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2021

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การระบุสารประกอบกลิ่นสำคัญของใบกะเพราแดงสด "Ocimum Tenuiflorum L.” และสารที่เกี่ยวข้องกับการเกิดกลิ่นผิดปกติในกะเพราหลังการให้ความร้อน, ชลพร ศรีพรม Jan 2021

การระบุสารประกอบกลิ่นสำคัญของใบกะเพราแดงสด "Ocimum Tenuiflorum L.” และสารที่เกี่ยวข้องกับการเกิดกลิ่นผิดปกติในกะเพราหลังการให้ความร้อน, ชลพร ศรีพรม

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ได้ใช้กระบวนการเซนโซมิกส์ (sensomics approach) ในการศึกษาเพื่อระบุสารระเหยที่มีศักยภาพที่จะเป็นสารให้กลิ่นสำคัญ (odor-active compounds) ของใบกะเพราแดงสดและสารที่เกี่ยวข้องกับการเกิดกลิ่นผิดปกติหลังให้ความร้อนด้วยไมโครเวฟ โดยใช้ผู้ทดสอบ 8 คน ทำการทดสอบและประเมินลักษณะกลิ่นของตัวอย่างใบกะเพราแดงสดและใบกะเพราแดงที่มีกลิ่นผิดปกติหลังให้ความร้อนด้วยไมโครเวฟ พบว่า ผู้ทดสอบสามารถอธิบายลักษณะเฉพาะ (attribute) ของใบกะเพราแดงสดได้ 5 กลิ่น ได้แก่ กลิ่นกะเพรา กลิ่นฉุน กลิ่นกานพลู กลิ่นส้มเปรี้ยว และกลิ่นเขียว สำหรับใบกะเพราแดงที่มีกลิ่นผิดปกติหลังให้ความร้อนด้วยไมโครเวฟ พบ 5 ลักษณะเฉพาะของกลิ่น เหมือนกันกับตัวอย่างใบกะเพราแดงสด ยกเว้น กลิ่นอับ ที่เป็นลักษณะเฉพาะของกลิ่นที่ทำให้เกิดกลิ่นผิดปกติ จากนั้นสกัดตัวอย่างด้วยตัวทำละลาย DCM (dichloromethane) นำสารสกัดที่ได้มาสกัดด้วย เทคนิค SAFE (solvent-assisted flavor evaporation) เพื่อแยกสารระเหย (volatiles) ออกจากสารระเหยยาก (non-volatiles) ได้ส่วนสกัดของสารระเหยที่เป็นของเหลว ใส ไม่มีสี และนำมาทำให้สารสกัดเข้มขึ้นด้วยวิธีการกลั่นลำดับส่วนด้วย Vigruex column และ microdistillation จนได้ส่วนสกัดของสารระเหยในปริมาตร 1-2 มิลลิลิตร จากนั้นนำมาวิเคราะห์ด้วยเครื่อง GC-O/FID โดยใช้คอลัมน์ DB-FFAP และ DB-5 เพื่อหาลักษณะ (character) ของสารให้กลิ่นในแต่ละ retention time และใช้เทคนิค AEDA (aroma extract dilution analysis) เพื่อคัดเลือกสารให้กลิ่นที่มีศักยภาพเป็นสารให้กลิ่นสำคัญ โดยระบุเป็นค่า FD Factor (flavor dilution factor) พบ สารให้กลิ่นของใบกะเพราแดงสดที่มีค่า FD factor ≥ 4 ทั้งหมด 24 ชนิด โดยสารให้กลิ่นที่มีค่า FD factor สูงสุดคือ สารให้กลิ่นคล้ายกลิ่นกะเพรา (FD: 1024) รองลงมา สารให้กลิ่นคล้ายกลิ่นดิน (FD: 512) สารให้กลิ่นคล้ายกลิ่นปัสสาวะ …

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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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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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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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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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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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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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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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Norfloxacin Adsorption By Activated Carbon From Turmeric Waste, Nuttamon Vanichsetakul Jan 2021

Norfloxacin Adsorption By Activated Carbon From Turmeric Waste, Nuttamon Vanichsetakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

In recent years, extensive use of modern medicines and incompetency of conventional wastewater treatment systems have led to contamination of antibiotics in the environment especially in lower income countries. Antibiotics could interact with bacteria in the environment forming resistance to the medicine. Antibiotics also disrupt the balance of ecosystems affecting various lifeforms. Norfloxacin is a common antibiotic in Thailand with reported levels of contamination in Bang Pakong River. Adsorption process is a cheap and effective approach to remove antibiotics from wastewater effluent. Activated carbon is a common adsorbent in adsorption process due to its porous properties. Agricultural waste presents as …

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Tetracycline Sorption By Magnetic Biochar Derived From Watermelon Rind: Performance And Influential Factors, Phisit Thairattananon Jan 2021

Tetracycline Sorption By Magnetic Biochar Derived From Watermelon Rind: Performance And Influential Factors, Phisit Thairattananon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Tetracycline (TC) antibiotic is one of emerging contaminants in water reservoirs that causes undesirable effects on environment and human health. Magnetic biochar (MBC) is considered a promising sorbent in adsorption process for removal of contaminants with highly efficient and facile operation. In this work, MBC was synthesized by pyrolysis of watermelon rind impregnated with FeCl3 at different pyrolysis temperatures in a range of 600-900 °C prior to applying for TC adsorption. Characteristics of MBC were analyzed by scanning electron microscopy, elemental analyzer, N2 adsorption/desorption, Fourier-transform infrared spectroscopy, Raman spectroscopy, vibrating sample magnetometry, and X-ray diffractometry. The adsorption kinetics, isotherm, effect …

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Process Of Pretreatment And Hydrolysis Of Lignocellulose From Palm Empty Fruit Bunch For Xylose And Glucose Production, Pitchaya Teerakulkittipong Jan 2021

Process Of Pretreatment And Hydrolysis Of Lignocellulose From Palm Empty Fruit Bunch For Xylose And Glucose Production, Pitchaya Teerakulkittipong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Oil palm empty fruit bunch is an interesting lignocellulose feedstock for sugar production. However, lignin prohibits chemicals from accessing the hemicellulose and cellulose, which is the source of sugar. Therefore, the overall process requires pretreatment to remove lignin and hydrolysis to convert hemicellulose and cellulose to sugar. In this research, the aim is to design a process model of sugar production using different pretreatment chemicals, including alkaline (NaOH) and acid (H2SO4), and compare the other necessary following process. Moreover, capital investment is also estimated. According to the results, different pretreatment chemicals results in a different change of lignocellulose structure and …

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Effect Of Bismuth (Bi) Concentration On Bi/Sn Electrodes Prepared By Electrodeposition In Electrochemical Reduction Of Co2 To Toward Solid Carbon Products, Sarita Phupaichitkun Jan 2021

Effect Of Bismuth (Bi) Concentration On Bi/Sn Electrodes Prepared By Electrodeposition In Electrochemical Reduction Of Co2 To Toward Solid Carbon Products, Sarita Phupaichitkun

Chulalongkorn University Theses and Dissertations (Chula ETD)

Carbon dioxide (CO2) is the main greenhouse gas that contributes to climate change. The electrochemical carbon dioxide reduction (CO2RR) is an interesting and low-cost CO2 conversion technology using renewable electricity as an energy source. Herein, CO2RR to solid carbon products was studied on bismuth/tin (Bi/Sn) electrodes synthesized by electrodeposition method. Different Bi concentration (0.01 M,0.03 M, 0.05 M,0.07 M and 0.1 M) were used to prepare the electrodes by electrodeposition method. The SEM-EDX and EIS results which reveal that the Bi/Sn electrode prepared in 0.05 M Bi 3+ had the lowest charge transfer resistance and was indicated as a CO2RR …

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Electrochemical Reduction Of Carbon Dioxide On Copper-Based Cathodes In Electrochemical Tubular Fixed Bed Reactor, Kanjira Janya Jan 2021

Electrochemical Reduction Of Carbon Dioxide On Copper-Based Cathodes In Electrochemical Tubular Fixed Bed Reactor, Kanjira Janya

Chulalongkorn University Theses and Dissertations (Chula ETD)

CO2 electrochemical reduction reaction (CO2ERR) has been investigated with an aim to eventually become a means to decrease the concentration of CO2 in the atmosphere to hydrocarbons by proton and electron transfer. The product distribution strongly depends on cathode materials. Copper is a unique metal in its ability to catalyze the electrochemical reduction of CO2 to various hydrocarbons including ethylene, but the main problems are the poor solubility CO2 in aqueous solutions. In this study, the performance of CO2ERR is improved by increasing pressure. The ionomer copper foam is used as a cathode in the electrochemical tubular fixed bed reactor …

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Mesoporous Carbon/Silica Nanocomposites With Acid And Base Properties For Glucose Conversion Into Value Added Chemicals, Satit Yousatit Jan 2021

Mesoporous Carbon/Silica Nanocomposites With Acid And Base Properties For Glucose Conversion Into Value Added Chemicals, Satit Yousatit

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this study is to prepare mesoporous carbon/silica (MCS) nanocomposites using natural rubber (NR) as a renewable carbon source. A series of mesoporous nanocomposites based on NR and hexagonal mesoporous silica (HMS), prepared via an in situ sol-gel process, were used as precursors, which were then converted into the MCS materials by carbonization. The sulfonic acid-functionalized mesoporous carbon/silica (MCS-SO3H) was prepared by direct sulfonation with H2SO4 solution. The silica surface of MCS-SO3H were then grafted by 3-aminopropyltrimethoxysilane to produce the acid–base catalysts (MCS-SO3H-NH2) and used as the solid catalysts in glucose conversion. The MCS nanocomposites exhibited enhanced structural, …

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Cellulose-Supported Fluorophore As Metal Ion Sensors, Apiwat Promchat Jan 2021

Cellulose-Supported Fluorophore As Metal Ion Sensors, Apiwat Promchat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Organic fluorescent ligands are attractive for qualitative and quantitative analysis of metal ions. Cellulose substrates, especially for filter paper, have been demonstrated as one of the most economical and easy to use platform for fluorescent sensors applied in on-site analysis with naked-eye observation. In this work, new series of amidoquinoline derivatives were synthesized and investigated as the fluorescent ligands for developing paper-based sensors. The sensors are used for convenient analysis either by simple naked-eye observation or an image processing software. In the first part of this dissertation, parallel solid-state synthesis on filter paper macroarray was used for rapid discovery and …

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Use Of Modified Nay Zeolite As Ionophore For Perchlorate Selective Electrode, Boonyakorn Srisassawatkul Jan 2021

Use Of Modified Nay Zeolite As Ionophore For Perchlorate Selective Electrode, Boonyakorn Srisassawatkul

Chulalongkorn University Theses and Dissertations (Chula ETD)

NaY zeolite is well deserved for being employed as a catalyst, adsorbent, and ion exchanger. Therefore, its ion exchange property is used in ion selective electrodes (ISEs). Commercial NaY zeolite was modified with cetyltrimethylammonium bromide (CTAB) in various concentrations (100, 150, and 200 mM), denoted them as 100, 150 and 200 SMZ, respectively. XRD, FT-IR, SEM and TGA/DTG showed good agreement of CTAB adsorption on zeolite surface. Then SMZ is used to fabricate polymeric membrane with polyvinyl chloride (PVC) plasticized with o-nitrophenyl octyl ether (o-NPOE). The best performance of ISE was exhibited at the membrane composition of 200 SMZ: PVC: …

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Chemical Constituents Of Fan-Si Abutilon Indicum Stems, Arum Restu Widyasti Jan 2021

Chemical Constituents Of Fan-Si Abutilon Indicum Stems, Arum Restu Widyasti

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to isolate secondary metabolites from the stems of Abutilon indicum and to evaluate their α-glucosidase, pancreatic lipase, α-chymotrypsin inhibitory activity. Chromatographic fractionation of the n-hexane crude extracts led to the isolation of three known metabolite (1-3). The crude extract from all parts of the plant were evaluated for inhibitory activity on the alpha-glucosidase enzyme. The DCM-soluble roots were active with 10.2% at 25 μg/mL. The hexane and MeOH-soluble stems were active with 11.0% at 25 μg/mL and 8.0% at 0.25 μg/mL. The hexane, DCM, and MeOH-soluble leaves are active with 20.2% at 0.025 μg/mL; 20.0% at 0.025 …

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Modification Of Screen-Printed Carbon Electrode For Detection Of Pesticides, Kansuda Langor Jan 2021

Modification Of Screen-Printed Carbon Electrode For Detection Of Pesticides, Kansuda Langor

Chulalongkorn University Theses and Dissertations (Chula ETD)

Methyl parathion (MP) is an organophosphate pesticide broadly used in agriculture to protect crops and fruits from the damages caused by insects and pests. However, when it is used in large quantities, it can be potentially toxic to humans and animals, causing many poisoning effects. Moreover, its residues can also penetrate the food chain (via agriculture food products) as well as contaminating the environment, leading to air, water and soil pollution. Therefore, rapid determination and reliable quantification of trace level of MP are crucially needed for food safety and environmental monitoring. In this work, a low-cost and portable electrochemical sensor …

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Colorimetric And Fluorescent Detection Of Nucleic Acid By Styryl Dyes, Kotchakorn Supabowornsathit Jan 2021

Colorimetric And Fluorescent Detection Of Nucleic Acid By Styryl Dyes, Kotchakorn Supabowornsathit

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nucleic acid staining dyes are essential tools for the analysis and visualizing of DNA/RNA in vitro and in cellular applications. Although there are several commercially available dyes developed during the past few decades, the selection is still relatively limited, and they are often very costly and associated with undesirable characteristics such as toxicity. Consequently, the discovery of nontoxic, readily available dyes, with desirable and controllable optical characteristics remains important. Styryl dyes have recently gained popularity as potential biological staining agents with many desirable properties including a straightforward synthesis procedure, excellent photostability, tunable optical properties, and high responsiveness towards nucleic acid …

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Synthesis Of Quantum Dot-Based Fluorescent Sensors For Detection Of Anionic Metabolites And Copper (Ii) Ion, Nattakarn Phromsiri Jan 2021

Synthesis Of Quantum Dot-Based Fluorescent Sensors For Detection Of Anionic Metabolites And Copper (Ii) Ion, Nattakarn Phromsiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Oxalate, citrate, and urate are the anionic metabolites that are the products of the metabolism pathway of living organisms. The high level of these anionic metabolites is related to the diseases. For example, the excess amount of oxalate ions in urine indicates the risk of kidney stones, while the level of citrate can suggest the risk of cancer. The level of urate in urine is related to the risk of gout. The detection of these anionic metabolites is significant and still remains a challenge. Thus, this work aims to develop the more sensitive and selective fluorescence sensing of oxalate in …

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