Small Specimen Test Techniques For Evaluating Radiation-Induced Changes In Mechanical Properties,
2012
Boise State University
Small Specimen Test Techniques For Evaluating Radiation-Induced Changes In Mechanical Properties, Ellen Marie Rabenberg
Boise State University Theses and Dissertations
The mechanical properties of as-received and irradiated 304 stainless steel (304SS) were evaluated by the shear punch and miniature tensile techniques. A purpose of this study was to evaluate the shear punch technique itself, which is a less developed technique versus miniature tensile testing. This was accomplished in part by comparing yield and ultimate strengths obtained from shear punch and miniature tensile data. The tests were further correlated by evaluating the mechanical properties of aluminum 6061 and Inconels 600 and 718. A linear relationship was observed between the shear strength and tensile strength data, providing a correlation between the two …
Production Of Poly-?-Glutamic Acid By Bacillus Licheniformis: Synthesis And Characterization,
2012
Chulalongkorn University
Production Of Poly-?-Glutamic Acid By Bacillus Licheniformis: Synthesis And Characterization, N. Konglom, C. Chuensangjun, C. Pechyen, S. Sirisansaneeyakul
Journal of Metals, Materials and Minerals
Poly-?-glutamic acid (?-PGA), one type of amino acid polymers, consists of D-and L-glutamic acids linked with amide bonding between ?-amino and ?-carboxylic acids. Naturally, ?-PGA could be biodegradable polymer and water-solubleapplied in various industries such as food, cosmetics, and pharmaceutical industries. Variation of initial L-glutamic acid concentration affecting on the production of ?-PGA by fermentation of Bacillus licheniformis was studied. The batch fermentation process consists of preparing the inoculum and expanding the culture of B. licheniformis into E medium (pH 6.5) for ?-PGA production. ?-PGA was recovered by using methanol precipitation together with lyophilization. For characterization, the molecular size of …
Cetirizine Dihydrochloride Tablets Comprising Two Different Lubricants With Highly Loaded Colloidal Silicon Dioxide,
2012
Chulalongkorn University
Cetirizine Dihydrochloride Tablets Comprising Two Different Lubricants With Highly Loaded Colloidal Silicon Dioxide, P. Katewongsa, T. Phaechamud
Journal of Metals, Materials and Minerals
Recently, the fast disintegrating tablet (FDT) has started gaining popularity and acceptance as new drug delivery system. Cetirizine dihydrochloride (CD) is the selective histamine (H-1)-receptor antagonist that is demonstrated to treat the symptoms associated with seasonal and perennial allergic rhinitis which this drug nowadays was prepared in form of FDT. Lubricant typically influences on tablet disintegration time (DT) and wetting time (WT). Therefore, it is important for optimizing the lubricant amount in this dosage form. The purpose of this study was to evaluate the effect of the lubricants (magnesium stearate (Mg-st) and sodium stearyl fumarate (SSF)) on the CD tablet …
Influence Of Casting Techniques On Hardness, Tarnish Behavior And Microstructure Of Ag-Cu-Zn-Si Sterling Silver Jewelry Alloys,
2012
Chulalongkorn University
Influence Of Casting Techniques On Hardness, Tarnish Behavior And Microstructure Of Ag-Cu-Zn-Si Sterling Silver Jewelry Alloys, C. Chanmuang, W. Kongmuang, J.T.H. Pearce, T. Chairuangsri
Journal of Metals, Materials and Minerals
The effects of Zn and Si on the hardness, tarnish resistance and microstructures of experimental Ag-Cu-Zn-Si alloy were investigated by means of vickers hardness, tarnish testing, optical and scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The various compositions of 935 sterling silver alloys produced by different casting techniques, investment (lost wax) process and metal mould casting, were compared. An induction casting machine with a vacuum system was used for investment casting at 1,025C with the mould temperature at 600C whereas a LPG/oxygen single flame tip torch was used for the metal mould process. Vickers hardness of the samples …
Ballistic Performance Of Ceramic/S2-Glass Composite Armor,
2012
Chulalongkorn University
Ballistic Performance Of Ceramic/S2-Glass Composite Armor, K. Dateraksa, K. Sujirote, R. Mccuiston, D. Atong
Journal of Metals, Materials and Minerals
Ceramic composite armor was initially developed during the Vietnam War for use as helicopter armor and personnel armor. The requirements for the armor were light weight and the capability to defeat small caliber armor piercing (AP) projectiles. Several different ceramics were developed and tested for this application. It was found that aluminum oxide (Al2O3), silicon carbide (SiC) and boron carbide (B4C) had the best combination of properties to meet the requirements. The long term goal of this research is to develop domestic knowledge, design and production capability of ceramic composite armors. In this present research, the relationship between the ballistic …
Bismuth Vanadate (Bivo4) Powder Prepared By The Sol-Gel Method,
2012
Chulalongkorn University
Bismuth Vanadate (Bivo4) Powder Prepared By The Sol-Gel Method, P. Pookmanee, S. Kojinok, S. Phanichphant
Journal of Metals, Materials and Minerals
Bismuth vanadate (BiVO4) powder was prepared by the sol-gel method. Bismuth nitrate and ammonium vanadate were used as the starting precursors with mole ratio of 1:1 in ethanol at 70C for 1 hour. The obtained sol was changed to the yellow gel after addition of deionized water and acetic acid. The yellow gel was dried at 100C for 48 h and calcined at 400-600C for 2 hours. The phase of BiVO4 powder was studied by X-ray diffraction (XRD). The morphology of BiVO4 powder was investigated by scanning electron microscopy (SEM). The element composition of BiVO4 powder was indicated by energy …
Effect Of Milling Method On The Particle Size Of Calcined 0.65pmn-0.35pt Powder,
2012
Chulalongkorn University
Effect Of Milling Method On The Particle Size Of Calcined 0.65pmn-0.35pt Powder, A. Boonruang, P. Ngernchuklin, C. Eamchotchawalit
Journal of Metals, Materials and Minerals
In this study, stoichiometric 0.65PMN-0.35PT powders have been prepared by columbite method. The perovskite single phase of PMN-PT was successfully synthesized after calcination of the mixed oxide at 900C/4hr. Due to the particle size of calcined powder has greatly effect on the electrical properties of sintered samples. Therefore, two different milling methods including high energy ball milling (HBM) and conventional ball milling (CBM) were used to grind the calcined powders. The results showed that the particle size distribution of calcined powders from HBM and CBM were 0.17 and 0.19 ?m, respectively. As a result, the relative density of the sintered …
Effect Of Zn Addition On Sol-Gel Derived Apatite/Wollastonite Glass-Ceramics Scaffolds,
2012
Chulalongkorn University
Effect Of Zn Addition On Sol-Gel Derived Apatite/Wollastonite Glass-Ceramics Scaffolds, S. Tubsungneon Rattanachan, N. Srakaew, R. Pethnin, N. Suppakarn
Journal of Metals, Materials and Minerals
Bioactive glasses and glass-ceramics consisting of CaO-MgO-P2O5-SiO2 system have been shown to be bioactive, resorbable and to exhibit appropriate mechanical properties for bone tissue engineering applications. Bioactive glass-ceramics scaffolds consisting of zinc doped-apatite/wollastonite (AW) glassceramics were prepared by coating polyurethane foams with sol-gel derived glass gels. Density and compressive strength of the scaffolds decreased with increased in zinc contents. In vitro bioactivity of Zndoped AW glass-ceramics in a simulated body fluid (SBF) showed the formation of apatite layer on the surface within 7 days of soaking. However, increasing Zn addition increased the chemical durability of the AW glass-ceramics, resulting in …
Characterization And Drug Behavior In Shellac Wax Poloxamer Matrix Tablets Fabricated With Mold Technique,
2012
Chulalongkorn University
Characterization And Drug Behavior In Shellac Wax Poloxamer Matrix Tablets Fabricated With Mold Technique, C. Choncheewa, T. Phaechamud
Journal of Metals, Materials and Minerals
Shellac wax is a waste product from shellac manufacturing process and has not been reported to be used as pharmaceutical matrix base. This study was to prepared and characterized shellac wax - poloxamer 407 matrix tablet comprising hydrophilic or hydrophobic drug which were prepared by molten technique. The ratios of poloxamer 407: shellac wax was varied and subsequently loaded with the different drug content before characterized with differential scaning calorimetry (DSC), thermogravimetric analysis (TGA) and powder x-ray diffractometry (PXRD). Drug release study was also performed for 25 mg drug loaded matrix tablet in distilled water using dissolution apparatus II at …
Role Of Aluminum Monostearate On Heat Treated-Chitosan Sponges Properties,
2012
Chulalongkorn University
Role Of Aluminum Monostearate On Heat Treated-Chitosan Sponges Properties, K. Yodkhum, T. Phaechamud
Journal of Metals, Materials and Minerals
Heat treatment can be employed to modify properties such as biocompatibility and degradation rate of chitosan-based materials. However, heat treatment generally has effect on worsening of physical properties of the biomaterials. Our previous study indicated that fatty additive; aluminum monostearate (Alst), could improve thermal stability of chitosan sponges. Aim of this study is to investigate an effect of amount of Alst on physicochemical properties of chitosan sponges treated by different heat treatment methods. Two methods of heat treatment including moist heat (autoclave at 121°C, 15 psi for 5 minutes) and dry heat (vacuum heat at 110°C for 24 hours) were …
Preparation And Characterization Of Highly Filled Graphite-Based Polybenzoxazine Composites,
2012
Chulalongkorn University
Preparation And Characterization Of Highly Filled Graphite-Based Polybenzoxazine Composites, A. Pengdam, S. Rimdusit
Journal of Metals, Materials and Minerals
This research aims to study suitable preparation methods and to characterize highly filled graphite composites using polybenzoxazine as a matrix. The high loading of graphite filler was attained in the range of 40 to 80% by wt. due to the very low a-stage viscosity of the benzoxazine resin (BA-a) used. The suitable condition for the compression molding of the highly filled graphite-polybenzoxazine (PBA-a) composites was at temperature of 200°C, and pressure of 15 MPa in the hydraulic hot-press machine for 3 hours to assure a fully cured specimen. The densities of the obtained composites were found to be in a …
Effect Of Silicon On Subcritical Heat Treatment Behavior And Wear Resistance Of 16 Wt% Cr Cast Iron With 2 Wt% Mo,
2012
Chulalongkorn University
Effect Of Silicon On Subcritical Heat Treatment Behavior And Wear Resistance Of 16 Wt% Cr Cast Iron With 2 Wt% Mo, P. Kosasu, S. Inthidech, P. Srichareonchai, Y. Matsubara
Journal of Metals, Materials and Minerals
Effects of Si content on the hardness, decomposition of austenite and abrasive wear resistance during subcritical heat treatment of hypoeutectic 16 wt% Cr -2 wt% Mo cast irons were investigated. The hypoeutectic 16 wt%Cr-2wt% Mo cast irons with 0.5-2.0 wt% Si were prepared. The as-cast specimens were heated up to subcritical temperatures at 50 K intervals from 673K for 14.4 ks ,28.8 ks and 43.2 ks and then, cooled to the room temperature by fan air cooling. In the as-cast state, the hardness increased gradually as Si content increased to 1.5 wt% and then decreased rapidly. The size and the …
Twin-Jet Electropolishing Of Cast Sterling Silver Alloys Using Perchloric Acid And Potassium Cyanide Solutions,
2012
Chulalongkorn University
Twin-Jet Electropolishing Of Cast Sterling Silver Alloys Using Perchloric Acid And Potassium Cyanide Solutions, W. Kongmuang, T. Chairuangsri, C. Chanmuang
Journal of Metals, Materials and Minerals
Twin-jet electropolishing of Ag-4.87 wt%Cu-0.79 wt%Zn-0.09 wt%Si alloy was studied. Two electrolytes, i.e. potassium cyanide solution in distilled water and glycerol-perchloric acid solution in absolute ethanol, were used in the experiments. Effects of parameters including voltage and electrolyte concentration have been studied. Surface of polishing specimens and artifact formed were characterized by light microscopy and electron microscopy. In general, the potassium cyanide solution is a better electrolyte than the glycerol-perchloric acid solution. A more uniform polishing can be obtained from the potassium cyanide solution at the voltage higher than 5 V. Increasing of the potassium cyanide concentration reduced the electrical …
Study Of Dynamic Vulcanized Pla/Enr Tpv Filled With Various Organic Modified Mmt (Ommt),
2012
Chulalongkorn University
Study Of Dynamic Vulcanized Pla/Enr Tpv Filled With Various Organic Modified Mmt (Ommt), C. Thongpin, N. Kuttanate, K. Kampuang, N. Suwanwanit
Journal of Metals, Materials and Minerals
In this research, we investigated the crystallization behavior of PLA and properties of PLA/ENR thermoplastic vulcanizates (TPVs). ENR was compounded with phenolic resin and with PLA at the blend ratio of 40/60 by using an internal mixer at 170°C and rotor speed of 70 rpm. Three types of organic modified montmorillonite (OMMT) which are Cloisite® 15A, Cloisite® 20 A and Cloisite® 30B were also added at various contents during mixing. The TPVs were pressed to form thin film in a compression molding machine and cooled down under pressure for 10 minutes. Crystallization behavior, thermal properties and morphology of TPVs were …
Preparation And Catalytic Property Of High Surface Area Mixed Oxides From Calcination Of Mgcucr- And Mgcual-Layered Double Hydroxides,
2012
Chulalongkorn University
Preparation And Catalytic Property Of High Surface Area Mixed Oxides From Calcination Of Mgcucr- And Mgcual-Layered Double Hydroxides, W. Trakarnpruk
Journal of Metals, Materials and Minerals
In this research work layered double hydroxides (LDHs) containing Mg, Cu and Cr(or Al) were prepared with starting Mg:Cu:Cr (or Al) molar ratio of 2:1:1. They were calcined at 500 ºC for 5 h to convert into corresponding mixed oxides possessing high surface area. The catalysts were characterized by chemical analysis (ICP), infrared spectroscopy (FTIR), thermal analysis (TGA/DTA), powder X-ray diffraction (XRD), surface area measurements and H2 temperature programmed reduction (TPR). Catalytic property of these mixed oxides catalysts were tested in the oxidation of ethylbenzene using tertbutylhydroperoxide as an oxidant without added solvent. The experimental results show that high conversion …
Phase Transformation In Ti-Mo-O,
2012
Clemson University
Phase Transformation In Ti-Mo-O, Herbert Boeckels
All Dissertations
The present dissertation has investigated the effect of oxygen on the ù and á phase stability in metastable Ti-Mo â titanium alloys using thermal analysis, hardness measurements, electron microscopy, and x-ray diffraction.
Single crystal x-ray diffraction has shown that oxygen atoms are located in the tetrahedral interstitial lattice sites in the rapidly cooled bcc Ti crystal structure, interfering directly with the reversible displacive formation of ù, with this transformation involving collapse of the bcc lattice along â. Subsequent thermal exposure of reversible ù, as occurring during slower cooling, heating, and aging, prompts short range diffusion and the formation of chemical …
Dynamic And Static Effects In Wetting Of Capillaries And Fibers,
2012
Clemson University
Dynamic And Static Effects In Wetting Of Capillaries And Fibers, Taras Andrukh
All Dissertations
This research is centered on the analysis of static and dynamic effects of wetting of single capillaries and fibers. We discuss specifics of the capillary rise and drop-on-fiber techniques and develop new methods of characterization of surface energy of single fibers when its contact angle varies between zero and ninety degrees. The contact angles were evaluated and compared for different substrates. We study the dynamics of the meniscus formation inside and outside of capillaries and fibers. We develop a mathematical model of liquid uptake by capillaries and analyze the factors affecting liquid uptake. The derived fundamental equation describes the dynamics …
Environmental And Biological Applications And Implications Of Soft And Condensed Nanomaterials,
2012
Clemson University
Environmental And Biological Applications And Implications Of Soft And Condensed Nanomaterials, Pengyu Chen
All Dissertations
Recent innovations and growth of nanotechnology have spurred exciting technological and commercial developments of nanomaterails. Their appealing physical and physicochemical properties offer great opportunities in biological and environmental applications, while in the meantime may compromise human health and environmental sustainability through either unintentional exposure or intentional discharge.
Accordingly, this dissertation exploits the physicochemical behavior of soft dendritic polymers for environmental remediation and condensed nano ZnO tetrapods for biological sensing (Chapter two-four), and further delineate the environmental implications of such nanomaterials using algae- the major constituent of the aquatic food chain-as a model system (Chapter five).
This dissertation is presented as …
Study Of Effect Of Temperature On The Synthesis Of Carbon Nanotubes By Floating Catalyst Method,
2012
Chulalongkorn University
Study Of Effect Of Temperature On The Synthesis Of Carbon Nanotubes By Floating Catalyst Method, R. Rajarao, B.R. Bhat
Journal of Metals, Materials and Minerals
Carbon nanotubes (CNTs) were grown by floating catalyst method using acetylene as carbon precursor and ferrocene as catalyst precursor. The CNTs were grown in the temperature range of 700 - 1150C. The prepared CNTs were purified by acid treatment and air oxidation methods. The purified CNTs were characterized by scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The purity of CNTs was determined by thermal analysis and X-ray diffraction method. The yield, diameter and length of grown CNTs were same at all temperatures. The crystalline perfection of CNTs increases as the temperature increases. Our results indicated that the synthesis …
The Effect Of Granule Morphology And Composition On The Compaction Behavior And Mechanical Properties Of 92% Alumina Spray Dried Granules,
2012
Chulalongkorn University
The Effect Of Granule Morphology And Composition On The Compaction Behavior And Mechanical Properties Of 92% Alumina Spray Dried Granules, K. Somton, K. Dateraksa, D. Atong, R. Mccuiston
Journal of Metals, Materials and Minerals
The compaction behavior and flexural strength of green compacts produced from four different types of 92% alumina spray dried granules were studied. Three of the granule types were produced in-house while the fourth is commercially-available. In addition, the decomposition behavior of the granules was studied by TGA in order to help explain the observed results. The morphology of the granules was observed using microscopy. Examination of the three granules produced in-house showed that they have several undesirable features; agglomeration, hollow granules and non-spherical granules. The morphology of the commercial granules showed them to be unagglomerated and spherical. The in-house granules …
