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Study Of The Cracking Reaction In Ethylene Reactant, Atchariya Anantapanyasut
Study Of The Cracking Reaction In Ethylene Reactant, Atchariya Anantapanyasut
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this thesis, the main objectives were to study the cracking of ethylene, comparing between thermal cracking and catalytic cracking reactions. The ethylene and nitrogen which atomic ratio 1:1 were used as reactant feed on Al2O3, zeolite-Y and silica-supported tungsten catalysts at 723 K and 25 atm. The inert SiO2 was used to represent the thermal cracking. The catalysts were characterized by NH3-TPD. The product distribution was clearly different between the thermal cracking and catalytic cracking. Thermal cracking produced the olefin products while catalytic cracking produced paraffin products.
Effect Of Aluminosilicate Type In The Physically Mixed Support On Wox/Sio2-Aluminosilicate Catalyst For Metathesis Of Ethylene And 2-Butene, Kittayanee Suwanthorn
Effect Of Aluminosilicate Type In The Physically Mixed Support On Wox/Sio2-Aluminosilicate Catalyst For Metathesis Of Ethylene And 2-Butene, Kittayanee Suwanthorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Silica supported tungsten catalysts were physically mixed with different acidic material types (similar particle size ≈ 53-106 µm) as an extra support and compared with the case as bi-support. All catalysts were tested in the metathesis reaction of ethylene and trans-2-butene to propylene and characterized by XRD, NH3-TPD, FTIR-pyridine, UV-vis, Raman, SEM-EDX, TPR and TPO, systematically comparing with reference catalyst, which were physically mixed with SiO2 as the extra support. Adding acidic material resulted in an increased total acidity of the catalysts. Moreover, it could improve the WOx dispersion on the surface and increase the active site precursors. These led …
Determination Of Interconnection Rate For Thailand's Mobile Telecommunication Industry, Thanoot Yamajinda
Determination Of Interconnection Rate For Thailand's Mobile Telecommunication Industry, Thanoot Yamajinda
Chulalongkorn University Theses and Dissertations (Chula ETD)
Relatively high and unbalanced level of termination rates can cause conflict between operators, and create burden for the consumers. It is within the regulator’s responsibility to step in and intervene with the situation. This thesis aims to find an appropriate solution to determine the mobile interconnection rate of Thailand. The calculation utilized a bottom-up cost model developed with modern efficient operation assumption. Three possible costing approaches, i.e. Long Run Incremental Cost (LRIC), Long Run Average Incremental Cost (LRAIC), and Long Run Average Incremental Cost Plus (LRAIC+) were studied. LRAIC+ was chosen as the standard basis for the calculation framework to …
Production Process Improvement For The Marinated Pork Factory, Patcharaporn Musuwan
Production Process Improvement For The Marinated Pork Factory, Patcharaporn Musuwan
Chulalongkorn University Theses and Dissertations (Chula ETD)
A marinated pork manufacturing company of Thailand has been wanting to expand its sales channels by moving its marinated pork products from solely lower market sales channel into Thailand’s hypermarket in order to attract more customer target groups. To do so, the company needed to adapt all Good Manufacturing Practices (GMP) standards in its factories and become GMP certified by Thailand’s Food and Drug Administration (FDA) to satisfy the requirement of most popular hyper markets in Thailand. The aim of this thesis is to implement solutions that would help this marinated pork company achieve GMP standards and improve its production …
Study And Analysis Of Electrolyte Imbalance In A Vanadium Redox Flow Battery, Kittima Ngamsai
Study And Analysis Of Electrolyte Imbalance In A Vanadium Redox Flow Battery, Kittima Ngamsai
Chulalongkorn University Theses and Dissertations (Chula ETD)
Electrolyte imbalance which is an important problem for long-term operation of a vanadium redox flow battery (VRB) is studied and analyzed in this research. A cause of the electrolyte imbalance is firstly studied. The air oxidation of vanadium (V(II)) which is the side reaction in an electrolyte reservoir is investigated. The effects of the ratio of the electrolyte volume to air-electrolyte solution interface area and the ingredients of electrolyte solution on the rate of air oxidation of V(II) are investigated. The results show that the high ratio of the electrolyte volume to air-electrolyte solution interface area can retard the oxidation …
Laboratory Investigation And Numerical Modelling Of Track Foundation For High-Speed Railway Construction On Bangkok Soft Soil, Phitsanu Pholkainuwatra
Laboratory Investigation And Numerical Modelling Of Track Foundation For High-Speed Railway Construction On Bangkok Soft Soil, Phitsanu Pholkainuwatra
Chulalongkorn University Theses and Dissertations (Chula ETD)
The government of Thailand has recently decided to launch a high-speed railway project to promote regional economy and improve the logistics of trade to connect with other countries in Southeast Asia community. Raising a complication regarding the load transfers will certainly induce many problems to the railway system. Moreover, the constructions of railway substructures in the past often involve the low quality of materials especially in the Central Plain of Thailand. Therefore, it is necessary to determine the sources of construction materials for railway substructure materials. This study consists of two main objectives. The first objective is to investigate the …
Effect Of Citric Acid On Hydrodesulfurization Activity Of Dibenzothiophene And 4,6 Dimethyldibenzothiophene Over Como Catalyst On Al2o3-Zro2 Support, Pawinee Sintarako
Effect Of Citric Acid On Hydrodesulfurization Activity Of Dibenzothiophene And 4,6 Dimethyldibenzothiophene Over Como Catalyst On Al2o3-Zro2 Support, Pawinee Sintarako
Chulalongkorn University Theses and Dissertations (Chula ETD)
The effect of citric acid on the HDS activity of DBT and 4,6 DMDBT on CoMo/γ-Al2O3-ZrO2 catalysts has been investigated. It has been found that the CoMo/γ-Al2O3-ZrO2 physically mixed with 10wt.% of ZrO2 shows the highest HDS conversion of DBT in the presence of pyridine. The addition of ZrO2 as a secondary support obviously suppresses the influence of pyridine on HDS activity of DBT over CoMo/γ-Al2O3 based catalyst. The synergistic benefits of ZrO2 and citric acid on HDS activity of DBT and 4,6 DMDBT over CoMo/γ-Al2O3 catalyst are not found. The modification of CoMo/γ-Al2O3 catalyst by citric acid can inhibit …
Modification Of W/Sio₂ Catalysts By Second Metal For Metathesis Of Ethylene And 2-Butene, Narongrat Poovarawan
Modification Of W/Sio₂ Catalysts By Second Metal For Metathesis Of Ethylene And 2-Butene, Narongrat Poovarawan
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this thesis, the main goals were to study the effect of the dispersion of the tungsten active phase and the modification of WO3/SiO2 catalyst by a second metal for metathesis reaction of the mixture of cis/trans-2-butene and ethylene. The silica supported tungsten catalyst was used as the base catalyst and lanthanum, cerium, yttrium were used as the second metal in this study. It was found that the dispersion of the tungsten active phase would affect the catalytic performance of the WO3/SiO2 catalyst, when the mixture of cis/tran-2-butene was use as feed.The second metal was used to midify the dispersion …
Understand Management Of Public-Private Partnership In A Secondary Private Hospital Providing Services To Citizens Registered Under Different Insurance Schemes, Rani Sachadev
Chulalongkorn University Theses and Dissertations (Chula ETD)
In light of the recent public-private partnership law reenacment in various industries, it seems that the healthcare's public insurances would largely benefit from increase participation of the private sector but since there has not been any published framework on management of public-private partnership in public health insurance, this study has been undertaken to shine a light on financial and medical care delivery in a secondary private hospital. This study was conducted in a secondary private hospital located in Bangkok providing UC, SSS and for-profit medical care to citizens. This is a study aimed to understand the management strategies regarding finance …
Innovative Wind Energy Micro-Generation System: A Case Study For Rooftop Turbine Ventilator, Ponnson Kaewtip
Innovative Wind Energy Micro-Generation System: A Case Study For Rooftop Turbine Ventilator, Ponnson Kaewtip
Chulalongkorn University Theses and Dissertations (Chula ETD)
Wind micro-generation has become an approach for new age wind energy. Whereas, the conventional and centralized wind farms only work well with wind speed beyond 8 m/s, these are only capable when locating within the remote wind zones. To develop wind-power generation that can generate electricity right at point of uses, will reduce transmission and distribution losses and minimize investment costs. This study uses innovative approach to develop Vertical Axis Wind Turbine (VAWT), through redesign and modification an internal frame of standard rooftop ventilators, transforming into Rooftop Turbine Ventilator (RTV) micro-generation system, based on VAWT. In order to cope with …
Effects Of Acemannan Deacetylation On Biological Activity Of Gingival Fibroblast, Jaroenporn Chokboribal
Effects Of Acemannan Deacetylation On Biological Activity Of Gingival Fibroblast, Jaroenporn Chokboribal
Chulalongkorn University Theses and Dissertations (Chula ETD)
Acemannan extracted from Aloe vera gel is unique in the presence of acetylated mannose residues and was reported to accelerate mice buccal wound healing. In order to assert structural and biological roles of mannose acetyl groups, high-molecular-mass DeAcAM of various DDAs were prepared by alkaline hydrolysis at 80°C for 5 min using varied concentrations of NaOH. All of the DeAcAMs are not cytotoxic to HGFs and their effects on cell proliferation and VEFG and type I collagen expressions were further investigated. In general, bioactivities of the DeAcAMs were lost to some extents upon the removal of the mannose acetyl groups …
Suitable Catalyst Bed Arrangement Of Silica-Based Supported Tungstenand Hydrotalcite Catalysts For Propylene Production From 1-Butene, Sirada Sripinun
Suitable Catalyst Bed Arrangement Of Silica-Based Supported Tungstenand Hydrotalcite Catalysts For Propylene Production From 1-Butene, Sirada Sripinun
Chulalongkorn University Theses and Dissertations (Chula ETD)
The research studied the design of suitable catalyst beds of hydrotalcite and the modified silica supported tungsten for propylene production from 1-butene. The study started with performing reactions at various values of gas hourly space velocity, feed composition and temperature. Then the reaction rate expressions for each catalyst were determined. It was found that the models could predict well the experimental results. The models were further used to simulate the reaction performance of reactors packed with different catalyst beds. The performance was shown in terms of molar flow rate of propylene and yield of propylene. The performance of the catalyst …
Simulation Of Temperature Distribution In A Thermal Drying Oven Based On Three Dimensional Cfd Model, Patsarawan Lipikanjanakul
Simulation Of Temperature Distribution In A Thermal Drying Oven Based On Three Dimensional Cfd Model, Patsarawan Lipikanjanakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research presents a study of air velocity in a thermal drying oven in drying zone. To reduce a heat loss, a mass flow rates are decreased from 100% to 10%. The effect of the mass flow rate can be divided into three parts; air velocity, air temperature, and concentration of solvent. A three-dimensional CFD with a non-isothermal model and a transport of diluted species were simulated by using COMSOL. For ensuring the result, all results are compared with MATLAB program by focusing in two-direction (length-height). The parameters of air velocity that uses in this program is the results of …
Propane Dehydrogenation To Olefins Via Modified Pt-Based/Γ-Al2o3, Napat Hataivichian
Propane Dehydrogenation To Olefins Via Modified Pt-Based/Γ-Al2o3, Napat Hataivichian
Chulalongkorn University Theses and Dissertations (Chula ETD)
The effect of transition metal(X) added on Pt/Al2O3 catalyst was studied in propane dehydrogenation reaction at 500oC. The metal contents were fixed at 0.3%wt for Pt, 4%wt for X. It was found that the transition metal had an effect upon reducibility of platinum due to its interaction with X-containing structure, resulting in the presence of Pt metal was decreased and lower initial conversions are observed. However, the final conversions are not decreased, thus the bimetallic catalysts had a better stability because the transition metal sites attracted propylene from Pt sites, so there is no propylene remain adsorbed on Pt site, …
Metathesis Of Ethylene And 2-Butene For Propylene Production Using Naoh Modified Wo3/Sio2 Catalysts, Surasa Maksasithorn
Metathesis Of Ethylene And 2-Butene For Propylene Production Using Naoh Modified Wo3/Sio2 Catalysts, Surasa Maksasithorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
WO3-based catalyst is one of the most successful catalysts for producing propylene via olefin metathesis. Traditionally, it is prepared by an incipient wetness method. This suffer from severe limitations such as inhomogeneity of the WO3 deposit, alteration of the texture (pore plugging, etc.) and genesis of inactive species (WO3 crystals), resulting in low catalytic performance. The present study exploits innovative preparation methods for more efficient WO3-based catalysts by using two methods of one step preparation including non-hydrolytic sol-gel route and aerosol-assisted sol-gel process. These methods offer good control on the final catalyst composition, provide mixed oxides with excellent textures, feature …
Outsourcing Management Of Engineering Work In Petroleum Exploration And Production, Panunee Thongprasom
Outsourcing Management Of Engineering Work In Petroleum Exploration And Production, Panunee Thongprasom
Chulalongkorn University Theses and Dissertations (Chula ETD)
Since there is no official outsourcing management system in the studied Petroleum Exploration and Production company, many outsourcing projects under the studied company have been facing with a lot of schedule delays. Therefore, the purpose of this research is to find an appropriate and efficient outsourcing management system which consists of workflow and procedure including supporting tools and techniques for using with outsourcing engineering work in the studied company to minimize the delays. The approach is to review outsourcing management practices and recommended tools from literatures and gather information from the studied company’s outsourcing experiences including best practices to develop …
Effect Of Jagged-1 And Delta-Like1 On The Proliferation And Osteogenic Differentiation Of Primary Deciduous Pulp Cells, Karnnapas Peetiakarawach
Effect Of Jagged-1 And Delta-Like1 On The Proliferation And Osteogenic Differentiation Of Primary Deciduous Pulp Cells, Karnnapas Peetiakarawach
Chulalongkorn University Theses and Dissertations (Chula ETD)
Objectives: The purpose of the present study was to investigate the influence of Notch ligands, Jagged-1 and Delta-like1, on the proliferation and osteogenic differentiation of primary deciduous pulp cells in vitro. Methods: Jagged-1 and Delta-like1 ligands were immobilized to the tissue culture surface using indirect affinity immobilization technique. Cell proliferation was determined by a MTT assay and the mRNA expression levels of apoptosis related-genes. The osteogenic differentiation was determined by the ALP activity assay, the mineralization assay, and the mRNA expression levels of osteogenic genes. Statistical analyses were performed using Kruskal-Wallis H followed by Mann-Whitney U. Results: Cell proliferation was …
Metathesis Reaction Of Ethylene And 2-Butene On Molybdenum-Based Catalysts, Benjamas Netiworaruksa
Metathesis Reaction Of Ethylene And 2-Butene On Molybdenum-Based Catalysts, Benjamas Netiworaruksa
Chulalongkorn University Theses and Dissertations (Chula ETD)
This dissertation studies and develops the supported molybdenum catalyst for metathesis reaction of ethylene and 2-butene to produce propylene. It was found that the major factor affecting the catalytic performance for metathesis reaction is the catalyst support. From this study, it was firstly revealed that the suitable support for molybdenum-based catalyst is the mixed support of alumina and zeolite. The catalyst containing alumina support prepared from aluminium nitrate physically mixed with HBeta support could provide high selectivity of propylene. The optimum ratio of the composite support of alumina and zeolite was 3:1. However, the most optimum support obtaining propylene selectivity …
Effect Of Additives In Lubricant On Cobalt-Iron Alloy Lapping, Wiraya Anamnart
Effect Of Additives In Lubricant On Cobalt-Iron Alloy Lapping, Wiraya Anamnart
Chulalongkorn University Theses and Dissertations (Chula ETD)
To maintain this flying height of read-write head (called slider) at 12 nm across the disk, read and writer elements will be lapped to meet designed surface roughness, surface topography, as well as magnetic property. The writer element was made from cobalt-iron alloy (CoFe). Final lapping process of sliders uses lubricant to control surface morphology and to avoid corrosion. The aim of this study was to determine the effect of additives on corrosion protection of CoFe. The corrosion was studied by potentiostat technique and atomic force microscopy (AFM). Water content was determined by Karl Fischer method. Thin film passivation was …
The Effect Of N-Trans-P-Coumaroyl Tyramine On Indomethacin-/Diclofenac-Mediated-Cytotoxicity In Breast Cancer Cells., Angkana Wongsakul
The Effect Of N-Trans-P-Coumaroyl Tyramine On Indomethacin-/Diclofenac-Mediated-Cytotoxicity In Breast Cancer Cells., Angkana Wongsakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
Indomethacin (INDO) and diclofenac (DIC) are non-steroidal anti-inflammatory (NSAIDs) have been reported their anticancer potential. Their cytotoxicity could be increased when combining with certain natural compounds such as piperine in Piper plants. N-trans-p-coumaroyltyramine (TCT) (a coumaric acid derivative) was also found at significant amount in these plants and other commonly used in traditional medicine. This study determined the potentiative effect of TCT on NSAIDs (INDO and DIC) induced cytotoxicity in MCF-7 breast cancer cells, and the underlying mechanisms. Combination of TCT with either NSAIDs or various ER stressors at their non-cytotoxic concentrations were able to reduce cell viability in MCF-7 …
Synthesis And Characterization Of Poly(Urethane-Imide)/Poss Nanocomposite, Supanan Patthamasang
Synthesis And Characterization Of Poly(Urethane-Imide)/Poss Nanocomposite, Supanan Patthamasang
Chulalongkorn University Theses and Dissertations (Chula ETD)
A novel type of poly(urethane-imide) (PUI) was prepared by blending the isocyanate terminated polyurethane containing dihydroxy-POSS prepolymer (PU/POSS) and anhydride-terminated polyimide (PI) with various chain lengths of PU/POSS prepolymer and various molecular weights of PI. The effect of chain length of PU prepolymer and molecular weight of PI on the properties of PUI/POSS films was examined. From the results, we found the best condition for synthesis of the PUI/POSS hybrid films is to use the PI prepared via 1 step method with MW of 80,000 and that can prepared the transparent films, follwed by casting films and heat treatment at …