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2017

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Tyrosinase Inhibitors From Bark Of Talawrinta (Manilkara Kauki (L.) Dubard, Sirinada Srisupap Jan 2017

Tyrosinase Inhibitors From Bark Of Talawrinta (Manilkara Kauki (L.) Dubard, Sirinada Srisupap

Chulalongkorn University Theses and Dissertations (Chula ETD)

Melanin is essential for protecting human skin from ultraviolet radiation. However, its overproduction in the basal epithelial layer leads to hyperpigmentary disorders of the skin such as melasma, blemish and age spots. Tyrosinase is one of key enzymes in melanogenesis. Manilkara kauki (L.) Dubard or Talawrinta is one of the plants in genus Manilkara of Sapotaceae family. This study attempted to investigate in vitro total phenolic and flavonoid contents, antioxidant and tyrosinase inhibitory activities of crude extract of different parts of M. kauki and purify tyrosinase inhibitors from stem barks of M. kauki. Methanol and aqueous crude extracts of fruits, …

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Bioactive Compounds From Songkhla Province Mangrove-Derived Endophytic Fungi And From Heart-Leaved Moonseed Tinospora Baenzigeri Forman, Sujitra Hanthanong Jan 2017

Bioactive Compounds From Songkhla Province Mangrove-Derived Endophytic Fungi And From Heart-Leaved Moonseed Tinospora Baenzigeri Forman, Sujitra Hanthanong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study has evaluated biological activities of isolated compounds from Tinospora baenzigeri stems collecting from two different areas, and from mangrove-derived endophytic fungi isolated from trees inhabiting in Songkhla province. Four new rearranged clerodane-type diterpenes (66-69), one new glycoside (70), and six known compounds (61, 71-75), were extracted from plant obtained from local market in Bangkok. Twelve compounds including a new rearranged clerodane-type diterpene (76), a new rearranged clerodane glycoside (77), five known compounds (44, 78-81), and five compounds counting 61, 66, 70 and 74-75 were obtained from plant collected in Bueng Kan Province. Structures of new compounds 66-69 and …

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Increasing Viability Of Probiotic Bacteria Co-Encapsulated With Prebiotic For Disease Resistance In White Shrimp Litopenaeus Vannamei, Suppharada Jantarathin Jan 2017

Increasing Viability Of Probiotic Bacteria Co-Encapsulated With Prebiotic For Disease Resistance In White Shrimp Litopenaeus Vannamei, Suppharada Jantarathin

Chulalongkorn University Theses and Dissertations (Chula ETD)

The main problem of probiotics is the low survival of these microorganisms in food products and sensitive to harsh conditions during food processing, storage and in the gastrointestinal tract. The suitable technology for protecting probiotics to maintain the high number of probiotic cells in product and survived within the host which is microencapsulation technique. The aim of this work was to investigate the effect of prebiotic which is inulin or Jerusalem artichoke on the survival of encapsulated Lactobacillus acidophilus TISTR 1338 within alginate matrix and double-coated with chitosan after freeze-drying process and heat processing at 70°C for 60 min. Furthermore, …

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Optimization Of Preparation Protein Hydrolysate By Protease G6 Using Response Surface Methodology And Free Radical Scavenging Activities From Feather Meal, Waleeporn Pibulpol Jan 2017

Optimization Of Preparation Protein Hydrolysate By Protease G6 Using Response Surface Methodology And Free Radical Scavenging Activities From Feather Meal, Waleeporn Pibulpol

Chulalongkorn University Theses and Dissertations (Chula ETD)

The aim of this research was to study the optimal condition for chicken feather meal protein hydrolysate production using a microbial protease, Protease G6. The experimentation was conducted using Central Composite Design (CCD) and Response Surface Methodology (RSM). The three independent variables including temperature (°C), time and enzyme-substrate ratio were studied. Optimization process for obtaining high yield of chicken feather meal protein hydrolysate was performed using response surface methodology (RSM) by optimizing a combination of three independent variables namely, temperature (41.59 – 58.41°C), time (0:38 - 7:21 h) and enzyme-substrate ratio (0.8 – 9.2) with degree of hydrolysis (DH) as …

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Tyrosinase Inhibitors From Sapodilla Plum Manilkara Zapota L., Sutthiduean Chunhakant Jan 2017

Tyrosinase Inhibitors From Sapodilla Plum Manilkara Zapota L., Sutthiduean Chunhakant

Chulalongkorn University Theses and Dissertations (Chula ETD)

Six different parts of Manilkara zapota which consisted of barks, flowers, fruits, leaves, roots and seeds were investigated for total phenolic content, total flavonoid content, antioxidant and antityrosinase activities. Methanol crude extract of flowers showed the highest total phenolic content (368.73 ± 0.65 mg GAE/g), while methanol crude extracts of seeds and roots showed high total flavonoid content (90.21 ± 0.57 and 89.03 ± 1.00 mg QE/g, respectively). Methanol crude extract of seeds showed the strongest DPPH (IC50 282.05 ± 0.60 μg/mL) and ABTS (IC50 205.11 ± 0.89 μg/mL) radical scavenging activities and showed the highest FRAP value of 296.46 …

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Optimization Of D-Lactic Acid Production By Terrilactibacillus Laevilacticus Sk5-6 And Fermentation Process Scale Up In 30 Litre-Fermentor, Woraphot Toliang Jan 2017

Optimization Of D-Lactic Acid Production By Terrilactibacillus Laevilacticus Sk5-6 And Fermentation Process Scale Up In 30 Litre-Fermentor, Woraphot Toliang

Chulalongkorn University Theses and Dissertations (Chula ETD)

PLA, which is one of biodegradable plastic stereocomplex is made by block polymerization of optically pure L- and D-lactic acid. With stereoblock structure, heat and mechanical properties of PLA products can be improved. Thus, the demand of D-lactic acid has been increased. However, the market supply is still limited. In-house work reported that Terrilactibacillus laevilacticus SK5-6, the novel bacterium has been isolated from soil and later identified as the potent D-lactic acid producer. Moreover, it could produce high D-lactic acid from glucose with high optical purity in flask scale. To improve the fermentation performance, further process optimization was conducted in …

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Malfunctioned Pacemaker And Business Operator's Liability In Us, Eu And Australia: Implication For Thailand, Peerasak Ounhachoke Jan 2017

Malfunctioned Pacemaker And Business Operator's Liability In Us, Eu And Australia: Implication For Thailand, Peerasak Ounhachoke

Chulalongkorn University Theses and Dissertations (Chula ETD)

At the present time, for the purpose of healthcare, pacemakers and other implantable medical devices are playing a significant role. However, the severity of level of damage arising from a malfunctioning pacemaker may be higher when compared with other simple products because when taking into consideration the characteristics and purpose of a pacemaker, it was normally implanted into a patient's body to control an abnormal heartbeat rate; therefore, a malfunctioned pacemaker may potentially cause harmful consequences, and in the worst scenario, death. From the abovementioned issue, the aspects of this research focused on the evolution of the laws and regulations …

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Legal Measures For Employer To Reach Fair Practice In Organizational Restructuring In Thailand, Pitsanuchai Thongtha Jan 2017

Legal Measures For Employer To Reach Fair Practice In Organizational Restructuring In Thailand, Pitsanuchai Thongtha

Chulalongkorn University Theses and Dissertations (Chula ETD)

Restructuring, a normal managerial task of entrepreneurship, can lift up an enterprises' competitiveness potential in business societies. Restructuring will affect to the rights of all people in the enterprise. Labor laws and regulations not only provide adequate protection for employees, but also promote the flexibility to the business sectors. The employment relationships are involved with the actions of three parties - employees, employers and the government - that must substantially cooperate in order to establish efficient labor regulations. Thai labor laws which relate to working condition adjustment and dismissal are obsolete. It provides too much power for the courts in …

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Diversity Of Mosses In Phu Kradueng National Park, Loei Province, Patsakorn Ajintaiyasil Jan 2017

Diversity Of Mosses In Phu Kradueng National Park, Loei Province, Patsakorn Ajintaiyasil

Chulalongkorn University Theses and Dissertations (Chula ETD)

The study of mosses diversity in Phu Kradueng National Park, Loei Province was explored from December 2014 to December 2016. The samples were collected along the 6 natural trails. A total of 501 samples were identified into 30 families, 55 genera, 100 species, 5 subspecies, and 9 varieties. Three families of mosses namely Sphagnaceae, Fissidentaceae, and Leucobryaceae were common families which included 11, 9 and 7 taxa, respectively. Additionally, the most common microhabitat was saxicolous with 45 species. The second and third common microhabitats were terrestrial and corticolous with 43 and 37 species, respectively. Additionally, there are 4 species which …

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Catalytic Ethanol Dehydration To Diethyl Ether Over Palladium-Modified Phosphorus Gamma Alumina Catalysts, Chakkrit Khaochartchai Jan 2017

Catalytic Ethanol Dehydration To Diethyl Ether Over Palladium-Modified Phosphorus Gamma Alumina Catalysts, Chakkrit Khaochartchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

The gamma alumina (γ-Al2O3) catalyst was modified with phosphorous (P) by acid activation technique and palladium (Pd) by the incipient wetness impregnation technique. The obtained catalysts were characterized with various techniques including X-ray diffraction (XRD), inductively coupled plasma (ICP), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX), N2 physisorption, ammonia temperature-programmed desorption (NH3-TPD), and thermogravimetric analysis (TGA). In addition, these modified catalysts were tested in ethanol dehydration reaction in a fixed-bed microreactor to determine ethanol conversion and product yield at the atmospheric pressure with temperatures ranging from 200-400oC. From the results, the phosphorous modification diminished the amount of …

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Co2 Methanation Over Nial2o4 Spinel - Based Catalysts, Chanya Thamma Jan 2017

Co2 Methanation Over Nial2o4 Spinel - Based Catalysts, Chanya Thamma

Chulalongkorn University Theses and Dissertations (Chula ETD)

In the present work, a series of NiO/NiAl2O4 catalysts were prepared by co-precipitation method with molar ratio of Ni/Al equal 1/2 at different precipitation temperatures (30 and 80oC) and calcination temperatures (500, 700, 900, and 1200oC). The catalyst properties were characterized by using N2 physisorption, X-ray diffraction, H2 - TPR, SEM, and TEM. The NiO/NiAl2O4 precipitated at 80oC and calcined at 900oC showed the best activity in CO2 methanation at 350oC with conversion 92% and 100% methane selectivity without CO formation. The optimal of NiO and NiAl2O4 composition at 24.7% and 75.3%wt could provide a stabilizing effect preventing the metal …

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Dehydration And Oxidative Dehydrogenation Of Ethanol Over Sba-15 Based Catalysts Prepared By Sol-Gel And Hydrothermal Methods, Chaowat Autthanit Jan 2017

Dehydration And Oxidative Dehydrogenation Of Ethanol Over Sba-15 Based Catalysts Prepared By Sol-Gel And Hydrothermal Methods, Chaowat Autthanit

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this present study, characteristics and catalytic properties of zirconium (Zr) and bimetal (Zr and La) containing in SBA-15 catalysts and different VOx/SBA-15 catalysts were determined and well related. The study was divided into three parts. Regarding to the first part, zirconium (Zr) and bimetal (Zr and La) containing in SBA-15 synthesized by sol-gel and hydrothermal methods were compared. The results showed that the incorporation of Zr and bimetal (Zr and La) had an effect on the textural properties of both synthesized SBA-15 catalysts. Surface acidity in the SBA-15 suggests new active sites, especially Brønsted acid type. In the second …

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Functionalization Of Carbon Nanohorns And Their Catalysis Applications, Chompoopitch Termvidchakorn Jan 2017

Functionalization Of Carbon Nanohorns And Their Catalysis Applications, Chompoopitch Termvidchakorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Carbon nanohorns (CNHs) synthesized by gas-injected arc-in-water method were functionalized in this study. Metal (Ni, Cu, Fe, Pd, and Pt) and their alloy (NiCu, NiFe, NiPd, and NiPt) hybridized with CNHs were successfully produced. In addition, thermal and acid treatment was applied on the hybridized materials. Effect of metal loading and functionalizing conditions on characteristics of CNHs and functionalized CNHs was examined based on transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), N2 sorption, Raman spectroscopy, Fourier transform infrared (FT-IR) spectrometer, temperature programmed desorption of ammonia (NH3-TPD) analysis. The functionalized CNHs were applied as a catalyst in …

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Conversion Of Glucose To Levulinic Acid By Fe/Carbon Nanoparticle Catalyst Synthesized From Lubricant Oil And Ferrocene, Jirarat Kaewngam Jan 2017

Conversion Of Glucose To Levulinic Acid By Fe/Carbon Nanoparticle Catalyst Synthesized From Lubricant Oil And Ferrocene, Jirarat Kaewngam

Chulalongkorn University Theses and Dissertations (Chula ETD)

Currently, production of levulinic acid which is one of promising chemical substances derived from biomass has been intensively investigated. Different catalyst types have been employed to produce levulinic acid from glucose including zeolite, metal phosphate and alumina. However, carbon based catalysts with high thermal stability, ease of surface functionalization and acid-base resistance were not widely studied. In this thesis, carbon nanoparticles synthesized from lubricant oil and ferrocene via co-pyrolysis was fully studied for glucose conversion to levulinic acid. The effect of carbon nanoparticles acid treatment was mainly investigated in terms of glucose conversion and levulinic acid yield. Pristine magnetic carbon …

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Effects Of Carbon Fiber And Glass Fiber On Shape Memory Polymers Based On Benzoxazine-Epoxy Binary Systems, Jutamart Plylaharn Jan 2017

Effects Of Carbon Fiber And Glass Fiber On Shape Memory Polymers Based On Benzoxazine-Epoxy Binary Systems, Jutamart Plylaharn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Recovery stress is an important parameter of shape memory polymers. Generally, recovery stress in SMPs can be enhanced by using fiber reinforced composites with suitable reinforcing agents such as carbon fiber or glass fiber. We aim to study effects of carbon fiber and glass fiber on thermal, mechanical, and shape memory properties of benzoxazine-epoxy SMPs, particularly on recovery stress enhancement. The compositions of carbon fiber and glass fiber reinforced benzoxazine-epoxy SMPs were in a range of 30 to 50vol%. The carbon fiber and glass fiber reinforced benzoxazine-epoxy shape memory polymer was compression-molded at 170oC under a pressure of 10 MPa …

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Photocatalytic Degradation Of Methylene Blue Over Polydopamine-Ag/Tio2, Kamonthip Tammarakwattana Jan 2017

Photocatalytic Degradation Of Methylene Blue Over Polydopamine-Ag/Tio2, Kamonthip Tammarakwattana

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research investigated the effect of silver and polydopamine (PDA) doping on TiO2 catalysts for the photocatalytic degradation of methylene blue in aqueous phase. Titanium dioxide was synthesized via a sol-gel method and was calcined at 400 °C for two hours. Silver was loaded onto TiO2 by an incipient wetness impregnation method. The amount of Ag was varied from 0.5%wt to 3%wt. Then polydopamine-Ag/TiO2 catalyst was prepared by an impregnation method, using dopamine as a precursor. The amounts of polydopamine were 5%wt and 10%wt. All catalysts were characterized by N2 physisorption, ICP-OES, XRD, FTIR, CO chemisorption, Photoluminescence, and UV-Visible spectrophotometry. …

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Performance Comparison Of Different Membrane Micro-Channel Reactors For Methanol Production From Biogas And Hydrogen, Khunnawat Ountaksinkul Jan 2017

Performance Comparison Of Different Membrane Micro-Channel Reactors For Methanol Production From Biogas And Hydrogen, Khunnawat Ountaksinkul

Chulalongkorn University Theses and Dissertations (Chula ETD)

In order to integrate simultaneous methanol production with biogas upgrading in a single unit, the computational fluid dynamics (CFD) models of a triple pipe tubular membrane reactor (TMR) and a planar membrane micro-structured reactor (MMR) were established via COMSOL Multiphysics 5.3a and compared their effect on reactor performance under predetermined condition. For the conceptual design of these reactors, the channel inside the reactors can be divided into three parts; biogas channel (BC), reaction channel (RC) and sweep gas channel (SC). The CO2 in biogas entering into BC is separated through CO2 selective membrane to produce methanol inside RC. Afterwards, water …

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Computational Fluid Dynamic Study Of Sorption Enhanced Steam Reforming Of Methane/Ethanol In Circulating Fluidized Bed System, Kiattikhoon Phuakpunk Jan 2017

Computational Fluid Dynamic Study Of Sorption Enhanced Steam Reforming Of Methane/Ethanol In Circulating Fluidized Bed System, Kiattikhoon Phuakpunk

Chulalongkorn University Theses and Dissertations (Chula ETD)

Two-dimensional fluid dynamic models were used to optimize and design a proper pilot-scale system for sorption enhanced steam methane reforming (SESMR) and sorption enhanced steam reforming of ethanol (SESRE) in a circulating fluidized bed reactor (CFBR) using Ni-based catalyst and dolomite as sorbent. The CFBR system was separately designed as 3 parts: including a SESMR riser, a SESRE and a regenerator. The SESMR riser could get H2 purity reached equilibrium of 98.58% in dry basis with the highest H2 flux of 0.301 kg/m2s when operating with steam to carbon ratio of 4 mol/mol, gas velocity of 6 m/s, inlet temperature …

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Synthesis Of Ptco/Tio2 Catalysts By Flame Spray Pyrolysis For Selectiive Hydrogenation Of Furfural To Furfuryl Alcohol, Kitima Kruachao Jan 2017

Synthesis Of Ptco/Tio2 Catalysts By Flame Spray Pyrolysis For Selectiive Hydrogenation Of Furfural To Furfuryl Alcohol, Kitima Kruachao

Chulalongkorn University Theses and Dissertations (Chula ETD)

The selective hydrogenation of furfural to furfuryl alcohol (FA) was carried out in a batch reactor at 50 ̊C and 20 bar H2 using Pt-Co/TiO2 with 0.5 wt%Pt and 0-0.8 wt%Co. The catalysts were characterized by X-ray diffraction (XRD), N2-physisorption, X-ray photoelectron spectroscopy (XPS), H2-temperature programmed reduction (H2-TPR), atomic absorption spectroscopy (AAS), CO-pulse chemisorption and transmission electron microscopy (TEM). Addition of Co into monometallic (I) Pt/TiO2 catalyst increased both furfural conversion and FA selectivity because it prevented anatase to rutile transformation of TiO2 and increased the interaction between metal and TiO2. However, Co adding into monometallic (F) Pt/TiO2 catalyst resulted …

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Effects Of Polyol Molecular Weights On Thermally Reversible Light Scattering Behaviors Of Benzoxazine-Urethane Copolymers, Kittipon Bunyanuwat Jan 2017

Effects Of Polyol Molecular Weights On Thermally Reversible Light Scattering Behaviors Of Benzoxazine-Urethane Copolymers, Kittipon Bunyanuwat

Chulalongkorn University Theses and Dissertations (Chula ETD)

The thermally reversible light scattering behaviors of benzoxazine-urethane copolymer was investigated in this work. Benzoxazine monomers (BA-a) were synthesized by the solventless synthesis technique from bisphenol-A, para-formaldehyde, and aniline with the molar ratio of 1:4:2, respectively. Urethane prepolymer was prepared by reacting poly(propylene glycol) (Mw = 1000, 2000, or 3000 g/mol) with toluene diisocyanate (TDI) at the molar ratio of 1:2 under a nitrogen atmosphere. The obtained urethane prepolymer (PU) was labelled as PU1K, PU2K, and PU3K with respect to the molecular weights of polyether polyol employed in the preparation step. Urethane prepolymer and benzoxazine monomers were crosslinked during the …

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Development Of High Performance Ballistic Armor From Varied Fiber Reinforced Polybenzoxazine Composites, Manunya Okhawilai Jan 2017

Development Of High Performance Ballistic Armor From Varied Fiber Reinforced Polybenzoxazine Composites, Manunya Okhawilai

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this research, a hard ballistic armor based on fiber reinforced polybenzoxazine/polyurethane (PBA/PU) composite as human body armor was developed to protect the 7.62×51 mm projectile at a velocity of 847±9.1 m/s according to National Institute of Justice at test level III. The hard armor consisted of two main panels, i.e., strike panel to destroy the tip of projectile which was made from glass fiber reinforced PBA composite and absorption panel from aramid fiber reinforced PBA/PU composite to absorb impact energy. It was found that S glass composite exhibited a greater performance than E glass composite having the same number …

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Nanocomposite Membranes Incorporated With Graphene Oxide For Co2/Ch4 Separation, Nadia Norahim Jan 2017

Nanocomposite Membranes Incorporated With Graphene Oxide For Co2/Ch4 Separation, Nadia Norahim

Chulalongkorn University Theses and Dissertations (Chula ETD)

Biogas is an alternative energy produced by anaerobic digestion of organic matter. Generally, raw biogas consists of methane (CH4), carbon dioxide (CO2), few amount of hydrogen sulfide (H2S) and traces of water vapor. Nowadays, upgrading raw biogas is required in order to achieve higher calorific value and meet fuel standard by removal of CO2. In this study, composite membranes of PEG 400/Pebax 1657 blended polymer with graphene oxide (GO) and amine functionalized graphene oxide (Fn-GO) were successfully developed for CO2/CH4 gas separation. The effects of graphene oxide, amine functionalized graphene oxide and PEG 400 additions on CO2/CH4 separation performance were …

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Synthesis Of Cu2znsns4 For Thin Film Solar Cells Prepared By Solution-Based Processes, Napaporn Khothong Jan 2017

Synthesis Of Cu2znsns4 For Thin Film Solar Cells Prepared By Solution-Based Processes, Napaporn Khothong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Copper zinc thin sulphide (Cu2ZnSnS4: CZTS) thin films were synthesized via convective deposition method at various deposit speeds based on sol-gel precursor of 2-methoxyethanol solution with metal chlorides and thiourea. The deposited films were annealed at 340 to 550ºC under N2 atmosphere to yield high quality CZTS films. The compositions, morphology, phase, and optical properties of the CZTS films were characterized by Energy dispersive X-ray analysis (EDX), Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and UV-Vis spectrophotometer, respectively. The formation films exhibited in kesterite structure and the band gap was about 1.4-1.5 eV. The CZTS films also applied …

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Characteristics And Catalytic Properties Of Agli/Sio2 Catalysts On Different Silica Supports For Oxidative Dehydrogenation Of Ethanol To Acetaldehyde, Narawich Mukda Jan 2017

Characteristics And Catalytic Properties Of Agli/Sio2 Catalysts On Different Silica Supports For Oxidative Dehydrogenation Of Ethanol To Acetaldehyde, Narawich Mukda

Chulalongkorn University Theses and Dissertations (Chula ETD)

This work focuses on investigation of the oxidative dehydrogenation and non-oxidative dehydrogenation of ethanol over AgLi/SiO2 catalysts to produce acetaldehyde by having three different types of silica support, spherical silica particle (small particle size; SPS), medium silica particle size (MPS), and large silica particle size (LPS). The spherical silica particle (SSP) was synthesized using the sol-gel method, whereas SiO2 (MPS) and SiO2 (LPS) were obtained from commercial suppliers. AgLi/SiO2 catalysts were prepared by incipient wetness co-impregnation method. The physicochemical properties of catalysts were analyzed by using several technique such as X-ray diffraction (XRD), N2-physisorption, SEM-EDX, UV-visible spectroscopy, H2-TPR. Moreover, the …

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Effects Of Titanium Dioxide Structure And Cobalt Addition On The Catalytic Properties Of Ru/Tio2 In The Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Natdanai Nanthasanti Jan 2017

Effects Of Titanium Dioxide Structure And Cobalt Addition On The Catalytic Properties Of Ru/Tio2 In The Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Natdanai Nanthasanti

Chulalongkorn University Theses and Dissertations (Chula ETD)

Furfuryl alcohol, an important intermediate for the production of many fine chemicals, is typically produced by the selective hydrogenation of lignocellulosic biomass-derived furfural using supported metal catalysts. In this research, 1.5%wt Ru catalysts supported on nanocrystalline TiO2 were prepared by incipient wetness impregnation method. The effects of crystallographic of TiO2 and Co addition in the range of 0.2-0.8 wt% on the catalytic properties of Ru/TiO2 were investigated in the selective hydrogenation of furfural to furfural alcohol at 50°C, 20 bar of H2, and 2 h reaction time. It was found that Ru supported on anatase phase TiO2 exhibited the highest …

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Dehydration Of Ethanol Over Zsm-5 Catalysts Having Different Si/Al Molar Ratios With H3po4 And Pd Modification, Nattawat Nampipat Jan 2017

Dehydration Of Ethanol Over Zsm-5 Catalysts Having Different Si/Al Molar Ratios With H3po4 And Pd Modification, Nattawat Nampipat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Dehydration of ethanol was studied over ZSM-5, HZSM-5 and modified HZSM-5 catalysts under atmospheric pressure and temperature range of 200 °C to 400 °C. ZSM-5 catalysts were prepared by hydrothermal method using tetraphopylammonium bromide, sodium silicate solution and aluminium nitrate nonahydrate. The results showed that the various Si/Al molar ratios led to affect the amount of acidity on the surface of catalysts. The ZSM-5(20) catalyst exhibited the highest ethanol conversion at 400 °C about 70.3 % due to its high acid sites and large surface area. The commercial HZSM-5 catalysts, which had molar ratio similar to ZSM-5 Si/Al 20 catalysts, …

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Ethylene Polymerization Over Cellulose-Supported Modified Methylaluminoxane/Zirconocene Catalyst, Natthadabhorn Thanarattanasap Jan 2017

Ethylene Polymerization Over Cellulose-Supported Modified Methylaluminoxane/Zirconocene Catalyst, Natthadabhorn Thanarattanasap

Chulalongkorn University Theses and Dissertations (Chula ETD)

Presently, the polyethylene has been profusely applied in the several industries, for instance manufacturing of pipe, film and plastic bags. In polyethylene production, there are two catalysts which are used in production, including Ziegler-Natta catalyst and metallocene catalyst. The metallocene catalyst is immobilized by support and activated by cocatalyst. For the support of metallocene catalysts, both of inorganic and organic supports are applied and in this research study, cellulose which is organic support for metallocene catalyst, was used. Since, cellulose is extensively used biopolymer representing a great deal of total annual biomass production. Due to environmental issues, natural materials have …

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Effects Of Pbs Quantum Dot Doped Tio2 Nanotubes As Electron Transporting Layer On The Efficiency Of Perovskite Solar Cells, Natthapat Rattanawichai Jan 2017

Effects Of Pbs Quantum Dot Doped Tio2 Nanotubes As Electron Transporting Layer On The Efficiency Of Perovskite Solar Cells, Natthapat Rattanawichai

Chulalongkorn University Theses and Dissertations (Chula ETD)

TiO2 nanotubes (TNTs) are used as an excellent electron transporting layer for high efficiency perovskite solar cells. In this work, TNTs were synthesized via hydrothermal process from different particle sizes of TiO2 nanoparticle precursors as follows: 5 nm, 25 nm, and 50 nm. The highest surface area of 312.39 m2/g of TNTs was obtained from TiO2 precursor with particle size of 25 nm and was used to dope with lead sulfide quantum dots (PbS QDs). Due to a large band gap and poor conductivity of TNTs which limits the efficiency to transport electrons in the perovskite solar cell, PbS QDs …

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Hydrogen Production From Biogas By The Combined Process Of Chemical Looping Water Splitting And Sorption Enhanced Reforming Process: Process Analysis And Design, Natthaporn Saithong Jan 2017

Hydrogen Production From Biogas By The Combined Process Of Chemical Looping Water Splitting And Sorption Enhanced Reforming Process: Process Analysis And Design, Natthaporn Saithong

Chulalongkorn University Theses and Dissertations (Chula ETD)

The integrated sorption-enhanced chemical looping reforming and water splitting (SECLR-WS) process was proposed for hydrogen (H2­­) production from biogas using iron oxide as the oxygen carrier and calcium oxide (CaO) as a carbon dioxide (CO2) adsorbent. The simulation of the SECLR-WS process was based on a thermodynamic approach and was performed using an Aspen Plus simulator. The sensitivity results showed that the H2 yield (mole of H2/mole of CH4), H2 purity in the fuel reactor (FR), and CH4 conversion could be improved by increasing the steam feed to the FR to CH4 (SFR/CH4) and CaO to CH4 (CaO/CH4) molar ratios. …

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Improving Fouling Resistance Of Thin Film Composite Membranes By Addition Of Tio2, Palach Kedchaikulrat Jan 2017

Improving Fouling Resistance Of Thin Film Composite Membranes By Addition Of Tio2, Palach Kedchaikulrat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Polyamide thin film nanocomposite (TFN) membranes with the addition of titanium dioxide (TiO2) nanoparticles (NPs) were synthesized via an interfacial polymerization (IP) on polyacrylonitrile (PAN) support. Also, the TFC membranes with addition of individual components in the TiO2 colloidal solution, ethanol, TiO2 NPs and nitric acid, were individually studied. The performances of the fabricated membranes were evaluated in terms of NaCl salt rejection, water permeability and anti-fouling capability. Membranes characterizations were conducted to observe various characteristics of membranes such as morphology, surface roughness, surface chemistry and hydrophilicity. The results revealed that the addition of TiO2 colloidal solution in aqueous amine …

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