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Articles 3211 - 3240 of 3414

Full-Text Articles in Engineering

Characterization And Drug Behavior In Shellac Wax Poloxamer Matrix Tablets Fabricated With Mold Technique, C. Choncheewa, T. Phaechamud Dec 2012

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 …

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Twin-Jet Electropolishing Of Cast Sterling Silver Alloys Using Perchloric Acid And Potassium Cyanide Solutions, W. Kongmuang, T. Chairuangsri, C. Chanmuang Dec 2012

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 …

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Fabrication And Characterization Of Heterojunction For Cds Thin Films And Cualo2 Ceramic Pill Substrate, T. Gaewdang, N. Wongcharoen, A. Nopparuchikun, T. Wongcharoen, C. Poo-Rakkiat Dec 2012

Fabrication And Characterization Of Heterojunction For Cds Thin Films And Cualo2 Ceramic Pill Substrate, T. Gaewdang, N. Wongcharoen, A. Nopparuchikun, T. Wongcharoen, C. Poo-Rakkiat

Journal of Metals, Materials and Minerals

In this research paper, CdS thin films were deposited by thermal evaporation in vacuum on CuAlO2 ceramic pill substrate. From the data of I-V measurements at low temperature (20-300 K) the junction barrier height, ideality factor and series resistance values can be evaluated by using thermionic emission (TE) theory and Cheung's method. The junction barrier height and ideality factor were found to be strong temperature dependence. Evaluation of forward I-V data reveals a decrease in the zero-bias barrier height, but an increase in the ideality factor with decrease in temperature. In part of C-V measurements at room temperature, the obtained …

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Study Of Effect Of Temperature On The Synthesis Of Carbon Nanotubes By Floating Catalyst Method, R. Rajarao, B.R. Bhat Dec 2012

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 …

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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 Dec 2012

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 …

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Preparation And Catalytic Property Of High Surface Area Mixed Oxides From Calcination Of Mgcucr- And Mgcual-Layered Double Hydroxides, W. Trakarnpruk Dec 2012

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 …

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Electrochemically Enhanced Plasticity Of Steels, Y.B. Unigovski, E.M. Gutman, Z. Koren, B. Borohov Dec 2012

Electrochemically Enhanced Plasticity Of Steels, Y.B. Unigovski, E.M. Gutman, Z. Koren, B. Borohov

Journal of Metals, Materials and Minerals

It is known that electrochemical surface treatment can decrease the residual stresses and the hardness of the surface layer as a result of the chemomechanical effect (CME), and also to improve the ability to plastic deformation, e.g., deep drawing for high strength alloys. The present research is aimed at using CME in order to improve such technological processes as rolling, deep drawing and other processes requiring an increase in the ductility of the metal surface layer using the hardness test assisted by electrochemical polarization. The hardness measurements were carried out using a microhardness tester equipped with a special three-electrode electrochemical …

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Nr/Xsbr Nanocomposites With Carbon Black And Carbon Nanotube Prepared By Latex Compounding, A. Boonmahitthisud, S. Chuayjuljit Jul 2012

Nr/Xsbr Nanocomposites With Carbon Black And Carbon Nanotube Prepared By Latex Compounding, A. Boonmahitthisud, S. Chuayjuljit

Journal of Metals, Materials and Minerals

Two series of natural rubber/carboxylated styrene butadiene rubber (NR/XSBR) (80/20) nanocomposites containing different loadings of carbon black (CB) (3-9 phr) and carbon nanotube (CNT) (0.1-0.4 phr) have been prepared by a latex stage compounding method. Before mixing with NR/XSBR blended latex, CB and CNT were dispersed and stabilized in water by ball milling with the aid of surfactant. The obtained compounded latex was cast into sheet on a glass mold and thereafter cured in an oven at 80°C for 3 h. The tensile properties (tensile strength, modulus at 300% strain, elongation at break), dynamic mechanical properties (loss tangent, storage modulus) …

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Low-Cycle Fatigue Of Thermally-Cycled Carbon-Epoxy Composite, Ya. B. Unigovski, A. Grinberg, E. M. Gutman, R. Shneck Jul 2012

Low-Cycle Fatigue Of Thermally-Cycled Carbon-Epoxy Composite, Ya. B. Unigovski, A. Grinberg, E. M. Gutman, R. Shneck

Journal of Metals, Materials and Minerals

Investigation of low-cycle fatigue of composites is of vital importance for the design of structural components. In this study, the effects of thermal cycling on low-cycle fatigue behavior of carbon-epoxy laminate are investigated in a purely bending mode at strain ratios of -1 and 0.1. It is found that a very small increase in the plastic strain amplitude catastrophically shortens the fatigue life N of the composite determined as a number of cycles corresponding to 0.9 of the initial force. The preliminary thermal cycling of the composite at the temperature varied from 180°C to −195.8°C shortens N values in comparison …

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Failure Analysis Of Bearings In Air Conditioning Compressor, P. Promdirek, A. Leidig, T. Keawjarus, P. Tong-In Jul 2012

Failure Analysis Of Bearings In Air Conditioning Compressor, P. Promdirek, A. Leidig, T. Keawjarus, P. Tong-In

Journal of Metals, Materials and Minerals

Two journal bearings of a compressor were failed in service. The wear which led to crack was observed at the internal surface of both bearings. The objective of this analysis is to evaluate the reason for the wear found on the internal bearings surface. Two bearings were returned from field and others in several conditions were examined. Electron probe micro analyzer and microhardness was used for metallurgical analysis. It revealed that bearing consisted of two different layers: 1) Fe-base and 2) Al-Sn alloy. Surface worn at the internal surface which composed of Al-Sn alloy was found. The results also showed …

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Corrosion Assessment Of Cast Aluminum Parts In Ethanol Fuel Blends, P. Wirot, J. Troset, W. Khonraeng, S. Mahabunphachai, E. Viyanit Jul 2012

Corrosion Assessment Of Cast Aluminum Parts In Ethanol Fuel Blends, P. Wirot, J. Troset, W. Khonraeng, S. Mahabunphachai, E. Viyanit

Journal of Metals, Materials and Minerals

Nowadays, the use of ethanol fuel blends in automobiles has become more and more worldwide since the ethanol mixture would enhance the performance of the engine and fuel economy ($/mile), while reducing the hazardous exhaust released to the environment. However, the use of ethanol fuel blends may induce some material compatibility issues on some automotive parts that were not designed to be used in contact with ethanol. In other words, the humidity in the ethanol would cause corrosion problem on these parts. The goal of this study is to assess the corrosion value of two cast aluminum parts in a …

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Extraction Of Tin From Hardhead By Oxidation And Fusion With Sodium Hydroxide, C Bunnakkha, C Jarupisitthorn Jul 2012

Extraction Of Tin From Hardhead By Oxidation And Fusion With Sodium Hydroxide, C Bunnakkha, C Jarupisitthorn

Journal of Metals, Materials and Minerals

In this research work, the extraction of tin from tin-iron alloy or hardhead which is the intermediate product obtained during tin smelting was investigated. The hardhead containing 32.40 wt% Sn and 45.81 wt% Fe was ground to different sizes and oxidized at 500 to 800 °C for 1 to 6 hours to form SnO2 and Fe2O3. The results indicated that an increase in oxidation temperature decreased the required oxidation time. However using too high oxidation temperature (800 °C) resulted in sintering of the oxide product.In sodium hydroxide fusion stage, effects of fusion temperature, fusion time, NaOH quantity and oxide product …

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Tribological Behavior Of Austenitic Stainless Steel And Vanadium Carbide Coated By Trd Process, C. Lertlummeechai, P. Sricharoenchai Jul 2012

Tribological Behavior Of Austenitic Stainless Steel And Vanadium Carbide Coated By Trd Process, C. Lertlummeechai, P. Sricharoenchai

Journal of Metals, Materials and Minerals

In forming austenitic stainless steel sheet, galling is the major cause of tool steels failure. Coating on tool surface is an effective way to lessen galling tendency. In this paper, vanadium carbide coating by TRD process was conducted on tool steel and intentionally tempered in air to produce thicker vanadium oxide on vanadium carbide surface. Ring-on-disc wear test was conducted by sliding with austenitic stainless steel ring to investigate tribological behavior. Weight of ring was measured before and after wear tests. Chemical composition of ring surface was crosssection analyzed by EPMA. Surface of the disc was analyzed by XPS. Wear …

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Preparation Of Organosilane Treated Microcrystalline (Simcc) And Simcc/Polypropylene Composites, P. Thummanukitcharoen, S. Limpanart, K. Srikulkit Jul 2012

Preparation Of Organosilane Treated Microcrystalline (Simcc) And Simcc/Polypropylene Composites, P. Thummanukitcharoen, S. Limpanart, K. Srikulkit

Journal of Metals, Materials and Minerals

In this study, the silane treated microcrystalline cellulose (SiMCC)/polypropylene composite was prepared. In the first step, the surface modification of microcrystalline cellulose (MCC) with various concentrations of hexadecyltrimethoxysilane was carried-out in order to obtain the SiMCC having good compatibility with PP matrix. Characterizations including SEM, FT-IR, TGA and DSC were employed to analyze the structure of SiMCC. SEM revealed that MCC surface morphology was changed from rod shape into rough particles after silane treatment. In the next step, the obtained SiMCC was mixed with PP powder using twin-screw extruder. Based on TGA results, it was found that the addition of …

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Three-Body-Type Abrasive Wear Behavior Of 26% Cr Cast Iron With Molybdenum, A. Chooprajong, P. Sricharoenchai, S. Inthidech, Y. Matsubara Jul 2012

Three-Body-Type Abrasive Wear Behavior Of 26% Cr Cast Iron With Molybdenum, A. Chooprajong, P. Sricharoenchai, S. Inthidech, Y. Matsubara

Journal of Metals, Materials and Minerals

Hypoeutectic 26 wt% Cr cast irons without and with Mo were prepared in order to investigate their abrasion wear resistance. The annealed specimens were hardened from 1323 K (As-H) and then tempered at three levels of temperatures between 673 and 823 K for 7.2ks, the temperature giving the maximum hardness (HTmax), lower temperature than that at HTmax (L-HTmax ) and higher temperature than that at HTmax (H-HTmax). The abrasive wear resistance was evaluated using Rubber Wheel abrasion test (three-body-type). It was found that hardness and volume fraction of retained austenite (V) in the heat-treated specimens varied with the Mo content …

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The Oxidation Behaviour Of Stainless Steel Aisi 409 Coated By Decorative Nickel-Chromium Plating, T. Wongpinij, T. U-Dom, T. Suptrakun, T. Puttanasun, C. Pimpan, N. Nangnoi, P. Wongpanya Jul 2012

The Oxidation Behaviour Of Stainless Steel Aisi 409 Coated By Decorative Nickel-Chromium Plating, T. Wongpinij, T. U-Dom, T. Suptrakun, T. Puttanasun, C. Pimpan, N. Nangnoi, P. Wongpanya

Journal of Metals, Materials and Minerals

The continuous and cyclic oxidation behaviour of ferritic stainless steel AISI 409 surfacecoated by decorative nickel-chromium plating was studied. Firstly, the plated AISI 409 steel samples were cut into rectangular pieces of 20x10x3 mm. Nickel plating was electroplated with various times, i.e., 0, 5, 10 and 15 minutes; subsequently the decorative chromium plating was performed for 5 minutes. Then, the samples were exposed to 200ºC and 300ºC. The degradation of samples was evaluated by considering weight alteration after oxidation test. The oxidation product and surface of samples were characterized by optical microscope and scanning electron microscope (SEM) with energy dispersive …

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A Micromechanical Flow Curve Model For Dual Phase Steels, S. Sodjit, V. Uthaisangsuk Jul 2012

A Micromechanical Flow Curve Model For Dual Phase Steels, S. Sodjit, V. Uthaisangsuk

Journal of Metals, Materials and Minerals

In the automotive industries, Dual Phase (DP) steels have become a favoured material for the car body parts due to their excellent combination of high strength and good formability. A microstructure of DP steel generally consists of a matrix of ferrite reinforced by small islands of martensite. Experimental investigations showed that effects of martensite phase fraction, morphology, and phase distribution play an important role for the mechanical and fracture behaviours of the dual phase steel. In the present work, an approach concerning FE based modelling for predicting flow curve of DP steels has been introduced using a Representative Volume Element …

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Porous Niti Produced By Nitita Transient-Liquid-Assisted Method, O. Worasub, A. Bansiddhi Jul 2012

Porous Niti Produced By Nitita Transient-Liquid-Assisted Method, O. Worasub, A. Bansiddhi

Journal of Metals, Materials and Minerals

This work presents a novel method for preparing porous NiTi by powder metallurgy using a vacuum sintering technique. Tantalum was used as a transient liquid phase creator, which enhanced the sinterability of NiTi powders. The effect of Ta content and powder packing on the degree of densification were investigated. The porous NiTi exhibited shape memory behavior and a large recovery strain, analyzed by differential scanning calorimetry and compressive testing, respectively, making the material promising for bone implant applications. In addition, macroporosity was created by using NaCl spaceholders. Adding 3 atomic percent of Ta and 60 volume percent NaCl space-holder resulted …

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Corrosion Behavior Of Aisi 4140 Steel Surface Coated By Physical Vapor Deposition, C. Keawhan, P. Wongpanya, N. Witit-Anun, P. Songsiriritthigul Jul 2012

Corrosion Behavior Of Aisi 4140 Steel Surface Coated By Physical Vapor Deposition, C. Keawhan, P. Wongpanya, N. Witit-Anun, P. Songsiriritthigul

Journal of Metals, Materials and Minerals

The corrosion behavior of uncoated and CrN-coated onto AISI 4140 steel was studied by electrochemical technique. Firstly, the AISI 4140 steel samples were solution heat treated and oil quenched in order to achieve proper hardness. Then, they were surface-prepared with alteration of surface roughness by using SiC paper at different numbers of 180, 600, and 1200 prior to CrN coating. The samples were coated with CrN film by physical vapor deposition (PVD) technique. The corrosion behavior of the uncoated and CrN-coated samples was studied in air-saturated 3.5 wt% NaCl solution at the pH values of 2, 7 and 10 at …

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Effect Of Vanadium On Subcritical Heat Treatment Behavior Of Hypoeutectic 16 Wt% Cr Cast Iron Containing 2 Wt% Mo, R Junsamoot, S Inthidech, K Sriprateep, P Sricharoenchai, Y Matsubara Dec 2011

Effect Of Vanadium On Subcritical Heat Treatment Behavior Of Hypoeutectic 16 Wt% Cr Cast Iron Containing 2 Wt% Mo, R Junsamoot, S Inthidech, K Sriprateep, P Sricharoenchai, Y Matsubara

Journal of Metals, Materials and Minerals

Subcritical heat treatment of austenite in alloyed cast iron by tempering at the temperature below pearlite transformation (A1), has been used to improve matrix hardness without hardening. Hypoeutectic high chromium cast irons containing 16 wt% Cr - 2 wt% Mo without and with V were prepared in order to clarify the effect of holding temperature and holding time on behavior of hardness and decomposition fraction of austenite in matrix (f) in subcritical heat treatment. As-cast specimens were held at temperature from 723 K to 923 K for 14.4 - 43.2 ks, and then cooled by fan air. In the as-cast …

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Recovery Of Zinc From The Spent Zinc-Carbon Dry Cell Batteries Through Pyrometallurgical Route, M Haque Khan, Asw Kurny Dec 2011

Recovery Of Zinc From The Spent Zinc-Carbon Dry Cell Batteries Through Pyrometallurgical Route, M Haque Khan, Asw Kurny

Journal of Metals, Materials and Minerals

Spent zinc-carbon batteries of all the five types (AAA, AA, C, D and 9V) were processed to recover zinc metal. All the components of the battery were separated, chemically analyzed and the anodic zinc parts were subjected to pyrometallurgical processing. Extraction of zinc was negligible when no fluxing agent was used. However, extent of recovery increased significantly when chloride salts: sodium chloride, calcium chloride and ammonium chloride were used as a fluxing agent. Among these, ammonium chloride gave the best result as flux. Using 10 %wt. of each flux, extraction of zinc was 90% for ammonium chloride, and around 75% …

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Highly Porous Silica Network Prepared From Sodium Metasilicate, R E. Essien, O A. Olaniyi, L A. Adams, R O. Shaibu Dec 2011

Highly Porous Silica Network Prepared From Sodium Metasilicate, R E. Essien, O A. Olaniyi, L A. Adams, R O. Shaibu

Journal of Metals, Materials and Minerals

Porous silica network was prepared from sodium metasilicate (Na2SiO3) at room temperature (27C) using hydrochloric acid (HCl) as catalyst through the sol-gel method. The gel was dried at 120C for 1 day and calcined at 800C for 3 hours and the material obtained characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed the formation of amorphous silica particles of average sizes 598 nm with ordered porous network of pore sizes ranging from 0.18-0.91 ?m. This synthetic route uses sodium metasilicate as commercial precursor without pore forming templates which could be useful …

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Ni Electroless Plating Of Abs Polymer By Palladium And Tin-Free Process, P Dechasit, W Trakarnpruk Dec 2011

Ni Electroless Plating Of Abs Polymer By Palladium And Tin-Free Process, P Dechasit, W Trakarnpruk

Journal of Metals, Materials and Minerals

A palladium and tin-free process for the Ni electroless plating of acrylonitrile-butadiene-styrene (ABS) polymer has been developed. The ABS was first etched then activated with Ni (or Co) ions. Ni or Co adsorbed was quantified by atomic absorption spectroscopy. Sodium borohydride solution was found to be effective in reduction of Ni (or Co) ions. By immersing in a Ni plating bath the Co (or Ni) can then auto-catalytically deposit a Ni film on the ABS. The amount and thickness of Ni film determined by SEM-EDX were the highest when using 3 g/L of nickel acetate solution, 0.5 M sodium borohydride …

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Preparation Of Copper Lead Frame By Powder Metallurgy Technique, P Y. Chew, A H. You, T R. Vijayaram, B K. See, P S. Lim, M C. Ng Dec 2011

Preparation Of Copper Lead Frame By Powder Metallurgy Technique, P Y. Chew, A H. You, T R. Vijayaram, B K. See, P S. Lim, M C. Ng

Journal of Metals, Materials and Minerals

Pure Cu is prepared with the dimension of 17.7 mm in diameter and 10 - 15 mm in height using powder metallurgical method to characterize its electrical and mechanical properties. These samples are compacted at a constant pressure of 280 MPa. Pure Cu pellets are sintered at 600C and 950C for 3, 4 and 7 hours. Before sintering, pure Cu pellet is subjected to SEM in order to check the compactness of the pellet, and also the grain structure of the Cu. All the pellets with different temperatures are re-weighed and sintered density are calculated after sintering. Besides that, porosity …

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4-(N,N-Diethylamino)Benzaldehyde Thiosemicarbazone As Corrosion Inhibitor For 6061 Al - 15 Vol. Pct. Sic(P) Composite And Its Base Alloy, G M. Pinto, J Nayak, A N. Shetty Dec 2011

4-(N,N-Diethylamino)Benzaldehyde Thiosemicarbazone As Corrosion Inhibitor For 6061 Al - 15 Vol. Pct. Sic(P) Composite And Its Base Alloy, G M. Pinto, J Nayak, A N. Shetty

Journal of Metals, Materials and Minerals

The inhibitive action of 4-(N,N-diethylamino)benzaldehyde thiosemicarbazone (DEABT) on the corrosion behavior of 6061 Al -15 vol. pct. SiC(p) composite and its base alloy was studied at different temperatures in sulfuric acid medium containing varying concentrations of it, using Tafel extrapolation and AC impedance spectroscopy (EIS) techniques. Results showed that DEABT was an effective inhibitor, showing inhibition efficiency of 80 % in 0.5 M sulfuric acid. The adsorption of DEABT on both the composite and the base alloy was found to be through physisorption obeying Langmuirs adsorption isotherm.The thermodynamic parameters such as free energy of adsorption and activation parameters were calculated.

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Synthesis Of Aligned Carbon Nanotubes By Floating Catalyst Method Using Ferrocene, R Ravindra, B R. Bhat Dec 2011

Synthesis Of Aligned Carbon Nanotubes By Floating Catalyst Method Using Ferrocene, R Ravindra, B R. Bhat

Journal of Metals, Materials and Minerals

The aligned carbon nanotubes (CNTs) have been synthesised by floating catalyst method using ferrocene as catalyst precursor and acetylene as carbon precursor. The reaction was carried out at 850C in double stage chemical vapor deposition (CVD) apparatus. The grown aligned CNTs were purified by air oxidation and acid treatment method. The aligned CNTs were characterised by using scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The purity of CNTs was determined by Thermal analysis and X-ray diffraction method. The average diameter of aligned CNTs were around 20nm. This process not only produces aligned CNTs but also avoids the preparation …

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Multi-Properties Of Chitosan/Montmorillonite Composite Films Incorporated With Virgin And Modified Montmorillonite, S Kittinaovarat, W Nitayaphat, N Jiratumnukul, S Charuchinda Dec 2011

Multi-Properties Of Chitosan/Montmorillonite Composite Films Incorporated With Virgin And Modified Montmorillonite, S Kittinaovarat, W Nitayaphat, N Jiratumnukul, S Charuchinda

Journal of Metals, Materials and Minerals

Chitosan (CTS) composite films were prepared by blending CTS with virgin or modified montmorillonite (vMMT or mMMT, respectively) and then spin coating. XRD analysis showed a good intercalation of CTS and the mMMT in the depolymerized 15 kDa CTS/mMMT composite. The tensile strength and rigidity of the CTS/vMMT and CTS/mMMT composite films increased, whilst the elongation at break decreased, with increasing levels of vMMT or, especially, mMMT from 0.1 to 2% (w/w). Both types of CTS/MMT composite films displayed a decreased oil and water absorption with increasing levels of incorporated vMMT or mMMT. Some aggregation of vMMT but not mMMT …

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Mechanical Properties Of Stir-Mixed Sicp-Reinforced Aluminium Composites, R Buntan, D Phuenchomphu, P Sukmoung, K Doomao, O Anunapiwat, T Patcharawit Dec 2011

Mechanical Properties Of Stir-Mixed Sicp-Reinforced Aluminium Composites, R Buntan, D Phuenchomphu, P Sukmoung, K Doomao, O Anunapiwat, T Patcharawit

Journal of Metals, Materials and Minerals

Aluminium composites have found their strength in engineering applications such as automotive, electrical and light-weight applications. To achieve uniform microstructure and good mechanical properties, the fabrication techniques are prime factors in controlling wettability and porosity problems. This research therefore aimed for studying microstructure-mechanical property relation of SiCp-reinforced 356 aluminium composites fabricated by a cost-effective stir casting process, to which three elemental additions, Al-5Ti-B, Sr, and Mg,were investigated. Furthermore, effects of SiCp additions (0-15 wt.%) and T6 heat treatment (530C/12h + 155C/4 h) on mechanical properties of the composites were also studied. The 356 aluminium ingot was melted at 700C then …

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Process Parameter-Microstructure-Mechanical Property Relations Of Sicp-Reinforced Aluminum Composites Produced By Powder-Injection Casting, M Bunma, P Subarporn, R Bobuangern, T Patthannkitdamrong, T Thuanwong, T Patcharawit Dec 2011

Process Parameter-Microstructure-Mechanical Property Relations Of Sicp-Reinforced Aluminum Composites Produced By Powder-Injection Casting, M Bunma, P Subarporn, R Bobuangern, T Patthannkitdamrong, T Thuanwong, T Patcharawit

Journal of Metals, Materials and Minerals

Aluminum composites are of interest for engineering applications such as electrical and especially automotive applications and their final physical and mechanical properties are usually determined by fabrication techniques. This research aimed to study effects of process parameters, which are i) argon gas flow rates at 5 and 10 l/min, and ii) casting temperatures at 620 and 680C, on integrity of the SiCp-reinforced 356 aluminum composites fabricated by powder-injection casting using a modified flux injection degassing machine. The SiCp additions are 0, 10 and 15 wt.%. Microstructure - mechanical property relations were constructed based on the predetermined process parameters. Aluminum 356 …

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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 Jul 2011

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. …

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