Materials Science and Engineering Commons^™

Method And System For Electronically Generating Random Answers, Stephen O. Bozzone, Bonnie Bachman

Economics Faculty Research & Creative Works

The invention concerns a method (300) and system (110) for electronically generating random responses in a portable electronic device (110). The method includes the steps of detecting (316) motion of the portable electronic device, in response to the detecting step, generating (318) the random response and outputting (320) the random response to a user of the portable electronic device. The method can further include the steps of prompting (312) the user to ask a question and following a predetermined time period after prompting the user to ask the question, prompting (314) the user to shake the portable electronic device. The …

College Of Engineering Senior Design Competition Fall 2005, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …

Multiple Channel Laser Beam Combination And Phasing Using Stimulated Brillouin Scattering In Optical Fibers, Brent W. Grime

Theses and Dissertations

Brightness scaling lasers using stimulated Brillouin scattering (SBS) in optical fibers is explored. A multiple-channel amplifier approach is used to increase the total power of a laser system while avoiding a significant burden on a single channel. The work explores two approaches utilizing both SBS beam cleanup and SBS piston error conjugation. A unique beam combiner that takes advantage of the SBS beam cleanup properties of a long, gradient-index multimode fiber was designed and tested. The beam combiner was developed to combine multiple-channel laser beams simultaneously with high input and output coupling efficiency. The design for the SBS beam combiner …

Interactions Between Antiwear Agent And Novel Additive In Engine Oils, Kajal Parekh

Material Science and Engineering Theses - Archive

Research has shown that side/end products of phosphorus and sulfur compounds in engine oils reduce effective life of exhaust catalysts of automobiles resulting in harmful emissions. Thus environmental regulations have been imposed on phosphorus levels in engine oils. The main source of phosphorus in today's oils is the indispensable antiwear agent Zinc Dialkyl Dithiophosphate (ZDDP). To find cost-effective non-phosphorus substitute has not proven fruitful. A unique way of reducing phosphorus or ZDDP level while maintaining good antiwear performance has been achieved by introduction of a novel additive FeF3 along with ZDDP. It appears that the interactions between FeF3 and ZDDP …

Ferroelectric Switch For Spin Injection, Mikhail Ye. Zhuravlev, Sitaram Jaswal, Evgeny Y. Tsymbal, Renat F. Sabirianov

Materials Research Science and Engineering Center: Faculty Publications

A method for the switching of the spin polarization of the electric current injected into a semiconductor is proposed, based on injecting spins from a diluted magnetic semiconductor through a ferroelectric tunnel barrier. We show that the reversal of the electric polarization of the ferroelectric results in a sizable change in the spin polarization of the injected current, thereby providing a two-state electrical control of this spintronic device. We also predict a possibility of switching of tunneling magnetoresistance in magnetic tunnel junctions with a ferroelectric barrier and coexistence of tunneling magnetoresistance and giant electroresistance effects in these multiferroic tunnel junctions.

Solid Oxide Fuel Cells-Materials And Prospects, Molenda Janina, Marzec Jacek

Journal of Electrochemistry

The paper summarizes and discusses the basic properties of solid oxide fuel cell (SOFC) components (electrode materials and electrolyte) from the point of view of their essential functional parameters suck as chemicalstability, transport, catalytic and thermomechanical properties under operational conditions in a SOFC. An interrela-tion between the defect structure of these materials related to oxygen nonstoichiometry and their electronic propertiesand catalytic activity was shown. Single-chamber fuel cell concept was also presented.

A Continuous Operation For Electroreduction Of Oxalic Acid To Glyoxylic Acid, Xiao-Hui Hu, Xiang-Fei Yan, Yu-Zhong Su, Jun Li, Qing-Biao Li

Journal of Electrochemistry

A simulative-continuous-operation approach was proposed to study the continuous operation for electroreduction of oxalic acid to gloxylic acid using a packed bed reactor and a parallel reactor with cooled cathode in order to solve the low productivity problem in current state by using traditional reactor. The effects of the concentration of oxalic acid and temperature on this process were also studied. Results showed that,after 30min of the reaction(residence time), the mass fraction of the produced glyoxylic acid in the catholic solution could reach 3.76% and 3.66% with respect to a saturated oxalic acid method and a step-temperature decreasing method. From …

The Mechanism Of Ethylenediamine On Electroless Ni-B Alloy Deposition, Sen-Lin Wang

Journal of Electrochemistry

The effects of ethylenediamine stabilizer on the deposition rate and on the stability of the plating bath for electroless deposition of Ni-B alloy were investigated. It was found that the addition of ethylenediamine greatly enhances the stability of the electroless plating bath. The electrochemical polarization including cathodic and anodic polarizations measurements were carried out to examine the effect of ethylenediamine on the deposition process. The results show that ethylenediamine affects both the cathodic and the anodic polarization processes. The oxidation current of the reducer and the reduction current of Ni-B alloy decrease greatly when ethylenediamine was added into the plating …

The Optimal Sulfonation Conditions Of Self-Doped Polyaniline Obtained By Using Experimental Strategies, Wen-Yar Li, Chi-Chang Hu

Journal of Electrochemistry

The optimal sulfonation condition of self-doped sulfonated polyaniline (prepared from leucoemeraldinebase; denoted as LEB-SPANI) with a high electronic conductivity was obtained by experimental strategies, includingthe fractional factorial design (FFD) and central composite design (CCD). From the FFD experiment, the self-doped LEB-SPANI prepared at a lowtemperature (4℃), a short reaction time (1 h), and a small volume of fumingsulfuric acid (10 mL) showed a better conductivity (ca.127 mS/cm). In the CCD study coupled with a confirmationtest, the highest conductivity (ca.141 mS/cm) of the LEB-SPANI film was obtained under a sulfonation temperatureof 4℃, a sulfonation time of 75 minutes, and a volume …

The High Temperature Corrosion Of 2205 Duplex Stainless Steel With Nacl Deposit, Fu-Fu Peng, Chaur-Jeng Wang, Yu-Chang Lin

Journal of Electrochemistry

The objective of this study was to figure out the hot corrosion behavior of 2205 duplex stainless steel (2205 DSS) within the temperature ranges from 550 to 850℃ in the static air condition with 2 mg/cm² NaCl deposit, and in the air atmosphere condition with a constant flow rate of 500 vppm NaCl_(g), respectively. Experimental results show that the hot corrosion kinetics met the parabolic rate law and the corrosion rate increased constantly with increasing temperature. The scales formed included Fe₂O₃/Fe₃O₄/Cr₂O₃ and FeCr₂O_{4 …}

A Study Of Three Corrosion Inhibitors For Reinforcing Steel In Sps Solution By Electrochemical Methods, Bing Zhao, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

Some electrochemical techniques such as linear polarization,electrochemical noise and EIS have been employedto study the inhibition behavior of N-lauroyl sarcosinate, β-sodium glycerophosphate and D-sodium gluconate for the reinforcing steel immersed in simulated concrete pore solution(SPS) with NaCl addition.The results show that D-sodium gluconatehas an obvious inhibitive effect for the reinforcing steelin containing Cl^- SPS solution. It has been proposed that the corrosion inhibition of D-sodium gluconate is due to its competitive adsorption and precipitation on steel surface in the simulated concrete environment.

Effect Of Hco3- Concentration On Co2 Corrosion In Gas And Oil Fields, Guo-An Zhang, Min-Xu Lu, Yin-Shun Wu

Journal of Electrochemistry

The effecs of HCO₃^- concentration on CO₂ corrosion in gas and oil fields were investigated by carrying out potentiodynamic scans and weight loss tests.Potentiodynamic polarization curves showed that the cathodic current density decreased with cm increase of HCO₃^- concentration when HCO₃^- was lower than 0.042(mol/L). The cathodic reations were promoted by increasing HCO₃^- when it reached 0.126 mol/L, Anodic behavior was an active process at low er [HCO₃^-] concentration and the anodic current density decreased with the increase of [HCO₃^-] concentration. An evident active-passive behavior …

A Study Of Overcharge Characteristic Of Lithium-Ion Cells, Jing Pang, Shi-Gang Lu, Sha Liu

Journal of Electrochemistry

The overcharge characteristics and effect factors of lithium-ion cells containing LiMn₂O₄ cathodes were studied in detail. Overcharge testing of Lithium-ion cells with a systematic variation in the cell balance demonstrated that the overcharge characteristics of Lithium-ion cells was affected by the amount of cathode in the cells, which is independent of the amount of anode material. The rate of charge was found to be an important parameter, as electrolyte complete decomposition at low charge rates caused the end of overcharge testing, while high charge rates accelerated the rate of heat generation in the cells and the cell …

An Electrochemical Study Of Electroless Copper Plating Using Glyoxylic Acid As Reducing Agent, Li-Qiong Wu, Fang-Zu Yang, Ling Hang, Shi-Gang Sun, Shao-Min Zhou

Journal of Electrochemistry

The electroless copper plating using glyoxylic acid as a reducing agent,Na₂EDTA as a chelating agent and K₄FeCN₆ and 2,2'-dipyridyl as additives was studied. The effect of chelating agent and addtives on the polangation behaviovs of copper reduction and glyoxylie acid oxidation were analyzed by linear sweep voltammetry. The results mainly demonstrated that the chelating agent hindered both the oxidation of glyoxylic acid and the reduction of copper complexing ions. It has revealed that K₄FeCN₆ and 2,2'-dipyridyl (with the content over than 20 mg/L) both played negative actions on the oxidation of glyoxylic …

The Deactivation Mechanism Of Metal Oxide Anodes Under Alternative Current Electrolysis Condition, Jun-Tao Wang, Yan Han, Guang-Zhang Chen, Wen-Fa Liu

Journal of Electrochemistry

The metal oxide anodes coated on titanium used in seawater electrolysis were prepared by thermal decomposition. Their morphologies, compositions and phase structures were determined by scanning electron microscope(SEM), energy dispersive X-ray detector(EDX) and X-ray diffraction(XRD). The electrochemical properties of the anodes were characterized by accelerated life test, cyclic voltammetry and electrochemical impedance spectroscopy. SEM, EDX and XRD showed that solid solution structures of (Ru, Ir, Ti)O₂ and (Ir, Ti)O₂ were formed after pyrolysis, the solid solution structures and active components were disappeared after the deactivation of the anodes. Electrochemical results indicated that the active area decreased and the …

Copper Electrodeposition Under The Perturbation Of Hard Particles, Zeng-Wei Zhu, Di Zhu

Journal of Electrochemistry

Copper electrodepositon was carried out on the rotating cathode,with hard particles(such as ceramic beads) filling between the electrodes. The rotation of cathode led hard particles to polish and impact the surface of deposit during electrodeposition.Copper deposits with a mass of cuspidal nodules were produced in acid sulfate solutions while brittle deposits without nodules were produced in alkaline sulfate solutions. It was also found that brightening and smoothing deposit could be obtained from the alkaline solution, and the deposit was approximatively disordered orientation with granular morphology of about 100~300 nm. The results show that the polishing and impact of hard particles …

Silicides And Composites Materials As Anodes For Lithium Ion Batteries, Jun-Mei Yan, Hui-Zhen Huang, Jing Zhang, Yong Yang

Journal of Electrochemistry

The anode materials of Mg₂Si and MnSi were synthesized by mechanically activated annealing(MAA) techniques in this work and the in electrochemical performances were also studied.A series of composite materials of Mg₂Si and CNTs or CMS were prepared by ball-milling method respectively. The reversible capacities of the composites were higher than that of the pure Mg₂Si and pure carbon materials.The cyclic performances have been improved greatly by ball-milling of the Mg₂Si and carbon materials. Results show that ball-milling method is one kind of method to make alloy materials into practical use.

Electrochemical Disinfection Method To Treat Wastewater From Hospitals, Zhi-Fu Li, Ya-Dong Tan, Ning Xu, Shao-Hong Ren, Yu Zhao

Journal of Electrochemistry

Electrochemical disinfection method was used to treat wastewater from hospitals. The mechanism of electrochemical disinfection was researched by using the different anode materials. The results showed that when the titanium coated with noble metal (Ru, Pt, Ir)oxide was used as an anode and stainless steel as a cathode, the current density was 6 mA/cm², hydraulic retention time was 15 min,air flow rate was 40 L/h, the rate of anode effective area to the inner water volume was 1.0, the amount of total colibacillus was below 500 CFU/L after electrochemical disinfection,All these meet the first order of Effluent Discharge …

Electrochemical Controllable Preparation Of Hydroxyapatite Coating With Different Morphologies And Preliminary In Vitro Tests, Hai-Yan Shi, Ren Hu, Chang-Jian Lin

Journal of Electrochemistry

The Controllable electrochemical deposition has been developed to prepare the hydroxyapatite(HA) coatings on Ti substrate with different morphologies and structures. Three kinds of typical topography of HA coatings, i.e. standing-up, flower and ordered porous structures have been obtained. The XRD and FTIR results demonstrate high crystallinity of the coating and exclusion of other forms of calcium phosphates. In vitro tests reveal that the biological property is largely dependent on the structure and morphology of the HA coating. It has been found that all pure HA coating show good biocompatibilities, while only the HA coating with ordered porous structures exhibits best …

Electrochemical Oxidation Of Organic Additives In Tin Plating Electrolytes, Yin-Mei Cheng, Lan-Kun Cai, Qiang Song

Journal of Electrochemistry

Cyclic voltammetry(CV) was used to characterize the voltammetric behaviours of organic additives, e.g. PSA(phenolsulfonic acid) EN(ethoxylatedα-naphthol) and ENSA(ethoxylatedα-naphthol sulfonic acid), on the anode surface. In PSA solutions, an anodic peak was obtained and the peak potential was about 1.2V. In EN and ENSA solutions, two anodic peaks were obtained and the peak potentials were about(0.95V) and 1.3V. The products of galvanostatic electrolysis were separated by HPLC(high performance liquid chromatography) and analyzed by EI/MS(electron ionizing mass spectrometry). The mechnism of the electrochemical oxidation was also disussed.

The Electrocatalystic Investigation Of 3,4-Dihydroxybenzoic Acid On The Modified Multiply Wall Carbon Nanotubes, Ming-Qi Li, Duo-Chang Cai, Xiao-Ying He

Journal of Electrochemistry

The electrochemical behavior of 3,4-Dihydroxybenzoic acid(DHBA) on modified multiply wall carbon nanotubes electrode was investigated by cyclic voltammetry(CV) and square wave voltammetry(SWV). Results show that in 0.1 mol/L HCl solutions the modified carbon nanotube electrode has an obvious electrocatalytic effect on the oxidation and deoxidization of DHBA. The oxidation current of DHBA is linear to it's concentration in the range of 4.0×10^-6～1.0×10^-4 mol/L and 2.0×10^-4～8.0×10^-4 1mol/L with correlation coefficient of 0.9995 and 0.9992. The detection limit is 1.0×10^-6 mol/L.

Negative Spin Polarization And Large Tunneling Magnetoresistance In Epitaxial Co|Srtio3|Co Magnetic Tunnel Junctions, Julian P. Velev, Kirill D. Belashchenko, Derek A. Stewart, Mark Van Schilfgaarde, Sitaram Jaswal, Evgeny Y. Tsymbal

Materials Research Science and Engineering Center: Faculty Publications

We perform an ab initio study of spin-polarized tunneling in epitaxial Co|SrTiO₃|Co magnetic tunnel junctions with bcc Co(001) electrodes. We predict a large tunneling magnetoresistance in these junctions, originating from a mismatch in the majority- and minority-spin bands both in bulk bcc Co and at the Co|SrTiO₃ interface. The intricate complex band structure of SrTiO₃ enables efficient tunneling of the minority d electrons which causes the spin polarization of the Co|SrTiO₃ interface to be negative in agreement with experimental data. Our results indicate that epitaxial Co|SrTiO₃|Co magnetic tunnel junctions with bcc Co(001) electrodes …

Synthesis Of Fuel Cell Membrane: Copolymerization Of Styrene On Etfe Film By Grafted Pre-Irradiation, Yohan Yohan, Rifai M. Nur, Lilik Hendrajaya, E. S. Siradj

Makara Journal of Technology

Synthesis of Fuel Cell Membrane: Copolymerization of Styrene on ETFE Film by Grafted pre-Irradiation. Preirradiation Grafting styrene monomer on ETFE film has been prepared. Research has been performed by γ-ray radiation at various total dose from 2.5 – 12.5 kGy and various dose rate from 1.3 – 1.9 kGy/hour. Irradiated copolymer is then grafted by styrene monomer in various solvent: ethanol, 2-propanol, and toluene, various concentration from 20 – 70% volume, various temperature from 50 – 90oC, and various grafting time from 2 – 12 hours. The results showed that percent of grafting is increase with increase of total dose …

Design Of Product Placement Layout In Retail Shop Using Market Basket Analysis, Isti Surjandari, Annury Citra Seruni

Makara Journal of Technology

Retailing is an industry with high level of competition. It is a customer-based industry which depends on how it could be aware of what the customers’ needs and requirements are. One technique most used in supermarkets is the mix merchandise. The purpose of this paper is to identify associated products, which then grouped in mix merchandise with the use of market basket analysis. This association between products then will be applied in the design layout of the product in the supermarket. The process of identifying the related products bought together in one transaction is done by using data mining technique. …

Production Hydrogen And Nanocarbon Via Methane Decomposition Using Ni-Based Catalysts. Effect Of Acidity And Catalyst Diameter, Widodo W. Purwanto, M. Nasikin, E. Saputra, L. Song

Makara Journal of Technology

Objectives of this research are mainly to study impacts of acidity strength (by varying amount of precipitant and loading Al-Si) and the effect of nickel particle size (by varying calcinations temperature) on decomposition reaction performances. In this research, high-nickel-loaded catalyst is prepared with two methods. Ni-Cu/Al catalysts were prepared with co-precipitation method. While the Ni-Cu/Al-Si catalyst were prepared by combined co-precipitation and sol-gel method. The direct cracking of methane was performed in 8mm quartz fixed bed reactor at atmospheric pressure and 500-700°C. The main results showed that the Al content of catalyst increases with the increasing amount of precipitant. The …

Design And Implementation Of 1-2 Ghz Stepped Frequency Gpr For Buried Metal Detection, Joko Suryana, Andriyan B. Suksmono, Tati R. Mengko

Makara Journal of Technology

Design and Implementation of 1-2 GHz Stepped Frequency GPR for Buried Metal Detection. In this paper, we describe the design and realization steps of 1 – 2 GHz SFGPR (Stepped Frequency Ground Penetrating Radar) transceiver for metal detection under the ground. Before using prototyped GPR for detecting the metal under the ground, several of calibration processes must be performed, namely phase calibration and monocycle pulse waveform calibration. After completing the calibrations, this prototyped GPR would be ready for detecting a hidden object such as a metal plate 5 cm under the ground in our small test range size 25 cm …

Simultaneous Treatment Of Organic (Phenol) And Heavy Metal (Cr6+ Or Pt4+) Wastes Over Tio2, Zno-Tio2 And Cds-Tio2 Photocatalysts, Slamet Slamet, R. Arbianti, Daryanto Daryanto

Makara Journal of Technology

Simultaneous Treatment of Organic (Phenol) and Heavy Metal (Cr6+ or Pt4+) Wastes over TiO2, ZnO-TiO2 and CdS-TiO2 Photocatalysts. Treatment of heavy metal (Cr6+ and Pt4+) and organic (phenol) wastes has been studied using the relatively new method, i.e. simultaneous photocatalytic process over TiO2 photocatalysts in the batch photoreactor. Following the photocatalytic reduction of the heavy metal wastes, recovery of Cr and Pt was carried out by precipitation and leaching method, respectively. The experimental results show that in the simultaneous photocatalytic system, there is a synergism effect between the photocatalytic reduction of heavy metal waste (Cr6+ or Pt4+) and the oxidation …

Design Of Generating Dual Frequency Operation For Triangular Microstrip Antenna Using Electromagnetic Coupling, Indra Surjati, Eko Tjipto Rahardjo, Djoko Hartanto

Makara Journal of Technology

Design of Generating Dual Frequency Operation for Triangular Microstrip Antenna Using Electromagnetic Coupling. A new design is proposed in this paper by applying a pair of slits using a microstrip feed line. Therefore the microstrip line feeding system is electromagnetically coupled to the patch. The antenna works at two different frequencies in the range from 2 GHz to 4 GHz (S band frequency). The results of the simulation shows that the dual frequency operation can be created when the slit width is 1 mm and the height of the slits ranges from 10 mm to 14 mm with inter slit …

Development Of Low Frequency Vibration Method Of Direct-Write Deposition Relevant To Layer Manufacturing Application, Susilo Adi Widyanto, Alva Edy Tontowi, Jamasri Jamasri, Heru Santosa Budi Rochardjo

Makara Journal of Technology

The research of deposition process is the first step in development process of multi materials selective laser sintering. The deposition process enables to settle multi materials powder in horizontal formation on one layer. In this research we use low frequency (70 - 200Hz) to vibrate a hopper nozzle in which powder is settled. The research method consists of two steps, the first step is to determine flow-ability parameters and the second is to join flow ability parameter with other parameters such that the line width can be controlled. The results show that the line width depends on uniformity of particle …

High Temperature Heat Exchanger Project: Quarterly Progress Report July 1, 2005 Through September 30, 2005, Anthony Hechanova

Publications (NSTD)

Quarterly Collaboration Meeting. The University of California, Berkeley, hosted a UNLVRF HTHX Project quarterly meeting on September 12. The purpose of the meeting was to promote collaboration and communication among the UNLV Research Foundation partners. Collaborators discussed their research program plan and provided an update on their progress. The next meeting will be in December in Las Vegas, NV hosted by UNLV.