Chemical Engineering Commons^™

Discrete Element Modelling Of The Abrasive Dehulling Process Of Sorghum And Millet, E. L. Lazaro

Tanzania Journal of Engineering and Technology (TJET)

The abrasive dehulling process of sorghum and millet was modelled using a three-dimensional discrete element model. The model was validated by comparison between experimental and simulation results. Good correlation between experimental and simulation results was obtained. Several numerical experiments were also carried out using the developed model to investigate the influence of mill and grain parameters on dehulling of sorghum and millet. The simulated results correlated well with experimental results from literature. The developed model therefore provides a simple and cheap tool, which can be used to study the dehulling process in more detail than, is currently possible using the …

Properties Of Rice Husk Particle Boards Bonded By A Blend Of Tannin-Cnsl Resin, J. V. Tesha

Tanzania Journal of Engineering and Technology (TJET)

There are vast quantities of agricultural residues available in Tanzania. Rice husk being amongst those residues is reported to have low resistance to alkalis, high silica content, and have short fibres. These factors have made rice husks not attractive raw materials in panels’ production. However, it has been demonstrated that rice husks can be used to develop panel products of low cost and good performance if appropriate indigenous technologies and affordable binders that can bind siliceous materials are used.

This paper provides a summary on the study of the effectiveness of the binding characteristics of a blend of natural adhesive …

Computer Simulations And Neutron Reflectivity Of Proteins At Interfaces, Amol A. Mungikar, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Computer simulations in conjunction with neutron reflectivity is an excellent combination for the study of biological materials at solid-liquid interfaces: Both techniques have excellent resolution levels (Ångströms) and they are mature. A stronger interaction between physicists and biologists will allow the use of these two approaches in topics of biological-biomedical interest.

Novel General Expressions That Describe The Behavior Of The Height Equivalent Of A Theoretical Plate In Chromatographic Systems Involving Electrically-Driven And Pressure-Driven Flows, B. A. Grimes, S. Lüdtke, K. K. Unger, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Novel general expressions are constructed and presented that describe the behavior of the height equivalent of a theoretical plate (plate height), H, as a function of the linear velocity, Vx, along the axis, x, of the column and the kinetic parameters that characterize the mass transfer and adsorption mechanisms in chromatographic columns. Open tube capillaries as well as columns packed with either non-porous or porous particles are studied. The porous particles could have unimodal or bimodal pore-size distributions and intraparticle convective fluid flow and pore diffusion are considered. The expressions for the plate height, H, presented in this work could …

Iodat Analysis Content In Cooking Ingredients Using Iodometry And X-Ray Fluorescence Methods., Nelson Saksono

Makara Journal of Technology

Iodat Analysis Content in Cooking Ingredients Using Iodometry and X-ray Fluorescence Methods. Salt iodization program using iodine fortification into salt method is the best method that is effective and economical to overcome the problems caused by iodine deficiency. However in, its development there are some issues clamed that the use of iodized salt is ineffective since iodine content reduces, even disappear when the salt mix with other cooking ingredients. In order to investigated the existence of iodine in cooking ingredients, a research applying iodometry and X-ray fluorescence methods was carry out. The result obtained by iodometry method showed decreases in …

Emission Gas Reducer On Motor Vehicle, Automobile, Light Engine Of Boat And Stationary Combustion Engine., I Gusti Bagus Wijaya Kusuma

Makara Journal of Technology

Emission gas reducer on motor vehicle, automobile, light engine of boat and stationary combustion engine. The use of motor vehicle should be followed by protection against damages on the environment, since the exhaust gas from combustion engine has significantly affect on air and environmental pollution. One method to solve the problems in air pollution has been done by using a re-heater designed in Mechanical Engineering Department, University of Udayana. In accordance to the test on the re-heater, it can be seen very clear that the re-heater has significantly reduce the CO emission of about 54%. It also reduces the CO2 …

Application Of Remote Sensing For Mapping Soil Organic Matter Content, Bangun Muljo Sukojo, Wahono Wahono

Makara Journal of Technology

Application of Remote Sensing for Mapping Soil Organic Matter Content. Information organic content is important in monitoring and managing the environment as well as doing agricultural production activities. This research tried to map soil organic content in Malang using remote sensing technology. The research uses 6 bands of data captured by Landsat TM (Thematic Mapper) satellite (band 1, 2, 3, 4, 5, 7). The research focuses on pixels having Normalized Difference Soil Index (NDSI) more than 0.3. Ground-truth data were collected by analysing organic content of soil samples using Black-Walkey method. The result of analysis shows that digital number of …

Optimation Model Of Planning Investment Dockyard With Approach Multi Objective Goal Programming, Ali Azhar

Makara Journal of Technology

Optimation model of planning investment dockyard with approach multi objective goal programming. The purpose of this research is to determine decision variable, goal function, alternative priority and achievement function in investment planning. From this optimation component, the model of ship yard investment planning could be achieved. The model of developed model in this research was the optimation of ship yard investment planning using multi objective goal programming approach. The model consist of 5 decision variable, 11 goal function, 2 alternative priority and 11 achievement functions. The model implementation was done toward PT ASSI investment planning. The calculation using from Quantitative …

Self-Ignition Properties Of Peat, Palm Shell Fibre And Woods, Yulianto Sulistyo Nugroho

Makara Journal of Technology

Self-ignition properties of peat, palm shell fibre and woods. Forest fire is one of the greatest environmental problems faced by Indonesia. Forest fires have destroyed million hectares of forest and land which cause economic loss, social problems including smoke related diseases and environmental disaster with long time consequences. The exothermic reactions of forest fuels that lead to fire can be initiated by a piloted flame and low-temperature oxidation mechanism. This paper presents the results of low temperature oxidation studies using forests fuel samples i.e. palm shell fibre, peat, woods and low-rank coal. The measured values of the critical oven temperatures …

The Use Of 2d Plastic Grating For Surface Profile And Dimension Manufacture Product Measurements By Using Ndt Moiré Technique, Retno Wigajatri P., Dini Andiani

Makara Journal of Technology

The Use of 2D Plastic Grating for Surface Profile and Dimension Manufacture Product Measurements by Using NDT Moiré Technique. Research of measuring the shape and dimension of object using the moiré technique have been done. Measurement have been made by observing the moiré space as a result of interaction between grating and its shadow casted on the object’s surface caused by the projector lamp with CCD camera. The acquired data was further processed by way of off-line. By successive phase shifts that is π/2, π dan 3π/2 towards the table tennis ball at the distance of 48 cm from the …

Poly(Meta-Phenylene Isophthalamide) Nanofibers: Coating And Post Processing, Wenxia Liu, Mathew Graham, Edward A. Evans, Darrell Hyson Reneker

College of Polymer Science and Polymer Engineering

Electrospun nanofibers have applications in the areas of filtration, composites; biomaterials, and electronics. Controlling the surface properties of these nanofibers is important for many applications. Nanofibers can also be used as unique substrates for observing the growth of deposited films and creating nanoscale structures. In this work, electrospun poly(meta-phenylene isophthalamide) (MPD-I) nanofibers were used as substrates for creating nanoscale structures out of carbon-based materials and metals. MPD-I was used because it can be electrospun into nanofibers with diameters smaller than 10 nm and it has good thermal stability. MPD-I nanofibers were coated with carbon, copper, and aluminum using plasma enhanced …

The Effect Of Convection On Disorder In Primary Cellular And Dendritic Arrays, R. Trivedi, P. Mazumder, Surendra N. Tewari

Chemical & Biomedical Engineering Faculty Publications

Directional solidification studies have been carried out to characterize the spatial disorder in the arrays of cells and dendrites. Different factors that cause array disorder are investigated experimentally and analyzed numerically. In addition to the disorder resulting from the fundamental selection of a range of primary spacings under given experimental conditions, a significant variation in primary spacings is shown to occur in bulk samples due to convection effects, especially at low growth velocities. The effect of convection on array disorder is examined through directional solidification studies in two different alloy systems, Pb-Sn and Al-Cu. A detailed analysis of the spacing …

The Evolution And Implications Of The Concentration Profiles Of An Analyte In Porous Adsorbent Particles Packed In A Capillary Electrochromatography Column Operated In The Analytical Mode, B. A. Grimes, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this work, a mathematical model is constructed and solved to describe the propagation and dispersion of the mass wave of an analyte in a capillary electrochromatography (CEC) column packed with porous adsorbent particles and operated in the analytical mode. The evolution and dynamic behavior of the isoconcentration contours of the concentration of the analyte in the pores of the particles are presented in order to demonstrate the significant impact that the velocity of the intraparticle electroosmotic flow (EOF) encountered in CEC systems could have in reducing the overall intraparticle mass transfer resistance. It is shown that under both unretained …

Mechanistic Study Of Oxidation Of Hypophosphite On Pt Electrodes By Sniftirs, Tai-Xiang Jiang, Hui-Huang Wu

Journal of Electrochemistry

The oxidation of hypophosphite on a polycrystalline platinum electrode was studied by SNIFTIRS and cyclic voltammetry, the in-situ IR spectra were analyzed as a function of Pt electrode potentials in the solution of 0.5 mol/L H₂SO₄+0.1 mol/L NaH₂PO₂. It was found that the dissociative adsorption of hypophosphite ions occurs on Pt surface, and the oxidation product is H₃PO₄, rather than H₂PO₃^- which was considered to produce on Ni electrodes, thereby a new insight into mechanism of hypophosphite oxidation on Pt in acidic media was …

Nano-Sized Cobalt-Based Oxides As Negative Electrode For Lithium-Ion Batteries, Feng Huang, Zheng-Yong Yuan, Yun-Hong Zhou, Ju-Tang Sun

Journal of Electrochemistry

Nanosized cobalt-based oxide (Co₃O₄, CoB_1.36O_2.8 and CoB_0.5Al_0.1O_1.5) samples were prepared by rheological phase method and were tested as anodes in secondary lithium batteries. The cells were cycled between 0.01V and 3.00 V. The best electrochemical performance was obtained from the Co₃O₄ cell, which retained 95% of its initial capacity (931 mAh/g) after 30 cycles. The doping of B, Al reduced the reversible capacity during the first discharge/charge cycle, and the quantity of reversible capacity reduced with B, Al increasing. The modifying structures at difference …

Steady State Simulation Of Ysz Intermediate-Temperature Fuel Cell, Zi-Jing Lin, Ye Gu, Xiao-Hua Zhang

Journal of Electrochemistry

With a coupled 2D electrochemical and thermal modeling software, the characteristics of the steady state operation of the intermediate-temperature fuel cell with thin yttria-stabilized zirconia(YSZ) electrolyte was analyzed. The parameters of I-V equation were obtained from fitting the experiment results and the choice of grid points was determined by balancing the accuracy requirement and computational efficiency. The temperature fields at different operation circumstances such as flow designs, material choices for interconnect, were examined. The dependences of the output power and cell efficiency on the operating voltage at different temperatures were studied. Based upon the analysis of the temperature profile, it …

Preparation And Performance Of Lifeo2 Coated Nickel Oxide Cathode For Molten Carbonate Fuel Cells, Chun-Ming Wang, Fei Li, Ke-Ao Hu

Journal of Electrochemistry

A novel cathode for molten carbonate fuel cells was prepared by coating LiFeO₂ over the surface of porous NiO cathode by a simple combustion process. The analytical results of X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDAX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the LiFeO₂ coating on the surface of NiO particles consisted of nonometer-sized LiFeO₂ grains and sintered tightly with the NiO particles. The LiFeO₂ coating dramatically reduced the contacting area of NiO with the carbonate melts, thus the solubility of NiO in the carbonate melts was decreased. Meanwhile, …

Review Of Mathematical Model For Proton Exchange Membrane Fuel Cell, Shan-Hai Ge, Bao-Lian Yi, Hua-Min Zhang

Journal of Electrochemistry

In the review with 49 references, the mathematical models for proton exchange membrane fuel cell (PEMFC) were summarized. The mechanistic model and empirical model were introduced. Transfer in the membrane, catalyst layer, diffusion layer and flow field of PEMFC were described. The importance of water and heat management was analyzed. The dimension, complexity and solving methods of the PEMFC model were discussed. The importance and validity to develop a model with time dimension are put forward.

Electrocatalytic Oxidation Of Formic Acid On Molybdate-Modified Platinum Electrode, Jun-Hua Du, Xue-Hui Xu, Hong Li, Hong-Yu Cheng, Wei-Shan Li

Journal of Electrochemistry

The electrochemical behavior of molybdates on a platinum electrode in H₂SO₄ solutions with different H₂SO₄ concentrations was studied by cyclic voltammetry and double chronoamperometry. Molybdates were reduced to adsorb hydrogen molybdenum bronzes on the platinum electrode in H₂SO₄ solutions during cathodically potential sweep. The hydrogen molybdenum bronzes were oxidized to different forms of hydrogen molybdenum bronzes with less hydrogen, depending on the H₂SO₄ concentration. Platinum electrode was modified by these hydrogen molybdenum bronzes. However, this modified electrode was not stable in H₂SO₄ solutions. The modified …

Manufacture Of 1 Kw Molten Carbonate Fuel Cell Stack, Sheng Sui, Xin-Jian Zhu, Zheng-Yu Fan, Guang-Yi Cao

Journal of Electrochemistry

A molten carbonate fuel cell stack with an active area of 240 mm×140 mm consisted of 30 cells. The gas feed system works via interior manifolds, and the stack placed in a couple of self-chest, coupled with a heater at the bottom and other fours surrounded,to keep uniformity of temperature.Under ambient pressure and 650 ℃, fed with hydrogen and air as anode and cathode gases respectively, the stack gave a current density of 150 mA/cm² at an average cell voltage of 0.7 V. The peak output of the stack was 1.06 kW during its performance of 300 h.

Method, Apparatus And Article For Microfluidic Control Via Electrowetting, For Chemical, Biochemical And Biological Assays And The Like, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

An active-matrix microfluidic platform employs thin film transistor active ("TFT") matrix liquid crystal display ~ technology to manipulate small samples of fluid for chemical, biochemical, or biological assays without moving parts, for example, using a two-dimensional matrix array of drive electrodes. The active-matrix microfluidic platform may employ existing active matrix 0 addressing schemes and/or commercial "off-the-shelf" animation software to program assay protocols. A feedback subsystem may > determine an actual location of a fluid in the microfluidic structure, and provides location information to for display, for example, on an active-matrix display, and/or to control movement of one or more fluid bodies …

An Approach To Sequence Dna Without Tagging, Sanjun Niu, Ravi F. Saraf

Papers in Biotechnology

Microarray technology is playing an increasingly important role in biology and medicine and its application to genomics for gene expression analysis has already reached the market with a variety of commercially available instruments. In these combinatorial analysis methods, known probe single-strand DNA (ssDNA) ‘primers’ are attached in clusters of typically 100 μm × 100 μm pixels. Each pixel of the array has a slightly different sequence. On exposure to ‘unknown’ target ssDNA, the pixels with the right complementary probe ssDNA sequence convert to double-stranded DNA (dsDNA) by a hybridization reaction. To transduct the conversion of the pixel to dsDNA, the …

Accurate Quantification Of Steady And Pulsatile Flow With Segmented K-Space Magnetic Resonance Velocimetry, Haosen Zhang, Sandra S. Halliburton, James R. Moore, Orlando P. Simonetti, Paulo R. Schvartzman, Richard D. White, George P. Chatzimavroudis

Chemical & Biomedical Engineering Faculty Publications

Conventional non-segmented magnetic resonance phase velocity mapping (MRPVM) is an accurate but relatively slow velocimetric technique. Therefore, the aim of this study was to evaluate the accuracy of the much faster segmented k-space MRPVM in quantifying flow. The axial velocity was measured in four straight tubes (inner diameter: 5.6–26.2 mm), using a segmented MRPVM sequence with seven lines of k-space per segment. The flow rate and flow volume were accurately quantified (errorssteady (r²=0.99) and pulsatile flow (r²=0.98), respectively. The measured velocity profiles and flow rates from the segmented sequence agreed …

Microbial Cellulose Utilization: Fundamentals And Biotechnology, Lee R. Lynd, Paul J. Weimer, Willem H. Van Zyl, Isak S. Pretorius

Dartmouth Scholarship

Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial …

Synthesis And Enzymatic Resolution Of Amino Acid Esters In "Green" Solvents -- Ionic Liquids, Hua Zhao

Dissertations

Chiral separation has attracted tremendous attention in pharmaceutical and chemical fields, especially in the area of chiral drug development. Chiral amino acids are among the most important intermediates in the asymmetric synthesis of modem drugs. This research has developed an effective method for obtaining optically pure amino acids by enzymatic resolution using a "green" solvent, named an ionic liquid.

Ionic liquids, a new type of "green" solvents, have been used in many organic reactions and other chemical processes (such as liquid-liquid extraction) with improved performance. This is mainly due to their favorable properties for chemical applications, such as low vapor …

Ionic Conduction In Ba0.95Ce0.9Y0.1O3 - Α Solid Oxide And Its Performance In Fuel Cell, Gui-Lin Ma, Ding-Xian Jia, Li-Gan Qiu, Hui Shi, Rong Chen

Journal of Electrochemistry

Using Ba_0.95Ce_0.9Y_0.1O_3-α as a solid electrolyte and porous platinum as electrodes,hydrogen and oxygen concentration cells and hydrogen-air fuel cell were constructed, respectively. Electromotive forces (MEFs) of the gas concentration cells and I-V characteristics of the fuel cell were detdrmined in the temperature range of 600～1 000 ℃. The Ba_0.95Ce_0.9Y_0.1O_3-α exhibited almost the pure protonic conduction under hydrogen gas,and a mixed conduction of oxide-ion and electron hole with oxide-ion transport number of 0.3～0.5 under oxygen gas. It exhibited a mixed conduction of proton and oxide-ion with the …

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, …

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.

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 …

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 …