to higher ORR activities than Pt/C. Moreover, the specific activity (SA 085-1000 ) value of the Pt3Pd after accelerated durability test(ADT) is higher than that of the Pt/C. These results may be owing to the electronic modification e ff ect from Pd and 1-D structures synergistically. In the second part, the graphene-supported Pt and PtPd NRs catalysts are prepared by FAM. XRD analysis has shown that through alloying with Pd and using graphene support for the Pt NRs (G-PtPd), the growth of (111) and (220) planes is promoted. H Ts of Pt NRs is further decreased due to the use of graphene support and alloying. Among all catalysts, G-PtPd shows the lowest H Ts value, which is 0.295. Moreover, G-PtPd has the highest activity and durability among all catalysts in which their specific and mass activities after ADT is about 6.5 and 2.7 times higher than those of carbon-supported Pt NPs, confirming that the electronic modification effect from Pd and graphene-metal interaction can be promoted synergistically for Pt NRs.

碩士<br>國立成功大學<br>化學系碩博士班<br>94<br>We studies of CO [2p] and LP(C) [5s] in group 10 transition-metal carbonyl complexes M(CO)42+、M(CO)3Lq [M=Ni2+, Pd2+, Pt2+；L＝F-, Cl-, Br-, H2O, CN-, NH3, NMe3, PMe3, P(OMe)3, PF3] by NBO analysis. This is a subsequent study to cis 5s(CO)2p(CO) hyperconjugation observed in 6B M(CO)6. We have found this BOBO donor-acceptor interaction, in the order 3d>>5d>4d similar to that found in M(CO)6, but considerably smaller than in 6B M(CO)6. Therefore, the net result of 2p population originally in the order 3d<4d<5d . We have then evaluated the term “trns-influence” in M(CO)3L [M=Ni2+, Pd2+, Pt2+；L＝F-, Cl-, Br-, H2O, CN-, NH3, NMe3, PMe3, P(OMe)3]by analyzing [5σ]. The well-known sequence, P(OMe)3＞PMe3＞CN-＞Br-＞Cl-＞F-＞NMe3＞NH3＞H2O , has been found and supplies another merit of the NBO method . More significantly, the antibonding BO, s*P-Y plays a more important role than the 3d-AO of P-atom. The p-accepting capabilities of PF3, P(OMe)3, PMe3, depend on the polarized extent of PY (Y= C, O or F) bonding and the 3p-atomic orbital characters. Based on this rehybridization argument, the sequence of p-back-donation strengths is PF3＞P(OMe)3 > PMe3.

碩士<br>國立臺灣科技大學<br>化學工程系<br>100<br>Proton exchange membrane fuel cells (PEMFCs) have been regarded as potential energy-conversion power devices owing to the advantages of not only using renewable and eco-friendly energy sources such as hydrogen or methanol as fuels, but also highly efficient. However, majority of the current PEMFCs rely on the use of noble metals (e.g., Pt, Ru) supported on activated carbons as electrocatalysts at both anode and cathode, which put some limits in scale-up production and feasibility for commercialization in terms of cost-effective view point. Thus, considering electrocatalysts for PEMFCs, R&D directs toward utilization of lesser noble metals or metal-free catalyst is a demanding task. In view of the anodic electrocatalyst for direct methanol fuel cells (DMFCs), utilization of Pt-based bifunctional catalyst was found to overcome the critical issue of CO-poisoning. It has been shown that by introducing a secondary noble metal (e.g., Ru), the structural, electronic, and chemical properties of the catalyst may be greatly enhanced. As a result, the supported PtRu/C catalyst shows improve stability and tolerance over CO-poisoning, and hence, a superior electrocatalytic activity over methanol oxidation reaction (MOR). Nevertheless, from the viewpoints of cost-effectiveness of the membrane electrode assembly (MEA) and overall performance of the PEMFC, further reducing the MEA production cost while maintain a satisfactory MOR activity at anode should be beneficial for both fundamental research and potential industrial applications. As such, the objectives of this research is to develop facile syntheses of Pt-based bifunctional PtM (M = Ru, Fe, Mo, Sn) alloy electrocatalysts supported on ordered mesoporous carbons (OMCs) and to explore their stability and electrocatalytic performances during MOR. In continuation of our previous research endeavor, we report herein the synthesis of bifunctional Pt-M (M = Ru, Fe, Mo, Sn) electrocatalysts. The syntheses were carried out by using furfuryl alcohol and trimethylbenzene as the primary carbon sources, acetylacetonate organometallic compounds as the metallic precursors and the secondary carbon sources, and SBA-15 as the hard template, followed by carbonization under oxygen-free environment at elevated temperature (800 oC) and subsequent removal of the silica template. The structures, physicochemical properties, and electrocatalytic activities of the resultant PtM-OMCs were characterized by a variety of different analytical and spectroscopic techniques, such as H2 and CO chemisorption, N2 adsorption/desorption isotherm measurements, powdered x-ray diffraction (PXRD), transmission microscopy (TEM), x-ray photoelectron spectroscopy (XPS), and inductive-coupled plasma mass spectroscopy (ICP-MS). Moreover, their electrocatalytic performances were evaluated by chronoamperometry (CA), and cyclic voltammetry (CV) measurements. It was found that the PtM-OMC supported alloy catalysts so obtained all possess high specific surface areas (> 1000 m2/g), uniform pore size distributions (ca. 3 nm), and highly dispersed nano-scale average particle sizes (2 ~ 3 nm). Further electrocatalytic tests revealed that the MOR activities of these electrocatalysts follow the order: PtRu-OMC > PtMo-OMC ~ PtFe-OMC >> PtSn-OMC. Although the PtRu-OMC catalyst exhibited the anticipated highest activity over the PtM-OMCs, it is less compelling in terms of cost over the observed current density per unit metal. It is noteworthy that the PtFe-OMC catalyst, which revealed a satisfactory electrocatalytic performance over the other PtM-OMCs during MOR, shows perspective industrial application as anodic electrocatalyst for DMFC.

碩士<br>國立中興大學<br>化學系所<br>101<br>We use p-(trifluoromethyl)benzyl bromide to proceed N-alkylation with N-confused prophyrin that synthesis 2-aza-2-[ p-(trifluoromethyl)benzyl]-5,10,15,20-tetraphenyl N-confused prophyin,we called as 2-NCH2-p-C6H4CF3NCTPPH(2). Secondly ,we use Ni ,Pd ,Pt and Cu as metal reagent to get four complexes: Ni(2-NCH2-p-C6H4CF3NCTPP)(3)；Pd(2-NCH2-p-C6H4CF3NCTPP)(4)；Pt(2-NCH2-p-C6H4CF3NCTPP)(5) and Cu(2-NCH2-p-C6H4CF3NCTPP O)(6). Then we use X-ray Single-Crystal Diffractometer ,NMR spectroscopy and EPR spectroscopy ,etc. ,to determine the crystal structure and to analyze the molecular characteristics.

碩士<br>國立中興大學<br>化學系所<br>101<br>We use 4-Cyanobenzyl bromide as alkylation reagent to react with N-confsed porphyrin to get 2-NCH2-p-C6H4-CNNCTPPH(2)，and using Ni、Pt、Cu、Co as metal reagent to get Ni(2-NCH2-p-C6H4-CNNCTPP) (3)、Pt(2-NCH2-p-C6H4-CNNCTPP)(4)、Cu(2-NCH2-p-C6H4-CNNCTPPO) (5) and Co(2-NCH2-p-C6H4-CN-21-CH2C6H4CH3NCTPP)(6)。 To develop the correlations between δ13C [C(3)], δ1H [H(3)] and dipolar (canonical form II) in 3 and4, this work also thoroughly examines the 13C and 1H NMR of N+ = CH(Ar) fragment on metal complexes of 2-N substituted N-confused porphyrin。The shape of195Pt satellite lines in the 1H spectra vary with the magnetic field owing to CSA relaxation of 195Pt。

碩士<br>國立中興大學<br>化學系所<br>102<br>We use isopropyl benzyl bromide as alkylation reagent to react with N-confused porphyrin (NCP) to afford 2-aza-2-[p-(isopropyl)benzyl]-5,10,15,20-tetraphenyl-21-carbaporphyrin [2-NCH2-p-C6H4-isoC3H7NCTPPH; 2]. Then we use Ni(OAc)2∙4H2O, PdCl2, PtCl2 and CoCl2∙6H2O as metal source to react with (2) seperately to get four NCP metal complexes: (2-aza-2-[p-(isopropyl)benzyl]-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′,N′′) nickel(II) [Ni(2-NCH2-p-C6H4-isoC3H7NCTPP); 3], (2-aza-2-[p-(isopropyl)benzyl]-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′,N′′) palladium(II) [Pd(2-NCH2-p-C6H4-isoC3H7NCTPP); 4], (2-aza-2-[p-(isopropyl)benzyl]-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N′,N′′) platinum(II) [Pt(2-NCH2-p-C6H4-isoC3H7NCTPP); 5], and chloro(2-aza-2-[p-(isopropyl)benzyl]-5,10,15,20-tetraphenyl-21- p-xylyl-21-carbaporphyrinato-N,N′,N′′) cobalt(II) [Co(2-NCH2-p-C6H4-isoC3H7-21-CH2-p-C6H4CH3-NCTPP)Cl; 6]. 　　Appling X-ray single-crystal diffractometer, Nuclear magnetic resonance spectrometer, Electron paramagnetic resonance spectrometer, Superconducting quantum interference device magnetometer, UV-visible spectrophotometer, UV-visible-NIR spectrophotometer, Elemental analyzer, Mass spectrometer to characterize and study the crystal structures of NCP metal complexes and their physical chemistry property. 　　The crystal structures of free base (2), diamagnetic complexes (3), (4), (5) and paramagnetic complex (6) were determined. The coordination sphere around Ni2+, Pd2+ and Pt2+ ions in 3 - 5 are distorted square planar (DSP), whereas for Co2+ in 6, it is distorted tetrahedron (DT). The effective g value, geff = [gx(eff), gy(eff), gz(eff)] = [1.92, 3.73, 6.18] measured from the perpendicular polarization of X-band EPR spectra for 6 in toluene at 4 K is consistent with a 4A2(F) ground term for a high spin mononuclear cobalt (II) (S = 3/2) in 6. The magnitudes of axial (D) and rhombic (E) zero-field splitting (ZFS) for the mononuclear Co(II) in 6 were determined approximately as 29.35 cm-1 and 6.46 cm-1.

Este estudo de caso pedagógico, sobre a função “Compras” da Portugal Telecom (PT), disponibiliza informação sintetizada e propõe uma abordagem para análise da mesma no meio académico, ou de formação profissional, como ferramenta de ensino e aprendizagem. A importância desta função para uma organização é a razão para a preparação deste estudo de caso. É objetivo geral deste estudo de caso contribuir para que os alunos e formandos adquiram conhecimentos sobre todas as componentes envolvidas no desempenho desta função e sobre a sua relevância e contribuição para a sustentabilidade empresarial. O estudo da aplicação de práticas de sustentabilidade na função “Compras” das organizações está pouco explorado na literatura. Mais investigação acerca da ligação entre "Sustentabilidade" e a função “Compras” permite um melhor entendimento do seu efetivo potencial, com levantamento de vantagens e desvantagens. Neste contexto, também foi objetivo deste estudo de caso pedagógico apresentar o Modelo de Compras da PT como um exemplo bem sucedido desta ligação, evidenciando precisamente a ambivalência deste modelo: por um lado, as suas características de robustez, transparência, e eficiência e, por outro, o uso de critérios de sustentabilidade (como uma prioridade). Por fim, este estudo procura salientar a relevância crescente dos dois componentes desta ligação: da sustentabilidade pela urgente necessidade de garantir que o consumo de recursos naturais hoje não compromete as gerações futuras; e da função “Compras” pela recente alteração do seu estatuto dentro de uma organização.<br>This pedagogical case study, about the Portugal Telecom (PT) Function of "procurement", Provides systematic information and proposes an approach to analyze it, in academic or professional training, as a tool for teaching and learning. The importance of the "Procurement" function for a specific organization it's the reason why this case study was prepared. The main objective is to contribute to the learning process of students and trainees about all the components relevant for this function, including its contribution to corporate social responsibility and sustainability. The study of the implementation of sustainability practices in the "Procurement" function is scarcely studied. More research of the link between "Sustainability" and "Procurement" allows a better understanding of its effective potential, identifying its advantages and disadvantages. In this context , it is also intent of this study to present in this pedagogical case study the “Procurement Model” of PT as a successful example of this link, demonstrating firstly, the characteristics of robustness , transparency and efficiency of the procurement process, and secondly, the use of sustainability criteria (understood as a priority). Finally, this study tries to emphasize the growing importance of the two components of this link: sustainability as an urgent need to ensure that the consumption of natural resources today does not compromise the future generations; and the recent change in “Procurement” status within an organization.