Chemical Engineering Commons^™

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 …

Fundamental Aspects Of A Novel Technology For Abatement Of Indoor Allergens, Odell Lendor Glenn Jr.

Theses and Dissertations

The overall goal of this research was to develop a novel approach to reduce the potency of certain asthma triggers, namely, proteins produced by pests or pets in indoor environments. The broad hypothesis of the research was that naturally occurring essential oils will demonstrate enhanced denaturing ability. In any indoor environment, allergens are bound to dry dust particles. In this work, the effectiveness of using dry ice and CO2 with potential for essential oils on dry allergenic proteins through CFD modeling and ELISA methods were evaluated.

There are three objectives central to this work. The first objective was to apply …

Graphene As A Solid-State Ligand For Palladium Catalyzed Cross-Coupling Reactions, Yuan Yang

Theses and Dissertations

Palladium-catalyzed carbon-carbon cross-coupling reactions have emerged a broadly useful, selective and widely applicable method to synthesize pharmaceutical active ingredients. As currently practiced in the pharmaceutical industry, homogeneous Pd catalysts are typically used in cross-coupling reactions. The rational development of heterogeneous catalysts for cross-coupling reactions is critical for overcoming the major drawbacks of homogeneous catalysis including difficulties in the separation, purification, and quality control process in drug production. In order to apply heterogeneous catalysis to flow reactors that may overcome this limitation, the catalyst must be strongly bound to a support, highly stable with respect to leaching, and highly active. While …

The Rational Synthesis Of Bimetallic Catalysts On Oxide Supports, Andrew Phillip Wong

Theses and Dissertations

Catalysts play an important role in many chemical reactions. However, simple impregnated monometallic catalysts are often limited in their function. One way to overcome this limitation is through the incorporation of a secondary metal to the catalysts. These bimetallic catalysts often have synergistic benefits not observed in the monometallic analogues. Here, we focused on the synthesis of bimetallic catalysts using rational methods in order to improve catalyst function; specifically by tuning the particle size, morphology, and composition. The two methods of interests were Strong Electrostatic Adsorption (SEA) and Electroless Deposition (ED). An adaptation of SEA to bimetallic catalysts (coSEA) was …

A Novel Supercritical Co2-Based Decellularization Method For Maintaining Scaffold Hydration And Mechanical Properties, Michael A. Matthews, Tarek Shazly, Rachel M. Handleton, Dominic M. Casali

Faculty Publications

Decellularized tissues are commonly utilized as tissue engineering scaffolds. Decellularization by extended exposure to aqueous detergents can damage the microstructure or deposit cytotoxic residue. Supercritical carbon dioxide (scCO2) has been proposed for decellularization, but reportedly causes dehydration and scaffold embrittlement.

Presented herein is a novel decellularization method that preserves matrix hydration state and mechanical properties. Over 97% of the water in porcine aorta is maintained by presaturating scCO2 with water; however, complete decellularization was not attained by any process utilizing only scCO2. Instead, a novel hybrid method is presented that combines a brief (48 h) exposure of tissue to aqueous …

Ore Reserves Estimation Of The Nam Nga Coal Deposit, Lao Pdr, Using Geostatistical Method, Tongvang Bliachongvang

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research study focuses on estimating the coal deposit quantity and qualities as CV and AC at Nam Nga coal deposit, Lao PDR using OK and SGS geostatistical methods. A total of 295 assays data from 51 exploration drill holes collected from LID Company were used. The results reveal that OK produces geological resource of 2.2 MT with an average CV of 3,733 kcal/kg and an average AC of 48.68 %. The mineable reserve computed from OK's ultimate pit design and pit adjustment are 0.55 MT. The OK method produces 9.32 MT of wastes, yielding a stripping ratio of 10.4:1. …

Green-House Gas Storage Through Enhanced Hydrate Formation, Thiphakorn Absuwan

Chulalongkorn University Theses and Dissertations (Chula ETD)

The CO₂ hydrate formation in the presence of different tetrahydrofuran (THF), sodium dodecyl sulfate (SDS), and methyl ester sulfonate (MES) concentrations was investigated in terms of kinetics and thermodynamics. The formation experiment was conducted in the quiescent condition and close system at 3 MPa and 3 °C. The results showed that the CO₂ hydrates formed in the presence of 10 mol% THF, while it did not form with 5.56 mol% THF. The presence of SDS or MES did not promote the hydrate formation. However, the hydrates formed in the presence of a mixture of SDS or MES with 5.56 mol% …

Optimization Algorithm Study : Mixed Integer Linear Programming, Tittawat Fongchantuk

Chulalongkorn University Theses and Dissertations (Chula ETD)

In the present, many petrochemical and petroleum products (engine fuel, solvent, plastic and synthetic rubber. etc.) are important. They are transported by ship, pipe line or train every day. So, minimizing transportation cost and time or maximizing profit is an important key of every company. In this optimization process, the optimal supply chain must be well developed in mathematical programming with the objective function of minimum cost or maximum profit and be solved by using optimization solvers. Objective functions and their constraints are solved by suitable types of optimization solvers: Linear programming (LP) and mixed integer linear programming (MILP). MILP …

Ethanol Dehydration With Oxygen Cofeeding Over Palladium Catalyst Supported On Spherical Silica Particle With Ceria Modification, Kanjanee Sinchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Ethanol dehydration with oxygen cofeeding over palladium catalyst supported on spherical silica particle with ceria modification was carried out in fixed bed reactor under atmospheric pressure and temperature range of 150 ˚C to 350 ˚C (O2/Ethanol molar ratio = 2.2). The results showed that the effect of ceria modification of Pd/CeO2/SSP catalyst exhibited higher activity than Pd/SSP and CeO2/SSP at 200 ˚C. Pd/CeO2/SSP catalyst yielded very the high ethanol conversion at 200 °C about 57.7 %. However, the preparation method with different sequence of loading has significant effects on crystallite size, surface area, H2-TPR profile and catalytic activity. Pd-CeO2/SSP was …

Dehydration Of Ethanol To Diethyl Ether Over Beta Zeolite Catalysts, Montri Thapplee

Chulalongkorn University Theses and Dissertations (Chula ETD)

The catalytic ethanol dehydration to diethyl ether was investigated using synthesized beta zeolite catalysts having different Na and mixed Na-H form. The Na form in catalyst was synthesized by the hydrothermal process including non-calcined (Na-BEA_N) and calcined (Na-BEA_C) catalysts. The catalysts having different mixed Na-H forms were synthesized under ion-exchange method. In this study, two different cycles were chosen including one cycle (M-BEA_1) and four cycles (M-BEA_4). These catalysts were characterized by various techniques. The catalysts were tested to measure the catalytic activity at atmospheric pressure and the reaction temperature ranged from 150 to 400 °C. The results presented that …

Analysis And Design Of Vanadium Redox Flow Battery, Tossaporn Jirabovornwisut

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, the dynamic model of a vanadium redox flow battery (VRFB) was developed to analyze the battery performance and capacity degradation caused by an electrolyte imbalance from hydrogen and oxygen evolution and self-discharge side reactions. The model-based analysis of the VRFB performance revealed that the rate of battery capacity loss resulting from the electrolyte imbalance considerably depended on electrode and membrane material as well as operating conditions. Self-discharge reactions were controlled by the operational time of the battery. In addition, the rate of capacity degradation increased with an increase in the total vanadium concentration and operating temperature, affecting …

Designing Binary Low Ift Surfactant System Using Hld Concept For Oil Recovery, Tukta Jamprakhon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Surfactant-based microemulsion technology is widely used in tertiary enhanced oil recovery applications (EOR). The formulation of suitable surfactant system is a key success in production and economic feasibility of this technology. The middle phase or Winsor Type III microemulsions, employed for selecting appropriate surfactant system, can offer an optimal salinity at which the high oil solubilization capacity and minimum interfacial tension (IFT) or ultralow IFT (<0.01 mN/m) are obtained. By this technology, more remaining oil in the reservoir can be solubilized and mobilized which leads to an improvement of oil recovery. This study aims to formulate surfactant systems for the oil recovery through microemulsion formulation. The novel mixed anionic surfactant system of a sodium dioctyl sulfosuccinate (AOT) and an internal olefin sulfonates (IOS) with different alkyl chain lengths (C15-18, C19-23, C24-28) were used due to its mixture avoiding the surfactant precipitation. The result found that the binary mixture of AOT and (IOS C15-18 and IOS C19-23) can form the middle phase at the mixing ratios of 5:5 to 9:1 (by molar ratio) with heptane and decane. When the fraction of IOS increased in the mixed AOT/IOS system, the optimal salinity (S*) also increased. For the effects of a carbon tail length of IOS surfactant was observed that the tail length increased with decreasing the optimal salinity. The hydrophilic-lipophilic deviation (HLD) for the mixed surfactant system was investigated to individually determine the K and Cc values for the IOS surfactants. The finding from this work provided a guide for surfactant selection through HLD concept to formulate microemulsion-based surfactant flooding for EOR application.

Design Of Plantwide Control Structure Of Double Effect Water/Lithium Bromide Absorption Chiller, Kris Prasopsanti

Chulalongkorn University Theses and Dissertations (Chula ETD)

Alternative control structures for a parallel double effect aqueous lithium bromide absorption chiller, operated in two modes of operation, has been designed using Skogastad's plantwide control procedure. In on-demand mode, two complete decentralized control structures with proportional integral (PI) controllers and one structure with a two inputs - two outputs model predictive controller (MPC) were proposed. Their performance was evaluated using MATLAB-Simulink dynamic simulation. The results varied depended on type of disturbance, but overall, the structure with MPC controller provided slightly better results with less liquid holdup changes and faster setting time in average. For on-supply mode, two self-optimizing control …

The Effects Of Tio2 Phase And Sio2 Supports On Methyl Oleate Epoxidation, Nichaphat Sangkanchanavanich

Chulalongkorn University Theses and Dissertations (Chula ETD)

This work studies about the epoxidation reaction of methyl oleate with TiO2 or TiO2/SiO2 catalysts and hydrogen peroxide. Study of TiO2 catalysts interests in catalysts from commercial and sol gel method. The highest catalytic activity and selectivity of TiO2 from commercial is TiO2 commercial type B which gives 46.10% and 79.75%, respectively. For sol gel method, the highest catalytic activity at 75.82% and selectivity at 90.85% is TiO2 calcination temperature at 300OC, due to low crystallinity and high surface area. TiO2/SiO2 with different type of SiO2 support (MCM-41, SBA-15, silicalite, silica gel and fumed silica) shows different catalytic activity and …

Hydrogen Production From Sorption Enhanced Chemical Looping Steam Ethanol Reforming Using Calcium Oxide/ Copper Oxide/ Nickel Oxide Multifunctional Catalyst, Talita Nimmas

Chulalongkorn University Theses and Dissertations (Chula ETD)

Multifunctional catalyst was developed for hydrogen production via sorption enhanced chemical looping ethanol steam reforming. Calcium acetate (Ca2Ac) and calcium chloride (CaCl) were used as calcium precursor. Sodium carbonate (Na2CO3) and urea (CO(NH2)2) were used as carbonate precursor. The NiO/CaOAc-Urea-Ca12Al14O33 showed the longest pre-breakthrough period of 60 min and 88% of hydrogen purity at steam to ethanol molar ratio (S/E) of 4:1, temperature 600 ﹾC. Stability of NiO/CaOAc-Urea-Ca12Al14O33 was tested over 10 cycles and the results showed hydrogen purity can be maintained at 90% during pre-breakthrough period. The effect of synthesis method: sol-mixing and sol-gel, on hydrogen production was compared …

The Surface Modification Of Zeolite Y In Composite Selective Layer Of Hollow Fiber Membrane For Separation Of Co2/Ch4 Mixture, Thakorn Wichaidit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This work focused on the fabrication and evaluation of composing hollow fiber mixed matrix membranes (MMMs) incorporated by zeolite Y for CO2/CH4 separation. The effects of surface modification of zeolite Y to improve compatibility of filler and polymer dispersibility of the filler in the polymer matrix on properties and separation performance of the membrane were investigated. A polysulfone (PSF) was used as a support hollow fiber and a selective layer composing of polyether-block-amide (Pebax) and zeolite Y (ZeY) and surface modification of zeolite Y (mo-ZeY) was coated on support. A [3-(2-Aminoethylamino)propyl]trimethoxysilane (AEAPTMS) was used to grafted on surface of pristine …

การพัฒนาฟิล์มบรรจุภัณฑ์บรรยากาศดัดแปรจากสารผสมระหว่างพอลิเอธิลีนชนิดความหนาแน่นต่ำกับเทอร์โมพลาสติกพอลิเอสเทอร์อีลาสโตเมอร์, กันตพงศ์ สักลอ

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้เป็นการพัฒนาฟิล์มบรรจุภัณฑ์บรรยากาศดัดแปร (Modified Atmosphere Packaging Film) โดยศึกษาถึงผลของปริมาณสารเทอร์โมพลาสติกพอลิเอสเทอร์อิลาสโตเมอร์ (TPEE) ในสัดส่วน 0 - 50% โดยน้ำหนักที่ถูกผสมเข้าไปในพอลิเอธิลีนชนิดความหนาแน่นต่ำ (LDPE) และสภาวะการขึ้นรูปฟิล์ม ได้แก่ อัตราเร็วในการดึงฟิล์ม (Film Pulling Speed) ช่วง 200 - 240 rpm และอุณหภูมิหล่อเย็นฟิล์ม 15 - 50 องศาเซลเซียสต่อค่าความสามารถในการซึมผ่านแก๊สและไอน้ำของฟิล์มที่ได้ ผลการทดลองพบว่าการเติม TPEE ลงใน LDPE ในปริมาณที่มากขึ้นส่งผลให้ความสามารถในการซึมผ่านไอน้ำและแก๊สของ MAP Film มีแนวโน้มเพิ่มขึ้น เพราะ TPEE มีความสามารถในการซึมผ่านไอน้ำและแก๊สสูงกว่า LDPE นอกจากนี้การเพิ่มอัตราเร็วในการดึงฟิล์มส่งผลทำให้ช่องว่าง (Void) บริเวณรอยต่อระหว่างวัฏภาคของ LDPE กับ TPEE กว้างขึ้น ส่งผลให้อัตราการซึมผ่านของไอน้ำและแก๊สเพิ่มขึ้นตามไปด้วย ในทางกลับกัน การเพิ่มอุณหภูมิหล่อเย็นฟิล์มส่งผลให้เปอร์เซ็นต์ความเป็นผลึกของฟิล์มเพิ่มขึ้น ทำให้อัตราการซึมผ่านของไอน้ำและแก๊สมีแนวโน้มลดลง ส่วนการทำนายเวลาที่แก๊สในถุงบรรจุภัณฑ์เข้าสู่สภาวะคงตัวและปริมาณแก๊สในถุงบรรจุภัณฑ์โดยใช้โปรแกรม MATLAB พบว่า ภายใต้สภาวะที่ศึกษา แก๊สในถุงบรรจุภัณฑ์เข้าสู่สภาวะคงตัวภายในเวลา 24 ชั่วโมง โดยที่ MAP Film ที่มีค่าความสามารถในการซึมผ่านแก๊สออกซิเจนสูงกว่า ทำให้ปริมาณแก๊สออกซิเจนภายในถุงบรรจุภัณฑ์ที่สภาวะคงตัวมีค่าสูงกว่าและในทางกลับกัน MAP Film ที่มีค่าความสามารถในการซึมผ่านแก๊สคาร์บอนไดออกไซด์สูงกว่า ทำให้แก๊สคาร์บอนไดออกไซด์ภายในถุงบรรจุภัณฑ์ที่สภาวะคงตัวมีค่าน้อยกว่า

Developing A 3d In Vitro Model By Microfluidics, Hung-Ta Chien

Dissertations and Theses

In vitro tissue models play an important role in providing a platform that mimics the realistic tissue microenvironment for stimulating and characterizing the cellular behavior. In particular, the hydrogel-based 3D in vitro models allow the cells to grow and interact with their surroundings in all directions, thus better mimicking in vivo than their 2D counterparts. The objective of this thesis is to establish a 3D in vitro model that mimics the anatomical and functional complexity of the realistic cancer microenvironment for conveniently studying the transport coupling in porous tissue structures. We pack uniform-sized PEGDA-GelMA microgels in a microfluidic chip to …

Understanding Of Molecular Interactions And Reversibility In Silylamines, Josephine Chen

Dissertations and Theses

Modern Li-ion batteries employ flammable electrolytes that pose safety concerns. Battery safety has become important as several incidents involving Li-ion battery fires have been observed. This issue could be addressed through a switchable battery electrolyte. Reversible ionic liquids (RevILs) could be used in such an electrolyte that would cease operation in the event of rapid temperature elevation because they can switch between states of drastically different properties upon the application of an external stimulus, such as temperature or CO₂ addition. Silylamines, in particular, are a class of thermally responsive RevILs that are conducting in its ionic liquid (RevIL) state …

Study Of Gas Production From Shale Reservoirs With Multi-Stage Hydraulic Fracturing Horizontal Well Considering Multiple Transport Mechanisms, Chaohua Guo, Mingzhen Wei, Hong Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Development of unconventional shale gas reservoirs (SGRs) has been boosted by the advancements in two key technologies: horizontal drilling and multi-stage hydraulic fracturing. A large number of multi-stage fractured horizontal wells (MsFHW) have been drilled to enhance reservoir production performance. Gas flow in SGRs is a multi-mechanism process, including: desorption, diffusion, and non-Darcy flow. The productivity of the SGRs with MsFHW is influenced by both reservoir conditions and hydraulic fracture properties. However, rare simulation work has been conducted for multi-stage hydraulic fractured SGRs. Most of them use well testing methods, which have too many unrealistic simplifications and assumptions. Also, no …

Toxicological Inhalation Effects Of Metal-Based Nanoparticle Aerosols As Studied By A Portable In Vitro Exposure Cassette, Lynn E. Secondo

Theses and Dissertations

The toxicology of aerosols in occupational settings is often performed through particle collection on a filter followed by reconstitution into cell culture media which can alter the biological effects. Current in vitro exposure systems require additional instruments to control temperature and humidity, making the system bulky and difficult to take to the field. The Portable In Vitro Exposure Cassette (PIVEC) was designed for personal monitoring, characterized using copper nanoparticles, tested with alveolar cells, and set-up for real-time monitoring. Three differently sized copper nanoparticles, 40-800 nm, were dispersed as a dry aerosol and measured gravimetrically and on a number concentration basis …

An Integrated Method For Forecasting Well Deliverability In Gas Condensate Reservoirs With Bottom Aquifer Drive, Abdulaziz Ellafi, Ralph E. Flori, Shari Dunn-Norman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Gas condensate reservoirs constitute a significant portion of global hydrocarbon reserves. In these reservoirs, liquids develop in the pore space once bottomhole pressure falls below dew point. This results in the formation of a liquid bank near the wellbore region which decreases gas mobility, which then reduces gas inflow. In such complex reservoirs, it is important to correctly describe PVT impacts, adjustments to well test analysis and inflow performance, and then combine all effects in the reservoir analysis. The literature contains many references to individual adjustments of PVT analysis, well testing, or inflow performance for gas condensate reservoirs, but few …

Learning From Experience: An Automatic Ph Neutralization System Using Hybrid Fuzzy System And Neural Network, Ethar H.K. Alkamil, Seaar Al-Dabooni, Ahmed K. Abbas, Ralph Flori, Donald C. Wunsch

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In oil and gas industry, the pH level is one of the most important indicators of mud contamination while drilling. Although the process has simple components, the pH neutralization process is complicated in the mud circulation system. This difficulty is due to the high nonlinearity of the process. In this paper, the fuzzy neural network (FNN) is integrated to the fuzzy logic controller (FLC) to create a system which identifies pH fluctuation into a drilling mud system, assesses and signals its severity. And then, it automatically actuates a chemical treating fluids valve (CTFV), such as Caustic Soda (CS), for neutralizing …

Metabolic Engineering Of Serratia Marcescens, Qiang Yan

Theses and Dissertations

The potential value of the chitin biomass (e.g. food waste) is recently considered being ignored by landfill. Chitin can be a potential cheap carbon source for converting into value-added chemicals by microorganisms. Serratia marcescens is a chitinolytic bacterium that harbors endogenous chitinase systems. With goals of characterzing S. marcescens chitinolytic capabilities and applying S. marcescens to chemical production from chitin, my dissertation main content includes five chapters: 1) Chapter 1 highlights background information of chitin source, S. marcescens and potential metabolic engineering targets using chitin as a substrate; 2) Chapter 2 demonstrates that ChiR is a key regulator in regulating …

Process Optimization For The Synthesis Of Gold Nanoparticles From A Mixed Metal Precursor Solution, Kathryn Ann Dill

Theses and Dissertations

Separation methods involving a mixture of metals typically include upfront processing that leads to one final product. To lower the waste and ultimately environmental burden, the potential to synthesize multiple functional products from a mixed metal precursor solution is explored. The initial precursor solutions contained varying ratios of gold and copper, gold and nickel, and finally a ternary solution of gold, copper, and nickel. The amount of gold was kept constant, while the amount of copper and/or nickel was sequentially increased. Two separate synthesis processes were tested, the traditional Turkevich method involving trisodium citrate and another chemical reduction method involving …

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 …

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, …

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 …

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 …

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 …