Materials Science and Engineering Commons^™

Pure Hap Film Prepared By Direct Electrodepositing On Metallic Surface And Its Mechanism, Hao-Bing Hu, Chang-Jian Lin, Fei Chen, Ren Hu, Ming Guo

Journal of Electrochemistry

In controlling concentration of Ca²⁺ and PO₄^3- in electrodeposition solution, the HAP film on Ti alloy has been deposited directly. Using XRD and SEM we have learned that prepared HAP is intact in crystal and equal in dimension. Thermodynamic calculation indicated that the HAP is easer formation of than that TCP of. With the XRD, SEM analyses and thermodynamic calculation, the electrodeposition mechanism has been discussed. It was proved that electrodepositon is a two-stage process and formation of HAP is a direct process from solution ions to HAP crystal without precursor.

Synthesis And Characterization Of Lini0.8-XAlXCo0.2O2 As Cathodes For Lithium-Ion Batteries, Jun Zhang, Zhong-Kao Jin, Qing-He Yang, Qing-Mei Song, Xiao-Hua Ma, Xiang-Fu Zong

Journal of Electrochemistry

Single-phase solid solution of LiNi_0.8-xAl_xCo_0.2O₂ (0≤ x <0.1)had been synthesized and characterized by X-ray diffraction(XRD) and scanning electron microscopy (SEM). Their electrochemical performance was examined by charge-discharge cycling. The LiNi_0.71Al_0.09Co_0.2O₂ compound showed a discharge capacity of 152 mAh/g after 20 cycles that corresponds to 97.4% capacity retention. The beneficial effect of co-doping with Al and Co elements was corro-borated by slow scanning cyclic voltammograms(SSCV), electrochemical impedance spectrum (EIS) and differential scanning calorimetry (DSC) data on charged cathodes. These results show that the 2D-character of the crystal lattice was stabilized by co-doping with Al and Co, the phase transitions that occur during deintercalation or intercalation of Li-ions were significantly suppressed, …

Diffusion Of Hydrogen At Iron Apply For Electrochemical Oscillating Permeation, Li Zhang, Ren-He Yin, Zhan-Mei Sun

Journal of Electrochemistry

The diffusion of hydrogen in iron was measured using electrochemical oscillating permeation. Through the samples in the different frequencies, it was found that diffusion of hydrogen at iron is of linear relation with boundary condition, which is the key to Fick's diffusion equation amplitude in the liquor. We can exploit this line relation getting the diffusion of hydrogen at iron.

Research Progress On Electrode Material In All-Vanadium Redox Battery, Hua Li, Shou-Wen Chang, Chuan-Wei Yan

Journal of Electrochemistry

An all-vanadium redox flow storage battery possesses many advantages over conventional storage batteries.The development statue of two types electrode materials (metal and compound type) is introduced in this article.

Optimum Of Catalyst Layers For Direct Methanol Fuel Cells, Jun Zhang, Lei Li, Li Xu, Yu-Xin Wang

Journal of Electrochemistry

The performances of membrane electrode assemblies (MEAs)with various Pt loading were compared. The amount of Nafion in a catalytic layer was optimized, and the effect of Nafion loading on the resistance of MEAs was investigated with ac impedance spectroscopy. For a MEA with both Pt 4 mg/cm² in the anode and the cathode, suitable Nafion loading was 21.4 wt% in the anode. With 21.4 wt% Nafion loading in the cathode, the Direct Methanol Fuel Cells(DMFC) showed the highest performance at high current density. While, the DMFC performances came down, as Nafion loading increasing,for ohm and concentration polarization.

Electrochemical Properties Of Nitrate Immobilized On Gold Electrodes With 2-Aminoethanethiol Sams, Ya-Ru Song, Hong Wu, Hui-Bo Shao

Journal of Electrochemistry

Nitrate reductase (NR) and phospholipids were immobilized on gold electrodes with 2-aminoethanethio(AET) SAMs. After Au/AET/NR and Au/AET/NR/lipid were soaked in pH 7 phosphate buffers for days, a pair of pre-reversible peak appeared at around 0.202 V and 0.149 V respsctively, irregularly grew with soaking time in blank buffer.The cathodic peak current (i_pcl) of Au/AET/NR system had linear relationship with scan rate between 0.02 and 0.5 V⋅s^-1 ,while i_pcl was proportional to V^1/2 in Au/AET/NR/lipid system. The direct electron transfer of enzyme electrodes was strongly affected by pH. Compared with Au/AET, NR exhibited a higher electrochemical …

Modification Of Molybdenum Nitride Electrode For Supercapacitor(I)——The Effect Of Ammonium Vanadate On The Properties Of Molybdenum Nitride Electrode, Xue-Liang Li, Dao-Rong Luo, Hua-Lin Wang, Jian-Bo He, Yun-Guei Zhu

Journal of Electrochemistry

The effect of vanadium on the properties of the electrode of molybdenum nitride has been studied by using XRD, SEM and cyclic voltammetry. Modified molybdenum nitride was made as follow: films were coated by dipping titanium sheet in the solution containing different composition of molybdenum oxide, ammonium vanadate, ammonia, glycol and oxalic acid, and coated films are reacted with free ammonia. The results show that the specific capacitance of modified electrode was considerably increased and the operation voltage was broadened with the addition of ammonium vanadate in the dipping solution. The mechanism of these effects generated is the formation of …

Dielectric Properties Of A Ferroelectric Copolymer Langmuir–Blodgett Film, Mahantappa S. Jogad, Stephen Ducharme

Stephen Ducharme Publications

We report measurements of the real (epsilon prime) and imaginary (epsilon double-prime) parts of the relative complex permittivity of a Langmuir–Blodgett film of ferroelectric copolymer of vinylidene fluoride (70%) with trifluoroethylene (30%). The measurements were made in the temperature range of 35 to 125° C, and frequency range of 19 Hz to 5 MHz. The results indicate low frequency loss due to conduction and dielectric loss peak near the ferroelectric–paraelectric phase transition.

Electrically-Small Low Q Radiator Structure And Method Of Producing Em Waves Therewith, Craig A. Grimes, Dale M. Grimes, Faton Tefiku, Gang Lui

Chemical and Materials Engineering Faculty Patents

An electrically small radiator structure for radiating electromagnetic waves having an electrical size, k*a, with a value less than π/2 and above π/20,000 and configured to have at least a first and second magnetic, or electric, dipole element. Dipole elements are preferably oriented such that a source-associated standing energy value for the structure, or W_ds(t_R), is low, Radiative Q value preferably less than ⅓(k*a)³; and each of the elements, whether paired with respective electric dipole elements, is in electrical communication through a feed circuit to at least one power source. Further, a first …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 5/16/02- 8/15/02, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

An important aspect of the Advanced Accelerator Applications (AAA) program is the development of a casting process by which volatile actinide element (i.e., americium) can be incorporated into metallic alloy fuel pins. The traditional metal fuel casting process uses an inductively heated crucible.

This process works well for the fabrication of metal fuel pins traditionally composed of alloys of uranium and plutonium, but does not work well when highly volatile actinides are included in the melt. The problem occurs both during the extended time period required to superheat the alloy melt as well as when the chamber must be evacuated. …

System Integration And Real-Time Control Architecture Of A Laser Aided Manufacturing Process, Mallikharjuna R. Boddu, Robert G. Landers, Srinivas Musti, Sanjeev Agarwal, Jianzhong Ruan, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper discusses a hybrid deposition–removal manufacturing system being developed at the University of Missouri--Rolla. The system consists of a laser system, five-axis CNC machining center, and powder feeder system. A description of the control software, real-time control architecture, and integration of various subsystems to build the hybrid system is given. The interaction of the real-time controller with various sensors and subsystems to monitor and regulate the process is presented. The communication between integrated process planning for the system and real–time control is also discussed in this paper.

The Effects Of Corrosive Chemicals On Corrosion Rate Of Steel Reinforcement Bars: I. Swamp Water, Sulistyoweni Widanarko, Henki W. Ashadi, Andri Krisnadi Wicaksono

Makara Journal of Technology

Most of infrastructures using steel concrete to reinforce the strength of concrete. Steel concrete is so vulnerable to chemical compounds that can cause corrosion. It can happen due to the presence of chemical compounds in acid environment in low pH level. These chemical compounds are SO4 2-, Cl-, NO3 -. There are many swamp area in Indonesia. The acid contents and the concentration of ion sulphate, chlorides, and nitrate are higher in the swamp water than in the ground water .The objective of this research was to find out the influence of corrosive chemicals in the swamp water to the …

The Effects Of Corrosive Chemicals On Corrosion Rate Of Steel Reinforcement Bars: Ii. Swamp Sludges, Henki W. Ashadi, Sulistyoweni Widanarko, Irma Gusniani

Makara Journal of Technology

A polluted environment will influence the building age. The objective of this research was to find out the influence of corrosive chemicals within the sludge swamp area with the corrosion rate of steel concrete. Corrosion in steel concrete usually occur in acid area which contain of SO4 2-, Cl- and NO3 -. The research treatment used by emerging ST 37 and ST 60 within 60 days in ‘polluted’ sludge swamp area. Three variation of ‘polluted’ swamp sludge were made by increasing the concentration a corrosive unsure up to 1X, 5X and 10X. The corrosion rate measured by using an Immersion …

The Effect Of Ca Content On Cao-Zeolite On Nitrogen Adsorption Capacity, Mohammad Nasikin, Tania Surya Utami, Agustina Tp Siahaan

Makara Journal of Technology

In industry, Ca zeolite is used as nitrogen selective adsorbent with the use of PSA (Pressure Swing Adsorption)/VSA (Vacuum Swing Adsorption) methods. Natural zeolite modified to be Cao-zeolite by ion exchange process using Ca(OH)2. Adsorption test was done on CaO-zeolite with different Ca concentration to understand how it’s adsorption phenomena on oxygen and nitrogen. Adsorption test has been done for CaO-zeolite with Ca concentration = 0,682%, 0,849% and 1,244% to oxygen and nitrogen with equal concentration seperately. Pressure variation has being done three times (5 minutes long each time) adsorption time to analyze the connection between adsorption time and how …

Cetane Number Booster Additive For Diesel Fuel Synthesized From Coconut Oil, Mohammad Nasikin, Rita Arbianti, Abdul Azis

Makara Journal of Technology

To reduce NOx, SOx, HC, and particulates that produce because of using diesel fuel, can be done by increasing cetane number. One of methods is adding an additive to diesel fuel. 2-Ethyl Hexyl Nitrate (2-EHN) is a commercial additive that an organic nitrate. Making an additive in this research is used palm oil by nitration reaction that used HNO3 and H2SO4. Result of this reaction is methyl ester nitrate that has a structure looks like 2-EHN. IR spectra from research show that methyl ester nitrate is indicated by spectrum NO2 at 1635 cm-1. This result show that methyl ester nitrate …

Analogy Method Development For Cost Estimation Of Software Design, Riyanarto Sarno, Joko Lianto Buliali, Siti Maimunah

Makara Journal of Technology

The important aspect of planning and managing software development project is to estimate the cost of a project. There are several methods for estimating the cost of a software development project, and the Analogy method is a method which gives relatively better estimates. This paper shows that the modified Analogy method selects a closer project reference, estimates more accurate project effort and cost. This study enhances the cost estimate technique by including valid and complete cost parameters, therefore the estimate of a project cost is better than the result of the standard Analogy method.

The Role Of Si3n4 Amorphous Phase In Nc-Tin/A-Si3n4 Nanocomposites In Increases The Hardness And Thermal Stability, Keba Moto

Makara Journal of Technology

The role of Si3N4 amorphous phase in nc-TiN/a-Si3N4 nanocomposites will be shown and compared with polycrystalline ZrN/Ni which has no such amorphous phase (non-composites). The presence of amorphous phase Si3N4 increases the hardness of film as well as the toughness of the bulk nanocomposites under indentation load. It has been observed that nc-TiN/a-Si3N4 nanocomposites films has higher thermal stability than ZrN/Ni polycrystalline films.

Biodiesel's Characteristics Preparation From Palm Oil, Tilani Hamid. S, Rachman Yusuf

Makara Journal of Technology

Biodiesel’s characteristics preparation from palm oil. Using vegetable oils directly as an alternative diesel fuel has presented engine problems. The problems have been attributed to high viscosity of vegetable oil that causes the poor atomization of fuel in the injector system and pruduces uncomplete combustion. Therefore, it is necessary to convert the vegetable oil into ester (metil ester) by tranesterification process to decrease its viscosity. In this research has made biodiesel by reaction of palm oil and methanol using lye (NaOH) as catalyst with operation conditions: constant temperature at 60 oC in atmosferic pressure, palm oil : methanol volume ratio …

Development Of Hardness Measurement Procedure For Nanocomposite Nc-Tin/A-Si3n4, Keba Moto

Makara Journal of Technology

Hardness of nc-TiN/a-Si3N4 nanocomposites which was determined by using two methods of measurements i. e. depth sensing method and remaining plastic indentation area that were magnified by using SEM (Scanning Electron Microscope) lie in the good agreement. The hardness value is not influenced by the biaxial and residual compressive stress. The measurement of the biaxial stress on the substrate shows a very small value of biaxial stress as well as the constant hardness and crystallite size against annealing temperature. Therefore, the reported hardness value here is the intrinsic value that depend on its microstructure properties.

Correlation Between The Xps Peak Shapes Of Y1bu2cu3o7-X And Film Quality, Paul N. Barnes, Sharmila M. Mukhopadhyay, Timothy J. Haugan, Swaminathan Krishnaswami, Justin C. Tolliver, Iman Maartense

Mechanical and Materials Engineering Faculty Publications

X-ray photoelectron spectroscopy (XPS) depth profiling was used to investigate the compositional and chemical profile of a typical YBCO coated conductor architecture. Results of the process revealed that the Y(3d) photoelectronic peak shape in these films is very different from bulk YBCO. To investigate this, several samples of Y i Ba2Cu307_„ thin films were intentionally created of varying quality. The films were deposited on LaA10 3 by pulsed laser deposition with ./c. values ranging from poorly conducting up to several MA/cm2. Initial results indicated a potential correlation between the Y(3d) XPS peak shape (full-width-half-maximum) of the YBCO and the film …

Surface Switching Characteristics Of Variable Permittivity Dielectrics, Wayne Huebner, Eric J. Carleton

Materials Science and Engineering Faculty Research & Creative Works

Flashover voltage, lifetimes, and switch performance of insulators utilizing square thin and thick film electrodes were examined to determine the viability of using thin electrodes for reliable surface discharge switching. Gold, silver, and platinum were sputtered (0.25 µm) and screen printed (15 µm) onto Al₂O₃, TiO₂, and modified BaTiO₃ (MBT), then tested in air at 10⁵ Pa, under vacuum (10^-3/ torr), and while immersed in an insulating fluid, SF-2 (manufactured by 3M). For the measured range of 0.5 to 3 mm in air, the flashover voltage for all three insulators …

Corrosion Of Steel By Lead Bismuth Eutectic: Quarterly Report For May-June-July 2002, John Farley

Transmutation Sciences Materials (TRP)

The goal of this project is to understand the basic science of corrosion in the steel/LBE system.

We are taking more data, typically using the newly installed X-ray Photoelectron Spectrometry (XPS) apparatus, and analyzing our existing data. Undergraduate students Denise Parsons and Julia Manzerova have helped a great deal in the analysis of the data. We can obtain the elemental composition as a function of position within the sample. This gives clues to the migration of materials, the composition of the protective oxide layer, and the basic science of the corrosion process. We found dramatic differences between the exposed and …

Modeling And Simulation Of The Chemical Etching Process In Niobium Cavities, Qin Xue

UNLV Theses, Dissertations, Professional Papers, and Capstones

Niobium Cavities are important parts of the integrated NC/SC high-power linear accelerator (linac) that can accelerate over 100 mA of protons to several GeV. Surface finish of the niobium cavity plays an important role of achieving the best performance of niobium cavity. The chemical etching techniques have been widely used.

Chemical etching of the inner surface of the cavity is achieved by circulating acid through it. The acid interacts with the surface and eliminates imperfections. During the etching process, a pipe with baffles is inserted within the cavity to direct the flow along the surfaces.

A 2-D, axisymmetric, steady state, …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides, Xiaolong Wu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fundamental issues related to the selection of a metallic fuel casting furnace design are presented and discussed including heating mechanisms, casting issues, crucible design, and issues related to the mass transport of americium. The process of evaluating all of these different criteria is undertaken to select a concept that would have the greatest chance of success for casting americium in a metallic fuel rod. Based on this evaluation process, a concept for the casting of metallic fuel pins containing high vapor pressure materials is selected and discussed. The important physics of this concept include mass transport of americium from the …

44th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 44th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Denver, Colorado, July 28 - August 1, 2002.

Raman Scattering And Lattice Defects In Nanocrystalline Ceo2 Thin Films, Igor Kosacki, Toshio Suzuki, Harlan U. Anderson, Philippe Colomban

Materials Science and Engineering Faculty Research & Creative Works

The results of Raman scattering studies of nanocrystalline CeO₂ thin films are presented. The spectra have been described using the spatial correlation model from which the correlation length has been determined as a function of grain size. A direct comparison between the concentration of defects related to correlation length and CeO₂ non-stoichiometry has been achieved. The relationship between the lattice disorder and the form of the Raman spectra in nanocrystalline CeO₂ is discussed. © 2002 Elsevier Science B.V. All rights reserved.

Study Of Non-Equilibrium Electron Dynamics In Metals, Wael Mohamed Gomaa Ibrahim

Electrical & Computer Engineering Theses & Dissertations

Thermal phenomena, such as heat propagation, lattice melting, and ablation, are the result of energy deposition in metals. A fundamental understanding of the electron dynamics leading to these thermal phenomena would benefit many laser applications, such as laser deposition of thin films and laser processing.

In this work, thin metal films were prepared using the resistive heating evaporation technique. High dynamic range autocorrelators were constructed to characterize the different laser systems used in this study. The nonequilibrium electron dynamics in single layer gold films, multi-layer gold-vanadium, and gold-titanium films were studied. The time evolution of the electron temperature was monitored …

Evaluation Of Corrosion Inhibitor On Pre-Corroded Carbon Steel In Co2 Medium By Impedance Spectroscopy, Joseph Buchweishaija

Tanzania Journal of Engineering and Technology (TJET)

The effect of pre-corrosion of carbon steel on the performance of a commercial amine based fatty acid corrosion inhibitor, KI384, was investigated in formation water solutions saturated with CO₂ using electrochemical impedance spectroscopy (EIS) measurements. The investigation was performed at constant partial pressure of CO₂ using an autoclave system with Rotating Cylinder Electrodes (RCE). Carbon steel was pre-corroded for periods up to 7 days at 35 and 80 °C in the test solution prior to inhibitor injection. The results showed that when KI384 was applied on non-corroded carbon steel specimen, high inhibitor performance (99.8 %) was achieved independent of temperature. …

Investigation Of Forces Acting On Plain Discs, S. M. Mpanduji

Tanzania Journal of Engineering and Technology (TJET)

An investigation was carried out to study the mutually perpendicular forces generated by rotating and non-rotating plain discs similar to those used in disc ploughs. Experiments were conducted in a soil bin containing sand loam soil (Ryton sand) where forces were measured while changing disc rake and sweep angles. The results showed that draught forces were higher for non-rotating discs, while vertical and lateral forces were lower compared to rotating discs. Rotating discs were found to be suitable for counteracting high side forces because of less draught and higher lateral forces. The recommended optimum angles are between 8°–12° for disc …

Requirements Of A Sustainable Pavement Management System For Tanzania, N. K.M. Mushule

Tanzania Journal of Engineering and Technology (TJET)

Since the introduction of pavement management concepts in mid-1960s, more than three decades ago, a considerable number of Pavement Management Systems (PMS) have been developed and implemented widely in many parts of the world. These systems differ in scope and sophistication. However, in some cases, pavement management systems have fallen into marginal use, if not into complete disuse, because of a number of reasons. One of the major reasons leading to the marginalisation or abandonment of pavement management systems, is the failure of system developers to recognise specific and unique needs of the agency or authority responsible for road management. …