bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Degradation and Microhardness Analysis of Polyene with Modified Oil Resin
Authors: Norizan Mohd Nurazzi , Mohamed Rahmah , Mohamad Ahmad Faiza
Published: March 2013

Thermal degradation of polyene synthesized from recycle polyvinyl chloride (PVC) and hardness of polyene coated with modified oil has been studied by thermogravimetric analysis (TGA) and microhardness test. The synthesized polyene from reaction of recycle PVC were varied from 30 minutes, 1 hour, 2 hours and 4 hours and their thermal stability has been analyzed. From differential thermal gravimetric, DTG curve, polyene from two hours reaction showed the highest degradation temperature up to 445°C due to degradation of polyene sequences. Microhardness test performed by Shimadzu DUH 211/DUH-211S dynamic ultra microhardness tester according to ASTM E384 showed that polyene derived from 2 hours PVC with modifed oil resin resulted in the highest microhardness ~ 107.99 MPa.
Low Temperature Synthesis and Characterization of Flower-Like ZnO Nanostructures
Authors: Tu Ya Fang , Fu Qiu Ming
Published: March 2013

Flower-like ZnO nanostructures have been synthesized via solution process using zinc nitrate and sodium hydroxide at very low temperature of 70 °C in 1h. The structure, morphology and optical properties of the product were characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy and photoluminescence. The flower-like ZnO nanostructures were composed of uniform nanorods, they were well crystallized with a hexagonal wurtzite structure, and showed a strong ultraviolet emission at 385 nm and a weak and broad yellow emission in the photoluminescence spectrum.
Phase Composition and Morphology of Pottery Stone Microcrystalline Powders Synthesized by Hydrothermal Method
Authors: Larpkasemsuk Amnouy , Chuayjuljit Saowaroj , Kashima Dujreutai Pongkao
Published: March 2013

Pottery stone (PTS) microcrystalline powders were synthesized by a hydrothermal method using two concentrations of NaOH solution (2 M and 4 M) at 60, 80 and 120°C for 8 h in a Teflon- lined stainless steel autoclave. The phase composition and morphology of the samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The major phase compositions of the as-prepared PTS powders appeared in the XRD patterns are all silicate compounds such as tridymite, crystobalite, quartz, feldspar, albite, sodium silicate, analcime, hydroxyl-cancrinite and sodium aluminium silicates, depending on the NaOH concentration and the reaction temperature. Moreover, SEM micrographs showed the spherical polyhedral particles ranging from 8 to 14 µm in diameters and needle-like particles with a mean aspect ratio of 5.7 that obtained by the hydrothermal treatment operated at 120°C using 2 M and 4 M of NaOH, respectively.
Control over Dispersion Efficiency of Nano-Size Zno Particles in Aqueous Medium: Correlation between Dispersant Molecular Weight and Particle Size
Authors: Suntako Rudeerat , Traiphol Nisanart
Published: March 2013

Aqueous suspensions of zinc oxide (ZnO) nanoparticles are prepared at 0.5 wt% solid content using polyacrylic acid (PAA) as a dispersant. Average particle sizes of the ZnO powder are 65, 175 and 225 nm and the dispersant molecular weights (MW) are 1.8k, 450k and 3000k g/mol. Particle dispersion and stability of the ZnO nanoparticles in aqueous suspensions are investigated to determine the efficiency of each PAA as a dispersant. It is found that the efficiency of PAAs depends significantly on their MW and size of the ZnO nanoparticles. At relatively low dispersant concentration, the PAA(1.8k) is the most efficient one for all ZnO nanoparticles. When the dispersant concentration and size of the ZnO nanoparticles increase, the PAA(450k) becomes the most efficient one. The PAA(3000k) is the worst dispersant in all conditions. This research provides a fundamental knowledge on relationship between particle size and dispersant MW, which is essential for producing a well-dispersed and highly stable aqueous suspension.
Joining Active Metals with Al2O3 by Use of Solders
Authors: Koleňák Roman , Prach Michal
Published: March 2013

The work deals with joining active metals as Ti, Zr and Hf with Al2O3ceramics. The solubility of these active metals in selected Sn and In based solders was studied at a selected soldering temperature. Capability of active metals to wet Al2O3ceramics and to form a diffusion bind was ascertained. Soldering was performed with Sn, Sn5Ag, In and In30Sn solders, which were enriched by an active element from metallic substrate of the joint in soldering process. Soldering temperature in vacuum varied from 770 to 870 °C and soldering time was selected from 8 to 20 min. It was found out that the most suitable metal for active solders is Ti, because it is dissolved in Sn solder already at temperature 780 °C. Wetting of ceramic Al2O3substrate and formation of a diffusion bond was achieved already at temperature 830 °C/8 min. Diffusion bond with Zr was formed just at temperature 870 °C/20 min. and it was impossible to form a diffusion bond with Hf.
First-Principles Calculations of Elastic Properties of HoBi and ErBi
Authors: Han De Ming , Zhang Gang , Zhao Li Hui
Published: March 2013

We present first-principles investigations on the elastic properties of XBi (X=Ho, Er) compounds. Basic physical properties, such as lattice constant, elastic constants (Cij), isotropic shear modulus (G), bulk modulus (B), Young’s modulus (Y), Poisson’s ratio (υ), and Anisotropy factor (A) are calculated. The calculated energy band structures show that the two compounds possess semi-metallic character. We hope that these results would be useful for future work on two compounds.
Multi-Parameter Linear Regression Analysis about the Experimental Results of Pervious Concrete Strength
Authors: He Xi Xi
Published: March 2013

In this paper, based on 28-day cubic compressive strength fcu and splitting strength fts of pervious concrete with different porosity, aggregate size and of cubic size, correlation analysis was conducted among these three factors and strength using the software of SPSS (Statistical Package for the Social Sciences), in which a logarithmic function was used to do linear regression fitting about the relationship among the three parameters and the strength and then a formula was proposed. The analysis result shows that there is a certain higher-order function relationship between the three influencing factors and the strength, and it is contribute to analysis the impact of three parameters on strength by using natural logarithm to linearize the relationship of parameters. Studies have shown that porosity is the main factor that affects both fcu and fts, and side length of the cube has a significant influence on fts but has no significant linear correlation with fcu. And fts may be more sensitive to cube size on linear correlation than fcu.
The Effect of pH Value on the Polycyclic Aromatic Hydrocarbons Degradation in Sludge during Biological Aerobic Fermentation Process
Authors: Yu Jie
Published: March 2013

The degradation of polycyclic aromatic hydrocarbons in sludge in aerobic fermentation process is affected by many factors, and the pile body pH value is one of the important factors. Through the test of mixing lime pile body regulating pH value (7.7, 8.2, 9), the polycyclic aromatic hydrocarbon degradation effect was researched under the different pH conditions and the same of the other aerobic fermentation conditions. The results showed that, pH=7.7 test device (not mixing lime ) on PAHs degradation effect was best, worst was the pH=8.2 test device, the sludge degradation of the polycyclic aromatic hydrocarbons effect is negative effect.
A SERRS Method for Coomassie Brilliant Blue Using Nanogold Aggregation Sol as Sunstrate
Authors: Wen Gui Qing , Yang Duo , Jiang Zhi Liang
Published: March 2013

In pH 6.6 Na2HPO4-NaH2PO4 buffer solution and in the presence of NaCl, nanogolds were aggregated to form stable aggregated-nanogolds (ANG). The molecular probe of coomassie brilliant blue G-250 (CBBG) adsorbed on the surface of ANG to form CBBG -ANG conjugates that produce the strongest surface-enhanced resonance Raman scattering (SERRS) peak at 1171 cm-1. Under the optimized conditions, the increased intensity ΔI was linear to CBBG concentration in the range of 0.29×10-7 - 4.68×10-7 mol/L, with the regression equation of ΔI = 0.86C - 17.1. A fast and sensitive method for trace CBBG was developed.
Resonance Rayleigh Scattering Spectra Property of Selenium Nanoparticles and its Analytical Application
Authors: Liang Ai Hui , Huang Shan Shan , Jiang Zhi Liang
Published: March 2013

In 0.1 mol/L HCl medium and the presence of 0.3% glycerin as stabilizer, selenium (Ⅳ) was reduced by thiourea to form selenium nanoparticles, which exhibited a strong resonance Rayleigh scattering (RRS) peak at 366 nm. The RRS peak intensity increased when selenium (Ⅳ) increased. The increased RRS intensity at 366 nm (ΔI366nm) was proportional to the selenium (Ⅳ) concentration (C) from 1 to 32 μg/L, with a regression equation of ΔI366nm= 222.99 C+74.69, and detection limit of 1.19 ng/L. This proposed method was applied to detect selenium in samples, with satisfactory results.
Resonance Rayleigh Scattering Effect of Immunonanosilver Aggreagations and its Application to Rapid Determination of Trace Hg(II)
Authors: Xu Li Li , Jiang Zhi Liang , Liang Ai Hui
Published: March 2013

Using PEG-10000 and sodium citrate as stabilizer, and NaBH4 as reducer, a stable nanosilvers (AgNPs) sol was prepared. In pH 6.6 phosphate buffer solution containing NaCl, the AgNPs were aggregated to large particles, which lead to resonance Rayleigh scattering (RRS) peak at 350 nm enhancement. Upon addition of cysteine, the peak decreased. The decreased value ΔI is linear to cysteine concentration in the range of 5-60×10-8 mol/L. Thus, a new RRS method was proposed for detection of cysteine.
Effect of Euphorbia Coagulum on Flexural Property of Polyester Banana Fiber Composite
Authors: Rai Bhuvneshwar , Diwan Rajinder K. , Kumar Gulshan
Published: March 2013

Presently composites made up of either both the binder and the reinforcing fibers are synthetic or either one of the material is natural or synthetic. In the present study coagulum (dried latex) of Euphorbia royleana has been used for replacing polyester resin as a natural binder in polyester banana fiber composite. The influence of different volume fraction of the coagulum in the composite is studied. It is observed that with the increase in the coagulum fraction, the flexural property of the polyester banana fiber composite increases. The flexural strength increase by 25% and flexural modulus by 15% at 40% of coagulum weight fraction. This study presents the possibility of preparation of composites using coagulum of Euphorbia latex. The developed composite may be used in partition walls, roof tiles, interior linings of automobiles, etc as wood substitute.
Preparation and Characterizations of Novel Ultrafiltration Membranes from Sulfonated Poly (Arylene Ether Sulfone)s
Authors: Zhang Jing Jing , Bu Hang , Chen Shou Wen , Bi Hui Ping , Hu Zhao Xia , Wang Lian Jun
Published: March 2013

Sulfonated poly(arylene ether sulfone)s (SPAES) with different sulfonation degree (DS) were synthesized through aromatic nucleophilic substitution polymerization, and subsequently used to prepare ultrafiltration membranes by the phase inversion method. The performance and morphological structures of the prepared SPAES membranes were investigated and evaluated for ultrafiltration applications. With DS of 3%, the prepared ultrafiltration membrane showed the largest water permeability with bovine serum albumin rejection over 99%.
Research Methods of Catalytic Oxidation on Methane in Conversion Process
Authors: Yang Xiao Min , Wu Wen Rong , Tang Qing Jie
Published: March 2013

The significance of catalytic conversion on Methane was summarized, the methods and mechanism of catalytic partial oxidation on Methane were elaborated, and the advance in catalyst application on Methane in the process of catalytic conversion was discussed and summarized.
Pricing Decision Study of Ecological Industry Chain Based on Uncertain Demand
Authors: Yu Hai Jie , Su Sheng
Published: March 2013

A two stages ecological industry chain was took as study background. The downstream buy amount is uncertain demand. Stock of byproduct is certain. There are two kinds of situations. Buy amount is higher or lower than byproduct stock. Price decisions of byproducts were studied based on game theory. Sequential game equilibrium (Stackelberg equilibrium) and cooperative game equilibrium (coordination in price decision) were obtained.
The Multivariate Nonlinear Regression Model of Zincificated Steel Resistance Spot
Authors: Wang Zhi Wei , Wang Ya Long , Zhang Dong Dong
Published: March 2013

In order to research welding technology of DX51D+Z cold rolled galvanized steel, using multivariate nonlinear regression orthogonal combination design method, adopted the shear load as quality indicators, counted welding current, electrode force, welding time, squeeze time and the interaction of them as factors, to built the nonlinear regression models, by adopting this model to forecast shearing load. The result shows that this model has high forecast precision.
Technical Development of Hybrid Rapid Tooling Technology
Authors: Kuo Chil Chyuan , Su Sheng Jie , Shiu Shiou Ru
Published: March 2013

The surface finish of fused deposition modeling (FDM) processed part is excessively rough due to stair stepping effect. In addition, the tensile strength of rapid tooling fabricated by FDM is inferior to that fabricated by plastic injection molding. A hybrid rapid tooling technology is developed to improve the surface roughness and increase the tensile strength of rapid tooling fabricated by FDM using epoxy-based composite in this work. Improvement rate of tensile strength of rapid tooling is 2.34 times of the add rate of epoxy-based composite. Surface roughness improvement rate of up to 92.94% can be achieved. Hybrid rapid tooling technology owns low manufacturing cost, simple manufacturing process and good flexibility.
Development of a High Efficiency Degassing System for Making Silicone Rubber Mold
Authors: Kuo Chil Chyuan , Huang Chuan Ming
Published: March 2013

Silicone rubber mold is regarded as an important method of reducing the cost and time to market in a new product development process. Commercial automatic vacuum machine is widely used to degas in the manufacturing of silicone rubber mold, but the cost of hardware is very expensive. A high efficiency degassing system is designed and implemented from regular vacuum machine. It is found that degassing process includes explosion phase, balance phase and convergence phase. The maximum saving in the degassing time is about 63.7%. The advantages of this system include reducing human error of operator, reducing noise and air pollutions derived from the vacuum pump.
Research on the Method of Determining Aircraft Spare Parts
Authors: Zhang Yi Gang , Li Tao , Chen Li , Liu Tao
Published: March 2013

Quantity determination of the Aircraft spares is affected by many factors, the indeterminate effect is not quantitative factors on the quantity of spare parts, analytic hierarchy process is applied to the quantity calculation of the aircraft spares. General principles of administrative levels to analyze law dealing with the aircraft spares calculation of multi factor problem is introduced, 5 influence factors is economy, importance, difficulty degree, affected, string etc. The use of analytic hierarchy process used in random spare parts calculation is illustrated.
Effect of Skin Depth on Hardness Profile of Gear Heated by Induction Using 2D Model
Authors: Barka Noureddine , Jelil Khelalfa Abdel , El Ouafi Abderrazak , Bocher Philippe , Brousseau Jean
Published: March 2013

This work is carried principally by simulation efforts using computer-modeling software (COMSOL). The developed 2D model includes the coupling between electromagnetic and thermal fields, and takes account of the nonlinear behaviour of material properties versus temperature. Several steps were followed to reach this goal. First, a 2D finite element model of a gear was developed in order to simulate the induced currents density and temperature distributions for various frequencies and external currents applied in the coil. Second, the temperature profiles were compared using the ratio between the skin depth and the teeth height. In geometry cases, it was possible to dose the power level of the medium (MF) and high (HF) frequencies to reach a desired uniform case depth. The MF and HF powers are simulated sequentially in order to better concentrate heat in the tooth tip and root of gear. The obtained results help process developers to select the proper parameters for the induction machine in order to achieve the desired hardness profile.
Exoskeleton Finger Rehabilitation Robot Dynamics Simulation Analysis
Authors: Wang Ji Rong , Yu Mei Li , Wang Yu , Song Jiang Wei , Li Tian Yi , Yang Li Li
Published: March 2013

In this paper, an exoskeleton mechanical finger for rehabilitation has been designed. It has two finger knuckles which are driven by two cylinders separately. In the simulation process of ADAMS, the two cylinder driving stems are set different movement speeds and then the two finger-knuckles can be tracked as specific trajectories. The joint force and the torque curve of the exoskeleton mechanical finger at the point of the two knuckles can be got at different cylinder driving speeds.
Numerical Simulation on the Working Process of a Lean Burn Natural Gas Engine
Authors: Feng Li Yan , Zhang Chun Huan , Xiong Chang Jun
Published: March 2013

The working process of a lean burn natural gas spark ignition engine was simulated with a 3-D CFD software package AVL-FIRE. Such simulations were made to analyze and understand the flow field, fuel/air mixture distribution, ignition and flame propagation. The simulations provide basis for the optimization of the combustion system of the engine. Two injection strategies for the pre-chamber enrichment were established and compared. The results indicate that with enrichment injection in the pre-chamber, the fuel/air equivalence ratio is precisely controlled in the range of 1.0 to 1.1, stable ignition in the pre-chamber is ensured, and fast initial flame propagation in main combustion chamber is realized.
Near Surface Research and Excitation Horizon Prediction Based on Old River Course of Xiaoqing River in Shan Dong
Authors: Zhang Guang De
Published: March 2013

Following deepened exploration and development in Shengli exploration area, seismic data requirements are also getting higher and higher. However, in recent years the difference of Xiaoqing river on both sides have made us know that the importance of this problem. In view of the above, this task is aimed at quaternary shallow of old river course within Xiaoqing River. Our analysis of lithology and sedimentary characteristics are using static cone penetration test and rock core exploration method, and we want to reappear near surface deposition of old river course within Xiaoqing River. The research is close combined with the exploration demand and theoretical study, so it has important theoretical and practical significance.
Improving Safety Management Efficiency in Large-Scaled Construction Company through Questionnaire Survey
Authors: Im Soo Bin , Kim Yu Ri , Kim Sang Chul , Shim Sang Oh , Choi Seong Woo
Published: March 2013

Construction industry is accident-prone industry with high percentage of occupational accidents against total number of employees, to prevent safety accident, a lot of safety management system has been developed and applied to construction industry, a safety manger’s time to inspect the construction site has rather decreased due to increase in burden of administrative work for safety management. As a result, there was a doubt on the efficiency of intensified safety management activities. Therefore, this study is aimed to investigate current safety management activities and propose a more practical and efficient management plan after analyzing strengths and weaknesses so far through a questionnaire survey.
An Experimental Study on Ultimate Behaviors of Double Shear Bolted Connections with Ferritic Stainless Steel
Authors: Kim Tae Soo , Kim Min Seung
Published: March 2013

Based on the existing test results of single shear bolted connection fabricated with cold-formed ferritic stainless steel, in this study, the experiment for double shear bolted connections with bolt arrangements(1×2, 2×2) and end distance parallel to the loading direction as main variables has been performed. Specimens were planed with a constant dimension of edge distance perpendicular to the loading direction, bolt diameter, pitch and gauge. Ultimate strength and fracture mode obtained from test results were compared with those predicted by current American and Japan design codes such as AISI and AIJ.
Characteristics of Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) in Gas and Particle Phase in April and July 2011 in Beijing, China
Authors: Cheng Xiao Liang , Xie Shao Dong
Published: March 2013

Presence of atmospheric PAHs in urban and suburban region (Beijing, China) was studied in April and July 2011. Forty-four pairs of gas and particle (TSP) phase samples were collected every six day by high volume (Hi-Vol) air samplers at four sampling sites, and determined separately by GC/MS based on USEPA Method TO-13A. Average total concentration (gas + particles) of PAHs (T-PAHs) was 135.1±49.0 ng/m3 and 181.2±40.9 ng/m3 in April and July, respectively. Gas phase PAHs (G-PAHs) was the major fraction, comprising 63–92% of T-PAHs. Lighter (2-, 3-, 4-ring) and heavier (5-,6-ring) PAHs were found predominantly in gas and particle phase, respectively. 2- to 6- ring PAHs contributed 10%, 53%, 26%, 7% and 4% of T-PAHs, respectively. Five major PAHs, naphthalene (NAP), fluorene (FLU), PHE, fluoranthene (FLA), and pyrene (PYR) contributed 70 – 90% of T-PAHs. G-PAHs increased significantly while PAHs in particle phase (P-PAHs) decreased from April to July. Volatilization from soil and more emission from power generation increase might explain the increase of G-PAHs, and the washout of P-PAHs along with particles might explain the decrease of P-PAHs. Given particulate organic carbon (OC) and elemental carbon (EC) being well correlated, P-PAHs was moderately correlated with OC and EC, suggesting that there were other mechanisms contributing to P-PAHs different from those of OC/EC. Significant correlation between P-PAHs with SO2 and NO2 suggested coal combustion and automobile exhaust to be contamination contributors.
Synthesis, Structural, Optical, and Magnetic Properties of Fe Doped TiO2 along with Different Concentration
Authors: Siddhapara Kirit S. , Shah D.V.
Published: March 2013

Nanocrystalline Fe-doped TiO2 was prepared by Sol-Gel technique, which was followed by freeze at-30°C temperature for 12hrs. The obtained Gel was thermally treated at 200,400,600 and 800°C. X-ray Powder Diffraction (XRD), Scanning Electron microscopy (SEM), UV-Vis Spectroscopy, Photo luminescence (PL) and EDAX was used to study its Structural and Optical properties. All Fe-doped TiO2 nanostructures show an appearance of Red shift relative to the bulk TiO2. The XRD pattern show the coexistence of major anatase phase and minor brookite phase for samples treated up to 600°C. Whereas at 800°C rutile is the only phase observed. All Fe doped TiO2 nanostructures show an appearance of Red shift relative to bulk undoped TiO2. The magnetic property by Gouy Balance of Fe doped TiO2 exhibit Peramagnetism at room temperature.
Theoretical Investigation of Electrical Transport Property of Co-Cr Liquid Binary Alloy
Authors: Thakor Pankajsinh B. , Sonvane Yogeshkumar A. , Patel J.J. , Jani Ashvin R.
Published: March 2013

Electronic transport property like electrical resistivity (ρ) of Co-Cr liquid binary alloy is calculated using Faber-Ziman formulation. To describe electron-ion interaction we have used newly constructed parametric free model potential along with Ashcroft-Langreth (AL) partial structure factor. To see the effect of exchange and correlation effect on electrical resistivity, we have used different local field correction functions like Hartree, Taylor and Sarkar et al. From present results, it is seen that good agreements between present results and experimental data have been achieved. Lastly we conclude that our model potential successfully produces the data of electrical resistivity (ρ) of Co-Cr liquid binary alloy.
Theoretical Investigation of Atomic Transport Properties of 4d Transition Metals in Liquid Phase
Authors: Thakor Pankajsinh B. , Sonvane Y.A. , Jani Ashvin R.
Published: March 2013

Present article deals with atomic transport properties like self-diffusion coefficient (D) and viscosity coefficient (η) of 4d transition metals in liquid state. To describe structural information we have used different reference systems like Percus - Yevick Hard Sphere (PYHS), One Component Plasma (OCP) and Charge Hard Sphere (CHS) systems alongwith our newly constructed parameter free model potential. To see the effect of different correction functions on atomic transport properties, we have used different local field correction functions like Hartree (H), Vashishta-Singwi (VS), Hubbard-Sham (HS), Sarkar et al (S), Ichimaru-Utsumi (IU), Taylor (T) and Farid et al (F). From the present results we conclude that our newly constructed model potential successfully calculated atomic transport properties of 4d transition metals in liquid phase.
Dielectric and Electrical Properties of Binary Mixtures of Anisole and Some Primary Alcohols in the Frequency Range 20 Hz to 2 MHz
Authors: Chaube Hemantkumar A. , Rana Vipinchandra A.
Published: March 2013

The complex relative dielectric function ε*(ω) = ε-jε of binary mixture of anisole (AN) with methanol (MeOH) ,1-propanol (1-PrOH), 1-butanol (1-BuOH), 1-heptanol (1-HeOH) of varying concentration have been measured using Precision LCR meter in the frequency range 20 Hz to 2 MHz at 303 K. The electrical/dielectric properties of the liquid samples are represented in terms of intensive quantities namely, complex relative dielectric function ε*(ω), electrical modulus M*(ω), and extensive quantities, i.e. complex admittance Y*(ω) and complex impedance Z*(ω). All of these presentations are used to explore various processes contributed in the electrical/dielectric properties of the mixtures of polar-polar liquids.
Experimental Investigation on Core Shell Nanocomposite of Cr1-xVxS2
Authors: Gangopadhyay Arnab , Sarkar Aditi , Sarkar A.
Published: March 2013

Electrical and optical character of nanostructured Cr1-xVxS2 is studied here. This sulphide based nanoClusters (NC) was developed through chemical sol-gel route using (NH4)2Cr2O7 and NH4VO3 as active reagent and biopolymer gum acacia is used as capping agent. Core-shell NC has developed with sequential addition of active reagents in sulphation process. It is also possible to develop another type of core shell NC by reversal of the sequence of added reagents, i.e. interchanging the core and shell part. Experimental investigation including UV-VIS spectroscopy, dc current-voltage characteristics (CVC) have carried on. The results of CVC at room temperature (RT) show the distinctive features of localized energy levels. UV-VIS spectroscopic analysis shows absorption peak is blue shifted due to quantum confinement of nanoparticles. Overall appearance of optical absorption curve is completely different for two NCs. Peak positions are different for two types of core shell NC which confirms that the constituent materials of core and shell of two NC s has interchanged.
Surface Micro Topographical and Dielectric Studies of Cholesterol Crystals
Authors: Vyas Poorvesh M. , Joshi Mihir J.
Published: March 2013

Cholesterol is a main component in mammalian cell membranes and lipoproteins. High level of cholesterol in blood can damage arteries and potentially linked with cardiovascular diseases. Cholesterol is also major constituent of gall stones. Cholesterol crystals were grown by single diffusion gel growth technique using neutral silica gel set by acetic acid. Solution of cholesterol prepared in acetone was poured as a supernatant solution on set gel. Transparent, thin, platelet type crystals were grown. Powder XRD and FT IR studies were carried out for the confirmation of crystal system and chemical bonding. The surface micro topographical study was carried out by using SEM and AFM and interesting features were observed. As cholesterol possesses high dielectric constant, it functions as an insulting cover for the transmission of electric impulses in the nervous tissues; therefore, the dielectric study was carried to understand its dielectric behavior in the frequency range from 50 Hz to 5 MHz. The dielectric constant decreased as the frequency of applied field increased. The a.c. conductivity and a.c. resistivity were also calculated.
Preparation and Characterization of N-CdS Thin Films and its Schottky Barrier
Authors: Patel K.D. , Hingarajiya Keyur S. , Patel Mayur M. , Pathak V.M. , Srivastava R.
Published: March 2013

Cadmium sulphide (CdS), a member of group II-VI semiconductors is one of the promising materials from its applications point of view. The present investigations are about the preparation, structural and optical characterization of CdS thin films and their use as Schottky diode with Aluminum. Thin films of CdS having thickness around 700nm have been deposited by thermal evaporation. The chemical composition of the deposited CdS thin films has been made using EDAX technique. The structural characterization of this films was carried out using XRD. The structure of CdS after the deposition was found to be Cubic. Also, the lattice parameters were evaluated from the XRD data. From TEM of CdS thin films, the polycrystalline nature was confirmed. Optical characterization has been carried out using UV-VIS-IR spectroscopy. The direct as well as indirect band gaps obtained are 1.64eV and 1.48eV respectively. Schottky junctions were formed by a thermal vapor-deposition of 500nm Al films on pre-coated CdS glass substrates. Diode parameters, such as the zero bias barrier height φb0, the flat band barrier height φbf and the ideality factorη, were calculated using thermionic emission theory at room temperature.
Transport Properties of Ru1Sr2Gd2-xCexCu2O10  Compounds
Authors: Roy A. , Jamadar T.A. , Ghosh Ajay Kumar
Published: March 2013

We have synthesized Ru1Sr2Gd2-xCexCu2O10 (Ru-1222) materials using several concentrations of Ce. All ruthenocuprate compounds have been characterised by using standard X-ray diffraction (XRD) and Scanning Electron Micrographs (SEM). The concentration of Ce affects transport properties drastically. Compounds with x=0.5 remain nonsuperconducting with moderate resistivity even after annealing in different conditions. Enormous change in the normal state resistivity has been observed in different annealing conditions of Ru-1222 with x=0.5. Superconducting properties have been observed in compounds with x=0.65. The highest critical temperature obtained is 27.5K for x=0.65. In addition, the duration of annealing in flowing oxygen is found to be effective in changing the normal state resistivity for x=0.65.
Enhanced Dielectric Permittivity of Nh4H2Po4/Polyvinyl Alcohol Composites at Low Percolation Threshold
Authors: Uddin Jamal , Chaudhuri B.K.
Published: March 2013

A new kind of two phase ammonium dihydrogen phosphate (NH4H2PO4 or ADP)/polyvinyl alcohol (PVA) composite films have been prepared by solution cast technique. Significant enhancement of dielectric permittivity (~442) of ADP/PVA composites are observed at low ADP concentration (fADP fC ~5 wt %) which is the percolation threshold value estimated from the concentration dependent transport and dielectric data. Nearly 85 times increase in dielectric permittivity compared to that of the bare PVA film in the composite film around fC with low loss (~0.14) at 1 kHz and room temperature is observed. The present ADP based PVA composite material might be processed for application in devices.
Electrical Resistivity of Liquid Al-Mg Binary Alloys
Authors: Joshi Mitesh , Kumar Manjul , Gajjar P.N. , Thakore B.Y. , Jani Ashvin R.
Published: March 2013

The knowledge of the physical properties of liquid Al-Mg binary alloys is of high scientic and practical importance. The Ziman formalism is used to study the concentration dependent electrical resistivity of liquid Al-Mg alloys through an electron-ion potential. Partial structure factor is calculated by using Ashcroft-Langreth equation. The results are compared with experimental findings and the effect of screening function on electrical resistivity is discussed. This reveals that the resistivity data of liquid Al-Mg system are in qualitative agreement with the nearly-free electron picture.
Fabrication and Application of Thin Film Semiconductor Sensors for the Detection of Volatile Organic Compounds
Authors: Vaishnav V.S. , Patel S.G. , Panchal J.N.
Published: March 2013

Volatile Organic Compounds (VOCs) are highly reactive, often mixed with interfering gases and more importantly, their vapours in the gaseous form respond to the gas sensor devices. Oxide semiconductor based thin film gas sensors play vital role in detecting, monitoring and controlling the presence of hazardous and harmful gases in the environment at very low concentration and hence are tested for the detection of harmful or industrially important VOCs. The demand of sensitive as well stable gas/vapour sensors for direct sensing application has increased the importance of In2O3:SnO2 based semiconductor materials. The paper presents the fabrication aspects of thin film gas sensors based on x1In2O3:x2SnO2 compound and also their application for the detection of some important volatile organic compounds. Thin films of x1In2O3:x2SnO2 were deposited using Thermal Evaporation technique and under the optimized fabrication conditions, the vapour sensors were prepared and mounted on the proper contact jig. Their response to the presence of Volatile Organic Compounds like CCl4 was examined. The stability, the sensitivity and the response time of the sensors were studied for the different concentrations of test vapours.
Mechanical Properties of Cabbage-Based Edible Films
Authors: Wang Xiao Xuan , Zhou Jing , Wang Zhe , Niu Yan Qing , Ma Zhong Su
Published: March 2013

Effects of drying time, drying temperature, plasticizer and thickening agents on the mechanical properties of cabbage-based edible films were investigated. Films plasticized with glycerol exhibited significantly effect on mechanical properties. Drying time and temperature could show significantly effect on moisture content of the films. Thus, the optimal technology stuff ratio (CMC-Na :gelatine :glycerol :cabbage slurry) was 0.6 :0.3 :3 :96.1. The drying temperature was 55°C, and the drying time was 6.5hrs. The achieved cabbage-based edible films had original flavor, color and suitable strength.
Gas-Selective Permeability of Soy Protein Isolate Film
Authors: Wang Zhe , Wang Xiao Xuan , Zhou Jing , Ma Zhong Su
Published: March 2013

Gas-selective permeability of films obtained from soy protein isolate (SPI) solutions at pH 12 was discussed. The modification treatments (ultrasonic, microwave and ultrasonic/microwave assisted treatment) was carried out to regulate oxygen and carbon dioxide barrier properties of SPI films, further control gas-selective permeability of SPI films in this work. In addition, all films obtained were flexible and transparent. Gas-selective permeability coefficients of SPI film was from 0.39 to 1.25, as indicated that gas-selective permeability of SPI film could be regulated according to the actual needs of food systems.
Mechanical Properties of Methylcellulose-Based Films Containing Stearic Acids
Authors: Zhong Tian , Lian Zi Xuan , Wang Zhe , Niu Yan Qing , Ma Zhong Su
Published: March 2013

The effect of the homogenization conditions of the film-forming emulsions on the mechanical properties of Methylcellulose (MC)-based films containing stearic acids (SA) was studied. For this purpose, the initial emulsions were prepared in different dry matter ratios and treated by different homogenization methods. The mechanical properties, including elastic modulus (EM), tensile strength (TS) and elongation (E) became worse with the increase of the SA content. Then the mechanical properties were compared as a function of the polyethylene glycol 400 (PEG-400) contents. As a plasticizer, the increasing of PEG-400 could improved E greatly, but EM and TS both declined slightly. And finally, when homogenization conditions were more intense, EM and TS increased significantly while E showed a fairly smooth curve.
Influence of Contaminative Bacteria during Cultivation of Chlorella pyrenoidosa in Soybean Processing Wastewater
Authors: Zhong Yun Na , Zhang Ya Lei
Published: March 2013

Bacteria pollution is easy to happen during the treatment of wastewater by Chlorella pyrenoidosa (C. pyrenoidosa). And it is the key technical problem in the engineering applications. It is necessary to find out the influence of bacteria during the process, and then formulate the control project of bacteria pollution. This paper mainly studied on the relationship between C. pyrenoidosa and bacteria, during the treatment of bean products wastewater. Comparing those relationship between three stains of bacteria and C. pyrenoidosa, we found that three stains of bacterial all have adverse impact on the growth of chlorella and adipose accumulate. And those three stains of bacterial have no definite influence on C. pyrenoidosa. According to the above results, the control of bacteria during the wastewater-treatment by C. pyrenoidosa should be based on the type of wastewater and the follow-up using of chlorella.
Influence of the Microwave and Ultrasonic Synergistic Effect on Properties of Methylcellulose/Stearic Acids Films
Authors: Zhong Tian , Lian Zi Xuan , Wang Zhe , Niu Yan Qing , Ma Zhong Su
Published: March 2013

The Influence of the microwave (MW) and ultrasonic (US) synergistic effect on mechanical and water vapor barrier properties of methylcellulose (MC)/stearic acids (SA) films was studied. For this purpose, the initial emulsions were prepared and treated in a MW and US combination reaction system. The water vapor permeability (WVP) of the films was determined, as well as the mechanical properties. As a result of the extending of MW and US treatment time, the WVP of MC/SA films declined significantly. And the tensile strength (TS) and elongation percentage at break (E) were also affected by the treatment greatly. When the treated time was 20 min, the highest TS and E were observed.
Catalytic Conversion of Tar Compounds from Biomass over Modified Ni/Olivine Catalysts
Authors: Zhang Chang Sen , Li Zhi Jun , Xu Xing Min , Yang Li , Zhang Rui Qin
Published: March 2013

This study investigated the improving catalytic effects during tar catalytic reforming by impregnated NiO and CeO2 onto olivine, and the further reduction of carbon deposition on the catalysts was achieving by the addition of MgO. A series of characters of the catalysts were tested by XRD, TPR and TPD. The experimental results showed the addition of MgO could improve the resistance to carbon deposition and had demonstrated higher reaction activity at higher temperature and lower water-carbon ratio. The activities of catalysts were not only related to the impregnating order of the promoters NiO and CeO2 but also to the water (steam)-carbon ratio (S/C). Those catalysts impregnated Mg, Ce and Ni in order could achieve highly disperse sites and further promote the interaction between active sites and carriers. Furthermore, those catalysts also had higher reaction activity and better anti-coking abilities under low water (steam)-carbon ratios.
Acaricidal Activities of Albizzia julibrissin Durazz Extracts against Tetranychus cinnabarinus (Acari: Tetranychidae)
Authors: Wang D.D. , Jia F.L. , Chen J. , Yu W.J. , Dai G.H.
Published: March 2013

Extracts of stems and leaves of Albizzia julibrissin Durazz by tested for their acaricidal activities on female adults of Tetranychus cinnabarinus in the culture room condition. The results showed that 70% ethanol extract had an acaricidal activities with 98.72% adjusted mordality at a concentration of 10mg ml-1 after 24 h of treatment, and its LC50 (concentration at which 50% of the mites died) value was 2.06mg ml-1. The 70% ethanol crude extract was partitioned by the liquid-liquid extraction method. The activity of each partition was tested. The results showed that the most active compound was found in the n-butanol phase, and that the butanol partition owned 98.56% adjusted mortality at a concentration of 10mg ml-1 and its LC50 value was 8.27mg ml-1. In addition, the butanol partition was further tested for its ovicidal activity against eggs of T. cinnabarinus, and the LC50 value was 11.21mg ml-1 at the concentration of 20 mg ml-1 after 24h of treatment. The results of this present work indicated that the extract of A. julibrissin had both acaricidal and ovicidal activity against T. cinnabarinus, and the active compound’s polarity is relative strong, which will be useful for the active compound further isolation. The present results will be a base for developing a phytochemical miticide from the A. julibrissin extract.
Field Emission Model of CNT Based Ionization Gas Sensor
Authors: Mahmood Salman , Burhanudin Zainal Arif , Hamid Nor Hisham
Published: March 2013

A new model to study the gas detection mechanism of carbon nanotube (CNT) based ionization gas sensor has been developed. The model incorporates the effect of electron field emission due to the presence of CNT. The model is then embedded in the standard Particle-In-Cell / Monte-Carlo-Collision (PIC-MCC) codes. This enhanced PIC-MCC codes serve as a tool to optimize CNT based ionization gas sensor. The functionality of the new model is validated by running simulations of DC discharges in argon and comparing the results with published experimental and simulated works. From the simulation, one order of magnitude decrease in the breakdown voltages and three orders of magnitude faster response time was observed.
Changes in Physical and Antioxidant Properties of Nanostructured Zingiber officinale (Ginger) Rhizome as Affected by Milling Time
Authors: Norhidayah A. , Noriham A. , Rusop Mohamad
Published: March 2013

In this study, Zingiber officinale (ginger) rhizome nanoparticles were prepared using a planetary ball milling process and the effect of prolong milling time up to 8 hours on the physical and antioxidant properties has been investigated. The particle size was successfully reduced to 222.3nm after 4 hours of milling process but agglomerated nanoparticles were observed for sample that was continuously milled. Sample milled for 4 hours showed higher Total Phenolic Content (TPC) (356.06 mgGAE/g extract) as well as Total Flavonoid Content (TFC) whereas lowest value shown by sample milled for 8 hours. The inhibition of DPPH reached up to 60% for all tested nanostructured ginger except very low percent of inhibitory shown by sample milled for 6 hours. The IC50 concentration for DPPH inhibition was 800ppm for sample milled for 2 hours, 400ppm for 4 hours and1000ppm for sample milled for 8 hours. However sample milled for 8 hours showed significantly (p<0.05) greater Ferric Reducing Antioxidant Power (FRAP) among other tested samples.
Electrical and Structural Properties of ZnO/TiO2 Nanocomposite Thin Films by RF Magnetron Co-Sputtering
Authors: Saurdi I. , Mamat Mohamad Hafiz , Rusop Mohamad
Published: March 2013

In this study, the ZnO/TiO2 nanocomposite thin films were prepared by RF Magnetron co-sputtering ZnO and TiO2 targets at different deposition times from 30-75 minutes. The electrical and structural properties ZnO/TiO2 nanocomposite thin films were characterized by I-V measurement, atomic force microscopy (AFM) and field emission scanning electron microscopy (FE-SEM). The electrical characteristics of nanocomposite films revealed that the conductivity of thin films increases as the thickness increase due to the improvement in surface contact between particles as well as photocatalytic activity. High conductivity at 1.67x10-4 S/cm and lowest resistivity about 5.14x104 Ω/cm were obtained for 75 minutes deposition time. Atomic force microscopy (AFM) showed particle size of ZnO/TiO2 thin films varied from 27nm to 51nm with an increasing in deposition time with granular shapes structures were observed from field emission scanning electron microscopy (FE-SEM).
Surface Morphology of Seeded Nanostructured ZnO on Silicon by Sol-Gel Technique
Authors: Eswar Kevin Alvin , Ab Aziz Azlinda , Rusop Mahmood Mohamad , Abdullah Saifollah
Published: March 2013

Nanostructured ZnO as a seeded was prepared by sol-gel technique on p-type silicon in various low molarities. Zinc acetate, Diethanolamine (DEA), and isopropyl were use as starting material, stabilizer, and solvent respectively. Atomic Force Microscopy (AFM) analysis shows smooth surface and uniform layer were produced in low molarities of precursor. The surface morphology of nanostructured ZnO was analyzed by Field Emission Scanning Electron Microscopic (FESEM). It is found that the nanostructured ZnO were successfully deposited on the silicon substrate with size ~10 nm to ~35 nm. Photoluminescence spectroscopy was employed to study the band gap in room temperature. It shows that very low intensity of PL in 0.05m and 0.1 m. PL intensity become more obvious starting from 0.15 m of precursor concentration.
Optical Properties and Morphology of Al Doped Zinc Oxide Thin Film Exposed on Wet and Dry Conditions
Authors: Razali S.A. , Mamat Mohamad Hafiz , Berhan M.N. , Rusop Mahmood Mohamad
Published: March 2013

The optical properties and morphology of Aluminum (Al) doped Zinc Oxide (ZnO) thin films prepared by sol-gel method have been investigated. The thin films were prepared at annealing temperature of 550 OC and have been exposed under wet and dry conditions. UV-Vissmeasurements have been carried out to investigate the optical properties while Scanning Electron Microscope (SEM) to investigate morphology. The grain size of films was increased with increased annealing temperature. The average optical transmittance became about 80% in the visible and had sharp ultraviolet absorption edges at 380 nm. The absorption edge analysis revealed that the optical band gap energy for the films was ~ 3.26 eV. The surface morphology in increasing annealing temperature has a big size and less porosity between particles.
Raman and Electrical Analysis of Iodine-Doped Amorphous Carbon Thin Films
Authors: Fadzilah A.N. , Kamaruzaman Dayana , Rusop Mahmood Mohamad
Published: March 2013

Iodine doped amorphous carbon (a-C: I) thin films were prepared by using Thermal Chemical Vapor Deposition (CVD) with deposition temperature ranging from 5000C to 7000C. The physical and electrical properties of deposited a-C:I thin films were characterized by Raman spectroscope and Solar Simulator system. The presence of 2 peaks known as Raman D peaks and Raman G peaks ensure the amorphous structure of carbon (C). As deposition temperature increase, the ID/IG ratio shows difference value, which indicates the effects of the temperature towards the a-C: I structures. An ohmic graph was obtained for the IV measurement, and the conductivity varies from 10-4 to 101 Scm-1. The photoresponse was also determined for all samples. As a reference, an undoped a-C thin film was prepared to differentiate the characteristic between a-C and a-C: I.