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Articles 5791 - 5820 of 14175

Full-Text Articles in Engineering

Technique For The Synthesis Of Difluorinated Organic Molecules Using Magnesium Bases, Cassidy S. Baldwin Jan 2018

Technique For The Synthesis Of Difluorinated Organic Molecules Using Magnesium Bases, Cassidy S. Baldwin

Honors Theses

The presence of fluorine in organic molecules can confer biological advantages which are often exploited in drug development. For example, fluorine has been shown to limit drug metabolism and enhance drug distribution. However, the development of fluorinated pharmaceutics poses synthetic challenges. These challenges are especially pronounced when developing molecules with a difluoromethyl group. One difluoromethyl functional group of particular interest is the α,α-difluoro-β-amino carbonyl group, which has been seen in potential drug leads. The previous methods of accessing this group are inefficient and complex. The goal of this project was to develop a new technique to access this group by …

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Inhibition Of Blood Coagulation Factor Xii: Evaluation Of Flavonoids As A Drug Candidate, Betsy Crosswhite Jan 2018

Inhibition Of Blood Coagulation Factor Xii: Evaluation Of Flavonoids As A Drug Candidate, Betsy Crosswhite

Honors Theses

This study investigated natural product inhibitors of blood coagulation Factor XII (FXII). FXII initiates the Kallikrein Kinin-System (KKS) within the intrinsic coagulation pathway. Increased expression of this system leads to proinflammatory and procoagulant activities. Inflammation occurs through downstream activation in the KKS. Following the activation of FXII-dependent pathway, bradykinin (BK) binds to the BK receptor 2 (B2) and produces inflammatory signaling. Abnormally increased BK can result in life threatening Hereditary Angioedema (HAE), characterized by severe reoccurring swelling. FXII is critical for pathogenic thrombosis, but is dispensable for hemostasis. This unique property of FXII makes it an attractive drug target. We …

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Perceptions Regarding Concussions In Collegiate Football At The University Of Mississippi, Madison Frerker Jan 2018

Perceptions Regarding Concussions In Collegiate Football At The University Of Mississippi, Madison Frerker

Honors Theses

Concussions are a form of mild traumatic brain injury (mTBI) that can occur from any force to the head or body that causes the brain to move within the skull. Concussions are common in the sport of football due to the highly physical nature of the sport, and injured athletes can experience a wide array of symptoms. Like other players participating with powerhouse football programs, those at the University of Mississippi are at risk of concussion throughout their collegiate career. Whether players and fans perceive the risks of concussion equally has not been previously studied. Considering the passionate history of …

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Development Of A Scn1a Null Zebrafish Model For Screening Potential Anti-Epileptic Natural Products, Patricia Ann Lipson Jan 2018

Development Of A Scn1a Null Zebrafish Model For Screening Potential Anti-Epileptic Natural Products, Patricia Ann Lipson

Honors Theses

Epilepsy affects around 50 million people in the world. Thus, it is imperative that new more effective and safe treatments be found. This study was designed to use zebrafish to screen potential anti-epileptic natural products. We utilized two scn1Lab null zebrafish models (morpholino-injected fish where scn1Lab was transiently knocked down and a transgenic scn1Lab -/- fish line). Alternatively, we used AB wildtype fish to test compounds in a chemically-induced seizure model. Natural compounds including cannabidiol, CBD, and Tapinanthus globiferous, TG, extracts were screened for their anti-seizure activity. When scn1Lab -/- fish were treated with CBD (0.075 and 0.3 mg/L) from …

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A Case Study On The Design And Optimization Of An Ethylbenzene Production Plant, William Grafton Peaster Jan 2018

A Case Study On The Design And Optimization Of An Ethylbenzene Production Plant, William Grafton Peaster

Honors Theses

This thesis will detail two goals of my capstone design project. The first goal is to simulate a given base case of a vapor phase reaction ethylbenzene production facility in PRO/II simulation software and discretely optimize the process in order to increase the profitability of the plant. The second goal is to develop a base case process flow diagram, stream tables, utility tables, and equipment tables for an ethylbenzene facility with liquid phase reactions. The base case simulation and optimization is a group task with my assigned group members in Ch E 451. The first part of this study looks …

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Process Design And Optimization: Analysis Of An Ethylbenzene Production Plant, Jonathan Butler Vanveckhoven Jan 2018

Process Design And Optimization: Analysis Of An Ethylbenzene Production Plant, Jonathan Butler Vanveckhoven

Honors Theses

This thesis will cover the steps I took to evaluate an ethylbenzene production plant. I, along with my senior design team, was first tasked with optimizing a vapor-phase ethylbenzene production plant based off of a given base case. Our team was able to improve the net present value of the plant from -$4.8 million to $70.4 million through discrete optimization. After the vapor-phase plant was evaluated, I was tasked with creating a base case, liquid-phase ethylbenzene production plant. I explain the theory behind process flow diagram development, then explain how I produced the process flow diagram and stream table for …

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Solvent And Concentration Effects Governing The Hierarchical Organization Of Asphaltenes: A Small-Angle X-Ray Scattering Study, Hasan Rejoanur Rahman Jan 2018

Solvent And Concentration Effects Governing The Hierarchical Organization Of Asphaltenes: A Small-Angle X-Ray Scattering Study, Hasan Rejoanur Rahman

Open Access Theses & Dissertations

Asphaltenes are a group of planar molecules found in crude oil and are prone to aggregation which often causes blockage of pipes along the oil production stream resulting a huge economic downside. In an effort to understand the hierarchical organization of asphaltene in different solvents and concentrations, the solution structure of various asphaltene solutions were studied using small-angle x-ray scattering (SAXS). Solvents were chosen based on miscibility maps. Such maps are generated on the critical value of the solubility parameter difference between asphaltenes or asphaltene components, and a range of solvents. The critical factors that affect asphaltene and asphaltene component …

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Stabilization Of Silicon And Germanium Based High Capacity Anodes For Lithium Ion Batteries, Kuber Mishra Jan 2018

Stabilization Of Silicon And Germanium Based High Capacity Anodes For Lithium Ion Batteries, Kuber Mishra

Theses and Dissertations

Lithium-ion batteries (LIBs) have been the driver of the widespread application of portable electronics. As the electronic devices have been more powerful and versatile, the pressing demand for higher energy density batteries have led the extensive explorations of novel materials for high capacity electrodes. Despite several breakthroughs in literature, the current state of art LIBs still uses the battery chemistry developed in early 1990s.The keys challenges for switching to other high capacity electrodes have been high cost, non-linear scalability and poorer electrochemical performance. This dissertation focusses on development of high capacity electrodes in order to increase the energy density of …

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Design, Synthesis, And Characterization Of Monometallic And Bimetallic Catalysts, Sonia Eskandari Jan 2018

Design, Synthesis, And Characterization Of Monometallic And Bimetallic Catalysts, Sonia Eskandari

Theses and Dissertations

Supported catalysts are used extensively in a variety of heterogeneously catalyzed reactions for industrial processes. Techniques for preparing supported noble metal catalysts are typically chosen to achieve high metal dispersions in order to obtain high activity for a given metal loading. Enhancing the catalytic performance of heterogeneous catalysts can be done by increasing active site count as well as modification of the physico-chemical characteristics of the catalyst material. For supported metal nanoparticles this can be achieved by decreasing particle size, thus increasing dispersion or metal utilization on the surface of the particles, while modification of metal properties can be attained …

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Simulation Of Water Effect On Biodiesel Production Using Waste Cooking Oil Via Ester-Transesterification In A Reactive Distillation Column, Ajala Anantapinitwatna Jan 2018

Simulation Of Water Effect On Biodiesel Production Using Waste Cooking Oil Via Ester-Transesterification In A Reactive Distillation Column, Ajala Anantapinitwatna

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research investigated the effect of water content in waste cooking oil (WCO) on the performance of a reactive distillation column for biodiesel production via ester-transesterification. A mixture of triolein and oleic acid was used as a WCO model compound. Amberlyst-15 was used to catalyze esterification while CaO was used for transesterification. From Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic model taking into account water absorption for esterification of oleic acid (FFA), biodiesel yield was decreased with increasing of water content in WCO feedstocks. On the other hand, the initial rate of transesterification was increased with increase of amount of water in WCO feedstocks …

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Synthesis Of Activated Carbons From Coffee Ground Residues And Their Application As Catalysts For Ethanol Dehydrogenation, Jeerati Ob-Eye Jan 2018

Synthesis Of Activated Carbons From Coffee Ground Residues And Their Application As Catalysts For Ethanol Dehydrogenation, Jeerati Ob-Eye

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this present study, characteristics and catalytic properties of activated carbon derived from coffee ground residue, cobalt metal (Co) supported-activated carbon and various metals (Ce, Co, Cu and Ni) supported-commercial activated carbon were determined and characterized. This study was divided into three parts. Regarding to the first part, the synthesis of activated carbon catalysts derived from coffee ground residues with different methods of physical activation was investigated. The results showed that the catalyst with physically activated by CO2 for 4 hours, exhibited the best catalytic activity of ethanol dehydrogenation to acetaldehyde. In the second part, the best catalyst from the …

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Simulation And Evaluation Of Butadiene Production From Ethanol Via One-Step Reaction, Jirawat Imsaard Jan 2018

Simulation And Evaluation Of Butadiene Production From Ethanol Via One-Step Reaction, Jirawat Imsaard

Chulalongkorn University Theses and Dissertations (Chula ETD)

1,3-butadiene is an important compound produced from the steam cracking process. Raising demand for alternatives to fossil fuels has led to an increase in bio-derived ethanol production, which can also be used as a feedstock for 1,3-butadiene synthesis. This research investigated the simulation of 1,3-butadiene production from ethanol using one-step process with 1.AI2O3/ZnO (60:40), 2.MgO-SiO2-Na2O (1:1)(0.1%) and 3.Hf2.5ZM1.6/SiO2 as heterogeneous catalysts. The process simulation was carried out using commercial Aspen plus 8.0 program and the heat utilization efficiency was evaluated by Aspen energy analyzer software. The process optimal condition sequences were identified by adjusting the separation distillation parameters which include …

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Effects Of Tio2 Support And Co Addition On Ni/Tio2 Catalysts In Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Kittithad Wonglekha Jan 2018

Effects Of Tio2 Support And Co Addition On Ni/Tio2 Catalysts In Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Kittithad Wonglekha

Chulalongkorn University Theses and Dissertations (Chula ETD)

Furfuryl alcohol is an important chemical intermediate that can be converted into many value-added derivative molecules. It is typically produced by the hydrogenation of furfural using supported metal catalysts. In this work, 15%wt Ni catalysts supported on titania (TiO2) were prepared by incipient wetness impregnation method. The effects of phase composition and average crystallite sizes of TiO2 and Co addition in the range of 1-3 wt% on the catalytic properties of 15 wt%Ni/TiO2 were investigated in the selective hydrogenation of furfural to furfuryl alcohol at 50°C, 20 bar of H2, and 2 h reaction time. It was found that Ni …

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Hydrothermal Carbonization Carbon-Based Acid Catalyst For Biodiesel Production, Laddawan Tumkot Jan 2018

Hydrothermal Carbonization Carbon-Based Acid Catalyst For Biodiesel Production, Laddawan Tumkot

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aims to synthesize the production of biodiesel (oleic acid methyl ester) by esterification in the presence of sulfonated hydrothermal carbon based catalyst under microwave irradiation. The catalyst was prepared by hydrothermal carbonization, followed by sulfonation presenting sulfonic acid group as an active site. The catalyst characterization results confirmed good microwave-absorptivity of the catalyst which can be heated directly and accelerate the reaction immediately at the surface of the catalyst. Esterification of oleic acid (OA) with methanol experiments were optimized by using response surface methodology based on central composite design. Three variables: molar ratio of methanol to OA (2.5:1-7.5:1), …

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Graphene Sheets Decorated With Silver Nanoparticles As An Oxygen Reduction Reaction Catalyst For Zinc-Air Battery, Laksanaporn Poolnapol Jan 2018

Graphene Sheets Decorated With Silver Nanoparticles As An Oxygen Reduction Reaction Catalyst For Zinc-Air Battery, Laksanaporn Poolnapol

Chulalongkorn University Theses and Dissertations (Chula ETD)

The aim of this thesis is to develop a catalyst for the cathode of a zinc-air battery and to investigate the effects of reduced graphene oxide decorated with silver nanoparticles on the cathode in the zinc-air battery. First, reduced graphene oxide (AgNPs/rGO) was synthesized using glucose reduction at 60 degrees Celsius. Next, the structure and morphology of AgNPs/rGO were checked using X-ray diffraction (XRD). Then, transmission electron microscopy (TEM) analyzes were carried out. The amount of silver (Ag) decorate in graphene oxide was confirmed by EDX. Next, the synthesized catalysts at 3 concentration, using a rotating disk electrode (RDE), led …

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Effect Of Cu Modified Tio2 Catalysts Prepared By Incipient Wetness Impregnation And Sputtering For Photocatalytic Co2 Reduction In Aqueous Solution, Nantiya Jantarasorn Jan 2018

Effect Of Cu Modified Tio2 Catalysts Prepared By Incipient Wetness Impregnation And Sputtering For Photocatalytic Co2 Reduction In Aqueous Solution, Nantiya Jantarasorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, we investigated the photocatalytic CO2 reduction in aqueous solution and were carried out in a stirred slurry reactor using Cu/TiO2 catalysts synthesized by incipient wetness impregnation and sputtering method. Effects of Cu loading onto titania support enhancing efficiency of the photocatalytic CO2 reduction in aqueous solution under UV irradiation by a band gap energy modification appeared between valence band and conduction band are narrowed. Cu assisted a selective hydrocarbon compound, this is methane. A comparison between Cu/TiO2 catalysts synthesized by incipient wetness impregnation and sputtering method showed that both methods exhibited similar methane selectivity. Sputtered catalysts are …

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Reactive Extraction Of Metal Ion And Simultaneous Stripping Using Nanofibers-Supported Liquid Membrane In A Microchannel, Nattakarn Chucherd Jan 2018

Reactive Extraction Of Metal Ion And Simultaneous Stripping Using Nanofibers-Supported Liquid Membrane In A Microchannel, Nattakarn Chucherd

Chulalongkorn University Theses and Dissertations (Chula ETD)

Heavy metals in wastewater resulting from industries have become a prime concern for both environmental and economic reasons. This work intends to recover ions of heavy metal from wastewater using reactive extraction by nanofibers-supported liquid membrane (NSLM) in a microchannel. The use of supported liquid membrane enables simultaneous extraction and stripping (i.e., recovery of the extractant) processes. In this study, the NSLM was applied in a microchannel to minimize mass transfer resistance, hence improving overall performance of the extraction. Copper (II) ion was used as a model ion, while di-2-ethylhexyl phosphoric acid (D2EHPA) dissolved in kerosene was used as the …

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Electrode Improvement Using Diamond-Like Carbon For Electrochemical Advanced Oxidation In Diuron Degradation, Nimit Kantiyawong Jan 2018

Electrode Improvement Using Diamond-Like Carbon For Electrochemical Advanced Oxidation In Diuron Degradation, Nimit Kantiyawong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Diuron is one of the pesticides. Its residual can contaminate natural water resource resulting in environmental and human health problems. Several processes have been used to remove diuron contamination. Nowadays, an electrochemical advanced oxidation process (EAOP) in a microchannel reactor is used to degrade diuron owing to its high efficiency. In this research, the diamond-like carbon (DLC) thin film was used as an electrochemical electrode because it has superior hardness and electrical conductivity. In this research, we have successfully synthesized the DLC thin films using graphite as target material on the surface of 304 stainless steel substrate by the direct …

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Computational Fluid Dynamics Modeling Of The Climate Inside A Chicken House, Nuttaphon Kanjanaudomsuk Jan 2018

Computational Fluid Dynamics Modeling Of The Climate Inside A Chicken House, Nuttaphon Kanjanaudomsuk

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, most of chicken products are from a closed house system. Climate inside such chicken house can significantly affect chicken welfare and its productivity. Moreover, Thailand is in a tropical region where thermal stress is easily occurred. Suitable operating condition and chicken house design can help improve interior climate which can be evaluated by computational fluid dynamics (CFD) modeling technique. In this study, realizable k-ε model, energy conservation and species transport equations were applied to simulate the air velocity, temperature and relative humidity, respectively, inside the chicken house. The model was validated with measured air velocity, temperature and relative humidity …

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The Development Of Pt/Wox/Al2o3 For 1,3-Propanediol Production From Glycerol, Parama Uttraporn Jan 2018

The Development Of Pt/Wox/Al2o3 For 1,3-Propanediol Production From Glycerol, Parama Uttraporn

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, the researcher studied the hydrogenolysis of glycerol to 1,3-propanediol, by compared the catalytic activity between AlOOH (boehmite) and g-Al2O3. The catalysts were prepared by wet impregnation method. To investigate the properties, catalysts were characterized by XRD, XPS, BET, H2-TPR, H2-TPD, H2-TPR, SEM-EDX, Py-IR, NH3-IR, and XAS. The type of support showed to be of significance in deciding the activity and the selectivity to 1,3-propanediol. It was found that 2%Pt/WOx/g-Al2O3 gave higher activity and selectivity of 1,3-propanediol, which due to a large amount of active site and Brønsted acid site in the catalyst. The effects of H2 pressure, …

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Effect Of Metal Oxides On Zirconia For Ketonic Decarboxylation Of Methyl Stearate, Pawaphat Sartsri Jan 2018

Effect Of Metal Oxides On Zirconia For Ketonic Decarboxylation Of Methyl Stearate, Pawaphat Sartsri

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this research, the effect of characteristics of zirconia and metal oxide modified zirconia catalysts on the catalytic performance were investigated by ketonic decarboxylation of methyl stearate to desired ketone product at the optimal condition (400°C and 1 bar). Zirconia and metal oxide modified zirconia catalysts were characterized by using X-ray diffraction (XRD), Scanning electron microscope (SEM), N2-physissorption, X-ray photoelectron spectroscopy (XPS), and IR spectra of pyridine adsorption (Pyridine-IR). The results indicated that the transition metal oxide group modified zirconia catalysts have higher contents of total Lewis acid site and oxygen vacancies site, and lower content of total Brønsted acid …

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Regeneration Of Zinc Particles For Zinc-Air Battery By Spouted-Bed Electrochemical Reactor, Peerawat Puengthaijaroen Jan 2018

Regeneration Of Zinc Particles For Zinc-Air Battery By Spouted-Bed Electrochemical Reactor, Peerawat Puengthaijaroen

Chulalongkorn University Theses and Dissertations (Chula ETD)

Zinc-air batteries are a promising energy storage system due to its high energy density, low toxicity, and low flammability. They are currently used commercially in low-current devices. Batteries for high-current applications are constructed with zinc particles for increased specific surface areas. Nevertheless, the regeneration of zinc particles from dissolved zincate ions in spent electrolytes has been relatively neglected. We fabricate and study a spouted-bed electrochemical reactor for the regeneration of zinc particles from spent electrolytes. The reactor measures 220 mm high and 130 mm wide with copper as a cathode and stainless steel as an anode. The reactor is separated …

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Dual-Electrolyte System For Suppressing Corrosion Of Aluminum Electrode In Aluminum-Air Flow Battery, Pemika Teabnamang Jan 2018

Dual-Electrolyte System For Suppressing Corrosion Of Aluminum Electrode In Aluminum-Air Flow Battery, Pemika Teabnamang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Aluminum-air batteries have received considerable attention as an electrical power source due to their theoretical specific capacity reaching 2.98 Ah/g. Further, Al-air batteries are abundant and low cost. On the other hand, the aluminum in the batteries has a problem, such that it is subject to self-corrosion in alkaline. Herein, this work concentrates on the aluminum's corrosive behavior and self-corrosion in methanol-3M KOH mixed solution containing different percentages of deionized water i.e. (0, 5, 10 and 20)%wt, using electrochemical (half-cell testing). The aluminum-air battery consists of: aluminum anode | anolyte | anion exchange membrane | catholyte | air cathode. The …

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Reaction Mechanism And Pathway For The Selective Photocatalytic Hydrogenation Of Nitroaromatics Over Tio2 In Alcohols, Pimchanok Nakchuai Jan 2018

Reaction Mechanism And Pathway For The Selective Photocatalytic Hydrogenation Of Nitroaromatics Over Tio2 In Alcohols, Pimchanok Nakchuai

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research investigated the mechanism and photocatalytic performance of the selective photocatalytic hydrogenation of different nitroaromatics (Ar-NO2) in several alcohols under UV light using P25-TiO2 at room temperature and atmospheric pressure. The effect of Pt-deposited P25-TiO2 on the photocatalytic performance was also studied. Ar-NO2 was converted to aminoaromatics (Ar-NH2) with high Ar-NO2 conversion and Ar-NH2 selectivity at nearly 100%. The amounts of Ar-NH2 were proportional with carbonyl compounds at the ratio around 1:3. Acetaldehyde, acetone, and butanone were produced by oxidation of ethanol, 2-propanol, and butanol, respectively. Ethanol exhibited the fastest completed Ar-NO2 conversion due to the most efficient formation …

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Oxidative Dehydrogenation Of Ethanol To Acetaldehyde Over Magnesium Aluminium Layered Double Hydroxides Catalyst, Piriya Pinthong Jan 2018

Oxidative Dehydrogenation Of Ethanol To Acetaldehyde Over Magnesium Aluminium Layered Double Hydroxides Catalyst, Piriya Pinthong

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this research, the characteristic and catalytic activity of Mg-Al LDH and their metal-modified mixed oxide were investigated. This research was divided into three parts. In the first part, the effect of calcination temperature on catalytic performance via oxidative dehydrogenation of ethanol was elucidated. The results showed that calcination temperature affected the characteristic of Mg-Al LDH, especially basicity. Moreover, the calcination temperature also affected the catalytic performance on oxidative dehydrogenation of ethanol over Mg-Al LDH. The result was consistent with the basicity of catalysts. In the second part, the Mg-Al mixed oxide derived from calcination of Mg-Al LDH was modified …

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Effects Of Immobilization Of Methylalumoxane On Cellulose Support On Ethylene Polymerization Behaviors., Praonapa Tumawong Jan 2018

Effects Of Immobilization Of Methylalumoxane On Cellulose Support On Ethylene Polymerization Behaviors., Praonapa Tumawong

Chulalongkorn University Theses and Dissertations (Chula ETD)

The way to improve the physical properties of polyethylene is done by adding nano-sized filler during the synthetic process. These can be commonly achieved by in situ polymerization. These studies are divided into two parts in this research. Firstly, it investigated the effect of types and amounts of cocatalyst and scavenger of zirconocene catalyst on ethylene polymerization behaviors. In fact, methylalumoxane (MAO) and triethylaluminum (TEA) were used as cocatalyst and scavenger, respectively. The ratios of [Al]MAO/[Zr]cat and [Al]TEA/[Zr]cat were varied during the in situ polymerization of ethylene. The polymerization was performed in a semi-batch autoclave reactor under adiabatic operation at …

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Development Of Suture Pad From Silk-Reinforced Polydimethylsiloxane Composite, Radhitya Banuaji Prastowo Jan 2018

Development Of Suture Pad From Silk-Reinforced Polydimethylsiloxane Composite, Radhitya Banuaji Prastowo

Chulalongkorn University Theses and Dissertations (Chula ETD)

The aim of this research is to investigate the mechanical properties of polydimethylsiloxane reinforced with short silk fibers for suture pad application. The effect of aspect ratio and fibers content of the polydimethylsiloxane reinforced with silk fibers on the properties was evaluated. From the results, tensile modulus and tensile strength of polydimethylsiloxane reinforced with different aspect ratio were increased with increasing aspect ratio and fibers content. The composite with the addition of silk fiber produces higher tear resistance with suture thread compared with pure polydimethylsiloxane. Furthermore, the hardness of polydimethylsiloxane reinforced with short silk fibers was improved with the addition …

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Design Of Solid Oxide Fuel Cell-Molten Carbonate Fuel Cell Combined System For Power Generation And Carbon Dioxide Emission Reduction, Prathak Jienkulsawad Jan 2018

Design Of Solid Oxide Fuel Cell-Molten Carbonate Fuel Cell Combined System For Power Generation And Carbon Dioxide Emission Reduction, Prathak Jienkulsawad

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research concentrates on the design and performance analysis of a solid oxide fuel cell (SOFC) and a molten carbonate fuel cell (MCFC) integrated system with using methane as fuel. Because SOFCs cannot completely use their fuel, there is remaining fuel leaving the system. In addition, the exhaust gas from an SOFC can be directly fed into an MCFC. The integrated fuel cell system shows an electrical efficiency of 55.22%, which is higher than a single fuel cell system. Fuel utilization of both fuel cells, SOFC temperature dramatically affect the performance of the integrated system. Four configurations were next proposed …

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Effect Of Calcination Conditions Of P25-Tio2 On Photocatalytic Selective Hydrogenation Of 3-Nitrostyrene, Saknarin Chaitaworn Jan 2018

Effect Of Calcination Conditions Of P25-Tio2 On Photocatalytic Selective Hydrogenation Of 3-Nitrostyrene, Saknarin Chaitaworn

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, we investigated the effect of calcination of nanocrystalline commercial titanium dioxide catalyst (P25) on photocatalytic selective hydrogenation of 3-nitrostyrene. TiO2 supports were calcined under air, hydrogen and nitrogen atmosphere at various temperatures around 600 to 900°C for 5 hours. In order to investigate characteristic and catalytic properties of TiO2 after treatment, treated-TiO2 were analyzed by using X-ray diffraction (XRD), N2-physisorption, X-ray photoelectron spectroscopy (XPS), UV-Vis spectroscopy (UV-Vis), photoluminescence spectroscopy (PL), thermogravimetric analysis (TGA), scanning electron microscope (SEM). Photocatalytic hydrogenation performance of treated-TiO2 were tested under UV light irradiation. The 3-nitrostyrene consumption was linearly related to the photoluminescence …

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Synthesis Of Black Titanium Dioxide And Effect Of Calcination Conditions And Reducing Agent On Photocatalytic Degradation Of Methyl Orange, Saran Saensook Jan 2018

Synthesis Of Black Titanium Dioxide And Effect Of Calcination Conditions And Reducing Agent On Photocatalytic Degradation Of Methyl Orange, Saran Saensook

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research studied the synthesis and application of black titanium dioxide in the photocatalytic degradation of methyl orange (MO). First, titanium dioxide was prepared via a sol-gel method. Then sodium borohydride was used as the reducing agent in order to synthesize black titanium dioxide. Thus, a 2x2x3 factorial experimental design was employed to assess the significance of the following three factors: (A) calcination temperature (400 and 500 °C); (B) calcination time (5 and 10 h); and (C) the molar ratio of NaBH4 to TiO2 used (0:1, 0.5:1, and 1:1). The removal of MO under UV and visible light were the …

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