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2018

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Electrochemical Detection Of Herbicides And Antioxidants Using Nanomaterial-Modified Electrode, Kanokwan Charoenkitamorn Jan 2018

Electrochemical Detection Of Herbicides And Antioxidants Using Nanomaterial-Modified Electrode, Kanokwan Charoenkitamorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation focused on the development of a novel nanomaterial-based electrochemical sensors for pharmaceutical and environmental applications. The research is divided into two parts. In the first part, a low-cost and disposable sensor for the simultaneous determination of coenzyme Q10 (CoQ10) and α-lipoic acid (ALA) using manganese (IV) oxide-modified screen-printed graphene (MnO2/SPGE) electrode was developed. The incorporated MnO2 in the SPGE can greatly enhance the detection performance towards the oxidation of CoQ10 and ALA. The cyclic voltammetry (CV) and square-wave anodic stripping voltammetry (SWASV) were employed to investigate the electrochemical behavior of the developed sensor and also to perform the …

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Dft And Dftb Investigations On Α–Mangostin Dye Adsorbed On Titanium Dioxide Electrode In Dsscs Application, Kanthira Kaewsud Jan 2018

Dft And Dftb Investigations On Α–Mangostin Dye Adsorbed On Titanium Dioxide Electrode In Dsscs Application, Kanthira Kaewsud

Chulalongkorn University Theses and Dissertations (Chula ETD)

Conformations of α–mangostin dye (1,3,6–Trihydroxy–7–methoxy–2,8–bis(3–methyl–2–buten–1–yl)–9H–xanthen–9–one) were studied and three conformers were found as three co-existing species in various media (in vacuo, acetonitrile and water). Geometries, electronic structures and UV–Vis spectra of all conformers in various media have been obtained using density functional theory (DFT) and time–dependent DFT (TD–DFT) methods. The conformers of α–mangostin dye were inspected as photosensitizers for application in dye sensitized solar cells (DSSCs) and their light–harvesting efficiencies (LHEs) within the range of 0.6757–0.7556 eV (in vacuo), 0.8286–0.8466 eV (in acetonitrile) and 0.8288–0.8465 eV (in water) were obtained. The open circuit voltage (VOC) of three conformers within the …

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Speciation Of Arsenic Using Sulfur Containing Ligand And Cotton Wool By Icp-Oes, Kavee Triteeyaprasert Jan 2018

Speciation Of Arsenic Using Sulfur Containing Ligand And Cotton Wool By Icp-Oes, Kavee Triteeyaprasert

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aimed to develop a method for speciation of arsenic species including As(III) and As(V) in environmental samples. Cotton wool and sulfur containing ligands including ammonium pyrrolidinedithiocarbarmate (APDC), L–cysteine and diethyldithiocarbamic acid were used in a solid phase extraction and determination of arsenic by using inductively coupled plasma optical emission spectrometry. The separation parameters were studied including pH, ligand concentration, cotton amount, type of eluents and flow rate. It was found that at pH 2, 0.1% APDC concentration and 0.5 g of cotton, As(III) could form complex with APDC (As(III) – APDC) and was separated from As(V) by using …

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Green Synthesis Of Gold Nanoparticles Using Wax Leaved Climber Cryptolepis Buchanani Latex And Biological Activities, Kittiphong Tongsuk Jan 2018

Green Synthesis Of Gold Nanoparticles Using Wax Leaved Climber Cryptolepis Buchanani Latex And Biological Activities, Kittiphong Tongsuk

Chulalongkorn University Theses and Dissertations (Chula ETD)

Gold nanoparticles (AuNPs) is the one of nanodrug carriers that have been popular in the current trend. To prepare AuNPs for biomedical applications, many techniques have been developed. However, both physical and chemical methods may cause energy consuming and toxic residues so green synthesis would be the most appropriate method for the preparation of AuNPs. The green synthesis of AuNPs could be provided by utilizing of fungi, bacteria and plant. In this work, we focused to use plant latex as reducing and stabilizing agents for the synthesis of AuNPs. The latex was collected from Cryptolepis buchanani, a folk medicinal plant …

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Sequence Specific Nucleic Acid Sensing By Pyrrolidinyl Peptide Nucleic Acid And Nanomaterials, Kriangsak Faikhruea Jan 2018

Sequence Specific Nucleic Acid Sensing By Pyrrolidinyl Peptide Nucleic Acid And Nanomaterials, Kriangsak Faikhruea

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, fluorescence and colorimetric nucleic acid sensing platforms based on pyrrolidinyl peptide nucleic acid (acpcPNA) probe and nanomaterials including graphene oxide (GO), reduced graphene oxide (rGO), gold nanoparticles (AuNPs), and silver nanoparticles (AgNPs) were developed. The acpcPNA probe was modified by multiple lysine residues to provide positive charges which enhanced the adsorption of the probe to various types of nanomaterials. In fluorescence detection mode, this results in higher quenching efficiency, resulting in lower background signal. Recovery of the quenched fluorescence signal was achieved upon hybridization with the complementary DNA/RNA target due to the displacement of the probe from …

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C-O Bond Formation On C-5 Of 2,4-Diaminopyrimidines, Natthakorn Uppatam Jan 2018

C-O Bond Formation On C-5 Of 2,4-Diaminopyrimidines, Natthakorn Uppatam

Chulalongkorn University Theses and Dissertations (Chula ETD)

This work aims to find a robust oxidation condition that can efficiently convert 2,4-diaminopyrimidines to its C5-hydroxylated derivative. Although Boyland-Sims oxidation of these substrates has been reported, this procedure suffers low yield and poor reproducibility. The conditions for Boyland-Sims oxidation of 2,4-diaminopyrimidines were thus re-optimized. The parameters that could affect the yields of the 5-hydroxy products were investigated using 2,4-diamino-6-ethylpyrimidine as a model compound. The reactions were performed at 0.10 mmol scale of the starting pyrimidine. The yields of the products were monitored by 1H NMR spectroscopy with reference to an internal standard. The reaction was reproduced at larger scale …

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Synthesis Of Hydroxyapatite Nanoparticles For Polynucleotides Delivery In Dentistry, Natthaya Thepphanao Jan 2018

Synthesis Of Hydroxyapatite Nanoparticles For Polynucleotides Delivery In Dentistry, Natthaya Thepphanao

Chulalongkorn University Theses and Dissertations (Chula ETD)

Hydroxyapatite (HAp) nanoparticles-based miRNA delivery system has emerged as a promising therapeutic agent for bone regeneration application. In order to achieve high therapeutic performance, the development of HAp functions remains challenging. This study describes the influence of HAp characters on their biological activities with osteoblast cell by synthesized different sizes of rod-like HAp with 150-200 and 100 nm in size and the different shape of elongated particles with 100-150 nm in size. A comparison was carried out on cytotoxicity, cellular uptake, and miRNA binding capacities. The elongated and rod-like shapes of 100-150 nm illustrated the high cell viability, and interestingly, …

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Glycosylation Of Thioglycosides With Bromodiethylsulfonium Bromopentachloroantimonate As Novel Activator, Ladawan Punrum Jan 2018

Glycosylation Of Thioglycosides With Bromodiethylsulfonium Bromopentachloroantimonate As Novel Activator, Ladawan Punrum

Chulalongkorn University Theses and Dissertations (Chula ETD)

Glycosylation is an important reaction in carbohydrate synthesis of complex molecules such as oligosaccharides, glycoproteins, and glycolipids. Thioglycosides are widely used as precursors in oligosaccharide synthesis due to their ease of preparation, high stability towards protecting group manipulations and variety of activation methods. Recently, bromodiethylsulfonium bromopentachloroantimonate (BDSB) was reported as a novel source of highly electrophilic bromine. It was used to efficiently initiate cation-π cyclizations of polyene at low temperature. Herein, we report a chemical glycosylation of thioglycosides activated by BDSB. Firstly, armed and disarmed glycosyl donors and glycosyl acceptors were synthesized by using modified previous method. Next, several reaction …

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Metalloporphyrin-Sensitized Titania/Silica/Iron Oxide Nanocomposites And Their Photocatalytic Activities, Padtaraporn Chanhom Jan 2018

Metalloporphyrin-Sensitized Titania/Silica/Iron Oxide Nanocomposites And Their Photocatalytic Activities, Padtaraporn Chanhom

Chulalongkorn University Theses and Dissertations (Chula ETD)

New nanomaterials of the magnetic visible light active photocatalysts, tetra(4-carboxyphenyl)porphyrin (TCPP) with different metals [Mn(II), Fe(III), Cu(II), Zn(II) and metal-free] in the center adsorbed on titania-silica-iron oxide superparamagnetic composites (TSI) were synthesized successfully. The photocatalytic activities in methylene blue (MB) degradation were determined under incandescent lamp for 3 h. Their characteristics have been identified using UV-visible spectroscopy, X-ray diffractometry (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The photodegradation results revealed that the metalloporphyrin sensitization helped TSI to absorb the light in visible region. Titania-silica-iron oxide nanomaterials with copper(II) tetra(4-carboxyphenyl)porphyrin (CuTCPP) can significantly …

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Molecular Simulations Of Voltage-Gated Proton-Selective Channel, Panisak Boonamnaj Jan 2018

Molecular Simulations Of Voltage-Gated Proton-Selective Channel, Panisak Boonamnaj

Chulalongkorn University Theses and Dissertations (Chula ETD)

Voltage-gated proton-selective channels (Hv1) are a membrane protein that permeates proton across cell membranes. They play an important role in various physiological processes. Hv1 was found as a dimer in membranes. Molecular mechanisms underlying the proton conduction of Hv1 have been a subject of intense research but is still remained unclear. In this study, molecular dynamics (MD) simulations of Hv1 were carried out to gain better understanding of the structure-function relationship. The first part of this thesis involved with an investigation of the role of the C-terminal domain (CTD) in stabilizing the dimer structure of Hv1. MD data showed the …

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Fluorescent Sensors From Salicylaldimine Derivatives For Metal Ions, Phoom Sangsuwan Jan 2018

Fluorescent Sensors From Salicylaldimine Derivatives For Metal Ions, Phoom Sangsuwan

Chulalongkorn University Theses and Dissertations (Chula ETD)

An in-situ forming and sensing was developed as a high-throughput screening of fluorescent chemosensors for metal ions. The 45 salicylaldimines, formed in-situ from the condensation between 5 salicylaldehydes and 9 amines, in 96 well-plates were photographed under black light along with the 5 salicylaldehydes in the absence and presence of 18 metal ions. The library of fluorescence response images of these 50 chemosensors were processed into RGB values. The PCA of theΔRGB, the differences between those of images with and without the metal ions, showed 9 sensors with normalized loading value over 70%. The sensor array constructed from these 9 …

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Hybrid Materials From Covalent Organic Frameworks And Ionic Liquids, Ranida Maliyaem Jan 2018

Hybrid Materials From Covalent Organic Frameworks And Ionic Liquids, Ranida Maliyaem

Chulalongkorn University Theses and Dissertations (Chula ETD)

Covalent organic frameworks (COFs) are new type material, whereby their wide range of properties derived from the chemistry of frameworks and their regular porosity. Here in, we reported the successful syntheses of the novel hybrid materials between porous COF material and ionic liquids (ILs). The crystalline porous powder of boroxine‑based COF, so called COF‑5, is reproducible via a condensation reaction between hexahydroxyltriphenylene and phenyldiboronic acid under a mild condition using a conventional heating method. The as‑synthesized COF-5 was characterized with PXRD, FT-IR, TGA and BET techniques, showing that the material contained 1D regular channels caused by π-π stacking of the …

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Detection Of Sulfonamide Residues By Paper Spray Mass Spectrometry, Surased Suraritdechachai Jan 2018

Detection Of Sulfonamide Residues By Paper Spray Mass Spectrometry, Surased Suraritdechachai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Sulfonamide antibiotics are commonly used veterinary drugs in livestock to prevent or treat infectious diseases. Their residues in food are of concern since they can cause adverse health effects and development of bacterial resistance. In this work, a practical method for detection and quantification of sulfamethazine, one of sulfonamide antibiotics, in pig body fluid samples is developed via the combination of simple extraction and paper spray mass spectrometry. The method required minimal sample preparation and low analysis time while providing high sensitivity and accuracies in pig whole blood (LOD = 10.1 ng/mL, %recovery = 95.4-104.1%), pig serum (LOD = 4.6 …

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Fabrication And Mechanical Properties Of Hyaluronic Acid Microneedle Arrays For Transdermal Drug Delivery, Teeranut Rutwaree Jan 2018

Fabrication And Mechanical Properties Of Hyaluronic Acid Microneedle Arrays For Transdermal Drug Delivery, Teeranut Rutwaree

Chulalongkorn University Theses and Dissertations (Chula ETD)

Dissolvable microneedles have been widely investigated as an alternative of hypodermic injection or other drug delivery methods. Various polymers have been used to fabricate microneedles. Type of polymers affects mechanical properties and dissolution rate of microneedles. In this study, five formulations of hyaluronic acid (HA)/ polyvinylpyrrolidone (PVP) composite microneedle patches (HA/PVP at 100/0, 75/25, 50/50, 25/50, 0/100) were fabricated. The crosslinked HA microneedles were also fabricated. Mechanical properties of the obtained microneedles were determined by universal testing machine and durometer. The skin-penetration ability and dissolution rate of HA/PVP microneedles were also investigated using porcine skin. The results show that microneedle …

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Synthesis Of Halogenated Flavonoids As Anti-Dengue Agents, Thao Huynh Nguyen Thanh Jan 2018

Synthesis Of Halogenated Flavonoids As Anti-Dengue Agents, Thao Huynh Nguyen Thanh

Chulalongkorn University Theses and Dissertations (Chula ETD)

Flavonoids have been recognized as promising compounds with various bioactivities. Certain flavonoid derivatives exhibited more potent activities than their parent compounds. Recently, halogenated flavonoids have been addressed for their anti-dengue activity. In this research, a series of twenty-two brominated and iodinated flavonoid derivatives were synthesized and explored for dengue infection inhibition. Seventeen derivatives have been investigated for the first time. 8-Bromobaicalein, 6,8-dibromopinocembrin, 6,8-dibromopinostrobin, 6,8-diiodopinostrobin were disclosed as effective and non-toxic anti-dengue agents. These compounds displayed remarkably low EC50 as well as high CC50, which could be considered as potent therapeutic agents. Moreover, the preliminary screening on brominated O7-ether chrysins discovered …

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Benzimidazole Derivatives Of Perylene Diimide For Organic Field-Effect Transistor, Tianchai Chooppawa Jan 2018

Benzimidazole Derivatives Of Perylene Diimide For Organic Field-Effect Transistor, Tianchai Chooppawa

Chulalongkorn University Theses and Dissertations (Chula ETD)

The poor solubility of perylene derivatives has been a key factor that prohibits the application of these thermally stable compounds in organic field-effect transistors (OFET) devices. In this research, the effort to enhance the solubility and exploring FET property of benzimidazole derivatives of perylene diimide were investigated. The perylene diimide core structure was functionalized by aryloxy moieties. Unfortunately, the isomeric products were still poorly soluble in common organic solvents, which made them impossible to separate and purify. Thus, the synthetic plan and goal were completely revised to the benzotriazatruxene derivatives, which were highly soluble in organic solvents such as dichloromethane …

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Green Synthesis Of Gold Nanoparticles Using Natal Lily Crinum Moorei Extract And Biological Activities, Warinda Marujiwat Jan 2018

Green Synthesis Of Gold Nanoparticles Using Natal Lily Crinum Moorei Extract And Biological Activities, Warinda Marujiwat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Crinum moorei as medical herb has different pharmacological activities such as anti-cancer and anti-inflammatory properties. Gold nanoparticle (AuNP) is an interesting anti-cancer drug carrier which can solve anti-cancer drug's problems with good biocompatibility, non-toxicity and suitable size for the intracellular uptake to treat to the target cells. From the beginning, other reducing agents were used to synthesize AuNPs. However, they lead to the contamination of chemicals on AuNP's surfaces which limits the medical application or long process and time consuming. Therefore, plant extracts were studied to make a remarkable dual function: the synthesized AuNPs agent and drug agent. In this …

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Development Of Headspace-Solid Phase Microextraction And Gas Chromatography-Mass Spectrometry/Olfactometry For Analysis Of Volatile Compounds From Chicken Products, Wongkanok Yoosong Jan 2018

Development Of Headspace-Solid Phase Microextraction And Gas Chromatography-Mass Spectrometry/Olfactometry For Analysis Of Volatile Compounds From Chicken Products, Wongkanok Yoosong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Gas chromatography-mass spectrometry/olfactometry coupled headspace solid phase microextraction (HS-SPME-GC-MS/O) was applied to analysis of volatile compounds from raw chickens and boiled chickens. The HS-SPME was 50/30 mm DVB/CAR/PDMS. The extraction temperature of boiled chicken was 50 °C for 30 min and raw chicken were extracted at room temperature. The SPME Probes were analyzed by GC-MS with a HP-5MS capillary column. 16 volatile compounds were identified in the boiled chickens in four chemical classes including aldehydes, aromatic hydrocarbon, alcohols and ketones and 20 volatile compounds were identified in raw chickens in three chemical classes including aldehydes, alcohols and esters. The identification …

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Synthesis And Antidiabetic Activity Of Furofuran Lignans Containing Multiphenolic Groups, Titiruetai Doungwichitrkul Jan 2018

Synthesis And Antidiabetic Activity Of Furofuran Lignans Containing Multiphenolic Groups, Titiruetai Doungwichitrkul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Synthesis of furofuran lignans containing multiphenolic groups (6-12) was carried out. The starting material samin (5) was obtained by acid hydrolysis of sesamin (2), which was isolated from sesame seed oil. A series of target lignans were synthesized from samin (5) and a varity of phenolics through Friedel-Crafts reaction, yielding desired products (6). To increase number of hydroxy moieties on the synthesized lignans, oxidative reaction using lead (IV) tetraacetate was performed. Removal of methylenedioxy of furofuran lignans containing a phenolic moiety produced unexpected products which contains para-quinone together with ortho-dihydroxy moieties on furofuran core structures (8-9). Consequently, to avoid oxidation …

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Analysis Of Cracked Body Repaired By Adhesively Bonded Patches By Bem-Fem Coupling, Binh Viet Pham Jan 2018

Analysis Of Cracked Body Repaired By Adhesively Bonded Patches By Bem-Fem Coupling, Binh Viet Pham

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents an efficient numerical technique capable of handling the stress analysis of three-dimensional cracked bodies strengthened or repaired by adhesively bonded patches. The proposed technique is implemented within the framework of the coupling of the weakly singular boundary integral equation method and the standard finite element procedure. The former is applied to efficiently treat the elastic body containing cracks whereas the latter is adopted to handle both the adhesive layers and the patches. The approximation of the near-front relative crack-face displacement is enhanced by using local interpolation functions that can capture the right asymptotic behaviour. This also offers …

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The Relationship Of Influential Factors On Material Management Effectiveness In Building Construction Projects: Case Study In Vietnam, Bao Van Pham Jan 2018

The Relationship Of Influential Factors On Material Management Effectiveness In Building Construction Projects: Case Study In Vietnam, Bao Van Pham

Chulalongkorn University Theses and Dissertations (Chula ETD)

The improvement of management processes in construction could be seen as one of the important keys to project success in which material management should be appropriately taken into consideration. Although many previous research studies have examined the components of construction material management, the relationship of factors influencing material management effectiveness has not been explored. This study was carried out to identify influential factors on material management effectiveness and develop a model to explain the relationships between these factors and the effectiveness of material management based on practical projects. The research method included the collection of contractors' opinions in building projects …

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Sbfe Analysis Of Layered Elastic Media With Consideration Of Surface Energy Effect, Chantha Chhuon Jan 2018

Sbfe Analysis Of Layered Elastic Media With Consideration Of Surface Energy Effect, Chantha Chhuon

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents an efficient and accurate numerical technique for determining mechanical response of a two-dimensional, infinite, elastic, layered medium under arbitrary surface loading and surface stress effects. Governing equations of a generic bulk layer are formulated from the classical linear elasticity theory via a SBFE technique whereas those of the generic material surface are obtained from a full version of Gurtin-Murdoch surface elasticity theory. The formulation is established sufficiently general allowing both homogenous and functionally graded bulk materials to be treated for each layer. By enforcing the continuity at the interface of the material surface and the bulk, it …

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Compression Behavior Of Fire-Damaged Concrete-Filled Steel Tubular Columns Confined With Fiber-Reinforced Polymer Sheets, Dat Thanh Vu Jan 2018

Compression Behavior Of Fire-Damaged Concrete-Filled Steel Tubular Columns Confined With Fiber-Reinforced Polymer Sheets, Dat Thanh Vu

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research investigates the axial compression behavior of fire-damaged circular concrete-filled steel tube (CFST) stub columns externally confined with fiber-reinforced polymer (FRP) sheets. A total of 38 CFST specimens were tested under axial compression to investigate the load capacity, ductility, stiffness and failure mode of fire-damaged CFST columns before and after strengthening with FRP sheets. The test variables include the level of fire damage (no damage and 2-hour ISO standard fire), compressive strength of infill concrete (24MPa and 55MPa), type of FRP sheets (carbon and glass), and the number of FRP layers (0, 1, and 2 layers). The test results …

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A Bim-Database-Integrated System For Evaluating Building Life-Cycle Costs Using A Multi-Parametric Model, Hang Thi Thu Le Jan 2018

A Bim-Database-Integrated System For Evaluating Building Life-Cycle Costs Using A Multi-Parametric Model, Hang Thi Thu Le

Chulalongkorn University Theses and Dissertations (Chula ETD)

Life-cycle cost analysis (LCCA) has become an essential requirement of the sustainable procurement for many construction projects. Conventional building LCCA methods are extremely complex and time-consuming due to repetitive works, numerous required data, scattered data inputs, and various regulatory requirements, which subsequently lead to inaccurate building life-cycle costs (LCC). Building information modeling (BIM) offers a revolutionary information technology, which can overcome the asperities of the conventional building LCCA. This research develops the BIM-database-integrated system for evaluating building life-cycle costs using a multi-parametric model (BIM-BLCC). The BIM-BLCC consists of four interrelated modules. The relational database management module collects and organizes the …

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Improved Response Spectrum Analysis Procedure For Design Of Reinforced Concrete Tall Buildings, Kimleng Khy Jan 2018

Improved Response Spectrum Analysis Procedure For Design Of Reinforced Concrete Tall Buildings, Kimleng Khy

Chulalongkorn University Theses and Dissertations (Chula ETD)

Response spectrum analysis (RSA) procedure commonly used in design practice has been found to underestimate design forces in tall buildings. Failure and damage of reinforced concrete (RC) shear walls in mid-rise and high-rise buildings have been observed in recent earthquakes. In this dissertation, a modified RSA (MRSA) procedure to compute shear forces and strains in RC walls and columns to identify locations requiring ductile detailing was proposed. Six tall RC shear-wall buildings of 15 to 39 stories and four RC moment-frame buildings of 3 to 15 stories subjected to earthquake ground motions expected in Bangkok and Chiang Mai were first …

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Development Of Causal Relationship Model Of Knowledge Sharing In Construction Projects, Lambada Roeun Jan 2018

Development Of Causal Relationship Model Of Knowledge Sharing In Construction Projects, Lambada Roeun

Chulalongkorn University Theses and Dissertations (Chula ETD)

Knowledge sharing among construction project members is very crucial for improving project success and project performance. It can also reduce mistakes in the construction process. Project management has been growing more complicated, and project members need to learn best practice from others. Currently, knowledge sharing is not well performed yet; especially, few research studies have been focused on the relationship evaluation of supporting factors that affect knowledge sharing from different contexts in construction projects. Therefore, this study aims to develop the causal relationship model of supporting factors from psychological, individual, organizational, and technological factors that affect mediators - knowledge sharing …

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The Influences Of Granite Particle As A Mixing Material Of High-Strength Concrete, May Thazin Khine Jan 2018

The Influences Of Granite Particle As A Mixing Material Of High-Strength Concrete, May Thazin Khine

Chulalongkorn University Theses and Dissertations (Chula ETD)

The aim of this study is to investigate the effect of granite particle on the properties of high strength concrete by the partial substitution as fine aggregate. By grouping two categories as concrete with and without admixture is also performed in this experiment. The granite particle substitution percentage for concrete with admixture is set with 0%, 20%, 30%, 40% and 50% by weight of fine aggregate and 0%, 10%, 15% and 20% by weight of fine aggregate for concrete without admixture. The testing of concrete strength is conducted with compressive, split tensile, flexural, water permeability, and microstructure. The result shows …

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Geophysical Site Investigation And Ground Response Analysis Of Bangkok Subsoil Due To Earthquake, Muhammad Fatih Qodri Jan 2018

Geophysical Site Investigation And Ground Response Analysis Of Bangkok Subsoil Due To Earthquake, Muhammad Fatih Qodri

Chulalongkorn University Theses and Dissertations (Chula ETD)

The potential damages on building and infrastructure could be affected by long-distance earthquakes since the vibrations can appear ground motion amplification during the wave propagation. Bangkok urban area is located a hundred kilometers away from the potential area of the earthquake epicenter. However, some people in Bangkok could feel the shaking during the earthquake. It indicates that the long-period shaking could happen during the earthquake. In line with this phenomenon, this study aims to interpret the amplification effect and spectral acceleration in the local site of Bangkok due to remoted earthquakes. The microtremor measurement was conducted at four locations in …

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Nonlinear Finite Element Analysis Of Steel Pipe With Stiffener Plate, Rut Su Jan 2018

Nonlinear Finite Element Analysis Of Steel Pipe With Stiffener Plate, Rut Su

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents the numerical studies of steel hollow section columns connected to corbels under industry crane loads, and the stiffening design using steel plates to enhance the maximum loading capacity against premature local buckling failures. The influences of inelastic material properties and geometry nonlinearity on the overall load carrying capacity of the columns were considered. Square hollow section columns were modelled in 3D using standard eight-node solid finite elements using an ANSYS software. The plate stiffener design algorithm involving variation of plate thicknesses was coded in MATLAB with a direct application programming interface to ANSYS. The full history of …

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Mechanical Performances Of Concrete Beams With Hybrid Usage Of Steel And Frp Reinforcement, Linh Van Hong Bui Jan 2018

Mechanical Performances Of Concrete Beams With Hybrid Usage Of Steel And Frp Reinforcement, Linh Van Hong Bui

Chulalongkorn University Theses and Dissertations (Chula ETD)

Fiber-reinforced polymer (FRP) bars have been recently employed to reinforce concrete members due to their high tensile strength and especially in corrosive environments to improve the durability of concrete structures. However, FRP composites have a low modulus of elasticity and a linear elastic behavior up to rupture, thus reinforced concrete (RC) components with such materials would express a lack of ductility. In order to increase the mechanical performances of RC beams, the hybrid usage (also called combined usage) of FRP and steel reinforcements in shear and flexure is proposed. At first, an experimental investigation of concrete beams strengthened in shear …

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