Materials Science and Engineering Commons^™

Modeling, Fabrication, And Optimization Of Niobium Cavities: Phase Iii Third Quarterly Report, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Niobium cavities are important parts of the integrated NC/SC high-power linacs. Over the years, researchers in several countries have tested various cavity shapes. They concluded that elliptically shaped cells are the most appropriate shape for superconducting cavities. The need for very clean surfaces lead to the use of a buffered chemical polishing produce for surface cleaning to get good performance of the cavities. The third phase concludes the experimental a fluid flow study and optimization study. The first quarter and second quarter of phase three also begins the experimental set-up of secondary emission studies from niobium in superconducting mode. This …

Progress In Research For Biofuel Cell, Yue Bao, Xia-Qin Wu

Journal of Electrochemistry

In this article, research progresses of the biofuel cell in recent years were summarized. The operation principle and classification of the biofuel cells were described. The role of the mediator for promoting electron transfer in biofuel cells and the techniques for improving the electric properties of biofuel cells, such as output potential, were discussed with some attracting research instances. Finally, the choke points for research of biofuel cell were explored, and the application prospect of biofuel cells was forecasted.

Preparation, Structure And Electrochemical Hydrogenation Of Carbon Nanotubes Supported Platinum Catalysts, Qing-Gang He, Xiao-Zi Yuan, Xian-Xia Yuan, Zi-Feng Ma

Journal of Electrochemistry

In this paper, Pt/CNTs catalyst was prepared and its electrocatalytic property was studied by obtaining cycling voltammetry curves (C-V) and Tafel curves. In addition, the XRD,XPS and TEM tests were carried out to determine the structure and composition of the catalysts. It can be found that the platinum loading has been increased significantly using a carbon nanotubes support. Dispersion of Platinum was better and gave more active sites. The electrochemical characteristic of Pt/CNTs was also more desirable than that of Pt/C catalys t(Johnson Matthey). In conclusion, carbon nanotubes can played a conspicuous role in "electrogenerative" processes of PEMFC hydrogenation reactor.

The Interaction In Doping Lithium Of Carbonaneous Anode In Lithium Ion Battery, Chang-Guo Chen, Hong-Min Zhang, Jia Chen, Dan-Mei Yu

Journal of Electrochemistry

The quantum chemical DV-X_α method was used to calculate the lithium-doped models from one-Li-dopant to LiC₆ and LiC₂. It was found that Li⁺ has an tendency to attract electrons from the carbon plane through the C₆ hexagons lying above or below it by the graph of charge-density difference. It was shown that LiC₆ can exist steadily,while LiC₂ can not exist steadily.

Study On Determination Of Iodine Ion At Chitosan Modified Glassy Carbon Electrode, Bin Liu, Xiang-Ying Sun, Jin-Rui Xu

Journal of Electrochemistry

In this paper, a chitosan modified glassy carbon electrode was prepared by the method of covalent-bond reaction, and the anodic stripping voltammetric characteristics of iodine on the modified electrode was studied. The results showed that the modified electrode has higher adsorption and selectivity for I^- , and the sensitivity for I^-  has been much improved in 0.1 mol·L^-1 KH₂PO₄ solution (pH=4.0). The anodic stripping peak current of I^- on the modified electrode varied linearly with I^-  concentration in the range of 2.0×10^-6～2.0×10^-3 mol·L^-1, and the detection limit …

Electrochemical Synthesis Of Ferrate(Vi) By Anodic Oxidation, Jia-Ju Xu, Jian-Ming Wang, Wei-Hua Yang, Cheng Chen, Jian-Qing Zhang

Journal of Electrochemistry

The ferrate(Ⅵ) was synthesized by electrochemical anodic oxidation. The effects of preparation conditions on the current yield of ferrate(VI) synthesis have been studied in this work. The experimental results showed that grey cast iron as an anodic material is suitable for electrochemical synthesis and NaOH solution as an electrolyte results in a higher current yield than KOH solution. The highest current yield was obtained at a current density (4.54) mA·cm^-2, temperature 20 ℃ and 14 mol·dm^-3 NaOH. In this case, a current yield of 68.5% was obtained by electrolysis for 1 h.

Studies On The Mechanism Of Electroreduction Of Oxalic Acid, Yu-Zhan Li, Xin Liu, Rui-Sheng Hu, Deng-Ping Gu

Journal of Electrochemistry

The electroreduction mechanism of oxalic acid on Pb electrode in Na₂SO₄ solution were investigated using high scan rate cyclic voltammetry and chronoamperometry. The dynamic parameters for the first step electron transter reaction of oxalic acid electroreduction by were determined. The corresponding reduction peak potentials of oxalic acid, glyoxylic acid and glycolic acid in the cyclic voltammogranis obtained in the same condition were compared, and the intermediate reduction products of oxalic acid were suggested. The results showed that oxalic acid is weakly absorbed on the lead electrode.

Template Synthesis Of Highly Ordered Monocrystalline Metal Nanowire Arrays By A Two-Step Ac Electrodeposition, Juan Xiang, Jing-Hua Tian, Zi-Mian Ni, Zhi-Feng Huang, Bo Liu, Zhong-Qun Tian

Journal of Electrochemistry

The monocrystalline metal nanowire arrays were prepared by using a two-step AC electrodeposition in porous anodic aluminum oxide (AAO) template. The growth mechanism of nanowires was discussed. As a result, it has been found that the second voltage pulse has a considerable effect on the pore-filling ratio, the uniformity and the crystal structure, whereas the initial voltage pulse affects only the pore-filling ratio. Using the two-step AC electrodeposition, a highly ordered monocrystalline metal nanowire arrays with a pore-filling ration above 95% can be easily obtained.

Electrochemical Character Of Water Containing Gel Electrolyte And Its Preliminary Examination In Lithium Water Cell, Jing-Dong Liu, Wen-Ji Wang, Xin-Zheng Yi

Journal of Electrochemistry

AC impedance technique has been used to characterize the system of poly(methyl acrylic acid)-poly(methyl acrylic lithiumate)-glycerol (referred to as GPE).The results showed that the conductivity of GPE increased with increasing both temperature and its water content.The glass transition temperature of GPE polymer could be lowered by water. Its conducting characteristic was just like liquid electrolyte,The electrolysis of GPE was almost the same as the electrolysis of water. Its composition voltage was about 1.50V. The GPE has been used to manufacture lithium water cell. When the graphite was used as cathode, the cell could discharge continuously for 2 hours under constant …

Modeling, Fabrication, And Optimization Of Niobium Cavities: Phase Iii Second Quarterly Report, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Niobium cavities are important parts of the integrated NC/SC high-power linacs. Over the years, researchers in several countries have tested various cavity shapes. They concluded that elliptically shaped cells are the most appropriate shape for superconducting cavities. The need for very clean surfaces lead to the use of a buffered chemical polishing produce for surface cleaning to get good performance of the cavities. The third phase concludes the experimental a fluid flow study and optimization study. The first quarter and second quarter of phase three also begins the experimental set-up of secondary emission studies from niobium in superconducting mode. This …

Modeling, Fabrication, And Optimization Of Niobium Cavities, Robert A. Schill Jr., Mohamed Trabia, William Culbreth

Transmutation Sciences Materials (TRP)

One of the key technologies for the deployment of acceleratordriven transmutation systems is the accelerator itself. Elliptical superconducting niobium cavities are used to increase the efficiency of the high-power accelerators needed to support the transmutation mission.

One of the major sources of energy loss from a superconducting accelerator cavity is a process known as multiple impacting (or “multipacting”) of electrons. This phenomenon limits the maximum amount of energy and power that the niobium cavity can store. As a result, the maximum power available for accelerating the desired charge, as well as the overall performance of the accelerator is reduced. Furthermore, …

Exploration Of Artificial Multiferroic Thin-Film Heterostructures Using Composition Spreads, K.-S. Chang, M. A. Aronova, C.-L. Lin, M. Murakami, M.-H. Yu, Jason R. Hattrick-Simpers, O. O. Famodu, S. Y. Lee, R. Ramesh, M. Wuttig, I. Takeuchi, C. Gao, L. A. Bendersky

Faculty Publications

We have fabricated a series of composition spreads consisting of ferroelectric BaTiO₃ and piezomagnetic CoFe₂O₄ layers of varying thicknesses modulated at nanometer level in order to explore artificial magnetoelectricthin-film heterostructures. Scanning microwavemicroscopy and scanning superconducting quantum interference device microscopy were used to map the dielectric and magnetic properties as a function of continuously changing average composition across the spreads, respectively. Compositions in the middle of the spreads were found to exhibit ferromagnetism while displaying a dielectric constant as high as ≈120.

Alum And Pacl Coagulation, Winarni Winarni

Makara Journal of Technology

Alum and PACl Coagulation. Coagulation occurs by interaction of aluminum hydrolysis products with the contaminant such as colloidal particles. It is necessary to consider the different aluminum species that may present during specific conditions, since the mechanism of turbidity removal is dependent upon them. PACl consists of preformed aluminum hydrolysis products, which are stable below pH 6 and less sensitive than in situ hydrolysis product, alum. The benefits of PACl relative to alum have been investigated as a function of pH and Al dosages. Specific conditions and aluminum species that exist during the certain mechanisms of coagulation are discussed. Results …

The Selection Of Materials For Roller Chains From The Perspective Of Manufacturing Process, Rahmat Saptono

Makara Journal of Technology

The selection of materials for an engineering component is not only requested by its design function and shape, but also the sequence through which it is manufactured. The manufacturing operation of roller chains involves drawing and trimming processes aimed at producing semi-finished chain drives component with a well-standardized dimension. In addition to final combination of properties required by design constraints, the ability of materials to be formed into a desired shape and geometry without failure is also critical. The objective of materials selection should therefore involve additional attributes that are not typically accommodated by the standard procedure of materials selection. …

Adoption Of Variable Rate Technology, Isti Surjandari, Marvin T. Batte

Makara Journal of Technology

Site Specific Management (SSM), which also variously referred to as Variable Rate Technology (VRT), is an emerging technology that enables producers to make more precise input application decisions based on soil and field characteristics. This study analyzes factors influencing the adoption of VRT for fertilizer application for cash grain production in Ohio. Results show that producer and field characteristics might influence the adoption decision on various SSM components differently. It also provides insight as to the sequence of adoption of SSM component technologies and how this sequence might differ for producers of differing characteristics.

Study On Electrochromic Effect Of Polyaniline Film, Lienda Handojo, Junus Simangunsong

Makara Journal of Technology

Study on Electrochromic Effect of Polyaniline Film. The light transmission factor of an electrochromic film changes reversibly with the application of an electrical voltage. Thereby the transparent film becomes reversibly opaque so that it may be used to control light transmission. In this paper the results of a study on polyaniline film as an electrochromic active material is reported. Polyaniline looks yellow transparent in the reduced state and turns to green-blue at its oxidized state. The electrochromic device considered in this paper was fabricated in planar configuration of ITO glass − polyaniline film − electrolyte − ITO glass which involved …

An Economic Analysis Of Variable Rate Technology, Isti Surjandari, Marvin T. Batte, Mario J. Miranda

Makara Journal of Technology

Variable Rate Technology (VRT) offers an opportunity to improve production efficiency by allowing input applications to fluctuate in response to spatial variations in soil characteristics and nutrient levels. Society may also benefit from reduced negative externalities, such as surface and groundwater contamination, from input applications. Using a dynamic spatial model, this study examines how the interaction among variability, spatial autocorrelation, and mean level of soil fertility affects optimal sampling density and the economic gains from VRT. VRT was found to be profitable under selected conditions, and the optimal grid size will vary with these conditions. In the case where variability …

Application Of Tabu Search Algorithm In Job Shop Scheduling, Betrianis Betrianis, Putu Teguh Aryawan

Makara Journal of Technology

Application of Tabu Search Algorithm in Job Shop Scheduling. Tabu Search is one of local search methods which is used to solve the combinatorial optimization problem. This method aimed is to make the searching process of the best solution in a complex combinatorial optimization problem(np hard), ex : job shop scheduling problem, became more effective, in a less computational time but with no guarantee to optimum solution.In this paper, tabu search is used to solve the job shop scheduling problem consists of 3 (three) cases, which is ordering package of September, October and November with objective of minimizing makespan (Cmax). …

Role Of K3-Xhxpw12o40 As A Catalyst In Selective Catalysis Of Methylamine Synthesis From Ammonia And Methanol, Mohammad Nasikin

Makara Journal of Technology

Role of K3-xHxPW12O40 as a Catalyst in Selective Catalysis of Methylamine Synthesis from Ammonia and Methanol. Synthesize of methylamine from methanol and ammonia was studied in this research work using a partially potassium heteropoly salt (K3-xHxPW12O40 abbreviated as KPW) as a catalyst. KPW was prepared from heteropoly salt and potassium carbonate by using ion exchange method. The reaction was conducted at 600 ~ 800K and at the atmospheric pressure. Reactor used was a continue flow reactor with W/F=0,1~0,9g-kat.mnt./cc.Concentration of reactants and products were analyzed by gas chromathography while catalyst structure was observed by XRD (X-ray diffraction). Isothermal adsorption method was …

Identification Of The First Limiting Amino Acid In Cooked Polished White Rice Fed To Weanling Holtzman Rats, Mellova Masrizal, J. B. Lamb

Makara Journal of Technology

Forty-eight male weanling rats (91 g) were utilized to study the nutritional adequacy of cooked polished white rice. Rats were individually housed, and allowed ad libitum access to one of six treatment diets. Treatment diets were 1) polished white rice plus 10% casein and 0.18% methionine, CAS, 2) polished white rice, WHR, 3) polished white rice plus 0.45% lysine, LYS, 4) polished white rice plus0.40% methionine, MET, 5) polished white rice plus 0.30% threonine, THR, 6) polished white rice plus 0.45% lysine, 0.40% methionine, and 0.40% threonine, COM. Rice was cooked prior diet formulation using a 3 to 1 ratio …

Preparation And Characterization Of Y-Type Carbon Nanotubes By Using Anodized Alumina Oxide (Aao) Template, Jing Zhang, Quan-Yong Gao, Yong Yang

Journal of Electrochemistry

In this work, potential-modulation method was used in two-step anodization process to make an AAO template with Y-type nanochannels. Then Y-type carbon nanotubes with controlled length and branch angle were prepared in the template based on chemical vapor decomposion (CVD) method with Co particles as catalyst and C₂H₂ as carbon source. The Y-type nanotube branches exhibit the angle distribution ranging from 20° to 120°. The results demonstrated that the oxidation potential should be responsible for the angles and length of the branches. Short pulse and high oxidation potential will result in the short and dense nanotube branches.

Study On The Gas Generation In Different Charging Voltage During Formation Process In Polymer Lithium-Ion Battery, Li Huang, Ming-Gang Jin, Hui-Qun Cai, Ming-Sen Zheng, Quan-Feng Dong, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

The gases of polymer lithium-ion battery (PLI) generated under different voltages during the first charging process were examined by means of gas chromatography (GC), and the mechanism of the gas generation was discussed. The electrolyte used in batteries was 1 mol/L LiPF₆-EC～DMC～EMC=1∶1∶1(in volume). The results showed that when the charging voltage is less than 2.5 V,  the main component of generated gases are H₂ and CO₂, and when the charging voltage is 2.5 V, EC begins to decompose. Due to the decomposition of EC, the main generated gas is C₂H₄ when the …

Application Of Hydrogen-Storage Alloy Electrode In Electrochemical Reduction Of Glucose, Hui Chen, You-Gen Tang, Zheng Tang

Journal of Electrochemistry

Electrolysis of glucose was performed at constant potential using hydrogen-storage alloy as catalytic reduction electrode. It was found that the superficial treatment and activation of hydrogen-storage alloy powder had obvious effects on improving the current efficiency of sorbitol. Under the optimums, current efficiency of sorbitol by electrolyzing glucose was over 94%. The yield of sorbitol was over 80%, the lifespan of electrode was tested and analyzed, the ways of regeneration were discussed.

The Current Fluctuations Of Carbon Steel In Nano2-Nacl Solutions, Yu-Ming Tang, Yu Zuo

Journal of Electrochemistry

The characteristics of current fluctuations of A3 carbon steel in NaNO₂-NaCl solutions were studied with potentiostatic and potentiodynamic polarization methods. The steel remained stable passivation in 0.1 mol/L NaNO₂ solution without Cl^-. After NaCl was added in to the solution, current fluctuations with a characteristic of quick increase and slow decrease occurred, indicating quick dissolution and slow re-passivation of the metastable pits. The metastable pitting may cause accumulated corrosion damage around certain area and result in observable pits. With the increase of chloride concentration, the occurring potential for metastable pits Em rised, and peak values …

Study On Degradation Of Phenol By Electrochemical Oxidation, Yue-Li Liu, Hong-Hua Ge

Journal of Electrochemistry

Electrochemical oxidation of phenol was carried out by the Dimensionally Stable Anodes (DSA) electrode, which has been discarded as waste by alkali chloride factory. The result indicates that a good phenol removal can be obtained under certain phenol concentration by the DSA electrode. The key factor in effecting phenol removal of electrochemical oxidation is applied current density, the following factors are pH, electrolyte concentration and phenol concentration. After experiments, the optimal test conditions are 30 mA/cm², pH 10, electrolyte concentration 10 mg/L, phenol concentration 10 mg/L.67% CODcr removal and 90% absorbance removal are gained by electrochemical oxidation for …

Optimizing Catalyst Layer Composition Of Pemfc By Orthogonal Method, Ming-Hua Wang, Xin-Jian Zhu, Guang-Yi Cao, Sheng Sui, Qing-Chun Yu, Ming-Ruo Hu, Zheng-Yu Fan

Journal of Electrochemistry

The optimal composition of catalyst layer in a PEMFC electrode was studied through orthogonal method. It was showed that the performance of hydrophilic electrodes, in which there is no PTFE in the catalyst layer, were more favorable than that of hydrophobic electrodes. According to this condition, the power density of PEMFC attained 0.37 w·cm^-2 when the Nafion loading was 1.4 mg·cm^-2, and the Pt loading was 0.4 mg·cm^-2 in the catalyst layer, using H₂ as fuel and air as oxidant both at atmospheric pressure. Additionally, the results showed that increasing Pt loading in Pt/C catalyst …

The Study On Carbon Nanotube-Loaded Pt Catalysts For Proton Exchange Membrane Fuel Cells, Hong Zhu, Feng-Juan Ge, Xiao-Hong Kang, Yu-Guo Yang, Yun-Hua Xu

Journal of Electrochemistry

Carbon nanotube-supported-platinum (Pt/CNTs) and carbon-supported-platinum (Pt/C) catalysts were synthesized by in-situ chemical reduction. They were analyzed using TEM and XRD, then made into electrodes to be part of assemable PEMFC for the performence tests. The resulted show that Pt clusters in both catalysts are of small particle size (about 4nm), and Pt/CNTs exhibits a higher catalytic activity than Pt/C.

Adsorption And Oxidation Of Phenol Electrode Processes, Bao-Cheng Wang, Yan-Ping Sun, Jin-Hua Zhu

Journal of Electrochemistry

The electrochemical behaviors of platinum electrode were studied by cyclic voltammetry in 1mol/L sulfuric acid solution and 1mol/L sulfuric acid solution contained phenol. The adsorption characteristics of phenol and the intermediat on electrode surface have been discussed. The reactive reversibility and oxidation mechanism of phenol on electrode process have been investigated.The potential of characteristic adsorption was suggested. The various products woud be formed when the electrode potential was greater than the one of characteristic adsorption.

Modeling, Fabrication, And Optimization Of Niobium Cavities: Phase Iii Quarterly Report, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Niobium cavities are important parts of the integrated NC/SC high-power linacs. Over the years, researchers in several countries have tested various cavity shapes. They concluded that elliptically shaped cells are the most appropriate shape for superconducting cavities. The need for very clean surfaces lead to the use of a buffered chemical polishing produce for surface cleaning to get good performance of the cavities. The third phase concludes the experimental a fluid flow study and optimization study. The first quarter and second quarter of phase three also begins the experimental set-up of secondary emission studies from niobium in superconducting mode. This …

Synthesis And Electrochemical Properties Of K2Feo4, Ning Zhou, Shi-Hai Ye, Yong-Long Wang, Xue-Ping Gao, Dong-Feng Lin, Zuo-Xiang Zhou, De-Ying Song

Journal of Electrochemistry

The K₂FeO₄ used for new positive electrode materials was prepared. The primary batteries were used in different concentration of electrolyte and different currents. In 9 mol/L KOH , the capacity was the best. The higher the concentration of electrolyte, the lower the electric potential was. When the batteries discharged in 0.4 C , the capacity reached 521.3 mAh/g. By XRD, we gave the reasonable explanations for the discharge products of K₂FeO₄. Possible mechanism of discharge is discussed.