Development Of Wide Band Gap Semiconductor Materials For Renewable Energy,
2010
University of Texas at El Paso
Development Of Wide Band Gap Semiconductor Materials For Renewable Energy, S.M. Sarif Masud
Open Access Theses & Dissertations
Several new wide band gap semiconductor nanocomposite photocatalytic materials have been synthesized from HTiNbO5 and HNb3O8 for solar energy conversion. As a source of renewable energy, the materials are being tested to produce hydrogen fuel from water via photolysis. The materials have high surface areas, are macroporous, and have flatband potentials suitable for reducing water to create hydrogen. Under visible or ultra violet light, the materials were found to be very promising as hydrogen evolving photocatalysts. As part of the synthesis of the composites, the catalysts also exhibited excellent catalytic activity under UV light for reducing ionic platinum and gold …
Use Of A Segmented Electrode To Control Current Distribution In Electrochemical Systems,
2010
CUNY City College
Use Of A Segmented Electrode To Control Current Distribution In Electrochemical Systems, Barry Van Tassell
Dissertations and Theses
"The goal of this project was to investigate the use of segmented electrodes to control the current distribution through an electrochemical cell. To achieve this goal, the project was separated into two parts, designing a scalable piece of hardware that could create a current distribution, and then using that hardware to create noticeable changes in a system by changing the current distribution within the system. Prior to building the current distribution device, a basic 3-electrode galvanostat was built in order to test its fundamental design characteristics. The design stressed a simplistic hardware, relying on software to control the current. A …
Microalgae Harvesting By Flocculation With Polymer-Coated Magnetite Particles,
2010
Missouri University of Science and Technology
Microalgae Harvesting By Flocculation With Polymer-Coated Magnetite Particles, Humayun Shariff
Masters Theses
"Although microalgae are considered to be one of the potentially significant feedstock for renewable biofuels, harvesting them efficiently from culture ponds has been a major hurdle. The conventional harvesting methods such as centrifugation and filtration are very time and labor intensive processes. Gravimetrical settlement with the aid of cationic flocculants is the most widely employed technique, but suffers from the difficulty in recovering microalgae floes. Furthermore, recycling of these flocculants after the harvesting process is not possible. Polymer-coated magnetite particles have been investigated for applications in various fields. This research has focused on the development of a novel and efficient …
Electrodeposited Cu-Based Catalysts For Alcohols From Co Hydrogenation And Electrodeposition Of Cuniw/Cuni Multilayered Alloys,
2010
Louisiana State University and Agricultural and Mechanical College
Electrodeposited Cu-Based Catalysts For Alcohols From Co Hydrogenation And Electrodeposition Of Cuniw/Cuni Multilayered Alloys, Mayank Gupta
LSU Doctoral Dissertations
Ethanol and higher alcohols can be used as a fuel or fuel additive in gasoline engines as well as a hydrogen carrier. One of the promising methods to synthesize these alcohols is based on thermochemical conversion of CO and H2 (CO hydrogenation). Conventional catalysts used for the conversion CO and H2 (syngas) to ethanol typically give yields less than 20% with the balance resulting mostly in the formation of the thermodynamically favored products CH4 and CO2. New catalysts with compositions designed to kinetically favor the formation of ethanol and higher alcohols are needed. Electrodeposition of nanowires offers a means to …
X-Ray Absorption Spectroscopy Applied To Mixed-Metal Iron-Based Fischer-Tropsch Catalysts,
2010
Louisiana State University and Agricultural and Mechanical College
X-Ray Absorption Spectroscopy Applied To Mixed-Metal Iron-Based Fischer-Tropsch Catalysts, Andrew Allen Campos
LSU Doctoral Dissertations
Synthetic fuels derived from methane, coal or biomass are essential in addressing future transportation fuel demands which are expected to exceed petroleum-derived capacities. The Fischer-Tropsch synthesis (FTS) is the most studied technique for the conversion of coal or biomass-derived syngas into transportation fuels. Fe-based catalysts are typically used for the FTS of biomass and/or coal-derived syngas due to: the relatively low cost of iron, water-gas shift activity, and low methane selectivity at industrial FTS conditions. Fe/Cu/SiO2 Fischer-Tropsch catalysts promoted with Cr, Mn, Mo, W, or Zr were studied in-situ, using Fe K-edge TPR XANES (temperature programmed reduction X-ray absorption near-edge …
Modeling And Multiresolution Characterization Of Micro/Nano Surface For Novel Tailored Nanostructures,
2010
Louisiana State University and Agricultural and Mechanical College
Modeling And Multiresolution Characterization Of Micro/Nano Surface For Novel Tailored Nanostructures, Rajib Mukherjee
LSU Doctoral Dissertations
Nanofabrication is state of the art technology. Various chemical, mechanical, biochemical and semiconductor products have characteristics controlled by the nanostructures of the surface and interphase. Surface microscopic imaging is generally used to capture different surface features. By properly analyzing the surface image, valuable information regarding manufacturing process and product performance can be extracted. While microscopy measurements can offer very accurate qualitative information about surface features, for many applications, it is critical to obtain a quantitative description of the surface morphology. Various statistical features can be used to characterize the surface in quantitative way. Such an analysis can be done by …
Supercritical Pyrolysis Of N-Decane,
2010
Louisiana State University and Agricultural and Mechanical College
Supercritical Pyrolysis Of N-Decane, Sean Bagley
LSU Doctoral Dissertations
Fuels used in future generations of high-speed jet aircraft will be required to take on increasing heat loads in their role as the primary coolant for the absorption of waste heat from the engine. As a consequence, the hydrocarbon fuels will be exposed to elevated temperatures and pressures prior to their use as fuels, conditions which are beyond the critical point of the fuel and which lead to the formation of carbonaceous solid deposits in the pre-combustion environment.
Deposition of solids causes reduced engine performance and eventual failure, so understanding the mechanisms by which thermally stressed hydrocarbons become solids is …
Response Surface Optimization Of Crystal Violet Decolorization By Pellets Of Pyncnoporus Sanguineus.,
2010
Universiti Malaya
Response Surface Optimization Of Crystal Violet Decolorization By Pellets Of Pyncnoporus Sanguineus., Siti Suhana Sulaiman
Student Works (2010-2019)
Ligninolytic enzymes of white-rot fungi have broad specificities and have been implicated in transformation and mineralization of organo-pollutant with chemical structure similar to lignin e.g. synthetic dyes. This study was carried out to optimize selected parameters for decolorization of Crystal violet by Pycnoporus sanguineus in shake flasks. The parameters studied were initial dye concentration (ppm), agitation speed (rpm) and process time. They were optimized using response surface methodology (RSM). Subsequent to the optimization, the decolorization process was scaled up in stirred tank reactor (STR). Effect of different geometry of impellers on the decolorization process was studied. Curved blade and angled …
Characteristics Of Proton Conducting Pva-Chitosan Polymer Blend Electrolytes.,
2010
Universiti Malaya
Characteristics Of Proton Conducting Pva-Chitosan Polymer Blend Electrolytes., Mohd Fakhrul Zamani Abdul Kadir
Student Works (2010-2019)
The main focus of this present work is to build a good conducting solid polymer electrolyte (SPE) based on chitosan and poly(vinyl alcohol)(PVA) blend. Solution cast technique has been employed to produce sample films in this work. From the scanning electron micrographs (SEM) the surface morphology of the blend containing 40 wt.% chitosan and 60 wt.% PVA (C4P6) is homogenous and miscible in one and another. The C4P6 film is the most amorphous and is the best candidate for the polymer host in the electrolyte systems studied in the present work. Ammonium Nitrate (NH4NO3) is the doping salt that provides …
Electrodeposition Of Tin Using Tin (Ii) Methanesulfonate From Mixture Of Ionic Liquid And Methane Sulfonic Acid.,
2010
Universiti Malaya
Electrodeposition Of Tin Using Tin (Ii) Methanesulfonate From Mixture Of Ionic Liquid And Methane Sulfonic Acid., Yang Kok Kee
Student Works (2010-2019)
The electrodeposition of tin from Tin(II) Methane Sulfonate (MSA) with varying concentration in air and water stable 1-butyl-1-methyl-pyrrolidinium trifluoromethanesulfonate, (BMPOTF) ionic liquid at room temperature was studied. Cyclic Voltammetry served to characterize the electrochemical behavior of tin reduction and oxidation. The diffusion coefficient of stannous ions in the mixture of BMPOTF ionic liquid and MSA based electrolyte obtained via Randles-Sevcik and Cottrell equation was 2 × 10-7 cm2/s. Electroplating on copper panel was conducted under different current densities to determine BMPOTF based tin plating solution current efficiency. Mixture of BMPOTF and MSA based tin plating solution gave current efficiency as …
Synthesis Of Urethane Acrylate Macromer From Palm Oil-Based Polyol And Its Application As A Resin For Dental Composite.,
2010
Universiti Malaya
Synthesis Of Urethane Acrylate Macromer From Palm Oil-Based Polyol And Its Application As A Resin For Dental Composite., Fadhel A. A. Alsanabani
Student Works (2010-2019)
A slightly branched urethane acrylate macromer (UAM) was synthesized by reacting palm oil-based polyol with excess amounts of polymeric methylene diphenyl diisocyanate (MDI) to form urethane prepolymer, then reacted with 2-hydroxyethyl methacrylate (HEMA) and FT-IR spectroscopy confirmed the urethane and grafted acrylate groups. 0.2% by weight of camphoroquinone (CQ) and 0.8% by weight of ethyl-4-N,N-dimethylamino-benzoate (4EDMAB) by weight were added to render the experimental resins light-curable. Their viscosity, percentage of degree of conversion (%DC) and cross-linking density (CLD), percentage of volumetric polymerization shrinkage (%VPS), water sorption and solubility, flexural strength, modulus of elasticity and toughness were determined and compared to …
Thermo-Electrical And Mechanical Studies On Polymer-Organically Modified Montmorillonite Composite.,
2010
Universiti Malaya
Thermo-Electrical And Mechanical Studies On Polymer-Organically Modified Montmorillonite Composite., Norhana Abdul Halim
Student Works (2010-2019)
The field of polymer-nanoclay composite has attracted a lot of attention in materials studies due to the dramatic improvement on polymers characteristics. For example mechanical and thermal properties, chemical resistance as well as the reduced gas permeability. However, structural changes and the mechanisms that may contribute to these improvements are not fully understood. In this work, the study on polymer nanoclay composite concentrates on the effects of OMON inclusion within different polymer matrix systems. The matrixes are a series of natural rubbers (Standard Malaysia Rubber – Latex grade (SMRL); Deproteinized Natural Rubber (DPNR) and Epoxidized Natural Rubber (ENR-50)), plasticized Polyvinyl …
Electrical And Structural Studies Of Polyacrylonitrile (Pan) Complexed With Inorganic Salts.,
2010
Universiti Malaya
Electrical And Structural Studies Of Polyacrylonitrile (Pan) Complexed With Inorganic Salts., Khairul Bahiyah Md Isa
Student Works (2010-2019)
In the present study, polymer electrolyte films composed of polyacrylonitrile (PAN) as a host polymer, ethylene carbonate (EC) as the plasticizer and lithium triflate (LiCF3SO3) and sodium triflate (NaCF3SO3) as dopant salts were prepared by the solution cast technique. Five systems of polymer electrolytes films have been prepared; these systems are the plasticized-PAN system i.e. PAN-EC system, two salted-PAN systems i.e. PAN-LiCF3SO3 and PAN-NaCF3SO3, and two plasticized-salted PAN systems i.e. PAN-EC-LiCF3SO3 and PAN-EC-NaCF3SO3. The pure PAN film was prepared as a reference. The ionic conductivity for each system is characterized using impedance spectroscopy. The room temperature conductivity of the pure …
Synthesis Of Chromium-Based Ziegler-Natta Catalysts And Thier Application In Ethylene Polymerization And Copolymerization.,
2010
Universiti Malaya
Synthesis Of Chromium-Based Ziegler-Natta Catalysts And Thier Application In Ethylene Polymerization And Copolymerization., Wong Jun Xuan
Student Works (2010-2019)
Four chromium-based oxo-trinuclear carboxylate complexes were prepared by reacting Cr(NO3).9H2O with acetic acid and substituted carboxylic acids to produce [Cr3O(CH3COO)6.3H2O]NO3.7H2O,[Cr3O(ClCH2COO)6.3H2O]NO3.3H2O, [Cr3O(Cl2CHCOO)6.3H2O]NO3.H2O and [Cr3O(Cl3CCOO)6.3H2O]NO3.2H2O, which alysis (TGA).Chromium content in each complex was determined by titrimetry method and the result was in good agreement with that from TGA. Chromium(III)monochloroacetate complex[Cr3O(ClCH2COO)6.3H2O]NO3.3H2O in combination with diethylaluminium chloride formed heterogeneous catalyst system for ethylene polymerization and ethylene-propylene copolymerization. Both Al/Cr ratio and temperature influenced the catalytic activity. The maximum activity of ethylene polymerization was 1768 gPE/gCr/hr/atm, achieved by polymerizing ethylene at 29°C with Al/Cr ratio 30.8. Effect of chloro-substituent groups on carboxylic ligand was studied …
Electrodeposition Of Tin Using Tin(Ii) Methanesulfonate From Mixture Of Ionic Liquid And Methane Sulfonic Acid.,
2010
Universiti Malaya
Electrodeposition Of Tin Using Tin(Ii) Methanesulfonate From Mixture Of Ionic Liquid And Methane Sulfonic Acid., Yang Kok Kee
Student Works (2010-2019)
The electrodeposition of tin from Tin(II) Methane Sulfonate (MSA) with varying concentration in air and water stable 1-butyl-1-methyl-pyrrolidinium trifluoromethanesulfonate, (BMPOTF) ionic liquid at room temperature was studied. Cyclic Voltammetry served to characterize the electrochemical behavior of tin reduction and oxidation. The diffusion coefficient of stannous ions in the mixture of BMPOTF ionic liquid and MSA based electrolyte obtained via Randles-Sevcik and Cottrell equation was 2 × 10-7 cm2/s. Electroplating on copper panel was conducted under different current densities to determine BMPOTF based tin plating solution current efficiency. Mixture of BMPOTF and MSA based tin plating solution gave current efficiency as …
Effect Of Selected Physical And Chemical Parameters On Crystal Violet Decolorization By Immobilized Laccase.,
2010
Universiti Malaya
Effect Of Selected Physical And Chemical Parameters On Crystal Violet Decolorization By Immobilized Laccase., Nur Atiqah Ismail
Student Works (2010-2019)
Synthetic dyes are used for coloration of various materials like textiles, leather and food. Wastewater from dyeing industries constitutes a threat to the environment as many synthetic dyes are often toxic, mutagenic and carcinogenic. Besides, light absorption is hindered by the dyes run-off creating problems to photosynthetic aquatic plants and algae. Biodegradation of waste dyestuff with enzymes provides a viable alternative compared to the often expensive physical/chemical methods. Laccase from Trametes versicolor was chosen in this study as it exhibits low substrate specificity and high ability to oxidize many pollutants which suggested its potential in wastewater treatment and bioremediation. The …
Optimization Of Parameters And Study Of Kinetics In Lactulose Production By Lactose Isomerization Using Strong Basic Anion Exchange Resin,
2010
Missouri University of Science and Technology
Optimization Of Parameters And Study Of Kinetics In Lactulose Production By Lactose Isomerization Using Strong Basic Anion Exchange Resin, Arvind Nanduri
Masters Theses
"In this work, an experimental design was employed to investigate the effects of different operating conditions on the isomerization of lactose to lactulose by using strong basic anion exchange resin (AMBERLITE-IRA 402). Temperature, resin/lactose mass ratio and pH were considered to be the three factors affecting the conversion of lactose. Box-Behnken design was then used to optimize the operating conditions for maximum response and also to study the various interaction and main effects of the factors. The analysis of variance (ANOVA) of the experimental data showed a high correlation coefficient R² (0.99) and a low root mean square error (2.84) …
Fabrication Of A Memory Device Using Polyaniline Nanofibers And Gold Nanoparticles,
2010
Missouri University of Science and Technology
Fabrication Of A Memory Device Using Polyaniline Nanofibers And Gold Nanoparticles, Krunal R. Waghela
Masters Theses
"Fabrication of a memory device using one-step/one-pot synthesis for making a PANI (polyaniline)/Au nanocomposite is reported. Although various devices with horizontal and vertical electrode structures were made, the basic structure used consisted of a PANI/Au thin film sandwiched between two electrodes. The ratio of the current in the OFF state to the current in the ON state was seen to be as high as 5000. These devices showed a bistable behavior, which is typical of memory devices. The PANI/Au nanocomposite thin film was constructed right on the electrode using microfabrication techniques with ultraviolet irradiation. The fabrication techniques discussed in this …
Enhanced Photorefractivity In A Polymeric Composite Photosensitized With Modified Carbon Nanotubes,
2010
Missouri University of Science and Technology
Enhanced Photorefractivity In A Polymeric Composite Photosensitized With Modified Carbon Nanotubes, Naveen Kumar Lingam
Masters Theses
"This work involves the photosensitization of photorefractive polymeric composites through the inclusion of multiwalled and singlewalled carbon nanotubes grafted to poly(N-vinyl carbazole). The photorefractive nature of the holograms gratings was established using two-beam-coupling, yielding two-beam-coupling gain coefficients approaching 80 cm⁻¹. Degenerate-four-wave-mixing experiments exhibited diffraction efficiencies as high as 60% as well as over-modulation voltages as low as ~ 40 V/µm. These notable figures of merit indicate that the grafting of the various carbon nanotubes to the poly(N-vinyl carbazole) polymer resulted in enhanced photorefractive performance. The mechanism responsible for this enhancement in photorefractive performance is investigated using a variety of experimental …
Biodiesel Production Using Supercritical Methanol,
2010
Missouri University of Science and Technology
Biodiesel Production Using Supercritical Methanol, Dhaval Nitin Modi
Masters Theses
"The catalyst-free transesterification of oil (triglycerides) in supercritical methanol at a temperature and pressure above 239⁰C and 8.1MPa, respectively, provides a new way of producing biodiesel. High reaction temperature and pressure help to accelerate the transesterification because the supercritical methanol becomes non-polar and has enhanced contact with oil. The supercritical transesterification of soybean oil was carried out in a 170 ml volume high-pressure batch reactor. The pressure within the batch reactor was self-generated from heating the contents since no pumps were used. Transesterification of soybean oil with supercritical methanol readily produced biodiesel. Since the supercritical transesterification is carried out without …
