bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Humic Acid on Geochemistry Properties of Kaolin
Authors: Pakir Faizal Bin , Abdul Karim Ahmad Tarmizi Bin , Ling Felix N.L. , Kassim Khairul Anuar
Published: May 2013

Organic soil is always known as problematic soil because of its engineering properties are inferior from other soft soils and/or because its behaviour may deviate from traditional rules of soil behaviour which makes it difficult to predict and design. Considerable research has been carried out over the years on organic soils, particularly peat soil which consists of various components of organic matter but the effect of particular organic matter is less reported. Hence, this study is carried out to determine the effect of humic acid (a kind of humified organic matter) on kaolin (which is widely studied). This paper addresses the influence of humic acid (30% and 50% of dry mass) on kaolins geochemistry properties namely Atterberg limits, compaction, specific gravity and Loss on Ignition (LOI). The findings of the study showed that the contents of humic acid had altered the behaviour of kaolin. The loss on ignition increased linearly with the increment of humic acid. However, the specific gravity, maximum dry density and Atterberg limits decreased with addition of humic acid. Atterberg limits decreased as the humic acid increased is believed to be due to the nature of humic acid which precipitated under acidic environment.
Comparative Electrochemical Performance Characteristics of Aluminium-Air Cell Employing Seawater and NaCl Electrolytes
Authors: Akmal Maziati , Othman Raihan , Ani Mohd Hanafi
Published: May 2013

The electrochemical performance of Al-air cell employing seawater and NaCl electrolyte of various concentrations has been investigated. The open circuit voltage and discharge capacity of the cell correlate well with the electrolyte conductivity data. Using 4 M NaCl electrolyte which possesses the highest conductivity, the Al-air cell registers an open circuit potential (OCV) of 1.1 V and demonstrates discharge capacity of 250 mAh, rated at 1 mA. Upon employing seawater, the OCV reduced to 0.68 V and discharge capacity decreased to 150 mAh. However, utilizing an exposed cell configuration which mitigates the hydroxide gel water binding effect, the Al-air seawater cell performance is greatly enhanced until almost compatible to Al-air cell employing 4 M NaCl.
The Effect of Amorphous Rice Husk Silica to the Polysulfone Membrane Separation Process
Authors: Harun Zawati , Jamalludin Mohd Riduan , Yunos Muhamad Zaini , Shohur Muhamad Fikri , Ismail Ahmad Fauzi
Published: May 2013

This study investigates the effect of additive rice husk silica and Polyethylene glycol (PEG) on the performance of polysulfone (PSf) membrane. The membrane was prepared by phase inversion method using PSf, N-methyl-2-pyrrolidone (NMP) and rice husk silica was added as an additive. The performance of the membrane was analyzed by using distilled water for permeation test and humic acid for the rejection test. The result showed that the hydrophilic of PSf/PEG membrane has significantly improved the permeation and rejection performance with addition of rice husk silica. The results showed that with addition of 3% rice husk silica give the highest rejection flux at 196.63 L/m2hr with the rejection value 98%.
Flexural Strength Behavior of Composite UHPFC - Existing Concrete
Authors: Tayeh Bassam A. , Bakar Badorul Hisham Abu , Megat Johari Megat Azmi , Zeyad A.M.
Published: May 2013

Ultra high performance fiber concrete (UHPFC) is an advanced formula concrete that is proven to be more superior than conventional concrete because it embrace the qualities of steel and concrete. Therefore UHPFC properties which include high durability and strength are fully exploited in the research of rehabilitation and strengthening in concrete and even non-concrete structures. This article presents the findings of an experimental study carried out to examine the bonding strength behaviour between normal concrete (NC) substrate and UHPFC as a repair material, under flexural strength test by using third-point loading beam test method. Three types of NC substrate surface preparation were used: as-cast (without surface preparation) as a reference, wire-brushed, and sand-blasted. The flexural test results clearly indicated that all failures occurred through the NC substrate and no de-bonding was observed in the interface between NC substrate and UHPFC. The results of the flexural strength confirmed that adhesion bond strength between NC substrate and UHPFC was stronger than the substrate regardless, the substrate roughness. This proves that UHPFC is able to link and bond strongly with the substrate.
Natural Corrosion Inhibitor for Corrosion Protection of Metal Artefact: An Overview
Authors: Musa Mukhtaruddin , Ani Mohd Hanafi , Othman Raihan
Published: May 2013

The degradation of most of metals, with the exception of gold is a universal reaction. It is a constant and on-going problems, make it often difficult to eliminate completely causing either industrial or heritage conservation losing a lot of money. One way and most practical for corrosion protection are using green inhibitor. Therefore it is widely use either industry or heritage conservation. Unfortunately, the inhibitors used in conservation are frequently hazardous to conservator, either through inhaler or touch with skin. Responding to this, several researches has been conducted to look into environmental friendly inhibitors or green inhibitors. This paper will review current practice use of inhibitor in metal preservation before propose a new inhibitor which been used a long time ago in Malay traditional practice in Keris preservation.
Mathematical Modelling of Urea-Formaldehyde Polymerization Kinetics Using Mechanism Approach
Authors: Ruamcharoen Polphat , Ruamcharoen Jareerat
Published: May 2013

Nowadays, formaldehyde is considered to be a hazardous volatile chemical. One of the formaldehyde sources is urea-formaldehyde resin which is mainly used as an adhesive in particleboard production. Hence, it is necessary to minimize the formaldehyde residue from urea-formaldehyde synthesis. This present work involves the kinetic modelling of urea-formaldehyde polymerization to predict formaldehyde concentration during the pre-polymerization process. On the basis of previous proposed mechanism, the kinetic model which accounted for the number of the functional groups on urea and formaldehyde and also reactive polymer chains was developed as a set of ordinary differential equations (ODEs). The formaldehyde concentrations from computer simulation results were compared with those from experimental investigation. Good agreement between simulation and experimental results was obtained. The developed kinetic model can be also applied to predict the functional group evolution during polymerization. This helps producers select the condition for production to minimize formaldehyde residue and predict the chemical structure of final product.
Simplified Colorimetric Method Using Reactive Orange 16 for Analysis of Cationic Surfactant
Authors: Puasa S.W. , Ruzitah M.S. , Sharifah A.S.A.K.
Published: May 2013

The concentration of surfactant is usually determined by a colorimetric method. A simplified colorimetric method for determining cationic surfactant was proposed which has advantages over the existing colorimetric method where less chemical is used and the overall time to perform the analysis per sample is reduced by half. These methods were tested based on analyzing the ionic interaction of cationic surfactant-reactive orange 16 (PBE-RO16) mixtures. A linear correlation was observed between the absorbance ratio of PBE-RO16 mixture/dye and PBE concentration. Results obtained from this study shows that the error between the two methods is only about ±20% except for PBE concentration less than 20 mg/L. Therefore, the proposed simplified colorimetric method can be considered as an alternative method for determination of cationic surfactant in aqueous solution in the future.
Influence of Machining Parameters on Surface Roughness in WEDM Titanium Alloy
Authors: Saedon J.B. , Ding J.R. Paul J.R. , Shawal M.S.M. , Husain H. , Meon M.S.
Published: May 2013

Wire electrical discharge machining (WEDM) is a material removal process of electrically conductive materials by the thermo-electric source of energy .This kind of machining extensively used in machining of materials with highly precision productivity. This work presents the machining of titanium alloy (TI-6AL-4V) using wire electro-discharge machining with brass wire diameter 0.25mm.The objective of this work is to study the influence of three machining parameters namely peak current (IP), feed rate (FC) and wire tension (WT) to material removal rate and surface roughness followed by suggesting the best operating parameters towards good surface finish. A full factorial experimental design was used with variation of peak current, feed rate and wire tension, with results evaluated using analysis of variance (ANOVA) techniques. Parameter levels were chosen based on best practice and results from preliminary testing. Main effects plots and percentage contribution ratios (PCR) are included for the main factors and their interactions. Peak current was shown to have the greatest effect on surface roughness (33% PCR).
Investigation of Chip-Tool Interface Temperature during Turning of Hardened AISI 4340 Alloy Steel Using Multi-Layer Coated Carbide Inserts
Authors: Chinchanikar Satish , Choudhury S. K. , Kulkarni A. P.
Published: May 2013

In the present work, effect of work material hardness and cutting parameters on chip-tool interface temperature was investigated during turning of AISI 4340 steel hardened at two different levels of hardness 35 and 45 HRC, respectively, using CVD applied multi-layer TiCN/Al2O3/TiN coated carbide inserts. A tool-work thermocouple principle was used to measure the interface temperature during turning. The correlation coefficient between experimental and predicted values of interface temperature found close to 0.95, which showed that the developed model is reliable and could be used effectively for predicting the interface temperature for the given tool and work material pair and within the domain of the cutting parameters. Experimental observations indicate that the interface temperature is higher for harder work material and get affected mostly by cutting speed followed by feed. However, depth of cut has little influence on interface temperature irrespective of the hardness of the workpiece.
Real Coded Genetic Algorithms for Solving Flexible Job-Shop Scheduling Problem - Part I: Modelling
Authors: Mahmudy Wayan Firdaus , Marian Romeo M. , Luong Lee H.S.
Published: May 2013

This paper and its companion (Part 2) deal with modelling and optimization of the flexible job-shop problem (FJSP). The FJSP is a generalised form of the classical job-shop problem (JSP) which allows an operation to be processed on several alternatives machines. To solve this NP-hard combinatorial problem, this paper proposes a customised Genetic Algorithm (GA) which uses an array of real numbers as chromosome representation so the proposed GA is called a real-coded GA (RCGA). The novel chromosome representation is designed to produces only feasible solutions which can be used to effectively explore the feasible search space. This first part of the papers focuses on the modelling of the problems and discusses how the novel chromosome representation can be decoded into a feasible solution. The second part will discuss genetic operators and the effectiveness of the RCGA to solve various test bed problems from literature.
Real Coded Genetic Algorithms for Solving Flexible Job-Shop Scheduling Problem - Part II: Optimization
Authors: Mahmudy Wayan F. , Marian Romeo M. , Luong Lee H.S.
Published: May 2013

This paper addresses optimization of the flexible job-shop problem (FJSP) by using real-coded genetic algorithms (RCGA) that use an array of real numbers as chromosome representation. The first part of the papers has detailed the modelling of the problems and showed how the novel chromosome representation can be decoded into solution. This second part discusses the effectiveness of each genetic operator and how to determine proper values of the RCGAs parameters. These parameters are used by the RCGA to solve several test bed problems. The experimental results show that by using only simple genetic operators and random initial population, the proposed RCGA can produce promising results comparable to those achieved by other best-known approaches in the literatures. These results demonstrate the robustness of the RCGA.
Overview Potential Applications of Cold Spray Process for Aviation Industry in Malaysia
Authors: Nooririnah O. , Khalil A.Y. , Aludin M.S. , Rohana A. , Zuraidah R.R.
Published: May 2013

Malaysia plans to become a regional hub for aircraft maintenance and repairs. The country was currently ranked fifth in Asia and tenth in the world in terms of aircraft maintenance, repair and overhaul.It show a positive sign for aviation industry in Malaysia.Maintenance or repair technique play a major role in increasing useful life of the aerospace part and it increase the confident level of the user. This paper is an outcome to discuss Cold spray process as potential repair technique which is widely acclaimed for its ability to perfom a bonding with the underlying material without the creation of heat affected zones which are typical of other deposition processes (thermal spray) and are undesirable in many structural applications. One of potential application for Cold spray process is dimensional restoration or tooling repair like chipped area, if the defect exceed repairable limit that provided by OEM, that part considered scrap. Cold spray can provided environmental friendly solution to thick deposit for dimensional restoration or tooling repair without creation heat affected zone.There is no application yet of this repair technology in Malaysia and on top of that,re-use of material will contribute to cost saving and in-haze the environmet.
Development of a New Approach for Incorporating Tool Tilting in Friction Stir Welding
Authors: Ghazanfar Bilal , Awang Mokhtar , Khan Sajjad Raza , Fawad Hasan
Published: May 2013

Friction Stir Welding (FSW) is a simple process involving a rotating tool (with an extended pin) traversing on the joining line of the two work pieces leaving behind the required weld. Tool geometry (pin and shoulder), rotational speed, traverse speed, and tilt angle are important parameters which determine the resultant properties of weld. Milling machines due to rotating tool and traversing can be used as a method of doing laboratory scale FSW experiment. In cases where milling machines have a fixed head, limitation of zero degree tool tilt angle results in substantial defects (e.g. tunnel defect) in weldments. In this study a new approach is developed and adopted for overcoming this limitation of a fixed head vertical milling machine to incorporate the flexibility of tool tilt. The results for welding with and without this approach are presented along with discussion and conclusion.
Screening Microbial Surface Active Compound Produced by Bacteria Isolated from Various Waste Streams
Authors: Marajan Caroline , Ramasamy Kalavathy , Abdul Talib Suhaimi
Published: May 2013

Microbial surface active compounds (SACs) have been studied for bioremediation of non-aqueous phase liquids (NAPLs) contaminated sites where SACs reduce the surface tension and therefore improve the bioavailability of NAPLs. Hence, this study evaluates presence of microbial SACs in culture medium by detecting the surface activity of potential SAC-producing bacteria. Twenty-five strains isolated from various waste streams in Malaysia were screened for SAC production by preliminary screening tests, namely using drop collapse, oil spreading and microplate tests. Strains were further checked using complementary screening by measuring the surface tension. Four strains (P-UT4, P-UT5, P-UT6 and P-UT8) isolated from untreated palm oil mill effluent (POME) exhibited high surface active properties when tested through preliminary screening tests. These strains were also capable of reducing surface tension of water (72 mNm-1) to below 40 mNm-1 and thus were identified as potential SAC-producing bacteria.
Characterization of Rambutan Seed (Nephelium lappaceum) as Natural Adsorbent for Wastewater Treatment
Authors: Ibrahim Norlia Mohamad , Mohd Sarif Siti Fatimah Zahra , Che Amat Roshazita , Salehuddin Shamshinar , Rahim Nur Liza
Published: May 2013

Activated carbons were prepared from rambutan seed with impregnation of zinc chloride as dehydrating agent. In order to find its characteristics, different zinc chloride to rambutan seed ratio (0.5 and 2) and activation temperature (450 and 650 °C) was employed. The carbonization occurred in a tube furnace with flow of nitrogen gas at 0.5 L/min. The results showed that at higher impregnation ratio and carbonization temperature produced a wider BET surface area of activated carbon that was 9.8761 m2/g. Total pore volume also increased with increases of these two factors. However activation yield was decreased with increasing of carbonization temperature.
Comparison of Melt Flow and Mechanical Properties of Rice Husk and Kenaf Hybrid Composites
Authors: Noor Zuhaira Abd Aziz , Mohamed Rahmah
Published: May 2013

This research is to identify the difference in melt flow and mechanical properties in hybrid composites between kenaf and rice husk that each of the filler was compounded with composite material of calcium carbonate (CaCO3) and high density polyethylene (HDPE) in different loading amount. Different filler loading up to 30 parts of kenaf fibers and rice husk particulate were mixed with the fixed 30% amount of CaCO3. Compounded hybrid composite were prepared and tested for melt flow index, tensile and impact strength. Addition of both fillers had decreased melt flow index (MFI). MFI of rice husk/CaCO3 was higher than kenaf/CaCO3 in HDPE composites. Tensile strength, elongation at break and impact properties of both hybrid composites had decreased with increasing filler content. Tensile strength of kenaf/CaCO3 was higher than rice husk/CaCO3 due to intrinsic fiber structure of kenaf which has some reinforcing effect compared to rice husk. While, impact strength of rice husk/CaCO3 was improved with addition of filler but drastically decrease as the rice husk content were increased up to 30% due to high silica content in rice husk. The Youngs Modulus was increased with addition of natural fibers in CaCO3/HDPE composite.
Analysis of Surface Electromyography for On-Off Control
Authors: Chan B.S. , Sia C.L. , Wong Farrah , Chin Renee , Dargham Jamal A. , Siang Yang Soo
Published: May 2013

Myogram on-and-off controller is important for improving or assisting the elderly people. One of the most important aspects of the controller development is to determine the on and off time with respect to the body movement. In this project, high accuracy signal filtering, high gain amplifier, signal converter, microcontroller and electrodes are used for circuit simulation and development to obtain muscle signal (Electromyogram). Precision rectifier is used to solve the ordinary semiconductor problem to avoid signal block. To ensurethe user-friendliness in the development of this device, non-invasive electrodes are used in this project instead of invasive electrodes.
Dielectric Properties of the Composite Insulator Mica Epoxy-Novolac
Authors: Gavrilă Doina Elena , Gavrilă Horia Catalin
Published: May 2013

As electric insulators of the copper conductors in the electric generators of alternative current or in electric motors of high tension, there are used with priority the composite crosslinked mica-epoxy. Pre-impregnated band with solvent was introduced, the impregnation being performed with phenolic-novolac resin. The studied material got superior dielectric properties at function temperatures corresponding to the insulation class F(155C). Its main components are: mica paper (53%), glass cloth (13%) and the basic epoxy phenolic-novolac resin. The complex permittivity and conductivity were determined with the Time Domain Spectrometer (TDS); the apparatus allows the determination of the electric values in the domain of frequencies: very large domain of frequencies. The temperature varied in the domain 23-190C with the help of an oven. The purpose of this article is to report the dielectric properties of mica-epoxy-novolac composite insulator, for which very few data have so far been published.
Environmental Stress Cracking Resistance (ESCR) of Rubber-Toughened Polyester-Kenaf Composites under Active Environment
Authors: Shuhaimen N.S. , Bonnia N.N. , Aein Afina Mohd Redzuan , Mohamed M.R.H.
Published: May 2013

This study was undertaken to investigate mechanical and morphological properties of rubber toughened polyester composite filled with kenaf and was exposed in varying natural weathering and difference environmental condition (Artificial Sea Water (SW), Distilled Water (DS), Environment Exposure (EX) and Soil Exposure (SL)). Rubber-toughened polyester-kenaf fibre composites were prepared by adding 25% of kenaf fibre in unsaturated polyester resin and cross linked with a mixture of methyl ethylketone peroxide and cobalt octanoate. Three percent (3%) of liquid natural rubber (LNR) were added as a toughening agent. The sample was prepared using compression molding technique. It was found that the samples that being immersed in seawater (SW) had lower mechanical properties values as compare with other conditions. The value of flexural modulus and flexural strength were decrease by 35.9 % , 12.5% but the value of impact strength had slightly increase by 34% .The microstructures of the composites fracture surface were examined using a scanning electron microscope (SEM).
Evaluation on Diffusion of Bipolar Junction Transistor (BJT) Charge-Carrier and its Dependency on Total Dose Irradiation
Authors: Abdul Amir Haider F. , Chee Fuei Pien
Published: May 2013

Electronic device that subjected to various effects by radiations can cause small interferences such as noises in the circuit. These effects are especially critical in operating environment such as outer space, where radiation comes in stronger and more frequent. In this research, analytical study on the effects of ionizing radiation induced by 60Co gamma (γ) rays in bipolar junction transistor (BJT) devices had been performed. It was found that the high energy of the radiation allows more valence electrons to be excited to the conduction band in the BJT. This leads to the production of a large number of excited atoms and increases the holes in the valence band. The increase of holes in the base region due to trapping will increase the probability of recombination and reducing the number of electrons that reaches the collector region. This ionizing radiation effect was found to arouse either a permanent or temporarily damage in the devices depending on their current drives and total dose absorbed.
Fatigue Life for Type 316L Stainless Steel under Cyclic Loading
Authors: Mohammad Khairul Azhar , Zainudin Edi Syam , Sapuan S.M. , Zahari Nur Ismarrubie , Aidy Ali
Published: May 2013

The paper presents the determination of fatigue life of 316L stainless steel at room temperature. Plenty of steel in the world has been investigated for a lot of application in the science and technology market. The mechanisms of fatigue of 316L stainless steels were studied and investigated. Fatigue tests of specimens were performed in accordance with ASTM E466-96. The fatigue tests were performed in constant load amplitude, constant frequency of 5 Hz with load ratio R=0.1. Fracture surface of specimens were examined by using Scanning Electron Microscope (SEM). The results showed that the endurance fatigue limit of 316L stainless steel was 146.45 MPa.
Effect of Tubes Length and Annealing Temperature on Energy Absorption of Aluminium Alloy Tube 6061-T6 under Inversion Collapse Mode
Authors: Meon Mohd Suhairil , Othman Muhamad Fauzi , Mahamad Basri Mahamad Hisyam , Husain Hazran , Saedon Juri B.
Published: May 2013

The purposes of this study are to investigate the effect on variation of the specimens tube length and annealing temperature on the amount of energy absorption of Aluminium tubes (AA 6061) towards inversion collapse mode. The tests were performed on the Aluminium tubes using compression test according to ASTM E8 standard procedure. In this study, a quasi-static inversion tests were conducted in order to obtain the energy absorbed during inversion stages. It was found that the energy absorbed by Aluminium tubes were increased by increasing the tube length but decreased with annealing temperature.
Review of Self-Healing Effect on Shape Memory Alloy (SMA) Structures
Authors: Hassan M.R. , Mehrpouya M. , Emamian Sattar , Sheikholeslam M.N.
Published: May 2013

Self-healing has usually an emphasis on special materials that is metallic materials. When there is a minor damage, almost all biological organisms, even complex ones, have the ability to repair themselves. Recently, a novel field of materials science is constituted by self-healing in organic materials or material systems and it is rapidly expanding. These materials have a particular ability to heal themselves. The initial crack is healed to the point that upon reloading, a new crack is formed next to the original, rather than the original crack reopening. Only simple heating can reverse transformation and cause reinforcement for these cracks. The shape memory alloy wires are activated by heating the system and therefore the healing begins. Due to the heat, the wires relapse to their original shape at the shape change in martensite to austenite transition temperature. The concentration of most of the studies so far has been on polymers and ceramics and the reason is that it includes self-healing in non-metallic materials. Also, they are more convenient than including it in metallic materials. In this review paper the design principles of self-healing materials and their improvement methods are investigated.
Effect of Chitosan Compounds on Composite Fibers Properties
Authors: Suwannamek Natthaphop , Srikulkit Kawee
Published: May 2013

The primary aim of this paper is to provide an insight on the effect of chitosan compounds on the properties of polypropylene/chitosan composite fiber prepared by melt spun process. Three types of chitosan powder including ball mill prepared chitosan, spray dry prepared chitosan, and soybean oil-g-chitosan were employed for the preparation of chitosan compounds using polypropylene as polymer matrix. Then, chitosan compounds were incorporated into polypropylene fibers by melt spinning process. Polypropylene fibers containing chitosan particle loadings of 0.5 wt%, 1 wt%, and 3 wt% were prepared. Tensile strength, thermal property, morphology of chitosan compounds and fibers were investigated. The soybean oil-g-chitosan particles were found well distributed in PP matrix due to the compatibility of hydrophobic interfaces. However, spray dry-chitosan exhibited the best reinforcement effect by imparting the highest toughness compared to the others.
Cryogel Based Oil Encapsulation for Controlled Release of Curcumin by Using a Ternary System of Chitosan, Kappa-Carrageenan, and Carboxymethylcellulose Sodium Salt
Authors: Sowasod Nataporn , Nakagawa Kyuya , Tanthapanichakoon Wiwut , Charinpanitkul Tawatchai
Published: May 2013

Cryogel based oil encapsulation was attempted with a ternary system of colloidal chitosan, κ-carrageenan, and carboxymethylcellulose sodium salt (NaCMC). Favourable formulations of this ternary system that caused irreversible sol-gel transition by freezing (cryogelation) were found in this study, and the oil phase that contained a selected model food ingredient (curcumin) was successfully encapsulated in this prepared cryogel matrix. The encapsulation yields were found to vary from ca 89 to 99%, and the values were influenced by the cooling protocol used during freezing, thereby indicating that the gel formation kinetics was intimately related to the degree of encapsulation. The release behaviours of the ingredient were investigated in aqueous systems. The release curves showed that both a burst release and a first order release were achieved simply by changing the freezing condition. Freezing could modify the gel formation of the present cryogel, and the resulting structural modification evidently controlled the oil encapsulation manner. The prepared cryogels were found to be sensitive to the ambient pH. It was suggested that the ternary system of chitosan, κ-carrageenan, and NaCMC is an interesting matrix for designing controlled release system.
TiO2 and Metal-Doped TiO2 Performance for the 4-Chlorophenol Degradation in Batch and Continuous Reactors
Authors: Tangsatjatham Sitthichai , Rangsunvigit Pramoch , Chavadej Sumaeth
Published: May 2013

Photocatalytic degradation of 4-chlorophenol (4-CP) was investigated with a series of TiO2 and TiO2 doped with Ag and Au. Experiments were carried out in both batch and continuous reactors under an 11 W low pressure mercury lamp. Total organic carbon (TOC) was used as an indicator in addition to the concentration of 4-CP for the effectiveness of the degradation. In the batch reactor, a catalyst was suspended in aqueous 4-CP solution. Interestingly, 4-CP degradation did not depend on the catalyst used compared to photolysis. On the contrary, the presence of any of the catalyst significantly affected the intermediates, hydroquinone and hydroxyhydroquinone, degradation. Degussa P25 showed higher catalytic activity than the synthesized TiO2 and in some cases TiO2 doped with a precious metal in terms of TOC degradation. The addition of the precious metal to TiO2 did not improve the 4-CP degradation but it did on the degradation of the intermediate products. Degussa P25 was dip-coated on stainless steel mesh and used in the continuous reactor. With the continuous reactor, experimental conditions could be set so that complete degradation could be achieved.
Effects of Metal Loading and Milling Time on Hydrogen Storage on Modified Graphite
Authors: Jannatisin Visara , Suttisawat Yindee , Rangsunvigit Pramoch , Kitiyanan Boonyarach , Kulprathipanja Santi
Published: May 2013

This paper examines the effect of metal loading (Zr-, V-, Ti-, and K-compounds) on the hydrogen storage property of mechanically milled graphite. The hydrogen adsorption took place at room temperature and 11 MPa measured by thermal volumetric analysis. The results showed that the graphite loaded with ZrCl4provided a maximum hydrogen storage capacity of 0.6 wt%. Moreover, a milling time of 2 h seems to be the best, offering the highest hydrogen adsorption capacity due to the high specific surface area and the appropriate pore diameter created after the milling. In addition, it was found that the transition metals (ZrCl4and VCl3) could stabilize the graphite structure and enlarge the gap between the grapheme layers to be suitable trapping sites for hydrogen adsorption. On the other hand, the K2CO3and TiO2loaded graphite did not show any improvement for hydrogen adsorption.
Relibility Analysis of Hydrostructures Concrete Members
Authors: Wang Yan , Zhang Hong Wu , Gao Rui , Wang Xiang Dong , Yang Ling Qiang
Published: May 2013

The failure process of hydro structures concrete structure and time and space has stochastic relation. The durability failure mechanism, durability failure type and durability failure mode were presented in the paper which is different from caviling engineering. The relation of durability and resisting ability was studied. Based on credibility theory, service-life of hydro structure concrete member was predicted. and the mend measures to improve durability was put forward.
Novel Microwave Reduction Sintering for Perovskite Anode
Authors: Chang Horng Yi , Wang Yao Ming , Lin Chia Hsin , Cheng Syh Yuh
Published: May 2013

The La0.3Sr0.7Ti0.9Nb0.1O3 (LSTN) is a good anode material in solid oxide fuel cell (SOFC) due to its resistance to sulfur poison and carbon fiber deposition. The LSTN was studied by a novel microwave processing in activated carbon and flowing atmosphere of (5%H2+95%Ar). The pure perovskite structure is obtained for different microwave power and duration to indicate that the fast microwave reduction process could maintain stable perovskite structure. The conductivity of LSTN increases with the decrease of flow rate of 5%H2+95%Ar. More semiconducting characteristics but less metallic conductivities are achieved by microwave process. A stable microwave power 300W and a dwell time 12 min with an appropriate flow rate 40 cc/min can achieve the best conductivity of LSTN. The microwave reduction sintering obtains high conductivity of LSTN which is far higher than the one by conventional sintering at 1500°C-3 h.
Investigation of Curing Kinetics of Azo-Containing Twin Liquid Crystalline Epoxy Resins with Anhydride
Authors: Shen Teng Fei , Sun Chun Feng , Sun Ying Juan
Published: May 2013

A series of novel azo-containing twin liquid crystalline (LC) epoxy monomers were cured with anhydrides without extra catalyst and the curing kinetics was investigated by non-isothermal differential scanning calorimetry (DSC) technique. The results showed that the effect of phase behavior on activation energy (Ea) was very great. The chemical kinetic control and diffusion control mechanisms dominant the curing together, which gives a larger value of Ea. Azo group also served as a catalyst to accelerate the curing reaction.
Study on Curing Mechanism of Azo-Containing Twin Liquid Crystalline Epoxy Resins with Anhydride
Authors: Shen Teng Fei , Wu Fa Chao , Sun Ying Juan
Published: May 2013

A series of novel azo-containing twin liquid crystalline (LC) epoxy monomers were cured with anhydrides without extra catalyst and the curing kinetics was investigated by non-isothermal differential scanning calorimetry (DSC) technique. The effect of Azo group on the Curing Kinetics of Epoxy/anhydride System was investigated and the result showed that Azo group served as a catalyst to accelerate the curing reaction. The curing mechanism was confirmed by the UV-Vis spectrum.
Effect of In2S3 Buffer Layer in TiO2/In2S3/CuInS2 Structure
Authors: Tzeng Wei Jei , Wu Mei Lun , Lin Li Jiaun , Chang Horng Yi
Published: May 2013

The anodized TiO2nanotube arrays (TNAs) have a benefit to provide large surfaces and straight electron transmitting routes to the electrode. However, it is difficult to fulfill with solid state electrolytes or photosensitive materials into the long TiO2nanotubes. The substrate of Ti/wave-like TiO2was prepared by peel-off the TNAs. The In2S3buffer layer between wave-like TiO2and CuInS2determines the photosensitivity of the Ti/wave-like TiO2/In2S3/CuInS2thin structure. The In2S3and CuInS2are well-crystallized at 300oC. The CuInS2phase forms in In2S3layer due to Cu diffusion independent on the slight loss of sulfur. The CuInS2direct deposition on Ti/wave-like TiO2substrate can not exhibit photosensitivity. When CuInS2deposited on In2S3to form Ti/wave-like TiO2/In2S3/CuInS2structure, the short-circuit current and the open-circuit voltage increase with the thickness increase of In2S3layer while illuminated by 50 mW/cm2white light.
Numerical Modeling of Galvanic Corrosion Behaviors on Uranium Surface
Authors: Shi Ping An , Zhou Hong Liang
Published: May 2013

The Uranium and Titanium corrosion rates are described by a Tafel’s relationship, and the cathodic protection of Uranium is a function of a Wagner number. A numerical simulation of galvanic corrosion of Uranium surface under thin layer electrolyte is presented. The model considered that the effect of a circular defect and oxygen reduction and corrosion in the Uranium surface, the effect of electrolyte thickness and conductivity and defect radius on corrosion current distribution of Uranium with is investigated. The results shows that the corrosion rate at the center is non-uniform, and it could lead to the formation of a hemispherical-shaped pit. And the effect of radius is to increase the importance of the electrode kinetics relative to ohmic resistance, and to increase the potential difference between the center and edge of the Uranium surface, resulting in non-uniform corrosion current distribution.
Thickness Thinning of Epitaxial Graphene Grown on Carbon-Terminated 6H-SiC by Using Oxygen Plasma Etching
Authors: Hao Xin , Chen Yuan Fu , Li Ping Jian , Wang Ze Gao , Liu Jing Bo , Li Yan Rong
Published: May 2013

Oxygen plasma was utilized to etch the epitaxial graphene films grown on carbon-terminated 6H-SiC substrate. XPS spectra show that the intensity ratio between the graphene peak and SiC peak decreases with oxygen plasma etching time. It indicates that with increasing etching time from 0 to 42 s, the thickness of graphene dramatically decreases from eight to one monolayers following a first-order exponential decay function. Meanwhile, AFM images show that the ridges among domains are preferred to be etched by oxygen plasma and they will almost disappear after etched for 42 s. It indicates that the oxygen plasma will not decrease the mobility of graphene layer obviously when the graphene thickness is over two monolayers; however, further etching the graphene with thickness less than two monolayers will leads to significantly decrease the mobility due to the formation of many more defects.
Rheological Analysis of Oceanic Concrete Structure
Authors: Gao Rui , Yang Ling Qiang
Published: May 2013

Based on the normal H-K rheology model, a new rheological model containing fracture elements for concrete or rock cracked body is introduced. The method to ascertain rheology state is put forward. The new rheological model can change to Maxwell or Kelvin model to express the instantaneous failure, delayed failure state and the accelerating segment. The researching failure element method was used to study the crack propagation. Then the cracking elements were studied using rheology mechanics to solve the cracking time. At last a case study was given to validate the method is feasible.
Morphology and Structure of Epitaxial Pb(Zr0.52Ti0.48)O3/La0.8Ca0.2MnO3 Heterostructures Grown on Sr TiO3 Substrates
Authors: Hao Xin , Chen Yuan Fu , Wang Ze Gao , Zou Cheng , Li Yan Rong
Published: May 2013

Pb(Zr0.52Ti0.48)O3/La0.8Ca0.2MnO3 (PZT/LCMO) thin films were deposited onto SrTiO3 (STO) single crystalline substrates by pulse laser deposition (PLD). The AFM morphology results show that the LCMO ( PZT) layer is very smooth and homogenous with very low values of RMS roughness. The XRD results show that only the (00l) peaks are observed for both LCMO and PZT layers which are single crystalline and have an epitaxial relationship with STO substrates: PZT (001)//LCMO(001)//STO (001). The FWHM values of the (001) omega-rocking curves of the LCMO and PZT film were 0.276o and 0.565o, respectively, which suggests high crystalline quality of epitaxial PZT/LSMO LSMO heterostructures were grown on STO substrates.
BiVO4-TiO2 Nanocomposite: Synthesis and Photocatalytic Investigation
Authors: Rahimi Rahmatollah , Zargari Solmaz , Moghaddas Masoumeh Mahjoub
Published: May 2013

BiVO4composited with TiO2(BVO-T) nanoparticles was sensitized by tetrakis(4-carboxy phenyl)porphyrin (TCPP) dye (BVO-T/P) to efficiently utilize visible light in the photodegradation reaction. To investigate the photoactivity of this catalyst, its photocatalytic efficiency was compared to the pure TiO2, pure BiVO4, and BiVO4composited with TiO2in the destruction of methyl orange in the visible light. Furthermore, the kinetic of the MO degradation as well as the stability of BVO-T/P photocatalyst was investigated.
Electrodepositon and Properties of Ni-Diamond Composite Coatings
Authors: He Xiang Zhu , Zhang Wen Jun , Wang Yong Xiu
Published: May 2013

Ni-diamond composite coatings are conducted by electrodepositon. The crystal structure and surface morphology of the composite coatings were examined with X-ray diffraction (XRD) and scanning electron microscopy (SEM) and the mechanism of Ni-diamond co-deposition is conducted by catholic polarization and cyclic voltammetry method. The result reveals that diamond particles are successfully embed in Ni matrix and the coatings have an amorphous structure. Cyclic voltammetry indicate that nickel deposition process is an irreversible electrode reaction and cathode polarization curve shift towards positive with the increase of scan rates. Cathodic polarization curve shows that reduction potential of nickel to shift to more negatives with the addition of complexing agent and the slope of the polarization curve is decrease; The addition of brightener and dispersant hinder the deposition of Ni2+ and promote the growth of crystal nucleus; The join of wetting agents and diamond particles have no big influence on the deposition of nickel.
Study on Cr-Al2O3 Nano Composite Electrodeposition in Cr(III) Plating Bath
Authors: He Xiang Zhu , Huang Li Yong , Sun Xin
Published: May 2013

In this paper, structural and electrochemical characteristics of the Cr-Al2O3nano composite coatings were investigated. Cr-Al2O3nano composite coatings were electrodeposited in electrolyte containing nano Al2O3particles. The influences of nano Al2O3particles on the chemical composition, morphological and structural characteristics of the electrodeposited Cr-Al2O3nano composite coatings were investigated using energy dispersive X-ray spectroscopy, scanning electron microscopy and X-ray diffractometry. The electrodeposition behavior of Cr3+ion and the action mechanism of electrolyte components such as auxiliary complexing agent, wetting agent, nano Al2O3 in the process of Cr-Al2O3composite electrodeposition were investigated using the electrochemical measurement methods such as cyclic voltammetry and cathodic polarization. The results reveal that the nano Al2O3particles can be codeposited in the Cr matrix, micro crystal structure of the Cr-Al2O3nano composite coatings are obviously refined, Cr-Al2O3nano composite coatings are amorphous structure.
Homotopy Perturbation Method for Analysis Nonlinear Vibration of Double-Walled Carbon Nanotubes
Authors: Chang Lie Zhen , Pan Yu Tian , Ma Xin Mou
Published: May 2013

To obtain the approximately analytical solution of double-walled carbon nanotubes (DWNTs) nonlinear vibration. In this study, homotopy perturbation method (HPM) was used to solve nonlinear vibration equation of DWNTs. Novel and accurate analytical solutions for the frequency and displacement are derived. Comparison of the result obtained by the HPM with exact solutions reveals that only the first or second order approximation of the HPM leads to higher accurate solution.
New Preparation for Amorphous/Nanocrystalline Ni-Mo Alloys by Electrodeposition
Authors: Li Ning , Wang Lin Lin , Wang Xiao Ming , Chen Wei Zeng
Published: May 2013

The amorphous/nanocrystalline Ni-Mo alloys are obtained in alkaline nickel carbonate solution in this paper. By using X-ray diffraction (XRD) and scanning electronic microscopy (SEM) to testify microstructure and morphology of the deposits. It is found that the deposits are composed of amorphous and nanocrystalline structure phases. Compared with the nickel sulfate solution, the amorphous/nanocrystalline alloys are more accessible to be obtained in carbonate solution under the same conditions as the sulfate solution. The internal stress between the deposit and the basement is inexistent with the tiny granules and well-proportioned grains at the coating surface. The stability of the alkaline nickel carbonate solution is much better than the sulfate solution, and the deposit performance is relatively better and easy to be controlled.
Mean and Instantaneous Thermal Expansion of Uncoated and Ti Coated Diamond/Copper Composite Materials
Authors: Wang Qing Yun , Shen Wei Ping , Ma Ming Liang
Published: May 2013

Heat sink materials not only should have higher thermal conductivity, but also have smaller difference of thermal expansion with cooled material. diamond/copper composites were made by the powder metallurgy method. Vacuum slowly vapor deposition technique was employed to deposit a titanium film on diamond particles before mixing with Cu powder in order to improve the bonding strength between Cu and diamond particles during sintering. The thermal expansion of diamond/Cu d composite was measured in the temperature range from 50 to 600 °C. The results show that the titanium film on diamond improves the interfacial bonding and reduces the coefficient of thermal expansion (CTE) of Cu/diamond composites. The CTE of diamond/Cu composites decreases with increasing diamond volume fraction as the results of mixture rule and the intense restriction effect of diamond reinforcement on the copper matrix. The residual stresses and pores in the composites affect instantaneous thermal expansion of diamond/Cu composites.
Water Absorption and Tensile Strength of Coconut Filter Fibers/Polypropylene Composites
Authors: Suardana N.P.G. , Lokantara I. Putu , Piao Y.J. , Lim J.K.
Published: May 2013

In this study, we evaluated water absorption and tensile properties of coconut filter fiber reinforced polypropylene composites. The fibers were subjected to various immersion times for 0.5, 1, and 3 h in 0.5 % acrylic acid solution at room temperature and 0.5 h at 70 oC. The treated fibers were used as reinforcement of polypropylene composites. Water absorption of treated fiber composites was lower than those of untreated fiber composite. Boiling in water significantly affect water absorption rate of the composites. The tensile strength and elastic modulus of treated fiber are higher than untreated fiber. They show a decrease in tendency when the immersion time increased. Tensile strength and elastic modulus of composites with AA-treated at 70 oC fiber are the highest.
A CDM Model and its FE Implementation for 2D C/SiC Composite under Tension and Shear Loads
Authors: Li Jun , Jiao Gui Qiong , Wang Bo
Published: May 2013

2D C/SiC ceramic matrix composite (CMC) displays significant damage characteristic coupled with inelastic strain under tension and shear loads, which should be considered in the constitutive model. In this study, a continuum damage mechanics (CDM) model was proposed for this material, in which the process degradation of the material property was described by introducing a set of scalar damage variables, and the damage-coupling effect was also considered. Meanwhile, isotropic hardening theory was applied to form the evolution rule of inelastic strains. The model was then implemented into the UMAT in ABAQUS software and validated by comparison between the simulation and experiment results.
Biological Denitrification Using Slow-Release Carbon Source Composite Materials as Solid Carbon Source and Biofilm Carrier
Authors: Wang He Ming , Yang Fan
Published: May 2013

As lack of organic carbon source is a key problem for biological denitrification, hemp fiber, PBS, PLA and PE were selected as raw materials, then four kinds of slow-release carbon source composite materials were prepared by 35A-double-screw extruder and used for biological denitrification. Their performan- ces were detected through static and continuous experiments. The results showed that in the static experiments, release carbon abilities of HB20 and HB40 were both not good, their CODMnwere 5.42 and 12.83mg/L respectively; In the continuous experiments, NO3-N removal rate of HLE decreased from 57.9% to 13.1% within 30 days. HBE could cause a continuous release of dissolved organic compound. In the operation of 66 days, above 96.0% NO3-N was removed and NO2-N level was below 0.02mg/L when influent NO3-N =30.0mg/L and HRT=24h. HBE was the most suitable carbon source carrier material for biological denitrification.