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Effects Of Types Of Arylamine Based Benzoxazine Binders In Brake Pads On Thermal Degradation Kinetics, Juntasak Wangrangsimakul
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 …
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 …
Synthesis Of Zinc Sulfide Nanoparticles Using Microemulsion Generated By Hydrodynamic Cavitation Method, Nachapa Choojan
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, …
Controllable Formation Of Microparticles Via Microfluidic Technique, Narin Paiboon
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 …
Development Of Rotating Tube Reactor For Biodiesel Production From Palm Oil, Narita Chanthon
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 …
Cathodized Stainless Steel Mesh For Binder-Free Nife2o4/Nife Ldh Oxygen Evolution Reaction Electrode, Natthapon Sripallawit
Cathodized Stainless Steel Mesh For Binder-Free Nife2o4/Nife Ldh Oxygen Evolution Reaction Electrode, Natthapon Sripallawit
Chulalongkorn University Theses and Dissertations (Chula ETD)
Oxygen evolution reaction (OER) is an essential reaction commonly applied in various energy storage and conversion technologies. One of the common issues of OER lies in its low kinetic activity. Therefore, developing durable, low-cost, and high-performance OER catalysts is critical. Recently, many attempts have used stainless steel mesh (SSM) as the substrate for OER electrodes because SSM is abundant, cheap, and durable. Nickel/iron-based materials, i.e., NiFe2O4/NiFe layer double hydroxides (LDHs), are regarded as one of the most excellent OER catalysts in alkaline electrolytes, making them attractive low-cost materials for OER catalysts. However, the synthesis of NiFe2O4/NiFe LDHs directly on the …
Manganese Dioxide Coated With Tin Oxide As Cathode Material For High-Performance Aqueous Zinc-Ion Battery., Nichakarn Meekaew
Manganese Dioxide Coated With Tin Oxide As Cathode Material For High-Performance Aqueous Zinc-Ion Battery., Nichakarn Meekaew
Chulalongkorn University Theses and Dissertations (Chula ETD)
Rechargeable aqueous zinc-ion batteries (ZIBs) have attracted increasing attention as an energy storage technology due to their high energy density, low cost, and environmental friendliness. However, the application of manganese dioxide as the cathode for aqueous Zn-ion batteries (ZIBs) is restricted by the solubility of manganese dioxide in aqueous electrolytes and the formation of byproducts during the charge/discharge process, causing severe capacity fading and limited cycle life. Surface modification is one of the interesting techniques to improve zinc-ion batteries electrochemical performance. Here, we report an ultrathin SnO2 film as an artificial solid electrolyte interphase (SEI) to modify the surface of …
Norfloxacin Adsorption By Activated Carbon From Turmeric Waste, Nuttamon Vanichsetakul
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 …
Electrochemical Tubular Fixed-Bed Reactor For Conversion Of Pressurized Co2 To Co, Pakawat Sengchim
Electrochemical Tubular Fixed-Bed Reactor For Conversion Of Pressurized Co2 To Co, Pakawat Sengchim
Chulalongkorn University Theses and Dissertations (Chula ETD)
Electrochemical CO2 reduction reaction (CO2RR) can be used for activating the stable CO2 molecule to the more active CO for downstream purposes. Usually, this process is carried out in CO2-saturated aqueous solutions. The low solubility of CO2 in water of 0.033 M at 1 bar of CO2 and room temperature hinders both kinetics and mass transfer. In this study, a novel electrochemical tubular reactor for electrochemical CO2RR is proposed. The design was made with ease of scale-up in mind. A reactor can contain multiple electrochemical cells connected in series. Each cell consists of 3 main parts: porous anode, porous solid …
Tetracycline Sorption By Magnetic Biochar Derived From Watermelon Rind: Performance And Influential Factors, Phisit Thairattananon
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 …
Process Of Pretreatment And Hydrolysis Of Lignocellulose From Palm Empty Fruit Bunch For Xylose And Glucose Production, Pitchaya Teerakulkittipong
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 …
The Prediction Of Pm2.5 Dispersion In Bangkok (Pathumwan District)Using Cfd Modeling, Punyisa Chaisri
The Prediction Of Pm2.5 Dispersion In Bangkok (Pathumwan District)Using Cfd Modeling, Punyisa Chaisri
Chulalongkorn University Theses and Dissertations (Chula ETD)
City configuration, meteorological conditions and emission source are the important factors affecting the concentration and dispersion of pollutants within urban street canyon. The dispersion of PM2.5 in Pathumwan district, Bangkok which has a characteristics of street canyon was predicted using a Computational Fluid Dynamics (CFD) model. Flow and dispersion of PM2.5 were analyzed using standard k-ε turbulence model. The concentrations of PM2.5 were investigated under different conditions to demonstrate the effect of city configuration in study area, meteorological characteristics, and lockdown due to COVID-19 on PM2.5 concentration. The numerical model was validated with the measured data from the air quality …
Effect Of Bismuth (Bi) Concentration On Bi/Sn Electrodes Prepared By Electrodeposition In Electrochemical Reduction Of Co2 To Toward Solid Carbon Products, Sarita Phupaichitkun
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 …
Preparation Of Nickel Phyllosilicate Catalysts By One-Step Modified Spherical Silica Synthesis In Carbon Dioxide Hydrogenation And Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Sasithorn Kuhaudomlap
Preparation Of Nickel Phyllosilicate Catalysts By One-Step Modified Spherical Silica Synthesis In Carbon Dioxide Hydrogenation And Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Sasithorn Kuhaudomlap
Chulalongkorn University Theses and Dissertations (Chula ETD)
Spherical silica derived nickel phyllosilicate catalysts were prepared via a one-step modified spherical silica synthesis under room temperature. For 10wt% Ni loading, the loading sequence of Ni and Si sources during spherical silica synthesis was found to affect the characteristics and catalytic properties in CO2 methanation. The stronger interaction between Ni and silica in the form of nickel phyllosilicate revealed the better catalytic performances than the impregnation method. The highest CO2 methanation activity and methane selectivity were obtained over the catalyst prepared by alternate loading between Ni and Si (Ni_Alt_Si) due to high electron density of nickel on the surface, …
Liquid-Phase Selective Hydrogenation Of Furfural To Furfuryl Alcohol Over Pt- And Ptfe-Incorporated Mesoporous Carbon, Sureeporn Saknaphawuth
Liquid-Phase Selective Hydrogenation Of Furfural To Furfuryl Alcohol Over Pt- And Ptfe-Incorporated Mesoporous Carbon, Sureeporn Saknaphawuth
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research aims to investigate the liquid-phase selective hydrogenation of furfural to furfuryl alcohol in a batch reactor at 50ºC, 20 bar H2 using water and methanol as the solvent. This study has been divided into two sections. The characteristics and catalytic properties of OMC-supported Pt catalysts (Pt/OMC-one-pot) prepared by one-step modified soft-template self-assembly method were compared with the Pt impregnated on OMC, activated carbon (AC), and non-uniform meso/macroporous carbon (MC) in the first section. Larger Pt particle size (~4 nm) was obtained on the Pt/OMC-one-pot comparing to all the impregnated ones, in which the Pt particle sizes were in …
Electrochemical Reduction Of Carbon Dioxide On Copper-Based Cathodes In Electrochemical Tubular Fixed Bed Reactor, Kanjira Janya
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 …
Synthesis Of Magnetic Carbon Nanotubes Via Co-Pyrolysis Of Eucalyptus Oil With Bimetallic Ni-Fe Catalyst, Tanapat Rodruangnon
Synthesis Of Magnetic Carbon Nanotubes Via Co-Pyrolysis Of Eucalyptus Oil With Bimetallic Ni-Fe Catalyst, Tanapat Rodruangnon
Chulalongkorn University Theses and Dissertations (Chula ETD)
Magnetic carbon nanotubes (MCNTs) have been specified one of the most promising nanomaterials. They have been applied in many applications due to special electrical, mechanical, and chemical properties. Additionally, magnetic carbon nanotubes could be easily handled by using magnetic field. There are many production developments for increasing in yield and quality of MCNTs. In this thesis, bimetallic Ni-Fe catalyst was investigated for its possibility to improve MCNT synthesis. Nickel content was impregnated on the surface of ferrocene which is the source of Fe content. The catalyst is called ‘ferrocene impregnated with nickel nitrate’. Eucalyptus oil, which mainly contains eucalyptol, was …
Development Of Nonaqueous Zinc-Ion Battery Based On Manganese Dioxide Cathode, Wathanyu Kao-Ian
Development Of Nonaqueous Zinc-Ion Battery Based On Manganese Dioxide Cathode, Wathanyu Kao-Ian
Chulalongkorn University Theses and Dissertations (Chula ETD)
Zinc-ion batteries (ZIBs) are considered promising candidates for large-scale applications replacing lithium-ion batteries (LIBs). ZIBs having aqueous electrolytes have many advantages being low-cost, safe, and eco-friendly. However, a number of shortcomings hinder their application e.g. self-corrosion, hydrogen evolution, and Zn dendrite-formation. To mitigate these issues, nonaqueous electrolytes i.e. organic-based and room temperature ionic liquid electrolytes have been proposed. Nevertheless, nonaqueous electrolytes are yet to be elucidated. Herein, this work identifies nonaqueous electrolytes' state of the art and develops a new nonaqueous electrolyte system for ZIBs based on a manganese dioxide (MnO2) cathode. For this purpose, Zn chemistry in nonaqueous electrolytes …
Carbon Dioxide Hydrogenation To Methane Over Silica Supported Nickel Catalysts In A Differential Reactor And Kinetic Model Development, Angkana Khuenpetch
Carbon Dioxide Hydrogenation To Methane Over Silica Supported Nickel Catalysts In A Differential Reactor And Kinetic Model Development, Angkana Khuenpetch
Chulalongkorn University Theses and Dissertations (Chula ETD)
Development of a kinetic model for CO2 methanation over a commercial nickel catalyst was performed to consider pathways of CO2 conversion via Sabatier and RWGS reactions. H2/CO2 ratio in the feed gas composition was varied at the stoichiometry of the Sabatier reaction assuming a fictitious CO2 conversion of 0 to 0.7. Non-stochiometric gas feeding and the addition of product gases, i.e., methane and steam, were also considered to examine reaction orders and inhibition effects. The kinetic tests were carried out at 300–350 °C and 0.1–0.9 MPa. GHSV corresponded to 37,494 h-1. The stable activity was achieved by forcibly stressing the …
Mesoporous Carbon/Silica Nanocomposites With Acid And Base Properties For Glucose Conversion Into Value Added Chemicals, Satit Yousatit
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, …
Synthesis And Catalytic Activity Of Layered Double Hydroxide And Metal Sulfide Nanoparticle Composites, Ajirawadee Suwanchan
Synthesis And Catalytic Activity Of Layered Double Hydroxide And Metal Sulfide Nanoparticle Composites, Ajirawadee Suwanchan
Chulalongkorn University Theses and Dissertations (Chula ETD)
Degradation of methylene blue dye was investigated over heterogenous catalytic process using layered double hydroxide and metal sulfide nanoparticle composites. CuCo2S4/NiFe LDH nanocomposites were synthesized using hydrothermal method, and the composites were characterized by SEM and XRD techniques. CuCo2S4 and NiFe LDH were formed with an average particle in the range of 350-450 nm and 2200-3500 nm, respectively. The composites were loaded at 1.8, 3.4, 5.2 and 9.9 wt% of CuCo2S4. CuCo2S4, NiFe LDH and CuCo2S4/NiFe LDH composites were tested at the same condition for methylene blue degradation. The 18CuCo2S4/NiFe LDH composites provided higher catalytic degradation of methylene blue compared …
Synthesis Of Baicalein Derivatives As Anti-Dengue Agents, Apinya Patigo
Synthesis Of Baicalein Derivatives As Anti-Dengue Agents, Apinya Patigo
Chulalongkorn University Theses and Dissertations (Chula ETD)
Dengue, a mosquito-borne viral disease, is now considered a major international health concern, and hence the development of a new anti-dengue drug is highly desirable. Baicalein is a flavone isolated from the roots of Scutellaria baicalensis and Scutellaria lateriflora. Baicalein derivatives have been shown previously to exhibit a promising anti-dengue activity. In this study, five novel and thirteen known baicalein derivatives were synthesized via semi synthesis from baicalein with modifications at C-5, -6, -7, and -8 positions on ring A and a six-step total synthesis with modifications at the para position on the ring B with a range of electron-withdrawing …
Cellulose-Supported Fluorophore As Metal Ion Sensors, Apiwat Promchat
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 …
Use Of Modified Nay Zeolite As Ionophore For Perchlorate Selective Electrode, Boonyakorn Srisassawatkul
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: …
Chemical Constituents Of Fan-Si Abutilon Indicum Stems, Arum Restu Widyasti
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 …
Modification Of Screen-Printed Carbon Electrode For Detection Of Pesticides, Kansuda Langor
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 …
Colorimetric And Fluorescent Detection Of Nucleic Acid By Styryl Dyes, Kotchakorn Supabowornsathit
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 …
Hydrogen Gas Sensing And Storage Properties Of Doped And Non-Doped Beryllium Oxide Nanotubes, Kritsanaphas Sawing
Hydrogen Gas Sensing And Storage Properties Of Doped And Non-Doped Beryllium Oxide Nanotubes, Kritsanaphas Sawing
Chulalongkorn University Theses and Dissertations (Chula ETD)
The electronic properties of armchair (5,5) beryllium oxide nanotube (BeONT), zigzag (10,0) BeONT, and their surfaces doped by the selected elements of periods 2 (B, C and N), 3 (Mg, Al, Si, P and S) and 4 (Ca, Ga, Ge, As and Se), and their hydrogen molecule adsorptions were studied using periodic DFT‒D method. The C(O)‒ and Ge(O)‒(5,5) BeONTs, C(O)‒, Si(O)‒ and Ge(O)‒(10,0) BeONTs were suggested to be new hydrogen molecule sensing materials based on the electrical resistivity measurement. The C(O)‒, Si(O)‒ and Ge(O)‒doped (5,5) BeONTs, and C(O)‒ and Si(O)‒doped (10,0) BeONTs were suggested to be utilized as hydrogen storage …
Synthesis Of Quantum Dot-Based Fluorescent Sensors For Detection Of Anionic Metabolites And Copper (Ii) Ion, Nattakarn Phromsiri
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 …
Boron Nanomaterials And Small Molecules Adsorption, Nontawat Ploysongsri
Boron Nanomaterials And Small Molecules Adsorption, Nontawat Ploysongsri
Chulalongkorn University Theses and Dissertations (Chula ETD)
The adsorption abilities of hydrogen boride nanotubes and nanosheet were studied. The adsorption of H2, H2O, NH3 and CH4 on the most stable armchair and zigzag hydrogen boride nanotubes and their C, N and O decorated nanotubes were investigated by using density functional tight binding (DFTB) method. The results show that C-decorated armchair and zigzag HBNTs could be the NH3 storage materials and N-decorated armchair and zigzag HBNTs could be water vapor sensing materials. The adsorption of Li, Na and K atoms on armchair like (5,5) and zigzag like (10,0) HBNTs and hydrogen adsorption on Li, Na and K decorated …