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Articles 12511 - 12540 of 16699

Full-Text Articles in Engineering

Design, Fabrication, Modeling And Characterization Of Electrostatically-Actuated Silicon Membranes, Brian C. Stahl Dec 2008

Design, Fabrication, Modeling And Characterization Of Electrostatically-Actuated Silicon Membranes, Brian C. Stahl

Master's Theses

This thesis covers the design, fabrication, modeling and characterization of electrostatically actuated silicon membranes, with applications to microelectromechanical systems (MEMS). A microfabrication process was designed to realize thin membranes etched into a silicon wafer using a wet anisotropic etching process. These flexible membranes were bonded to a rigid counterelectrode using a photo-patterned gap layer. The membranes were actuated electrostatically by applying a voltage bias across the electrode gap formed by the membrane and the counterelectrode, causing the membrane to deflect towards the counterelectrode. This deflection was characterized for a range of actuating voltages and these results were compared to the …

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Preparation And Characterization Of Particles From Chitosan With Different Molecular Weights And Their Trimethyl Chitosan Derivatives For Nasal Immunization, W Boonyo, H E. Junginger, N Waranuch, A Polnok, T Pitaksuteepong Dec 2008

Preparation And Characterization Of Particles From Chitosan With Different Molecular Weights And Their Trimethyl Chitosan Derivatives For Nasal Immunization, W Boonyo, H E. Junginger, N Waranuch, A Polnok, T Pitaksuteepong

Journal of Metals, Materials and Minerals

According to previous studies, molecular weights (MW) of chitosan presented an influence on the level of immune response to model antigen when administering with chitosan through nasal route. Moreover, trimethyl chitosan (TMC) with a degree of quaternization (DQ) of 40%, chitosan derivatives, was also shown to be the most potent nasal OVA delivery platforms compared to TMC with DQ of 20% and 60% in mice model. The aims of this study were to prepare particles from chitosan with difference MW and their TMC derivatives (DQ = 40%) and to characterize size, zeta potential, loading efficiency and release profile in order …

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Chitosan/Calcium Phosphate Composites Scaffolds Prepared By Membrane Diffusion Process, P Thanaphat, P Thunyakitpisal, W Techaboonyakiat Dec 2008

Chitosan/Calcium Phosphate Composites Scaffolds Prepared By Membrane Diffusion Process, P Thanaphat, P Thunyakitpisal, W Techaboonyakiat

Journal of Metals, Materials and Minerals

Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) and Dicalcium phosphate dihydrate (CaHPO4.H2O, DCPD) were homogeneously hybridized into chitosan solution by membrane diffusion process. The threedimensional scaffolds were obtained by freeze-drying process. The organic and inorganic contents of scaffold were determined by using thermogravimetry analysis (TGA). The surface morphology of the scaffold and characteristic of calcium phosphate were investigated by scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDX), and X-ray diffraction (XRD), respectively. Compressive modulus was also determined by dynamic mechanical analysis (DMA). The hybridized inorganic content ranges from 35-45%. Both chitosan/HAp and chitosan/DCPD scaffolds showed interconnected porous structure. The calcium to phosphorus ratios …

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Utilizing Quantum Dots To Enhance Solar Spectrum Conversion Efficiencies For Photovoltaics, Richard N. Savage, Hans Mayer, Matthew Lewis, Dan M. Marrujo Dec 2008

Utilizing Quantum Dots To Enhance Solar Spectrum Conversion Efficiencies For Photovoltaics, Richard N. Savage, Hans Mayer, Matthew Lewis, Dan M. Marrujo

Materials Engineering

Silicon-based photovoltaics typically convert less than 30% of the solar spectrum into usable electric power. This study explores the utilization of CdSe based quantum dots as spectral converters that absorb the under utilized UV portion of the solar spectrum and fluoresce at wavelengths near the band-gap of silicon-based solar cells. A flexible 1 mm thick thin-film structure that contains an array of microfluidic channels is designed and fabricated in polydimethylsiloxane (PDMS) using soft-lithographic techniques. The channels are approximately 85 microns wide by 37 microns tall and are filled with a solution containing the quantum dots. The thin-film structure can easily …

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Room-Temperature Single-Electron Devices Based On Cmos Fabrication Technology, Vishva Priyo Ray Dec 2008

Room-Temperature Single-Electron Devices Based On Cmos Fabrication Technology, Vishva Priyo Ray

Material Science and Engineering Dissertations - Archive

Single-electron devices, in which the transport and storage of individual electrons is precisely controlled, have many potential benefits in the field of electronics, optics, and sensors. Fabrication of these devices requires the arrangement of device components (Coulomb island, source, drain, and gate electrodes) with nanometer scale precision. Although several methods have successfully demonstrated single-electron behavior, large-scale fabrication of single-electron devices has not been possible.This research aims to - * Come up with a method which would allow the fabrication of single-electron devices on a large scale,* Make the fabrication method compatible with current CMOS technology, and,* Enable room-temperature operation of …

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Electrodeposition Of Nickel Nanowires And Nanotubes Using Various Templates, Asli Ertan, Surendra N. Tewari, Orhan Talu Dec 2008

Electrodeposition Of Nickel Nanowires And Nanotubes Using Various Templates, Asli Ertan, Surendra N. Tewari, Orhan Talu

Chemical & Biomedical Engineering Faculty Publications

Nickel nanotubes and nanowires are grown by galvanostatic electrodeposition in the pores of 1000, 100, and 15 nm polycarbonate as well as in anodised alumina membranes at a current density of 10 mA cm-2. The effects of pore size, porosity, electrodeposition time, effective current density, and pore aspect ratio are investigated. Nickel nanotube structures are obtained with 1000 nm pore size polycarbonate membrane without any prior treatment method. At the early stages of electrodeposition hollow nickel nanotubes are produced and nanotubes turn into nanowires at longer depositon times. As effective current density accounting for the membrane porosity decreases, the axial …

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Structural Properties And Crystallization Of Sodium Tellurite Glasses, Kresimir Furic, Masa Rajic-Linaric, C. S. Ray, A. Šantić, Andrea Moguš-Milanković, D. E. Day Dec 2008

Structural Properties And Crystallization Of Sodium Tellurite Glasses, Kresimir Furic, Masa Rajic-Linaric, C. S. Ray, A. Šantić, Andrea Moguš-Milanković, D. E. Day

Materials Science and Engineering Faculty Research & Creative Works

The structural properties and crystallization behaviour of xNa2O-(100-x)TeO2 (0 <= x <= 33.3, x-% mole fraction) glasses have been investigated by Raman spectroscopy, X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The Raman spectra of glasses show systematic changes in structural units, from TeO4 trigonal bypiramids (tbps) to TeO3 trigonal pyramids (tps) with increasing Na2O content in glass. These structural changes are result of Te-eqOax-Te disruption and the formation of non-bridging oxygens (NBOs) in glass network. when heated at 623 K for 10 h glasses crystallized to different phases: alpha-TeO2, Na2Te4O9 and a new crystalline phase which is believed to be a polymorph of Na2Te2O5.

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Preparation Of Ultrafine Silver Powder Using Glycerol As Reducing Agent, E Nisaratanaporn, K Wongsuwan Dec 2008

Preparation Of Ultrafine Silver Powder Using Glycerol As Reducing Agent, E Nisaratanaporn, K Wongsuwan

Journal of Metals, Materials and Minerals

The production of silver nanoparticles and sub-micron particles can be achieved by silver alkoxide from silver sulfate and subsequently reducing with glycerol. To reduce the particle size of silver sulfate precursors, ball milling was employed to reduce particle sizes down to 0.81 microns. However, silver sulfate without grinding provided smaller particle sizes of silver particles as opposed to ground specimens. Stirring silver alkoxide simultaneously was efficient to provide for uniform distribution of silver powder. The silver powder thus produced had brain-like shape consisted of very fine aggregate silver particles. The yield of silver powder was in the range of 95-99 …

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Influence Of Reinforced Plastomers On Injection Moulds Wear, A Guzanová, J Brezinová Dec 2008

Influence Of Reinforced Plastomers On Injection Moulds Wear, A Guzanová, J Brezinová

Journal of Metals, Materials and Minerals

The contribution deals with wear of injection moulds based on aluminium alloy Alumec 89 in friction couples with plastomers reinforced with different glass fibres content. Friction relations in injection moulding were simulated by adhesion dry wear test with help of Amsler equipment with area contact of friction couple. Wear intensity was evaluated by friction coefficient and relative wear by weight loss. Simultaneously, changes of aluminium alloy surface morphology after wear in particular friction couples were analysed.

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Demonstration Of The Ntc Ceramic Application For Temperature Measurement And Control Using The Labview-Based Measurement System, T Panmatarith, K Poatong Dec 2008

Demonstration Of The Ntc Ceramic Application For Temperature Measurement And Control Using The Labview-Based Measurement System, T Panmatarith, K Poatong

Journal of Metals, Materials and Minerals

In the present paper, ZnO+0.01SnO2 ceramics were prepared using a standard ceramic method. We present the NTC ceramic application for temperature measurement and control using the LabVIEW-based measurement system. The measured resistance of the sample at room temperature was about 6.5 kΩ. The electrical resistance versus temperature of the sample was measured. The negative temperature coefficient of resistance of the sample was -1.018 %/°C. This sample showed NTC effect and exhibited NTC resistor, indicating their potential application as temperature sensor with low cost. It can be used as temperature sensor by using the NTC effect . The measured temperature (T) …

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Production Of Sponge Rubber For Monolayer Rubber Stamp Using Salt Leaching Method, W Trakanpruk, Y Rodthong Dec 2008

Production Of Sponge Rubber For Monolayer Rubber Stamp Using Salt Leaching Method, W Trakanpruk, Y Rodthong

Journal of Metals, Materials and Minerals

Sponge rubber used for monolayer rubber stamp was produced from nitrile butadiene rubber (NBR). Open cells in sponge rubber were created using salt leaching method. Effect of size and amount of sodium chloride which was used as a water soluble salt on the creation of open cells in the rubber was investigated. Carbon black was used as a filler. A different type of surfactant was added to increase the leaching out of salt from the rubber. Cure characteristics of the compound rubbers: maximum torque, minimum torque, scorch time and cure time as well as hardness of the prepared sponge rubber …

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Application Of Chitosan In Rice Production, S Boonlertnirun, C Boonraung, R Suvanasara Dec 2008

Application Of Chitosan In Rice Production, S Boonlertnirun, C Boonraung, R Suvanasara

Journal of Metals, Materials and Minerals

Chitosan is a natural biopolymer which stimulates growth and increases yield of plants as well as induces the immune system of plants. The objectives of this study were to determine appropriate applications for increasing of the rice yield. The experiment was performed with randomized complete block design ( RCBD) with four replications. Four treatments were done as follows : no chitosan application, seed soaking with chitosan solution, seed soaking and soil application with chitosan solution and seed soaking and foliar spraying with chitosan solution. The results showed that application of chitosan by seed soaking and soil application four times throughout …

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Preparation Of N-Acetyl-D-Glucosamine Using Enzyme From Aspergillus Sp., P Setthakaset, R Pichyangkura, A Ajavakom, M Sukwattanasinitt Dec 2008

Preparation Of N-Acetyl-D-Glucosamine Using Enzyme From Aspergillus Sp., P Setthakaset, R Pichyangkura, A Ajavakom, M Sukwattanasinitt

Journal of Metals, Materials and Minerals

N-acetyl-D-glucosamine (GlcNAc) is one of the basic constituents of mammal cartilage, which is known to help repair deteriorating cartilage and relieve pain and inflammation in osteoarthritis patients. The preparation of GlcNAc from squid pen β-chitin by using Aspergillus sp. chitinase in enzymatic hydrolysis is studied. The cultivation of the fungus in colloidal chitin minimum media at pH 3.5 and 40°C for 5 days gives the highest chitinolytic activity of 3.1 U/mL. The crude enzyme obtained from the the cultivation is used in the hydrolysis of milled squid pen β-chitin (50μm) at pH 4 (acetic acid 2M) and 45°C using 22 …

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Factors Affecting Preparations Of Chitosan Microcapsules For Colonic Drug Delivery, K Huanbutta, M Luangtana-Anan, P Sriamornsak, S Limmatvapirat, S Puttipipatkhachorn, J Nunthanid Dec 2008

Factors Affecting Preparations Of Chitosan Microcapsules For Colonic Drug Delivery, K Huanbutta, M Luangtana-Anan, P Sriamornsak, S Limmatvapirat, S Puttipipatkhachorn, J Nunthanid

Journal of Metals, Materials and Minerals

This work aimed at studying factors affecting preparations of chitosan microcapsules for colonic drug delivery. Chitosan microcores (CS, 45kDa, 87% degree of deacetylation) containing diclofenac sodium (DS) coated with Eudragit®S100 (ED) were prepared by a desolvation technique. Sodium sulfate was used as a desolvating agent and the drying process was freeze-drying. Factors affecting morphology, particle size and zeta potential of microcapsules were evaluated, i.e. weight ratio of DS:CS:ED, surfactant (polysorbate 80), anti-adherent (silicon dioxide), and the use of sonication or homogenization in preparation processes. The weight ratio of DS:CS:ED at 1:2:6 provided the smallest microcapsules of about 82.37±1.61 micrometer in …

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Fabrication Of Porous Bioactive Glass-Ceramics Via Decomposition Of Natural Fibres, P Sooksaen, S Suttiruengwong, K Oniem, K Ngamlamiad, J Atireklapwarodom Dec 2008

Fabrication Of Porous Bioactive Glass-Ceramics Via Decomposition Of Natural Fibres, P Sooksaen, S Suttiruengwong, K Oniem, K Ngamlamiad, J Atireklapwarodom

Journal of Metals, Materials and Minerals

Porous bio glass-ceramics were prepared via natural fibres burning-out process. Glass-ceramics were fabricated by controlled crystallization of suitable glass compositions to give required crystalline phase/s. Porous structure was formed alongside during burning-out of natural fibres. Three glass batches were prepared in the SiO2-CaO-P2O5-K2O-Na2O-CaF2 glass system, then melted, quenched and milled to give fine glass powders. DTA thermograms for the three glass compositions showed crystallization temperatures between 720 and 760°C and Tg ranging between 508 and 645°C. Porous glass-ceramics were characterized for bulk density, phase evolution and microstructures. Different compositions resulted in different bulk densities and phases that crystallized out. Fluorapatite …

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Water Soluble Chitosan As An Environment-Friendly Coagulant In Removal Of Rubber Particles From Skim Rubber Latex, R Werathirachot, P Danwanichakul, C Kongkaew, S Loykulnant Dec 2008

Water Soluble Chitosan As An Environment-Friendly Coagulant In Removal Of Rubber Particles From Skim Rubber Latex, R Werathirachot, P Danwanichakul, C Kongkaew, S Loykulnant

Journal of Metals, Materials and Minerals

Water soluble chitosan, dissolved in hot deionized water to obtain 0.8% solution, was used for the coagulation-flocculation of skim natural rubber latex. The efficiency of coagulation-flocculation of skim rubber latex without pH adjustment was much poorer than that of neutral skim rubber latex. When adding chitosan solution to the neutral skim rubber latex with a rubber content of 5.300 %wt/vol until the concentration of chitosan in the dispersion was 0.107%, the phase separation between rubber particles and yellow serum was clearly observed. At this condition, the removal efficiency of skim rubber particles was found to be the best among all …

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Fabrication Of Al/Al2o3 Composite By Powder Metallurgy Method From Aluminum And Rice Husk Ash, C Dhadsanadhep, T Luangvaranunt, J Umeda, K Kondoh Dec 2008

Fabrication Of Al/Al2o3 Composite By Powder Metallurgy Method From Aluminum And Rice Husk Ash, C Dhadsanadhep, T Luangvaranunt, J Umeda, K Kondoh

Journal of Metals, Materials and Minerals

Fabrication of Al-4wt.%Cu /Alumina composite was reported. The method of fabrication was powder metallurgy by in-situ reaction to form alumina during fabrication. Starting materials were mixture of aluminum, copper, and silica powders. Silica is in form of rice husk ash. The mixture was cold compacted, and sintered at 650°C for 1 h. Hot forging was carried out to further consolidate the sintered billet, followed by 10-h heat treatment at temperatures between 590 to 650°C. Phase analysis by XRD confirmed that in-situ reaction between silica and aluminum powders occurred during heat treatment at temperatures above 590°C. The products of reaction were …

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Improvements In Steel Melting Efficiency -- Industrial Trials, Kent D. Peaslee, Semen Naumovich Lekakh, Edith Martinez Dec 2008

Improvements In Steel Melting Efficiency -- Industrial Trials, Kent D. Peaslee, Semen Naumovich Lekakh, Edith Martinez

Materials Science and Engineering Faculty Research & Creative Works

Industrial trials were completed to improve energy efficiency in steel melting. First, the benefits of increased chemical energy from an oxyfuel burner and a Co-Jet system in a basic 20 ton electric arc furnace (EAF) were studied. Observations and measurements were made during production before and after the installation of the two systems. The additional chemical energy improved energy efficiency and resulted in increased production. In addition, production using a basic EAF practice was compared to the traditional acid EAF practice. Second, an industrial trial using a 750 lb ladle with a combination of a lightweight alumina castable refractory and …

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Energy Efficiency In Steel Casting Production, Raymond Monroe, Kent D. Peaslee, R. Eppich Dec 2008

Energy Efficiency In Steel Casting Production, Raymond Monroe, Kent D. Peaslee, R. Eppich

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

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Intergranular Phases In Cyclically Annealed Yba2cu3o7-X And Their Implications For Critical Current Densities, Andrew Peter Clarke Dec 2008

Intergranular Phases In Cyclically Annealed Yba2cu3o7-X And Their Implications For Critical Current Densities, Andrew Peter Clarke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We report changes in the intergranular material and grain morphology of YBa2Cu3O7-x during cyclic anneals between 780 and 980 ºC in oxygen at atmospheric pressure. Two endothermic reactions were detected: (a) the eutectic reaction of YBa2Cu3O7-x with CuO and BaCuO2 at 900 ºC (enthalpy ∆Ha) and (b) the peritectic reaction of YBa2Cu3O7-x with CuO at 950 ºC (∆Hb). During the first anneal, only reaction (b) is detected, and although it should only occur if there is an excess of CuO, …

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Chitin Nanowhisker And Chitosan Nanoparticles In Protein Immobilization For Biosensor Applications, P Na Nakorn Dec 2008

Chitin Nanowhisker And Chitosan Nanoparticles In Protein Immobilization For Biosensor Applications, P Na Nakorn

Journal of Metals, Materials and Minerals

In this study, bovine serum albumin (BSA) was used as a model protein for the optimization of protein immobilization on chitin nanowhisker and chitosan nanoparticles under different conditions. Chitosan nanoparticles showed better results than chitin in this immobilization purpose. The immobilization at 15 minutes, pH 6 and 20-25°C was the optimal condition. Subsequently, glucose oxidase (GOD), enzyme used for glucose determination, was applied in order to investigate the optimum immobilization condition on chitosan nanoparticles. The optimal condition prove to…at pH 7, 30°C and 0.5 mg/ml of initial GOD concentration via immobilization at 15 minutes. Chitin nanowhisker and chitosan nanoparticles in …

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Using Automated Inclusion Analysis For Casting Process Improvements, Vintee Singh, Semen Naumovich Lekakh, Kent D. Peaslee Dec 2008

Using Automated Inclusion Analysis For Casting Process Improvements, Vintee Singh, Semen Naumovich Lekakh, Kent D. Peaslee

Materials Science and Engineering Faculty Research & Creative Works

Different industrial melting and ladle practices (deoxidation, slag, refractory types, etc.) used in steel foundries were analyzed and compared using an ASPEX automated inclusion analyzer for study of inclusions. The effects of deoxidation and pouring practices on the size, type and number of inclusions were evaluated for steel foundries equipped with induction and arc melting furnaces, with capacities ranging from 1 to 20 tons. Samples were collected from the furnace, ladle, and castings. Specific rules were developed for classification of inclusions by composition, size distribution and shape. Inclusion statistics, including composition, quantity, shape, and size during cast steel processing from …

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'Fabrication And Characterization Of Polymer Blends And Composites Derived From Biopolymers', Suraj Sharma Dec 2008

'Fabrication And Characterization Of Polymer Blends And Composites Derived From Biopolymers', Suraj Sharma

All Dissertations

This research focuses on fabricating blends and composites from natural polymers especially from proteins and natural epoxy, and describing the properties of plastics made from them. Specifically, plastic samples from partially denatured feathermeal and bloodmeal proteins, derived from the animal co-products (rendering) industry, were successfully produced through a compression molding process. The modulus (stiffness) of the material obtained was found to be comparable with that of commercial synthetic materials, such as polystyrene, but was found to have lower toughness characteristics, which is a common phenomenon among plastics produced from animal and plant proteins. Therefore, this study explored blending methods for …

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Synthesis And Characterization Of Macromolecular Layers Grafted To Polymer Surfaces, Oleksandr Burtovyy Dec 2008

Synthesis And Characterization Of Macromolecular Layers Grafted To Polymer Surfaces, Oleksandr Burtovyy

All Dissertations

The composition and behavior of surfaces and interfaces play a pivotal role in dictating the overall efficiency of the majority of polymeric materials and devices. Surface properties of the materials can be altered using surface modification techniques. It is necessary to highlight that successful methods of surface modification should affect only the upper layer of the polymer material without changing bulk properties. The processes must introduce new functionalities to the surface, optimize surface roughness, lubrication, hydrophobicity, hydrophilicity, adhesion, conductivity, and/or biocompatibility.
Research presented in this dissertation is dedicated to the synthesis, characterization, and application of thin macromolecular layers anchored to …

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Properties Evaluation Of Sodium Nitrite Treated Chitosan-Cotton Fabric, S Srisuk, K Srikulkit Dec 2008

Properties Evaluation Of Sodium Nitrite Treated Chitosan-Cotton Fabric, S Srisuk, K Srikulkit

Journal of Metals, Materials and Minerals

In this study, chitosan coated-cotton fabric was prepared and then treated with sodium nitrite under mild condition, aiming at the partial removal of surface-chitosan in order to solve the problems of surface dyeing and fabric stiffness. The results showed that sodium nitrite treated chitosan-fabric exhibited an improvement of dyeability (higher dye exhaustion and color strength) when compared to untreated fabric. The improvement in dyeability was due to the availability of chitosan amino groups which had an affinity to anionic dyes including reactive dyes. Other fabric properties were evaluated. The results showed that color fastness properties (crocking fastness and light fastness) …

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Behavior Of Copper Electrodeposition In Copper Electroplating Solution With Different Peg Molecular Weight, Lie Yin, Zeng-Lin Wang Nov 2008

Behavior Of Copper Electrodeposition In Copper Electroplating Solution With Different Peg Molecular Weight, Lie Yin, Zeng-Lin Wang

Journal of Electrochemistry

The effect of the polyethylene glycol(PEG) molecular weight(MW) upon via-hole filling with diameter of 50 μm and aspect ratio of 1 in the acid copper plating solution was studied.The cathodic polarization in copper electroplating bath with PEG of different molecule weights was investigated by linear sweep voltammetry.The surface roughness,crystallography,and the resistivity of copper films were characterized by X-ray diffraction(XRD),atomic force microscopy(AFM) and the four-point probe measurements.The results showed that the polarization on the cathode and the hole-filling capability of electroplating copper bath were increased evidently with an increase of PEG molecular weight from 600 to 8000.When the PEG MW was …

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Voltammetric Determination Of Iodate Ion In Table Salt By Carboxylic Carbon Nanotubes Modified Carbon Paste Electrode, Jun-Hua Li, Fu-Xing Zhang, Jian-Qiu Wang, Zhi-Feng Xu, Rong-Ying Zeng, Yan Yu Nov 2008

Voltammetric Determination Of Iodate Ion In Table Salt By Carboxylic Carbon Nanotubes Modified Carbon Paste Electrode, Jun-Hua Li, Fu-Xing Zhang, Jian-Qiu Wang, Zhi-Feng Xu, Rong-Ying Zeng, Yan Yu

Journal of Electrochemistry

A highly-sensitive and mercury-free method of determining iodate ion in table salt was established based on carboxylic carbon nanotubes modified carbon paste electrode.In 0.1 mol/L NaOH solution,there was a sensitive cathodic stripping peak on voltammograms.The stripping peak potential was-0.52 V when accumulation time of IO-3 at the modified electrode was 60 s and the potential scan rate was 300 mV/s.There was a good liner relationship between the peak current and IO-3 concentration in the range of 8.0×10-10 ～ 5.0×10-8 mol/L and 1.0×10-7 ～ 3.0×10-6 mol/L with the correlation coefficient of 0.999 and 0.998,respectively.The detection limit was …

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Primary Study Of Tiron As Active Materials For The Redox Flow Battery, Yan Xu, Yue-Hua Wen, Jie Cheng, Yu-Sheng Yang, Zi-Li Xie Nov 2008

Primary Study Of Tiron As Active Materials For The Redox Flow Battery, Yan Xu, Yue-Hua Wen, Jie Cheng, Yu-Sheng Yang, Zi-Li Xie

Journal of Electrochemistry

Effects of solution pH on the electrochemical behavior of tiron(sodium 4,5-dihydroxy-1,3-benzendisulfonic) couple(on a graphite electrode) were studied by cyclic voltammetry in aqueous solutions.It is shown that at pH<4,tiron exhibited a redox process at a relatively high potential with a good reversibility.A redox flow battery was formed employing tiron as the positive active species and V(III)/V(II) as the negative redox couple.In sulfuric acid medium,the coulombic efficiency of the tiron-V redox flow cell was more than 90% with a good cycle life.The decay in the cycle performance was minimal.Therefore,the feasibility of tiron as active materials for redox flow battery application is demonstrated.

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Combustion Product Characterization Of The Iron-Heated Powders In Thermal Batteries, Jin Chong, Xue-Ping Gao, Ji-Qiang Wang Nov 2008

Combustion Product Characterization Of The Iron-Heated Powders In Thermal Batteries, Jin Chong, Xue-Ping Gao, Ji-Qiang Wang

Journal of Electrochemistry

The combustion products of thermal battery used iron-heated powders have been studied.It is identified by X-ray diffraction (XRD) analysis that the main compositions of the combustion products are Fe, FeO and KCl. The transmission electron microscopy(TEM) shows a typical core-shell structure with un-reacted Fe particle core coated by FeO shell with a shell thickness of around 200 nm. The combusted iron-heated powders exhibit no metal property, which is contrast to previous assumption. Further measurement indicates that at the ambient temperature the combustion products show semiconductor property of the p-type with conductivity in the order of 103 S·cm-1, which …

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Preparation And Electrocatalystic Performance Of Ir/C Catalyst For Ammonia Oxidation, Qing-Mei Kong, Yi-Ping Han, Ling-Juan Deng, Tian-Hong Lu, Ya-Wen Tang Nov 2008

Preparation And Electrocatalystic Performance Of Ir/C Catalyst For Ammonia Oxidation, Qing-Mei Kong, Yi-Ping Han, Ling-Juan Deng, Tian-Hong Lu, Ya-Wen Tang

Journal of Electrochemistry

The Ir/C catalyst with 30%(by mass) Ir was prepared in the CH3CH2OH and H2O binary system.The X-ray diffraction(XRD) data showed that the average sizes of the Ir particles in the Ir/C catalyst was about 2.2 nm.The results of the electrochemical measurements indicated that the electrocatalytic activity of the Ir/C catalyst for the ammonia oxidation in the neutral NaClO4 solution was similar to the Ir catalyst,while electrocatalytic stability was much better than that of the Ir catalyst.Furthermore,the peak current density of the ammonia oxidation at the Ir/C catalyst electrode showed a good linear relationship …

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