bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Roughness Optimization of Wire Electrical Discharge Machining Using ABC Algorithm
Authors: Tharian Bibin K. , Kuriachen B. , Paul Josephkunju , Elson Paul V.
Published: June 2015

Wire electrical discharge machining is one of the important non-traditional machining processes for machining difficult to machine materials. It involves the removal of material by the discrete electric discharges produced between the inter electrode gap of continuously moving wire electrode and the work piece. The ability to produce intricate profiles on materials irrespective of the mechanical properties made this process to be widely used in industries. The present study investigates the relationship of various process parameters in WEDM of AISI 202 stainless steel with brass electrode.The experiments were planned according to Taguchi’s L18 orthogonal array and experimental models were developed. The important process parameters identified for the present study were pulse on time, peak current, pulse off time, wire feed, wire tension, dielectric flushing pressure, servo feed and gap voltage. The surface roughness of the machined surface was measured as the process performance measure. Analysis of variance test has also been carried out to check the adequacy of the developed models and to identify the level of significance of each process parameters. In addition to the developed models, ABC optimization has been performed to identify the optimum parameter combination for minimum surface roughness and the obtained optimal process parameters are peak current 11 A, pulse on time 100 μs, pulse off time 49 μs, wire feed 4 m/min, wire tension 10 N, flushing pressure 12 kg/cm2, servo feed 2100 mm/min and set gap voltage 30 V. Finally the results were verified with the experimental results and found that they are in good agreement.
Multi Response DEA-Based Taguchi Optimization of Process Parameters on AA8011 Friction Stir Welded Aluminium Alloys
Authors: Palani K. , Elanchezhian C. , Bhaskar G.B.
Published: June 2015

In this investigation, an attempt using data envelopment analysis based Taguchi method, is involved in solving the multi-response optimization of the process parameters of rotational speed, transverse speed, tool tilt angle with different tool pin profiles on the stir zone evolution in AA8011 Aluminium alloys. Three different tool pin profiles (hexagonal, pentagonal pin profiles of High Carbon High Chromium steel and Hexagonal tool pin profile of H13 steel) have been used to make the joints at the different combination of process parameters using L9 orthogonal array. The Vickers hardness and Impact strength are measured to optimize the process parameters using DEA based Taguchi method. It is found that the optimum conditions of rotational speed 660 RPM, transverse speed of 30 mm per minute and tilt angle of 2 degrees with the hexagonal tool pin profile of High Carbon High Chromium steel yielded a good quality weld.
Quality Improvement of Sugar by Two Factor Factorial Experimentation in Optimization of Quantity of Lime and Sulphur Added in the Juice Sulphitation Process of a Sugar Plant
Authors: Rajkumar A. , Malliga P.
Published: June 2015

Sugar industry is one of the vital sectors in improving the economy of any country. But, sugar industries are striving hard to increase their profitability due to high cost of sugar production accompanied with low selling price. Without resorting to radical restructuring of sugar plant, but through proper planning, annual savings can be improved. One of the artifices to address this issue is through improving the quality of sugar so that selling price can be increased which in turn generates more revenue to the plant. The Juice Sulphitation process, as applied in the manufacturing of sugar, is a subject of such wide-spread interest. The mixed juice from the mills contains soluble and non-soluble suspended non-sugars. These impurities are to be precipitated by the judicious and controlled addition of Milk of Lime (CaO) and subsequent neutralization by Sulphur Dioxide (SO2) gas. This paper attempts to improve the quality of sugar by optimizing the quantity of lime (in the form of milk of lime) and sulphur (in the form of SO2 gas) added in the juice sulphitation process of a sugar plant. Two factor factorial experimentation was adopted to obtain an optimal combination of lime and sulphur quantities. Data of Transmittancy test on sugar juice was collected by varying the quantities of lime and sulphur. Analysis of Variance (ANOVA) table was plotted which explored the significant effects of individual treatments and interaction effects. Further to this, comparison of treatment means was carried out to find out the best treatment combination values for achieving the optimal quality of sugar from sugarcane.
Applications of Super Strongly Perfect Graph for Manufacturing System towards a Leaner Structure
Authors: Jeya Jothi R. Mary
Published: June 2015

Some restructuring decisions are conceptualized which reflect the aim of the organization to gradually evolve the manufacturing system towards a leaner structure. This is done by way of defining simplified process so that lesser hindrance in terms of cycles of interactions is found. The reframing decisions are given by five restructured configurations of the manufacturing system. Models using graph theory are developed for original configuration and each of the new reframed configurations and the resulting structural characterization information is used to compare the structure of restructured configurations with the original configuration. A graph G is Super Strongly Perfect (SSP) if every induced sub graph H of G possesses a minimal dominating set that meets all the maximal cliques of H. A study on some classes of super strongly perfect graphs like wheel and double wheel graphs (in which each graph represents structure of some manufacturing system) are given.
Optimization of Two-Stage Hybrid Flow Shop Scheduling Problems Using Genetic Algorithm
Authors: Saravanan M. , S Sridhar , Harikannan N.
Published: June 2015

The two-stage Hybrid flow shop (HFS) scheduling is characterized n jobs m machines with two-stages in series. The essential complexities of the problem need to solve the hybrid flow shop scheduling using meta-heuristics. The paper addresses two-stage hybrid flow shop scheduling problems to minimize the makespan time with the batch size of 100 using Genetic Algorithm (GA) and Simulated Annealing algorithm (SA). The computational results observed that the GA algorithm is finding out good quality solutions than SA with lesser computational time.
Taguchi Based Optimization of Engine Parameters Using Nanocatalyst with Blends of Biodiesel
Authors: Ganesan S. , Mahalingam S. , Eluri Vamsi Krishna , Balaji A.
Published: June 2015

Diesel is a primary source of fuel consumed around the globe. Diesel, being a fossil fuel is expected to get over by 2050. Diesel operated vehicles normally emits high level of poisonous gases like NOx, CO2, HC etc. During the various researches, it was being found that vegetable oils exhibit the properties closer to diesel. Few changes in the properties of vegetable oils have resulted in efficient results and allowed us to replace diesel. The present work investigates the emission of diesel engine at various parameters, when lemongrass oil is blended with diesel in various proportions at different levels of injection pressure. The diesel engine was tested on load condition of 25%, 50%, 75% and 100%. Whereas ,injection pressure is varied from 200 to 220 bar at an interval of 20 bar with 10BD, 20BD and 30BD blends of biodiesel. Very small amount of nanocatalytic substance (MgO) is being used i.e. 15ppm, 30ppm and 45ppm to enhance the combustion properties of bio-fuel. The results Shows reduction in NOX HC and CO without sacrificing fuel efficiency. These confirmation results proves that good agreement of predicted values.
Feasibility Analysis of Recycling and Disposal of Spent Lithium-Ion Batteries in China
Authors: Jiang Jing Jing , Zeng Xian Lai , Li Jin Hui
Published: June 2015

Lithium-ion battery (LIB) is significantly changing the landscape of human life. The feasibility of recycling and disposal of spent LIBs was proposed based on the study of their forecasted demand and distribution characteristics in China. The yearly processing capacity of recycling and disposal facilities of spent LIBs on a nationwide scale were estimated to be at least 50 kilotons. The recycling and disposal facilities should be established in the southeastern coast areas of China, which generated high-density spent LIBs. Beijing was chosen as a city case study to discuss the demand forecasting and present one detailed construction planning of spent LIBs recycling. The obtained thoughts and results can contribute to the recycling and disposal facilities of other Chinese megacities.
Tensile and Dielectric Properties of Calcium Copper Titanate Filler in Epoxy Composites
Authors: Saidina D.S. , Mariatti M. , Juliewatty J.
Published: June 2015

Polymer-ceramic composites have been pursued as the most promising dielectric materials for embedded capacitors in the organic package. In this study, ceramic fillers such as Calcium Copper Titanate (CCTO) was used to produce epoxy thin film composites for the purpose to replace capacitor made of ceramic materials. Spin coating technique was used to produce epoxy thin film composites. The effect of fillers loading on tensile and dielectric properties of the epoxy thin film composites were determined. Results showed that epoxy thin film with 20 vol% filler loading showed good dielectric properties. However, an increase of the fillers content caused reduction in the tensile properties due to filler agglomeration and voids. Dielectric constants and dielectric losses of epoxy/inorganic composite films generally increase with addition of filler.
Structural, Morphological and Electrical Characteristics of Sol-Gel Prepared Lithium Triflate - Alumina Composite Electrolyte
Authors: Dzulkurnain Nurul Akmaliah , Mohamed Nor Sabirin
Published: June 2015

The objective of this work is to study the structural, morphological and electrical characteristics of lithium triflate-alumina composite electrolytes which were prepared via sol-gel technique. For this purpose, the composite electrolyte pallet samples which were sintered at 300 °C for four hours were subjected to X-ray diffraction, scanning electron microscopy, impedance spectroscopy and transference number measurement. X-ray diffraction spectra and scanning electron micrographs indicated that the crystalline alumina was distributed over the amorphous lithium triflate phase implying that the two-phases of microstructure (lithium triflate and alumina) interspersed each other. The highest ionic conductivity of 2.86 × 10-3 S cm-1 at room temperature was obtained for the sample with 60 mol % alumina. Temperature dependence of conductivity study was performed in the 303 K to 423 K temperature range and the trend of conductivity-temperature plot suggested that the increase in conductivity was due to the increase in migration rate of ions with temperature. The non-Arrhenius plot of the conductivity-temperature was due to continuous freezing of cations within the amorphous triflate medium. The value of ionic transference number indicated that the majority charge carriers in this composite electrolyte were ions while the value of Li+ transference number suggested that the majority of the ions were anions.
Characterisations of Palm-Based Polyurethane Solid Polymer Electrolyte
Authors: Daud Farah Nadia , Ahmad Azizan , Badri Khairiah Haji
Published: June 2015

Palm kernel oil based polyurethane (PU) electrolyte was prepared via prepolymerization method. The PU films was synthesized at 200/200 and 75/121 for PU1 and PU4 respectively according to the ratio of palm kernel oil polyol (PKO-p) with polyethylene glycol (PEG) as the chain extender to 2,4-methylene diphenyl diisocyanate (MDI). After that, lithium trifluoromethanesulfonate (LiCF3SO3) salt as the charge carrier was added to the system with different percentage at room temperature. The palm-based polymer electrolyte was casted onto teflon plate via solution casting technique and later was characterised by electrochemical impedance spectroscopy (EIS) to obtain ionic conductivity. The presence of PU-LiCF3SO3 complexes were observed by attenuated total reflection fourier transform infrared (ATR-FTIR) spectroscopy. Differential scanning calorimeter (DSC) was used to study the thermal property of the PU electrolyte. The highest conductivity achieved was 1.55×10-5 S cm-1 at 30 wt.% of LiCF3SO3 at room temperature. Infrared analyses showed the interaction between lithium ions and amine group (-N-H) at (3600-3100 cm-1), carbonyl group (-C=O) at (1750-1650 cm-1) and ether group (-C-O-C-) at (1150-1000 cm-1).
Ionic Conductivity via Quantum Mechanical Tunneling in NH4NO3 Doped Carboxymethyl Cellulose Solid Biopolymer Electrolytes
Authors: Kamarudin Khadijah Hilmun , Mohamad Isa Mohd Ikmar Nizam
Published: June 2015

Carboxymethyl cellulose–NH4NO3 solid biopolymer electrolyte films were prepared by solution casting technique. Ammonium nitrate (NH4NO3) with 5–50 wt.% were dissolved in disparate carboxymethyl cellulose (CMC) solution, respectively. The electrical properties and conduction mechanism of electrolyte films have been revealed by employing electrical impedance spectroscopy in the frequency range of 50 Hz to 1 MHz within the temperature range of 303 K to 353 K. The ionic conductivity was observed to be influenced by the NH4NO3 concentration. The conductivity–temperature relationship is Arrhenius. From dielectric loss variation with frequency, the power law exponent was obtained. The temperature dependence of the power law exponent for CMC– NH4NO3 system can be represented by the quantum mechanical tunneling (QMT) model.
Effect of Sintering on Structural and Transport Properties on Nanosized Pr0.85Na0.15MnO3
Authors: Ng Siau Wei , Pah Lim Kean , Halim S.A. , Jumiah Hassan , Gan Albert  H.M. , Chin Hui Wei , Cheong Kuen Hou
Published: June 2015

We have investigated the structural, microstructure and electrical transport properties of nanosized Pr0.85Na0.15MnO3 (PNMO) synthesized by sol-gel technique and sinter from 600°C to 1000°C. The grain size increases from 67 nm (S600) up to 284 nm (S1000) due to the grain growth during heat treatment. XRD showed that single phase orthorhombic crystal structure of PNMO is fully forms started at 600°C. The resistivity decreased with the increased of grain size and crystallite size due to the reduction of grain boundary effect (dead magnetic layer) which improved their grain conductivity.All samples showed semiconductor behavior where their metal insulator transition temperatures (TMIT) were estimated to be lower than 80K.
RETRACTED: Fabrication and Characterization of Nanospinel ZnCr2O4 Using Thermal Treatement Method
Authors: Gene Salahudeen A. , Saion Elias B. , Shaari Abdul Halim , Kamarudeen Mazliana A. , Al-Hada Naif Mohammed
Published: June 2015

RETRACTED PAPER: The fabrication of nanospinel zinc chromite (ZnCr2O4) crystals by the means of thermal treatment method from an aqueous solution containing metal nitrates, polyvinyl pyrrolidone (PVP), and deionized water was described in this study. The samples were calcined at various temperatures ranging from 773 to 973 K for the decomposition of the organic compounds and crystallization of the nanocrystals. PVP was used as capping agent to control the agglomeration of the particles. The characterization studies of the fabricated samples were carried out by X-ray diffraction spectroscopy (XRD), transmission electron microscopy (TEM), energy dispersed X-ray spectroscopy (EDX) and electron spin resonance spectroscopy (ESR). The corresponding peaks of Zn, Cr and O were observed in the EDX spectrum of the sample which confirms the formation of ZnCr2O4. The XRD patterns also confirmed the formation of the single faced nanocrystallines of spinel ZnCr2O4 with a face-centered cubic structure. The average particle size of the synthesized crystals was also determined from the XRD patterns using the Scherers formula which shows that the crystallite sizes increases with increase in calcination temperature and was in good agreement with the TEM images which shows cubical ZnCr2O4 nanocrystals with uniform morphology and particle size distributions. The ESR spectra confirmed the existence of unpaired electron in the fabricated samples and the increase in g-factor and decreases in resonant magnetic field (Hr) were observed as the calcination temperature increases.
Effect of Mixed-Phase TiO2/PVA Nanofibers on the Degradation on Methyl Orange
Authors: Mohammed Lot Norizan , Rashid S. Nafisah Md. , Jais Umi Sarah , Abd Rahman M. Kamil
Published: June 2015

We report on the synthesis of nanostructured TiO2 for various structural phases and observed the rate of degradation of methyl orange (MO) upon UV irradiation. Mixed phase nanocrystalline TiO2 at temperature of 800°C shows higher rate of degradation of MO with the rate of 0.0203/min compared to other phases. This rate corresponds to the percentage of MO degradation of 58.85%, 71.69%, 86.25% and 91.82% for duration of 30, 60, 90 and 120 min of UV irradiations, respectively. The TiO2 powder was prepared using titanium (IV) butoxide as the precursor via sol gel process. The samples were characterized using X-ray diffractometer (XRD) and field emission scanning electron microscopy (FESEM). The rate of degradation of MO after UV exposure was measured using UV-Vis spectrophotometer. The first order reaction rate constants (kapp) of anatase; mixed-phase; and rutile phases were 0.0130, 0.0203 and 0.0029, respectively, which shows that mixed-phase TiO2 has higher kapp value indicating higher rate of degradation. The PVA/TiO2 nanofibers were produced via electrospinning technique and similar tests on the nanofibers were conducted.Energy dispersive X-ray spectroscopy (EDX) indicates significant presence of TiO2 is in nanofibers and the average diameter of the nanofibers was 600 nm.
Influence of Zirconium Doped Titanium Oxide towards Photocatalytic Activity of Paraquat
Authors: Badli Nur Afiqah , Ali Rusmidah , Yuliati Leny
Published: June 2015

The heterogeneous photocatalyst based on titanium dioxide has been widely investigated as an attractive treatment method for water pollution. Herbicide like paraquat dichloride is one of the toxic organic pollutants which is harmful to human and animal and is still being used in agricultural sectors. TiO2 doped with zirconium element has been proven to enhance the photocatalytic activity of TiO2 from the previous study. Therefore in this study, photodegradation of paraquat dichloride (1,1-dimethyl-4,4’-bipyridylium dichloride) under UV irradiation was studied using TiO2 and Zr doped TiO2 prepared via modified sol gel method as photocatalysts. The photocatalytic activity was increased in the presence of zirconium as dopant compared to TiO2. Various calcination temperatures range from 450°C to 1000°C and dopant ratio (10:90, 20:80 and 30:70) were applied to optimize the working condition. Significant enhancement was obtained using Zr doped TiO2 (20:80) calcined at 750°C which gave 79.63% degradation of paraquat compared to TiO2 calcined at 450°C and 750°C which were 22.31% and 11.57%. X-ray diffraction (XRD) diffratogram of Zr doped TiO2 photocatalyst showed a mixture of anatase/rutile TiO2 crystalline structures at 750°C. Nanosized photocatalyst with spherical morphology was observed by Field Emission Scanning Electron Microscopy (FESEM). The surface area measured by nitrogen adsorption analysis showed an increment from 8.43m2/g to 46.35m2/g compared to undoped catalyst calcined at 450°C.
Influence of Samarium on the Optical Response of Zinc Phosphate Glass
Authors: Mohamad Azmi Siti Amlah , Sahar M.R. , Arifin Ramli , Ghoshal Sib Krishna
Published: June 2015

Samarium doped zinc phosphate glasses of the form 40ZnO-(60-x) P2O5-xSm2O3, with 1.0 ≤ x ≤ 5.0 mol% were prepared using the melt quenching method. The XRD patterns confirmed the amorphous nature of the glass. The Archimedes method was used to measure the density, which was used to calculate the molar volumes. The density was found to vary in the range of 2.839 to 3.138 gm/cm3 while the molar volume varied between 40.80 and 42.21cm3/mol. The effect of samarium on the optical absorption and emission characteristics were examined. The absorption spectra exhibit two dominant absorption peaks corresponding to the transitions from 6H5/2 ground state to 4I11/2 and 4F7/2 excited states, respectively. Photoluminescence emission consisting of 4G5/2 à 6H5/2, 6H7/2, 6H9/2 and 6H11/2 transitions display significant enhancement with the increase of Sm3+ concentration up to 3.0 mol% followed by a rapid quenching beyond this concentration which is ascribed to the nonradiative energy transfer and multi-phonon relaxation processes.
Theoretical Studies on Optical Phonon and Surface Phonon Polariton of Wurtzite AlInN Alloys
Authors: Yew Pauline , Sai Cheong Lee , Shiong Ng Sha , Tiem Leong Yoon , Abu Hassan Haslan
Published: June 2015

The lattice vibrational properties of wurtzite ternary mixed crystal aluminium indium nitride (AlxIn1-xN) are investigated thoroughly using modified random element iso-displacement (MREI) model and Born-Huang procedure. MREI model, which considers the nearest neighbour interactions, is used to predict the composition dependence of longitudinal and transverse optical phonon frequencies. For AlxIn1-xN alloy, oscillator strength of its weak mode is sufficiently significant for composition range of 0 < x < 0.4. As a result, AlxIn1-xN alloy is deduced to exhibit mixed-mode behaviour. Finally, the calculated dielectric functions for the entire composition range (0 < x < 1) are used to simulate the surface phonon polariton characteristics of the AlxIn1-xN alloy.
Catalytic CO2/H2 Methanation Reaction over Alumina Supported Manganese/Cerium Oxide Based Catalysts
Authors: Mat Rosid Salmiah Jamal , Wan Abu Bakar Wan Azelee , Ali Rusmidah
Published: June 2015

The methanation reaction is a promising method for the purification of natural gas, in which the acid gases of CO2, is eliminated by catalytic conversion. The advantage of catalytic technology is the utilization of CO2 present in the production of methane gas. The used of alumina supported cerium oxide as the based catalyst in CO2/H2 methanation reaction have been investigated in this research by using manganese as the dopant and ruthenium as the co-dopant via wet impregnation technique. The series of cerium oxide catalysts were calcined at 400 °C for 5 hours had been prepared at the screening stage. Then, the catalysts were optimized by different calcination temperatures and different based oxide loadings. The potential catalysts of Ru/Mn/Ce (5:35:60)/Al2O3 calcined at 700 °C gave 100 % of CO2 conversion by using FTIR and yielded about 24 % of CH4 respectively at reaction temperature of 400 °C. X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM) showed that the supported catalysts were amorphous in structure. FESEM analysis illustrated the surface of the catalysts were covered with small and dispersed spherical particles. EDX analysis revealed that there was 1.02 % reduction of Ru in the Ru/Mn/Ce (5:35:60)/Al2O3 used catalysts compared to fresh catalysts. Meanwhile NA analysis showed that Ru/Mn/Ce (5:35:60)/Al2O3 catalysts attained surface area of 143.10 m2/g respectively.
A New Empirical Equation for Estimating Specific Surface Area of Supercapacitor Carbon Electrode from X-Ray Diffraction
Authors: Deraman Mohamad , Daik Rusli , Soltaninejad Sepideh , Nor Najah Syahirah Mohd , Awitdrus  , Farma Rakhmawati , Mamat Nurul Fatin , Basri Nur Hamizah , Othman Mohd Amir Radhi
Published: June 2015

Interest in research of supercapacitor has been in increasing trend because of high demand of supercapacitor application as energy storage device in both systems that require low and high power-energy usage. For supercapacitor using porous carbon electrodes, the energy storage mechanism involves the electrolyte ions in electrodes pores and electronic charges in electrodes to form electric double layers at the electrode-electrolyte interface without undergoes any chemical reaction. The specific surface area of porous electrodes, which affect the performance of supercapacitor, have been widely investigated by many researchers using the nitrogen adsorption-desorption measurement. However, despite its simplicity the X-ray diffraction method is rarely found being used to determine the specific surface area of porous electrodes. Therefore, in the present paper, we propose a new equation which expressed the specific surface area of electrodes as a function the electrode structural parameters obtained from the X-ray diffraction data, and duration of activation time employed during the electrode preparation. This equation is found to produce a satisfactory result and is expected to be beneficial for studying supercapacitor electrode materials.
Optical Characteristics of Erbium-Doped SiO2/PVA Electrospun Nanofibers
Authors: Abd-Rahman M. Kamil , Suhaimi N.F.M. , Edwin Evy Evana , Dian Winnie , Abdul Halim Nur Hanis
Published: June 2015

This paper reports on the fabrication and optical characteristics of erbium-doped silica/PVA nanofibers via sol gel and electrospinning techniques. Silica glass, PVA (polyvinyl alcohol) and SiO2/PVA composites displayed 85% to 90% transparent across 300 2000 nm wavelength range. The transmission spectra were measured using Cary 5000 UV-Vis-NIR spectrophotometer. Silica was synthesized using TEOS (tetraethylorthosilicate) as the precursor, while PVA solution comprised of 7.0 wt% in H2O. The compositional ratios of SiO2:PVA were from 6:4 to 1:9 and were doped with 0.2% to 0.6% of erbium. Suitable viscosities of Er3+-doped SiO2:PVA solutions were electrospun into mesh of long strands nanofibers. Morphological and material compositions in the nanofibers were analysed using FESEM (field-emission scanning electron microscopy) and EDX (energy-dispersive X-ray spectroscopy). Er3+-doped SiO2:PVA thin films were coated on fused-silica glass substrates via spin coating and were characterized for their refractive indices, optical transmission, and fluorescence using M-line technique, UV-Vis-NIR spectrometer and photoluminescence spectrophotometer, respectively. Lower ratios of silica to PVA solutions results in higher viscosities and produced more uniform nanofiber structures of diameters around 100 nm with lesser beads. The refractive index of 1.61 for Er-doped SiO2:PVA (1:9) thin film was measured with TE polarized 632.8 nm wavelength laser and the index shows to be higher for more content of PVA in the glass/polymer composites. The 0.4% of Er3+ in SiO2:PVA composite produced the highest luminescence intensity at 605 nm when excited with 514 nm source. Higher doping content caused ion clustering effect and leads to concentration quenching, hence decreased in the emission intensity.
Photoconductivity of Pharma-Grade ZnO under UVA and White Light Exposure
Authors: Ann Ling Chuo , Mahmud Shahrom , Bakhori Siti Khadijah Mohd , Sirelkhatim Amna
Published: June 2015

In this study, we investigated the photoconductivity of pharma-grade zinc oxide (ZnO) which was excited under ultraviolet - long wavelength (UVA) and white light illumination. The morphological structures of ZnO were studied using field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The ZnO sample was composed of micro/nanorods, slabs, tripods, tetrapods and irregular-shaped particles. The energy-dispersive X-ray spectroscopy (EDS) result revealed the high purity of ZnO, with the relative O/Zn atomic ratio lower than 1. The absorption spectrum of ZnO suspension was performed using UV-Visible spectroscopy. ZnO sample exhibited strong absorption at 387 nm, corresponding to optical bandgap of 3.23 eV. The ZnO powder was converted into pellets to study its photoconductivity under different intensity of UVA (0.5-2.0 mW/cm-2) and white light exposure (200-1000 lux) from conventional fluorescent lamp. The significant increase in surface conductivity of the ZnO pellets could be due to UVA illumination that produces photo-generated charge carriers on the surface of ZnO pellet. There was a small persistency of current flow after the UVA exposure was terminated. Under the white light exposure, the surface conductivity was slightly higher than that of dark condition. This is probably due to the small amount of defects, particularly oxygen vacancies and zinc interstitials that produce some light-generated charges on the ZnO crystal structures. The white light exposure may cause the excitation of electrons from the defects energy level to the conduction band, this being the underlying cause for the increase in the conductivity. ZnO pellet exhibited a dramatic enhancement of photoconductivity under UVA illumination if compared with small improvement of photoconductivity under white light exposure.
Transport Critical Current Density and Flux Pinning Enhancement in Nano-Sized PbO and HfO2 Added (Bi1.6Pb0.4)Sr2Ca2Cu3O10 Superconductor
Authors: Yahya Nabil A.A. , Abd-Shukor R.
Published: June 2015

A comparative study on the effect of PbO (10-30 nm) and HfO2 (60-80 nm) additions on the superconducting properties of (Bi1.6Pb0.4)Sr2Ca2Cu3O10 ((Bi,Pb)-2223) superconductor in the bulk form was carried out. The structure and the microstructure of prepared samples were examined by powder XRD and SEM, respectively. The transition temperature Tc and critical current density Jc was determined by standard dc four-probe method. SEM micrographs showed a homogeneous distribution of Pb and Hf in the samples. It was observed that PbO and HfO2 additions enhanced Jc for all added samples. Jc was the highest for x= 0.05 wt. % of PbO (1130 mA/cm2 at 77 K and 1930 mA/cm2 at 30 K) and HfO2 (900 mA/cm2 at 77 K and 1760 mA/cm2 at 30 K) addition. This study showed that the addition of PbO and HfO2 nanopowder provided extra flux pinning centers in the (Bi, Pb)-2223. PbO with smaller particle size showed higher Jc compared with HfO2 which has a larger particle size.
H2-Assisted Chemical Reaction for Green-Kerosene Production
Authors: Dujjanutat Praepilas , Neramittagapong Arthit , Kaewkannetra Pakawadee
Published: June 2015

In this work, the effect of catalysts, temperatures and different types of vegetable oil on the production of synthetic bio-fuel via a hydro-processing process called as a hydro-cracking reaction by high pressure pack bed reactor is investigated. Firstly, H2gas (95% purity) was fed into the reactor together with palm oil under two different catalysts (Pd/Al2O3and Pt/Al2O3) separately packed in the reactor. The effect of different temperatures (500°C and 530°C) was investigated and the pressure was applied and maintained at 5 MPa for both temperatures. The results revealed that, when the Pd/Al2O3catalyst was used the highest bio-fuel (approximately 90% at 500°C) after distillation can be produced. Then, palm oil and soybean oil were used to compare in the efficiency of kerosene fuel production. The reaction was operated at 500°C, 5 MPa under H2pressure on the presence of 0.5% Pd/Al2O3. The bio-fuel achieved the highest yields at about 88% and 69% in cases of palm oil and soybean oil. It was also classified as kerosene yield approximately 70% when palm oil was used as a feed stock and at about 55% for soybean oil. Some properties of the kerosene product were characterised. The viscosities were obtained at 1.75 and 1.84 mm2/s and provided 43.06 and 45.85 MJ/kg of heating combustion values when palm oil and soybean oil were used. In addition, the carbon distribution of the synthetic kerosene produced from palm oil was clearly shown to be in the range of C11-C13which is similar to kerosene fuel obtained from petroleum.
Morphology and Structure of Nb3Sn Diffusion Layers in Superconductors with Tubular Nb Filaments
Authors: Popova Elena N. , Deryagina I.L. , Patrakov E.I. , Valova-Zaharevskaya E.G.
Published: June 2015

The structure and morphology of Nb3Sn layers in superconducting Nb/Cu-Sn composites with ring (tubular) Nb filaments have been studied by transmission (TEM) and scanning (SEM) electron microscopy after various regimes of diffusion annealing. It is demonstrated that the tubular geometry of Nb filaments, in which Sn diffuses from the bronze matrix both from inside and outside, ensures practically complete transformation of Nb into the superconducting Nb3Sn phase. Besides, at certain regimes of the diffusion annealing this geometry enables the improvement of the superconducting layers morphology compared to that of wires with continuous filaments, namely, to obtain wide Nb3Sn layers with fine equiaxed grains and to avoid the formation of columnar grains, which promotes enhanced current-carrying capacities of the wires.
Observation of Phase Transformation in Shape Memory Alloy NiTi Wire during In Vitro Simulation of Orthodontic Treatment
Authors: Rudolf Rebeka , Ferčec Janko
Published: June 2015

The aim of this study was to simulate the different loadings on NiTi Shape Memory Alloy in the form of wire that occurs in orthodontic praxis. Our main goals were to detect and determine the beginning of the stress-induced transformation from the austenite to martensite phases and to indicate the transformation plateau at different deformations during orthodontic treatment usingin-vitrosimulation. For this reason, we developed two prototype devices forin-situsimulation of orthodontic treatment by which we measured the electrical resistance and hardness. Accompanying these two properties and the microstructure observations of loaded wires by Transmission Electron Microscopy enabled us to detect successfully the stabilized stress-induced martensite due phase transformation. We found out that transformation depends strongly on the type of loading.
Heat and Mass Transfer and Energy Aspects in Combined Infrared-Convective Drying of Bee-Pollen
Authors: Brandão R.J. , Santos L.D.M. , Marques L.G. , Prado M.M.
Published: June 2015

A hybrid drying process based on the application of infrared (IR) radiation combined to non-heated air flow was proposed for bee-pollen drying. The IR source was located at a distance of 32 cm from the samples. Experiments in the hybrid dryer were conducted with pollen grains arranged in a single layer and exposed to three radiation intensity levels (150, 300 and 450 W/m2) and three air velocity levels (1.0, 2.0 and 3.0 m/s) at 25°C. The surface temperature of the material was measured during drying through an optical pyrometer. The effects of the process parameters on the drying kinetics and specific energy consumption were evaluated. Experimental results showed that for any particular air velocity increasing IR heat flux led to an intensification of mass transfer rate, decreasing drying time and thus reducing energy consumption. Minimum energy consumption in hybrid frying of pollen was associated with the application of the highest radiation intensity and lowest air velocity. It was also found that cooling effect increased with air velocity, which resulted in a decreased driving force for mass transfer and increased drying time and energy consumption.
An Ontario kimberlite occurrence discovered by application of the glaciofocus method to a study of the Munroe Esker
Authors: Lee H A
Published: June 2015

A kimberlite dyke was discovered in northern Ontario by application of the glaciofocus method of tracing mineral and rock fragments in an esker to their bedrock source.
Stratigraphy, depositional environment, and tectonic setting of the Upper Triassic to Middle Jurassic rocks of the Chilcotin Ranges, southwestern British Columbia
Authors: Umhoefer P J , Tipper H W
Published: June 2015

Plusieurs riches assemblages de radiolaires bien préservés de l'Hettangien et du Sinémurien ont été extraits de concrétions calcaires contenues dans la Formation de Sandilands, dans les îles de la Reine- Charlotte. Des
récoltes effectuées dans les coupes stratigraphiques de la pointe Kennecott (nord-ouest de l'île Graham) et de l'île Kunga permettent de définir le cadre principal de la présente étude. D'autres récoltes effectuées dans des affleurements moins bien
exposés ont fourni des données complémentaires pour certains intervalles stratigraphiques. Des ammonites intimement associées aux échantillons de radiolaires assurent un excellent contrôle biochronologique à la présente étude.
Une nouvelle zonation basée sur les associations unitaires (AU; Guex, 1977) est proposée pour l'Hettangien et le Sinémurien. Une base de données recensant la présence ou l'absence de 119 espèces de radiolaires dans une succession verticale de 95 horizons, ou
échantillons, répartis dans 15 coupes stratigraphiques a permis de construire une séquence de 25 associations unitaires. Ces associations unitaires ont été regroupées en sept biochronozones. Cinq d'entre elles sont des zones d'associations unitaires (ZAU) au sens strict
et les trois autres sont des zones d'intervalle (ZI), chacune de ces zones étant définie par des paires d'espèces en relation de coexistence et par l'ensemble des espèces caractéristiques.
La séquence des ammonites associées aux faunes de radiolaires nous permettent d'établir que la Zone à Canoptum merum (ZI) est de l'Hettangien basal; la Zone à Protokatroma aquila(ZI) est assignable au sommet de l'Hettangien inférieur; la Zone à Pantanellium browni
(ZAU) est de l'Hettangien moyen à supérieur; la Zone à Crucella hettangica (ZAU) s'étend de l'Hettangien sommital au Sinémurien basal; la Zone à Parashuum simplum (ZAU) est du Sinémurien inférieur; la Zone à Canutus rockfishensis-Wrangellium thurstonense
(ZAU) correspond à la base du Sinémurien supérieur; et la Zone à Jacus (?) sandspitensis (ZAU) est assignable au Sinémurien supérieur.
Les radiolaires de l'Hettangien et du Sinémurien ont des affinités téthysiennes et ils sont comparables à ceux que l'on connaît en Bavière, dans la région méditerranéenne, au Japon et en Nouvelle-Zélande.
Une nouvelle sous-famille (Charlotteinae), quatorze nouveaux genres (Amuria, Beatricea, Charlottea, Danubea, Empirea, Foremania, Protokatroma, Solidea, Sophia, Teesium, Thurstonia, Tozerium, Trexus et Udalia) et soixante-huit nouvelles espèces de radiolaires sont décrits
ici.
Radiolaires des complexes d'accrétion de la Cordillère canadienne (Colombie-Britannique)
Authors: Cordey F
Published: June 2015

Ninety-two collections of radiolarian faunas have been recovered from siliceous strata of the Cache Creek, Bridge River, and Hozameen accretionary complexes in the Coast and Intermontane Belt of southern British Columbia, and from local units comprising the
Chilliwack Group, the Camp Cove Formation, and chert clasts from regional Cretaceous conglomerates.
Radiolarian fauna range in age from Late Devonian to Middle-Late Jurassic, including Early Carboniferous, Early and Late Permian, Middle and Late Triassic, Early and Middle Jurassic. The Bridge River Complex, which contains radiolarians from Early Carboniferous to Middle-Late Jurassic, almost spans
this entire age range. Taxonomic descriptions comprise 78 genera and 172 species, including 4 new genera, 24 new species and 38 new morphotypes.
Most of the radiolarian associations were extracted from radiolarian ribbon chert, although some of the youngest productive samples are from siliceous argillite associated with fine- or coarse-grained clastic sedimentary strata. Radiolarian chert, a rock-type resulting from the accumulation of
radiolarian shells, is widespread in time and space in the terranes studied. This favours the hypothesis of radiolarian planktonic predominance in proto-Pacific ocean basins of Late Paleozoic and Mesozoic times
Most of radiolarian associations discovered in chert-bearing terranes of southern British Columbia have low paleolatitude faunal affinities. Some of them are known only from western Pacific terranes such as those in Japan, not only in Permian or Triassic times, but also in the Middle-Late Jurassic
when these terranes were supposedly closer to the west American margin(s). This favours the idea of paleoenvironmental and/or paleolongitudinal controls in addition to proposed paleolatitudinal differentiation of radiolarian fauna in the Mesozoic.
Twenty-eight plates illustrate 313 micrographs of radiolarians and 15 micrographs of conodonts (identified by M.J. Orchard, Geological Survey of Canada).
Molecular characterisation of Mycoplasma species isolated from the genital tract of Dorper sheep in South Africa
Authors: Kalshingi Habu A. , Bosman Anna-Mari , Gouws Johan , Van Vuuren Moritz
Published: June 2015

Biochemical and molecular analysis were conducted on 34 strains of Mycoplasma species isolated between 2003 and 2009 from the genital tract of clinically healthy Dorper sheep and sheep with ulcerative vulvitis and balanitis. Earlier publications identified the causative agent as Mycoplasma mycoides mycoides large colony (MmmLC) and Arcanobacterium pyogenes. The aims of the study were to characterise Mycoplasma species isolated from the genital tract of Dorper sheep with polymerase chain reaction assay, cloning and gene sequencing. Basic Local Alignment Search Tool (BLAST) results revealed six predominant Mycoplasma species: Mycoplasma arginini, Mycoplasma bovigenitalium, Arcanobacterium laidlawii, MmmLC, Mycoplasma sp. ovine/caprine serogroup II and M. canadense. Sequencing of the 34 isolates were analysed using phylogenetic methods, and 18 (50%) were identified as M. arginini with 99% – 100% similarity to M. arginini from England and Sweden. Six isolates showed 99% similarity to M. bovigenitalium strains from Turkey and Germany. Two isolates had 99% similarity to an M. sp. ovine/caprine sero group II from the United Kingdom. BLAST for two isolates revealed 99% similarity to Acholeplasma laidlawii from India, another two were 99% similar to MmmLC strain from Sweden, two showed 98% similarity to Mycoplasma sp. Usp 120 from Brazil, and two isolates have a 97% – 99% similarity to M. mm. Jcv1 strain from the United States of America. Finally, one isolate showed similarity of 99% to Mycoplasma canadense strain from Italy. The findings support the hypothesis that ulcerative vulvitis and balanitis of Dorper sheep in South Africa (SA) is a multifactorial disease with involvement of different Mycoplasma species.
Storying Ubuntu as a rainbow nation
Authors: Buqa Wonke
Published: June 2015

South Africa is often referred to as the �Rainbow Nation�. This term was coined by Desmond Tutu during the advent of democracy in the country. Tutu stated: �They tried to make us one colour: purple. We say we are the rainbow people! We are the new people of the new South Africa!� This article seeks to answer the question as to whether the Rainbow Nation is a true reflection of Ubuntu in South Africa or whether it is just idealism.
An Improved Breast Epithelial Sampling Method for Molecular Profiling and Biomarker Analysis in Women at Risk for Breast Cancer
Authors: Danforth David N. , Warner Andrew C. , Wangsa Darawalee , Ried Thomas , Duelli Dominik , Filie Armando C. , Prindiville Sheila A.
Published: June 2015

Background

There is a strong need to define the molecular changes in normal at-risk breast epithelium to identify biomarkers and new targets for breast cancer prevention and to develop a molecular signature for risk assessment. Improved methods of breast epithelial sampling are needed to promote whole-genome molecular profiling, increase ductal epithelial cell yield, and reduce sample cell heterogeneity.

Methods

We developed an improved method of breast ductal sampling with ductal lavage through a 22-gauge catheter and collection of ductal samples with a microaspirator. Women at normal risk or increased risk for breast cancer were studied. Ductal epithelial samples were analyzed for cytopathologic changes, cellular yield, epithelial cell purity, quality and quantity of DNA and RNA, and use in multiple downstream molecular applications.

Results

We studied 50 subjects, including 40 subjects at normal risk for breast cancer and 37 subjects with non-nipple aspirate fluid-yielding ducts. This method provided multiple 1.0 mL samples of high ductal epithelial cell content (median ≥8 samples per subject of ≥5,000 cells per sample) with 80%–100% epithelial cell purity. Extraction of a single intact ductal sample (fluid and cells) or the separate frozen cellular component provided DNA and RNA for multiple downstream studies, including quantitative reverse transcription-polymerase chain reaction (PCR) for microRNA, quantitative PCR for the human telomerase reverse transcriptase gene, whole-genome DNA amplification, and array comparative genomic hybridization analysis.

Conclusion

An improved breast epithelial sampling method has been developed, which should significantly expand the acquisition and biomarker analysis of breast ductal epithelium in women at risk for breast cancer.
Similarity of Serum and Plasma Insulin-like Growth Factor Concentrations
Authors: Houghton Lauren C. , Pollak Michael N. , Tao Yuzhen , Tu Ying Gang , Black Amanda , Bradwin Gary , Hoover Robert N. , Troisi Rebecca
Published: June 2015

Background

Insulin-like growth factors (IGFs) are implicated in many normal physiological processes and pathological states, including cancer. For large consortia projects, it may be necessary to make comparisons among studies with different specimens that were not collected specifically to optimize the measurement of IGFs.

Objective

This study aimed to compare IGFs in matched serum and plasma samples.

Methods

We measured IGF-I, IGF-II, insulin-like growth factor-binding protein (IGFBP)-3, C-peptide, and leptin in serum and ethylenediaminetetraacetic–containing-plasma samples obtained concurrently from 30 healthy women aged 64–80 years in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial using chemiluminescent or colorimetric enzyme-linked immune assays. Coefficients of variation (CVs) and correlations were determined.

Results

Intraassay CVs ranged from 0.4% for IGFBP-3 to 10% for IGF-II. Mean concentrations of all analytes were higher in the serum, but the differences in mean concentrations of the analytes between serum and plasma were all <11%. Concordance correlation coefficients of matched serum/plasma specimens were 0.92, 0.91, 0.82, 0.96, and 0.99 for IGF-I, IGFBP-3, IGF-II, C-peptide, and leptin, respectively.

Conclusion

IGF concentrations measured in serum and plasma are highly correlated but are consistently slightly higher in serum, suggesting that IGF values should be corrected for systematic bias, particularly in consortial efforts when pooling data derived from different specimens.
Mechanical blossom thinning of apples and influence on yield, fruit quality and spur leaf area
Authors: McClure Kendra A. , Cline John A.
Published: June 2015

McClure, K. A. and Cline, J. A. 2015. Mechanical blossom thinning of apples and influence on yield, fruit quality and spur leaf area. Can. J. Plant Sci. 95: 887–896. Apple (Malus×domestica Borkh.) trees tend to crop heavily, which often makes crop load adjustment necessary. This can now be achieved as early as bloom by mechanical removal/thinning of blossoms. High-density Empire/M.26 and Royal Gala/M.26 apple trees were mechanically (MBT) and hand blossom thinned (HBT) in 2010 and 2011, respectively, and their effects on fruit set, subsequent hand thinning, final crop load, and spur leaf area were measured. In both years, MBT effectively thinned trees and reduced fruit set, but did not reduce the requirement for follow-up hand fruitlet thinning after June drop in 2011. In 2010, harvest yields for MBT treatments decreased, while weight and diameter increased. In 2011, most harvest and fruit quality parameters were unaffected by thinning. Trees that were mechanically thinned had significantly reduced spur leaf area, but were similar to unthinned control trees with respect to many of the yield and quality parameters measured. Mechanical blossom thinning is a new crop load management option for apple growers looking to supplement more traditional chemical and hand thinning techniques.