Materials Science and Engineering Commons^™

Chitosan And Trimethyl Chitosan Particles As Oral Vaccine Delivery Systems: Comparison Of The Potential To Initiate Immune Responses, S Boontha, H Ej Unginger, N Waranuch, A Polnok, T Pitaksuteepong

Journal of Metals, Materials and Minerals

In this study, particles having low MW (Chi-L), high MW (Chi-H) and their respective trimethyl chitosan (TMC) with a degree of quaternization (DQ) of about 40% (TMC-L-40 and TMC-H-40), and prepared by using chitosan, were used to compare their potentials for provoking immune responses to ovalbumin (OVA) following oral administration. The results showed that the Chi-L particles gave higher serum immunoglobulin G (IgG) responses to OVA than those induced with Chi-H, TMC-L-40 and TMC-H-40 particles. However, Chi-L and Chi-H particles gave similar secretory immunoglobulin A (sIgA) to OVA, and sIgA titers obtained from mice immunized with OVA-loaded TMC were negligible. …

Corrosion Prevention Of Rebar In Concrete Due To Chloride, Y Srimahajariyaphong, S Niltawach

Journal of Metals, Materials and Minerals

In coastal and brackish areas, black rebar in concrete structures suffers from chloride corrosion which leads to spalling of the concrete. The Half Cell Potential Measurement technique has been applied to study the corrosion behavior of both black and galvanized deformed rebar in different concretes. Additives in the concretes vary from pozzolan, calcium nitrite, to pozzolan plus calcium nitrite. Rebar which has higher half cell potential possesses better corrosion resistance. It has been found that concrete cover thickness has no significant effect on the half cell potential of either rebar; that for both types of rebar, the half cell potential …

Design And Construction Of Water Atomizer For Making Metal Powder, S Yenwiset, T Yenwiset

Journal of Metals, Materials and Minerals

Water Atomization for metal powder is an appropriate method for producing metal powder from different kinds of metal. Typically, a water atomizing machine is designed with a molten metal spraying chamber in a vertical or horizontal orientation depending on a nozzle design, a molten metal spraying chamber and related components. The main variables influencing the working condition of the water atomization process, which affect sizes, shapes and distribution of metal powder particles, are water pressure, water flow rate, a temperature higher than melting point of liquid metal and flow rate of liquid metal. The water atomizing machine in the study …

Applying Computer Simulation In Improving Heat Treating Condition Of Thin High-Carbon Steel Parts, T Korad, M Polboon, N Chumchery, J Pearce

Journal of Metals, Materials and Minerals

The study was carried out using COSMOSFlowWorks to predict heat treatment conditions for AISI 1085 high-carbon steel sheet that is used to produce automotive parts that require wear resistance and stiffness resulting from controlled moderately high hardness levels. To achieve such properties, flat high-carbon steel parts need to be hardened to produce acicular matrix structures, and the most suitable heat treatment process to harden thin parts without distortion is austempering. In producing hard and stiff thin section parts in this company study the austempering process was performed by soaking at 830C and then quenching in a NaCl salt bath at …

Self-Crack Closing Ability Of Mortar With Different Additives, D Jaroenratanapirom, R Sahamitmongkol

Journal of Metals, Materials and Minerals

Self-crack closing ability of cementitious materials has been studied in various aspects. However, most studies focus mainly on the cementitious material with only cement as a binder (without mineral additives), although many additives are commonly used at present. This research thus aims to investigate the effect of additives on this self-crack closing ability by observing and measuring crack width on the mortar specimens. Cracks were created on mortar specimens by splitting method at the age of 3 and 28 days. As most reports show that the best self-crack closing performance was achieved when a plenty of water was supplied, the …

Purification Of An Industrial Aluminum Alloy By Melt Stirring During Ohno Continuous Casting Process, S Fashu, L Jianguo, H Q. Dan

Journal of Metals, Materials and Minerals

With the purpose of upgrading the purity of a dilute industrial aluminum alloy during Ohno Continuous Casting (OCC) process through the use of forced melt stirring; the critical stirring intensity required under a casting speed of 2 mm/min was numerically determined. The determined critical stirring intensity induces convective velocity magnitudes into the melt which are effective in transporting solutes from the solute boundary layer into the bulk melt. It was found that, with adequate melt stirring, production of substantially long and high purity ingots during OCC is possible before their purity diminishes to lower than the initial alloy purity.

Effect Of Nitrogen Partial Pressure On Characteristic And Mechanical Properties Of Hard Coating Tialn Film, C Chokwatvikul, S Larpkiattaworn, S Surinphong, C Busabok, P Termsuksawad

Journal of Metals, Materials and Minerals

(Ti,Al)N coating has been serving for the industry as cutting and forming tools. Compared with TiN film, TiAlN film significantly increases tool lifetime. Therefore, it reduces machine downtime and increases productivity. In this work, (Ti,Al)N film was deposited on cold-work tool steel (SKD 11) using PVD cathodic arc system. The sintered Ti-Al target with composition of (at%) 50 Ti and 50 Al was used as a cathode. The deposition bias voltage, bias arc current and deposition time were set at 100 V, 70 A and 90 minutes, respectively. Nitrogen gas was purged into the system with the applied pressure of …

Modification Of Montmorillonite With A Cationic Softener For Finishing Cotton Fabric With Hand Builder Performance, S Kittinaovarat, N Jiratumnukul, N Koolpreechanan

Journal of Metals, Materials and Minerals

Montmorillonite (Mont) was modified by cationic exchange with the cationic softener TEGO 28 (Di-Palm carboxyethyl hydroxyethyl methyl ammonium methosulfate). XRD analysis suggested that intercalation occurred in the modified Mont (mMont). Softening finishing solutions composed of pure TEGO 28 with and without mMont were treated on cotton fabrics by the pad-dry method and then evaluated for stiffness, whiteness, tear strength and thermal stability. TEGO 28 treatment alone increased the stiffness property of the finished fabrics, and this was increased further by the co-inclusion of mMont at 3 and 5% (w/v), but higher or lower mMont concentrations led to a marked and …

Development Of Composition Modulated Multilayer Alloy Coatings And Their Corrosion Behavior, S Yogesha, A C. Hegde

Journal of Metals, Materials and Minerals

Multilayer Zn-Ni alloy coating was developed on mild steel from acid chloride bath containing thiamine hydrochloride, as additive. Composition modulated multilayer alloy (CMMA) coatings, or simply, multilayer coating with gradual change in composition were developed galvanostatically using triangular current pulses from single bath technique. CMMA coatings of Zn-Ni were developed under different conditions, such as cyclic cathode current densities (CCCDs) and a number of layers, and their corrosion behaviors were evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy method. Optimal configuration, (Zn-Ni)2.0/4.0/600 was found to exhibit ~50 times better corrosion resistance compared to monolayer (Zn-Ni)3.0 alloy, deposited from the same …

Effect Of Postweld Heat Treatment On Microstructures And Hardness Of Tig Weldment Between P22 And P91 Steels With Inconel 625 Filler Metal, N Tammasophon, W Homhrajai, G Lothongkum

Journal of Metals, Materials and Minerals

This research aims at searching for the optimal postweld heat treatment condition of the TIG weld joint between P22 (2.25Cr) and P91 (9Cr) steels using Inconel 625 as filler metal. The postweld heat treatment at 750C for 2, 4 and 6 hours was applied in order to reach the proper microstructure and hardness for high performance in mechanical properties at elevated temperatures. It is recommended that postweld heat treatment at 750C for 2 hours is the proper condition to reduce the hardness of heat affected zone (HAZ) of P91 steel.

Separation Of Lycopene/Solvent Mixture By Chitosan Membranes, P Yodjun, K Soontarapa, C Eamchotchawalit

Journal of Metals, Materials and Minerals

Acetone in view of lower toxicity could be used as extracting solvent of lycopene in tomato paste instead of hexane. The studied chitosan membranes were uncrosslinked and crosslinked types. It was found that the membrane morphology could be changed from porous to dense structure by increasing evaporation temperature or time or by crosslinking. They showed hydrophilicity but not preferred to both acetone and lycopene. The lycopene/acetone mixture could be separated by using water swollen chitosan membrane in pervaporation process. It was found that all studied membranes; i.e., both uncrosslinked and ionically crosslinked membranes prepared at 40 to 60C for 2 …

Chevron Crack Initiation In Mullti-Pass Drawing Of Inclusion Copper Shaped-Wire, S Norasethasopon

Journal of Metals, Materials and Minerals

In the copper superfine wire drawing, the internal cracks such as chevron cracks and breakage of the wire were fatal to the success of quantitative drawing operations. This paper shows how the main process parameters, the drawing pass numbers, influence the plastic deformation, hydrostatic stress, maximum principal tensile stress and chevron cracks initiation investigated by FEM simulation. The effect of the lateral and longitudinal sizes of a central cylindrical inclusion in the multi-pass copper shaped-wire drawing was studied. The plastic deformation, plastic strain, hydrostatic stress and maximum principal tensile stress of the copper shaped-wire containing an inclusion were obtained from …

Determination Of Forming Limit Stress Diagram For Formability Prediction Of Spce 270 Steel Sheet, S Panich, V Uthaisangsuk, J Juntaratin, S Suranuntchai

Journal of Metals, Materials and Minerals

The aim of this research is to apply numerical Finite Element Method (FEM) for determining Forming Limit Stress Diagram (FLSD) of sheet steel of grade SPCE 270. As a failure criterion for formability prediction in sheet metal forming process, the conventional Forming Limit Diagram (FLD) is often used. The FLD is a strain based criterion, by which the principal strains at failure are evaluated. Many investigations showed that the FLD is dependent on forming history and strain path. However, the stress based criterion does not confirm this dependency. This criterion is more robust against any changes in the strain path …

The Change Of Surface Alloy Compositions And Corrosion Behavior After Wedm Machining Of Commercially Pure Titanium (Grade 4) And Ti-6al-4v (Grade 5), K Sriprasertying, S Rhaiphu

Journal of Metals, Materials and Minerals

Nowadays, titanium and its alloys are widely used in medical applications because of excellent corrosion resistance and a high strength-to-weight ratio. Nevertheless, titanium and its alloys are classified as difficult-to-machine metals by conventional machining methods. Therefore, unconventional machining processes are recommended. Wire-electrical discharge machining (WEDM) has become an important non-traditional machining process, as it provides an effective solution for machining components made from difficult-to-machine metals. However, WEDM could damage the surface layer and have an effect on the biocompatibility properties. This research was focused on the effect of WEDM on grade 4 commercially pure titanium and Ti-6Al-4V (Grade 5) after …

Improving Quench Hardening Of Low Carbon Steel, T Korad, M Polboon, N Chumchery, J Pearce

Journal of Metals, Materials and Minerals

The carbon content in steel determines whether it can be directly hardened. If the carbon content is low (less than 0.25wt%) then an alternate means exists to increase the carbon content of the surface. In this study, the mixed quenchant consisting of brine and surfactants known as Superquench was applied in the quench-hardening process on AISI 1015 low carbon steel. The quench results were compared with quenching in heavy brine solution, water and oil which are recognized as the basic quenchants and cannot cause bulk-hardening low-carbon steels. The hardness tests on different points along the radius of cut round bar …

Study Conditions Of Aluminum Billets For Relationship Between Precipitated Phases And Homogenizing Temperature With Different Cooling Methods, U Phongsophitanan, M Polboon, N Chumchery

Journal of Metals, Materials and Minerals

In producing cast aluminum billets for using in extruded profile production, homogenization is one of the significant steps of the process. This project examined a suitable homogenizing temperature for usage in manufacturing besides common condition. Computerized fluid dynamics and image analysis solution were techniques to identify the relationship between the area fraction of precipitated phases and homogenizing temperature with different cooling methods. Temperature gradient pattern revealed that soaking temperatures at 575C and 565C are suitable conditions to be used in manufacturing. Furthermore, area fraction calculation showed that the area fractions of precipitated phases of each cooling method were not significantly …

Immobilization Of Lipase Onto Cyperus Papyrus L. For Biodiesel Production By Transesterification And Hydrolysis-Esterification, S Charuchinda, P Suthianthong, W Chulalaksananukul

Journal of Metals, Materials and Minerals

Lipase of Candida rugosa was immobilized on biomass support, plant fiber from Cyperus papyrus L., for biodiesel synthesis. The two immobilization techniques investigated in this study were physical adsorption and covalent binding with 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). Results showed that the prepared immobilized lipase by physical adsorption with adding heptane presented higher protein loading, lipase activity and degree of immobilization than that by physical adsorption in phosphate buffer solution and by covalent binding. This immobilized lipase was further applied as biocatalyst for biodiesel synthesis by transesterification and hydrolysis-esterification. The results showed that this immobilized lipase preferred to hydrolyze triglyceride in palm oil …

Improving The Efficiency Of Organic Solar Cells By Varying The Material Concentration In The Photoactive Layer, Kevin Anthony Latimer

Electrical & Computer Engineering Theses & Dissertations

Polymer-fullerene bulk heterojunction solar cells have been a rapidly improving technology over the past decade. To further improve the relatively low energy conversion efficiencies of these solar cells, several modifications need to be made to the overall device structure. Emerging technologies include cells that are fabricated with interfacial layers to facilitate charge transport, and tandem structures are being introduced to harness the absorption spectrum of polymers with varying bandgap energies.

When new structures are implemented, each layer of the cell must be optimized in order for the entire device to function efficiently. The most volatile layer of these devices is …

Ultrafast Electron Diffraction Study Of The Dynamics Of Antimony Thin Films And Nanoparticles, Mahmoud Abdel-Fattah

Electrical & Computer Engineering Theses & Dissertations

The ultrafast fast phenomena that take place following the application of a 120 fs laser pulse on 20 nm antimony thin films and 40 nm nanoparticles were studied using time-resolved electron diffraction. Samples are prepared by thermal evaporation, at small thickness (< 10 nm) antimony nanoparticles form while at larger thicknesses we get continuous thin films.

The samples are annealed and studied by static heating to determine their Debye temperatures, which were considerably less than the standard value. The thermal expansion under static heating also yielded the expansion coefficient of the sample material. Nanoparticle samples gave a very accurate thermal expansion coefficient (11 × 10^-6 K^-1).

Ultrafast time resolved electron diffraction …

Steel Angle Section Members Under Combined Axial Load And Unsymmetric Bending, Maheshchandra Rajasekharan Phanibhushan

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the outcome of an investigation into the experimental and theoretical behavior of steel angle section members under combined axial load and unsymmetric bending. Tests are conducted on a series of six angle section members provided with biaxial pinned-end boundaries about the cross-sectional non-principal axes. The end bending moments and axial load are applied in a quasi-static manner until the member load-carrying capacity is reached. The experimental load-deflection and load-strain curves are recorded. The theoretical analysis is based on a system of both elastic as well as materially nonlinear differential equations. The equations were solved using an iterative …

The Human Dimension Of Systemic Department-Level Change: A Change Agent’S Retrospective On A Case Of Reform, Linda Vanasupa

Materials Engineering

This paper represents a narrative of the process of department-level reform through the eyes of the initiating agent of change. Over the course of reform, our program has grown by 40%, primarily through retaining students. We exhibit a 10% net important rate of engineering students in the first two years of the curriculum relative to the college’s 5% mean export rate. Student freshmen SAT scores also indicate that we are attracting students with more balanced learning interests. The design of our Department Level Reform grant was to advance the knowledge of how to design engineering learning experiences that accomplish two …

Excitation-Induced Ge Quantum Dot Growth On Si(100)-2x1 By Pulsed Laser Deposition, Ali Oguz Er

Physics Theses & Dissertations

Self-assembled Ge quantum dots (QD) are grown on Si(100)-(2×1) with laser excitation during growth processes by pulsed laser deposition (PLD). In situ reflection-high energy electron diffraction (RHEED) and post-deposition atomic force microscopy (AFM) are used to study the growth dynamics and morphology of the QDs. A Q-switched Nd:YAG laser (λ = 1064 nm, 40 ns pulse width, 5 J/cm² fluence, and 10 Hz repetition rate) were used to ablate germanium and irradiate the silicon substrate. Ge QD formation on Si(100)-(2×1) with different substrate temperatures and excitation laser energy densities was studied. The excitation laser reduces the epitaxial growth temperature …

Computational Microstructure Modeling Of Asphalt Mixtures Subjected To Rate-Dependent Fracture, Francisco Aragao

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Computational microstructure models have been actively pursued by the pavement mechanics community as a promising and advantageous alternative to limited analytical and semi-empirical modeling approaches. The primary goal of this research is to develop a computational microstructure modeling framework that will eventually allow researchers and practitioners of the pavement mechanics community to evaluate the effects of constituents and mix design characteristics (some of the key factors directly affecting the quality of the pavement structures) on the mechanical responses of asphalt mixtures. To that end, the mixtures are modeled as heterogeneous materials with inelastic mechanical behavior. To account for the complex …

The Montana Mule: A Case Study In Interdisciplinary Capstone Design, Brock J. Lameres, Ahsan Mian, Hunter Lloyd, Robb Larson

Mechanical and Materials Engineering Faculty Publications

The Montana MULE: A Case Study in Interdisciplinary Capstone Design In May of 2010, NASA held the 1st annual Lunabotics Mining Competition at theKennedy Space Center in Florida. In this competition, 22 teams from across the nationbuilt remote-controlled, robotic excavators to mine lunar regolith simulant. The winnerof the competition was the team who could successfully deposit the most regolith into acollector in 15 minutes. The goal of this competition was to encourage multidisciplinarycapstone design projects. Of the 22 teams that participated in the competition, the“Montana MULE” from Montana State University (MSU) was the only robot tosuccessfully mine the qualifying weight …

Behavior Of Na+-Polystyrene Sulfonate At The Interface With Single-Walled Carbon Nanotubes (Swnts) And Its Implication To Swnt Suspension Stability, Tabbetha A. Dobbins, Richard Chevious, Yuri Lvov

College of Science & Mathematics Departmental Research

The assembly of sodium polystyrene sulfonate (Na+-PSS) at the surface of single-walled carbon nanotubes (SWNTs) in pH 3 aqueous solution is described. Rather than forming linear or sheet-like chain morphologies over SWNT surfaces, Na+-PSS adopts a spherically collapsed conformation believed to be the result of cation (either Na+ or H+) condensation onto the ionized polymer chain. It is well reported that cations (and also anions) adsorb preferentially onto single-walled and multi-walled carbon nanotube surfaces leading to an increased ion concentration in the near surface regions relative to the bulk solution. This work provides experimental evidence for preferentially absorbed cation condensation …

The Effects Of Damage Arrestment Devices In Composite Plate Sandwiches With Fastener Holes, Mark Anderson, Nancy Hung Choy, Lacey Jones, Rita Kourskaya

Aerospace Engineering

Composite materials such as a carbon fiber are used in a variety of new technologies including aircraft, spacecraft, and motor vehicles. Carbon fiber has a high strength to weight ratio, a key advantage over other material options. This report discusses the use of composite damage arrestment devices (DADs) in composite sandwich panels with a foam core. There are three different curing cycles tested for the DADs: pressure only, vacuum only, and vacuum with 1000 lbs of pressure. Using a Tetrahedron Heat Press to cure the composite specimen and an Instron Machine to perform tensile testing, data was collected for each …

A Comparison Of Two Headless Compression Screws For Operative Treatment Of Scaphoid Fractures, Ruby Grewal, Joseph Assini, David Sauder, Louis Ferreira, Jim Johnson, Kenneth Faber

Surgery Publications

PURPOSE: The purpose of this study was to compare the interfragmentary compression force across a simulated scaphoid fracture by two commonly used compression screw systems; the Acutrak 2 Standard and the 3.0 mm Synthes headless compression screw.

METHODS: Sixteen (8 pairs; 6 female, 2 male) cadaver scaphoids were randomly assigned to receive either the Acutrak 2 or Synthes screw with the contralateral scaphoid designated to receive the opposite. Guide wires were inserted under fluoroscopic control. Following transverse osteotomy, the distal and proximal fragments were placed on either side of a custom load cell, to measure interfragmentary compression. Screws were placed …

The Effects Of Cure Schedule On Properties Of Glass-Fiber Reinforced Epoxy Matrix Composites, Trevor J. Lee

Materials Engineering

Two different two-component resin systems were cured, via Differential Scanning Calorimetry, for the times recommended by their respective manufacturers. The resin cure schedules were designed to simulate typical and attainable processing conditions; they were cured at 120°F, 140°F, and 160°F, and in-mold post-cured at 200°F, 230°F, and 260°F. The resulting scans were then compared to a baseline cure for each resin system, consisting of two heating-cooling cycles at a constant rate of temperature change. These baseline cures were then used to determine the percent cure of each sample and the shift in glass transition temperature between the baseline cure and …

Final Design Review: Design Of An Integrated Solar Cell Array To Power A Solar Ear Hearing Aid Battery Recharger, Christina (Chrissa) Blattner, Scott Carey, Jared Myren, Faye Siao

Materials Engineering

As the energy of fossil fuel supplies are fast depleting due to high consumptions of energy by human beings, the need for other sources of energy, such as solar energy, has become a viable option. By creating solar cell arrays the desired voltage can be generated. The overall goal of the Solar Ear project is to create an array of photovoltaic cells connected with aluminum tracings to recharge batteries that are specifically used for hearing aids. The goal embodies two main areas: the design of a processing method to connect the cells during a micro-fabrication process and the creation of …

Process Refinement Through Design Of Experiments (Taguchi) To Reduce Porosity Levels Of Thin Flame Spray Nicrbsi Coatings On Cast Aluminium Alloys, David Culliton, David Kennedy, Tony Betts

Conference Papers

Thin(16matrix of key deposition parameters was constructed to develop the optimum spray parameters. The effects of parameter variations on the porosity levels of these coatings were assessed. Key parameter interactions were reported. Quantifiable interactions between the selected parameters were noted for the LM24 substrate. However, on the LM25 substrate these interactions were much less defined. Corrosion performance of the optimised coatings, based on electrochemical impedance spectroscopy, was reported. The presence of through-pores in the coatings were shown to reduce the corrosion resistance of the coated systems by a factor of 10, in dilute NaCl solutions, compared to bulk 316L stainless …