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2021

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Safety Behaviour In Pesticide Use And Disposal Among Nigerian Cocoa Farmers, Oluseye Olalekan Oludoye Jan 2021

Safety Behaviour In Pesticide Use And Disposal Among Nigerian Cocoa Farmers, Oluseye Olalekan Oludoye

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nigerian cocoa farmers are indiscriminately using and disposing pesticides in a manner that poses danger to their health and the environment. Thus, sequential explanatory mixed methods design was used to explore personal and environmental determinants of pesticide safety and disposal behaviours among the farmers. Using face-to-face interviews, 391 cocoa farmers were interviewed based on a reliable and valid questionnaire consisted of the health belief model (HBM), disposal practices and sociodemographic questions. In the qualitative phase, in-depth interviews were conducted among 23 cocoa farmers and 34 relevant stakeholders to further explore the factors influencing safe pesticide use and disposal using the …

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นวัตกรรมอุปกรณ์ช่วยเดินที่มีระบบรองรับน้ำหนักแขน สำหรับผู้ป่วยพาร์กินสันที่มีปัญหาการเดินและการทรงตัว, ชนวัฒน์ อนันต์ Jan 2021

นวัตกรรมอุปกรณ์ช่วยเดินที่มีระบบรองรับน้ำหนักแขน สำหรับผู้ป่วยพาร์กินสันที่มีปัญหาการเดินและการทรงตัว, ชนวัฒน์ อนันต์

Chulalongkorn University Theses and Dissertations (Chula ETD)

การศึกษาวิจัยนี้ มีวัตถุประสงค์เพื่อการศึกษาแนวคิด ทัศนคติ ความต้องการใช้นวัตกรรมอุปกรณ์ช่วยเดินพร้อมทั้งมีการออกแบบและพัฒนานวัตกรรมอุปกรณ์ช่วยเดินต้นแบบ ทำการทดสอบใช้งานกับผู้ป่วยที่มีปัญหา การเดิน การทรงตัวและหลังโค้งงอ รวมถึงศึกษาการยอมรับผลิตภัณฑ์นวัตกรรมและโอกาสทางการตลาดมีการศึกษาวิจัยทั้งหมด 4 ระยะ ตามทฤษฎีของการพัฒนาผลิตภัณฑ์ใหม่ (New Product Development) ผลการวิจัย ระยะที่ 1 โดยการสัมภาษณ์เชิงลึก ผู้ป่วยโรคพาร์กินสัน ผู้ดูแล แพทย์และนักกายภาพบำบัด จำนวน 20 คน พบว่า ผู้ใช้งานให้ความสำคัญกับการแก้ไขปัญหาการหกล้ม ปัญหาการเดิน การทรงตัวและหลังโค้งงอ นวัตกรรมต้องมีการใช้งานง่าย มีความแข็งแรง ปลอดภัย ขนาดของผลิตภัณฑ์และสามารถใช้อุปกรณ์ได้ภายในบ้าน ระยะที่ 2 มีการออกแบบและพัฒนานวัตกรรมอุปกรณ์ช่วยเดิน จำนวน 2 รูปแบบ ได้แก่ รูปแบบที่ 1 แบบค้ำรักแร้ หรือ วงแขน และรูปแบบที่ 2 แบบรองรับน้ำหนักแขน เมื่อได้นวัตกรรมที่สมบูรณ์แล้วจึงมีการสัมภาษณ์เชิงลึก เพื่อคัดเลือกนวัตกรรม จำนวน 8 คน พบว่า ผู้เชี่ยวชาญเลือกนวัตกรรมรูปแบบที่ 2 จำนวน 6 คน ทางผู้วิจัยจึงนำนวัตกรรมรูปแบบที่ 2 นำไปพัฒนาต้นแบบผลิตภัณฑ์ (Prototype Development) ระยะที่ 3 ทดสอบเปรียบเทียบผู้ป่วยพาร์กินสันที่มีอาการหลังโค้งงอ จำนวน 7 คน อายุเฉลี่ย 68.14 ปี พบว่า ก่อนใช้อุปกรณ์ มีอาการหลังโค้งงอเฉลี่ย 42.43 องศา ขณะใช้อุปกรณ์มีอาการหลังโค้งงอเฉลี่ย 13.63 องศา แสดงให้เห็นว่าใช้อุปกรณ์แล้วอาการหลังโค้งงอดีขึ้น มีความแตกต่างกันอย่างมีนัยสำคัญทางสถิติที่ 0.05 ระยะที่ 4 ผลของการศึกษายอมรับผลิตภัณฑ์นวัตกรรม จำนวน 171 คน พบว่า มีระดับการยอมรับนวัตกรรมที่สูงทุกข้อ สนใจนวัตกรรมถึง 133 คน คิดเป็นร้อยละ 77.8 และสนใจซื้อนวัตกรรม จำนวน 87 คน …

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การประยุกต์เทคนิคบัญชีต้นทุนการไหลวัสดุในกระบวนการจัดการคลังสินค้า สำหรับบริษัท Xyz, มนต์ทิพย์ จันทราทิพย์ Jan 2021

การประยุกต์เทคนิคบัญชีต้นทุนการไหลวัสดุในกระบวนการจัดการคลังสินค้า สำหรับบริษัท Xyz, มนต์ทิพย์ จันทราทิพย์

Chulalongkorn University Theses and Dissertations (Chula ETD)

เทคนิคบัญชีต้นทุนการไหลวัสดุ (Material Flow Cost Accounting: MFCA) เป็นเทคนิคในการวิเคราะห์ต้นทุนความสูญเสียที่เกิดขึ้นในกระบวนการ มุ่งเน้นให้เกิดการใช้ทรัพยากรให้มีประสิทธิภาพรวมถึงการลดผลกระทบต่อสิ่งแวดล้อม งานวิจัยฉบับนี้มีวัตถุประสงค์เพื่อประยุกต์หลักการบัญชีต้นทุนการไหลวัสดุกับกระบวนการจัดการคลังสินค้า ส่งเสริมการใช้วัสดุให้มีประสิทธิภาพ และลดความสูญเสียในกระบวนการจัดการคลังสินค้าของบริษัท XYZ โดยเลือกกลุ่มสินค้าที่มีความคล่องตัวสูงมาทำการศึกษา จากนั้นทำการเก็บรวบรวมข้อมูลต้นทุนที่เกี่ยวข้องในแต่ละกระบวนการ และทำการวิเคราะห์ต้นทุนความสูญเสียตามหลักการบัญชีต้นทุนการไหลวัสดุ จากการศึกษาพบว่า ต้นทุนผลิตภัณฑ์ที่มีมูลค่าลบไม่ก่อให้เกิดรายได้แก่บริษัท พบในส่วนของต้นทุนวัสดุสูงที่สุด รองลงมาเป็นต้นทุนระบบและต้นทุนพลังงาน และพบว่าต้นทุนความสูญเสียของสินค้า Super Premium สินค้า Premium สินค้า Standard และสินค้า Economy คิดเป็นร้อยละ 0.044 ร้อยละ 0.062 ร้อยละ 0.089 และ ร้อยละ 0.158 ตามลำดับ เมื่อคิดคำนวณเป็นจำนวนเงินที่สูญเสียโดยรวมต่อวันของสินค้าทั้ง 4 ประเภทรวมเป็น 1,676.88 บาทต่อวัน ซึ่งความสูญเสียนี้เกิดขึ้นในกระบวนการจัดเตรียมสินค้า นอกจากนี้ยังพบว่า มูลค่าความสูญเสียนี้ ไม่ได้ถูกบันทึกอยู่ในระบบบัญชีปัจจุบันเนื่องจากการบันทึกบัญชีในปัจจุบัน เป็นการบันทึกบัญชีแบบดั้งเดิมที่รวมต้นทุนทุกอย่างไว้ด้วยกัน ไม่มีการจำแนกค่าใช้จ่ายในแต่ละประเภทสินค้าซึ่งยากต่อการแบ่งสัดส่วนต้นทุนต่าง ๆ ต่อประเภทสินค้า กิจกรรมหรือกระบวนการ ซึ่งแตกต่างจากการบันทึกบัญชีต้นทุนการไหลวัสดุที่สามารถแสดงให้เห็นถึงมูลค่าความสูญเสียนี้ได้

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Temporal Distribution Of Air Pollutants (Pm2.5, Pm10 And O3) In Yangon City, Myanmar During 2019-2021, Tin Saw Pyae Jan 2021

Temporal Distribution Of Air Pollutants (Pm2.5, Pm10 And O3) In Yangon City, Myanmar During 2019-2021, Tin Saw Pyae

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, the rise in air pollution can be seen around the world especially in urban city. Studying the distribution of air pollution becomes one of the essential ways to know the characteristics and nature of air pollutants for air pollution mitigation actions around the world. In Myanmar, there are very few studies focusing on this area and these very few studies were carried out for short term periods. Therefore, this study was aimed to investigate the temporal distribution of air pollutants (PM2.5, PM10 and O3) following by MLR modeling for the influence of meteorological factors on air pollutant concentrations and …

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Substrate Binding Mechanism Of Glycerophosphodiesterase Towards Pesticides And Improvement Of Stability By Mutational Analysis, Nayana Bhat Jan 2021

Substrate Binding Mechanism Of Glycerophosphodiesterase Towards Pesticides And Improvement Of Stability By Mutational Analysis, Nayana Bhat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Molecular dynamics studies have been providing a great number of atomistic details of biological systems to understand enzymatic activity and underlying reaction mechanisms. Herein, molecular dynamic (MD) simulations were employed to study the binding mechanisms of organophosphate pesticides towards two metallohydrolases, i.e., glycerophosphodiesterase (GpdQ) and methyl parathion hydrolase (MPH). OPH are the class of enzymes which breaks down harmful organophosphates, including the pesticides and warfare agents into less harmful byproducts. Hence, these enzymes are excellent candidates for bioremediation. In the present study, various nonspecific organophosphate pesticides were docked into GpdQ and MPH enzymes to construct the pesticide/protein complex for performing …

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Functional Characterization Of Rice Malate Synthase In Arabidopsis Responding To Salt Stress, Supisara Thanabut Jan 2021

Functional Characterization Of Rice Malate Synthase In Arabidopsis Responding To Salt Stress, Supisara Thanabut

Chulalongkorn University Theses and Dissertations (Chula ETD)

Salt stress is one of the major abiotic stresses that seriously limit plant growth and development and can lead to a significant reduction in crop yield, especially rice. Salt stress affects plants via ionic toxicity and osmotic stress. Osmotic stress results in a reduction of water absorption ability. Ionic toxicity causes Na+ toxicity, which disrupts photosynthesis, protein synthesis, and enzyme activity. The previous study of KDML105 rice transcriptome profile and qRT-PCR revealed that rice malate synthase (OsMS) encoding malate synthase, which is one of the key enzymes in glyoxylate cycle was up-regulated under salt stress, so OsMS may involve in …

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Analysis Of Protein-Protein Interaction Network From Leukocyte Transcriptomic Profiles In Severe Covid -19 Patients, Pakorn Sagulkoo Jan 2021

Analysis Of Protein-Protein Interaction Network From Leukocyte Transcriptomic Profiles In Severe Covid -19 Patients, Pakorn Sagulkoo

Chulalongkorn University Theses and Dissertations (Chula ETD)

Coronavirus disease 2019 (COVID-19) still provides global public health issues although several vaccines and antiviral agents have been developed. Some patients experience severe conditions needed medical intensive care, and some are dead due to the failure of treatments. Therefore, identifying the key genes and underlying molecular mechanisms is necessary to discover precisely targeted drugs. Analysis of protein-protein interaction (PPI) networks provides invaluable information to find disease mechanisms and effective alternative drugs. Hence, PPI network analysis based on leukocyte transcriptomic profiles of severe COVID-19 collected from Gene Expression Omnibus (GEO) DataSets was proposed for this study. A network diffusion method called …

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Development Of A Device For Postural Change While Sitting For The Prevention Of Neck Or Low Back Pain In Office Workers, Nipaporn Akkarakittichoke Jan 2021

Development Of A Device For Postural Change While Sitting For The Prevention Of Neck Or Low Back Pain In Office Workers, Nipaporn Akkarakittichoke

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of this thesis was to develop a device for postural change while sitting for the prevention of neck or low back pain in office workers. This thesis was divided into four stages: 1) to evaluate the effects of postural shifting frequency on perceived musculoskeletal discomfort during 1 hour of sitting in healthy office workers; 2) to evaluate the effects of the postural shift intervention on the 12-month incidence of the onset of neck and low back pain in high-risk office workers; 3) to investigate the efficacy of postural shift interventions on recovery duration and recurrence of neck and …

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Characterization Of Aberrant Mtor Signaling Pathway In U87mg Glioblastoma Cell Line By Quantitative Phosphoproteomics, Nuttiya Kalpongnukul Jan 2021

Characterization Of Aberrant Mtor Signaling Pathway In U87mg Glioblastoma Cell Line By Quantitative Phosphoproteomics, Nuttiya Kalpongnukul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Glioblastoma (GBM) is one of the most damaging primary brain tumors with a poor prognosis. GBM is associated with an abnormality of the mTOR signaling pathway, consisting of two distinct kinase complexes: mTORC1 and mTORC2. The protein complexes play critical roles in cellular metabolism, proliferation, cell survival, cell migration through the cytoskeletal organization, and DNA damage response in cancers. Nevertheless, the functions of mTORC2 are less unraveled. This study investigated the aberrant mTORC2 signaling pathway in glioblastoma cells using stable isotope labeling, phosphopeptide enrichment, and LC-MS/MS. We performed the quantitative phosphoproteomic analysis of U87MG grade IV glioma cells treated with …

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Epidemiology, Molecular Genetic, And Evolutionary Analysis Of Humanrotavirus A Infection In Thailand, Fajar Budi Lestari Jan 2021

Epidemiology, Molecular Genetic, And Evolutionary Analysis Of Humanrotavirus A Infection In Thailand, Fajar Budi Lestari

Chulalongkorn University Theses and Dissertations (Chula ETD)

Rotavirus A (RVA) infection remains one of the major causes of viral diarrhea in young children worldwide. Despite the success of RVA vaccines including RotaTeq in significantly reducing morbidity and disease severity associated with hospitalization, national immunization against RVA have only just begun in Thailand in 2020. Consequently, possible RV vaccine shedding among pediatric vaccine recipients has not been rigorously documented here.The first part of my study was summarize the virology, disease burden, prevalence, distribution of genotypes and seasonality of RVs, and the current status of RV vaccination in Southeast Asia (Cambodia, Indonesia, Lao People’s Democratic Republic, Malaysia, Myanmar, Philippines, …

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Deprogramming Senescence By Genomic Stabilizing Molecules In Vivo, Sakawdaurn Yasom Jan 2021

Deprogramming Senescence By Genomic Stabilizing Molecules In Vivo, Sakawdaurn Yasom

Chulalongkorn University Theses and Dissertations (Chula ETD)

Aging is the inevitable, time-dependent, natural process in all living cells, resulting from the accumulation of cellular damage with insufficient cell repair. Global hypomethylation and Alu (B1) hypomethylation become aging indicators, which are commonly found not only in cellular aging but also in human clinical studies of age-related diseases. Much evidence indicates that Alu (B1) hypermethylation could promote both mammalian and yeast cell growth and considerably increase cell survival by reducing the susceptibility to DNA-damaging agents. Also, Box-A of high mobility group box 1 (HMGB1), a DNA chaperone protein with different roles, is reported to be a genomic stabilizing protein …

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Analysis Of Influenza A Genomes And Bacterial Microbiota In Upper Respiratory Tracts Of Influenza Patients, Somruthai Rattanaburi Jan 2021

Analysis Of Influenza A Genomes And Bacterial Microbiota In Upper Respiratory Tracts Of Influenza Patients, Somruthai Rattanaburi

Chulalongkorn University Theses and Dissertations (Chula ETD)

Seasonal influenza is a contagious respiratory illness caused by influenza viruses that infect the upper respiratory tract (URT) of humans and represent a major burden for public health. Furthermore, the URT is colonized by a diverse microbial community which is a key factor protective from pathogens and may directly or indirectly affect viral infection. Therefore, the first aim of this study focuses on influenza A genome characterization and mutation analysis based on NGS technology. The phylogenetic analysis based on the deduced amino acid sequences revealed that the recommended vaccine (A/H1N1) strain might be less effective, whereas the recommended vaccine (A/H3N2) …

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Mrna Vaccine Encoding Neoantigen For Cancer Immunotherapy Using Mouse Melanoma As A Model, Chutamath Sittplangkoon Jan 2021

Mrna Vaccine Encoding Neoantigen For Cancer Immunotherapy Using Mouse Melanoma As A Model, Chutamath Sittplangkoon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cancer is the leading cause of death globally with an urgent need to find more effective approaches for prevention and treatment. mRNA vaccine is a promising vaccine platform over conventional vaccines in terms of safety, ease of large-scale production and effectiveness in inducing both cellular and humoral immune responses. Breakthrough in mRNA technology allowed novel strategies to improve mRNA stability and efficacy including nucleoside modifications. Modification of mRNA with N1-methylpseudouridine (m1Ψ) was reported to enhance protein expression and decrease innate immunogenicity due to low binding affinity to pattern recognition receptors, and low type I interferon (IFN-I) secretion. Therefore, this study …

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Association Between Gene Expression And Promoter Methylation Of Cgb3, Gstp1 And Nop56 Genes And Their Potential In Biomarker Development - Associated Cervical Cancer., Palak Singh Jan 2021

Association Between Gene Expression And Promoter Methylation Of Cgb3, Gstp1 And Nop56 Genes And Their Potential In Biomarker Development - Associated Cervical Cancer., Palak Singh

Chulalongkorn University Theses and Dissertations (Chula ETD)

Binding of DNMT1-E7 complex can induce promoter methylation in tumor suppressor genes, such as CCNA1, CADM1 leading to their expression suppression and thus, cause cancer progression. This research establishes the association between methylation-related expression of CGB3 and NOP56 genes in cervical cell lines treated with 5-Azacytidine drug. Using MSP-PCR and qPCR, it was found that the methylation of CGB3 and NOP56 were significantly decreased as concentration of 5-Aza increased and this was inversely related with their expression. This demonstrated the association between gene methylation and the regulation of gene expression which were assessed by 5’-aza drug treatment. Of note, the …

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Identification Of Α-Glucosidase Inhibitors From Black Garlic, Pattraporn Tantiwatcharachai Jan 2021

Identification Of Α-Glucosidase Inhibitors From Black Garlic, Pattraporn Tantiwatcharachai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Black garlic has emerged as one of the fastest-growing health food products on the market. It is processed by incubating fresh garlic under high temperature and high humidity conditions. The process causes the changes in characteristics of black garlic such as texture, flavor, nutrient contents, chemical composition and it pharmacological properties, especially antidiabetic activity. In the present investigation, we applied α-glucosidase inhibition guided isolation to identify active compounds. Four compounds named 5-hydroxymethylfurfural (5-HMF), 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), 4-(hydroxymethyl)phenol and 2-deoxy-ribono-1,4 lactone were isolated. On evaluation against α-glucosidase, HMFCA, 4-(hydroxymethyl)phenol, and 2-deoxy-ribono-1,4 lactone were active against maltase with IC50 values of 18.83 …

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Production And Characterization Of Mannanase From Aureobasidium Sp. For Mannooligosaccharide Preparation From Spent Coffee Ground, Syahriar Nur Maulana Malik Ibrahim Jan 2021

Production And Characterization Of Mannanase From Aureobasidium Sp. For Mannooligosaccharide Preparation From Spent Coffee Ground, Syahriar Nur Maulana Malik Ibrahim

Chulalongkorn University Theses and Dissertations (Chula ETD)

The aims of this study are to produce and characterize mannanase from the selected Thai Aureobasidium strain and use the enzyme for hydrolysis of spent coffee ground extract (SCGE) to prepare mannooligosaccharide (MOs). The optimum condition for SCGE extraction by hot water was 1:30 solid to liquid ratio with 60 min incubation time at 121°C 15 lbs per in2. The maximum yield was 9.5 g/100 g substrate. The second dominant composition of SCGE was hemicellulose at 28 %. Aureobasidium pullulans NRRL 58524 was selected as the best mannanase producer with 8.07 U/mL. The mannanase production medium was optimized by using …

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Proteomics Analysis Of Bt-474 And Skov-3 Cancer Cell Lines Treated With Purified Compounds From Bee Pollen And Cerumen, Teeranai Ittiudomrak Jan 2021

Proteomics Analysis Of Bt-474 And Skov-3 Cancer Cell Lines Treated With Purified Compounds From Bee Pollen And Cerumen, Teeranai Ittiudomrak

Chulalongkorn University Theses and Dissertations (Chula ETD)

Breast and gynaecological cancers are the main causes of global cancer death in females. So far, several compounds have been identified from traditional medicine components and natural products that exhibited anticancer activity. Previously, α-mangostin (α-MG) and apigenin (APG) had been extracted and purified from cerumen of Tetragonula laeviceps and bee pollen of Apis mellifera respectively. Preliminary studies reported that these compounds express antiproliferative activity in several cancer cell lines. In this study, α-MG and APG were investigated for antiproliferation effect in breast cancer cell line BT-474 and ovarian adenocarcinoma cell line SKOV-3 using MTT assay, fluorescent staining coupled with flow …

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Inhibitory Effects Of Propiconazole On Rice Root Development And Abilities Of Brassinosteroid And Auxin In Alleviating Its Effects, Watcharapong Wimonchaijit Jan 2021

Inhibitory Effects Of Propiconazole On Rice Root Development And Abilities Of Brassinosteroid And Auxin In Alleviating Its Effects, Watcharapong Wimonchaijit

Chulalongkorn University Theses and Dissertations (Chula ETD)

Propiconazole is commonly used as a fungicide to minimize crop loss caused by various fungal diseases in many crop plants, including rice. Propiconazole has the potentials to deteriorate the environmental problems due to its chemical properties that it is highly persistent in soil after application, suggesting that the constant use of propiconazole could be problematic. Hence, the evaluation of its effects on plant growth and development is necessary for the assessment of future use of propiconazole. Here, we demonstrated that propiconazole had inhibitory effects on plant growth. Treatments of propiconazole resulted in shoot dwarfism, abnormal leaf morphology, reduced plant biomass, …

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Epiphytic Microbiota Of Kai Cladophora Sp. From Nan River, Nan Province, Thailand, Karnjana Ruen-Pham Jan 2021

Epiphytic Microbiota Of Kai Cladophora Sp. From Nan River, Nan Province, Thailand, Karnjana Ruen-Pham

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cladophora is a cosmopolitan green algal genus in northern Thailand, commonly known as Kai or Sa Rai Kai, which the local people use for culinary and medicinal purposes. In nature, Cladophora acts as an ecological engineer in the ecosystem by creating, modifying, and maintaining the habitat by providing oxygen and microhabitats for several organisms, including prokaryotes and eukaryotes, namely epiphytic microbiota. These epiphytic microbiota living on the algal host's surface might exhibit crucial roles in the ecosystem. However, most understandings of the Cladophora microbiota were from the USA. Therefore, this study aims to investigate the Cladophora microbiota collected from Nan …

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Investigation Of Pm2.5 Dispersion In Din Daeng District, Bangkok Using Computational Fluid Dynamics Modeling, Amintra Tancharoen Jan 2021

Investigation Of Pm2.5 Dispersion In Din Daeng District, Bangkok Using Computational Fluid Dynamics Modeling, Amintra Tancharoen

Chulalongkorn University Theses and Dissertations (Chula ETD)

Din Daeng is a small and densely populated district of Bangkok with two major expressways in the area. PM2.5 concentrations in Din Daeng district often exceed both daily and annual standards of the National Ambient Air Quality Standards. Computational Fluid Dynamics (CFD) was applied to investigate the effects of the metropolitan characteristics and traffic volumes on the dispersion of PM2.5 in Din Daeng district. The turbulent flow was analyzed using the Standard k-ε model. There are two scenarios in this simulation study. One is to investigate the consequences of having the expressways and their resulting PM2.5 emissions. The other is …

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Electrochemical Synthesis Of Methoxide For Transesterification Of Palm Oil, Apiruedee Juntuma Jan 2021

Electrochemical Synthesis Of Methoxide For Transesterification Of Palm Oil, Apiruedee Juntuma

Chulalongkorn University Theses and Dissertations (Chula ETD)

Sodium methoxide (NaOCH3) is commonly used as an alkaline homogeneous catalyst in transesterification to produce fatty acid methyl ester (FAME) and glycerol as a by-product. However, this conventional process requires a few steps to remove the homogeneous catalyst from the products by neutralization and washing, creating waste salts to be treated with additional cost. This study investigates the electrochemical synthesis of methoxide. Amberlite IRA402 anion exchange resin is used to adsorb the generated methoxide and subsequently as a heterogeneous catalyst for transesterification to observe its catalytic activity. In contrast to many other similar works, this synthesis was performed with anion-exchange …

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Prediction Of Coke Formation Over A Catalyst Particle For Dry Reforming Of Methane, Chananun Rojanarungruengporn Jan 2021

Prediction Of Coke Formation Over A Catalyst Particle For Dry Reforming Of Methane, Chananun Rojanarungruengporn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, global warming is a significant environmental problem causing various impacts across the globe. Dry reforming of methane (DRM) is one of the reactions that can utilize CO2 effectively. However, the major problem of DRM process is the deactivation of catalysts caused by coke formation over the catalyst particle which mainly occurs from CH4 decomposition reaction. Coke formation leads to a decrease in catalytic performance by blocking the pores and active sites. In this study, the spatial catalyst deactivation caused by coke formation over a spherical alumina-supported nickel catalyst (Ni/Al2O3) particle in dry reforming of methane (DRM) was investigated using …

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Depolymerization Of Kraft Lignin To Phenolic Compounds By Electrochemical Advanced Oxidation In Microreactor, Chawakorn Rittirong Jan 2021

Depolymerization Of Kraft Lignin To Phenolic Compounds By Electrochemical Advanced Oxidation In Microreactor, Chawakorn Rittirong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research focuses on the depolymerization of kraft lignin to phenolic compounds that are valuable and useful in various industries. Depolymerization is performed using an electrochemical advanced oxidation process with the hydroxyl radicals. In this process, microreactors are used. It consists of a graphite anode and a stainless steel cathode. The results of the variables studied were current density (3.7 and 5.55 A/m2), residence time (100-400 s), base pH (9), the base difference (sodium hydroxide and potassium hydroxide). The experiment found that the major product is octadecamide and the minor product propyl guaiacol is increased when the current increases. On …

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Effect Of Cob Loading Amount In Gc3n4 Nanosheet In Photocatalytic Hydrogen Generation, Chayathorn Prapaitrakool Jan 2021

Effect Of Cob Loading Amount In Gc3n4 Nanosheet In Photocatalytic Hydrogen Generation, Chayathorn Prapaitrakool

Chulalongkorn University Theses and Dissertations (Chula ETD)

Noble metals, such as Pt, Ru, and Ir, have been widely used as expensive catalyst promoters to enhance the photocatalytic hydrogen evolution reaction (HER). In contrast, other cheaper catalyst promoters that can also promote high HER performance have been developed, such as metal phosphides, and metal borides. Recently, nickel boride (NiB) loaded on graphitic carbon nitride nanosheet (gCNS) has exhibited promising HER performance under visible light. Thus, this research attempted to investigate HER performance of cobalt boride (CoB) as a cocatalyst on gCNS and compare to the HER performance of NiB. The amount of CoB loading was varied from 1-11 …

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Synthesis Of Molybdenum-Based Catalysts On Carbon Support For Partial Hydrogenation Reaction Of Biodiesel, Dolrudee Jaruwat Jan 2021

Synthesis Of Molybdenum-Based Catalysts On Carbon Support For Partial Hydrogenation Reaction Of Biodiesel, Dolrudee Jaruwat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, biodiesel is a renewable energy, which can decrease fossil fuel. It helped reducing air pollution. Partial Hydrogenation is one process which improves the biodiesel quality. In this research, activated carbon was produced from cattail leave via hydrothermal carbonization and chemical activation. The activated carbon was treated with 4 M of potassium hydroxide at 900oC, which exhibits 1323.38 m2g-1 of SBET. Several type of catalysts (Mo, Ni, Ci, Fe, MoNi, MoCu, and MoFe) were studied in this research, which were prepared using a rotary evaporation technique. The experiments reveal that MoNi/C catalyst indicate the highest dispersion of metal particle. The …

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Effects Of Types Of Arylamine Based Benzoxazine Binders In Brake Pads On Thermal Degradation Kinetics, Juntasak Wangrangsimakul Jan 2021

Effects Of Types Of Arylamine Based Benzoxazine Binders In Brake Pads On Thermal Degradation Kinetics, Juntasak Wangrangsimakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aimed to investigate the effect of the alkyl-substituted aromatic amines of polybenzoxazine resins used as binders in the non-asbestos friction composite materials on their thermal degradation and stability. The effects of BA-35x polybenzoxazine resin used as a binder of the brake pad were investigated using thermogravimetric analysis (TGA) under nitrogen atmosphere at various heating rates of 1, 5, 10, 20 and 25 °C/min by applying the model of Advanced iso-conversional method. For the friction composite system using BA-35x as binder, the derivative thermogram exhibited six stages of thermal decomposition reaction. The activation energies of six stages were determined …

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Degradation Of Benzyl Phenyl Ether As Lignin Model Compound By Electrochemical Advanced Oxidation Process In A Microreactor, Kevin Lee Jan 2021

Degradation Of Benzyl Phenyl Ether As Lignin Model Compound By Electrochemical Advanced Oxidation Process In A Microreactor, Kevin Lee

Chulalongkorn University Theses and Dissertations (Chula ETD)

As the world is shifting away from its reliance on fossil fuel, lignocellulosic biomass, which is low cost, renewable and abundant with cellulose, hemicellulose and lignin being its major components. Lignin has high potential to be converted into other value-added chemicals as an alternative to fossil fuel. This research focusses on systematic investigation of degradation of lignin by electrochemical advanced oxidation process (EAOP) in a microreactor, using benzyl phenyl ether (BPE) as a model compound for lignin. The first part of the research investigates the dissolution of BPE in various volume fraction of co-solvent system. The co-solvent system is used …

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Synthesis Of Zinc Sulfide Nanoparticles Using Microemulsion Generated By Hydrodynamic Cavitation Method, Nachapa Choojan Jan 2021

Synthesis Of Zinc Sulfide Nanoparticles Using Microemulsion Generated By Hydrodynamic Cavitation Method, Nachapa Choojan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Zinc Sulfite (ZnS) nanoparticles have attracted attention of researchers as a promising material for semiconductor fabrication. Their optical properties are strongly size-dependent and related to production methodology. A microemulsion technique is simple and requires less energy to produce ZnS nanoparticles. However, this technique usually results in ZnS with a wide size distribution. In this work, microemulsion technique and hydrodynamic cavitation have been effectively combined for synthesis of ZnS nanoparticles with controllable and uniform size distribution. The microemulsion system which consists of water, cyclohexane, hexanol and Triton X-100 surfactant has been prepared by incorporating hydrodynamic cavitation. Experimental results number of passages, …

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Controllable Formation Of Microparticles Via Microfluidic Technique, Narin Paiboon Jan 2021

Controllable Formation Of Microparticles Via Microfluidic Technique, Narin Paiboon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Droplet microfluidics is an interesting tool in the encapsulation process due to its potentiality for microparticles and microcapsules fabrication with uniform size and narrow size distribution. The formation of water-in-oil (W/O) emulsion droplets in a microfluidic flow-focusing device for microparticles production were investigated under a wide selection of operating parameters together with liquid materials. Experimental results of 12 data sets from over 100 experiments in two different-sized channels were assessed. The stable narrowing jet and tip streaming regime noticeably created monodisperse droplet formation with high throughput. The droplet size to junction size has been found to correlate with the three …

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Development Of Rotating Tube Reactor For Biodiesel Production From Palm Oil, Narita Chanthon Jan 2021

Development Of Rotating Tube Reactor For Biodiesel Production From Palm Oil, Narita Chanthon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Rotating tube reactor (RTR), one of process intensification technologies, could highly increase the mixing performance and generate sufficient heat for biodiesel production. This research explored the optimum condition, essential characteristics of hydrodynamic regime and residence time distribution inside the rotating tube reactor (RTR) to enhance the biodiesel production rate using alkali-catalyzed transesterification. The operating condition of this RTR was 6:1 methanol-to-oil molar ratio, total flowrate of 30 mL/min and rotational speed of 1,000 rpm at room temperature, giving the highest biodiesel yield of 97.5% with yield efficiency of 3.75 × 10-3 g/J and the quality of biodiesel achieving the ASTM …

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