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2020

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The Promotion Of French Language And Culture By Alliance Française In Bangkok, Thailand, Shu-Chin Huang Jan 2020

The Promotion Of French Language And Culture By Alliance Française In Bangkok, Thailand, Shu-Chin Huang

Chulalongkorn University Theses and Dissertations (Chula ETD)

The French language plays an important role in international society. It is widely used in commerce, diplomatic and academic fields, and is generally recognised as a representative of high culture. However, the language is facing a fast decline in Southeast Asia due to globalisation, which has expanded the role of English very rapidly all over the world. To solve the problem of the decrease in the role of French in the world, Alliance Française was established to disseminate the knowledge of French language and culture around the world. This study aims to analyse the strategies used by Alliance Française to …

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The Strategy Of Using Foreign Idols To Make K-Pop Entertainment Companies Success In Global Market: The Case Study Of Thai K-Pop Idols, Sida Smarnmit Jan 2020

The Strategy Of Using Foreign Idols To Make K-Pop Entertainment Companies Success In Global Market: The Case Study Of Thai K-Pop Idols, Sida Smarnmit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study explores the strategy of using foreign idols to makes K-POP entertainment companies successful in the global market. This research is qualitative research and analysis of people's perspectives from the interview of three groups of people and related research documents. In addition, this research used the generalized double diamond model by Chang Moon to analyze K-POP entertainment company's strategies. The results of study on the strategy of using foreign idols to make K-POP entertainment companies success in global market were (1) K-pop idol production system, appearance, and characteristic. (2) Thai K-pop idol production strategy and Social Network Strategy (3) …

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City-Wide Greenhouse Gas Mitigation Options To Support Global Climate Goals: Case Studies Of Bangkok, Chiang Mai, And Rayong, Thailand, Sittisak Sugsaisakon Jan 2020

City-Wide Greenhouse Gas Mitigation Options To Support Global Climate Goals: Case Studies Of Bangkok, Chiang Mai, And Rayong, Thailand, Sittisak Sugsaisakon

Chulalongkorn University Theses and Dissertations (Chula ETD)

The action of city on climate mitigation becomes a crucial role. The aims of this study were to quantify greenhouse gases (GHGs) emission, identify feasibility of mitigation options in selected provinces, and to evaluate the performance of local capacity to support Thailand's Nationally Determined Contributed (NDC) and 1.5oC limit pathway. Three provinces, including Bangkok, Chiang Mai and Rayong of Thailand were selected as case studies. The results revealed that stationary energy was the greatest contribution to the city's GHGs emissions in all case studies. Transportation was the second largest emitter in Bangkok and Chiang Mai, whereas IPPU was the second …

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Leaching Potential Assessment Of Atrazine And Nitrate In Sugarcane Field, Suphan Buri Province, Sorranat Ratchawang Jan 2020

Leaching Potential Assessment Of Atrazine And Nitrate In Sugarcane Field, Suphan Buri Province, Sorranat Ratchawang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Atrazine is widely used as a herbicide to control annual broadleaf in agricultural area such as rice and sugarcane. It is considered as one of endocrine disrupting chemicals. Atrazine also affects liver, the central nervous system, immune system and cardiovascular function. The study area is sugarcane field in U-thong and Song Phi Nong district, Suphan Buri province. In this area, soil and groundwater samples were collected at eight different points distributed over the sugarcane area with different soil types. Batch adsorption experiment was carried out to evaluate the proper adsorption isotherm of each soil. Additionally, groundwater samples were analyzed for …

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Development Of Tod Readiness Index And Its Application To Transit Station In Bangkok, Srisamrit Supaprasert Jan 2020

Development Of Tod Readiness Index And Its Application To Transit Station In Bangkok, Srisamrit Supaprasert

Chulalongkorn University Theses and Dissertations (Chula ETD)

Studies on the Transit-Oriented Development (TOD) for Bangkok are found sparingly. The TOD concept is a supportive development for the rapidly changing city in order to reduce urban transport problems while encouraging people to shift transport modes to use public transportation instead of private cars. This study discusses the context of TOD in the density, the design, and the diversity of land use around transit stations among successful stations in many countries. There were 18 station areas in Bangkok which, by using the TOD Readiness score, the assessment of the stations implies that the higher scoring transit stations are more …

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Effect Of 2-(4"-Hydroxybenzyl)-5-2"-Dihydroxy-3- Methoxystilbene On Apoptosis And Autophagic Cell Death Of Lung Cancer Cells, Sucharat Tungsukruthai Jan 2020

Effect Of 2-(4"-Hydroxybenzyl)-5-2"-Dihydroxy-3- Methoxystilbene On Apoptosis And Autophagic Cell Death Of Lung Cancer Cells, Sucharat Tungsukruthai

Chulalongkorn University Theses and Dissertations (Chula ETD)

The shifting of autophagy, a catabolic process for cell survival, toward death could be a potential mode of anti-cancer drug action. In addition, autophagic cell death (ACD) is an alternative death mechanism in resistant malignant cancer cells. This study, we demonstrated how PE5, a stilbene compound, exhibits potent ACD-promoting activity and apoptosis in lung cancer cells that may offer an opportunity for novel cancer treatment. It was found that PE5 exerted a higher toxic effect toward cancer cells compared with its effect on normal cells. Interestingly, the cell death caused by PE5 was found to be concomitant with dramatic autophagy …

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Detection Of Arsenite-Oxidizing Bacteria In Groundwater From A Gold Mine Under Different Geochemical Environments, Supeerapat Kraidech Jan 2020

Detection Of Arsenite-Oxidizing Bacteria In Groundwater From A Gold Mine Under Different Geochemical Environments, Supeerapat Kraidech

Chulalongkorn University Theses and Dissertations (Chula ETD)

Millions of people around the world potentially expose to arsenic (As) contaminated groundwater. Besides, the dominant form of As in groundwater is arsenite (As+3) and is more toxic than arsenate (As+5). This study integrated the microbial investigation, geochemical modeling, and multivariate statistical analysis to investigate the arsenite-oxidizing bacteria community from As-contaminated groundwater and its environmental influencing factors in order to understand and further develop the in-situ arsenic bioremediation technology. Microbial investigation was focusing on the detection and identification of native arsenite-oxidizing bacterial community using PCR-DGGE, cloning and sequencing of arsenite oxidase (aoxB) gene amplicons. Nine groundwater samples were collected from …

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Characterization Of Carbon Storage Regulator A (Csra) Homolog As A Global Gene Regulator In Leptospira Spp., Theerapat Phoka Jan 2020

Characterization Of Carbon Storage Regulator A (Csra) Homolog As A Global Gene Regulator In Leptospira Spp., Theerapat Phoka

Chulalongkorn University Theses and Dissertations (Chula ETD)

Leptospira spp. consist of non-pathogenic and pathogenic species. The bacteria can survive in diverse environments and therefore need mechanisms of rapid adaptation to environmental changes. However, molecular mechanisms of stress response in Leptospira are not fully understood. Carbon Storage Regulator A (CsrA) is a well-characterized, conserved, post-transcriptional global regulator that plays a critical role in response to environmental changes in many bacteria. CsrA has been reported to regulate several pathways such as glycogen metabolism, motility, biofilm formation, and virulence-associated genes. Based on available genomics data of Leptospira spp., we found putative csrA homolog, approximately 50% similarity with csrA of E. …

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Comparative Evaluation Of Mineral Trioxide Aggregate And Acemannam For Partial Pulpotomy In Permanent Teeth With Incomplete Root Formation, Thuy Tien Vu Jan 2020

Comparative Evaluation Of Mineral Trioxide Aggregate And Acemannam For Partial Pulpotomy In Permanent Teeth With Incomplete Root Formation, Thuy Tien Vu

Chulalongkorn University Theses and Dissertations (Chula ETD)

Mineral trioxide aggregate (MTA), the standard pulp capping material, has disadvantages, including long setting time and high cost. Along this line, acemannan, a polysaccharide extracted from aloe vera, would be a promising biomaterial for vital pulp therapy as it is shown to induce mineralized bridge formation in animal and clinical studies. In this study, the impact of MTA and acemannan sponges on partial pulpotomized permanent teeth has been evaluated. For the research design, fifty immature permanent teeth with caries or accident-induced pulp exposure were collected and assessed. After partial pulpotomy, the teeth were randomly allocated into the treatment group using …

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The Differential Dendritic Cell Properties In Response To Candida Albicans And Non-Albican Candida Β-Glucan, Truc Thi Huong Dinh Jan 2020

The Differential Dendritic Cell Properties In Response To Candida Albicans And Non-Albican Candida Β-Glucan, Truc Thi Huong Dinh

Chulalongkorn University Theses and Dissertations (Chula ETD)

Increased mortality and antifungal drug resistance of non-albicans Candidiasis patients have become an alarming in health problems nowadays, whereas profound knowledge of their pathogenesis mechanisms is still limited. The immune responses of innate and adaptive immunity play a crucial role in protecting from Candida infections. Dendritic cells (DCs) are the most notable because of their roles in bridging an innate immunity and specific adaptive immunity to eliminate fungal invasion. It is little known about DC functions in non-albicans Candida (NACs) infections. Besides, there is less study on evaluating the DC properties upon the interaction between DCs and NACs-derived ß-glucans. Therefore, …

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Servitization Model For Chemical Industry In Thailand, Tanyaporn Kanignant Jan 2020

Servitization Model For Chemical Industry In Thailand, Tanyaporn Kanignant

Chulalongkorn University Theses and Dissertations (Chula ETD)

Chemical industry traditionally produces and sells tangible goods in large volume and high price cometition. Recently, firms in chemical industry provide additional services to their customers. Several manufacturers change from tangible product suppliers to both product and service providers. This movement is called servitization (Vandermerwe & Rada, 1988). Chemical servitization levels can be classified into 4 categories which are product only, service added to the product, service differential the product and service is the product (Thoben, Eschenbacher, & Jagdev, 2001). The objectives of this paper are to construct servitization framework for chemical suppliers to shift to product service integration and …

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The Effects Of Project-Based Drama Approach Via Blended Learning Environment On Thai Efl Undergraduated Student's Speaking Skills, Tunyaphoom Phu-Ngamthong Jan 2020

The Effects Of Project-Based Drama Approach Via Blended Learning Environment On Thai Efl Undergraduated Student's Speaking Skills, Tunyaphoom Phu-Ngamthong

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objectives of this study were 1) to examine the effectiveness of project-based drama approach via blended learning environment on English speaking skills, and 2) to investigate the students’ opinions towards project-based drama approach via blended learning environment on English speaking skills.The framework was derived from the combination of three models; Teaching English through Drama for Oral Skills Model, the Project-Based Learning framework, and the Blended Learning Model. The study was conducted face-to-face and online for 14 consecutive weeks in the second semester of Academic Year of 2020 at Ubon Ratchathani Rajabhat University. The participants were 51 third-year students who …

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Sustainable Business Development Through Sufficiency Economy Practice : A Case Study Of Thai Listed Companies, Veerawin Korphaibool Jan 2020

Sustainable Business Development Through Sufficiency Economy Practice : A Case Study Of Thai Listed Companies, Veerawin Korphaibool

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of the research is to determine the sufficiency economy philosophy (SEP) performance through annual and sustainable development reports and simplify the outcomes by representing through a scoring system. Each of the SEP elements was aligned with each GRI sub-topic to generate a SEP scoring system. Then, the results from the scoring system were verified by testing the relationship between SEP performance and firm-specific risk of 34 Thai listed companies from 2013 to 2018 via panel data analysis. The global reporting initiative (GRI) standards were used as the fundamental scoring system as it's widely used and accepted in academic …

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Parasite: A Reflection On Social And Economic Disparities In South Korea, Wilasinee Nichasuk Jan 2020

Parasite: A Reflection On Social And Economic Disparities In South Korea, Wilasinee Nichasuk

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this research is to analyze a reflection of social problems in "Parasite" film. The study is a qualitative research that uses semiology theory to analyze the social problems in the film through elements such as visual sign, scene, dialogue etc. The results of these analyses show that "Parasite" film reflects the social problems in South Korea through a visual sign, scene, dialogue such as disparity social class problems. These problems that occur in South Korea are partly due to a result of the rapid change in South Korea society and adoption of the capitalist system to develop …

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Supply Chain Collaboration For Sustainability In Thailand's Dairy Industry, Virayos Vajirabhoga Jan 2020

Supply Chain Collaboration For Sustainability In Thailand's Dairy Industry, Virayos Vajirabhoga

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study gathered potential 95 variables from a literature review. Through the process of expert review, these were refined into 49 critical variables. Moreover, pilot study, with participation from co-operatives and farmers, aims to develop conceptual frameworks in six areas: performance and commitment, internal and external collaboration, measurement and evaluation, joint operation, sharing and innovation, and negotiation. Furthermore, 26 factors were identified clearly by exploratory factory analysis. The main study was conducted via a paper-based questionnaire with 1,224 respondents nationwide. The proposed 11 hypotheses attempted to identify the structural relationships among the constructs in the model. The result confirmed the …

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Neutrophil Extracellular Traps (Nets) Formation Of Fcgr2b Deficient Mice In Lupus Mouse Model With Ischemic Reperfusion Injury, Wilasinee Saisorn Jan 2020

Neutrophil Extracellular Traps (Nets) Formation Of Fcgr2b Deficient Mice In Lupus Mouse Model With Ischemic Reperfusion Injury, Wilasinee Saisorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Acute kidney injury (AKI) caused by renal ischemic reperfusion (I/R) is the most prevalent cause of morbidity and mortality in patients. Neutrophil extracellular traps (NETs) are important for the progression of lupus nephritis after renal I/R injury. Because neutrophils are the first immune cell that respond to tissue damage, neutrophils might be an important cell that determines renal I/R injury. Additionally, NET components, including cell-free DNA, histone, nucleosome, and cytoplasmic protein compartment release the auto-antigens that accelerate lupus disease activity. Therefore, this project aimed to compare NETs formation in several internal organs following renal I/R injury in Fcgr2b deficient (Fcgr2b-/-) …

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Avoidance Of The English Passive Construction By L1 Chinese Learners, Yang Wang Jan 2020

Avoidance Of The English Passive Construction By L1 Chinese Learners, Yang Wang

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research investigated avoidance behaviour as one of the strategies L2 learners may resort to because of L1-L2 differences, or the non-existence of L2 structures for L1 learners (Schachter 1974; Dagut and Laufer 1985). Schachter (1974) proposed the Avoidance Behaviour Hypothesis, whereby L2 learners were likely to avoid using some L2 structures due to the aforementioned difficulties in L2 acquisition. Later researchers, i.e. Dagut and Laufer (1985), and Laufer and Eliasson (1993), claimed that L1-L2 differences tended to play a role, or at least would be the 'best predictor' (1993, p46) of avoidance. However, recent researchers, i.e. Thiamtawan and Pongpairoj …

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Assessments Of Hydraulic Responses To Climate Variability Of Dominant Trees In Successional Forests In Khao Yai National Park For Environmental Management, Weerapong Unawong Jan 2020

Assessments Of Hydraulic Responses To Climate Variability Of Dominant Trees In Successional Forests In Khao Yai National Park For Environmental Management, Weerapong Unawong

Chulalongkorn University Theses and Dissertations (Chula ETD)

In Southeast Asia, tropical forests have been increasingly threatened by human disturbances and climate change-induced water stress. However, uncertainty remains as to how these forests would respond to environmental changes under water deficit conditions. Here, we conducted a study of seasonal variation in leaf water status and hydraulic properties of dominant tree species across forest successional stages in Khao Yai National Park, Thailand. Specifically, we measured midday leaf water potential (Ψmd) during the wet and dry season, and assessed branch xylem vulnerability at which 50% is lost (P50). The associations between P50 and maximum xylem hydraulic conductivity (Ksmax) and maximum …

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Innovative Zero-Waste System For Building Wastewater Recycling And Food Waste Management, Thammananya Sakcharoen Jan 2020

Innovative Zero-Waste System For Building Wastewater Recycling And Food Waste Management, Thammananya Sakcharoen

Chulalongkorn University Theses and Dissertations (Chula ETD)

Urbanization leads to concerns about environmental impacts due to the increasing food waste and wastewater generation. The study aims to develop an innovative zero-waste system for food waste and wastewater management in the building using the combination of a single-stage anaerobic digester and the Moving Bed Biofilm Reaction-Membrane Bioreactor (MBBR-MBR). The comprehensive analysis for innovative zero-waste system development is conducted including (1) survey and interview the target market group (universities) to determine the factors affecting the intention to use the zero-waste system ; (2) develop a zero-waste system prototype, and test operation for measuring the performances ; (3) evaluate the …

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Over-Expression Of Mir-223 Induces M2 Macrophage Through Glycolysis Alteration And Attenuates Lipopolysaccharide-Induced Sepsis Mouse Model, A Proposal Sepsis Cell-Based Therapy, Dang Phi Cong Jan 2020

Over-Expression Of Mir-223 Induces M2 Macrophage Through Glycolysis Alteration And Attenuates Lipopolysaccharide-Induced Sepsis Mouse Model, A Proposal Sepsis Cell-Based Therapy, Dang Phi Cong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Sepsis, a systemic infection with excessive inflammatory symptoms due to dysregulation of immune responses, remains the most concerned health-care problem worldwide with the mortality rate critically beyond the number of death cases in HIV, cancers or stroke. While it is well documented that pathogenesis of sepsis is intimately involved in dysregulation of macrophages, great effort has been made to discover efficacious therapy to control macrophage responses. However, macrophages are the most versatile immune cells with large spectrum of heterogeneous phenotypes and functions. Recently, collection of insights unravel the crucial role of metabolism as an orchestrator of immune regulation, intervention on …

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High-Mobility Group Box 1 (Hmgb1) Mediates Dna Methylation Preventing Genomic Instability, Papitchaya Watcharanurak Jan 2020

High-Mobility Group Box 1 (Hmgb1) Mediates Dna Methylation Preventing Genomic Instability, Papitchaya Watcharanurak

Chulalongkorn University Theses and Dissertations (Chula ETD)

Global DNA hypomethylation promotes genomic instability through the accumulation of DNA damage and resulted in an increasing rate of mutation. To stabilize the genome, cells possess an epigenetic mechanism to reduce DNA tension that causes DNA damages, named Replication-Independent Endogenous DNA Double-Strand Breaks (RIND-EDSBs). Due to their biological roles, this type of physiologic EDSBs act as youth-associated genomic-stabilizing DNA gaps (Youth-DNA-GAPs). They are localized within methylated genome and maintained by non-histone HMGB1 and SIRT1 proteins. Reduction of RIND-EDSBs was found in hypomethylated genome, including cancer and aging. Therefore, this study aimed to explore the role of HMGB1-mediated DNA methylation in …

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Learning-Based Approach For Visual Quality Enhancement On High Efficiency Video Coding Standard, Sovann Chen Jan 2020

Learning-Based Approach For Visual Quality Enhancement On High Efficiency Video Coding Standard, Sovann Chen

Chulalongkorn University Theses and Dissertations (Chula ETD)

High Efficiency Video Coding (HEVC) has dramatically enhanced the coding efficiency compared to the previous video coding standard, H.264/AVC. However, the existing rate control updates its parameters according to a fixed initialization, which can cause error prediction of bit allocation to each coding tree unit (CTU) in frames. In this work, a learning-based mapping between rate control parameters and video contents is proposed to achieve an accurate target bit rate and good video quality. The proposed framework contains two main structural codings, including spatial and temporal coding. We initiate an effective learning-based particle swarm optimization for both spatial and temporal …

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Development Of An Integrated Microfluidic System For Cell Sorting And Trapping—Considering Sorting Efficacy And Cell Viability, Thammawit Suwannaphan Jan 2020

Development Of An Integrated Microfluidic System For Cell Sorting And Trapping—Considering Sorting Efficacy And Cell Viability, Thammawit Suwannaphan

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study is divided into two phases. The first phase is about the investigation of cell viability and damage of white blood cells after sorting in both a spiral microchannel and contraction and expansion array (CEA) at appropriate flow rates for cell separation. Three techniques such as Trypan Blue staining, Scanning Electron Microscopy (SEM) and Wright-Giemsa staining are employed in the experiments. After flowing the sample through a whole setup of spiral microchannel at 2 ml/min, 85% of cells are viable while 30% of cells are significantly deformed and 2% of cells are seriously damaged in their intracellular structures. In …

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Effect Of Food Impaction In The Interproximal Of Implant Supported Fixed Restoration Towards Oral Health Related Quality Of Life, Souknilan Chanthasan Jan 2020

Effect Of Food Impaction In The Interproximal Of Implant Supported Fixed Restoration Towards Oral Health Related Quality Of Life, Souknilan Chanthasan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Objectives: To investigate the effect of food impaction between dental implant and adjacent teeth to the patients’ quality of life and periodontal/peri-implant tissue conditions. Materials and methods: Patients with implant supported single crown (ISSC) having implant checkup at the Faculty of Dentistry, Chulalongkorn University between July 2019 and July 2020 were recruited. Food impaction was evaluated by either patients’ experience or clinical examination by dentist. Self-administrative Oral impacts on Daily Performance questionnaire was used to assess the effect of food impaction to patients’ quality of life. Clinical and radiographic examination was performed to evaluate periodontal/peri-implant tissue conditions. Results: Totally 178 …

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The Minimum Wage Change Effect To The Household Saving Between 2011 And 2013, Soraphong Smitintu Jan 2020

The Minimum Wage Change Effect To The Household Saving Between 2011 And 2013, Soraphong Smitintu

Chulalongkorn University Theses and Dissertations (Chula ETD)

In 2013, Thailand's minimum wage legislation change from multiple minimum wage levels in each province to a single national minimum wage. This study paper presents analyses of the relationship between the minimum wage change and low-income household savings. By using ordinary least square regression analysis. Sample data by Household Socio-economic survey in 2013 from National Statistical Office. The household saving is average monthly total income per household minus average monthly total expenditures per household. For a household to be considered as a low-income household, the household head must be between the ages of 18 and 60, have completed less than …

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Metabolite Profiling And Gene Expression Analysis In Starch And Sugar Metabolisms Of Ripening Durian Durio Zibethinus Pulp, Lalida Sangpong Jan 2020

Metabolite Profiling And Gene Expression Analysis In Starch And Sugar Metabolisms Of Ripening Durian Durio Zibethinus Pulp, Lalida Sangpong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Durian (Durio zibethinus L.), an economically important fruit of Southeast Asian countries, expresses unique flavor at the edible ripe stage, resulting from metabolic changes during the ripening process. Nevertheless, the study in such modulations is still limited. In the first manuscript, we profiled metabolites from unripe and ripe pulps of durian cv. Monthong using capillary electrophoresis- (CE) and gas chromatography- (GC) time-of-flight mass spectrometry (TOF/MS) and obtained the total 94 ripening-related metabolites from a combination of the two datasets, of which we focused on flavor-related metabolites. For sugar, sucrose is the most abundant sugar that increased during ripening, and the …

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The Deactivation Study Of Titanium Dioxide Catalyst In Thermochemical Processes Via Density Functional Theory, Chinanang Ngamlaor Jan 2020

The Deactivation Study Of Titanium Dioxide Catalyst In Thermochemical Processes Via Density Functional Theory, Chinanang Ngamlaor

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, the investigation of catalytic deactivation of TiO2 by coking was performed using DFT. The effect of the Hubbard U, which was varied as U equal 4 to 6 eV and Van der Waal corrections on electronic properties were also investigated. The effect of temperature in the range of 400-1000°C was also studied. This work aims to understand relatives of coke formation, oxygen vacancy, phase transformation. The increment of the Hubbard U values provide a more accurate quantitative cited by the energy gap from the experimental investigation, the appropriate U value of the A-TiO2 (101) is 4 eV, …

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The Deactivation Of Gamma-Alumina Based Catalyst During Aqueous Phase Reaction Using Density Function Theory, Phakaorn Aphichoksiri Jan 2020

The Deactivation Of Gamma-Alumina Based Catalyst During Aqueous Phase Reaction Using Density Function Theory, Phakaorn Aphichoksiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, biomass conversion has become a more attractive process to produce fuels and various high-value chemicals from biological materials. From many kinds of catalysts, the metal-supported gamma-alumina (γ-Al2O3) is a widely used catalyst for various transformation processes, especially in the aqueous phase reaction. Typically, coke formation on γ-Al2O3 causes catalyst deactivation in the thermal reaction process. Moreover, incorporation of aqueous phase medium initiates hydroxylation of γ-Al2O3 and phase transformation of γ-AlOOH, leading to the catalyst deactivation. Not only coke formation and phase transformation are the cause of catalytic deactivation, but the oxygen vacancy, changing the activity of the catalyst, should …

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Deactivation Of Manganese Dioxide Electrocatalyst In Zinc-Air Batteries Studied Via Density Functional Theory, Puwit Buapin Jan 2020

Deactivation Of Manganese Dioxide Electrocatalyst In Zinc-Air Batteries Studied Via Density Functional Theory, Puwit Buapin

Chulalongkorn University Theses and Dissertations (Chula ETD)

Manganese dioxide (MnO2) is the effective electrocatalysts used as a cathode for Zn-Air batteries (ZABs) accounted for the acceleration of the oxygen reduction reaction (ORR). There are various studies on the ORR activity of MnO2 rather than deactivation mechanisms. In this work, the deactivation mechanisms of α-MnO2 and β-MnO2 was investigated by density functional theory and computational hydrogen electrode. It was found that, the phase transformation from the α-MnO2 (211) to β-MnO2 (110) shows that the catalyst deactivation is due to the higher overpotential of β-MnO2 (110) making electrocatalyst efficiency low. For Ov surfaces, it illustrates that the performance is …

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Pelletization Of Cao Catalyst For Biodiesel Production Via Transesterification Of Palm Oil, Warisara Vornuch Jan 2020

Pelletization Of Cao Catalyst For Biodiesel Production Via Transesterification Of Palm Oil, Warisara Vornuch

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis investigates biodiesel production from palm oil by transesterification using extruded CaO catalysts. The preparation parameters of extruded CaO catalysts were investigated including 1) binder type including activated alumina, diatomite and kaolin, 2) calcination temperature at 700, 800 and 900°C, 3) mass ratio of CaO to the binder at 1: 1, 3: 1 and 6: 1. The Effect of catalyst shape of the extruded CaO and the addition of pore forming (polyacrylamide) on the catalytic activity of extruded CaO were also studied using transesterification using methanol to palm oil. The ratio of methanol to palm oil was fixed at …

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