Sponsored Libre Research Agreements To Create Free And Open Source Software And Hardware,
2018
Michigan Technological University
Sponsored Libre Research Agreements To Create Free And Open Source Software And Hardware, Joshua M. Pearce
Michigan Tech Publications, Part 1
As a growing number of companies reject intellectual property (IP) monopoly-based business models to embrace libre product development of free and open source hardware and software, there is an urgent need to refurbish the instruments of university-corporate research partnerships. These partnerships generally use a proprietary standard research agreement (PSRA), which for historical reasons contains significant IP monopoly language and restrictions for both the company and the university. Such standard research agreements thus create an artificial barrier to innovation as both companies using a libre model and universities they wish to collaborate with must invest significantly to restructure the contracts. To …
Super Hydrophobicity Of Sputtered Ptfe Films On Nanotextured Aluminum Surface,
2018
Chulalongkorn University
Super Hydrophobicity Of Sputtered Ptfe Films On Nanotextured Aluminum Surface, S Lumjeak, T Lertvanithpo, P Limnonthakul, M Horprathum, P Songsirirtthigul
Journal of Metals, Materials and Minerals
In this research, the superhydrophobic surface was prepared by using the polytetrafluoroethylene (PTFE) thin films which deposited on aluminum (Al) nanotextures. The Al nanotextures have been prepared under different alkaline-treatment concentrations, and deposited with the PTFE thin films by the RF magnetron sputtering technique. During the alkaline treatments, the Al surface was immersed in the potassium hydroxide (KOH) solution with the concentrations of 1 mM to 0.10 mM. Then, the samples of PTFE films were deposited on Al nanotextures were characterized; the crystal structures, chemical compositions, physical morphologies, and surface roughness by photoelectron spectroscopy (PES), field-emission scanning electron microscopy (FE-SEM) …
Aluminium-Sic Composite: Study Of Its Mechanical Properties,
2018
Chulalongkorn University
Aluminium-Sic Composite: Study Of Its Mechanical Properties, D Sánchez-García, A Herrera-Vázquez, J Hinojosa-Torres
Journal of Metals, Materials and Minerals
Cylindrical specimens with geometries and sizes, in agreement with the standard of American Society for Testing Materials (ASTM), they were used to characterize the tension behaviour of the composite. A significant effect of the SiC shape/size on the tensile behaviour of aluminium-based composite was observed, caused by the differences between the superheat (993 K) and the mould temperatures (333 K, 473 K, 623 K) in the melting practice. Ultimate tensile stress and Fracture Toughness factor for the composite showed a numerical advantage over the corresponding ones to the aluminium at a solidification speed of 82.5 K·s-1. At the mould temperature …
A Comparative Study Of Nanofibrillated Cellulose And Microcrystalline Cellulose As Reinforcements In All-Cellulose Composites,
2018
Chulalongkorn University
A Comparative Study Of Nanofibrillated Cellulose And Microcrystalline Cellulose As Reinforcements In All-Cellulose Composites, S Tanpichai
Journal of Metals, Materials and Minerals
The reinforcing abilities of nanofibrillated cellulose (NFC) and microcrystalline cellulose (MCC) in composites were investigated and compared. All-cellulose composites were prepared using the dissolved MCC as the matrix, and NFC and MCC were introduced as the reinforcing phase. With the addition of MCC, tensile strength of the composites decreased; on the other hand, the higher tensile strength of the composites with NFC was found with increasing a NFC content. Strong interfacial interaction between the matrix and reinforcing phase could be obtained at a low content of the reinforcement was observed. At a higher content of the reinforcement the fiber pull-out …
Effect Of Tempering Temperature On Microstructure And Mechanical Properties Of Low Alloy Steel In Quenched Tempered Conditions,
2018
Chulalongkorn University
Effect Of Tempering Temperature On Microstructure And Mechanical Properties Of Low Alloy Steel In Quenched Tempered Conditions, V Yadav, A K. Singh, G Sahoo
Journal of Metals, Materials and Minerals
The effect of tempering temperature on the microstructure and mechanical properties of a low alloy steel has been investigated using optical microscopy, hardness testing and Charpy V-notch impact testing at -20°C, -40°C and -60°C. At first, the laboratory based study revealed that tempering the specimens at 650°C resulted in lowest hardness with highest impact energy. Based on this, the heat-treated industrial steel showed sufficiently high toughness after Charpy V-notch impact testing at -40°C. Fractography after impact testing showed predominately ductile dimple rupture in the sample tempered at 650°C. The presence of decomposed martesitic laths in prior austenite was noticed in …
Wear Properties Of Boron Added High Strength Low Alloy (Hsla) Sae 8620 Steel,
2018
Chulalongkorn University
Wear Properties Of Boron Added High Strength Low Alloy (Hsla) Sae 8620 Steel, M Musa, A G. Mohammed, A Muhammad
Journal of Metals, Materials and Minerals
The High Strength Low Alloy (HSLA) SAE 8620 steel with different contents of boron in ppm rate used in bearings, automotive gearing and automotive body components applications were studied. We report the relationship between wear properties, microstructural characterization and hardness properties of the steel. The steel chemical composition is selected to obtain relatively high mechanical properties with different boron contents. Increasing the normalization temperature and boron content, shows ferrite grain-size becomes larger when compared to lower normalization temperatures and boron content. With differences in boron content, only 2 HBN were measured from the average hardness of 3.3 ppm and 13.5 …
Crystalline Silica In Compressed Rice Hull Coke Ash,
2018
Chulalongkorn University
Crystalline Silica In Compressed Rice Hull Coke Ash, T Okutani, E Ichikawa, H Nagai, T Hashimoto, T Makihata
Journal of Metals, Materials and Minerals
Compressed rice hull coke was produced by compressing rice hulls ground to less than 200 µm diameter at 1.22x106 N/m2 and 310˚C with an oxygen deficient atmosphere. The compressed rice hull coke had a 5 cm outer diameter, a 1.5 cm inner diameter and 35 cm length. The density of the coke is 1.2, and, the heat value is 16570 kJ·kg-1. In this study, 2 kg coke was combusted at the average temperature of 850˚C for 104 min with a maximum temperature of 860˚C. The ash was colored black-grey, and the form remained coke. The ash contained 95.4% silica with …
Investigation Of Erosive Wear Behaviour Of Tungsten Carbide Cobalt Coated Metal Matrix Composites Using Ann,
2018
Chulalongkorn University
Investigation Of Erosive Wear Behaviour Of Tungsten Carbide Cobalt Coated Metal Matrix Composites Using Ann, M Pasha, M Kaleemulla
Journal of Metals, Materials and Minerals
An artificial neural network (ANN) model was employed on erosive wear result of aluminium 7034 T6 reinforced with different weight percentage of Al2O3 and SiC with tungsten carbide cobalt (WC-Co) coated composites. WC-Co in the form of powder was pretreated before coating, to identify the inflence of pretreatment on the substrate. The WC-Co coating was deposited with high velocity oxy fuel (HVOF) sparay method. The microstructural examination was carried through scanning electron microscope (SEM) and to identify the elemental composition of coated specimens, energy dispersive X-ray analysis (EDX) was used. These material charecterisation shows that pretreated WC-Co coated Al 7034 …
Starch Consolidation Of Porous Fused Silica Ceramics,
2018
Chulalongkorn University
Starch Consolidation Of Porous Fused Silica Ceramics, K Kanlai, T Wasanapiarnpong, B Wiratphinthu, K Serivalsatit
Journal of Metals, Materials and Minerals
Starch consolidation is a forming technique, in which ceramic suspension is consolidated by gelatinization of starch under suitable temperature. This technique is promising for fabricating porous ceramics because starch can act as a binder as well as a pore former. In this study, porous fused silica ceramics were prepared by starch consolidation using glutinous rice flour as a gelling agent. The 29 vol% solid loading of fused silica slurries with the addition of glutinous rice flour were prepared. After mixing the slurries were poured into a plastic mold and kept in an oven at 75ºC for an hour. The green …
Carboxymethylchitosan-Based Hydrogels Crosslinked With Polydimethylsiloxane,
2018
Chulalongkorn University
Carboxymethylchitosan-Based Hydrogels Crosslinked With Polydimethylsiloxane, N Rodkate, N Deepuppha, B Rutnakornpituk, M Rutnakornpituk
Journal of Metals, Materials and Minerals
Synthesis and properties of hydrophilic carboxymethylchitosan (CMC) hydrogels containing hydrophobic polydimethylsiloxane (PDMS) were herein presented. Fourier transform infrared spectroscopy indicated that PDMS can covalently bound to CMC chains with the use of hexamethylene-1,6-di-(aminocarboxysulfonate) (HDA), a water soluble crosslinker. Also, according to scanning electron microscopy, PDMS microphases with the size of 0.2-0.5 µm in diameter were thoroughly dispersed in CMC matrix. Addition of PDMS improved properties of the CMC hydrogels including increasing water vapor permeability and water swellability, improving tensile properties and increasing surface hydrophobicity. PDMS with different amounts (1-20 wt%) and molecular weights (2,000 and 8,000 g·mol-1) were added into …
Simple And Rapid Preparation Of Cuo Film Using Silar Process For Application As Hole-Transporting Layer In P-I-N Perovskite Solar Cell,
2018
Chulalongkorn University
Simple And Rapid Preparation Of Cuo Film Using Silar Process For Application As Hole-Transporting Layer In P-I-N Perovskite Solar Cell, S Wongrerkdee, K Hongsith, S Choopun, K Lohawet, P Kumno
Journal of Metals, Materials and Minerals
Copper oxide (CuO) films are considered to be an alternative metal oxide semiconductor for hole-transporting layer application in p-i-n perovskite solar cells due to their unique properties including intrinsic p-type materials and energy band level matching. The films can be synthesized using several methods such as sputtering, solution process and spin-coating processes. However, using the successive ionic layer adsorption and reaction (SILAR) process to prepare a CuO hole-transporting layer in p-i-n perovskite solar cells is still underreported. Thus, this study prepared the SILAR processed CuO films and applied as a hole-transporting layer in p-i-n perovskite solar cells. The results showed …
Influence Of Blt Content On Phase Structure And Electrical Properties Of (1-X)Bt-Xblt Ceramic,
2018
Chulalongkorn University
Influence Of Blt Content On Phase Structure And Electrical Properties Of (1-X)Bt-Xblt Ceramic, N Thongmee, R Sumang, S Pojprapai, T Klaytae
Journal of Metals, Materials and Minerals
(1-x)BaTiO3-x(Bi3.25La0.75)Ti3O12; (1-x)BT-xBLT ceramics with x = 0-0.20 wt.% were prepared by a solid-state reaction method. The BaTiO3 (BT) and (Bi3.25La0.75)Ti3O12 (BLT) powders were, respectively, calcined at 1100°C and 750°C for 4 h. The (1-x)BT-xBLT samples were sintered between 1250°C and 1350°C. The structure exhibited a transformation from tetragonal to orthorhombic with increasing in BLT contents. The average grain size increased with increasing BLT contents. The maximum density and relative density about 6.19 ± 0.07 g/cm3and 99.3% were obtained for the composition of 0.95BT-0.05BLT. The Curie temperature (Tc) continuously decreased with increase in BLT contents. The dielectric constant showed a broad …
Eggshell Waste: An Effective Source Of Hydroxyapatite For Photocatalyst,
2018
Chulalongkorn University
Eggshell Waste: An Effective Source Of Hydroxyapatite For Photocatalyst, S Ummartyotin, H Manuspiya
Journal of Metals, Materials and Minerals
Interest in eggshell waste and its modification has been increasing rapidly. The outstanding property of eggshell waste is its high calcium carbonate content. This can be transformed to calcium oxide, and can provide a source of hydroxyapatite. As interest in clean technology has grown, the use of eggshell waste has become a focus of research. The objective of this review article is to characterize eggshell waste, describe the preparation of hydroxyapatite from eggshell waste and its modification, and discuss the use of hydroxyapatite as a photocatalyst.
Recent Developments In The Field Of Metal Foam-Polymer Hybrid Materials: A Brief Overview,
2018
Chulalongkorn University
Recent Developments In The Field Of Metal Foam-Polymer Hybrid Materials: A Brief Overview, A Chaturvedi
Journal of Metals, Materials and Minerals
In this paper, a brief overview of the various techniques employed for the preparation of metal foam-polymer hybrid/composite materials including infiltration/penetration and adhesive joining is given. Scanning electron microscopy (SEM) micro structural characterization method and various dependent mechanical properties such as stress-strain diagram, energy absorption etc is described. In addition, some possible applications of such materials are discussed. The paper intends to inform as well as educate the reader about the various aspects of this emerging field in a lucid manner.
Repeated Loading Model For Elastic-Plastic Contact Of Geomaterial,
2018
Missouri University of Science and Technology
Repeated Loading Model For Elastic-Plastic Contact Of Geomaterial, Jian Wang, Qimin Li, Changwei Yang, Caizhi Zhou
Materials Science and Engineering Faculty Research & Creative Works
A new nonlinear hysteretic model with considering the loading, unloading, and reloading processes is developed based on Drucker—Prager yield criterion and finite-element analysis. This model can be used for multiple repeated elastic—plastic normal direction contact problems between two identical spherical geomaterials. After examining the influence of material properties, strain hardening, and loading histories, we found that the hysteretic phenomena (represented by residual displacement and plastic work) become weak after the first cycle, and the subsequent cycles step into elastic shakedown state eventually. A critical number of cycles can be used to estimate the state of ratchetting, plastic shakedown, as well …
The Yielding Transition In Periodically Sheared Binary Glasses At Finite Temperature,
2018
Wright State University - Main Campus
The Yielding Transition In Periodically Sheared Binary Glasses At Finite Temperature, Nikolai V. Priezjev
Mechanical and Materials Engineering Faculty Publications
Non-equilibrium molecular dynamics simulations are performed to investigate the dynamic behavior of three-dimensional binary glasses prepared via an instantaneous quench across the glass transition. We found that with increasing strain amplitude up to a critical value, the potential energy approaches lower minima in steady state, whereas the amplitude of shear stress oscillations becomes larger. Below the yielding transition, the storage modulus dominates the mechanical response, and the gradual decay of the potential energy over consecutive cycles is accompanied by reduction in size of transient clusters of atoms with large nonaffine displacements. In contrast, above the yield strain, the loss modulus …
Enhanced Coupling Strength Gratings For Outcouplers In Optical Waveguides,
2018
Southern Methodist University
Enhanced Coupling Strength Gratings For Outcouplers In Optical Waveguides, Ruo-Hua He
Electrical Engineering Theses and Dissertations
Gratings used for silicon photonic waveguides were demonstrated with outcoupling efficiency greater than 60% in a short grating length of 13 µm at a wavelength of 1550 nm. Due to problems of generating light from silicon, light has to be generated by either growing III-V material, wafer bonding III-V material to silicon, or externally generated light has to be coupled into and out of silicon photonic waveguides. Gratings have been used in semiconductor lasers to obtain single frequency operation. Some applications such as telecommunications require a narrow and single spectral line. And such single frequency lasers are typically distributed Bragg …
Atomic Diffusion In The Feal Alloy: A Research Via The Kinetic Monte Carlo Method,
2018
Chulalongkorn University
Atomic Diffusion In The Feal Alloy: A Research Via The Kinetic Monte Carlo Method, E V Manrique Castillo, F A. Reyes Navarro
Journal of Metals, Materials and Minerals
For a binary alloy with an ordered structure B2, we research the atomic migration by means of kinetic Monte Carlo simulations, where the atomic migration results from the exchange of positions between an atom and a vacancy in a rigid lattice. The atomistic kinetic model we used is based on the jump rate theory and the residence time algorithm, wherein we consider the pair interactions between neighbours up to the next-nearest neighbours. Likewise, we determine the ratio of the diffusion coefficients as a function of temperature and investigate the antiphase boundary mobility in the last stages of the ordering process. …
Synthesis Of Nanoparticulate Ti-Doped Zno By Solution Combustion Technique,
2018
Chulalongkorn University
Synthesis Of Nanoparticulate Ti-Doped Zno By Solution Combustion Technique, O Jongprateep, P Deedit, R Puranasamriddhi, K Meesombad
Journal of Metals, Materials and Minerals
ZnO and TiO2 have been widely accepted as prominent photocatalysts. Enhancement of their photocatalytic activities can be achieved through particle refinement and doping. Solution combustion technique is a simple and cost-effective method capable of producing fine ceramic powders with homogeneous chemical compositions. It is, therefore, employed in this research project as the technique to synthesize nanometer-sized Ti-doped ZnO powders. The research also aimed at examining a relationship among doping contents, chemical composition, particle sizes, and photocatalytic performance of the synthesized powder. Compositional analysis revealed that the solubility limit of Ti in zinc oxide was within the range of 3 at% …
Enhancement Of Mechanical, Thermal And Antibacterial Properties Of Sisal/Phbv Biocomposite By Fibre Modification,
2018
Chulalongkorn University
Enhancement Of Mechanical, Thermal And Antibacterial Properties Of Sisal/Phbv Biocomposite By Fibre Modification, T Kittikorn, R Malakul, E Stromberg, M Ek, S Karlsson
Journal of Metals, Materials and Minerals
Lignocellulosic biocomposite is a promising biodegradable materials, though improvement of the interfacial adhesion between cellulose fibre and polymer matrix is still challenged. Therefore, this work investigated the effect of propionylation of sisal reinforced fibre in the sisal/polyhydroxybutyrate-co-valerate (PHBV) biocomposite. Propionylation involved esterification substitution of propionic anhydride to hydroxyl group of sisal fibre, where ester group (COOR) of propionylated fibre was successfully observed by Fourier transform Infrared spectroscopy (FTIR). Then mechanical and thermal properties were evaluated and biodegradation characteristics were assessed. The tensile strength and modulus of propionylated sisal/PHBV biocomposite were greater than unmodified sisal/PHBV, which revealed better compatibility at the …
