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1.Direct Determination of Noble Metals in Road Dust Samples by ETV-ICP-MS with Slurry Sampling 2.Determination of Trace Element in Oil Samples by ETV-ICP-MS Using Palladium Nanoparticles as Chemical ModifierHsu, Wan-Hsuan 23 July 2012 (has links)
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Applications of hydrogenation and dehydrogenation on noble metal catalystsWang, Bo 15 May 2009 (has links)
Hydrogenation and dehydrogenation on Pd- and Pt- catalysts are encountered in
many industrial hydrocarbon processes. The present work considers the development of
catalysts and their kinetic modeling along a general and rigorous approach. The first part
deals with the kinetics of selective hydrogenation, more particularly of the C3 cut of a
thermal cracking unit for olefins production. The kinetics of the gas phase selective
hydrogenation of methyl-acetylene (MA) and propadiene (PD) over a Pd/γ-alumina
catalyst were investigated in a fixed bed tubular reactor at temperatures 60 - 80 oC and a
pressure of 20 bara. Hougen-Watson type kinetic equations were derived. The formation
of higher oligomers slowly deactivated the catalyst. The effect of the deactivating agent
on the rates of the main reactions as well as on the deactivating agent formation itself
was expressed in terms of a deactivation function multiplying the corresponding rates at
zero deactivation. Then, the kinetic model was plugged into the reactor model to simulate an industrial adiabatic reactor. In the second part the production of hydrogen
from hydrocarbons was investigated. In both cyclohexane and decalin dehydrogenations,
conversions higher than 98% could be obtained over Pt/γ-alumina catalyst at temperature
of 320 and 340 oC, respectively, with no apparent deactivation for 30 h and with co-feed
of H2 in the feed. Except for H2 and trace amounts of side cracking products, less than
0.01%, benzene was the only dehydrogenated product in cyclohexane dehydrogenation.
In the case of decalin dehydrogenation, partially dehydrogenated product, tetralin, was
also formed with selectivity lower than 5%, depending on operating conditions. A
rigorous Hougen-Watson type kinetic model was derived, which accounted for both the
dehydrogenation of cis- and trans- decalin in the feed and also the isomerization of the
two isomers. Jet A is the logic fuel in the battlefields. The dehydrogenation of Jet A can
produce H2 for military fuel cell application. Although the H2 production is lower than
that of steam/autothermal reforming, it eliminates the needs of high temperature and
product separation operation.
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Microplasma Discharges in High Pressure Gases Scaling Towards the Sub-micron RegimeChitre, Aditya Rajeev 2010 December 1900 (has links)
Atmospheric pressure microplasmas are uniquely characterized by their very high energy densities and also by their small discharge sizes. These properties allow for unique applications in plasma processing technologies. We have investigated the operational characteristics of microplasmas at higher energy densities and smaller sizes by operating microplasma configurations at high pressure conditions.
We studied the discharge and analyzed its variation with changes in current and pressure. The discharge was analyzed by microscopic visualization and data from the images and was processed to measure the current density and estimate charged particle density. By increasing the pressure beyond 200 psi and by minimizing the discharge current required for sustaining the plasma, we have been able to achieve discharge sizes of 7 mu m in nitrogen and as small as 20 μm in helium. Optical emission spectroscopic studies were carried out to measure gas temperature and vibrational temperature using the nitrogen 2nd positive system. With increase in pressure, the transition from non-equilibrium plasma to equilibrium plasma was also studied using the OES temperature measurements. iv
Temperature measurements are also used to estimate normalized current densities. Normalized current density results obtained after introducing the corrected effective pressure based on the increased gas temperature are close to the value of 400 mu A /cm^2*Torr^2 obtained for low pressure normal glow discharges in nitrogen.
This research presents further validation of the general operational characteristics of microplasmas being pressure scaled versions of normal glow discharges. Attained energy densities are ten to twenty times higher than in atmospheric pressure microplasmas. Discharge sizes are also significantly smaller, decreasing with increasing pressure, but the scaling is with density ‘nd’ rather than pressure ‘Pd’ due to the increase in gas temperature with pressure, indicating a dependence on collisional processes. We can infer that at higher pressures, the operational characteristics of more complex plasma discharges like dielectric barrier discharges, RF plasmas, etc. follow scaling patterns, transitions and limits similar to the microplasma discharge studied in this thesis.
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The Study of Organic Solar Cell Doped with Metallic NanoparticleTsai, Ying-Chen 21 July 2008 (has links)
Polymers are with low carrier mobility. If polymer solar cells are to exhibit high power conversion efficiencies, their carrier mobilities must be improved. Metallic NPs are promising materials for use in polymer solar cells because of their high conductivities.
In this work, we studied the carrier transport characteristic of metallic nanoparticle blending into polymers. We blended Pt nanoparticles (Pt NPs) and Pd nanoparticles (Pd NPs) into polymers to improve carrier mobility, and enhance the power conversion efficiency of the polymer solar cell. P3HT was used as a donor material because of its high stability and with high absorption in visible light. PCBM was used as a acceptor material because of its high stability and with high electron transportation.
We blended modified Pt NPs and Pd NPs into the P3HT:PCBM active layer, with the device configurations of ITO/PEDOT:PSS/P3HT:PCBM:
Pt NPs/Al and ITO/PEDOT:PSS/P3HT:PCBM:Pd NPs/Al, respectively polymer solar cells measured was under AM 1.5G 100mW/cm2 illumination. When we blended Pt NPs into the active layer, the open-circuit remained 0.64V, the short-circuit current increased from 6.67mA/cm2 to 9mA/cm2, the power conversion efficiency increased from 1.96% to 3.08%. When we blended Pd NPs into the active layer, the open-circuit remained 0.62V, the short-circuit current increased from 6.33mA/cm2 to 7.33mA/cm2, the power conversion efficiency increased from 1.7% to 2.48%.
The enhanced efficiency originated from the increased carrier mobility of the active layer when the Pt NPs or Pd NPs were present.
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Al-Au-Cu and Al-Au-Pd phase diagram study using diffusion couplesLi, Jyun-lin 21 July 2008 (has links)
none
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CONTROL OF BUCK CONVERTER BY POLYNOMIAL, PID AND PD CONTROLLERS. / KONTROLL AV BUCK omvandlaren med polynom, PID och PD Controller.SEKHAR, MADHU KIRAN . EDURU RAJA CHANDRA, THOTA, PARTHA SARADHI . January 2012 (has links)
This thesis is an ongoing project of Ericsson with collaboration of Blekinge Institute of Technology [BTH], and Linneaus University [LNU] to compare the functionality and performance of three controllers Polynomial Pole Placement, PID [Proportional Integral Derivative] and PD controller in third order. This paper presents the state space modeling approach of DC-DC Buck converter. The main aim of this thesis is, by considering the buck converter system of Ericsson BMR450 with the PID, POLYNOMIAL and PD controllers at feedback loop, thus running their Matlab file with their appropiate Simulink block diagram, and comparing the three controllers performance by verifying their appropiate output graphs. The third order controller design is complicated and response is slow. The second order design is easy and gives better responses than third order Polynomial, PID and PD controllers. / As per the results point of view, the polynomial performed well than PID and PD controllers. The simulations show that the polynomial controller reaches the reference voltage very well, were the PID and PD result does not differ very much while meeting with the required reference voltage. Thus we conclude that the Polynomial controller design and results were better than the PID and PD Controllers. If we compare both the second order [4] and third order controller methods, The second order controllers are easy in design and gives better responses than third order polynomial PID and PD controllers. / ERCS.MADHU KIRAN, D.NO: 1/1/131, B.C.COLONY, MUTHUKUR, NELLORE, ANDHRA PRADESH, INDIA. PIN - 524344. THOTA. Partha Saradhi, C/O CH SUVARNA RAJU D.NO: 4-5-47, VEGIVARI CHAVADI, KOTHA PETA, WARD NO:21, KOVVUR, WEST GODAVARI,ANDHRA PRADESH, INDIA PIN - 534350,
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Experimental development of a chemical flood and the geochemistry of novel alkalisWinters, Matthew Howard 06 November 2012 (has links)
Surfactant-Polymer (SP) and Alkaline-Surfactant-Polymer (ASP) floods are tertiary oil recovery processes that mobilize residual oil to waterflood. These Chemical EOR processes are most valuable when the residual oil saturation of a target reservoir to waterflood is high. The first steps of designing a SP or ASP flood are performed in a laboratory by developing a surfactant formulation and by performing core flood experiments to assess the performance of the flood to recovery residual oil to waterflood. The two criteria for a technically successful laboratory SP or ASP core flood are recovering greater than 90% of residual oil to waterflood leaving behind less than 5% of residual oil and accomplishing this at a field scalable pressure gradient across the porous medium of approximately 1 psi per foot. This thesis documents the laboratory development of SP and ASP core floods for a continental Unites States oil reservoir reported to contain the minerals anhydrite and gypsum. The significance of these minerals is that they provide an infinite acting source of calcium within the reservoir that makes using the traditional alkali sodium carbonate unfeasible using conventional Chemical EOR methods. This is because sodium carbonate will precipitate as calcite in the presence of free calcium ions. Secondly, this thesis investigates two novel alkalis that are compatible with free calcium ions, sodium acetate and tetrasodium EDTA, for their viability for use in ASP floods for reservoirs containing anhydrite or gypsum. / text
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Considering security in Florida's transportation project development processStevens, Phillip W 01 June 2006 (has links)
The transportation decision-making process takes on different forms in different states. The purpose of this study was to include and move considerations for national, state, and local security needs into the transportation project development arenas with a focus on Florida. A thorough and updated literature review was completed to determine the current state of the industry regarding incorporating security considerations into the transportation planning process. A review of current Federal, State, and Local laws and regulations concerning planning requirements was conducted to outline planning parameters and limitations. An information request letter was mailed to the key planning staff members for all 50 states in the United States, the District of Columbia and Puerto Rico and other key stakeholders. An online survey was conducted to determine public opinion about transportation security. As a result of these efforts, a modified PD&E process was developed, key findings were identified, future research needs were defined, and an outline of next steps was developed.
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Desarrollo de un modelo experimental para el estudio in vivo de la farmacodinamia de los antimicrobianosMeneses, María Laura 14 April 2015 (has links)
En la actualidad, la CIM asume un papel fundamental en el cálculo de los parámetros farmacocinéticos/farmacodinámicos, T>CIM; AUC/CIM y Cmax/CIM, considerados como predictores de la eficacia antimicrobiana. Sin embargo, la importancia de la CIM como parámetro de la eficacia in vivo de un antimicrobiano es controversial. Las condiciones estandarizadas de la prueba (tamaño de inóculo definido, medios artificiales y concentraciones estáticas) son realmente diferentes de las esperadas en el sitio de infección. Dichas controversias han obligado a los investigadores ha diseñar modelos experimentales in vivo. Sin embargo los modelos diseñados hasta el momento no poseen enfoques adecuados para una correcta evaluación de lo que ocurre durante el tratamiento antimicrobiano de un proceso infeccioso, limitándose a conclusiones de eventos particulares y estáticos. Basado en lo expuesto, en la actualidad se carece de un modelo in vivo aceptable que permita estudiar de forma integrada la farmacocinética y farmacodinamia de los antimicrobianos, que produzca información de calidad científica y al mismo tiempo respete el bienestar de los animales experimentales. En la presente tesis se propuso el desarrollo y la validación de un modelo de estudio in vivo completamente novedoso, que podría subsanar las debilidades encontradas en los modelos anteriores. Para cumplir este objetivo, se diseñó un dispositivo de implantación subcutánea (DIS) que permitió el estudio in vivo del crecimiento bacteriano y su modificación por la aplicación de diferentes estrategias terapéuticas. El modelo permitió la integración PK/PD y la identificación de correlaciones entre los diferentes parámetros farmacocinéticos y las curvas de muerte bacteriana. En resumen, el modelo experimental presentado en el presente trabajo de tesis resultaría adaptable para el estudio de la mayoría de los componentes del proceso infeccioso, como ser formación de biofilm, persistencia bacteriana, efecto inóculo, etc. A su vez es un modelo que ofrece la posibilidad de trabajar con animales sanos sin producir septicemia y respetando el bienestar de los mismos. / Nowadays, MIC is considered fundamental for parmacokinetic/ pharmacodynamic parameter calculation, T>CIM; AUC/CIM y Cmax/CIM, consider as efficacy predictors. However, the importance of MIC as an in vitro efficacy parameter for antimicrobials is controversial. Standardized conditions on MIC test (inoculums size, artificial culture mediums and static concentrations) are really different to that expected at the site of infection. Mentioned controversies have forced researches to develop in vivo experimental models. However, models designed so far lack of appropriate focus for a proper evaluation of the scenario during an antimicrobial treatment of an infectious process; conclusions, then, are limited to particular and static events.
Based on the previously presented information, there is not an acceptable in vivo model allowing the integrated study of antimicrobials pharmacokinetics and pharmacodynamics, which would produce high quality scientific information, and at the same time, sustain animal welfare.
In the present Thesis, for covering the weaknesses of older models, the development and validation of a novel and original in vivo model was proposed. For achieving this goal, a device for subcutaneous implantation was designed and validated. This device allowed the in vivo study of bacterial growing together with its modification by different therapeutic interventions.
The model allowed PK/PD integration and identification of correlation between PK parameters and bacterial death curves. In summary, the experimental model presented in this thesis is flexible and can be adapted for studying most of the components of the infectious process, such as, biofilm formation, bacterial persistence, inoculum-effect, etc. Also, the model allows to work with healthy experimental animals, avoiding septicaemia induction and then, sustaining welfare.
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Preparation, Characterization and Testing for Photocatalytic Activities of Bi2WO6-based MaterialsQin, Hanna 13 December 2012 (has links)
PdCl2/Bi2WO6 and Pd/Bi2WO6 composite photocatalysts were synthesized via a template free hydrothermal process and the respective photocatalytic activities were investigated by degradation of Rhodamine B. The new catalyst composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet visible (UV-vis) light diffuse reflectance spectra, respectively. By XRD, it was found that the loaded Pd species did not alter the crystal lattice of Bi2WO6 photocatalyst. Through the XPS spectra, it was found that the PdCl2/Bi2WO6 was successfully reduced by chemical reducing agents CH2O and N2H4, respectively, and palladium was present in the form of both metallic Pd and Pd ion spe-cies (Pd0 and Pd2+), while the Pd species in a NaBH4-reduced composite exhibited only metallic Pd species (Pd0). For the SEM images, it was observed that both classes of composites were constructed from plenty of nanoplates, which were closed packed with hierarchical structures. Furthermore, the removal efficiency of Rhodamine B was found to be influenced by parameters such as catalyst dosage, pollutant concentration and solution pH.
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